backend_wx.py

"""
A wxPython backend for matplotlib.

Originally contributed by Jeremy O'Donoghue (jeremy@o-donoghue.com) and John
Hunter (jdhunter@ace.bsd.uchicago.edu).

Copyright (C) Jeremy O'Donoghue & John Hunter, 2003-4.
"""

import logging
import math
import os.path
import sys
import weakref

import matplotlib
from matplotlib.backend_bases import (
    _Backend, FigureCanvasBase, FigureManagerBase, GraphicsContextBase,
    MouseButton, NavigationToolbar2, RendererBase, StatusbarBase, TimerBase,
    ToolContainerBase, _has_pil, cursors)

from matplotlib import cbook, rcParams, backend_tools
from matplotlib._pylab_helpers import Gcf
from matplotlib.backend_managers import ToolManager
from matplotlib.figure import Figure
from matplotlib.path import Path
from matplotlib.transforms import Affine2D
from matplotlib.widgets import SubplotTool

import wx

_log = logging.getLogger(__name__)

# Debugging settings here...
# Debug level set here. If the debug level is less than 5, information
# messages (progressively more info for lower value) are printed. In addition,
# traceback is performed, and pdb activated, for all uncaught exceptions in
# this case
_DEBUG = 5
_DEBUG_lvls = {1: 'Low ', 2: 'Med ', 3: 'High', 4: 'Error'}


def DEBUG_MSG(string, lvl=3, o=None):
    if lvl >= _DEBUG:
        print(f"{_DEBUG_lvls[lvl]}- {string} in {type(o)}")


@cbook.deprecated("3.1")
def debug_on_error(type, value, tb):
    """Code due to Thomas Heller - published in Python Cookbook (O'Reilly)"""
    import pdb
    import traceback
    traceback.print_exception(type, value, tb)
    print()
    pdb.pm()


@cbook.deprecated("3.1")
class fake_stderr:
    """
    Wx does strange things with stderr, as it makes the assumption that
    there is probably no console. This redirects stderr to the console, since
    we know that there is one!
    """

    def write(self, msg):
        print("Stderr: %s\n\r" % msg)


# the True dots per inch on the screen; should be display dependent
# see
# http://groups.google.com/groups?q=screen+dpi+x11&hl=en&lr=&ie=UTF-8&oe=UTF-8&safe=off&selm=7077.26e81ad5%40swift.cs.tcd.ie&rnum=5
# for some info about screen dpi
PIXELS_PER_INCH = 75

# Delay time for idle checks
IDLE_DELAY = 5  # Documented as deprecated as of Matplotlib 3.1.


def error_msg_wx(msg, parent=None):
    """
    Signal an error condition -- in a GUI, popup a error dialog
    """
    dialog = wx.MessageDialog(parent=parent,
                              message=msg,
                              caption='Matplotlib backend_wx error',
                              style=wx.OK | wx.CENTRE)
    dialog.ShowModal()
    dialog.Destroy()
    return None


@cbook.deprecated("3.1")
def raise_msg_to_str(msg):
    """msg is a return arg from a raise.  Join with new lines."""
    if not isinstance(msg, str):
        msg = '\n'.join(map(str, msg))
    return msg


class TimerWx(TimerBase):
    """
    Subclass of `.TimerBase` that uses WxTimer events.

    Attributes
    ----------
    interval : int
        The time between timer events in milliseconds. Default is 1000 ms.
    single_shot : bool
        Boolean flag indicating whether this timer should operate as single
        shot (run once and then stop). Defaults to False.
    callbacks : list
        Stores list of (func, args) tuples that will be called upon timer
        events. This list can be manipulated directly, or the functions
        `add_callback` and `remove_callback` can be used.
    """

    def __init__(self, *args, **kwargs):
        if args and isinstance(args[0], wx.EvtHandler):
            cbook.warn_deprecated(
                "3.0", message="Passing a wx.EvtHandler as first argument to "
                "the TimerWx constructor is deprecated since %(since)s.")
            args = args[1:]
        TimerBase.__init__(self, *args, **kwargs)
        self._timer = wx.Timer()
        self._timer.Notify = self._on_timer

    def _timer_start(self):
        self._timer.Start(self._interval, self._single)

    def _timer_stop(self):
        self._timer.Stop()

    def _timer_set_interval(self):
        self._timer_start()

    def _timer_set_single_shot(self):
        self._timer.Start()


class RendererWx(RendererBase):
    """
    The renderer handles all the drawing primitives using a graphics
    context instance that controls the colors/styles. It acts as the
    'renderer' instance used by many classes in the hierarchy.
    """
    # In wxPython, drawing is performed on a wxDC instance, which will
    # generally be mapped to the client area of the window displaying
    # the plot. Under wxPython, the wxDC instance has a wx.Pen which
    # describes the colour and weight of any lines drawn, and a wxBrush
    # which describes the fill colour of any closed polygon.

    # Font styles, families and weight.
    fontweights = {
        100: wx.FONTWEIGHT_LIGHT,
        200: wx.FONTWEIGHT_LIGHT,
        300: wx.FONTWEIGHT_LIGHT,
        400: wx.FONTWEIGHT_NORMAL,
        500: wx.FONTWEIGHT_NORMAL,
        600: wx.FONTWEIGHT_NORMAL,
        700: wx.FONTWEIGHT_BOLD,
        800: wx.FONTWEIGHT_BOLD,
        900: wx.FONTWEIGHT_BOLD,
        'ultralight': wx.FONTWEIGHT_LIGHT,
        'light': wx.FONTWEIGHT_LIGHT,
        'normal': wx.FONTWEIGHT_NORMAL,
        'medium': wx.FONTWEIGHT_NORMAL,
        'semibold': wx.FONTWEIGHT_NORMAL,
        'bold': wx.FONTWEIGHT_BOLD,
        'heavy': wx.FONTWEIGHT_BOLD,
        'ultrabold': wx.FONTWEIGHT_BOLD,
        'black': wx.FONTWEIGHT_BOLD,
    }
    fontangles = {
        'italic': wx.FONTSTYLE_ITALIC,
        'normal': wx.FONTSTYLE_NORMAL,
        'oblique': wx.FONTSTYLE_SLANT,
    }

    # wxPython allows for portable font styles, choosing them appropriately for
    # the target platform. Map some standard font names to the portable styles.
    # QUESTION: Is it be wise to agree standard fontnames across all backends?
    fontnames = {
        'Sans': wx.FONTFAMILY_SWISS,
        'Roman': wx.FONTFAMILY_ROMAN,
        'Script': wx.FONTFAMILY_SCRIPT,
        'Decorative': wx.FONTFAMILY_DECORATIVE,
        'Modern': wx.FONTFAMILY_MODERN,
        'Courier': wx.FONTFAMILY_MODERN,
        'courier': wx.FONTFAMILY_MODERN,
    }

    def __init__(self, bitmap, dpi):
        """Initialise a wxWindows renderer instance."""
        cbook.warn_deprecated(
            "2.0", name="wx", obj_type="backend", removal="the future",
            alternative="wxagg", addendum="See the Matplotlib usage FAQ for "
            "more info on backends.")
        RendererBase.__init__(self)
        DEBUG_MSG("__init__()", 1, self)
        self.width = bitmap.GetWidth()
        self.height = bitmap.GetHeight()
        self.bitmap = bitmap
        self.fontd = {}
        self.dpi = dpi
        self.gc = None

    def flipy(self):
        # docstring inherited
        return True

    def offset_text_height(self):
        return True

    def get_text_width_height_descent(self, s, prop, ismath):
        # docstring inherited

        if ismath:
            s = cbook.strip_math(s)

        if self.gc is None:
            gc = self.new_gc()
        else:
            gc = self.gc
        gfx_ctx = gc.gfx_ctx
        font = self.get_wx_font(s, prop)
        gfx_ctx.SetFont(font, wx.BLACK)
        w, h, descent, leading = gfx_ctx.GetFullTextExtent(s)

        return w, h, descent

    def get_canvas_width_height(self):
        # docstring inherited
        return self.width, self.height

    def handle_clip_rectangle(self, gc):
        new_bounds = gc.get_clip_rectangle()
        if new_bounds is not None:
            new_bounds = new_bounds.bounds
        gfx_ctx = gc.gfx_ctx
        if gfx_ctx._lastcliprect != new_bounds:
            gfx_ctx._lastcliprect = new_bounds
            if new_bounds is None:
                gfx_ctx.ResetClip()
            else:
                gfx_ctx.Clip(new_bounds[0],
                             self.height - new_bounds[1] - new_bounds[3],
                             new_bounds[2], new_bounds[3])

    @staticmethod
    def convert_path(gfx_ctx, path, transform):
        wxpath = gfx_ctx.CreatePath()
        for points, code in path.iter_segments(transform):
            if code == Path.MOVETO:
                wxpath.MoveToPoint(*points)
            elif code == Path.LINETO:
                wxpath.AddLineToPoint(*points)
            elif code == Path.CURVE3:
                wxpath.AddQuadCurveToPoint(*points)
            elif code == Path.CURVE4:
                wxpath.AddCurveToPoint(*points)
            elif code == Path.CLOSEPOLY:
                wxpath.CloseSubpath()
        return wxpath

    def draw_path(self, gc, path, transform, rgbFace=None):
        # docstring inherited
        gc.select()
        self.handle_clip_rectangle(gc)
        gfx_ctx = gc.gfx_ctx
        transform = transform + \
            Affine2D().scale(1.0, -1.0).translate(0.0, self.height)
        wxpath = self.convert_path(gfx_ctx, path, transform)
        if rgbFace is not None:
            gfx_ctx.SetBrush(wx.Brush(gc.get_wxcolour(rgbFace)))
            gfx_ctx.DrawPath(wxpath)
        else:
            gfx_ctx.StrokePath(wxpath)
        gc.unselect()

    def draw_image(self, gc, x, y, im):
        bbox = gc.get_clip_rectangle()
        if bbox is not None:
            l, b, w, h = bbox.bounds
        else:
            l = 0
            b = 0
            w = self.width
            h = self.height
        rows, cols = im.shape[:2]
        bitmap = wx.Bitmap.FromBufferRGBA(cols, rows, im.tostring())
        gc = self.get_gc()
        gc.select()
        gc.gfx_ctx.DrawBitmap(bitmap, int(l), int(self.height - b),
                              int(w), int(-h))
        gc.unselect()

    def draw_text(self, gc, x, y, s, prop, angle, ismath=False, mtext=None):
        # docstring inherited

        if ismath:
            s = cbook.strip_math(s)
        DEBUG_MSG("draw_text()", 1, self)
        gc.select()
        self.handle_clip_rectangle(gc)
        gfx_ctx = gc.gfx_ctx

        font = self.get_wx_font(s, prop)
        color = gc.get_wxcolour(gc.get_rgb())
        gfx_ctx.SetFont(font, color)

        w, h, d = self.get_text_width_height_descent(s, prop, ismath)
        x = int(x)
        y = int(y - h)

        if angle == 0.0:
            gfx_ctx.DrawText(s, x, y)
        else:
            rads = math.radians(angle)
            xo = h * math.sin(rads)
            yo = h * math.cos(rads)
            gfx_ctx.DrawRotatedText(s, x - xo, y - yo, rads)

        gc.unselect()

    def new_gc(self):
        # docstring inherited
        DEBUG_MSG('new_gc()', 2, self)
        self.gc = GraphicsContextWx(self.bitmap, self)
        self.gc.select()
        self.gc.unselect()
        return self.gc

    def get_gc(self):
        """
        Fetch the locally cached gc.
        """
        # This is a dirty hack to allow anything with access to a renderer to
        # access the current graphics context
        assert self.gc is not None, "gc must be defined"
        return self.gc

    def get_wx_font(self, s, prop):
        """
        Return a wx font.  Cache instances in a font dictionary for
        efficiency
        """
        DEBUG_MSG("get_wx_font()", 1, self)

        key = hash(prop)
        fontprop = prop
        fontname = fontprop.get_name()

        font = self.fontd.get(key)
        if font is not None:
            return font

        # Allow use of platform independent and dependent font names
        wxFontname = self.fontnames.get(fontname, wx.ROMAN)
        wxFacename = ''  # Empty => wxPython chooses based on wx_fontname

        # Font colour is determined by the active wx.Pen
        # TODO: It may be wise to cache font information
        size = self.points_to_pixels(fontprop.get_size_in_points())

        font = wx.Font(int(size + 0.5),             # Size
                       wxFontname,                # 'Generic' name
                       self.fontangles[fontprop.get_style()],   # Angle
                       self.fontweights[fontprop.get_weight()],  # Weight
                       False,                     # Underline
                       wxFacename)                # Platform font name

        # cache the font and gc and return it
        self.fontd[key] = font

        return font

    def points_to_pixels(self, points):
        # docstring inherited
        return points * (PIXELS_PER_INCH / 72.0 * self.dpi / 72.0)


class GraphicsContextWx(GraphicsContextBase):
    """
    The graphics context provides the color, line styles, etc...

    This class stores a reference to a wxMemoryDC, and a
    wxGraphicsContext that draws to it.  Creating a wxGraphicsContext
    seems to be fairly heavy, so these objects are cached based on the
    bitmap object that is passed in.

    The base GraphicsContext stores colors as a RGB tuple on the unit
    interval, e.g., (0.5, 0.0, 1.0).  wxPython uses an int interval, but
    since wxPython colour management is rather simple, I have not chosen
    to implement a separate colour manager class.
    """
    _capd = {'butt': wx.CAP_BUTT,
             'projecting': wx.CAP_PROJECTING,
             'round': wx.CAP_ROUND}

    _joind = {'bevel': wx.JOIN_BEVEL,
              'miter': wx.JOIN_MITER,
              'round': wx.JOIN_ROUND}

    _cache = weakref.WeakKeyDictionary()

    def __init__(self, bitmap, renderer):
        GraphicsContextBase.__init__(self)
        # assert self.Ok(), "wxMemoryDC not OK to use"
        DEBUG_MSG("__init__()", 1, self)
        DEBUG_MSG("__init__() 2: %s" % bitmap, 1, self)

        dc, gfx_ctx = self._cache.get(bitmap, (None, None))
        if dc is None:
            dc = wx.MemoryDC()
            dc.SelectObject(bitmap)
            gfx_ctx = wx.GraphicsContext.Create(dc)
            gfx_ctx._lastcliprect = None
            self._cache[bitmap] = dc, gfx_ctx

        self.bitmap = bitmap
        self.dc = dc
        self.gfx_ctx = gfx_ctx
        self._pen = wx.Pen('BLACK', 1, wx.SOLID)
        gfx_ctx.SetPen(self._pen)
        self.renderer = renderer

    def select(self):
        """Select the current bitmap into this wxDC instance."""
        if sys.platform == 'win32':
            self.dc.SelectObject(self.bitmap)
            self.IsSelected = True

    def unselect(self):
        """Select a Null bitmap into this wxDC instance."""
        if sys.platform == 'win32':
            self.dc.SelectObject(wx.NullBitmap)
            self.IsSelected = False

    def set_foreground(self, fg, isRGBA=None):
        # docstring inherited
        # Implementation note: wxPython has a separate concept of pen and
        # brush - the brush fills any outline trace left by the pen.
        # Here we set both to the same colour - if a figure is not to be
        # filled, the renderer will set the brush to be transparent
        # Same goes for text foreground...
        DEBUG_MSG("set_foreground()", 1, self)
        self.select()
        GraphicsContextBase.set_foreground(self, fg, isRGBA)

        self._pen.SetColour(self.get_wxcolour(self.get_rgb()))
        self.gfx_ctx.SetPen(self._pen)
        self.unselect()

    def set_linewidth(self, w):
        # docstring inherited
        w = float(w)
        DEBUG_MSG("set_linewidth()", 1, self)
        self.select()
        if 0 < w < 1:
            w = 1
        GraphicsContextBase.set_linewidth(self, w)
        lw = int(self.renderer.points_to_pixels(self._linewidth))
        if lw == 0:
            lw = 1
        self._pen.SetWidth(lw)
        self.gfx_ctx.SetPen(self._pen)
        self.unselect()

    def set_capstyle(self, cs):
        # docstring inherited
        DEBUG_MSG("set_capstyle()", 1, self)
        self.select()
        GraphicsContextBase.set_capstyle(self, cs)
        self._pen.SetCap(GraphicsContextWx._capd[self._capstyle])
        self.gfx_ctx.SetPen(self._pen)
        self.unselect()

    def set_joinstyle(self, js):
        # docstring inherited
        DEBUG_MSG("set_joinstyle()", 1, self)
        self.select()
        GraphicsContextBase.set_joinstyle(self, js)
        self._pen.SetJoin(GraphicsContextWx._joind[self._joinstyle])
        self.gfx_ctx.SetPen(self._pen)
        self.unselect()

    def get_wxcolour(self, color):
        """return a wx.Colour from RGB format"""
        DEBUG_MSG("get_wx_color()", 1, self)
        if len(color) == 3:
            r, g, b = color
            r *= 255
            g *= 255
            b *= 255
            return wx.Colour(red=int(r), green=int(g), blue=int(b))
        else:
            r, g, b, a = color
            r *= 255
            g *= 255
            b *= 255
            a *= 255
            return wx.Colour(
                red=int(r),
                green=int(g),
                blue=int(b),
                alpha=int(a))


class _FigureCanvasWxBase(FigureCanvasBase, wx.Panel):
    """
    The FigureCanvas contains the figure and does event handling.

    In the wxPython backend, it is derived from wxPanel, and (usually) lives
    inside a frame instantiated by a FigureManagerWx. The parent window
    probably implements a wx.Sizer to control the displayed control size - but
    we give a hint as to our preferred minimum size.
    """

    required_interactive_framework = "wx"

    keyvald = {
        wx.WXK_CONTROL: 'control',
        wx.WXK_SHIFT: 'shift',
        wx.WXK_ALT: 'alt',
        wx.WXK_LEFT: 'left',
        wx.WXK_UP: 'up',
        wx.WXK_RIGHT: 'right',
        wx.WXK_DOWN: 'down',
        wx.WXK_ESCAPE: 'escape',
        wx.WXK_F1: 'f1',
        wx.WXK_F2: 'f2',
        wx.WXK_F3: 'f3',
        wx.WXK_F4: 'f4',
        wx.WXK_F5: 'f5',
        wx.WXK_F6: 'f6',
        wx.WXK_F7: 'f7',
        wx.WXK_F8: 'f8',
        wx.WXK_F9: 'f9',
        wx.WXK_F10: 'f10',
        wx.WXK_F11: 'f11',
        wx.WXK_F12: 'f12',
        wx.WXK_SCROLL: 'scroll_lock',
        wx.WXK_PAUSE: 'break',
        wx.WXK_BACK: 'backspace',
        wx.WXK_RETURN: 'enter',
        wx.WXK_INSERT: 'insert',
        wx.WXK_DELETE: 'delete',
        wx.WXK_HOME: 'home',
        wx.WXK_END: 'end',
        wx.WXK_PAGEUP: 'pageup',
        wx.WXK_PAGEDOWN: 'pagedown',
        wx.WXK_NUMPAD0: '0',
        wx.WXK_NUMPAD1: '1',
        wx.WXK_NUMPAD2: '2',
        wx.WXK_NUMPAD3: '3',
        wx.WXK_NUMPAD4: '4',
        wx.WXK_NUMPAD5: '5',
        wx.WXK_NUMPAD6: '6',
        wx.WXK_NUMPAD7: '7',
        wx.WXK_NUMPAD8: '8',
        wx.WXK_NUMPAD9: '9',
        wx.WXK_NUMPAD_ADD: '+',
        wx.WXK_NUMPAD_SUBTRACT: '-',
        wx.WXK_NUMPAD_MULTIPLY: '*',
        wx.WXK_NUMPAD_DIVIDE: '/',
        wx.WXK_NUMPAD_DECIMAL: 'dec',
        wx.WXK_NUMPAD_ENTER: 'enter',
        wx.WXK_NUMPAD_UP: 'up',
        wx.WXK_NUMPAD_RIGHT: 'right',
        wx.WXK_NUMPAD_DOWN: 'down',
        wx.WXK_NUMPAD_LEFT: 'left',
        wx.WXK_NUMPAD_PAGEUP: 'pageup',
        wx.WXK_NUMPAD_PAGEDOWN: 'pagedown',
        wx.WXK_NUMPAD_HOME: 'home',
        wx.WXK_NUMPAD_END: 'end',
        wx.WXK_NUMPAD_INSERT: 'insert',
        wx.WXK_NUMPAD_DELETE: 'delete',
    }

    def __init__(self, parent, id, figure):
        """
        Initialise a FigureWx instance.

        - Initialise the FigureCanvasBase and wxPanel parents.
        - Set event handlers for:
          EVT_SIZE  (Resize event)
          EVT_PAINT (Paint event)
        """

        FigureCanvasBase.__init__(self, figure)
        # Set preferred window size hint - helps the sizer (if one is
        # connected)
        l, b, w, h = figure.bbox.bounds
        w = math.ceil(w)
        h = math.ceil(h)

        wx.Panel.__init__(self, parent, id, size=wx.Size(w, h))

        # Create the drawing bitmap
        self.bitmap = wx.Bitmap(w, h)
        DEBUG_MSG("__init__() - bitmap w:%d h:%d" % (w, h), 2, self)
        # TODO: Add support for 'point' inspection and plot navigation.
        self._isDrawn = False

        self.Bind(wx.EVT_SIZE, self._onSize)
        self.Bind(wx.EVT_PAINT, self._onPaint)
        self.Bind(wx.EVT_KEY_DOWN, self._onKeyDown)
        self.Bind(wx.EVT_KEY_UP, self._onKeyUp)
        self.Bind(wx.EVT_LEFT_DOWN, self._onMouseButton)
        self.Bind(wx.EVT_LEFT_DCLICK, self._onMouseButton)
        self.Bind(wx.EVT_LEFT_UP, self._onMouseButton)
        self.Bind(wx.EVT_MIDDLE_DOWN, self._onMouseButton)
        self.Bind(wx.EVT_MIDDLE_DCLICK, self._onMouseButton)
        self.Bind(wx.EVT_MIDDLE_UP, self._onMouseButton)
        self.Bind(wx.EVT_RIGHT_DOWN, self._onMouseButton)
        self.Bind(wx.EVT_RIGHT_DCLICK, self._onMouseButton)
        self.Bind(wx.EVT_RIGHT_UP, self._onMouseButton)
        self.Bind(wx.EVT_MOUSEWHEEL, self._onMouseWheel)
        self.Bind(wx.EVT_MOTION, self._onMotion)
        self.Bind(wx.EVT_LEAVE_WINDOW, self._onLeave)
        self.Bind(wx.EVT_ENTER_WINDOW, self._onEnter)

        self.Bind(wx.EVT_MOUSE_CAPTURE_CHANGED, self._onCaptureLost)
        self.Bind(wx.EVT_MOUSE_CAPTURE_LOST, self._onCaptureLost)

        self.SetBackgroundStyle(wx.BG_STYLE_PAINT)  # Reduce flicker.
        self.SetBackgroundColour(wx.WHITE)

    def Copy_to_Clipboard(self, event=None):
        "copy bitmap of canvas to system clipboard"
        bmp_obj = wx.BitmapDataObject()
        bmp_obj.SetBitmap(self.bitmap)

        if not wx.TheClipboard.IsOpened():
            open_success = wx.TheClipboard.Open()
            if open_success:
                wx.TheClipboard.SetData(bmp_obj)
                wx.TheClipboard.Close()
                wx.TheClipboard.Flush()

    def draw_idle(self):
        # docstring inherited
        DEBUG_MSG("draw_idle()", 1, self)
        self._isDrawn = False  # Force redraw
        # Triggering a paint event is all that is needed to defer drawing
        # until later. The platform will send the event when it thinks it is
        # a good time (usually as soon as there are no other events pending).
        self.Refresh(eraseBackground=False)

    def new_timer(self, *args, **kwargs):
        # docstring inherited
        return TimerWx(*args, **kwargs)

    def flush_events(self):
        # docstring inherited
        wx.Yield()

    def start_event_loop(self, timeout=0):
        # docstring inherited
        if hasattr(self, '_event_loop'):
            raise RuntimeError("Event loop already running")
        timer = wx.Timer(self, id=wx.ID_ANY)
        if timeout > 0:
            timer.Start(timeout * 1000, oneShot=True)
            self.Bind(wx.EVT_TIMER, self.stop_event_loop, id=timer.GetId())
        # Event loop handler for start/stop event loop
        self._event_loop = wx.GUIEventLoop()
        self._event_loop.Run()
        timer.Stop()

    def stop_event_loop(self, event=None):
        # docstring inherited
        if hasattr(self, '_event_loop'):
            if self._event_loop.IsRunning():
                self._event_loop.Exit()
            del self._event_loop

    def _get_imagesave_wildcards(self):
        'return the wildcard string for the filesave dialog'
        default_filetype = self.get_default_filetype()
        filetypes = self.get_supported_filetypes_grouped()
        sorted_filetypes = sorted(filetypes.items())
        wildcards = []
        extensions = []
        filter_index = 0
        for i, (name, exts) in enumerate(sorted_filetypes):
            ext_list = ';'.join(['*.%s' % ext for ext in exts])
            extensions.append(exts[0])
            wildcard = '%s (%s)|%s' % (name, ext_list, ext_list)
            if default_filetype in exts:
                filter_index = i
            wildcards.append(wildcard)
        wildcards = '|'.join(wildcards)
        return wildcards, extensions, filter_index

    def gui_repaint(self, drawDC=None, origin='WX'):
        """
        Performs update of the displayed image on the GUI canvas, using the
        supplied wx.PaintDC device context.

        The 'WXAgg' backend sets origin accordingly.
        """
        DEBUG_MSG("gui_repaint()", 1, self)
        if self.IsShownOnScreen():
            if not drawDC:
                # not called from OnPaint use a ClientDC
                drawDC = wx.ClientDC(self)

            # following is for 'WX' backend on Windows
            # the bitmap can not be in use by another DC,
            # see GraphicsContextWx._cache
            if wx.Platform == '__WXMSW__' and origin == 'WX':
                img = self.bitmap.ConvertToImage()
                bmp = img.ConvertToBitmap()
                drawDC.DrawBitmap(bmp, 0, 0)
            else:
                drawDC.DrawBitmap(self.bitmap, 0, 0)

    filetypes = {
        **FigureCanvasBase.filetypes,
        'bmp': 'Windows bitmap',
        'jpeg': 'JPEG',
        'jpg': 'JPEG',
        'pcx': 'PCX',
        'png': 'Portable Network Graphics',
        'tif': 'Tagged Image Format File',
        'tiff': 'Tagged Image Format File',
        'xpm': 'X pixmap',
    }

    def print_figure(self, filename, *args, **kwargs):
        # docstring inherited
        super().print_figure(filename, *args, **kwargs)
        # Restore the current view; this is needed because the artist contains
        # methods rely on particular attributes of the rendered figure for
        # determining things like bounding boxes.
        if self._isDrawn:
            self.draw()

    def _onPaint(self, evt):
        """
        Called when wxPaintEvt is generated
        """

        DEBUG_MSG("_onPaint()", 1, self)
        drawDC = wx.PaintDC(self)
        if not self._isDrawn:
            self.draw(drawDC=drawDC)
        else:
            self.gui_repaint(drawDC=drawDC)
        drawDC.Destroy()

    def _onSize(self, evt):
        """
        Called when wxEventSize is generated.

        In this application we attempt to resize to fit the window, so it
        is better to take the performance hit and redraw the whole window.
        """

        DEBUG_MSG("_onSize()", 2, self)
        sz = self.GetParent().GetSizer()
        if sz:
            si = sz.GetItem(self)
        if sz and si and not si.Proportion and not si.Flag & wx.EXPAND:
            # managed by a sizer, but with a fixed size
            size = self.GetMinSize()
        else:
            # variable size
            size = self.GetClientSize()
            # Do not allow size to become smaller than MinSize
            size.IncTo(self.GetMinSize())
        if getattr(self, "_width", None):
            if size == (self._width, self._height):
                # no change in size
                return
        self._width, self._height = size
        # Create a new, correctly sized bitmap
        self.bitmap = wx.Bitmap(self._width, self._height)

        self._isDrawn = False

        if self._width <= 1 or self._height <= 1:
            return  # Empty figure

        dpival = self.figure.dpi
        winch = self._width / dpival
        hinch = self._height / dpival
        self.figure.set_size_inches(winch, hinch, forward=False)

        # Rendering will happen on the associated paint event
        # so no need to do anything here except to make sure
        # the whole background is repainted.
        self.Refresh(eraseBackground=False)
        FigureCanvasBase.resize_event(self)

    def _get_key(self, evt):

        keyval = evt.KeyCode
        if keyval in self.keyvald:
            key = self.keyvald[keyval]
        elif keyval < 256:
            key = chr(keyval)
            # wx always returns an uppercase, so make it lowercase if the shift
            # key is not depressed (NOTE: this will not handle Caps Lock)
            if not evt.ShiftDown():
                key = key.lower()
        else:
            key = None

        for meth, prefix in (
                [evt.AltDown, 'alt'],
                [evt.ControlDown, 'ctrl'], ):
            if meth():
                key = '{0}+{1}'.format(prefix, key)

        return key

    def _onKeyDown(self, evt):
        """Capture key press."""
        key = self._get_key(evt)
        FigureCanvasBase.key_press_event(self, key, guiEvent=evt)
        if self:
            evt.Skip()

    def _onKeyUp(self, evt):
        """Release key."""
        key = self._get_key(evt)
        FigureCanvasBase.key_release_event(self, key, guiEvent=evt)
        if self:
            evt.Skip()

    def _set_capture(self, capture=True):
        """Control wx mouse capture."""
        if self.HasCapture():
            self.ReleaseMouse()
        if capture:
            self.CaptureMouse()

    def _onCaptureLost(self, evt):
        """Capture changed or lost"""
        self._set_capture(False)

    def _onMouseButton(self, evt):
        """Start measuring on an axis."""
        evt.Skip()
        self._set_capture(evt.ButtonDown() or evt.ButtonDClick())
        x = evt.X
        y = self.figure.bbox.height - evt.Y
        button_map = {
            wx.MOUSE_BTN_LEFT: MouseButton.LEFT,
            wx.MOUSE_BTN_MIDDLE: MouseButton.MIDDLE,
            wx.MOUSE_BTN_RIGHT: MouseButton.RIGHT,
        }
        button = evt.GetButton()
        button = button_map.get(button, button)
        if evt.ButtonDown():
            self.button_press_event(x, y, button, guiEvent=evt)
        elif evt.ButtonDClick():
            self.button_press_event(x, y, button, dblclick=True, guiEvent=evt)
        elif evt.ButtonUp():
            self.button_release_event(x, y, button, guiEvent=evt)

    def _onMouseWheel(self, evt):
        """Translate mouse wheel events into matplotlib events"""

        # Determine mouse location
        x = evt.GetX()
        y = self.figure.bbox.height - evt.GetY()

        # Convert delta/rotation/rate into a floating point step size
        delta = evt.GetWheelDelta()
        rotation = evt.GetWheelRotation()
        rate = evt.GetLinesPerAction()
        step = rate * rotation / delta

        # Done handling event
        evt.Skip()

        # Mac is giving two events for every wheel event
        # Need to skip every second one
        if wx.Platform == '__WXMAC__':
            if not hasattr(self, '_skipwheelevent'):
                self._skipwheelevent = True
            elif self._skipwheelevent:
                self._skipwheelevent = False
                return  # Return without processing event
            else:
                self._skipwheelevent = True

        FigureCanvasBase.scroll_event(self, x, y, step, guiEvent=evt)

    def _onMotion(self, evt):
        """Start measuring on an axis."""
        x = evt.GetX()
        y = self.figure.bbox.height - evt.GetY()
        evt.Skip()
        FigureCanvasBase.motion_notify_event(self, x, y, guiEvent=evt)

    def _onLeave(self, evt):
        """Mouse has left the window."""
        evt.Skip()
        FigureCanvasBase.leave_notify_event(self, guiEvent=evt)

    def _onEnter(self, evt):
        """Mouse has entered the window."""
        x = evt.GetX()
        y = self.figure.bbox.height - evt.GetY()
        evt.Skip()
        FigureCanvasBase.enter_notify_event(self, guiEvent=evt, xy=(x, y))


class FigureCanvasWx(_FigureCanvasWxBase):
    # Rendering to a Wx canvas using the deprecated Wx renderer.

    def draw(self, drawDC=None):
        """
        Render the figure using RendererWx instance renderer, or using a
        previously defined renderer if none is specified.
        """
        DEBUG_MSG("draw()", 1, self)
        self.renderer = RendererWx(self.bitmap, self.figure.dpi)
        self.figure.draw(self.renderer)
        self._isDrawn = True
        self.gui_repaint(drawDC=drawDC)

    def print_bmp(self, filename, *args, **kwargs):
        return self._print_image(filename, wx.BITMAP_TYPE_BMP, *args, **kwargs)

    if not _has_pil:
        def print_jpeg(self, filename, *args, **kwargs):
            return self._print_image(filename, wx.BITMAP_TYPE_JPEG,
                                     *args, **kwargs)
        print_jpg = print_jpeg

    def print_pcx(self, filename, *args, **kwargs):
        return self._print_image(filename, wx.BITMAP_TYPE_PCX, *args, **kwargs)

    def print_png(self, filename, *args, **kwargs):
        return self._print_image(filename, wx.BITMAP_TYPE_PNG, *args, **kwargs)

    if not _has_pil:
        def print_tiff(self, filename, *args, **kwargs):
            return self._print_image(filename, wx.BITMAP_TYPE_TIF,
                                     *args, **kwargs)
        print_tif = print_tiff

    def print_xpm(self, filename, *args, **kwargs):
        return self._print_image(filename, wx.BITMAP_TYPE_XPM, *args, **kwargs)

    def _print_image(self, filename, filetype, *args, **kwargs):
        origBitmap = self.bitmap

        l, b, width, height = self.figure.bbox.bounds
        width = math.ceil(width)
        height = math.ceil(height)

        self.bitmap = wx.Bitmap(width, height)

        renderer = RendererWx(self.bitmap, self.figure.dpi)

        gc = renderer.new_gc()

        self.figure.draw(renderer)

        # image is the object that we call SaveFile on.
        image = self.bitmap
        # set the JPEG quality appropriately.  Unfortunately, it is only
        # possible to set the quality on a wx.Image object.  So if we
        # are saving a JPEG, convert the wx.Bitmap to a wx.Image,
        # and set the quality.
        if filetype == wx.BITMAP_TYPE_JPEG:
            jpeg_quality = kwargs.get('quality',
                                      rcParams['savefig.jpeg_quality'])
            image = self.bitmap.ConvertToImage()
            image.SetOption(wx.IMAGE_OPTION_QUALITY, str(jpeg_quality))

        # Now that we have rendered into the bitmap, save it to the appropriate
        # file type and clean up.
        if isinstance(filename, str):
            if not image.SaveFile(filename, filetype):
                raise RuntimeError(f'Could not save figure to {filename}')
        elif cbook.is_writable_file_like(filename):
            if not isinstance(image, wx.Image):
                image = image.ConvertToImage()
            if not image.SaveStream(filename, filetype):
                raise RuntimeError(f'Could not save figure to {filename}')

        # Restore everything to normal
        self.bitmap = origBitmap

        # Note: draw is required here since bits of state about the
        # last renderer are strewn about the artist draw methods.  Do
        # not remove the draw without first verifying that these have
        # been cleaned up.  The artist contains() methods will fail
        # otherwise.
        if self._isDrawn:
            self.draw()
        self.Refresh()


########################################################################
#
# The following functions and classes are for pylab compatibility
# mode (matplotlib.pylab) and implement figure managers, etc...
#
########################################################################


class FigureFrameWx(wx.Frame):
    def __init__(self, num, fig):
        # On non-Windows platform, explicitly set the position - fix
        # positioning bug on some Linux platforms
        if wx.Platform == '__WXMSW__':
            pos = wx.DefaultPosition
        else:
            pos = wx.Point(20, 20)
        wx.Frame.__init__(self, parent=None, id=-1, pos=pos,
                          title="Figure %d" % num)
        # Frame will be sized later by the Fit method
        DEBUG_MSG("__init__()", 1, self)
        self.num = num
        _set_frame_icon(self)

        self.canvas = self.get_canvas(fig)
        self.canvas.SetInitialSize(wx.Size(fig.bbox.width, fig.bbox.height))
        self.canvas.SetFocus()
        self.sizer = wx.BoxSizer(wx.VERTICAL)
        self.sizer.Add(self.canvas, 1, wx.TOP | wx.LEFT | wx.EXPAND)
        # By adding toolbar in sizer, we are able to put it at the bottom
        # of the frame - so appearance is closer to GTK version

        self.toolmanager = self._get_toolmanager()
        statusbar = (StatusbarWx(self, self.toolmanager)
                     if self.toolmanager else StatusBarWx(self))
        self.SetStatusBar(statusbar)
        self.toolbar = self._get_toolbar()

        if self.toolmanager:
            backend_tools.add_tools_to_manager(self.toolmanager)
            if self.toolbar:
                backend_tools.add_tools_to_container(self.toolbar)

        if self.toolbar is not None:
            self.toolbar.Realize()
            # On Windows platform, default window size is incorrect, so set
            # toolbar width to figure width.
            tw, th = self.toolbar.GetSize()
            fw, fh = self.canvas.GetSize()
            # By adding toolbar in sizer, we are able to put it at the bottom
            # of the frame - so appearance is closer to GTK version.
            self.toolbar.SetSize(wx.Size(fw, th))
            self.sizer.Add(self.toolbar, 0, wx.LEFT | wx.EXPAND)
        self.SetSizer(self.sizer)
        self.Fit()

        self.canvas.SetMinSize((2, 2))

        self.figmgr = FigureManagerWx(self.canvas, num, self)

        self.Bind(wx.EVT_CLOSE, self._onClose)

    @cbook.deprecated("3.2", alternative="self.GetStatusBar()")
    @property
    def statusbar(self):
        return self.GetStatusBar()

    def _get_toolbar(self):
        if rcParams['toolbar'] == 'toolbar2':
            toolbar = NavigationToolbar2Wx(self.canvas)
        elif matplotlib.rcParams['toolbar'] == 'toolmanager':
            toolbar = ToolbarWx(self.toolmanager, self)
        else:
            toolbar = None
        return toolbar

    def _get_toolmanager(self):
        if matplotlib.rcParams['toolbar'] == 'toolmanager':
            toolmanager = ToolManager(self.canvas.figure)
        else:
            toolmanager = None
        return toolmanager

    def get_canvas(self, fig):
        return FigureCanvasWx(self, -1, fig)

    def get_figure_manager(self):
        DEBUG_MSG("get_figure_manager()", 1, self)
        return self.figmgr

    def _onClose(self, evt):
        DEBUG_MSG("onClose()", 1, self)
        self.canvas.close_event()
        self.canvas.stop_event_loop()
        Gcf.destroy(self.num)
        # self.Destroy()

    def GetToolBar(self):
        """Override wxFrame::GetToolBar as we don't have managed toolbar"""
        return self.toolbar

    def Destroy(self, *args, **kwargs):
        try:
            self.canvas.mpl_disconnect(self.toolbar._idDrag)
            # Rationale for line above: see issue 2941338.
        except AttributeError:
            pass  # classic toolbar lacks the attribute
        if not self.IsBeingDeleted():
            wx.Frame.Destroy(self, *args, **kwargs)
            if self.toolbar is not None:
                self.toolbar.Destroy()
            wxapp = wx.GetApp()
            if wxapp:
                wxapp.Yield()
        return True


class FigureManagerWx(FigureManagerBase):
    """
    This class contains the FigureCanvas and GUI frame

    It is instantiated by GcfWx whenever a new figure is created. GcfWx is
    responsible for managing multiple instances of FigureManagerWx.

    Attributes
    ----------
    canvas : `FigureCanvas`
        a FigureCanvasWx(wx.Panel) instance
    window : wxFrame
        a wxFrame instance - wxpython.org/Phoenix/docs/html/Frame.html

    """

    def __init__(self, canvas, num, frame):
        DEBUG_MSG("__init__()", 1, self)
        FigureManagerBase.__init__(self, canvas, num)
        self.frame = frame
        self.window = frame

        self.toolmanager = getattr(frame, "toolmanager", None)
        self.toolbar = frame.GetToolBar()

    def show(self):
        self.frame.Show()
        self.canvas.draw()

    def destroy(self, *args):
        DEBUG_MSG("destroy()", 1, self)
        self.frame.Destroy()
        wxapp = wx.GetApp()
        if wxapp:
            wxapp.Yield()

    def get_window_title(self):
        return self.window.GetTitle()

    def set_window_title(self, title):
        self.window.SetTitle(title)

    def resize(self, width, height):
        'Set the canvas size in pixels'
        self.canvas.SetInitialSize(wx.Size(width, height))
        self.window.GetSizer().Fit(self.window)


def _load_bitmap(filename):
    """
    Load a bitmap file from the backends/images subdirectory in which the
    matplotlib library is installed. The filename parameter should not
    contain any path information as this is determined automatically.

    Returns a wx.Bitmap object.
    """
    path = cbook._get_data_path('images', filename)
    if not path.exists():
        raise IOError(f"Could not find bitmap file '{path}'; dying")
    return wx.Bitmap(str(path))


def _set_frame_icon(frame):
    bundle = wx.IconBundle()
    for image in ('matplotlib.png', 'matplotlib_large.png'):
        try:
            icon = wx.Icon(_load_bitmap(image))
        except IOError:
            continue
        if not icon.IsOk():
            return
        bundle.AddIcon(icon)
    frame.SetIcons(bundle)


@cbook.deprecated("3.1")
class MenuButtonWx(wx.Button):
    """
    wxPython does not permit a menu to be incorporated directly into a toolbar.
    This class simulates the effect by associating a pop-up menu with a button
    in the toolbar, and managing this as though it were a menu.
    """

    def __init__(self, parent):

        wx.Button.__init__(self, parent, wx.ID_ANY, "Axes:        ",
                           style=wx.BU_EXACTFIT)
        self._toolbar = parent
        self._menu = wx.Menu()
        self._axisId = []
        # First two menu items never change...
        self._allId = wx.NewId()
        self._invertId = wx.NewId()
        self._menu.Append(self._allId, "All", "Select all axes", False)
        self._menu.Append(self._invertId, "Invert", "Invert axes selected",
                          False)
        self._menu.AppendSeparator()

        self.Bind(wx.EVT_BUTTON, self._onMenuButton, id=self.GetId())
        self.Bind(wx.EVT_MENU, self._handleSelectAllAxes, id=self._allId)
        self.Bind(wx.EVT_MENU, self._handleInvertAxesSelected,
                  id=self._invertId)

    def Destroy(self):
        self._menu.Destroy()
        self.Destroy()

    def _onMenuButton(self, evt):
        """Handle menu button pressed."""
        x, y = self.GetPosition()
        w, h = self.GetSize()
        self.PopupMenuXY(self._menu, x, y + h - 4)
        # When menu returned, indicate selection in button
        evt.Skip()

    def _handleSelectAllAxes(self, evt):
        """Called when the 'select all axes' menu item is selected."""
        if len(self._axisId) == 0:
            return
        for i in range(len(self._axisId)):
            self._menu.Check(self._axisId[i], True)
        self._toolbar.set_active(self.getActiveAxes())
        evt.Skip()

    def _handleInvertAxesSelected(self, evt):
        """Called when the invert all menu item is selected"""
        if len(self._axisId) == 0:
            return
        for i in range(len(self._axisId)):
            if self._menu.IsChecked(self._axisId[i]):
                self._menu.Check(self._axisId[i], False)
            else:
                self._menu.Check(self._axisId[i], True)
        self._toolbar.set_active(self.getActiveAxes())
        evt.Skip()

    def _onMenuItemSelected(self, evt):
        """Called whenever one of the specific axis menu items is selected"""
        current = self._menu.IsChecked(evt.GetId())
        if current:
            new = False
        else:
            new = True
        self._menu.Check(evt.GetId(), new)
        # Lines above would be deleted based on svn tracker ID 2841525;
        # not clear whether this matters or not.
        self._toolbar.set_active(self.getActiveAxes())
        evt.Skip()

    def updateAxes(self, maxAxis):
        """Ensures that there are entries for max_axis axes in the menu
        (selected by default)."""
        if maxAxis > len(self._axisId):
            for i in range(len(self._axisId) + 1, maxAxis + 1):
                menuId = wx.NewId()
                self._axisId.append(menuId)
                self._menu.Append(menuId, "Axis %d" % i,
                                  "Select axis %d" % i,
                                  True)
                self._menu.Check(menuId, True)
                self.Bind(wx.EVT_MENU, self._onMenuItemSelected, id=menuId)
        elif maxAxis < len(self._axisId):
            for menuId in self._axisId[maxAxis:]:
                self._menu.Delete(menuId)
            self._axisId = self._axisId[:maxAxis]
        self._toolbar.set_active(list(range(maxAxis)))

    def getActiveAxes(self):
        """Return a list of the selected axes."""
        active = [idx for idx, ax_id in enumerate(self._axisId)
                  if self._menu.IsChecked(ax_id)]
        return active

    def updateButtonText(self, lst):
        """Update the list of selected axes in the menu button."""
        self.SetLabel(
            'Axes: ' + ','.join('%d' % (e + 1) for e in lst))


cursord = {
    cursors.MOVE: wx.CURSOR_HAND,
    cursors.HAND: wx.CURSOR_HAND,
    cursors.POINTER: wx.CURSOR_ARROW,
    cursors.SELECT_REGION: wx.CURSOR_CROSS,
    cursors.WAIT: wx.CURSOR_WAIT,
}


class NavigationToolbar2Wx(NavigationToolbar2, wx.ToolBar):
    def __init__(self, canvas):
        wx.ToolBar.__init__(self, canvas.GetParent(), -1)
        NavigationToolbar2.__init__(self, canvas)
        self.canvas = canvas
        self._idle = True
        self.prevZoomRect = None
        # for now, use alternate zoom-rectangle drawing on all
        # Macs. N.B. In future versions of wx it may be possible to
        # detect Retina displays with window.GetContentScaleFactor()
        # and/or dc.GetContentScaleFactor()
        self.retinaFix = 'wxMac' in wx.PlatformInfo

    def get_canvas(self, frame, fig):
        return type(self.canvas)(frame, -1, fig)

    def _init_toolbar(self):
        DEBUG_MSG("_init_toolbar", 1, self)

        self._parent = self.canvas.GetParent()

        self.wx_ids = {}
        for text, tooltip_text, image_file, callback in self.toolitems:
            if text is None:
                self.AddSeparator()
                continue
            self.wx_ids[text] = (
                self.AddTool(
                    -1,
                    bitmap=_load_bitmap(image_file + ".png"),
                    bmpDisabled=wx.NullBitmap,
                    label=text, shortHelp=text, longHelp=tooltip_text,
                    kind=(wx.ITEM_CHECK if text in ["Pan", "Zoom"]
                          else wx.ITEM_NORMAL))
                .Id)
            self.Bind(wx.EVT_TOOL, getattr(self, callback),
                      id=self.wx_ids[text])

        self.Realize()

    def zoom(self, *args):
        self.ToggleTool(self.wx_ids['Pan'], False)
        NavigationToolbar2.zoom(self, *args)

    def pan(self, *args):
        self.ToggleTool(self.wx_ids['Zoom'], False)
        NavigationToolbar2.pan(self, *args)

    def configure_subplots(self, *args):
        global FigureManager  # placates pyflakes: created by @_Backend.export
        frame = wx.Frame(None, -1, "Configure subplots")
        _set_frame_icon(frame)

        toolfig = Figure((6, 3))
        canvas = type(self.canvas)(frame, -1, toolfig)

        # Create a figure manager to manage things
        FigureManager(canvas, 1, frame)

        # Now put all into a sizer
        sizer = wx.BoxSizer(wx.VERTICAL)
        # This way of adding to sizer allows resizing
        sizer.Add(canvas, 1, wx.LEFT | wx.TOP | wx.GROW)
        frame.SetSizer(sizer)
        frame.Fit()
        SubplotTool(self.canvas.figure, toolfig)
        frame.Show()

    def save_figure(self, *args):
        # Fetch the required filename and file type.
        filetypes, exts, filter_index = self.canvas._get_imagesave_wildcards()
        default_file = self.canvas.get_default_filename()
        dlg = wx.FileDialog(self.canvas.GetParent(),
                            "Save to file", "", default_file, filetypes,
                            wx.FD_SAVE | wx.FD_OVERWRITE_PROMPT)
        dlg.SetFilterIndex(filter_index)
        if dlg.ShowModal() == wx.ID_OK:
            dirname = dlg.GetDirectory()
            filename = dlg.GetFilename()
            DEBUG_MSG(
                'Save file dir:%s name:%s' %
                (dirname, filename), 3, self)
            format = exts[dlg.GetFilterIndex()]
            basename, ext = os.path.splitext(filename)
            if ext.startswith('.'):
                ext = ext[1:]
            if ext in ('svg', 'pdf', 'ps', 'eps', 'png') and format != ext:
                # looks like they forgot to set the image type drop
                # down, going with the extension.
                _log.warning('extension %s did not match the selected '
                             'image type %s; going with %s',
                             ext, format, ext)
                format = ext
            try:
                self.canvas.figure.savefig(
                    os.path.join(dirname, filename), format=format)
            except Exception as e:
                error_msg_wx(str(e))

    def set_cursor(self, cursor):
        cursor = wx.Cursor(cursord[cursor])
        self.canvas.SetCursor(cursor)
        self.canvas.Update()

    def press(self, event):
        if self._active == 'ZOOM':
            if not self.retinaFix:
                self.wxoverlay = wx.Overlay()
            else:
                if event.inaxes is not None:
                    self.savedRetinaImage = self.canvas.copy_from_bbox(
                        event.inaxes.bbox)
                    self.zoomStartX = event.xdata
                    self.zoomStartY = event.ydata
                    self.zoomAxes = event.inaxes

    def release(self, event):
        if self._active == 'ZOOM':
            # When the mouse is released we reset the overlay and it
            # restores the former content to the window.
            if not self.retinaFix:
                self.wxoverlay.Reset()
                del self.wxoverlay
            else:
                del self.savedRetinaImage
                if self.prevZoomRect:
                    self.prevZoomRect.pop(0).remove()
                    self.prevZoomRect = None
                if self.zoomAxes:
                    self.zoomAxes = None

    def draw_rubberband(self, event, x0, y0, x1, y1):
        if self.retinaFix:  # On Macs, use the following code
            # wx.DCOverlay does not work properly on Retina displays.
            rubberBandColor = '#C0C0FF'
            if self.prevZoomRect:
                self.prevZoomRect.pop(0).remove()
            self.canvas.restore_region(self.savedRetinaImage)
            X0, X1 = self.zoomStartX, event.xdata
            Y0, Y1 = self.zoomStartY, event.ydata
            lineX = (X0, X0, X1, X1, X0)
            lineY = (Y0, Y1, Y1, Y0, Y0)
            self.prevZoomRect = self.zoomAxes.plot(
                lineX, lineY, '-', color=rubberBandColor)
            self.zoomAxes.draw_artist(self.prevZoomRect[0])
            self.canvas.blit(self.zoomAxes.bbox)
            return

        # Use an Overlay to draw a rubberband-like bounding box.

        dc = wx.ClientDC(self.canvas)
        odc = wx.DCOverlay(self.wxoverlay, dc)
        odc.Clear()

        # Mac's DC is already the same as a GCDC, and it causes
        # problems with the overlay if we try to use an actual
        # wx.GCDC so don't try it.
        if 'wxMac' not in wx.PlatformInfo:
            dc = wx.GCDC(dc)

        height = self.canvas.figure.bbox.height
        y1 = height - y1
        y0 = height - y0

        if y1 < y0:
            y0, y1 = y1, y0
        if x1 < x0:
            x0, x1 = x1, x0

        w = x1 - x0
        h = y1 - y0
        rect = wx.Rect(x0, y0, w, h)

        rubberBandColor = '#C0C0FF'  # or load from config?

        # Set a pen for the border
        color = wx.Colour(rubberBandColor)
        dc.SetPen(wx.Pen(color, 1))

        # use the same color, plus alpha for the brush
        r, g, b, a = color.Get(True)
        color.Set(r, g, b, 0x60)
        dc.SetBrush(wx.Brush(color))
        dc.DrawRectangle(rect)

    @cbook.deprecated("3.2")
    def set_status_bar(self, statbar):
        self.GetTopLevelParent().SetStatusBar(statbar)

    @cbook.deprecated("3.2",
                      alternative="self.GetTopLevelParent().GetStatusBar()")
    @property
    def statbar(self):
        return self.GetTopLevelParent().GetStatusBar()

    def set_message(self, s):
        status_bar = self.GetTopLevelParent().GetStatusBar()
        if status_bar is not None:
            status_bar.set_function(s)

    def set_history_buttons(self):
        can_backward = self._nav_stack._pos > 0
        can_forward = self._nav_stack._pos < len(self._nav_stack._elements) - 1
        if 'Back' in self.wx_ids:
            self.EnableTool(self.wx_ids['Back'], can_backward)
        if 'Forward' in self.wx_ids:
            self.EnableTool(self.wx_ids['Forward'], can_forward)


class StatusBarWx(wx.StatusBar):
    """
    A status bar is added to _FigureFrame to allow measurements and the
    previously selected scroll function to be displayed as a user
    convenience.
    """

    def __init__(self, parent, *args, **kwargs):
        wx.StatusBar.__init__(self, parent, -1)
        self.SetFieldsCount(2)

    def set_function(self, string):
        self.SetStatusText("%s" % string, 1)


# tools for matplotlib.backend_managers.ToolManager:

class ToolbarWx(ToolContainerBase, wx.ToolBar):
    def __init__(self, toolmanager, parent, style=wx.TB_HORIZONTAL):
        ToolContainerBase.__init__(self, toolmanager)
        wx.ToolBar.__init__(self, parent, -1, style=style)
        self._toolitems = {}
        self._groups = {}

    def add_toolitem(
        self, name, group, position, image_file, description, toggle):

        before, group = self._add_to_group(group, name, position)
        idx = self.GetToolPos(before.Id)
        if image_file:
            bmp = _load_bitmap(image_file)
            kind = wx.ITEM_NORMAL if not toggle else wx.ITEM_CHECK
            tool = self.InsertTool(idx, -1, name, bmp, wx.NullBitmap, kind,
                                   description or "")
        else:
            size = (self.GetTextExtent(name)[0]+10, -1)
            if toggle:
                control = wx.ToggleButton(self, -1, name, size=size)
            else:
                control = wx.Button(self, -1, name, size=size)
            tool = self.InsertControl(idx, control, label=name)
        self.Realize()

        def handler(event):
            self.trigger_tool(name)

        if image_file:
            self.Bind(wx.EVT_TOOL, handler, tool)
        else:
            control.Bind(wx.EVT_LEFT_DOWN, handler)

        self._toolitems.setdefault(name, [])
        group.insert(position, tool)
        self._toolitems[name].append((tool, handler))

    def _add_to_group(self, group, name, position):
        gr = self._groups.get(group, [])
        if not gr:
            sep = self.AddSeparator()
            gr.append(sep)
        before = gr[position]
        self._groups[group] = gr
        return before, gr

    def toggle_toolitem(self, name, toggled):
        if name not in self._toolitems:
            return
        for tool, handler in self._toolitems[name]:
            if not tool.IsControl():
                self.ToggleTool(tool.Id, toggled)
            else:
                tool.GetControl().SetValue(toggled)
        self.Refresh()

    def remove_toolitem(self, name):
        for tool, handler in self._toolitems[name]:
            self.DeleteTool(tool.Id)
        del self._toolitems[name]


class StatusbarWx(StatusbarBase, wx.StatusBar):
    """for use with ToolManager"""
    def __init__(self, parent, *args, **kwargs):
        StatusbarBase.__init__(self, *args, **kwargs)
        wx.StatusBar.__init__(self, parent, -1)
        self.SetFieldsCount(1)
        self.SetStatusText("")

    def set_message(self, s):
        self.SetStatusText(s)


class ConfigureSubplotsWx(backend_tools.ConfigureSubplotsBase):
    def trigger(self, *args):
        NavigationToolbar2Wx.configure_subplots(
            self._make_classic_style_pseudo_toolbar())

    @cbook.deprecated("3.2")
    def configure_subplots(self):
        frame = wx.Frame(None, -1, "Configure subplots")
        _set_frame_icon(frame)

        toolfig = Figure((6, 3))
        canvas = self.get_canvas(frame, toolfig)

        # Now put all into a sizer
        sizer = wx.BoxSizer(wx.VERTICAL)
        # This way of adding to sizer allows resizing
        sizer.Add(canvas, 1, wx.LEFT | wx.TOP | wx.GROW)
        frame.SetSizer(sizer)
        frame.Fit()
        SubplotTool(self.canvas.figure, toolfig)
        frame.Show()

    @cbook.deprecated("3.2")
    def get_canvas(self, frame, fig):
        return type(self.canvas)(frame, -1, fig)


class SaveFigureWx(backend_tools.SaveFigureBase):
    def trigger(self, *args):
        NavigationToolbar2Wx.save_figure(
            self._make_classic_style_pseudo_toolbar())


class SetCursorWx(backend_tools.SetCursorBase):
    def set_cursor(self, cursor):
        NavigationToolbar2Wx.set_cursor(
            self._make_classic_style_pseudo_toolbar(), cursor)


if 'wxMac' not in wx.PlatformInfo:
    # on most platforms, use overlay
    class RubberbandWx(backend_tools.RubberbandBase):
        def __init__(self, *args, **kwargs):
            backend_tools.RubberbandBase.__init__(self, *args, **kwargs)
            self.wxoverlay = None

        def draw_rubberband(self, x0, y0, x1, y1):
            # Use an Overlay to draw a rubberband-like bounding box.
            if self.wxoverlay is None:
                self.wxoverlay = wx.Overlay()
            dc = wx.ClientDC(self.canvas)
            odc = wx.DCOverlay(self.wxoverlay, dc)
            odc.Clear()

            dc = wx.GCDC(dc)

            height = self.canvas.figure.bbox.height
            y1 = height - y1
            y0 = height - y0

            if y1 < y0:
                y0, y1 = y1, y0
            if x1 < x0:
                x0, x1 = x1, x0

            w = x1 - x0
            h = y1 - y0
            rect = wx.Rect(x0, y0, w, h)

            rubberBandColor = '#C0C0FF'  # or load from config?

            # Set a pen for the border
            color = wx.Colour(rubberBandColor)
            dc.SetPen(wx.Pen(color, 1))

            # use the same color, plus alpha for the brush
            r, g, b, a = color.Get(True)
            color.Set(r, g, b, 0x60)
            dc.SetBrush(wx.Brush(color))
            dc.DrawRectangle(rect)

        def remove_rubberband(self):
            if self.wxoverlay is None:
                return
            self.wxoverlay.Reset()
            self.wxoverlay = None

else:
    # on Mac OS retina displays DCOverlay does not work
    # and dc.SetLogicalFunction does not have an effect on any display
    # the workaround is to blit the full image for remove_rubberband
    class RubberbandWx(backend_tools.RubberbandBase):
        def __init__(self, *args, **kwargs):
            backend_tools.RubberbandBase.__init__(self, *args, **kwargs)
            self._rect = None

        def draw_rubberband(self, x0, y0, x1, y1):
            dc = wx.ClientDC(self.canvas)
            # this would be required if the Canvas is a ScrolledWindow,
            # which is not the case for now
            # self.PrepareDC(dc)

            # delete old rubberband
            if self._rect:
                self.remove_rubberband(dc)

            # draw new rubberband
            dc.SetPen(wx.Pen(wx.BLACK, 1, wx.SOLID))
            dc.SetBrush(wx.TRANSPARENT_BRUSH)
            self._rect = (x0, self.canvas._height-y0, x1-x0, -y1+y0)
            dc.DrawRectangle(self._rect)

        def remove_rubberband(self, dc=None):
            if not self._rect:
                return
            if self.canvas.bitmap:
                if dc is None:
                    dc = wx.ClientDC(self.canvas)
                dc.DrawBitmap(self.canvas.bitmap, 0, 0)
                #  for testing the method on Windows, use this code instead:
                # img = self.canvas.bitmap.ConvertToImage()
                # bmp = img.ConvertToBitmap()
                # dc.DrawBitmap(bmp, 0, 0)
            self._rect = None


class _HelpDialog(wx.Dialog):
    _instance = None  # a reference to an open dialog singleton
    headers = [("Action", "Shortcuts", "Description")]
    widths = [100, 140, 300]

    def __init__(self, parent, help_entries):
        wx.Dialog.__init__(self, parent, title="Help",
                           style=wx.DEFAULT_DIALOG_STYLE | wx.RESIZE_BORDER)

        sizer = wx.BoxSizer(wx.VERTICAL)
        grid_sizer = wx.FlexGridSizer(0, 3, 8, 6)
        # create and add the entries
        bold = self.GetFont().MakeBold()
        for r, row in enumerate(self.headers + help_entries):
            for (col, width) in zip(row, self.widths):
                label = wx.StaticText(self, label=col)
                if r == 0:
                    label.SetFont(bold)
                label.Wrap(width)
                grid_sizer.Add(label, 0, 0, 0)
        # finalize layout, create button
        sizer.Add(grid_sizer, 0, wx.ALL, 6)
        OK = wx.Button(self, wx.ID_OK)
        sizer.Add(OK, 0, wx.ALIGN_CENTER_HORIZONTAL | wx.ALL, 8)
        self.SetSizer(sizer)
        sizer.Fit(self)
        self.Layout()
        self.Bind(wx.EVT_CLOSE, self.OnClose)
        OK.Bind(wx.EVT_BUTTON, self.OnClose)

    def OnClose(self, evt):
        _HelpDialog._instance = None  # remove global reference
        self.DestroyLater()
        evt.Skip()

    @classmethod
    def show(cls, parent, help_entries):
        # if no dialog is shown, create one; otherwise just re-raise it
        if cls._instance:
            cls._instance.Raise()
            return
        cls._instance = cls(parent, help_entries)
        cls._instance.Show()


class HelpWx(backend_tools.ToolHelpBase):
    def trigger(self, *args):
        _HelpDialog.show(self.figure.canvas.GetTopLevelParent(),
                         self._get_help_entries())


class ToolCopyToClipboardWx(backend_tools.ToolCopyToClipboardBase):
    def trigger(self, *args, **kwargs):
        if not self.canvas._isDrawn:
            self.canvas.draw()
        if not self.canvas.bitmap.IsOk() or not wx.TheClipboard.Open():
            return
        try:
            wx.TheClipboard.SetData(wx.BitmapDataObject(self.canvas.bitmap))
        finally:
            wx.TheClipboard.Close()


backend_tools.ToolSaveFigure = SaveFigureWx
backend_tools.ToolConfigureSubplots = ConfigureSubplotsWx
backend_tools.ToolSetCursor = SetCursorWx
backend_tools.ToolRubberband = RubberbandWx
backend_tools.ToolHelp = HelpWx
backend_tools.ToolCopyToClipboard = ToolCopyToClipboardWx


# < Additions for printing support: Matt Newville

@cbook.deprecated("3.1")
class PrintoutWx(wx.Printout):
    """
    Simple wrapper around wx Printout class -- all the real work
    here is scaling the matplotlib canvas bitmap to the current
    printer's definition.
    """

    def __init__(self, canvas, width=5.5, margin=0.5, title='matplotlib'):
        wx.Printout.__init__(self, title=title)
        self.canvas = canvas
        # width, in inches of output figure (approximate)
        self.width = width
        self.margin = margin

    def HasPage(self, page):
        # current only supports 1 page print
        return page == 1

    def GetPageInfo(self):
        return (1, 1, 1, 1)

    def OnPrintPage(self, page):
        self.canvas.draw()

        dc = self.GetDC()
        ppw, pph = self.GetPPIPrinter()      # printer's pixels per in
        pgw, pgh = self.GetPageSizePixels()  # page size in pixels
        dcw, dch = dc.GetSize()
        grw, grh = self.canvas.GetSize()

        # save current figure dpi resolution and bg color,
        # so that we can temporarily set them to the dpi of
        # the printer, and the bg color to white
        bgcolor = self.canvas.figure.get_facecolor()
        fig_dpi = self.canvas.figure.dpi

        # draw the bitmap, scaled appropriately
        vscale = float(ppw) / fig_dpi

        # set figure resolution,bg color for printer
        self.canvas.figure.dpi = ppw
        self.canvas.figure.set_facecolor('#FFFFFF')

        renderer = RendererWx(self.canvas.bitmap, self.canvas.figure.dpi)
        self.canvas.figure.draw(renderer)
        self.canvas.bitmap.SetWidth(
            int(self.canvas.bitmap.GetWidth() * vscale))
        self.canvas.bitmap.SetHeight(
            int(self.canvas.bitmap.GetHeight() * vscale))
        self.canvas.draw()

        # page may need additional scaling on preview
        page_scale = 1.0
        if self.IsPreview():
            page_scale = float(dcw) / pgw

        # get margin in pixels = (margin in in) * (pixels/in)
        top_margin = int(self.margin * pph * page_scale)
        left_margin = int(self.margin * ppw * page_scale)

        # set scale so that width of output is self.width inches
        # (assuming grw is size of graph in inches....)
        user_scale = (self.width * fig_dpi * page_scale) / float(grw)

        dc.SetDeviceOrigin(left_margin, top_margin)
        dc.SetUserScale(user_scale, user_scale)

        # this cute little number avoid API inconsistencies in wx
        try:
            dc.DrawBitmap(self.canvas.bitmap, 0, 0)
        except Exception:
            try:
                dc.DrawBitmap(self.canvas.bitmap, (0, 0))
            except Exception:
                pass

        # restore original figure  resolution
        self.canvas.figure.set_facecolor(bgcolor)
        self.canvas.figure.dpi = fig_dpi
        self.canvas.draw()
        return True


@_Backend.export
class _BackendWx(_Backend):
    FigureCanvas = FigureCanvasWx
    FigureManager = FigureManagerWx
    _frame_class = FigureFrameWx

    @staticmethod
    def trigger_manager_draw(manager):
        manager.canvas.draw_idle()

    @classmethod
    def new_figure_manager(cls, num, *args, **kwargs):
        # Create a wx.App instance if it has not been created so far.
        wxapp = wx.GetApp()
        if wxapp is None:
            wxapp = wx.App(False)
            wxapp.SetExitOnFrameDelete(True)
            # Retain a reference to the app object so that it does not get
            # garbage collected.
            _BackendWx._theWxApp = wxapp
        return super().new_figure_manager(num, *args, **kwargs)

    @classmethod
    def new_figure_manager_given_figure(cls, num, figure):
        frame = cls._frame_class(num, figure)
        figmgr = frame.get_figure_manager()
        if matplotlib.is_interactive():
            figmgr.frame.Show()
            figure.canvas.draw_idle()
        return figmgr

    @staticmethod
    def mainloop():
        if not wx.App.IsMainLoopRunning():
            wxapp = wx.GetApp()
            if wxapp is not None:
                wxapp.MainLoop()