コード例 #1
0
class Canvas(QWidget):
    zoomRequest = pyqtSignal(int)
    scrollRequest = pyqtSignal(int, int)
    newShape = pyqtSignal()
    selectionChanged = pyqtSignal(bool)
    shapeMoved = pyqtSignal()
    drawingPolygon = pyqtSignal(bool)

    CREATE, EDIT = list(range(2))

    epsilon = 11.0

    def __init__(self, *args, **kwargs):
        super(Canvas, self).__init__(*args, **kwargs)
        # Initialise local state.
        self.mode = self.EDIT
        self.shapes = []
        self.current = None
        self.selectedShape = None  # save the selected shape here
        self.selectedShapeCopy = None
        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

    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:
                color = self.drawingLineColor
                if self.outOfPixmap(pos):
                    # Don't allow the user to draw outside the pixmap.
                    # Project the point to the pixmap's edges.
                    pos = self.intersectionPoint(self.current[-1], pos)
                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:
                    initPos = self.current[0]
                    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)
                else:
                    self.line[1] = pos

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

        # Polygon/Vertex moving or rotation.
        if Qt.LeftButton & ev.buttons(): # ev.buttons is mouse buttons mask (https://doc.qt.io/qt-5/qt.html#MouseButton-enum)
            if self.selectedVertex():
                self.boundedMoveVertex(pos)
                self.shapeMoved.emit()
                self.repaint()
            elif self.selectedShape and self.prevPoint:
                self.overrideCursor(CURSOR_MOVE)
                self.boundedMoveShape(self.selectedShape, pos)
                self.shapeMoved.emit()
                self.repaint()
            return
        elif Qt.RightButton & ev.buttons(): # ev.buttons is mouse buttons mask (https://doc.qt.io/qt-5/qt.html#MouseButton-enum)
            if self.selectedVertex():
                self.overrideCursor(CURSOR_CROSS)
                self.rotateVertex(pos)
                self.shapeMoved.emit()
                self.repaint()
            return
        
        # Polygon copy moving.
        if Qt.RightButton & ev.buttons():
            if self.selectedShapeCopy and self.prevPoint:
                self.overrideCursor(CURSOR_MOVE)
                self.boundedMoveShape(self.selectedShapeCopy, pos)
                self.repaint()
            elif self.selectedShape:
                self.selectedShapeCopy = self.selectedShape.copy()
                self.repaint()
            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("Left Click & Drag point to move. Right Click & Drag points to rotate.")
                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'. Right Click points to rotate." % 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)
            else:
                self.selectShapePoint(pos)
                self.prevPoint = pos
                self.repaint()
        elif ev.button() == Qt.RightButton and self.editing() and (not self.selectedVertex()):
            self.selectShapePoint(pos)
            self.prevPoint = pos
            self.repaint()

    def mouseReleaseEvent(self, ev):
        if ev.button() == Qt.RightButton and (not self.selectedVertex()):
            menu = self.menus[bool(self.selectedShapeCopy)]
            self.restoreCursor()
            if not menu.exec_(self.mapToGlobal(ev.pos()))\
               and self.selectedShapeCopy:
                # Cancel the move by deleting the shadow copy.
                self.selectedShapeCopy = None
                self.repaint()
        elif ev.button() == Qt.LeftButton and self.selectedShape:
            if self.selectedVertex():
                self.overrideCursor(CURSOR_POINT)
            else:
                self.overrideCursor(CURSOR_GRAB)
            
        elif ev.button() == Qt.LeftButton:
            pos = self.transformPos(ev.pos())
            if self.drawing():
                self.handleDrawing(pos)

    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

    def hideBackroundShapes(self, value):
        self.hideBackround = value
        if self.selectedShape:
            # 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:
            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)) # Adding canvas points is done here
            self.current.addPoint(targetPos)
            self.current.addPoint(QPointF(minX, maxY))
            self.finalise()
        elif not self.outOfPixmap(pos):
            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:
            self.current.popPoint()
            self.finalise()

    def selectShape(self, shape):
        self.deSelectShape()
        shape.selected = True
        self.selectedShape = shape
        self.setHiding()
        self.selectionChanged.emit(True)
        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
        for shape in reversed(self.shapes):
            if self.isVisible(shape) and shape.containsPoint(point):
                self.selectShape(shape)
                self.calculateOffsets(shape, point)
                return

    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 boundedMoveVertex(self, pos):
        index, shape = self.hVertex, self.hShape
        point = shape[index]
        if self.outOfPixmap(pos):
            pos = self.intersectionPoint(point, pos)

        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
        shape.moveVertexBy(index, shiftPos)
        
        # calculate the remaining first vertices
        dist_moved = math.sqrt( ((pos.x()-point.x())**2) + ((pos.y()-point.y())**2) )
        third_point_index = (index + 2) % 4
        
        pointToMove_index = (index + 1) % 4
        base = math.sqrt( ((shape.points[pointToMove_index].x()-shape.points[third_point_index].x())**2) +
                          ((shape.points[pointToMove_index].y()-shape.points[third_point_index].y())**2) )
        near_side_sqrd = ((shape.points[pointToMove_index].x()-pos.x())**2) + ((shape.points[pointToMove_index].y()-pos.y())**2)
        far_side_sqrd = ((shape.points[third_point_index].x()-pos.x())**2) + ((shape.points[third_point_index].y()-pos.y())**2)
        dist_to_moved = ((near_side_sqrd-far_side_sqrd)/base+base)/2
        shape.points[pointToMove_index].setX(shape.points[pointToMove_index].x() +
                          dist_to_moved * (shape.points[third_point_index].x() - shape.points[pointToMove_index].x() ) / base)
        shape.points[pointToMove_index].setY(shape.points[pointToMove_index].y() +
                          dist_to_moved * (shape.points[third_point_index].y() - shape.points[pointToMove_index].y() ) / base)       

        # calculate the remaining second vertices
        pointToMove_index = (index + 3) % 4
        base = math.sqrt( ((shape.points[pointToMove_index].x()-shape.points[third_point_index].x())**2) +
                          ((shape.points[pointToMove_index].y()-shape.points[third_point_index].y())**2) )
        near_side_sqrd = ((shape.points[pointToMove_index].x()-pos.x())**2) + ((shape.points[pointToMove_index].y()-pos.y())**2)
        far_side_sqrd = ((shape.points[third_point_index].x()-pos.x())**2) + ((shape.points[third_point_index].y()-pos.y())**2)
        dist_to_moved = ((near_side_sqrd-far_side_sqrd)/base+base)/2
        shape.points[pointToMove_index].setX(shape.points[pointToMove_index].x() +
                          dist_to_moved * (shape.points[third_point_index].x() - shape.points[pointToMove_index].x() ) / base)
        shape.points[pointToMove_index].setY(shape.points[pointToMove_index].y() +
                          dist_to_moved * (shape.points[third_point_index].y() - shape.points[pointToMove_index].y() ) / base)  

        
    def rotateVertex(self, pos):
        index, shape = self.hVertex, self.hShape
        point = shape[index]
        if self.outOfPixmap(pos):
            pos = self.intersectionPoint(point, pos)

        if not self.drawSquare:
            angle_target =   math.atan2(pos.y()  -shape.origin[1], pos.x()  -shape.origin[0])
            angle_original = math.atan2(point.y()-shape.origin[1], point.x()-shape.origin[0])
            shape.rotateBy(angle_target-angle_original, self.pixmap.width(), self.pixmap.height()) # Clock-wise

    def boundedMoveShape(self, shape, 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:
            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()

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

    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

    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.selectedShapeCopy:
            self.selectedShapeCopy.paint(p)

        # Paint rect
        if self.current is not None and len(self.line) == 2:
            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)

        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 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]:
            self.current = None
            self.drawingPolygon.emit(False)
            self.update()
            return
        
        self.current.updateOBBInfo()
        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

    def intersectionPoint(self, p1, p2):
        # Cycle through each image edge in clockwise fashion,
        # and find the one intersecting the current line segment.
        # http://paulbourke.net/geometry/lineline2d/
        size = self.pixmap.size()
        points = [(0, 0),
                  (size.width(), 0),
                  (size.width(), size.height()),
                  (0, size.height())]
        x1, y1 = p1.x(), p1.y()
        x2, y2 = p2.x(), p2.y()
        d, i, (x, y) = min(self.intersectingEdges((x1, y1), (x2, y2), points))
        x3, y3 = points[i]
        x4, y4 = points[(i + 1) % 4]
        if (x, y) == (x1, y1):
            # Handle cases where previous point is on one of the edges.
            if x3 == x4:
                return QPointF(x3, min(max(0, y2), max(y3, y4)))
            else:  # y3 == y4
                return QPointF(min(max(0, x2), max(x3, x4)), y3)
        return QPointF(x, y)

    def intersectingEdges(self, x1y1, x2y2, points):
        """For each edge formed by `points', yield the intersection
        with the line segment `(x1,y1) - (x2,y2)`, if it exists.
        Also return the distance of `(x2,y2)' to the middle of the
        edge along with its index, so that the one closest can be chosen."""
        x1, y1 = x1y1
        x2, y2 = x2y2
        for i in range(4):
            x3, y3 = points[i]
            x4, y4 = points[(i + 1) % 4]
            denom = (y4 - y3) * (x2 - x1) - (x4 - x3) * (y2 - y1)
            nua = (x4 - x3) * (y1 - y3) - (y4 - y3) * (x1 - x3)
            nub = (x2 - x1) * (y1 - y3) - (y2 - y1) * (x1 - x3)
            if denom == 0:
                # This covers two cases:
                #   nua == nub == 0: Coincident
                #   otherwise: Parallel
                continue
            ua, ub = nua / denom, nub / denom
            if 0 <= ua <= 1 and 0 <= ub <= 1:
                x = x1 + ua * (x2 - x1)
                y = y1 + ua * (y2 - y1)
                m = QPointF((x3 + x4) / 2, (y3 + y4) / 2)
                d = distance(m - QPointF(x2, y2))
                yield d, i, (x, y)

    # 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

        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 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):
        self.shapes = list(shapes)
        self.current = None
        for s in shapes:
            s.updateOBBInfo()
        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()

    def setDrawingShapeToSquare(self, status):
        self.drawSquare = status
コード例 #2
0
class Canvas(QWidget):
    zoomRequest = pyqtSignal(int)
    scrollRequest = pyqtSignal(int, int)
    newShape = pyqtSignal()
    selectionChanged = pyqtSignal(bool)
    shapeMoved = pyqtSignal()
    drawingPolygon = pyqtSignal(bool)

    CREATE, EDIT = list(range(2))

    epsilon = 11.0

    def __init__(self, *args, **kwargs):
        super(Canvas, self).__init__(*args, **kwargs)
        # Initialise local state.
        self.mode = self.EDIT
        self.shapes = []
        self.current = None
        self.selectedShape = None  # save the selected shape here
        self.selectedShapeCopy = None
        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.labelFontSize = 8
        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

        #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())
        modifiers = QApplication.keyboardModifiers()

        # 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:
                    initPos = self.current[0]
                    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)
                else:
                    self.line[1] = pos

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

        # Polygon/Vertex moving or rotation.
        if Qt.LeftButton & ev.buttons(
        ):  # ev.buttons is mouse buttons mask (https://doc.qt.io/qt-5/qt.html#MouseButton-enum)
            if self.selectedVertex():
                self.boundedMoveVertex(pos)
                self.shapeMoved.emit()
                self.repaint()
            elif self.selectedShape and self.prevPoint:
                self.overrideCursor(CURSOR_MOVE)
                if modifiers == Qt.ShiftModifier:
                    self.boundedMoveShapes(self.shapes, pos)
                else:
                    self.boundedMoveShape(self.selectedShape, pos)
                self.shapeMoved.emit()
                self.repaint()
            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
        elif Qt.RightButton & ev.buttons(
        ):  # ev.buttons is mouse buttons mask (https://doc.qt.io/qt-5/qt.html#MouseButton-enum)
            if self.selectedVertex():
                self.overrideCursor(CURSOR_CROSS)
                if modifiers == Qt.ShiftModifier:
                    self.rotateVertexAll(pos)
                else:
                    self.rotateVertex(pos)
                self.shapeMoved.emit()
                self.repaint()
            return

        # Polygon copy moving.
        if Qt.RightButton & ev.buttons():
            if self.selectedShapeCopy and self.prevPoint:
                self.overrideCursor(CURSOR_MOVE)
                self.boundedMoveShape(self.selectedShapeCopy, pos)
                self.repaint()
            elif self.selectedShape:
                self.selectedShapeCopy = self.selectedShape.copy()
                self.repaint()
            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(
                    "Left Click & Drag point to move. Right Click & Drag points to rotate."
                )
                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'. Right Click points to rotate."
                    % 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)
            else:
                selection = self.selectShapePoint(pos)
                self.prevPoint = pos

                #         if selection is None:
                #             #pan
                #             QApplication.setOverrideCursor(QCursor(Qt.OpenHandCursor))
                #             self.pan_initial_pos = pos

                # elif ev.button() == Qt.RightButton and self.editing():
                self.repaint()
        elif ev.button() == Qt.RightButton and self.editing() and (
                not self.selectedVertex()):
            self.selectShapePoint(pos)
            self.prevPoint = pos
        self.update()

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

        elif ev.button() == Qt.LeftButton:
            pos = self.transformPos(ev.pos())
            if self.drawing():
                self.handleDrawing(pos)
            else:
                #pan
                QApplication.restoreOverrideCursor()

    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

    def hideBackroundShapes(self, value):
        self.hideBackround = value
        if self.selectedShape:
            # 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:
            initPos = self.current[0]
            minX = initPos.x()
            minY = initPos.y()
            targetPos = self.line[1]
            maxX = targetPos.x()
            maxY = targetPos.y()

            if minX == maxX:
                maxX = maxX + 1
            if minY == maxY:
                maxY = maxY + 1

            self.current.addPoint(QPointF(
                maxX, minY))  # Adding canvas points is done here
            self.current.addPoint(targetPos)
            self.current.addPoint(QPointF(minX, maxY))
            self.finalise()
        elif not self.outOfPixmap(pos):
            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:
            self.current.popPoint()
            self.finalise()

    def selectShape(self, shape):
        self.deSelectShape()
        shape.selected = True
        self.selectedShape = shape
        self.setHiding()
        self.selectionChanged.emit(True)
        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)
                self.calculateOffsets(shape, point)
                return self.selectedShape
        return None

    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)

        opposite_point_index = (index + 2) % 4
        o_to_pos_vector = Vector(shape[opposite_point_index], pos)
        o_to_prev_vector = Vector(shape[opposite_point_index],
                                  shape[(index + 3) % 4])
        o_to_next_vector = Vector(shape[opposite_point_index],
                                  shape[(index + 1) % 4])

        if self.drawSquare:
            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:
            o_to_pos_mag = o_to_pos_vector.magnitude()
            o_to_prev_mag = o_to_prev_vector.magnitude()
            o_to_next_mag = o_to_next_vector.magnitude()

            o_to_pos_u_vector = QPointF(o_to_pos_vector.x / o_to_pos_mag,
                                        o_to_pos_vector.y / o_to_pos_mag)
            o_to_prev_u_vector = QPointF(o_to_prev_vector.x / o_to_prev_mag,
                                         o_to_prev_vector.y / o_to_prev_mag)
            o_to_next_u_vector = QPointF(o_to_next_vector.x / o_to_next_mag,
                                         o_to_next_vector.y / o_to_next_mag)

            if o_to_pos_u_vector.x() == o_to_prev_u_vector.x(
            ) and o_to_pos_u_vector.y() == o_to_prev_u_vector.y():
                pos = pos + o_to_next_u_vector
            if o_to_pos_u_vector.x() == o_to_next_u_vector.x(
            ) and o_to_pos_u_vector.y() == o_to_next_u_vector.y():
                pos = pos + o_to_prev_u_vector

            shiftPos = pos - point

        point_to_pos_vector = Vector(point, pos)

        prev_proj = point_to_pos_vector.projection(o_to_prev_vector)
        next_proj = point_to_pos_vector.projection(o_to_next_vector)

        prev_shiftPos = QPointF(o_to_prev_vector.x * prev_proj,
                                o_to_prev_vector.y * prev_proj)
        next_shiftPos = QPointF(o_to_next_vector.x * next_proj,
                                o_to_next_vector.y * next_proj)

        shape.moveVertexBy(index, shiftPos)
        shape.moveVertexBy((index + 3) % 4, prev_shiftPos)
        shape.moveVertexBy((index + 1) % 4, next_shiftPos)

    def rotateVertex(self, pos):
        index, shape = self.hVertex, self.hShape
        point = shape[index]
        if self.outOfPixmap(pos):
            pos = self.intersectionPoint(point, pos)

        if not self.drawSquare:
            angle_target = math.atan2(pos.y() - shape.origin[1],
                                      pos.x() - shape.origin[0])
            angle_original = math.atan2(point.y() - shape.origin[1],
                                        point.x() - shape.origin[0])
            shape.rotateBy(angle_target - angle_original, self.pixmap.width(),
                           self.pixmap.height())  # Clock-wise

    def rotateVertexAll(self, pos):
        index, shape = self.hVertex, self.hShape
        point = shape[index]
        if self.outOfPixmap(pos):
            pos = self.intersectionPoint(point, pos)

        if not self.drawSquare:
            angle_target = math.atan2(pos.y() - shape.origin[1],
                                      pos.x() - shape.origin[0])
            angle_original = math.atan2(point.y() - shape.origin[1],
                                        point.x() - shape.origin[0])
            for s in self.shapes:
                s.rotateBy(angle_target - angle_original, self.pixmap.width(),
                           self.pixmap.height())  # Clock-wise

    def boundedMoveShape(self, shape, 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:
            shape.moveBy(dp)
            self.prevPoint = pos
            return True
        return False

    def boundedMoveShapes(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 s in self.shapes:
                s.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()

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

    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

    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
        Shape.labelFontSize = self.labelFontSize
        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.selectedShapeCopy:
            self.selectedShapeCopy.paint(p)

        # Paint rect
        if self.current is not None and len(self.line) == 2:
            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)

        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 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]:
            self.current = None
            self.drawingPolygon.emit(False)
            self.update()
            return

        self.current.updateOBBInfo()
        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()
        modifiers = QApplication.keyboardModifiers()

        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', move_all=(modifiers == Qt.ShiftModifier))
        elif key == Qt.Key_Right and self.selectedShape:
            self.moveOnePixel('Right',
                              move_all=(modifiers == Qt.ShiftModifier))
        elif key == Qt.Key_Up and self.selectedShape:
            self.moveOnePixel('Up', move_all=(modifiers == Qt.ShiftModifier))
        elif key == Qt.Key_Down and self.selectedShape:
            self.moveOnePixel('Down', move_all=(modifiers == Qt.ShiftModifier))

    def moveOnePixel(self, direction, move_all=False):
        movement = QPointF(0, 0)
        # print(self.selectedShape.points)
        if direction == 'Left' and not self.moveOutOfBound(QPointF(-1.0, 0)):
            # print("move Left one pixel")
            movement = QPointF(-1, 0)
        elif direction == 'Right' and not self.moveOutOfBound(QPointF(1.0, 0)):
            # print("move Right one pixel")
            movement = QPointF(1, 0)
        elif direction == 'Up' and not self.moveOutOfBound(QPointF(0, -1.0)):
            # print("move Up one pixel")
            movement = QPointF(0, -1)
        elif direction == 'Down' and not self.moveOutOfBound(QPointF(0, 1.0)):
            # print("move Down one pixel")
            movement = QPointF(0, 1)

        if move_all:
            for shape in self.shapes:
                shape.moveBy(movement)
        else:
            self.selectedShape.moveBy(movement)

        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

        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 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):
        self.shapes = list(shapes)
        self.current = None
        for s in shapes:
            s.updateOBBInfo()
        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()

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