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.

try:
    from PyQt5.QtGui import *
    from PyQt5.QtCore import *
    from PyQt5.QtWidgets import *
except ImportError:
    from PyQt4.QtGui import *
    from PyQt4.QtCore import *

#from PyQt4.QtOpenGL import *

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(QGLWidget):


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 = 11.0

    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

        #initialisation for panning
        self.pan_initial_pos = QPoint()

    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]):# and not self.fourpoint:
                    # 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)
                # elif ( # ADD # 合并上下代码 内容一样
                #         len(self.current) > 1
                #         and self.fourpoint
                #         and self.closeEnough(pos, self.current[0])
                # ):
                #     # Attract line to starting point and
                #     # colorise to alert the user.
                #     pos = self.current[0]
                #     self.overrideCursor(CURSOR_POINT)
                #     self.current.highlightVertex(0, Shape.NEAR_VERTEX)


                if self.drawSquare: # 这部分不同
                    # initPos = self.current[0] # 原先代码
                    # minX = initPos.x()
                    # minY = initPos.y()
                    # min_size = min(abs(pos.x() - minX), abs(pos.y() - minY))
                    # directionX = -1 if pos.x() - minX < 0 else 1
                    # directionY = -1 if pos.y() - minY < 0 else 1
                    # self.line[1] = QPointF(minX + directionX * min_size, minY + directionY * min_size)

                    self.line.points = [self.current[0], pos] # Labelme代码
                    self.line.close()

                elif self.fourpoint:
                    # self.line[self.pointnum] = pos # OLD
                    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
        # 一下都相同
        # 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() # 同时选中时的移动
                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: # TODO 这部分是多的
                #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()
                # TODO： Pre部分的变量都没有
                self.hVertex, self.hShape = index, shape # 倒着来的原因是要更新hShape的值？
                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: # 增加
                        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 = Shape(shape_type=self.createMode) # TODO: 有可能需要制定类型？
                    self.current.addPoint(pos)
                    # if self.createMode == "point":
                    #     self.finalise()
                    # else:
                    #     if self.createMode == "circle":
                    #         self.current.shape_type = "circle"
                    self.line.points = [pos, pos]
                    self.setHiding()
                    self.drawingPolygon.emit(True)
                    self.update()

            else: # 改动后可以增加多选框，选点方式从单点变成list
                # selection = self.selectShapePoint(pos)
                # self.prevPoint = pos
                #
                # if selection is None:
                #     #pan
                #     QApplication.setOverrideCursor(QCursor(Qt.OpenHandCursor))
                #     self.pan_initial_pos = pos
                group_mode = int(ev.modifiers()) == Qt.ControlModifier
                self.selectShapePoint(pos, multiple_selection_mode=group_mode)
                self.prevPoint = pos
                self.pan_initial_pos = pos
                # self.repaint()

        elif ev.button() == Qt.RightButton and self.editing():
            # self.selectShapePoint(pos)
            # self.prevPoint = pos
            group_mode = int(ev.modifiers()) == Qt.ControlModifier
            self.selectShapePoint(pos, multiple_selection_mode=group_mode)
            self.prevPoint = pos
            # self.repaint() # 只用update？
        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.selectedShape: # OLD
        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: # 暂时去除四点部分的代码
            pos = self.transformPos(ev.pos())
            if self.drawing():
                self.handleDrawing(pos) # 关键函数
            else:
                #pan
                QApplication.restoreOverrideCursor() # ?

        if self.movingShape and self.hShape: # 加上之后会移动点会崩 用于撤回
             index = self.shapes.index(self.hShape)
             if (
                 self.shapesBackups[-1][index].points # 如果新建的框位置变化
                 != self.shapes[index].points
             ):
                 self.storeShapes() # 重新backup一下
                 self.shapeMoved.emit() # 连接updateBoxlist

             self.movingShape = False


    def endMove(self, copy=False):
        # assert self.selectedShape and self.selectedShapeCopy
        # shape = self.selectedShapeCopy
        #del shape.fill_color
        #del shape.line_color
        # if copy:
        #     self.shapes.append(shape)
        #     self.selectedShape.selected = False
        #     self.selectedShape = shape
        #     self.repaint()
        # else:
        #     self.selectedShape.points = [p for p in shape.points]
        # self.selectedShapeCopy = None
        assert self.selectedShapes and self.selectedShapesCopy
        assert len(self.selectedShapesCopy) == len(self.selectedShapes)
        if copy:
            for i, shape in enumerate(self.selectedShapesCopy):
                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): # 没有此函数
        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: # 按住送掉后跳到这里
                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):
        # self.deSelectShape()
        # shape.selected = True
        # self.selectedShape = shape
        # self.setHiding()
        # self.selectionChanged.emit(True)
        # self.update()
        for s in shapes: s.seleted = True
        self.setHiding()
        self.selectionChanged.emit(shapes)
        self.update()

    # def selectShapePoint(self, point):
    #     """Select the first shape created which contains this point."""
    #     self.deSelectShape()
    #     if self.selectedVertex():  # A vertex is marked for selection.
    #         index, shape = self.hVertex, self.hShape
    #         shape.highlightVertex(index, shape.MOVE_VERTEX)
    #         self.selectShape(shape)
    #         return self.hVertex
    #     for shape in reversed(self.shapes):
    #         if self.isVisible(shape) and shape.containsPoint(point):
    #             self.selectShape(shape) # 函数
    #             self.calculateOffsets(shape, point)
    #             return self.selectedShape
    #     return None

    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) # 突出显示

            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 TODO:为什么是2个，刚开始应该是1个
                            self.selectionChanged.emit(
                                self.selectedShapes + [shape] # 选择+未选择
                            )
                    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[3].x() and shape[1].x()==shape[2].x() and shape[0].y()==shape[1].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 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)
            self.prevPoint = pos
            return True
        return False

    def deSelectShape(self):
        # if self.selectedShape:
        #     self.selectedShape.selected = False
        #     self.selectedShape = None
        #     self.setHiding(False)
        #     self.selectionChanged.emit(False)
        #     self.update()
        if self.selectedShapes:
            # TODO：少了两个清空？
            for shape in self.selectedShapes: shape.selected=False
            self.setHiding(False)
            self.selectionChanged.emit([])
            self.update()

    # def deleteSelected(self):
    #     if self.selectedShape:
    #         shape = self.selectedShape
    #         self.shapes.remove(self.selectedShape)
    #         self.selectedShape = None
    #         self.update()
    #         return shape

    def deleteSelected(self):
        deleted_shapes = []
        if self.selectedShapes:
            #self.storeShapes()
            for shape in self.selectedShapes:
                self.shapes.remove(shape)
                #self.shapesBackups.append(shape)
                deleted_shapes.append(shape)
            self.storeShapes() # 这里应该是先储存
            self.selectedShapes = []
            self.update()
        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) # 每删除或保存一次都会backup一次

    def copySelectedShape(self):
        # if self.selectedShape:
        #     shape = self.selectedShape.copy()
        #     self.deSelectShape()
        #     self.shapes.append(shape)
        #     shape.selected = True
        #     self.selectedShape = shape
        #     self.boundedShiftShape(shape)
        #     return shape
        if self.selectedShapes:
            self.selectedShapesCopy = [s.copy() for s in self.selectedShapes]
            self.boundedShiftShapes(self.selectedShapesCopy)
            self.endMove(copy=True)
        return self.selectedShapes

    def boundedShiftShape(self, shape):
        # Try to move in one direction, and if it fails in another.
        # Give up if both fail.
        point = shape[0]
        offset = QPointF(2.0, 2.0)
        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)

        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.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()
        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.selectedShape:
        #     self.moveOnePixel('Left')
        # elif key == Qt.Key_Right and self.selectedShape:
        #     self.moveOnePixel('Right')
        # elif key == Qt.Key_Up and self.selectedShape:
        #     self.moveOnePixel('Up')
        # elif key == Qt.Key_Down and self.selectedShape:
        #     self.moveOnePixel('Down')

    def moveOnePixel(self, direction):
        # print(self.selectedShape.points)
        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)
        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):
        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
        #self.shapesBackups.pop() # 新建shape后要pop?
        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.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): # 用于撤销
        if not self.isShapeRestorable:
            return
        self.shapesBackups.pop()  # latest
        shapesBackup = self.shapesBackups.pop()
        self.shapes = shapesBackup
        #self.shapes.append(self.shapesBackups.pop()) # 为何这里之前是只将back赋值呢
        self.selectedShapes = []
        for shape in self.shapes:
            shape.selected = False
        self.repaint()

    @property
    def isShapeRestorable(self):
        if len(self.shapesBackups) < 2:
            return False
        return True