backend_qt5.py 29.7 KB
Newer Older
xuebingbing's avatar
xuebingbing committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865
from __future__ import (absolute_import, division, print_function,
                        unicode_literals)
import six

import os
import re
import signal
import sys
from six import unichr

import matplotlib

from matplotlib.cbook import is_string_like
from matplotlib.backend_bases import FigureManagerBase
from matplotlib.backend_bases import FigureCanvasBase
from matplotlib.backend_bases import NavigationToolbar2

from matplotlib.backend_bases import cursors
from matplotlib.backend_bases import TimerBase
from matplotlib.backend_bases import ShowBase

from matplotlib._pylab_helpers import Gcf
from matplotlib.figure import Figure

from matplotlib.widgets import SubplotTool
import matplotlib.backends.qt_editor.figureoptions as figureoptions

from .qt_compat import (QtCore, QtGui, QtWidgets, _getSaveFileName,
                        __version__, is_pyqt5)
from matplotlib.backends.qt_editor.formsubplottool import UiSubplotTool

backend_version = __version__

# SPECIAL_KEYS are keys that do *not* return their unicode name
# instead they have manually specified names
SPECIAL_KEYS = {QtCore.Qt.Key_Control: 'control',
                QtCore.Qt.Key_Shift: 'shift',
                QtCore.Qt.Key_Alt: 'alt',
                QtCore.Qt.Key_Meta: 'super',
                QtCore.Qt.Key_Return: 'enter',
                QtCore.Qt.Key_Left: 'left',
                QtCore.Qt.Key_Up: 'up',
                QtCore.Qt.Key_Right: 'right',
                QtCore.Qt.Key_Down: 'down',
                QtCore.Qt.Key_Escape: 'escape',
                QtCore.Qt.Key_F1: 'f1',
                QtCore.Qt.Key_F2: 'f2',
                QtCore.Qt.Key_F3: 'f3',
                QtCore.Qt.Key_F4: 'f4',
                QtCore.Qt.Key_F5: 'f5',
                QtCore.Qt.Key_F6: 'f6',
                QtCore.Qt.Key_F7: 'f7',
                QtCore.Qt.Key_F8: 'f8',
                QtCore.Qt.Key_F9: 'f9',
                QtCore.Qt.Key_F10: 'f10',
                QtCore.Qt.Key_F11: 'f11',
                QtCore.Qt.Key_F12: 'f12',
                QtCore.Qt.Key_Home: 'home',
                QtCore.Qt.Key_End: 'end',
                QtCore.Qt.Key_PageUp: 'pageup',
                QtCore.Qt.Key_PageDown: 'pagedown',
                QtCore.Qt.Key_Tab: 'tab',
                QtCore.Qt.Key_Backspace: 'backspace',
                QtCore.Qt.Key_Enter: 'enter',
                QtCore.Qt.Key_Insert: 'insert',
                QtCore.Qt.Key_Delete: 'delete',
                QtCore.Qt.Key_Pause: 'pause',
                QtCore.Qt.Key_SysReq: 'sysreq',
                QtCore.Qt.Key_Clear: 'clear', }

# define which modifier keys are collected on keyboard events.
# elements are (mpl names, Modifier Flag, Qt Key) tuples
SUPER = 0
ALT = 1
CTRL = 2
SHIFT = 3
MODIFIER_KEYS = [('super', QtCore.Qt.MetaModifier, QtCore.Qt.Key_Meta),
                 ('alt', QtCore.Qt.AltModifier, QtCore.Qt.Key_Alt),
                 ('ctrl', QtCore.Qt.ControlModifier, QtCore.Qt.Key_Control),
                 ('shift', QtCore.Qt.ShiftModifier, QtCore.Qt.Key_Shift),
                 ]

if sys.platform == 'darwin':
    # in OSX, the control and super (aka cmd/apple) keys are switched, so
    # switch them back.
    SPECIAL_KEYS.update({QtCore.Qt.Key_Control: 'super',  # cmd/apple key
                         QtCore.Qt.Key_Meta: 'control',
                         })
    MODIFIER_KEYS[0] = ('super', QtCore.Qt.ControlModifier,
                        QtCore.Qt.Key_Control)
    MODIFIER_KEYS[2] = ('ctrl', QtCore.Qt.MetaModifier,
                        QtCore.Qt.Key_Meta)


def fn_name():
    return sys._getframe(1).f_code.co_name

DEBUG = False

cursord = {
    cursors.MOVE: QtCore.Qt.SizeAllCursor,
    cursors.HAND: QtCore.Qt.PointingHandCursor,
    cursors.POINTER: QtCore.Qt.ArrowCursor,
    cursors.SELECT_REGION: QtCore.Qt.CrossCursor,
    }


def draw_if_interactive():
    """
    Is called after every pylab drawing command
    """
    if matplotlib.is_interactive():
        figManager = Gcf.get_active()
        if figManager is not None:
            figManager.canvas.draw_idle()

# make place holder
qApp = None


def _create_qApp():
    """
    Only one qApp can exist at a time, so check before creating one.
    """
    global qApp

    if qApp is None:
        if DEBUG:
            print("Starting up QApplication")
        app = QtWidgets.QApplication.instance()
        if app is None:
            # check for DISPLAY env variable on X11 build of Qt
            if hasattr(QtGui, "QX11Info"):
                display = os.environ.get('DISPLAY')
                if display is None or not re.search(':\d', display):
                    raise RuntimeError('Invalid DISPLAY variable')

            qApp = QtWidgets.QApplication([str(" ")])
            qApp.lastWindowClosed.connect(qApp.quit)
        else:
            qApp = app

    if is_pyqt5():
        qApp.setAttribute(QtCore.Qt.AA_UseHighDpiPixmaps)


class Show(ShowBase):
    def mainloop(self):
        # allow KeyboardInterrupt exceptions to close the plot window.
        signal.signal(signal.SIGINT, signal.SIG_DFL)
        global qApp
        qApp.exec_()

show = Show()


def new_figure_manager(num, *args, **kwargs):
    """
    Create a new figure manager instance
    """
    thisFig = Figure(*args, **kwargs)
    return new_figure_manager_given_figure(num, thisFig)


def new_figure_manager_given_figure(num, figure):
    """
    Create a new figure manager instance for the given figure.
    """
    canvas = FigureCanvasQT(figure)
    manager = FigureManagerQT(canvas, num)
    return manager


class TimerQT(TimerBase):
    '''
    Subclass of :class:`backend_bases.TimerBase` that uses Qt4 timer events.

    Attributes:
    * interval: The time between timer events in milliseconds. Default
        is 1000 ms.
    * single_shot: Boolean flag indicating whether this timer should
        operate as single shot (run once and then stop). Defaults to False.
    * callbacks: 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):
        TimerBase.__init__(self, *args, **kwargs)

        # Create a new timer and connect the timeout() signal to the
        # _on_timer method.
        self._timer = QtCore.QTimer()
        self._timer.timeout.connect(self._on_timer)
        self._timer_set_interval()

    def __del__(self):
        # Probably not necessary in practice, but is good behavior to
        # disconnect
        try:
            TimerBase.__del__(self)
            self._timer.timeout.disconnect(self._on_timer)
        except RuntimeError:
            # Timer C++ object already deleted
            pass

    def _timer_set_single_shot(self):
        self._timer.setSingleShot(self._single)

    def _timer_set_interval(self):
        self._timer.setInterval(self._interval)

    def _timer_start(self):
        self._timer.start()

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


class FigureCanvasQT(QtWidgets.QWidget, FigureCanvasBase):

    # map Qt button codes to MouseEvent's ones:
    buttond = {QtCore.Qt.LeftButton: 1,
               QtCore.Qt.MidButton: 2,
               QtCore.Qt.RightButton: 3,
               # QtCore.Qt.XButton1: None,
               # QtCore.Qt.XButton2: None,
               }

    def __init__(self, figure):
        if DEBUG:
            print('FigureCanvasQt qt5: ', figure)
        _create_qApp()

        # NB: Using super for this call to avoid a TypeError:
        # __init__() takes exactly 2 arguments (1 given) on QWidget
        # PyQt5
        # The need for this change is documented here
        # http://pyqt.sourceforge.net/Docs/PyQt5/pyqt4_differences.html#cooperative-multi-inheritance
        super(FigureCanvasQT, self).__init__(figure=figure)
        self.figure = figure
        self.setMouseTracking(True)
        w, h = self.get_width_height()
        self.resize(w, h)

    @property
    def _dpi_ratio(self):
        # Not available on Qt4 or some older Qt5.
        try:
            return self.devicePixelRatio()
        except AttributeError:
            return 1

    def get_width_height(self):
        w, h = FigureCanvasBase.get_width_height(self)
        return int(w / self._dpi_ratio), int(h / self._dpi_ratio)

    def enterEvent(self, event):
        FigureCanvasBase.enter_notify_event(self, guiEvent=event)

    def leaveEvent(self, event):
        QtWidgets.QApplication.restoreOverrideCursor()
        FigureCanvasBase.leave_notify_event(self, guiEvent=event)

    def mouseEventCoords(self, pos):
        x = pos.x() * self._dpi_ratio
        # flip y so y=0 is bottom of canvas
        y = self.figure.bbox.height - pos.y() * self._dpi_ratio
        return x, y

    def mousePressEvent(self, event):
        x, y = self.mouseEventCoords(event.pos())
        button = self.buttond.get(event.button())
        if button is not None:
            FigureCanvasBase.button_press_event(self, x, y, button,
                                                guiEvent=event)
        if DEBUG:
            print('button pressed:', event.button())

    def mouseDoubleClickEvent(self, event):
        x, y = self.mouseEventCoords(event.pos())
        button = self.buttond.get(event.button())
        if button is not None:
            FigureCanvasBase.button_press_event(self, x, y,
                                                button, dblclick=True,
                                                guiEvent=event)
        if DEBUG:
            print('button doubleclicked:', event.button())

    def mouseMoveEvent(self, event):
        x, y = self.mouseEventCoords(event)
        FigureCanvasBase.motion_notify_event(self, x, y, guiEvent=event)
        # if DEBUG: print('mouse move')

    def mouseReleaseEvent(self, event):
        x, y = self.mouseEventCoords(event)
        button = self.buttond.get(event.button())
        if button is not None:
            FigureCanvasBase.button_release_event(self, x, y, button,
                                                  guiEvent=event)
        if DEBUG:
            print('button released')

    def wheelEvent(self, event):
        x, y = self.mouseEventCoords(event)
        # from QWheelEvent::delta doc
        if event.pixelDelta().x() == 0 and event.pixelDelta().y() == 0:
            steps = event.angleDelta().y() / 120
        else:
            steps = event.pixelDelta().y()

        if steps != 0:
            FigureCanvasBase.scroll_event(self, x, y, steps, guiEvent=event)
            if DEBUG:
                print('scroll event: delta = %i, '
                      'steps = %i ' % (event.delta(), steps))

    def keyPressEvent(self, event):
        key = self._get_key(event)
        if key is None:
            return
        FigureCanvasBase.key_press_event(self, key, guiEvent=event)
        if DEBUG:
            print('key press', key)

    def keyReleaseEvent(self, event):
        key = self._get_key(event)
        if key is None:
            return
        FigureCanvasBase.key_release_event(self, key, guiEvent=event)
        if DEBUG:
            print('key release', key)

    def resizeEvent(self, event):
        w = event.size().width() * self._dpi_ratio
        h = event.size().height() * self._dpi_ratio
        if DEBUG:
            print('resize (%d x %d)' % (w, h))
            print("FigureCanvasQt.resizeEvent(%d, %d)" % (w, h))
        dpival = self.figure.dpi
        winch = w / dpival
        hinch = h / dpival
        self.figure.set_size_inches(winch, hinch, forward=False)
        FigureCanvasBase.resize_event(self)
        self.draw_idle()
        QtWidgets.QWidget.resizeEvent(self, event)

    def sizeHint(self):
        w, h = self.get_width_height()
        return QtCore.QSize(w, h)

    def minumumSizeHint(self):
        return QtCore.QSize(10, 10)

    def _get_key(self, event):
        if event.isAutoRepeat():
            return None

        event_key = event.key()
        event_mods = int(event.modifiers())  # actually a bitmask

        # get names of the pressed modifier keys
        # bit twiddling to pick out modifier keys from event_mods bitmask,
        # if event_key is a MODIFIER, it should not be duplicated in mods
        mods = [name for name, mod_key, qt_key in MODIFIER_KEYS
                if event_key != qt_key and (event_mods & mod_key) == mod_key]
        try:
            # for certain keys (enter, left, backspace, etc) use a word for the
            # key, rather than unicode
            key = SPECIAL_KEYS[event_key]
        except KeyError:
            # unicode defines code points up to 0x0010ffff
            # QT will use Key_Codes larger than that for keyboard keys that are
            # are not unicode characters (like multimedia keys)
            # skip these
            # if you really want them, you should add them to SPECIAL_KEYS
            MAX_UNICODE = 0x10ffff
            if event_key > MAX_UNICODE:
                return None

            key = unichr(event_key)
            # qt delivers capitalized letters.  fix capitalization
            # note that capslock is ignored
            if 'shift' in mods:
                mods.remove('shift')
            else:
                key = key.lower()

        mods.reverse()
        return '+'.join(mods + [key])

    def new_timer(self, *args, **kwargs):
        """
        Creates a new backend-specific subclass of
        :class:`backend_bases.Timer`.  This is useful for getting
        periodic events through the backend's native event
        loop. Implemented only for backends with GUIs.

        optional arguments:

        *interval*
            Timer interval in milliseconds

        *callbacks*
            Sequence of (func, args, kwargs) where func(*args, **kwargs)
            will be executed by the timer every *interval*.

    """
        return TimerQT(*args, **kwargs)

    def flush_events(self):
        global qApp
        qApp.processEvents()

    def start_event_loop(self, timeout):
        FigureCanvasBase.start_event_loop_default(self, timeout)

    start_event_loop.__doc__ = \
                             FigureCanvasBase.start_event_loop_default.__doc__

    def stop_event_loop(self):
        FigureCanvasBase.stop_event_loop_default(self)

    stop_event_loop.__doc__ = FigureCanvasBase.stop_event_loop_default.__doc__


class MainWindow(QtWidgets.QMainWindow):
    closing = QtCore.Signal()

    def closeEvent(self, event):
        self.closing.emit()
        QtWidgets.QMainWindow.closeEvent(self, event)


class FigureManagerQT(FigureManagerBase):
    """
    Public attributes

    canvas      : The FigureCanvas instance
    num         : The Figure number
    toolbar     : The qt.QToolBar
    window      : The qt.QMainWindow
    """

    def __init__(self, canvas, num):
        if DEBUG:
            print('FigureManagerQT.%s' % fn_name())
        FigureManagerBase.__init__(self, canvas, num)
        self.canvas = canvas
        self.window = MainWindow()
        self.window.closing.connect(canvas.close_event)
        self.window.closing.connect(self._widgetclosed)

        self.window.setWindowTitle("Figure %d" % num)
        image = os.path.join(matplotlib.rcParams['datapath'],
                             'images', 'matplotlib.png')
        self.window.setWindowIcon(QtGui.QIcon(image))

        # Give the keyboard focus to the figure instead of the
        # manager; StrongFocus accepts both tab and click to focus and
        # will enable the canvas to process event w/o clicking.
        # ClickFocus only takes the focus is the window has been
        # clicked
        # on. http://qt-project.org/doc/qt-4.8/qt.html#FocusPolicy-enum or
        # http://doc.qt.digia.com/qt/qt.html#FocusPolicy-enum
        self.canvas.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.canvas.setFocus()

        self.window._destroying = False

        # add text label to status bar
        self.statusbar_label = QtWidgets.QLabel()
        self.window.statusBar().addWidget(self.statusbar_label)

        self.toolbar = self._get_toolbar(self.canvas, self.window)
        if self.toolbar is not None:
            self.window.addToolBar(self.toolbar)
            self.toolbar.message.connect(self.statusbar_label.setText)
            tbs_height = self.toolbar.sizeHint().height()
        else:
            tbs_height = 0

        # resize the main window so it will display the canvas with the
        # requested size:
        cs = canvas.sizeHint()
        sbs = self.window.statusBar().sizeHint()
        self._status_and_tool_height = tbs_height + sbs.height()
        height = cs.height() + self._status_and_tool_height
        self.window.resize(cs.width(), height)

        self.window.setCentralWidget(self.canvas)

        if matplotlib.is_interactive():
            self.window.show()
            self.canvas.draw_idle()

        def notify_axes_change(fig):
            # This will be called whenever the current axes is changed
            if self.toolbar is not None:
                self.toolbar.update()
        self.canvas.figure.add_axobserver(notify_axes_change)
        self.window.raise_()

    def full_screen_toggle(self):
        if self.window.isFullScreen():
            self.window.showNormal()
        else:
            self.window.showFullScreen()

    def _widgetclosed(self):
        if self.window._destroying:
            return
        self.window._destroying = True
        try:
            Gcf.destroy(self.num)
        except AttributeError:
            pass
            # It seems that when the python session is killed,
            # Gcf can get destroyed before the Gcf.destroy
            # line is run, leading to a useless AttributeError.

    def _get_toolbar(self, canvas, parent):
        # must be inited after the window, drawingArea and figure
        # attrs are set
        if matplotlib.rcParams['toolbar'] == 'toolbar2':
            toolbar = NavigationToolbar2QT(canvas, parent, False)
        else:
            toolbar = None
        return toolbar

    def resize(self, width, height):
        'set the canvas size in pixels'
        self.window.resize(width, height + self._status_and_tool_height)

    def show(self):
        self.window.show()

    def destroy(self, *args):
        # check for qApp first, as PySide deletes it in its atexit handler
        if QtWidgets.QApplication.instance() is None:
            return
        if self.window._destroying:
            return
        self.window._destroying = True
        self.window.destroyed.connect(self._widgetclosed)

        if self.toolbar:
            self.toolbar.destroy()
        if DEBUG:
            print("destroy figure manager")
        self.window.close()

    def get_window_title(self):
        return six.text_type(self.window.windowTitle())

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


class NavigationToolbar2QT(NavigationToolbar2, QtWidgets.QToolBar):
    message = QtCore.Signal(str)

    def __init__(self, canvas, parent, coordinates=True):
        """ coordinates: should we show the coordinates on the right? """
        self.canvas = canvas
        self.parent = parent
        self.coordinates = coordinates
        self._actions = {}
        """A mapping of toolitem method names to their QActions"""

        QtWidgets.QToolBar.__init__(self, parent)
        NavigationToolbar2.__init__(self, canvas)

    def _icon(self, name):
        if is_pyqt5():
            name = name.replace('.png', '_large.png')
        return QtGui.QIcon(os.path.join(self.basedir, name))

    def _init_toolbar(self):
        self.basedir = os.path.join(matplotlib.rcParams['datapath'], 'images')

        for text, tooltip_text, image_file, callback in self.toolitems:
            if text is None:
                self.addSeparator()
            else:
                a = self.addAction(self._icon(image_file + '.png'),
                                         text, getattr(self, callback))
                self._actions[callback] = a
                if callback in ['zoom', 'pan']:
                    a.setCheckable(True)
                if tooltip_text is not None:
                    a.setToolTip(tooltip_text)
                if text == 'Subplots':
                    a = self.addAction(self._icon("qt4_editor_options.png"),
                                       'Customize', self.edit_parameters)
                    a.setToolTip('Edit axis, curve and image parameters')

        self.buttons = {}

        # Add the x,y location widget at the right side of the toolbar
        # The stretch factor is 1 which means any resizing of the toolbar
        # will resize this label instead of the buttons.
        if self.coordinates:
            self.locLabel = QtWidgets.QLabel("", self)
            self.locLabel.setAlignment(
                    QtCore.Qt.AlignRight | QtCore.Qt.AlignTop)
            self.locLabel.setSizePolicy(
                QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Expanding,
                                  QtWidgets.QSizePolicy.Ignored))
            labelAction = self.addWidget(self.locLabel)
            labelAction.setVisible(True)

        # reference holder for subplots_adjust window
        self.adj_window = None

        # Esthetic adjustments - we need to set these explicitly in PyQt5
        # otherwise the layout looks different - but we don't want to set it if
        # not using HiDPI icons otherwise they look worse than before.
        if is_pyqt5():
            self.setIconSize(QtCore.QSize(24, 24))
            self.layout().setSpacing(12)

    if is_pyqt5():
        # For some reason, self.setMinimumHeight doesn't seem to carry over to
        # the actual sizeHint, so override it instead in order to make the
        # aesthetic adjustments noted above.
        def sizeHint(self):
            size = super(NavigationToolbar2QT, self).sizeHint()
            size.setHeight(max(48, size.height()))
            return size

    def edit_parameters(self):
        allaxes = self.canvas.figure.get_axes()
        if not allaxes:
            QtWidgets.QMessageBox.warning(
                self.parent, "Error", "There are no axes to edit.")
            return
        if len(allaxes) == 1:
            axes = allaxes[0]
        else:
            titles = []
            for axes in allaxes:
                name = (axes.get_title() or
                        " - ".join(filter(None, [axes.get_xlabel(),
                                                 axes.get_ylabel()])) or
                        "<anonymous {} (id: {:#x})>".format(
                            type(axes).__name__, id(axes)))
                titles.append(name)
            item, ok = QtWidgets.QInputDialog.getItem(
                self.parent, 'Customize', 'Select axes:', titles, 0, False)
            if ok:
                axes = allaxes[titles.index(six.text_type(item))]
            else:
                return

        figureoptions.figure_edit(axes, self)

    def _update_buttons_checked(self):
        # sync button checkstates to match active mode
        self._actions['pan'].setChecked(self._active == 'PAN')
        self._actions['zoom'].setChecked(self._active == 'ZOOM')

    def pan(self, *args):
        super(NavigationToolbar2QT, self).pan(*args)
        self._update_buttons_checked()

    def zoom(self, *args):
        super(NavigationToolbar2QT, self).zoom(*args)
        self._update_buttons_checked()

    def dynamic_update(self):
        self.canvas.draw_idle()

    def set_message(self, s):
        self.message.emit(s)
        if self.coordinates:
            self.locLabel.setText(s)

    def set_cursor(self, cursor):
        if DEBUG:
            print('Set cursor', cursor)
        self.canvas.setCursor(cursord[cursor])

    def draw_rubberband(self, event, x0, y0, x1, y1):
        height = self.canvas.figure.bbox.height
        y1 = height - y1
        y0 = height - y0

        w = abs(x1 - x0)
        h = abs(y1 - y0)

        rect = [int(val)for val in (min(x0, x1), min(y0, y1), w, h)]
        self.canvas.drawRectangle(rect)

    def remove_rubberband(self):
        self.canvas.drawRectangle(None)

    def configure_subplots(self):
        image = os.path.join(matplotlib.rcParams['datapath'],
                             'images', 'matplotlib.png')
        dia = SubplotToolQt(self.canvas.figure, self.parent)
        dia.setWindowIcon(QtGui.QIcon(image))
        dia.exec_()

    def save_figure(self, *args):
        filetypes = self.canvas.get_supported_filetypes_grouped()
        sorted_filetypes = list(six.iteritems(filetypes))
        sorted_filetypes.sort()
        default_filetype = self.canvas.get_default_filetype()

        startpath = matplotlib.rcParams.get('savefig.directory', '')
        startpath = os.path.expanduser(startpath)
        start = os.path.join(startpath, self.canvas.get_default_filename())
        filters = []
        selectedFilter = None
        for name, exts in sorted_filetypes:
            exts_list = " ".join(['*.%s' % ext for ext in exts])
            filter = '%s (%s)' % (name, exts_list)
            if default_filetype in exts:
                selectedFilter = filter
            filters.append(filter)
        filters = ';;'.join(filters)

        fname, filter = _getSaveFileName(self.parent,
                                         "Choose a filename to save to",
                                 start, filters, selectedFilter)
        if fname:
            if startpath == '':
                # explicitly missing key or empty str signals to use cwd
                matplotlib.rcParams['savefig.directory'] = startpath
            else:
                # save dir for next time
                savefig_dir = os.path.dirname(six.text_type(fname))
                matplotlib.rcParams['savefig.directory'] = savefig_dir
            try:
                self.canvas.print_figure(six.text_type(fname))
            except Exception as e:
                QtWidgets.QMessageBox.critical(
                    self, "Error saving file", six.text_type(e),
                    QtWidgets.QMessageBox.Ok, QtWidgets.QMessageBox.NoButton)


class SubplotToolQt(SubplotTool, UiSubplotTool):
    def __init__(self, targetfig, parent):
        UiSubplotTool.__init__(self, None)

        self.targetfig = targetfig
        self.parent = parent
        self.donebutton.clicked.connect(self.close)
        self.resetbutton.clicked.connect(self.reset)
        self.tightlayout.clicked.connect(self.functight)

        # constraints
        self.sliderleft.valueChanged.connect(self.sliderright.setMinimum)
        self.sliderright.valueChanged.connect(self.sliderleft.setMaximum)
        self.sliderbottom.valueChanged.connect(self.slidertop.setMinimum)
        self.slidertop.valueChanged.connect(self.sliderbottom.setMaximum)

        self.defaults = {}
        for attr in ('left', 'bottom', 'right', 'top', 'wspace', 'hspace', ):
            val = getattr(self.targetfig.subplotpars, attr)
            self.defaults[attr] = val
            slider = getattr(self, 'slider' + attr)
            txt = getattr(self, attr + 'value')
            slider.setMinimum(0)
            slider.setMaximum(1000)
            slider.setSingleStep(5)
            # do this before hooking up the callbacks
            slider.setSliderPosition(int(val * 1000))
            txt.setText("%.2f" % val)
            slider.valueChanged.connect(getattr(self, 'func' + attr))
        self._setSliderPositions()

    def _setSliderPositions(self):
        for attr in ('left', 'bottom', 'right', 'top', 'wspace', 'hspace', ):
            slider = getattr(self, 'slider' + attr)
            slider.setSliderPosition(int(self.defaults[attr] * 1000))

    def funcleft(self, val):
        if val == self.sliderright.value():
            val -= 1
        val /= 1000.
        self.targetfig.subplots_adjust(left=val)
        self.leftvalue.setText("%.2f" % val)
        if self.drawon:
            self.targetfig.canvas.draw_idle()

    def funcright(self, val):
        if val == self.sliderleft.value():
            val += 1
        val /= 1000.
        self.targetfig.subplots_adjust(right=val)
        self.rightvalue.setText("%.2f" % val)
        if self.drawon:
            self.targetfig.canvas.draw_idle()

    def funcbottom(self, val):
        if val == self.slidertop.value():
            val -= 1
        val /= 1000.
        self.targetfig.subplots_adjust(bottom=val)
        self.bottomvalue.setText("%.2f" % val)
        if self.drawon:
            self.targetfig.canvas.draw_idle()

    def functop(self, val):
        if val == self.sliderbottom.value():
            val += 1
        val /= 1000.
        self.targetfig.subplots_adjust(top=val)
        self.topvalue.setText("%.2f" % val)
        if self.drawon:
            self.targetfig.canvas.draw_idle()

    def funcwspace(self, val):
        val /= 1000.
        self.targetfig.subplots_adjust(wspace=val)
        self.wspacevalue.setText("%.2f" % val)
        if self.drawon:
            self.targetfig.canvas.draw_idle()

    def funchspace(self, val):
        val /= 1000.
        self.targetfig.subplots_adjust(hspace=val)
        self.hspacevalue.setText("%.2f" % val)
        if self.drawon:
            self.targetfig.canvas.draw_idle()

    def functight(self):
        self.targetfig.tight_layout()
        self._setSliderPositions()
        self.targetfig.canvas.draw_idle()

    def reset(self):
        self.targetfig.subplots_adjust(**self.defaults)
        self._setSliderPositions()
        self.targetfig.canvas.draw_idle()


def error_msg_qt(msg, parent=None):
    if not is_string_like(msg):
        msg = ','.join(map(str, msg))

    QtWidgets.QMessageBox.warning(None, "Matplotlib",
                                  msg, QtGui.QMessageBox.Ok)


def exception_handler(type, value, tb):
    """Handle uncaught exceptions
    It does not catch SystemExit
    """
    msg = ''
    # get the filename attribute if available (for IOError)
    if hasattr(value, 'filename') and value.filename is not None:
        msg = value.filename + ': '
    if hasattr(value, 'strerror') and value.strerror is not None:
        msg += value.strerror
    else:
        msg += six.text_type(value)

    if len(msg):
        error_msg_qt(msg)

FigureCanvas = FigureCanvasQT
FigureManager = FigureManagerQT