13688561003

Committed 06 Mar 2025 12:41AM UTC coverage: 88.093% (-0.004%) from 88.097%

Build # 13688561003

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push

github

Committed by

web-flow

Commit Message

Add representation of `box` (#13869)

* Add representation of `box`

This adds in the base `box` control-flow construction, with support for
containing instructions and having a literal delay, like the `Delay`
instruction.

This supports basic output to OpenQASM 3, QPY and some rudimentary
support in the text and mpl drawers.  The transpiler largely handles
things already, since control flow is handled generically in most
places.

Known issues:

- We expect this to be able to accept stretches in its duration, just as
  `Delay` can, which will need a follow-up.
- We expect `Box` to support "annotations" in a future release of
  Qiskit.
- There is currently no way in OpenQASM 3 to represent a qubit that is
  idle during a `box` without inserting a magic instruction on it.
- IBM backends don't claim support for `box` yet, so `transpile` against
  a backend will fail, though you can modify the `Target` to add the
  instruction manually.

Add tests of box

* Add QPY backwards-compatibility test

* Add `BoxOp.body` getter and tests

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48.96

/qiskit/visualization/circuit/matplotlib.py

# This code is part of Qiskit.
#
# (C) Copyright IBM 2017, 2018.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.

# pylint: disable=invalid-name,inconsistent-return-statements

"""mpl circuit visualization backend."""

import collections
import itertools
import re
from io import StringIO

import numpy as np

from qiskit.circuit import (
    QuantumCircuit,
    Qubit,
    Clbit,
    ClassicalRegister,
    ControlledGate,
    Measure,
    ControlFlowOp,
    BoxOp,
    WhileLoopOp,
    IfElseOp,
    ForLoopOp,
    SwitchCaseOp,
    CircuitError,
)
from qiskit.circuit.controlflow import condition_resources
from qiskit.circuit.classical import expr
from qiskit.circuit.annotated_operation import _canonicalize_modifiers, ControlModifier
from qiskit.circuit.library import Initialize
from qiskit.circuit.library.standard_gates import (
    SwapGate,
    RZZGate,
    U1Gate,
    PhaseGate,
    XGate,
    ZGate,
)
from qiskit.qasm3 import ast
from qiskit.qasm3.exporter import _ExprBuilder
from qiskit.qasm3.printer import BasicPrinter

from qiskit.circuit.tools.pi_check import pi_check
from qiskit.utils import optionals as _optionals

from .qcstyle import load_style
from ._utils import (
    get_gate_ctrl_text,
    get_param_str,
    get_wire_map,
    get_bit_register,
    get_bit_reg_index,
    get_wire_label,
    get_condition_label_val,
    _get_layered_instructions,
)
from ..utils import matplotlib_close_if_inline

# Default gate width and height
WID = 0.65
HIG = 0.65

# Z dimension order for different drawing types
PORDER_REGLINE = 1
PORDER_FLOW = 3
PORDER_MASK = 4
PORDER_LINE = 6
PORDER_LINE_PLUS = 7
PORDER_BARRIER = 8
PORDER_GATE = 10
PORDER_GATE_PLUS = 11
PORDER_TEXT = 13

INFINITE_FOLD = 10000000


@_optionals.HAS_MATPLOTLIB.require_in_instance
@_optionals.HAS_PYLATEX.require_in_instance
class MatplotlibDrawer:
    """Matplotlib drawer class called from circuit_drawer"""

    _mathmode_regex = re.compile(r"(?<!\\)\$(.*)(?<!\\)\$")

    def __init__(
        self,
        qubits,
        clbits,
        nodes,
        circuit,
        scale=None,
        style=None,
        reverse_bits=False,
        plot_barriers=True,
        fold=25,
        ax=None,
        initial_state=False,
        cregbundle=None,
        with_layout=False,
        expr_len=30,
    ):
        self._circuit = circuit
        self._qubits = qubits
        self._clbits = clbits
        self._nodes = nodes
        self._scale = 1.0 if scale is None else scale

        self._style = style

        self._plot_barriers = plot_barriers
        self._reverse_bits = reverse_bits
        if with_layout:
            if self._circuit._layout:
                self._layout = self._circuit._layout.initial_layout
            else:
                self._layout = None
        else:
            self._layout = None

        self._fold = fold
        if self._fold < 2:
            self._fold = -1

        self._ax = ax

        self._initial_state = initial_state
        self._global_phase = self._circuit.global_phase
        self._expr_len = expr_len
        self._cregbundle = cregbundle

        self._lwidth1 = 1.0
        self._lwidth15 = 1.5
        self._lwidth2 = 2.0
        self._lwidth3 = 3.0
        self._lwidth4 = 4.0

        # Class instances of MatplotlibDrawer for each flow gate - If/Else, For, While, Switch
        self._flow_drawers = {}

        # Set if gate is inside a flow gate
        self._flow_parent = None
        self._flow_wire_map = {}

        # _char_list for finding text_width of names, labels, and params
        self._char_list = {
            " ": (0.0958, 0.0583),
            "!": (0.1208, 0.0729),
            '"': (0.1396, 0.0875),
            "#": (0.2521, 0.1562),
            "$": (0.1917, 0.1167),
            "%": (0.2854, 0.1771),
            "&": (0.2333, 0.1458),
            "'": (0.0833, 0.0521),
            "(": (0.1167, 0.0729),
            ")": (0.1167, 0.0729),
            "*": (0.15, 0.0938),
            "+": (0.25, 0.1562),
            ",": (0.0958, 0.0583),
            "-": (0.1083, 0.0667),
            ".": (0.0958, 0.0604),
            "/": (0.1021, 0.0625),
            "0": (0.1875, 0.1167),
            "1": (0.1896, 0.1167),
            "2": (0.1917, 0.1188),
            "3": (0.1917, 0.1167),
            "4": (0.1917, 0.1188),
            "5": (0.1917, 0.1167),
            "6": (0.1896, 0.1167),
            "7": (0.1917, 0.1188),
            "8": (0.1896, 0.1188),
            "9": (0.1917, 0.1188),
            ":": (0.1021, 0.0604),
            ";": (0.1021, 0.0604),
            "<": (0.25, 0.1542),
            "=": (0.25, 0.1562),
            ">": (0.25, 0.1542),
            "?": (0.1583, 0.0979),
            "@": (0.2979, 0.1854),
            "A": (0.2062, 0.1271),
            "B": (0.2042, 0.1271),
            "C": (0.2083, 0.1292),
            "D": (0.2312, 0.1417),
            "E": (0.1875, 0.1167),
            "F": (0.1708, 0.1062),
            "G": (0.2312, 0.1438),
            "H": (0.225, 0.1396),
            "I": (0.0875, 0.0542),
            "J": (0.0875, 0.0542),
            "K": (0.1958, 0.1208),
            "L": (0.1667, 0.1042),
            "M": (0.2583, 0.1604),
            "N": (0.225, 0.1396),
            "O": (0.2354, 0.1458),
            "P": (0.1812, 0.1125),
            "Q": (0.2354, 0.1458),
            "R": (0.2083, 0.1292),
            "S": (0.1896, 0.1188),
            "T": (0.1854, 0.1125),
            "U": (0.2208, 0.1354),
            "V": (0.2062, 0.1271),
            "W": (0.2958, 0.1833),
            "X": (0.2062, 0.1271),
            "Y": (0.1833, 0.1125),
            "Z": (0.2042, 0.1271),
            "[": (0.1167, 0.075),
            "\\": (0.1021, 0.0625),
            "]": (0.1167, 0.0729),
            "^": (0.2521, 0.1562),
            "_": (0.1521, 0.0938),
            "`": (0.15, 0.0938),
            "a": (0.1854, 0.1146),
            "b": (0.1917, 0.1167),
            "c": (0.1646, 0.1021),
            "d": (0.1896, 0.1188),
            "e": (0.1854, 0.1146),
            "f": (0.1042, 0.0667),
            "g": (0.1896, 0.1188),
            "h": (0.1896, 0.1188),
            "i": (0.0854, 0.0521),
            "j": (0.0854, 0.0521),
            "k": (0.1729, 0.1083),
            "l": (0.0854, 0.0521),
            "m": (0.2917, 0.1812),
            "n": (0.1896, 0.1188),
            "o": (0.1833, 0.1125),
            "p": (0.1917, 0.1167),
            "q": (0.1896, 0.1188),
            "r": (0.125, 0.0771),
            "s": (0.1562, 0.0958),
            "t": (0.1167, 0.0729),
            "u": (0.1896, 0.1188),
            "v": (0.1771, 0.1104),
            "w": (0.2458, 0.1521),
            "x": (0.1771, 0.1104),
            "y": (0.1771, 0.1104),
            "z": (0.1562, 0.0979),
            "{": (0.1917, 0.1188),
            "|": (0.1, 0.0604),
            "}": (0.1896, 0.1188),
        }

    def draw(self, filename=None, verbose=False):
        """Main entry point to 'matplotlib' ('mpl') drawer. Called from
        ``visualization.circuit_drawer`` and from ``QuantumCircuit.draw`` through circuit_drawer.
        """

        # Import matplotlib and load all the figure, window, and style info
        from matplotlib import patches
        from matplotlib import pyplot as plt

        # glob_data contains global values used throughout, "n_lines", "x_offset", "next_x_index",
        # "patches_mod", "subfont_factor"
        glob_data = {}

        glob_data["patches_mod"] = patches
        plt_mod = plt

        self._style, def_font_ratio = load_style(self._style)

        # If font/subfont ratio changes from default, have to scale width calculations for
        # subfont. Font change is auto scaled in the mpl_figure.set_size_inches call in draw()
        glob_data["subfont_factor"] = self._style["sfs"] * def_font_ratio / self._style["fs"]

        # if no user ax, setup default figure. Else use the user figure.
        if self._ax is None:
            is_user_ax = False
            mpl_figure = plt.figure()
            mpl_figure.patch.set_facecolor(color=self._style["bg"])
            self._ax = mpl_figure.add_subplot(111)
        else:
            is_user_ax = True
            mpl_figure = self._ax.get_figure()
        self._ax.axis("off")
        self._ax.set_aspect("equal")
        self._ax.tick_params(labelbottom=False, labeltop=False, labelleft=False, labelright=False)

        # All information for the drawing is first loaded into node_data for the gates and into
        # qubits_dict, clbits_dict, and wire_map for the qubits, clbits, and wires,
        # followed by the coordinates for each gate.

        # load the wire map
        wire_map = get_wire_map(self._circuit, self._qubits + self._clbits, self._cregbundle)

        # node_data per node filled with class NodeData attributes
        node_data = {}

        # dicts for the names and locations of register/bit labels
        qubits_dict = {}
        clbits_dict = {}

        # load the _qubit_dict and _clbit_dict with register info
        self._set_bit_reg_info(wire_map, qubits_dict, clbits_dict, glob_data)

        # get layer widths - flow gates are initialized here
        layer_widths = self._get_layer_widths(node_data, wire_map, self._circuit, glob_data)

        # load the coordinates for each top level gate and compute number of folds.
        # coordinates for flow gates are loaded before draw_ops
        max_x_index = self._get_coords(
            node_data, wire_map, self._circuit, layer_widths, qubits_dict, clbits_dict, glob_data
        )
        num_folds = max(0, max_x_index - 1) // self._fold if self._fold > 0 else 0

        # The window size limits are computed, followed by one of the four possible ways
        # of scaling the drawing.

        # compute the window size
        if max_x_index > self._fold > 0:
            xmax = self._fold + glob_data["x_offset"] + 0.1
            ymax = (num_folds + 1) * (glob_data["n_lines"] + 1) - 1
        else:
            x_incr = 0.4 if not self._nodes else 0.9
            xmax = max_x_index + 1 + glob_data["x_offset"] - x_incr
            ymax = glob_data["n_lines"]

        xl = -self._style["margin"][0]
        xr = xmax + self._style["margin"][1]
        yb = -ymax - self._style["margin"][2] + 0.5
        yt = self._style["margin"][3] + 0.5
        self._ax.set_xlim(xl, xr)
        self._ax.set_ylim(yb, yt)

        # update figure size and, for backward compatibility,
        # need to scale by a default value equal to (self._style["fs"] * 3.01 / 72 / 0.65)
        base_fig_w = (xr - xl) * 0.8361111
        base_fig_h = (yt - yb) * 0.8361111
        scale = self._scale

        # if user passes in an ax, this size takes priority over any other settings
        if is_user_ax:
            # from stackoverflow #19306510, get the bbox size for the ax and then reset scale
            bbox = self._ax.get_window_extent().transformed(mpl_figure.dpi_scale_trans.inverted())
            scale = bbox.width / base_fig_w / 0.8361111

        # if scale not 1.0, use this scale factor
        elif self._scale != 1.0:
            mpl_figure.set_size_inches(base_fig_w * self._scale, base_fig_h * self._scale)

        # if "figwidth" style param set, use this to scale
        elif self._style["figwidth"] > 0.0:
            # in order to get actual inches, need to scale by factor
            adj_fig_w = self._style["figwidth"] * 1.282736
            mpl_figure.set_size_inches(adj_fig_w, adj_fig_w * base_fig_h / base_fig_w)
            scale = adj_fig_w / base_fig_w

        # otherwise, display default size
        else:
            mpl_figure.set_size_inches(base_fig_w, base_fig_h)

        # drawing will scale with 'set_size_inches', but fonts and linewidths do not
        if scale != 1.0:
            self._style["fs"] *= scale
            self._style["sfs"] *= scale
            self._lwidth1 = 1.0 * scale
            self._lwidth15 = 1.5 * scale
            self._lwidth2 = 2.0 * scale
            self._lwidth3 = 3.0 * scale
            self._lwidth4 = 4.0 * scale

        # Once the scaling factor has been determined, the global phase, register names
        # and numbers, wires, and gates are drawn
        if self._global_phase:
            plt_mod.text(xl, yt, f"Global Phase: {pi_check(self._global_phase, output='mpl')}")
        self._draw_regs_wires(num_folds, xmax, max_x_index, qubits_dict, clbits_dict, glob_data)
        self._draw_ops(
            self._nodes,
            node_data,
            wire_map,
            self._circuit,
            layer_widths,
            qubits_dict,
            clbits_dict,
            glob_data,
            verbose,
        )
        if filename:
            mpl_figure.savefig(
                filename,
                dpi=self._style["dpi"],
                bbox_inches="tight",
                facecolor=mpl_figure.get_facecolor(),
            )
        if not is_user_ax:
            matplotlib_close_if_inline(mpl_figure)
            return mpl_figure

    def _get_layer_widths(self, node_data, wire_map, outer_circuit, glob_data):
        """Compute the layer_widths for the layers"""

        layer_widths = {}
        for layer_num, layer in enumerate(self._nodes):
            widest_box = WID
            for i, node in enumerate(layer):
                # Put the layer_num in the first node in the layer and put -1 in the rest
                # so that layer widths are not counted more than once
                if i != 0:
                    layer_num = -1
                layer_widths[node] = [1, layer_num, self._flow_parent]

                op = node.op
                node_data[node] = NodeData()
                node_data[node].width = WID
                num_ctrl_qubits = getattr(op, "num_ctrl_qubits", 0)
                if (
                    getattr(op, "_directive", False) and (not op.label or not self._plot_barriers)
                ) or isinstance(op, Measure):
                    node_data[node].raw_gate_text = op.name
                    continue

                base_type = getattr(op, "base_gate", None)
                gate_text, ctrl_text, raw_gate_text = get_gate_ctrl_text(
                    op, "mpl", style=self._style
                )
                node_data[node].gate_text = gate_text
                node_data[node].ctrl_text = ctrl_text
                node_data[node].raw_gate_text = raw_gate_text
                node_data[node].param_text = ""

                # if single qubit, no params, and no labels, layer_width is 1
                if (
                    (len(node.qargs) - num_ctrl_qubits) == 1
                    and len(gate_text) < 3
                    and len(getattr(op, "params", [])) == 0
                    and ctrl_text is None
                ):
                    continue

                if isinstance(op, SwapGate) or isinstance(base_type, SwapGate):
                    continue

                # small increments at end of the 3 _get_text_width calls are for small
                # spacing adjustments between gates
                ctrl_width = (
                    self._get_text_width(ctrl_text, glob_data, fontsize=self._style["sfs"]) - 0.05
                )
                # get param_width, but 0 for gates with array params or circuits in params
                if (
                    len(getattr(op, "params", [])) > 0
                    and not any(isinstance(param, np.ndarray) for param in op.params)
                    and not any(isinstance(param, QuantumCircuit) for param in op.params)
                ):
                    param_text = get_param_str(op, "mpl", ndigits=3)
                    if isinstance(op, Initialize):
                        param_text = f"$[{param_text.replace('$', '')}]$"
                    node_data[node].param_text = param_text
                    raw_param_width = self._get_text_width(
                        param_text, glob_data, fontsize=self._style["sfs"], param=True
                    )
                    param_width = raw_param_width + 0.08
                else:
                    param_width = raw_param_width = 0.0

                # get gate_width for sidetext symmetric gates
                if isinstance(op, RZZGate) or isinstance(base_type, (U1Gate, PhaseGate, RZZGate)):
                    if isinstance(base_type, PhaseGate):
                        gate_text = "P"
                    raw_gate_width = (
                        self._get_text_width(
                            gate_text + " ()", glob_data, fontsize=self._style["sfs"]
                        )
                        + raw_param_width
                    )
                    gate_width = (raw_gate_width + 0.08) * 1.58

                # Check if a ControlFlowOp - node_data load for these gates is done here
                elif isinstance(node.op, ControlFlowOp):
                    self._flow_drawers[node] = []
                    node_data[node].width = []
                    node_data[node].nest_depth = 0
                    gate_width = 0.0
                    expr_width = 0.0

                    if (isinstance(op, SwitchCaseOp) and isinstance(op.target, expr.Expr)) or (
                        getattr(op, "condition", None) and isinstance(op.condition, expr.Expr)
                    ):

                        def lookup_var(var):
                            """Look up a classical-expression variable or register/bit in our
                            internal symbol table, and return an OQ3-like identifier."""
                            # We don't attempt to disambiguate anything like register/var naming
                            # collisions; we already don't really show classical variables.
                            if isinstance(var, expr.Var):
                                return ast.Identifier(var.name)
                            if isinstance(var, ClassicalRegister):
                                return ast.Identifier(var.name)
                            # Single clbit.  This is not actually the correct way to lookup a bit on
                            # the circuit (it doesn't handle bit bindings fully), but the mpl
                            # drawer doesn't completely track inner-outer _bit_ bindings, only
                            # inner-indices, so we can't fully recover the information losslessly.
                            # Since most control-flow uses the control-flow builders, we should
                            # decay to something usable most of the time.
                            try:
                                register, bit_index, reg_index = get_bit_reg_index(
                                    outer_circuit, var
                                )
                            except CircuitError:
                                # We failed to find the bit due to binding problems - fall back to
                                # something that's probably wrong, but at least disambiguating.
                                return ast.Identifier(f"bit{wire_map[var]}")
                            if register is None:
                                return ast.Identifier(f"bit{bit_index}")
                            return ast.SubscriptedIdentifier(
                                register.name, ast.IntegerLiteral(reg_index)
                            )

                        condition = op.target if isinstance(op, SwitchCaseOp) else op.condition
                        stream = StringIO()
                        BasicPrinter(stream, indent="  ").visit(
                            condition.accept(_ExprBuilder(lookup_var))
                        )
                        expr_text = stream.getvalue()
                        # Truncate expr_text so that first gate is no more than about 3 x_index's over
                        if len(expr_text) > self._expr_len:
                            expr_text = expr_text[: self._expr_len] + "..."
                        node_data[node].expr_text = expr_text

                        expr_width = self._get_text_width(
                            node_data[node].expr_text, glob_data, fontsize=self._style["sfs"]
                        )
                        node_data[node].expr_width = int(expr_width)

                    # Get the list of circuits to iterate over from the blocks
                    circuit_list = list(node.op.blocks)

                    # params is [indexset, loop_param, circuit] for for_loop,
                    # op.cases_specifier() returns jump tuple and circuit for switch/case
                    if isinstance(op, ForLoopOp):
                        node_data[node].indexset = op.params[0]
                    elif isinstance(op, SwitchCaseOp):
                        node_data[node].jump_values = []
                        cases = list(op.cases_specifier())

                        # Create an empty circuit at the head of the circuit_list if a Switch box
                        circuit_list.insert(0, cases[0][1].copy_empty_like())
                        for jump_values, _ in cases:
                            node_data[node].jump_values.append(jump_values)

                    # Now process the circuits inside the ControlFlowOps
                    for circ_num, circuit in enumerate(circuit_list):
                        # Only add expr_width for if, while, and switch
                        raw_gate_width = expr_width if circ_num == 0 else 0.0

                        # Depth of nested ControlFlowOp used for color of box
                        if self._flow_parent is not None:
                            node_data[node].nest_depth = node_data[self._flow_parent].nest_depth + 1

                        # Build the wire_map to be used by this flow op
                        flow_wire_map = wire_map.copy()
                        flow_wire_map.update(
                            {
                                inner: wire_map[outer]
                                for outer, inner in zip(node.qargs, circuit.qubits)
                            }
                        )
                        for outer, inner in zip(node.cargs, circuit.clbits):
                            if self._cregbundle and (
                                (in_reg := get_bit_register(outer_circuit, inner)) is not None
                            ):
                                out_reg = get_bit_register(outer_circuit, outer)
                                flow_wire_map.update({in_reg: wire_map[out_reg]})
                            else:
                                flow_wire_map.update({inner: wire_map[outer]})

                        # Get the layered node lists and instantiate a new drawer class for
                        # the circuit inside the ControlFlowOp.
                        qubits, clbits, flow_nodes = _get_layered_instructions(
                            circuit, wire_map=flow_wire_map
                        )
                        flow_drawer = MatplotlibDrawer(
                            qubits,
                            clbits,
                            flow_nodes,
                            circuit,
                            style=self._style,
                            plot_barriers=self._plot_barriers,
                            fold=self._fold,
                            cregbundle=self._cregbundle,
                        )

                        # flow_parent is the parent of the new class instance
                        flow_drawer._flow_parent = node
                        flow_drawer._flow_wire_map = flow_wire_map
                        self._flow_drawers[node].append(flow_drawer)

                        # Recursively call _get_layer_widths for the circuit inside the ControlFlowOp
                        flow_widths = flow_drawer._get_layer_widths(
                            node_data, flow_wire_map, outer_circuit, glob_data
                        )
                        layer_widths.update(flow_widths)

                        for flow_layer in flow_nodes:
                            for flow_node in flow_layer:
                                node_data[flow_node].circ_num = circ_num

                        # Add up the width values of the same flow_parent that are not -1
                        # to get the raw_gate_width
                        for width, layer_num, flow_parent in flow_widths.values():
                            if layer_num != -1 and flow_parent == flow_drawer._flow_parent:
                                raw_gate_width += width

                        # Need extra incr of 1.0 for else and case boxes
                        gate_width += raw_gate_width + (1.0 if circ_num > 0 else 0.0)

                        # Minor adjustment so else and case section gates align with indexes
                        if circ_num > 0:
                            raw_gate_width += 0.045

                        # If expr_width has a value, remove the decimal portion from raw_gate_widthl
                        if not isinstance(op, ForLoopOp) and circ_num == 0:
                            node_data[node].width.append(raw_gate_width - (expr_width % 1))
                        else:
                            node_data[node].width.append(raw_gate_width)

                # Otherwise, standard gate or multiqubit gate
                else:
                    raw_gate_width = self._get_text_width(
                        gate_text, glob_data, fontsize=self._style["fs"]
                    )
                    gate_width = raw_gate_width + 0.10
                    # add .21 for the qubit numbers on the left of the multibit gates
                    if len(node.qargs) - num_ctrl_qubits > 1:
                        gate_width += 0.21

                box_width = max(gate_width, ctrl_width, param_width, WID)
                if box_width > widest_box:
                    widest_box = box_width
                if not isinstance(node.op, ControlFlowOp):
                    node_data[node].width = max(raw_gate_width, raw_param_width)
            for node in layer:
                layer_widths[node][0] = int(widest_box) + 1

        return layer_widths

    def _set_bit_reg_info(self, wire_map, qubits_dict, clbits_dict, glob_data):
        """Get all the info for drawing bit/reg names and numbers"""

        longest_wire_label_width = 0
        glob_data["n_lines"] = 0
        initial_qbit = r" $|0\rangle$" if self._initial_state else ""
        initial_cbit = " 0" if self._initial_state else ""

        idx = 0
        pos = y_off = -len(self._qubits) + 1
        for ii, wire in enumerate(wire_map):
            # if it's a creg, register is the key and just load the index
            if isinstance(wire, ClassicalRegister):
                # If wire came from ControlFlowOp and not in clbits, don't draw it
                if wire[0] not in self._clbits:
                    continue
                register = wire
                index = wire_map[wire]

            # otherwise, get the register from find_bit and use bit_index if
            # it's a bit, or the index of the bit in the register if it's a reg
            else:
                # If wire came from ControlFlowOp and not in qubits or clbits, don't draw it
                if wire not in self._qubits + self._clbits:
                    continue
                register, bit_index, reg_index = get_bit_reg_index(self._circuit, wire)
                index = bit_index if register is None else reg_index

            wire_label = get_wire_label(
                "mpl", register, index, layout=self._layout, cregbundle=self._cregbundle
            )
            initial_bit = initial_qbit if isinstance(wire, Qubit) else initial_cbit

            # for cregs with cregbundle on, don't use math formatting, which means
            # no italics
            if isinstance(wire, Qubit) or register is None or not self._cregbundle:
                wire_label = "$" + wire_label + "$"
            wire_label += initial_bit

            reg_size = (
                0 if register is None or isinstance(wire, ClassicalRegister) else register.size
            )
            reg_remove_under = 0 if reg_size < 2 else 1
            text_width = (
                self._get_text_width(
                    wire_label, glob_data, self._style["fs"], reg_remove_under=reg_remove_under
                )
                * 1.15
            )
            if text_width > longest_wire_label_width:
                longest_wire_label_width = text_width

            if isinstance(wire, Qubit):
                pos = -ii
                qubits_dict[ii] = {
                    "y": pos,
                    "wire_label": wire_label,
                }
                glob_data["n_lines"] += 1
            else:
                if (
                    not self._cregbundle
                    or register is None
                    or (self._cregbundle and isinstance(wire, ClassicalRegister))
                ):
                    glob_data["n_lines"] += 1
                    idx += 1

                pos = y_off - idx
                clbits_dict[ii] = {
                    "y": pos,
                    "wire_label": wire_label,
                    "register": register,
                }
        glob_data["x_offset"] = -1.2 + longest_wire_label_width

    def _get_coords(
        self,
        node_data,
        wire_map,
        outer_circuit,
        layer_widths,
        qubits_dict,
        clbits_dict,
        glob_data,
        flow_parent=None,
    ):
        """Load all the coordinate info needed to place the gates on the drawing."""

        prev_x_index = -1
        for layer in self._nodes:
            curr_x_index = prev_x_index + 1
            l_width = []
            for node in layer:
                # For gates inside a flow op set the x_index and if it's an else or case,
                # increment by if/switch width. If more cases increment by width of previous cases.
                if flow_parent is not None:
                    node_data[node].inside_flow = True
                    node_data[node].x_index = node_data[flow_parent].x_index + curr_x_index + 1
                    # If an else or case
                    if node_data[node].circ_num > 0:
                        for width in node_data[flow_parent].width[: node_data[node].circ_num]:
                            node_data[node].x_index += int(width) + 1
                        x_index = node_data[node].x_index
                    # Add expr_width to if, while, or switch if expr used
                    else:
                        x_index = node_data[node].x_index + node_data[flow_parent].expr_width
                else:
                    node_data[node].inside_flow = False
                    x_index = curr_x_index

                # get qubit indexes
                q_indxs = []
                for qarg in node.qargs:
                    if qarg in self._qubits:
                        q_indxs.append(wire_map[qarg])

                # get clbit indexes
                c_indxs = []
                for carg in node.cargs:
                    if carg in self._clbits:
                        if self._cregbundle:
                            register = get_bit_register(outer_circuit, carg)
                            if register is not None:
                                c_indxs.append(wire_map[register])
                            else:
                                c_indxs.append(wire_map[carg])
                        else:
                            c_indxs.append(wire_map[carg])

                flow_op = isinstance(node.op, ControlFlowOp)

                # qubit coordinates
                node_data[node].q_xy = [
                    self._plot_coord(
                        x_index,
                        qubits_dict[ii]["y"],
                        layer_widths[node][0],
                        glob_data,
                        flow_op,
                    )
                    for ii in q_indxs
                ]
                # clbit coordinates
                node_data[node].c_xy = [
                    self._plot_coord(
                        x_index,
                        clbits_dict[ii]["y"],
                        layer_widths[node][0],
                        glob_data,
                        flow_op,
                    )
                    for ii in c_indxs
                ]

                # update index based on the value from plotting
                if flow_parent is None:
                    curr_x_index = glob_data["next_x_index"]
                l_width.append(layer_widths[node][0])
                node_data[node].x_index = x_index

                # Special case of default case with no ops in it, need to push end
                # of switch op one extra x_index
                if isinstance(node.op, SwitchCaseOp):
                    if len(node.op.blocks[-1]) == 0:
                        curr_x_index += 1

            # adjust the column if there have been barriers encountered, but not plotted
            barrier_offset = 0
            if not self._plot_barriers:
                # only adjust if everything in the layer wasn't plotted
                barrier_offset = (
                    -1 if all(getattr(nd.op, "_directive", False) for nd in layer) else 0
                )
            max_lwidth = max(l_width) if l_width else 0
            prev_x_index = curr_x_index + max_lwidth + barrier_offset - 1

        return prev_x_index + 1

    def _get_text_width(self, text, glob_data, fontsize, param=False, reg_remove_under=None):
        """Compute the width of a string in the default font"""

        from pylatexenc.latex2text import LatexNodes2Text

        if not text:
            return 0.0

        math_mode_match = self._mathmode_regex.search(text)
        num_underscores = 0
        num_carets = 0
        if math_mode_match:
            math_mode_text = math_mode_match.group(1)
            num_underscores = math_mode_text.count("_")
            num_carets = math_mode_text.count("^")
        text = LatexNodes2Text().latex_to_text(text.replace("$$", ""))

        # If there are subscripts or superscripts in mathtext string
        # we need to account for that spacing by manually removing
        # from text string for text length

        # if it's a register and there's a subscript at the end,
        # remove 1 underscore, otherwise don't remove any
        if reg_remove_under is not None:
            num_underscores = reg_remove_under
        if num_underscores:
            text = text.replace("_", "", num_underscores)
        if num_carets:
            text = text.replace("^", "", num_carets)

        # This changes hyphen to + to match width of math mode minus sign.
        if param:
            text = text.replace("-", "+")

        f = 0 if fontsize == self._style["fs"] else 1
        sum_text = 0.0
        for c in text:
            try:
                sum_text += self._char_list[c][f]
            except KeyError:
                # if non-ASCII char, use width of 'c', an average size
                sum_text += self._char_list["c"][f]
        if f == 1:
            sum_text *= glob_data["subfont_factor"]
        return sum_text

    def _draw_regs_wires(self, num_folds, xmax, max_x_index, qubits_dict, clbits_dict, glob_data):
        """Draw the register names and numbers, wires, and vertical lines at the ends"""

        for fold_num in range(num_folds + 1):
            # quantum registers
            for qubit in qubits_dict.values():
                qubit_label = qubit["wire_label"]
                y = qubit["y"] - fold_num * (glob_data["n_lines"] + 1)
                self._ax.text(
                    glob_data["x_offset"] - 0.2,
                    y,
                    qubit_label,
                    ha="right",
                    va="center",
                    fontsize=1.25 * self._style["fs"],
                    color=self._style["tc"],
                    clip_on=True,
                    zorder=PORDER_TEXT,
                )
                # draw the qubit wire
                self._line([glob_data["x_offset"], y], [xmax, y], zorder=PORDER_REGLINE)

            # classical registers
            this_clbit_dict = {}
            for clbit in clbits_dict.values():
                y = clbit["y"] - fold_num * (glob_data["n_lines"] + 1)
                if y not in this_clbit_dict:
                    this_clbit_dict[y] = {
                        "val": 1,
                        "wire_label": clbit["wire_label"],
                        "register": clbit["register"],
                    }
                else:
                    this_clbit_dict[y]["val"] += 1

            for y, this_clbit in this_clbit_dict.items():
                # cregbundle
                if self._cregbundle and this_clbit["register"] is not None:
                    self._ax.plot(
                        [glob_data["x_offset"] + 0.2, glob_data["x_offset"] + 0.3],
                        [y - 0.1, y + 0.1],
                        color=self._style["cc"],
                        zorder=PORDER_REGLINE,
                    )
                    self._ax.text(
                        glob_data["x_offset"] + 0.1,
                        y + 0.1,
                        str(this_clbit["register"].size),
                        ha="left",
                        va="bottom",
                        fontsize=0.8 * self._style["fs"],
                        color=self._style["tc"],
                        clip_on=True,
                        zorder=PORDER_TEXT,
                    )
                self._ax.text(
                    glob_data["x_offset"] - 0.2,
                    y,
                    this_clbit["wire_label"],
                    ha="right",
                    va="center",
                    fontsize=1.25 * self._style["fs"],
                    color=self._style["tc"],
                    clip_on=True,
                    zorder=PORDER_TEXT,
                )
                # draw the clbit wire
                self._line(
                    [glob_data["x_offset"], y],
                    [xmax, y],
                    lc=self._style["cc"],
                    ls=self._style["cline"],
                    zorder=PORDER_REGLINE,
                )

            # lf vertical line at either end
            feedline_r = num_folds > 0 and num_folds > fold_num
            feedline_l = fold_num > 0
            if feedline_l or feedline_r:
                xpos_l = glob_data["x_offset"] - 0.01
                xpos_r = self._fold + glob_data["x_offset"] + 0.1
                ypos1 = -fold_num * (glob_data["n_lines"] + 1)
                ypos2 = -(fold_num + 1) * (glob_data["n_lines"]) - fold_num + 1
                if feedline_l:
                    self._ax.plot(
                        [xpos_l, xpos_l],
                        [ypos1, ypos2],
                        color=self._style["lc"],
                        linewidth=self._lwidth15,
                        zorder=PORDER_REGLINE,
                    )
                if feedline_r:
                    self._ax.plot(
                        [xpos_r, xpos_r],
                        [ypos1, ypos2],
                        color=self._style["lc"],
                        linewidth=self._lwidth15,
                        zorder=PORDER_REGLINE,
                    )
            # Mask off any lines or boxes in the bit label area to clean up
            # from folding for ControlFlow and other wrapping gates
            box = glob_data["patches_mod"].Rectangle(
                xy=(glob_data["x_offset"] - 0.1, -fold_num * (glob_data["n_lines"] + 1) + 0.5),
                width=-25.0,
                height=-(fold_num + 1) * (glob_data["n_lines"] + 1),
                fc=self._style["bg"],
                ec=self._style["bg"],
                linewidth=self._lwidth15,
                zorder=PORDER_MASK,
            )
            self._ax.add_patch(box)

        # draw index number
        if self._style["index"]:
            for layer_num in range(max_x_index):
                if self._fold > 0:
                    x_coord = layer_num % self._fold + glob_data["x_offset"] + 0.53
                    y_coord = -(layer_num // self._fold) * (glob_data["n_lines"] + 1) + 0.65
                else:
                    x_coord = layer_num + glob_data["x_offset"] + 0.53
                    y_coord = 0.65
                self._ax.text(
                    x_coord,
                    y_coord,
                    str(layer_num + 1),
                    ha="center",
                    va="center",
                    fontsize=self._style["sfs"],
                    color=self._style["tc"],
                    clip_on=True,
                    zorder=PORDER_TEXT,
                )

    def _add_nodes_and_coords(
        self,
        nodes,
        node_data,
        wire_map,
        outer_circuit,
        layer_widths,
        qubits_dict,
        clbits_dict,
        glob_data,
    ):
        """Add the nodes from ControlFlowOps and their coordinates to the main circuit"""
        for flow_drawers in self._flow_drawers.values():
            for flow_drawer in flow_drawers:
                nodes += flow_drawer._nodes
                flow_drawer._get_coords(
                    node_data,
                    flow_drawer._flow_wire_map,
                    outer_circuit,
                    layer_widths,
                    qubits_dict,
                    clbits_dict,
                    glob_data,
                    flow_parent=flow_drawer._flow_parent,
                )
                # Recurse for ControlFlowOps inside the flow_drawer
                flow_drawer._add_nodes_and_coords(
                    nodes,
                    node_data,
                    wire_map,
                    outer_circuit,
                    layer_widths,
                    qubits_dict,
                    clbits_dict,
                    glob_data,
                )

    def _draw_ops(
        self,
        nodes,
        node_data,
        wire_map,
        outer_circuit,
        layer_widths,
        qubits_dict,
        clbits_dict,
        glob_data,
        verbose=False,
    ):
        """Draw the gates in the circuit"""

        # Add the nodes from all the ControlFlowOps and their coordinates to the main nodes
        self._add_nodes_and_coords(
            nodes,
            node_data,
            wire_map,
            outer_circuit,
            layer_widths,
            qubits_dict,
            clbits_dict,
            glob_data,
        )
        prev_x_index = -1
        for layer in nodes:
            l_width = []
            curr_x_index = prev_x_index + 1

            # draw the gates in this layer
            for node in layer:
                op = node.op

                self._get_colors(node, node_data)

                if verbose:
                    print(op)  # pylint: disable=bad-builtin

                # add conditional
                if getattr(op, "condition", None) or isinstance(op, SwitchCaseOp):
                    cond_xy = [
                        self._plot_coord(
                            node_data[node].x_index,
                            clbits_dict[ii]["y"],
                            layer_widths[node][0],
                            glob_data,
                            isinstance(op, ControlFlowOp),
                        )
                        for ii in clbits_dict
                    ]
                    self._condition(node, node_data, wire_map, outer_circuit, cond_xy, glob_data)

                # AnnotatedOperation with ControlModifier
                mod_control = None
                if getattr(op, "modifiers", None):
                    canonical_modifiers = _canonicalize_modifiers(op.modifiers)
                    for modifier in canonical_modifiers:
                        if isinstance(modifier, ControlModifier):
                            mod_control = modifier
                            break

                # draw measure
                if isinstance(op, Measure):
                    self._measure(node, node_data, outer_circuit, glob_data)

                # draw barriers, snapshots, etc.
                elif getattr(op, "_directive", False):
                    if self._plot_barriers:
                        self._barrier(node, node_data, glob_data)

                # draw the box for control flow circuits
                elif isinstance(op, ControlFlowOp):
                    self._flow_op_gate(node, node_data, glob_data)

                # draw single qubit gates
                elif len(node_data[node].q_xy) == 1 and not node.cargs:
                    self._gate(node, node_data, glob_data)

                # draw controlled gates
                elif isinstance(op, ControlledGate) or mod_control:
                    self._control_gate(node, node_data, glob_data, mod_control)

                # draw multi-qubit gate as final default
                else:
                    self._multiqubit_gate(node, node_data, glob_data)

                # Determine the max width of the circuit only at the top level
                if not node_data[node].inside_flow:
                    l_width.append(layer_widths[node][0])

            # adjust the column if there have been barriers encountered, but not plotted
            barrier_offset = 0
            if not self._plot_barriers:
                # only adjust if everything in the layer wasn't plotted
                barrier_offset = (
                    -1 if all(getattr(nd.op, "_directive", False) for nd in layer) else 0
                )
            prev_x_index = curr_x_index + (max(l_width) if l_width else 0) + barrier_offset - 1

    def _get_colors(self, node, node_data):
        """Get all the colors needed for drawing the circuit"""

        op = node.op
        base_name = getattr(getattr(op, "base_gate", None), "name", None)
        color = None
        if node_data[node].raw_gate_text in self._style["dispcol"]:
            color = self._style["dispcol"][node_data[node].raw_gate_text]
        elif op.name in self._style["dispcol"]:
            color = self._style["dispcol"][op.name]
        if color is not None:
            # Backward compatibility for style dict using 'displaycolor' with
            # gate color and no text color, so test for str first
            if isinstance(color, str):
                fc = color
                gt = self._style["gt"]
            else:
                fc = color[0]
                gt = color[1]
        # Treat special case of classical gates in iqx style by making all
        # controlled gates of x, dcx, and swap the classical gate color
        elif self._style["name"] in ["iqp", "iqx", "iqp-dark", "iqx-dark"] and base_name in [
            "x",
            "dcx",
            "swap",
        ]:
            color = self._style["dispcol"][base_name]
            if isinstance(color, str):
                fc = color
                gt = self._style["gt"]
            else:
                fc = color[0]
                gt = color[1]
        else:
            fc = self._style["gc"]
            gt = self._style["gt"]

        if self._style["name"] == "bw":
            ec = self._style["ec"]
            lc = self._style["lc"]
        else:
            ec = fc
            lc = fc
        # Subtext needs to be same color as gate text
        sc = gt
        node_data[node].fc = fc
        node_data[node].ec = ec
        node_data[node].gt = gt
        node_data[node].tc = self._style["tc"]
        node_data[node].sc = sc
        node_data[node].lc = lc

    def _condition(self, node, node_data, wire_map, outer_circuit, cond_xy, glob_data):
        """Add a conditional to a gate"""

        # For SwitchCaseOp convert the target to a fully closed Clbit or register
        # in condition format
        if isinstance(node.op, SwitchCaseOp):
            if isinstance(node.op.target, expr.Expr):
                condition = node.op.target
            elif isinstance(node.op.target, Clbit):
                condition = (node.op.target, 1)
            else:
                condition = (node.op.target, 2 ** (node.op.target.size) - 1)
        else:
            condition = node.op.condition

        override_fc = False
        first_clbit = len(self._qubits)
        cond_pos = []

        if isinstance(condition, expr.Expr):
            # If fixing this, please update the docstrings of `QuantumCircuit.draw` and
            # `visualization.circuit_drawer` to remove warnings.

            condition_bits = condition_resources(condition).clbits
            label = "[expr]"
            override_fc = True
            registers = collections.defaultdict(list)
            for bit in condition_bits:
                registers[get_bit_register(outer_circuit, bit)].append(bit)
            # Registerless bits don't care whether cregbundle is set.
            cond_pos.extend(cond_xy[wire_map[bit] - first_clbit] for bit in registers.pop(None, ()))
            if self._cregbundle:
                cond_pos.extend(cond_xy[wire_map[register] - first_clbit] for register in registers)
            else:
                cond_pos.extend(
                    cond_xy[wire_map[bit] - first_clbit]
                    for bit in itertools.chain.from_iterable(registers.values())
                )
            val_bits = ["1"] * len(cond_pos)
        else:
            label, val_bits = get_condition_label_val(condition, self._circuit, self._cregbundle)
            cond_bit_reg = condition[0]
            cond_bit_val = int(condition[1])
            override_fc = (
                cond_bit_val != 0
                and self._cregbundle
                and isinstance(cond_bit_reg, ClassicalRegister)
            )

            # In the first case, multiple bits are indicated on the drawing. In all
            # other cases, only one bit is shown.
            if not self._cregbundle and isinstance(cond_bit_reg, ClassicalRegister):
                for idx in range(cond_bit_reg.size):
                    cond_pos.append(cond_xy[wire_map[cond_bit_reg[idx]] - first_clbit])

            # If it's a register bit and cregbundle, need to use the register to find the location
            elif self._cregbundle and isinstance(cond_bit_reg, Clbit):
                register = get_bit_register(outer_circuit, cond_bit_reg)
                if register is not None:
                    cond_pos.append(cond_xy[wire_map[register] - first_clbit])
                else:
                    cond_pos.append(cond_xy[wire_map[cond_bit_reg] - first_clbit])
            else:
                cond_pos.append(cond_xy[wire_map[cond_bit_reg] - first_clbit])

        xy_plot = []
        for val_bit, xy in zip(val_bits, cond_pos):
            fc = self._style["lc"] if override_fc or val_bit == "1" else self._style["bg"]
            box = glob_data["patches_mod"].Circle(
                xy=xy,
                radius=WID * 0.15,
                fc=fc,
                ec=self._style["lc"],
                linewidth=self._lwidth15,
                zorder=PORDER_GATE,
            )
            self._ax.add_patch(box)
            xy_plot.append(xy)

        if not xy_plot:
            # Expression that's only on new-style `expr.Var` nodes, and doesn't need any vertical
            # line drawing.
            return

        qubit_b = min(node_data[node].q_xy, key=lambda xy: xy[1])
        clbit_b = min(xy_plot, key=lambda xy: xy[1])

        # For IfElseOp, WhileLoopOp or SwitchCaseOp, place the condition line
        # near the left edge of the box
        if isinstance(node.op, (IfElseOp, WhileLoopOp, SwitchCaseOp)):
            qubit_b = (qubit_b[0], qubit_b[1] - (0.5 * HIG + 0.14))

        # display the label at the bottom of the lowest conditional and draw the double line
        xpos, ypos = clbit_b
        if isinstance(node.op, Measure):
            xpos += 0.3
        self._ax.text(
            xpos,
            ypos - 0.3 * HIG,
            label,
            ha="center",
            va="top",
            fontsize=self._style["sfs"],
            color=self._style["tc"],
            clip_on=True,
            zorder=PORDER_TEXT,
        )
        self._line(qubit_b, clbit_b, lc=self._style["cc"], ls=self._style["cline"])

    def _measure(self, node, node_data, outer_circuit, glob_data):
        """Draw the measure symbol and the line to the clbit"""
        qx, qy = node_data[node].q_xy[0]
        cx, cy = node_data[node].c_xy[0]
        register, _, reg_index = get_bit_reg_index(outer_circuit, node.cargs[0])

        # draw gate box
        self._gate(node, node_data, glob_data)

        # add measure symbol
        arc = glob_data["patches_mod"].Arc(
            xy=(qx, qy - 0.15 * HIG),
            width=WID * 0.7,
            height=HIG * 0.7,
            theta1=0,
            theta2=180,
            fill=False,
            ec=node_data[node].gt,
            linewidth=self._lwidth2,
            zorder=PORDER_GATE,
        )
        self._ax.add_patch(arc)
        self._ax.plot(
            [qx, qx + 0.35 * WID],
            [qy - 0.15 * HIG, qy + 0.20 * HIG],
            color=node_data[node].gt,
            linewidth=self._lwidth2,
            zorder=PORDER_GATE,
        )
        # arrow
        self._line(
            node_data[node].q_xy[0],
            [cx, cy + 0.35 * WID],
            lc=self._style["cc"],
            ls=self._style["cline"],
        )
        arrowhead = glob_data["patches_mod"].Polygon(
            (
                (cx - 0.20 * WID, cy + 0.35 * WID),
                (cx + 0.20 * WID, cy + 0.35 * WID),
                (cx, cy + 0.04),
            ),
            fc=self._style["cc"],
            ec=None,
        )
        self._ax.add_artist(arrowhead)
        # target
        if self._cregbundle and register is not None:
            self._ax.text(
                cx + 0.25,
                cy + 0.1,
                str(reg_index),
                ha="left",
                va="bottom",
                fontsize=0.8 * self._style["fs"],
                color=self._style["tc"],
                clip_on=True,
                zorder=PORDER_TEXT,
            )

    def _barrier(self, node, node_data, glob_data):
        """Draw a barrier"""
        for i, xy in enumerate(node_data[node].q_xy):
            xpos, ypos = xy
            # For the topmost barrier, reduce the rectangle if there's a label to allow for the text.
            if i == 0 and node.op.label is not None:
                ypos_adj = -0.35
            else:
                ypos_adj = 0.0
            self._ax.plot(
                [xpos, xpos],
                [ypos + 0.5 + ypos_adj, ypos - 0.5],
                linewidth=self._lwidth1,
                linestyle="dashed",
                color=self._style["lc"],
                zorder=PORDER_TEXT,
            )
            box = glob_data["patches_mod"].Rectangle(
                xy=(xpos - (0.3 * WID), ypos - 0.5),
                width=0.6 * WID,
                height=1.0 + ypos_adj,
                fc=self._style["bc"],
                ec=None,
                alpha=0.6,
                linewidth=self._lwidth15,
                zorder=PORDER_BARRIER,
            )
            self._ax.add_patch(box)

            # display the barrier label at the top if there is one
            if i == 0 and node.op.label is not None:
                dir_ypos = ypos + 0.65 * HIG
                self._ax.text(
                    xpos,
                    dir_ypos,
                    node.op.label,
                    ha="center",
                    va="top",
                    fontsize=self._style["fs"],
                    color=node_data[node].tc,
                    clip_on=True,
                    zorder=PORDER_TEXT,
                )

    def _gate(self, node, node_data, glob_data, xy=None):
        """Draw a 1-qubit gate"""
        if xy is None:
            xy = node_data[node].q_xy[0]
        xpos, ypos = xy
        wid = max(node_data[node].width, WID)

        box = glob_data["patches_mod"].Rectangle(
            xy=(xpos - 0.5 * wid, ypos - 0.5 * HIG),
            width=wid,
            height=HIG,
            fc=node_data[node].fc,
            ec=node_data[node].ec,
            linewidth=self._lwidth15,
            zorder=PORDER_GATE,
        )
        self._ax.add_patch(box)

        if node_data[node].gate_text:
            gate_ypos = ypos
            if node_data[node].param_text:
                gate_ypos = ypos + 0.15 * HIG
                self._ax.text(
                    xpos,
                    ypos - 0.3 * HIG,
                    node_data[node].param_text,
                    ha="center",
                    va="center",
                    fontsize=self._style["sfs"],
                    color=node_data[node].sc,
                    clip_on=True,
                    zorder=PORDER_TEXT,
                )
            self._ax.text(
                xpos,
                gate_ypos,
                node_data[node].gate_text,
                ha="center",
                va="center",
                fontsize=self._style["fs"],
                color=node_data[node].gt,
                clip_on=True,
                zorder=PORDER_TEXT,
            )

    def _multiqubit_gate(self, node, node_data, glob_data, xy=None):
        """Draw a gate covering more than one qubit"""
        op = node.op
        if xy is None:
            xy = node_data[node].q_xy

        # Swap gate
        if isinstance(op, SwapGate):
            self._swap(xy, node_data[node].lc)
            return

        # RZZ Gate
        elif isinstance(op, RZZGate):
            self._symmetric_gate(node, node_data, RZZGate, glob_data)
            return

        c_xy = node_data[node].c_xy
        xpos = min(x[0] for x in xy)
        ypos = min(y[1] for y in xy)
        ypos_max = max(y[1] for y in xy)
        if c_xy:
            cxpos = min(x[0] for x in c_xy)
            cypos = min(y[1] for y in c_xy)
            ypos = min(ypos, cypos)

        wid = max(node_data[node].width + 0.21, WID)
        qubit_span = abs(ypos) - abs(ypos_max)
        height = HIG + qubit_span

        box = glob_data["patches_mod"].Rectangle(
            xy=(xpos - 0.5 * wid, ypos - 0.5 * HIG),
            width=wid,
            height=height,
            fc=node_data[node].fc,
            ec=node_data[node].ec,
            linewidth=self._lwidth15,
            zorder=PORDER_GATE,
        )
        self._ax.add_patch(box)

        # annotate inputs
        for bit, y in enumerate([x[1] for x in xy]):
            self._ax.text(
                xpos + 0.07 - 0.5 * wid,
                y,
                str(bit),
                ha="left",
                va="center",
                fontsize=self._style["fs"],
                color=node_data[node].gt,
                clip_on=True,
                zorder=PORDER_TEXT,
            )
        if c_xy:
            # annotate classical inputs
            for bit, y in enumerate([x[1] for x in c_xy]):
                self._ax.text(
                    cxpos + 0.07 - 0.5 * wid,
                    y,
                    str(bit),
                    ha="left",
                    va="center",
                    fontsize=self._style["fs"],
                    color=node_data[node].gt,
                    clip_on=True,
                    zorder=PORDER_TEXT,
                )
        if node_data[node].gate_text:
            gate_ypos = ypos + 0.5 * qubit_span
            if node_data[node].param_text:
                gate_ypos = ypos + 0.4 * height
                self._ax.text(
                    xpos + 0.11,
                    ypos + 0.2 * height,
                    node_data[node].param_text,
                    ha="center",
                    va="center",
                    fontsize=self._style["sfs"],
                    color=node_data[node].sc,
                    clip_on=True,
                    zorder=PORDER_TEXT,
                )
            self._ax.text(
                xpos + 0.11,
                gate_ypos,
                node_data[node].gate_text,
                ha="center",
                va="center",
                fontsize=self._style["fs"],
                color=node_data[node].gt,
                clip_on=True,
                zorder=PORDER_TEXT,
            )

    def _flow_op_gate(self, node, node_data, glob_data):
        """Draw the box for a flow op circuit"""
        xy = node_data[node].q_xy
        xpos = min(x[0] for x in xy)
        ypos = min(y[1] for y in xy)
        ypos_max = max(y[1] for y in xy)

        if_width = node_data[node].width[0] + WID
        box_width = if_width
        # Add the else and case widths to the if_width
        for ewidth in node_data[node].width[1:]:
            if ewidth > 0.0:
                box_width += ewidth + WID + 0.3

        qubit_span = abs(ypos) - abs(ypos_max)
        height = HIG + qubit_span

        # Cycle through box colors based on depth.
        # Default - blue, purple, green, black
        colors = [
            self._style["dispcol"]["h"][0],
            self._style["dispcol"]["u"][0],
            self._style["dispcol"]["x"][0],
            self._style["cc"],
        ]
        # To fold box onto next lines, draw it repeatedly, shifting
        # it left by x_shift and down by y_shift
        fold_level = 0
        end_x = xpos + box_width

        while end_x > 0.0:
            x_shift = fold_level * self._fold
            y_shift = fold_level * (glob_data["n_lines"] + 1)
            end_x = xpos + box_width - x_shift if self._fold > 0 else 0.0

            if isinstance(node.op, IfElseOp):
                flow_text = "  If"
            elif isinstance(node.op, WhileLoopOp):
                flow_text = " While"
            elif isinstance(node.op, ForLoopOp):
                flow_text = " For"
            elif isinstance(node.op, SwitchCaseOp):
                flow_text = "Switch"
            elif isinstance(node.op, BoxOp):
                flow_text = ""
            else:
                raise RuntimeError(f"unhandled control-flow op: {node.name}")

            # Some spacers. op_spacer moves 'Switch' back a bit for alignment,
            # expr_spacer moves the expr over to line up with 'Switch' and
            # empty_default_spacer makes the switch box longer if the default
            # case is empty so text doesn't run past end of box.
            if isinstance(node.op, SwitchCaseOp):
                op_spacer = 0.04
                expr_spacer = 0.0
                empty_default_spacer = 0.3 if len(node.op.blocks[-1]) == 0 else 0.0
            elif isinstance(node.op, BoxOp):
                op_spacer = 0.0
                expr_spacer = 0.0
                empty_default_spacer = 0.0
            else:
                op_spacer = 0.08
                expr_spacer = 0.02
                empty_default_spacer = 0.0

            # FancyBbox allows rounded corners
            box = glob_data["patches_mod"].FancyBboxPatch(
                xy=(xpos - x_shift, ypos - 0.5 * HIG - y_shift),
                width=box_width + empty_default_spacer,
                height=height,
                boxstyle="round, pad=0.1",
                fc="none",
                ec=colors[node_data[node].nest_depth % 4],
                linewidth=self._lwidth3,
                zorder=PORDER_FLOW,
            )
            self._ax.add_patch(box)

            # Indicate type of ControlFlowOp and if expression used, print below
            self._ax.text(
                xpos - x_shift - op_spacer,
                ypos_max + 0.2 - y_shift,
                flow_text,
                ha="left",
                va="center",
                fontsize=self._style["fs"],
                color=node_data[node].tc,
                clip_on=True,
                zorder=PORDER_FLOW,
            )
            self._ax.text(
                xpos - x_shift + expr_spacer,
                ypos_max + 0.2 - y_shift - 0.4,
                node_data[node].expr_text,
                ha="left",
                va="center",
                fontsize=self._style["sfs"],
                color=node_data[node].tc,
                clip_on=True,
                zorder=PORDER_FLOW,
            )
            if isinstance(node.op, ForLoopOp):
                idx_set = str(node_data[node].indexset)
                # If a range was used display 'range' and grab the range value
                # to be displayed below
                if "range" in idx_set:
                    idx_set = "r(" + idx_set[6:-1] + ")"
                else:
                    # If a tuple, show first 4 elements followed by '...'
                    idx_set = str(node_data[node].indexset)[1:-1].split(",")[:5]
                    if len(idx_set) > 4:
                        idx_set[4] = "..."
                    idx_set = f"{','.join(idx_set)}"
                y_spacer = 0.2 if len(node.qargs) == 1 else 0.5
                self._ax.text(
                    xpos - x_shift - 0.04,
                    ypos_max - y_spacer - y_shift,
                    idx_set,
                    ha="left",
                    va="center",
                    fontsize=self._style["sfs"],
                    color=node_data[node].tc,
                    clip_on=True,
                    zorder=PORDER_FLOW,
                )
            # If there's an else or a case draw the vertical line and the name
            else_case_text = "Else" if isinstance(node.op, IfElseOp) else "Case"
            ewidth_incr = if_width
            for circ_num, ewidth in enumerate(node_data[node].width[1:]):
                if ewidth > 0.0:
                    self._ax.plot(
                        [xpos + ewidth_incr + 0.3 - x_shift, xpos + ewidth_incr + 0.3 - x_shift],
                        [ypos - 0.5 * HIG - 0.08 - y_shift, ypos + height - 0.22 - y_shift],
                        color=colors[node_data[node].nest_depth % 4],
                        linewidth=3.0,
                        linestyle="solid",
                        zorder=PORDER_FLOW,
                    )
                    self._ax.text(
                        xpos + ewidth_incr + 0.4 - x_shift,
                        ypos_max + 0.2 - y_shift,
                        else_case_text,
                        ha="left",
                        va="center",
                        fontsize=self._style["fs"],
                        color=node_data[node].tc,
                        clip_on=True,
                        zorder=PORDER_FLOW,
                    )
                    if isinstance(node.op, SwitchCaseOp):
                        jump_val = node_data[node].jump_values[circ_num]
                        # If only one value, e.g. (0,)
                        if len(str(jump_val)) == 4:
                            jump_text = str(jump_val)[1]
                        elif "default" in str(jump_val):
                            jump_text = "default"
                        else:
                            # If a tuple, show first 4 elements followed by '...'
                            jump_text = str(jump_val)[1:-1].replace(" ", "").split(",")[:5]
                            if len(jump_text) > 4:
                                jump_text[4] = "..."
                            jump_text = f"{', '.join(jump_text)}"
                        y_spacer = 0.2 if len(node.qargs) == 1 else 0.5
                        self._ax.text(
                            xpos + ewidth_incr + 0.4 - x_shift,
                            ypos_max - y_spacer - y_shift,
                            jump_text,
                            ha="left",
                            va="center",
                            fontsize=self._style["sfs"],
                            color=node_data[node].tc,
                            clip_on=True,
                            zorder=PORDER_FLOW,
                        )
                ewidth_incr += ewidth + 1

            fold_level += 1

    def _control_gate(self, node, node_data, glob_data, mod_control):
        """Draw a controlled gate"""
        op = node.op
        xy = node_data[node].q_xy
        base_type = getattr(op, "base_gate", None)
        qubit_b = min(xy, key=lambda xy: xy[1])
        qubit_t = max(xy, key=lambda xy: xy[1])
        num_ctrl_qubits = mod_control.num_ctrl_qubits if mod_control else op.num_ctrl_qubits
        num_qargs = len(xy) - num_ctrl_qubits
        ctrl_state = mod_control.ctrl_state if mod_control else op.ctrl_state
        self._set_ctrl_bits(
            ctrl_state,
            num_ctrl_qubits,
            xy,
            glob_data,
            ec=node_data[node].ec,
            tc=node_data[node].tc,
            text=node_data[node].ctrl_text,
            qargs=node.qargs,
        )
        self._line(qubit_b, qubit_t, lc=node_data[node].lc)

        if isinstance(op, RZZGate) or isinstance(base_type, (U1Gate, PhaseGate, ZGate, RZZGate)):
            self._symmetric_gate(node, node_data, base_type, glob_data)

        elif num_qargs == 1 and isinstance(base_type, XGate):
            tgt_color = self._style["dispcol"]["target"]
            tgt = tgt_color if isinstance(tgt_color, str) else tgt_color[0]
            self._x_tgt_qubit(xy[num_ctrl_qubits], glob_data, ec=node_data[node].ec, ac=tgt)

        elif num_qargs == 1:
            self._gate(node, node_data, glob_data, xy[num_ctrl_qubits:][0])

        elif isinstance(base_type, SwapGate):
            self._swap(xy[num_ctrl_qubits:], node_data[node].lc)

        else:
            self._multiqubit_gate(node, node_data, glob_data, xy[num_ctrl_qubits:])

    def _set_ctrl_bits(
        self, ctrl_state, num_ctrl_qubits, qbit, glob_data, ec=None, tc=None, text="", qargs=None
    ):
        """Determine which qubits are controls and whether they are open or closed"""
        # place the control label at the top or bottom of controls
        if text:
            qlist = [self._circuit.find_bit(qubit).index for qubit in qargs]
            ctbits = qlist[:num_ctrl_qubits]
            qubits = qlist[num_ctrl_qubits:]
            max_ctbit = max(ctbits)
            min_ctbit = min(ctbits)
            top = min(qubits) > min_ctbit

        # display the control qubits as open or closed based on ctrl_state
        cstate = f"{ctrl_state:b}".rjust(num_ctrl_qubits, "0")[::-1]
        for i in range(num_ctrl_qubits):
            fc_open_close = ec if cstate[i] == "1" else self._style["bg"]
            text_top = None
            if text:
                if top and qlist[i] == min_ctbit:
                    text_top = True
                elif not top and qlist[i] == max_ctbit:
                    text_top = False
            self._ctrl_qubit(
                qbit[i], glob_data, fc=fc_open_close, ec=ec, tc=tc, text=text, text_top=text_top
            )

    def _ctrl_qubit(self, xy, glob_data, fc=None, ec=None, tc=None, text="", text_top=None):
        """Draw a control circle and if top or bottom control, draw control label"""
        xpos, ypos = xy
        box = glob_data["patches_mod"].Circle(
            xy=(xpos, ypos),
            radius=WID * 0.15,
            fc=fc,
            ec=ec,
            linewidth=self._lwidth15,
            zorder=PORDER_GATE,
        )
        self._ax.add_patch(box)

        # adjust label height according to number of lines of text
        label_padding = 0.7
        if text is not None:
            text_lines = text.count("\n")
            if not text.endswith("(cal)\n"):
                for _ in range(text_lines):
                    label_padding += 0.3

        if text_top is None:
            return

        # display the control label at the top or bottom if there is one
        ctrl_ypos = ypos + label_padding * HIG if text_top else ypos - 0.3 * HIG
        self._ax.text(
            xpos,
            ctrl_ypos,
            text,
            ha="center",
            va="top",
            fontsize=self._style["sfs"],
            color=tc,
            clip_on=True,
            zorder=PORDER_TEXT,
        )

    def _x_tgt_qubit(self, xy, glob_data, ec=None, ac=None):
        """Draw the cnot target symbol"""
        linewidth = self._lwidth2
        xpos, ypos = xy
        box = glob_data["patches_mod"].Circle(
            xy=(xpos, ypos),
            radius=HIG * 0.35,
            fc=ec,
            ec=ec,
            linewidth=linewidth,
            zorder=PORDER_GATE,
        )
        self._ax.add_patch(box)

        # add '+' symbol
        self._ax.plot(
            [xpos, xpos],
            [ypos - 0.2 * HIG, ypos + 0.2 * HIG],
            color=ac,
            linewidth=linewidth,
            zorder=PORDER_GATE_PLUS,
        )
        self._ax.plot(
            [xpos - 0.2 * HIG, xpos + 0.2 * HIG],
            [ypos, ypos],
            color=ac,
            linewidth=linewidth,
            zorder=PORDER_GATE_PLUS,
        )

    def _symmetric_gate(self, node, node_data, base_type, glob_data):
        """Draw symmetric gates for cz, cu1, cp, and rzz"""
        op = node.op
        xy = node_data[node].q_xy
        qubit_b = min(xy, key=lambda xy: xy[1])
        qubit_t = max(xy, key=lambda xy: xy[1])
        base_type = getattr(op, "base_gate", None)
        ec = node_data[node].ec
        tc = node_data[node].tc
        lc = node_data[node].lc

        # cz and mcz gates
        if not isinstance(op, ZGate) and isinstance(base_type, ZGate):
            num_ctrl_qubits = op.num_ctrl_qubits
            self._ctrl_qubit(xy[-1], glob_data, fc=ec, ec=ec, tc=tc)
            self._line(qubit_b, qubit_t, lc=lc, zorder=PORDER_LINE_PLUS)

        # cu1, cp, rzz, and controlled rzz gates (sidetext gates)
        elif isinstance(op, RZZGate) or isinstance(base_type, (U1Gate, PhaseGate, RZZGate)):
            num_ctrl_qubits = 0 if isinstance(op, RZZGate) else op.num_ctrl_qubits
            gate_text = "P" if isinstance(base_type, PhaseGate) else node_data[node].gate_text

            self._ctrl_qubit(xy[num_ctrl_qubits], glob_data, fc=ec, ec=ec, tc=tc)
            if not isinstance(base_type, (U1Gate, PhaseGate)):
                self._ctrl_qubit(xy[num_ctrl_qubits + 1], glob_data, fc=ec, ec=ec, tc=tc)

            self._sidetext(
                node,
                node_data,
                qubit_b,
                tc=tc,
                text=f"{gate_text} ({node_data[node].param_text})",
            )
            self._line(qubit_b, qubit_t, lc=lc)

    def _swap(self, xy, color=None):
        """Draw a Swap gate"""
        self._swap_cross(xy[0], color=color)
        self._swap_cross(xy[1], color=color)
        self._line(xy[0], xy[1], lc=color)

    def _swap_cross(self, xy, color=None):
        """Draw the Swap cross symbol"""
        xpos, ypos = xy

        self._ax.plot(
            [xpos - 0.20 * WID, xpos + 0.20 * WID],
            [ypos - 0.20 * WID, ypos + 0.20 * WID],
            color=color,
            linewidth=self._lwidth2,
            zorder=PORDER_LINE_PLUS,
        )
        self._ax.plot(
            [xpos - 0.20 * WID, xpos + 0.20 * WID],
            [ypos + 0.20 * WID, ypos - 0.20 * WID],
            color=color,
            linewidth=self._lwidth2,
            zorder=PORDER_LINE_PLUS,
        )

    def _sidetext(self, node, node_data, xy, tc=None, text=""):
        """Draw the sidetext for symmetric gates"""
        xpos, ypos = xy

        # 0.11 = the initial gap, add 1/2 text width to place on the right
        xp = xpos + 0.11 + node_data[node].width / 2
        self._ax.text(
            xp,
            ypos + HIG,
            text,
            ha="center",
            va="top",
            fontsize=self._style["sfs"],
            color=tc,
            clip_on=True,
            zorder=PORDER_TEXT,
        )

    def _line(self, xy0, xy1, lc=None, ls=None, zorder=PORDER_LINE):
        """Draw a line from xy0 to xy1"""
        x0, y0 = xy0
        x1, y1 = xy1
        linecolor = self._style["lc"] if lc is None else lc
        linestyle = "solid" if ls is None else ls

        if linestyle == "doublet":
            theta = np.arctan2(np.abs(x1 - x0), np.abs(y1 - y0))
            dx = 0.05 * WID * np.cos(theta)
            dy = 0.05 * WID * np.sin(theta)
            self._ax.plot(
                [x0 + dx, x1 + dx],
                [y0 + dy, y1 + dy],
                color=linecolor,
                linewidth=self._lwidth2,
                linestyle="solid",
                zorder=zorder,
            )
            self._ax.plot(
                [x0 - dx, x1 - dx],
                [y0 - dy, y1 - dy],
                color=linecolor,
                linewidth=self._lwidth2,
                linestyle="solid",
                zorder=zorder,
            )
        else:
            self._ax.plot(
                [x0, x1],
                [y0, y1],
                color=linecolor,
                linewidth=self._lwidth2,
                linestyle=linestyle,
                zorder=zorder,
            )

    def _plot_coord(self, x_index, y_index, gate_width, glob_data, flow_op=False):
        """Get the coord positions for an index"""

        # Check folding
        fold = self._fold if self._fold > 0 else INFINITE_FOLD
        h_pos = x_index % fold + 1

        # Don't fold flow_ops here, only gates inside the flow_op
        if not flow_op and h_pos + (gate_width - 1) > fold:
            x_index += fold - (h_pos - 1)
        x_pos = x_index % fold + glob_data["x_offset"] + 0.04
        if not flow_op:
            x_pos += 0.5 * gate_width
        else:
            x_pos += 0.25
        y_pos = y_index - (x_index // fold) * (glob_data["n_lines"] + 1)

        # x_index could have been updated, so need to store
        glob_data["next_x_index"] = x_index
        return x_pos, y_pos


class NodeData:
    """Class containing drawing data on a per node basis"""

    def __init__(self):
        # Node data for positioning
        self.width = 0.0
        self.x_index = 0
        self.q_xy = []
        self.c_xy = []

        # Node data for text
        self.gate_text = ""
        self.raw_gate_text = ""
        self.ctrl_text = ""
        self.param_text = ""

        # Node data for color
        self.fc = self.ec = self.lc = self.sc = self.gt = self.tc = 0

        # Special values stored for ControlFlowOps
        self.nest_depth = 0
        self.expr_width = 0.0
        self.expr_text = ""
        self.inside_flow = False
        self.indexset = ()  # List of indices used for ForLoopOp
        self.jump_values = []  # List of jump values used for SwitchCaseOp
        self.circ_num = 0  # Which block is it in op.blocks

Qiskit / qiskit / 13688561003

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