canvas.py

# Copyright (c) <2015-Present> Tzutalin
# Copyright (C) 2013  MIT, Computer Science and Artificial Intelligence Laboratory. Bryan Russell, Antonio Torralba,
# William T. Freeman. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
# associated documentation files (the "Software"), to deal in the Software without restriction, including without
# limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
# Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
# The above copyright notice and this permission notice shall be included in all copies or substantial portions of
# the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
# NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
# SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
# CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

import copy

from PyQt5.QtCore import Qt, pyqtSignal, QPointF, QPoint
from PyQt5.QtGui import QPainter, QBrush, QColor, QPixmap
from PyQt5.QtWidgets import QWidget, QMenu, QApplication
from libs.shape import Shape
from libs.utils import distance

CURSOR_DEFAULT = Qt.ArrowCursor
CURSOR_POINT = Qt.PointingHandCursor
CURSOR_DRAW = Qt.CrossCursor
CURSOR_MOVE = Qt.ClosedHandCursor
CURSOR_GRAB = Qt.OpenHandCursor


class Canvas(QWidget):
    zoomRequest = pyqtSignal(int)
    scrollRequest = pyqtSignal(int, int)
    newShape = pyqtSignal()
    # selectionChanged = pyqtSignal(bool)
    selectionChanged = pyqtSignal(list)
    shapeMoved = pyqtSignal()
    drawingPolygon = pyqtSignal(bool)

    CREATE, EDIT = list(range(2))
    _fill_drawing = False # draw shadows

    epsilon = 5.0

    def __init__(self, *args, **kwargs):
        super(Canvas, self).__init__(*args, **kwargs)
        # Initialise local state.
        self.mode = self.EDIT
        self.shapes = []
        self.shapesBackups = []
        self.current = None
        self.selectedShapes = []
        self.selectedShape = None  # save the selected shape here
        self.selectedShapesCopy = []
        self.drawingLineColor = QColor(0, 0, 255)
        self.drawingRectColor = QColor(0, 0, 255)
        self.line = Shape(line_color=self.drawingLineColor)
        self.prevPoint = QPointF()
        self.offsets = QPointF(), QPointF()
        self.scale = 1.0
        self.pixmap = QPixmap()
        self.visible = {}
        self._hideBackround = False
        self.hideBackround = False
        self.hShape = None
        self.hVertex = None
        self._painter = QPainter()
        self._cursor = CURSOR_DEFAULT
        # Menus:
        self.menus = (QMenu(), QMenu())
        # Set widget options.
        self.setMouseTracking(True)
        self.setFocusPolicy(Qt.WheelFocus)
        self.verified = False
        self.drawSquare = False
        self.fourpoint = True # ADD
        self.pointnum = 0
        self.movingShape = False
        self.selectCountShape = False

        #initialisation for panning
        self.pan_initial_pos = QPoint()

        #lockedshapes related 
        self.lockedShapes = []
        self.isInTheSameImage = False

    def setDrawingColor(self, qColor):
        self.drawingLineColor = qColor
        self.drawingRectColor = qColor

    def enterEvent(self, ev):
        self.overrideCursor(self._cursor)

    def leaveEvent(self, ev):
        self.restoreCursor()

    def focusOutEvent(self, ev):
        self.restoreCursor()

    def isVisible(self, shape):
        return self.visible.get(shape, True)

    def drawing(self):
        return self.mode == self.CREATE

    def editing(self):
        return self.mode == self.EDIT

    def setEditing(self, value=True):
        self.mode = self.EDIT if value else self.CREATE
        if not value:  # Create
            self.unHighlight()
            self.deSelectShape()
        self.prevPoint = QPointF()
        self.repaint()

    def unHighlight(self):
        if self.hShape:
            self.hShape.highlightClear()
        self.hVertex = self.hShape = None

    def selectedVertex(self):
        return self.hVertex is not None

    def mouseMoveEvent(self, ev):
        """Update line with last point and current coordinates."""
        pos = self.transformPos(ev.pos())

        # Update coordinates in status bar if image is opened
        window = self.parent().window()
        if window.filePath is not None:
            self.parent().window().labelCoordinates.setText(
                'X: %d; Y: %d' % (pos.x(), pos.y()))

        # Polygon drawing.
        if self.drawing():
            self.overrideCursor(CURSOR_DRAW) # ?
            if self.current:
                # Display annotation width and height while drawing
                currentWidth = abs(self.current[0].x() - pos.x())
                currentHeight = abs(self.current[0].y() - pos.y())
                self.parent().window().labelCoordinates.setText(
                        'Width: %d, Height: %d / X: %d; Y: %d' % (currentWidth, currentHeight, pos.x(), pos.y()))

                color = self.drawingLineColor
                if self.outOfPixmap(pos):
                    # Don't allow the user to draw outside the pixmap.
                    # Clip the coordinates to 0 or max,
                    # if they are outside the range [0, max]
                    size = self.pixmap.size()
                    clipped_x = min(max(0, pos.x()), size.width())
                    clipped_y = min(max(0, pos.y()), size.height())
                    pos = QPointF(clipped_x, clipped_y)

                elif len(self.current) > 1 and self.closeEnough(pos, self.current[0]):
                    # Attract line to starting point and colorise to alert the
                    # user:
                    pos = self.current[0]
                    color = self.current.line_color
                    self.overrideCursor(CURSOR_POINT)
                    self.current.highlightVertex(0, Shape.NEAR_VERTEX)

                if self.drawSquare:
                    self.line.points = [self.current[0], pos]
                    self.line.close()

                elif self.fourpoint:
                    self.line[0] = self.current[-1]
                    self.line[1] = pos

                else:
                    self.line[1] = pos # pos is the mouse's current position

                self.line.line_color = color
                self.prevPoint = QPointF() # ？
                self.current.highlightClear()
            else:
                self.prevPoint = pos
            self.repaint()
            return

        # Polygon copy moving.
        if Qt.RightButton & ev.buttons():
            if self.selectedShapesCopy and self.prevPoint:
                self.overrideCursor(CURSOR_MOVE)
                self.boundedMoveShape(self.selectedShapesCopy, pos)
                self.repaint()
            elif self.selectedShapes:
                self.selectedShapesCopy = [
                    s.copy() for s in self.selectedShapes
                ]
                self.repaint()
            return

        # Polygon/Vertex moving.
        if Qt.LeftButton & ev.buttons():
            if self.selectedVertex():
                self.boundedMoveVertex(pos)
                self.shapeMoved.emit()
                self.repaint()
                self.movingShape = True
            elif self.selectedShapes and self.prevPoint:
                self.overrideCursor(CURSOR_MOVE)
                self.boundedMoveShape(self.selectedShapes, pos)
                self.shapeMoved.emit()
                self.repaint()
                self.movingShape = True
            else:
                #pan
                delta_x = pos.x() - self.pan_initial_pos.x()
                delta_y = pos.y() - self.pan_initial_pos.y()
                self.scrollRequest.emit(delta_x, Qt.Horizontal)
                self.scrollRequest.emit(delta_y, Qt.Vertical)
                self.update()
            return

        # Just hovering over the canvas, 2 posibilities:
        # - Highlight shapes
        # - Highlight vertex
        # Update shape/vertex fill and tooltip value accordingly.
        self.setToolTip("Image")
        for shape in reversed([s for s in self.shapes if self.isVisible(s)]):
            # Look for a nearby vertex to highlight. If that fails,
            # check if we happen to be inside a shape.
            index = shape.nearestVertex(pos, self.epsilon)
            if index is not None:
                if self.selectedVertex():
                    self.hShape.highlightClear()
                self.hVertex, self.hShape = index, shape
                shape.highlightVertex(index, shape.MOVE_VERTEX)
                self.overrideCursor(CURSOR_POINT)
                self.setToolTip("Click & drag to move point")
                self.setStatusTip(self.toolTip())
                self.update()
                break
            elif shape.containsPoint(pos):
                if self.selectedVertex():
                    self.hShape.highlightClear()
                self.hVertex, self.hShape = None, shape
                self.setToolTip(
                    "Click & drag to move shape '%s'" % shape.label)
                self.setStatusTip(self.toolTip())
                self.overrideCursor(CURSOR_GRAB)
                self.update()
                break
        else:  # Nothing found, clear highlights, reset state.
            if self.hShape:
                self.hShape.highlightClear()
                self.update()
            self.hVertex, self.hShape = None, None
            self.overrideCursor(CURSOR_DEFAULT)

    def mousePressEvent(self, ev):
        pos = self.transformPos(ev.pos())
        if ev.button() == Qt.LeftButton:
            if self.drawing():
                # self.handleDrawing(pos) # OLD
                if self.current:
                    if self.fourpoint: # ADD IF
                        # Add point to existing shape.
                        # print('Adding points in mousePressEvent is ', self.line[1])
                        self.current.addPoint(self.line[1])
                        self.line[0] = self.current[-1]
                        if self.current.isClosed():
                            # print('1111')
                            self.finalise()
                    elif self.drawSquare:
                        assert len(self.current.points) == 1
                        self.current.points = self.line.points
                        self.finalise()
                elif not self.outOfPixmap(pos):
                    # Create new shape.
                    self.current = Shape()
                    self.current.addPoint(pos)
                    self.line.points = [pos, pos]
                    self.setHiding()
                    self.drawingPolygon.emit(True)
                    self.update()

            else:
                group_mode = int(ev.modifiers()) == Qt.ControlModifier
                self.selectShapePoint(pos, multiple_selection_mode=group_mode)
                self.prevPoint = pos
                self.pan_initial_pos = pos

        elif ev.button() == Qt.RightButton and self.editing():
            group_mode = int(ev.modifiers()) == Qt.ControlModifier
            self.selectShapePoint(pos, multiple_selection_mode=group_mode)
            self.prevPoint = pos
        self.update()

    def mouseReleaseEvent(self, ev):
        if ev.button() == Qt.RightButton:
            menu = self.menus[bool(self.selectedShapesCopy)]
            self.restoreCursor()
            if not menu.exec_(self.mapToGlobal(ev.pos()))\
               and self.selectedShapesCopy:
                # Cancel the move by deleting the shadow copy.
                # self.selectedShapeCopy = None
                self.selectedShapesCopy = []
                self.repaint()

        elif ev.button() == Qt.LeftButton and self.selectedShapes:
            if self.selectedVertex():
                self.overrideCursor(CURSOR_POINT)
            else:
                self.overrideCursor(CURSOR_GRAB)

        elif ev.button() == Qt.LeftButton and not self.fourpoint:
            pos = self.transformPos(ev.pos())
            if self.drawing():
                self.handleDrawing(pos)
            else:
                #pan
                QApplication.restoreOverrideCursor() # ?

        if self.movingShape and self.hShape:
            if self.hShape in self.shapes:
                index = self.shapes.index(self.hShape)
                if (
                    self.shapesBackups[-1][index].points
                    != self.shapes[index].points
                ):
                    self.storeShapes()
                    self.shapeMoved.emit() # connect to updateBoxlist in PPOCRLabel.py

                self.movingShape = False

    def endMove(self, copy=False):
        assert self.selectedShapes and self.selectedShapesCopy
        assert len(self.selectedShapesCopy) == len(self.selectedShapes)
        if copy:
            for i, shape in enumerate(self.selectedShapesCopy):
                shape.idx = len(self.shapes) # add current box index
                self.shapes.append(shape)
                self.selectedShapes[i].selected = False
                self.selectedShapes[i] = shape
        else:
            for i, shape in enumerate(self.selectedShapesCopy):
                self.selectedShapes[i].points = shape.points
        self.selectedShapesCopy = []
        self.repaint()
        self.storeShapes()
        return True

    def hideBackroundShapes(self, value):
        self.hideBackround = value
        if self.selectedShapes:
            # Only hide other shapes if there is a current selection.
            # Otherwise the user will not be able to select a shape.
            self.setHiding(True)
            self.repaint()

    def handleDrawing(self, pos):
        if self.current and self.current.reachMaxPoints() is False:
            if self.fourpoint:
                targetPos = self.line[self.pointnum]
                self.current.addPoint(targetPos)
                print('current points in handleDrawing is ', self.line[self.pointnum])
                self.update()
                if self.pointnum == 3:
                    self.finalise()

            else:
                initPos = self.current[0]
                print('initPos', self.current[0])
                minX = initPos.x()
                minY = initPos.y()
                targetPos = self.line[1]
                maxX = targetPos.x()
                maxY = targetPos.y()
                self.current.addPoint(QPointF(maxX, minY))
                self.current.addPoint(targetPos)
                self.current.addPoint(QPointF(minX, maxY))
                self.finalise()

        elif not self.outOfPixmap(pos):
            print('release')
            self.current = Shape()
            self.current.addPoint(pos)
            self.line.points = [pos, pos]
            self.setHiding()
            self.drawingPolygon.emit(True)
            self.update()

    def setHiding(self, enable=True):
        self._hideBackround = self.hideBackround if enable else False

    def canCloseShape(self):
        return self.drawing() and self.current and len(self.current) > 2

    def mouseDoubleClickEvent(self, ev):
        # We need at least 4 points here, since the mousePress handler
        # adds an extra one before this handler is called.
        if self.canCloseShape() and len(self.current) > 3:
            if not self.fourpoint:
                self.current.popPoint()
            self.finalise()

    def selectShapes(self, shapes):
        for s in shapes: s.seleted = True
        self.setHiding()
        self.selectionChanged.emit(shapes)
        self.update()

    def selectShapePoint(self, point, multiple_selection_mode):
        """Select the first shape created which contains this point."""
        if self.selectedVertex():  # A vertex is marked for selection.
            index, shape = self.hVertex, self.hShape
            shape.highlightVertex(index, shape.MOVE_VERTEX)
            return self.hVertex
        else:
            for shape in reversed(self.shapes):
                if self.isVisible(shape) and shape.containsPoint(point):
                    self.calculateOffsets(shape, point)
                    self.setHiding()
                    if multiple_selection_mode:
                        if shape not in self.selectedShapes: # list
                            self.selectionChanged.emit(
                                self.selectedShapes + [shape]
                            )
                    else:
                        self.selectionChanged.emit([shape])
                    return
        self.deSelectShape()

    def calculateOffsets(self, shape, point):
        rect = shape.boundingRect()
        x1 = rect.x() - point.x()
        y1 = rect.y() - point.y()
        x2 = (rect.x() + rect.width()) - point.x()
        y2 = (rect.y() + rect.height()) - point.y()
        self.offsets = QPointF(x1, y1), QPointF(x2, y2)

    def snapPointToCanvas(self, x, y):
        """
        Moves a point x,y to within the boundaries of the canvas.
        :return: (x,y,snapped) where snapped is True if x or y were changed, False if not.
        """
        if x < 0 or x > self.pixmap.width() or y < 0 or y > self.pixmap.height():
            x = max(x, 0)
            y = max(y, 0)
            x = min(x, self.pixmap.width())
            y = min(y, self.pixmap.height())
            return x, y, True

        return x, y, False

    def boundedMoveVertex(self, pos):
        index, shape = self.hVertex, self.hShape
        point = shape[index]
        if self.outOfPixmap(pos):
            size = self.pixmap.size()
            clipped_x = min(max(0, pos.x()), size.width())
            clipped_y = min(max(0, pos.y()), size.height())
            pos = QPointF(clipped_x, clipped_y)

        if self.drawSquare:
            opposite_point_index = (index + 2) % 4
            opposite_point = shape[opposite_point_index]

            min_size = min(abs(pos.x() - opposite_point.x()), abs(pos.y() - opposite_point.y()))
            directionX = -1 if pos.x() - opposite_point.x() < 0 else 1
            directionY = -1 if pos.y() - opposite_point.y() < 0 else 1
            shiftPos = QPointF(opposite_point.x() + directionX * min_size - point.x(),
                               opposite_point.y() + directionY * min_size - point.y())
        else:
            shiftPos = pos - point

        if [shape[0].x(), shape[0].y(), shape[2].x(), shape[2].y()] \
                == [shape[3].x(),shape[1].y(),shape[1].x(),shape[3].y()]:
            shape.moveVertexBy(index, shiftPos)
            lindex = (index + 1) % 4
            rindex = (index + 3) % 4
            lshift = None
            rshift = None
            if index % 2 == 0:
                rshift = QPointF(shiftPos.x(), 0)
                lshift = QPointF(0, shiftPos.y())
            else:
                lshift = QPointF(shiftPos.x(), 0)
                rshift = QPointF(0, shiftPos.y())
            shape.moveVertexBy(rindex, rshift)
            shape.moveVertexBy(lindex, lshift)

        else:
            shape.moveVertexBy(index, shiftPos)

    def boundedMoveShape(self, shapes, pos):
        if type(shapes).__name__ != 'list': shapes = [shapes]
        if self.outOfPixmap(pos):
            return False  # No need to move
        o1 = pos + self.offsets[0]
        if self.outOfPixmap(o1):
            pos -= QPointF(min(0, o1.x()), min(0, o1.y()))
        o2 = pos + self.offsets[1]
        if self.outOfPixmap(o2):
            pos += QPointF(min(0, self.pixmap.width() - o2.x()),
                           min(0, self.pixmap.height() - o2.y()))
        # The next line tracks the new position of the cursor
        # relative to the shape, but also results in making it
        # a bit "shaky" when nearing the border and allows it to
        # go outside of the shape's area for some reason. XXX
        #self.calculateOffsets(self.selectedShape, pos)
        dp = pos - self.prevPoint
        if dp:
            for shape in shapes:
                shape.moveBy(dp)
                shape.close()
            self.prevPoint = pos
            return True
        return False

    def deSelectShape(self):
        if self.selectedShapes:
            for shape in self.selectedShapes: shape.selected=False
            self.setHiding(False)
            self.selectionChanged.emit([])
            self.update()

    def deleteSelected(self):
        deleted_shapes = []
        if self.selectedShapes:
            for shape in self.selectedShapes:
                self.shapes.remove(shape)
                deleted_shapes.append(shape)
            self.storeShapes()
            self.selectedShapes = []
            self.update()

        self.updateShapeIndex()

        return deleted_shapes

    def storeShapes(self):
        shapesBackup = []
        for shape in self.shapes:
            shapesBackup.append(shape.copy())
        if len(self.shapesBackups) >= 10:
            self.shapesBackups = self.shapesBackups[-9:]
        self.shapesBackups.append(shapesBackup)

    def copySelectedShape(self):
        if self.selectedShapes:
            self.selectedShapesCopy = [s.copy() for s in self.selectedShapes]
            self.boundedShiftShapes(self.selectedShapesCopy)
            self.endMove(copy=True)
        return self.selectedShapes

    def boundedShiftShapes(self, shapes):
        # Try to move in one direction, and if it fails in another.
        # Give up if both fail.
        for shape in shapes:
            point = shape[0]
            offset = QPointF(5.0, 5.0)
            self.calculateOffsets(shape, point)
            self.prevPoint = point
            if not self.boundedMoveShape(shape, point - offset):
                self.boundedMoveShape(shape, point + offset)

    def paintEvent(self, event):
        if not self.pixmap:
            return super(Canvas, self).paintEvent(event)

        p = self._painter
        p.begin(self)
        p.setRenderHint(QPainter.Antialiasing)
        p.setRenderHint(QPainter.HighQualityAntialiasing)
        p.setRenderHint(QPainter.SmoothPixmapTransform)

        p.scale(self.scale, self.scale)
        p.translate(self.offsetToCenter())

        p.drawPixmap(0, 0, self.pixmap)
        Shape.scale = self.scale
        for shape in self.shapes:
            if (shape.selected or not self._hideBackround) and self.isVisible(shape):
                shape.fill = shape.selected or shape == self.hShape
                shape.paint(p)
        if self.current:
            self.current.paint(p)
            self.line.paint(p)
        if self.selectedShapesCopy:
            for s in self.selectedShapesCopy:
                s.paint(p)

        # Paint rect
        if self.current is not None and len(self.line) == 2 and not self.fourpoint:
            # print('Drawing rect')
            leftTop = self.line[0]
            rightBottom = self.line[1]
            rectWidth = rightBottom.x() - leftTop.x()
            rectHeight = rightBottom.y() - leftTop.y()
            p.setPen(self.drawingRectColor)
            brush = QBrush(Qt.BDiagPattern)
            p.setBrush(brush)
            p.drawRect(leftTop.x(), leftTop.y(), rectWidth, rectHeight)


        # ADD：
        if (
                self.fillDrawing()
                and self.fourpoint
                and self.current is not None
                and len(self.current.points) >= 2
        ):
            print('paint event')
            drawing_shape = self.current.copy()
            drawing_shape.addPoint(self.line[1])
            drawing_shape.fill = True
            drawing_shape.paint(p)

        if self.drawing() and not self.prevPoint.isNull() and not self.outOfPixmap(self.prevPoint):
            p.setPen(QColor(0, 0, 0))
            p.drawLine(self.prevPoint.x(), 0, self.prevPoint.x(), self.pixmap.height())
            p.drawLine(0, self.prevPoint.y(), self.pixmap.width(), self.prevPoint.y())

        self.setAutoFillBackground(True)
        if self.verified:
            pal = self.palette()
            pal.setColor(self.backgroundRole(), QColor(184, 239, 38, 128))
            self.setPalette(pal)
        else:
            pal = self.palette()
            pal.setColor(self.backgroundRole(), QColor(232, 232, 232, 255))
            self.setPalette(pal)

        # adaptive BBOX label & index font size
        if self.pixmap:
            h, w = self.pixmap.size().height(), self.pixmap.size().width()
            fontszie = int(max(h, w) / 96)
            for s in self.shapes:
                s.fontsize = fontszie
        
        p.end()

    def fillDrawing(self):
        return self._fill_drawing

    def transformPos(self, point):
        """Convert from widget-logical coordinates to painter-logical coordinates."""
        return point / self.scale - self.offsetToCenter()

    def offsetToCenter(self):
        s = self.scale
        area = super(Canvas, self).size()
        w, h = self.pixmap.width() * s, self.pixmap.height() * s
        aw, ah = area.width(), area.height()
        x = (aw - w) / (2 * s) if aw > w else 0
        y = (ah - h) / (2 * s) if ah > h else 0
        return QPointF(x, y)

    def outOfPixmap(self, p):
        w, h = self.pixmap.width(), self.pixmap.height()
        return not (0 <= p.x() <= w and 0 <= p.y() <= h)

    def finalise(self):
        assert self.current
        if self.current.points[0] == self.current.points[-1]:
            # print('finalse')
            self.current = None
            self.drawingPolygon.emit(False)
            self.update()
            return

        self.current.close()
        self.current.idx = len(self.shapes) # add current box index
        self.shapes.append(self.current) 
        self.current = None
        self.setHiding(False)
        self.newShape.emit()
        self.update()

    def closeEnough(self, p1, p2):
        #d = distance(p1 - p2)
        #m = (p1-p2).manhattanLength()
        # print "d %.2f, m %d, %.2f" % (d, m, d - m)
        return distance(p1 - p2) < self.epsilon

    # These two, along with a call to adjustSize are required for the
    # scroll area.
    def sizeHint(self):
        return self.minimumSizeHint()

    def minimumSizeHint(self):
        if self.pixmap:
            return self.scale * self.pixmap.size()
        return super(Canvas, self).minimumSizeHint()

    def wheelEvent(self, ev):
        qt_version = 4 if hasattr(ev, "delta") else 5
        if qt_version == 4:
            if ev.orientation() == Qt.Vertical:
                v_delta = ev.delta()
                h_delta = 0
            else:
                h_delta = ev.delta()
                v_delta = 0
        else:
            delta = ev.angleDelta()
            h_delta = delta.x()
            v_delta = delta.y()

        mods = ev.modifiers()
        if Qt.ControlModifier == int(mods) and v_delta:
            self.zoomRequest.emit(v_delta)
        else:
            v_delta and self.scrollRequest.emit(v_delta, Qt.Vertical)
            h_delta and self.scrollRequest.emit(h_delta, Qt.Horizontal)
        ev.accept()

    def keyPressEvent(self, ev):
        key = ev.key()
        shapesBackup = copy.deepcopy(self.shapes)
        if len(shapesBackup) == 0:
            return
        self.shapesBackups.pop()
        self.shapesBackups.append(shapesBackup)
        if key == Qt.Key_Escape and self.current:
            print('ESC press')
            self.current = None
            self.drawingPolygon.emit(False)
            self.update()
        elif key == Qt.Key_Return and self.canCloseShape():
            self.finalise()
        elif key == Qt.Key_Left and self.selectedShapes:
             self.moveOnePixel('Left')
        elif key == Qt.Key_Right and self.selectedShapes:
             self.moveOnePixel('Right')
        elif key == Qt.Key_Up and self.selectedShapes:
             self.moveOnePixel('Up')
        elif key == Qt.Key_Down and self.selectedShapes:
             self.moveOnePixel('Down')
        elif key == Qt.Key_X and self.selectedShapes:
            for i in range(len(self.selectedShapes)):
                self.selectedShape = self.selectedShapes[i]
                if self.rotateOutOfBound(0.01):
                    continue
                self.selectedShape.rotate(0.01)
            self.shapeMoved.emit()
            self.update()

        elif key == Qt.Key_C and self.selectedShapes:
            for i in range(len(self.selectedShapes)):
                self.selectedShape = self.selectedShapes[i]
                if self.rotateOutOfBound(-0.01):
                    continue
                self.selectedShape.rotate(-0.01)
            self.shapeMoved.emit()
            self.update()

    def rotateOutOfBound(self, angle):
        for shape in range(len(self.selectedShapes)):
            self.selectedShape = self.selectedShapes[shape]
            for i, p in enumerate(self.selectedShape.points):
                if self.outOfPixmap(self.selectedShape.rotatePoint(p, angle)):
                    return True
            return False

    def moveOnePixel(self, direction):
        # print(self.selectedShape.points)
        self.selectCount = len(self.selectedShapes)
        self.selectCountShape = True
        for i in range(len(self.selectedShapes)):
            self.selectedShape = self.selectedShapes[i]
            if direction == 'Left' and not self.moveOutOfBound(QPointF(-1.0, 0)):
                # print("move Left one pixel")
                self.selectedShape.points[0] += QPointF(-1.0, 0)
                self.selectedShape.points[1] += QPointF(-1.0, 0)
                self.selectedShape.points[2] += QPointF(-1.0, 0)
                self.selectedShape.points[3] += QPointF(-1.0, 0)
            elif direction == 'Right' and not self.moveOutOfBound(QPointF(1.0, 0)):
                # print("move Right one pixel")
                self.selectedShape.points[0] += QPointF(1.0, 0)
                self.selectedShape.points[1] += QPointF(1.0, 0)
                self.selectedShape.points[2] += QPointF(1.0, 0)
                self.selectedShape.points[3] += QPointF(1.0, 0)
            elif direction == 'Up' and not self.moveOutOfBound(QPointF(0, -1.0)):
                # print("move Up one pixel")
                self.selectedShape.points[0] += QPointF(0, -1.0)
                self.selectedShape.points[1] += QPointF(0, -1.0)
                self.selectedShape.points[2] += QPointF(0, -1.0)
                self.selectedShape.points[3] += QPointF(0, -1.0)
            elif direction == 'Down' and not self.moveOutOfBound(QPointF(0, 1.0)):
                # print("move Down one pixel")
                self.selectedShape.points[0] += QPointF(0, 1.0)
                self.selectedShape.points[1] += QPointF(0, 1.0)
                self.selectedShape.points[2] += QPointF(0, 1.0)
                self.selectedShape.points[3] += QPointF(0, 1.0)
        shapesBackup = []
        shapesBackup = copy.deepcopy(self.shapes)
        self.shapesBackups.append(shapesBackup)
        self.shapeMoved.emit()
        self.repaint()

    def moveOutOfBound(self, step):
        points = [p1+p2 for p1, p2 in zip(self.selectedShape.points, [step]*4)]
        return True in map(self.outOfPixmap, points)

    def setLastLabel(self, text, line_color=None, fill_color=None, key_cls=None):
        assert text
        self.shapes[-1].label = text
        if line_color:
            self.shapes[-1].line_color = line_color

        if fill_color:
            self.shapes[-1].fill_color = fill_color

        if key_cls:
            self.shapes[-1].key_cls = key_cls

        self.storeShapes()

        return self.shapes[-1]

    def undoLastLine(self):
        assert self.shapes
        self.current = self.shapes.pop()
        self.current.setOpen()
        self.line.points = [self.current[-1], self.current[0]]
        self.drawingPolygon.emit(True)

    def undoLastPoint(self):
        if not self.current or self.current.isClosed():
            return
        self.current.popPoint()
        if len(self.current) > 0:
            self.line[0] = self.current[-1]
        else:
            self.current = None
            self.drawingPolygon.emit(False)
        self.repaint()

    def resetAllLines(self):
        assert self.shapes
        self.current = self.shapes.pop()
        self.current.setOpen()
        self.line.points = [self.current[-1], self.current[0]]
        self.drawingPolygon.emit(True)
        self.current = None
        self.drawingPolygon.emit(False)
        self.update()

    def loadPixmap(self, pixmap):
        self.pixmap = pixmap
        self.shapes = []
        self.repaint()

    def loadShapes(self, shapes, replace=True):
        if replace:
            self.shapes = list(shapes)
        else:
            self.shapes.extend(shapes)
        self.current = None
        self.hShape = None
        self.hVertex = None
        # self.hEdge = None
        self.storeShapes()
        self.updateShapeIndex()
        self.repaint()

    def setShapeVisible(self, shape, value):
        self.visible[shape] = value
        self.repaint()

    def currentCursor(self):
        cursor = QApplication.overrideCursor()
        if cursor is not None:
            cursor = cursor.shape()
        return cursor

    def overrideCursor(self, cursor):
        self._cursor = cursor
        if self.currentCursor() is None:
            QApplication.setOverrideCursor(cursor)
        else:
            QApplication.changeOverrideCursor(cursor)

    def restoreCursor(self):
        QApplication.restoreOverrideCursor()

    def resetState(self):
        self.restoreCursor()
        self.pixmap = None
        self.update()
        self.shapesBackups = []

    def setDrawingShapeToSquare(self, status):
        self.drawSquare = status

    def restoreShape(self):
        if not self.isShapeRestorable:
            return

        self.shapesBackups.pop()  # latest
        shapesBackup = self.shapesBackups.pop()
        self.shapes = shapesBackup
        self.selectedShapes = []
        for shape in self.shapes:
            shape.selected = False
        self.updateShapeIndex()
        self.repaint()
    
    @property
    def isShapeRestorable(self):
        if len(self.shapesBackups) < 2:
            return False
        return True

    def updateShapeIndex(self):
        for i in range(len(self.shapes)):
            self.shapes[i].idx = i
        self.update()