本文主要介绍PyQt5编写的*绘画板工具，涉及三个层面的内容，如QgraphicsView、QgraphicsScene和QgraphicsItem。功能如下GIF所示。主要是QgraphicsView重写鼠标事件，QgraphicsScene设置场景大小，还有各种QgraphicsItem的重写，其中包括了QgraphicsTextItem、QgraphicsPathItem、QgraphicsRectItem等，也参考了网上很多帖子的思路和代码。整体思路的代码帖再下面，有兴趣的读者可以作为参考参考。也请各路大神完善完善。
class MyScene(QGraphicsScene):#自定场景
pen_color=Qt.red #预设笔的颜色
pen_width = 5 #预设笔的宽度
Eraser_pen_width=20 #预设橡皮擦的宽度
def __init__(self):#初始函数
super(MyScene, self).__init__(parent=None) #实例化QGraphicsScene
self.setSceneRect(0,0,600,500) #设置场景起始及大小，默认场景是中心为起始，不方便后面的代码
# self.setForegroundBrush(Qt.white)
self.EraseMode=False
self.shape= "Free pen"
# rect=QGraphicsRectItem(0,0,50,50)
# rect.setFlags(QGraphicsItem.ItemIsSelectable | QGraphicsItem.ItemIsMovable)
# rect.setPos(60,100)
# self.addItem(rect)
def drawBackground(self, painter: QPainter, rect: QRectF):
painter.drawRect(0,0,600,500)
def Eraser(self,b=False):
self.EraseMode = b
return self.EraseMode
def Shape(self, s):
self.shape = s
return self.Shape
def ChangePenColor(self, color):
self.pen_color = QColor(color)
def ChangePenThickness(self, thickness):
self.pen_width=thickness
def ChangeEraserThickness(self,EraserThickness):
self.Eraser_pen_width=EraserThickness
class GraphicView(QGraphicsView):
def __init__(self, parent=None):
super().__init__(parent)
try:
self.scene = MyScene() # 设置管理QgraphicsItems的场景
self.shape = "Free pen" # 预设画笔为*风格画笔
self.pen_color = Qt.red # 预设笔的颜色
self.pen_width = 5 # 预设笔的宽度
# 预设以下参数的值，以防画板打开第一时间操作导入图片后self.wx-self.x=None-None而出错
self.x=0
self.y=0
self.wx=0
self.wy=0
self.setScene(self.scene) # Qgraphicsview设置场景MyScene()
except Exception as e:
print(e)
def Shape(self, s):
"""返回画笔属性状态"""
self.shape = s
if self.shape == "move":
self.setDragMode(QGraphicsView.RubberBandDrag) # 设置为支持橡皮筋框选模式
else:
self.setDragMode(QGraphicsView.NoDrag) # 其他情况设置为不可拖拽模式
return self.shape
def ChangePenColor(self, color):
"""返回变更的画笔颜色"""
self.pen_color = QColor(color) # 当画笔颜色变化时，设置画笔颜色
return self.pen_color
def ChangePenThickness(self, thickness):
"""返回变更的画笔粗细"""
self.pen_width=thickness # 当画笔颜色变化时，设置画笔粗细
def get_item_at_click(self, event): # 返回鼠标点击的QgraphicsItem
""" 返回你所点击的item """
pos = event.pos() # 注意此时是Qgraphicsview的鼠标点击位置
# x=self.graphicsView.mapFromParent(pos)
# y=self.graphicsView.mapFromScene(pos)
# z=self.graphicsView.mapFromGlobal(pos)
# print(pos,x,y,z)
# print(pos)
item = self.itemAt(pos)
return item
def mousePressEvent(self, event):
"""重载鼠标按下事件"""
super(GraphicView,self).mousePressEvent(event) # 此重置句必须要有，目的是为了画完Item后Item可被选择
try:
self.lastPoint = event.pos() # 记录鼠标在Qgraphicsview按下的位置点
self.x = self.lastPoint.x()
self.y = self.lastPoint.y()
pos = event.pos() # 记录鼠标按下的位置
self.t=self.mapToScene(pos)
item = self.get_item_at_click(event) # 记录鼠标点击Item的信息，若无Item，此函数返回None
""""鼠标右键按下Item时，将其删除事件"""
if event.button() == Qt.RightButton:
if isinstance(item, QGraphicsItem):
self.scene.removeItem(item)
""""触发鼠标左件事件"""
if event.button() == Qt.LeftButton:
self.tempPath = QGraphicsPathItem() # 设置一个内存上的QGraphicsPathItem，方便MouseMoveEvent画图时有双缓冲绘图效果
self.tempPath.setFlags(QtWidgets.QGraphicsItem.ItemIsSelectable
| QtWidgets.QGraphicsItem.ItemIsMovable
| QtWidgets.QGraphicsItem.ItemIsFocusable
| QtWidgets.QGraphicsItem.ItemSendsGeometryChanges
| QtWidgets.QGraphicsItem.ItemSendsScenePositionChanges)
self.path1 = QPainterPath() # 实例路径函数，用于*画笔风格
self.path1.moveTo(pos) # 设置路径开始点
if self.shape == "line":
self.a = Arrow(self.scene, self.pen_color, self.pen_width) # 设置实例化自定义的箭头类，但不传入起始点位置参数
self.a.set_src(self.x, self.y) # 设置自定义箭头类的箭头线起始点
# 千万不要再初始化__init__那里设置画笔Qpen，不然笔颜色，大小无法修改
pp=QPen() # 实例QPen
pp.setColor(self.pen_color) #设置颜色
pp.setWidth(self.pen_width) #设置宽度
self.tempPath.setPen(pp) # self.tempPath应用笔
if item != None:
self.wl=item.boundingRect().width()
PaintBoard1().wc(self.wl)
except Exception as e:
print(e)
def mouseMoveEvent(self,event):
"""重载鼠标移动事件"""
super(GraphicView, self).mouseMoveEvent(event) # 此重置句必须要有，目的是为了画完Item后Item可被移动，可放在MouseMoveEvent最后
self.endPoint = event.pos() # 返回鼠标移动时的点位置
self.wx = self.endPoint.x()
self.wy = self.endPoint.y()
self.w = self.wx-self.x # 用于绘画矩形Rect和Ellipse图形时的宽（长）
self.h = self.wy-self.y # 用于绘画矩形Rect和Ellipse图形时的高（宽）
self.m = self.mapFromScene(event.pos())
item = self.get_item_at_click(event)
if event.buttons() & Qt.LeftButton : #仅左键时触发，event.button返回notbutton，需event.buttons()判断，这应是对象列表，用&判断
try:
# if item != None and isinstance(item,QGraphicsRectItem)==False:
if item != None and item.type() != 4: # 判断自定义的图片类（自己设置了图片的type()=4）时，画笔可以在图片上画图，而不会使图片在绘图时移动
super(GraphicView, self).mouseMoveEvent(event)
elif self.shape=="circle": # 圆形的item.type()=3
self.setCursor(Qt.ArrowCursor) # 设置鼠标形状
if item == None: # 若无点击Item时，画笔可以画圆形
pass
else: # 若鼠标有点击图片类Item，设置该图片图元不可被选择和不可移动
item.setFlag(QGraphicsItem.ItemIsMovable,enabled=False)
item.setFlag(QGraphicsItem.ItemIsSelectable,enabled=False)
self.path2 = QPainterPath() # 为了实现双缓冲的效果，另设一个QPainterPath
self.path2.addEllipse(self.t.x(), self.t.y(), self.w, self.h) # 添加绘图路径
self.tempPath.setPath(self.path2) # 由于self.path2是在内存上一直刷新，并销毁之前的绘图路径，此时tempath设置路径就能在绘图时有双缓冲效果
self.scene.addItem(self.tempPath) # Myscene()场景中添加图元
elif self.shape=="rect": # 矩形的item.type()=3
self.setCursor(Qt.ArrowCursor)
if item == None:
pass
else:
item.setFlag(QGraphicsItem.ItemIsSelectable, enabled=False)
item.setFlag(QGraphicsItem.ItemIsMovable,enabled=False)
self.path3 = QPainterPath()
self.path3.addRect(self.x, self.y, self.w, self.h)
self.tempPath.setPath(self.path3)
self.scene.addItem(self.tempPath)
elif self.shape=="Free pen": # *风格画笔绘图的图元item.type()==2
self.setCursor(Qt.ArrowCursor)
if item == None:
pass
elif item != None:
item.setFlag(QGraphicsItem.ItemIsSelectable, enabled=False)
item.setFlag(QGraphicsItem.ItemIsMovable,enabled=False)
if self.path1: # 即self.path1==True
self.path1.lineTo(event.pos()) # 移动并连接点
self.tempPath.setPath(self.path1) # self.QGraphicsPath添加路径，如果写在上面的函数，是没线显示的，写在下面则在松键才出现线
self.scene.addItem(self.tempPath)
elif self.shape=="line": # 箭头类图元item.type()==2
self.setCursor(Qt.ArrowCursor)
if item == None:
pass
else:
item.setFlag(QGraphicsItem.ItemIsSelectable, enabled=False)
item.setFlag(QGraphicsItem.ItemIsMovable, enabled=False)
self.a.set_dst(self.wx, self.wy) # 更新箭头类线条的末端点位置
self.a.update() # 自定义箭头类图元刷新，不然没有双缓冲绘图效果
self.scene.addItem(self.a)
elif self.shape=="move": # 设置当self.shape=="Move"时，不做其他附加操作
self.setCursor(Qt.SizeAllCursor)
if item==None:
pass
else:
item.setFlag(QGraphicsItem.ItemIsSelectable,enabled=True)
item.setFlag(QGraphicsItem.ItemIsMovable,enabled=True)
except Exception as e:
print(e)
# super().mouseMoveEvent(event) # 该重置鼠标移动事件语句也可以写在这里
def mouseReleaseEvent(self, event):
super().mouseReleaseEvent(event) # 此重置句必须要有，目的是为了画完Item后Item，Item不会出现移动bug
item = self.get_item_at_click(event)
try:
if self.shape=="rect":
if item.isSelected():
pass
else:
self.scene.removeItem(self.tempPath)
self.r = RectItem(self.pen_color,self.pen_width,self.tempPath.boundingRect())
self.scene.addItem(self.r)
elif self.shape == "circle":
self.scene.removeItem(self.tempPath)
self.e = EllipseItem(self.pen_color,self.pen_width,self.tempPath.boundingRect())
self.scene.addItem(self.e)
except Exception as e:
print(e)
# super().mouseReleaseEvent(event) # 该重置鼠标移动事件语句也可以写在这里
def get_items_at_rubber(self):
""" 返回选择区域内的Items"""
area = self.graphicsView.rubberBandRect()
return self.graphicsView.items(area)
# def wheelEvent(self, event): # 可以利用鼠标滚轮进行Item的缩放或旋转
# """ 重载鼠标滚轮事件"""
# try:
# #factor = 1.41 ** (-event.delta() / 240.0)
# item=self.get_item_at_click(event)
# t=[]
# f = event.angleDelta().y()/120.0
# t.append(f)
# print(len(t))
# if event.angleDelta().y()/120.0 > 0:
# factor=1.2
# else:
# factor=0.8
# # item.setScale(factor)
# item.setRotation(30)
# # item.boundingRect().adjust()
#
# except Exception as e:
# print(e)
class PItem(QGraphicsRectItem):
""" 导入图片可缩放的自定义图片类，实际是重写QGraphicsRectItem类"""
handleTopLeft = 1
handleTopMiddle = 2
handleTopRight = 3
handleMiddleLeft = 4
handleMiddleRight = 5
handleBottomLeft = 6
handleBottomMiddle = 7
handleBottomRight = 8
handleSize = +10.0
handleSpace = -4.0
# 设置鼠标形状
handleCursors = {
handleTopLeft: Qt.SizeFDiagCursor,
handleTopMiddle: Qt.SizeVerCursor,
handleTopRight: Qt.SizeBDiagCursor,
handleMiddleLeft: Qt.SizeHorCursor,
handleMiddleRight: Qt.SizeHorCursor,
handleBottomLeft: Qt.SizeBDiagCursor,
handleBottomMiddle: Qt.SizeVerCursor,
handleBottomRight: Qt.SizeFDiagCursor,
}
def __init__(self, filename, *args):
"""初始化图形类基础信息"""
super().__init__(*args)
self.filename = filename # 记录导入的图片存储路径
self.setZValue(-1) # 使插入的图片在Myscene()的-1层
self.pix = QPixmap(filename) # 设置Pixmap为导入的图片
self.g = PaintBoard1()
self.handles = {}
self.handleSelected = None
self.mousePressPos = None
self.mousePressRect = None
self.setAcceptHoverEvents(True)
self.setFlag(QGraphicsItem.ItemIsMovable, True)
self.setFlag(QGraphicsItem.ItemIsSelectable, True)
self.setFlag(QGraphicsItem.ItemSendsGeometryChanges, True)
self.setFlag(QGraphicsItem.ItemIsFocusable, True)
self.updateHandlesPos()
def type(self):
type = 4 # 重写本次自定义图片类的Item.type()的值为4
return type
def handleAt(self, point): # point为鼠标的点位置信息
"""返回自设定的小handle是否包含鼠标所在的点位置，若是，则返回鼠标在第几个handle上"""
for k, v, in self.handles.items(): # k为数值1~8，辨别是handleTopLeft=1还是其他；v则是返回小handle的QRectF
if v.contains(point):
return k
return None
def hoverMoveEvent(self, moveEvent):
"""执行鼠标在图片上移动的事件（非鼠标点击事件）"""
if self.isSelected():
handle = self.handleAt(moveEvent.pos())
cursor = Qt.ArrowCursor if handle is None else self.handleCursors[handle]
self.setCursor(cursor)
super().hoverMoveEvent(moveEvent)
def hoverLeaveEvent(self, moveEvent):
"""执行鼠标移动到图片外边的事件（非鼠标点击事件）"""
self.setCursor(Qt.ArrowCursor)
super().hoverLeaveEvent(moveEvent)
def mousePressEvent(self, mouseEvent):
"""执行鼠标在图片上点击事件"""
self.handleSelected = self.handleAt(mouseEvent.pos())
if self.handleSelected:
self.mousePressPos = mouseEvent.pos()
self.mousePressRect = self.boundingRect() # 返回点击的Rect的boundingRect虚函数
super().mousePressEvent(mouseEvent)
def mouseMoveEvent(self, mouseEvent):
"""执行鼠标在图片上点击后按住鼠标移动的事件"""
if self.handleSelected is not None:
self.interactiveResize(mouseEvent.pos()) # 此句鼠标点击图片并移动时返回None值
else:
super().mouseMoveEvent(mouseEvent)
def mouseReleaseEvent(self, mouseEvent):
"""执行鼠标在图片上释放事件"""
super().mouseReleaseEvent(mouseEvent)
# 重设以下参数
self.handleSelected = None
self.mousePressPos = None
self.mousePressRect = None
self.update()
def boundingRect(self):
"""返回图形的boundingRect，其中包含resize handles的boundingRect"""
o = self.handleSize + self.handleSpace
return self.rect().adjusted(-o, -o, o, o)
def updateHandlesPos(self):
"""基于图形的形状尺寸和位置，更新现有的resize handles位置"""
s = self.handleSize
b = self.boundingRect()
self.handles[self.handleTopLeft] = QRectF(b.left(), b.top(), s, s)
self.handles[self.handleTopMiddle] = QRectF(b.center().x() - s / 2, b.top(), s, s)
self.handles[self.handleTopRight] = QRectF(b.right() - s, b.top(), s, s)
self.handles[self.handleMiddleLeft] = QRectF(b.left(), b.center().y() - s / 2, s, s)
self.handles[self.handleMiddleRight] = QRectF(b.right() - s, b.center().y() - s / 2, s, s)
self.handles[self.handleBottomLeft] = QRectF(b.left(), b.bottom() - s, s, s)
self.handles[self.handleBottomMiddle] = QRectF(b.center().x() - s / 2, b.bottom() - s, s, s)
self.handles[self.handleBottomRight] = QRectF(b.right() - s, b.bottom() - s, s, s)
def interactiveResize(self, mousePos):
"""用于交互式的矩形变换，如重设点位置"""
offset = self.handleSize + self.handleSpace
boundingRect = self.boundingRect()
rect = self.rect()
diff = QPointF(0, 0)
self.prepareGeometryChange()
if self.handleSelected == self.handleTopLeft:
fromX = self.mousePressRect.left()
fromY = self.mousePressRect.top()
toX = fromX + mousePos.x() - self.mousePressPos.x()
toY = fromY + mousePos.y() - self.mousePressPos.y()
diff.setX(toX - fromX)
diff.setY(toY - fromY)
boundingRect.setLeft(toX)
boundingRect.setTop(toY)
rect.setLeft(boundingRect.left() + offset)
rect.setTop(boundingRect.top() + offset)
self.setRect(rect)
elif self.handleSelected == self.handleTopMiddle:
fromY = self.mousePressRect.top()
toY = fromY + mousePos.y() - self.mousePressPos.y()
diff.setY(toY - fromY)
boundingRect.setTop(toY)
rect.setTop(boundingRect.top() + offset)
self.setRect(rect)
elif self.handleSelected == self.handleTopRight:
fromX = self.mousePressRect.right()
fromY = self.mousePressRect.top()
toX = fromX + mousePos.x() - self.mousePressPos.x()
toY = fromY + mousePos.y() - self.mousePressPos.y()
diff.setX(toX - fromX)
diff.setY(toY - fromY)
boundingRect.setRight(toX)
boundingRect.setTop(toY)
rect.setRight(boundingRect.right() - offset)
rect.setTop(boundingRect.top() + offset)
self.setRect(rect)
elif self.handleSelected == self.handleMiddleLeft:
fromX = self.mousePressRect.left()
toX = fromX + mousePos.x() - self.mousePressPos.x()
diff.setX(toX - fromX)
boundingRect.setLeft(toX)
rect.setLeft(boundingRect.left() + offset)
self.setRect(rect)
elif self.handleSelected == self.handleMiddleRight:
fromX = self.mousePressRect.right()
toX = fromX + mousePos.x() - self.mousePressPos.x()
diff.setX(toX - fromX)
boundingRect.setRight(toX)
rect.setRight(boundingRect.right() - offset)
self.setRect(rect)
elif self.handleSelected == self.handleBottomLeft:
fromX = self.mousePressRect.left()
fromY = self.mousePressRect.bottom()
toX = fromX + mousePos.x() - self.mousePressPos.x()
toY = fromY + mousePos.y() - self.mousePressPos.y()
diff.setX(toX - fromX)
diff.setY(toY - fromY)
boundingRect.setLeft(toX)
boundingRect.setBottom(toY)
rect.setLeft(boundingRect.left() + offset)
rect.setBottom(boundingRect.bottom() - offset)
self.setRect(rect)
elif self.handleSelected == self.handleBottomMiddle:
fromY = self.mousePressRect.bottom()
toY = fromY + mousePos.y() - self.mousePressPos.y()
diff.setY(toY - fromY)
boundingRect.setBottom(toY)
rect.setBottom(boundingRect.bottom() - offset)
self.setRect(rect)
elif self.handleSelected == self.handleBottomRight:
fromX = self.mousePressRect.right()
fromY = self.mousePressRect.bottom()
toX = fromX + mousePos.x() - self.mousePressPos.x()
toY = fromY + mousePos.y() - self.mousePressPos.y()
diff.setX(toX - fromX)
diff.setY(toY - fromY)
boundingRect.setRight(toX)
boundingRect.setBottom(toY)
rect.setRight(boundingRect.right() - offset)
rect.setBottom(boundingRect.bottom() - offset)
self.setRect(rect)
self.updateHandlesPos()
def shape(self):
"""返回Item的shape形状，并在local coordinates添加到QPainterPath上"""
path = QPainterPath()
path.addRect(self.rect())
if self.isSelected(): # 当该自定义图形类被选中时
for shape in self.handles.values(): # 在每个handles点上加上小圆圈
path.addEllipse(shape)
return path
def paint(self, painter, option, widget=None):
"""在Qgraphicview上绘制边框的选择小圆圈"""
point = QPointF(0, 0) # 插入的图片的左上角位置
self.w = self.rect().width()
self.h = self.rect().height()
self.pixfixed = self.pix.scaled(self.w,self.h)
painter.drawPixmap(point, self.pixfixed, self.rect())
painter.setRenderHint(QPainter.Antialiasing)
painter.setBrush(QBrush(QColor(255, 0, 0, 255)))
painter.setPen(QPen(QColor(0, 0, 0, 255), 1.0, Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin))
for shape in self.handles.values():
if self.isSelected():
painter.drawEllipse(shape)
def w_and_h_show(self):
pass
class RectHandle(QGraphicsRectItem): #QGraphicsRectItem
""" 自定义小handles的名称、序号、控制点位置"""
# handles 按照顺时针排列
handle_names = ('left_top', 'middle_top', 'right_top', 'right_middle',
'right_bottom', 'middle_bottom', 'left_bottom', 'left_middle')
# 设定在控制点上的光标形状
handle_cursors = {
0: Qt.SizeFDiagCursor,
1: Qt.SizeVerCursor,
2: Qt.SizeBDiagCursor,
3: Qt.SizeHorCursor,
4: Qt.SizeFDiagCursor,
5: Qt.SizeVerCursor,
6: Qt.SizeBDiagCursor,
7: Qt.SizeHorCursor
}
offset = 6.0 # 外边界框相对于内边界框的偏移量，也是控制点的大小
#min_size = 8 * offset # 矩形框的最小尺寸
def update_handles_pos(self):
"""
更新控制点的位置
"""
o = self.offset # 偏置量
s = o*2 # handle 的大小
b = self.rect() # 获取内边框
x1, y1 = b.left(), b.top() # 左上角坐标
offset_x = b.width()/2
offset_y = b.height()/2
# 设置 handles 的位置
self.handles[0] = QRectF(x1-o, y1-o, s, s)
self.handles[1] = self.handles[0].adjusted(offset_x, 0, offset_x, 0)
self.handles[2] = self.handles[1].adjusted(offset_x, 0, offset_x, 0)
self.handles[3] = self.handles[2].adjusted(0, offset_y, 0, offset_y)
self.handles[4] = self.handles[3].adjusted(0, offset_y, 0, offset_y)
self.handles[5] = self.handles[4].adjusted(-offset_x, 0, -offset_x, 0)
self.handles[6] = self.handles[5].adjusted(-offset_x, 0, -offset_x, 0)
self.handles[7] = self.handles[6].adjusted(0, -offset_y, 0, -offset_y)
class RectItem(RectHandle):
""" 自定义可变矩形类"""
def __init__(self, color,width,*args, **kwargs):
super().__init__(*args, **kwargs)
self.handles = {} # 控制点的字典
self.setAcceptHoverEvents(True) # 设定为接受 hover 事件
self.setFlags(QGraphicsItem.ItemIsSelectable | # 设定矩形框为可选择的
QGraphicsItem.ItemSendsGeometryChanges | # 追踪图元改变的信息
QGraphicsItem.ItemIsFocusable | # 可聚焦
QGraphicsItem.ItemIsMovable) # 可移动
self.update_handles_pos() # 初始化控制点
self.reset_Ui() # 初始化 UI 变量
self.pen_color=color
self.pen_width=width
def reset_Ui(self):
'''初始化 UI 变量'''
self.handleSelected = None # 被选中的控制点
self.mousePressPos = None # 鼠标按下的位置
#self.mousePressRect = None # 鼠标按下的位置所在的图元的外边界框
def boundingRect(self):
"""
限制图元的可视化区域，且防止出现图元移动留下残影的情况
"""
o = self.offset
# 添加一个间隔为 o 的外边框
return self.rect().adjusted(-o,-o,o,o)
def paint(self, painter, option, widget=None):
"""
Paint the node in the graphic view.
"""
# painter.setBrush(QBrush(QColor(255, 0, 0, 100)))
painter.setPen(QPen(self.pen_color, self.pen_width, Qt.SolidLine))
painter.drawRect(self.rect())
# painter.drawEllipse(self.rect())
painter.setRenderHint(QPainter.Antialiasing)
painter.setBrush(QBrush(QColor(255, 255, 0, 200)))
painter.setPen(QPen(QColor(0, 0, 0, 255), 0,
Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin))
for shape in self.handles.values():
if self.isSelected():
painter.drawEllipse(shape)
def handle_at(self, point):
"""
返回给定 point 下的控制点 handle
"""
for k, v, in self.handles.items():
if v.contains(point):
return k
return
def hoverMoveEvent(self, event):
"""
当鼠标移到该 item（未按下）上时执行。
"""
super().hoverMoveEvent(event)
handle = self.handle_at(event.pos())
cursor = self.handle_cursors[handle] if handle in self.handles else Qt.ArrowCursor
self.setCursor(cursor)
def hoverLeaveEvent(self, event):
"""
当鼠标离开该形状（未按下）上时执行。
"""
super().hoverLeaveEvent(event)
self.setCursor(Qt.ArrowCursor) # 设定鼠标光标形状
def mousePressEvent(self, event):
"""
当在 item 上按下鼠标时执行。
"""
super().mousePressEvent(event)
self.handleSelected = self.handle_at(event.pos())
if self.handleSelected in self.handles:
self.mousePressPos = event.pos()
def mouseReleaseEvent(self, event):
"""
Executed when the mouse is released from the item.
"""
super().mouseReleaseEvent(event)
self.update()
self.reset_Ui()
def mouseMoveEvent(self, event):
"""
Executed when the mouse is being moved over the item while being pressed.
"""
if self.handleSelected in self.handles:
self.interactiveResize(event.pos())
else:
super().mouseMoveEvent(event)
def interactiveResize(self, mousePos):
"""
Perform shape interactive resize.
"""
rect = self.rect()
self.prepareGeometryChange()
# movePos = mousePos - self.mousePressPos
# move_x, move_y = movePos.x(), movePos.y()
if self.handleSelected == 0:
rect.setTopLeft(mousePos)
elif self.handleSelected == 1:
rect.setTop(mousePos.y())
elif self.handleSelected == 2:
rect.setTopRight(mousePos)
elif self.handleSelected == 3:
rect.setRight(mousePos.x())
elif self.handleSelected == 4:
rect.setBottomRight(mousePos)
elif self.handleSelected == 5:
rect.setBottom(mousePos.y())
elif self.handleSelected == 6:
rect.setBottomLeft(mousePos)
elif self.handleSelected == 7:
rect.setLeft(mousePos.x())
self.setRect(rect)
self.update_handles_pos()
class EllipseItem(RectHandle):
""" 自定义可变椭圆类"""
def __init__(self, color,width,*args, **kwargs):
super().__init__(*args, **kwargs)
self.handles = {} # 控制点的字典
self.setAcceptHoverEvents(True) # 设定为接受 hover 事件
self.setFlags(QGraphicsItem.ItemIsSelectable | # 设定矩形框为可选择的
QGraphicsItem.ItemSendsGeometryChanges | # 追踪图元改变的信息
QGraphicsItem.ItemIsFocusable | # 可聚焦
QGraphicsItem.ItemIsMovable) # 可移动
self.update_handles_pos() # 初始化控制点
self.reset_Ui() # 初始化 UI 变量
self.pen_color=color
self.pen_width=width
def reset_Ui(self):
'''初始化 UI 变量'''
self.handleSelected = None # 被选中的控制点
self.mousePressPos = None # 鼠标按下的位置
#self.mousePressRect = None # 鼠标按下的位置所在的图元的外边界框
def boundingRect(self):
"""
限制图元的可视化区域，且防止出现图元移动留下残影的情况
"""
o = self.offset
# 添加一个间隔为 o 的外边框
return self.rect().adjusted(-o, -o, o, o)
def paint(self, painter, option, widget=None):
"""
Paint the node in the graphic view.
"""
# painter.setBrush(QBrush(QColor(255, 0, 0, 100)))
painter.setPen(QPen(self.pen_color, self.pen_width, Qt.SolidLine))
# painter.drawRect(self.rect())
painter.drawEllipse(self.rect())
painter.setRenderHint(QPainter.Antialiasing)
painter.setBrush(QBrush(QColor(255, 255, 0, 200)))
painter.setPen(QPen(QColor(0, 0, 0, 255), 0,
Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin))
for shape in self.handles.values():
if self.isSelected():
painter.drawEllipse(shape)
def handle_at(self, point):
"""
返回给定 point 下的控制点 handle
"""
for k, v, in self.handles.items():
if v.contains(point):
return k
return
def hoverMoveEvent(self, event):
"""
当鼠标移到该 item（未按下）上时执行。
"""
super().hoverMoveEvent(event)
handle = self.handle_at(event.pos())
cursor = self.handle_cursors[handle] if handle in self.handles else Qt.ArrowCursor
self.setCursor(cursor)
def hoverLeaveEvent(self, event):
"""
当鼠标离开该形状（未按下）上时执行。
"""
super().hoverLeaveEvent(event)
self.setCursor(Qt.ArrowCursor) # 设定鼠标光标形状
def mousePressEvent(self, event):
"""
当在 item 上按下鼠标时执行。
"""
super().mousePressEvent(event)
self.handleSelected = self.handle_at(event.pos())
if self.handleSelected in self.handles:
self.mousePressPos = event.pos()
def mouseReleaseEvent(self, event):
"""
Executed when the mouse is released from the item.
"""
super().mouseReleaseEvent(event)
self.update()
self.reset_Ui()
def mouseMoveEvent(self, event):
"""
Executed when the mouse is being moved over the item while being pressed.
"""
if self.handleSelected in self.handles:
self.interactiveResize(event.pos())
else:
super().mouseMoveEvent(event)
def interactiveResize(self, mousePos):
"""
Perform shape interactive resize.
"""
rect = self.rect()
self.prepareGeometryChange()
# movePos = mousePos - self.mousePressPos
# move_x, move_y = movePos.x(), movePos.y()
if self.handleSelected == 0:
rect.setTopLeft(mousePos)
elif self.handleSelected == 1:
rect.setTop(mousePos.y())
elif self.handleSelected == 2:
rect.setTopRight(mousePos)
elif self.handleSelected == 3:
rect.setRight(mousePos.x())
elif self.handleSelected == 4:
rect.setBottomRight(mousePos)
elif self.handleSelected == 5:
rect.setBottom(mousePos.y())
elif self.handleSelected == 6:
rect.setBottomLeft(mousePos)
elif self.handleSelected == 7:
rect.setLeft(mousePos.x())
self.setRect(rect)
self.update_handles_pos()
class Arrow(QGraphicsPathItem):
""" 自定义箭头类，类重写的是QGraphicsPathItem"""
def __init__(self, scene, color, penwidth, parent=None):
super().__init__(parent)
self.pen_color = color # 从Qgraphicsview导入笔的颜色
self.pen_width = penwidth # 从Qgraphicsview导入笔的宽度
self.scene = scene #从Qgraphicsview导入Myscene()这个场景，并设置为它
self.pos_src = [0, 0]
self.pos_dst = [0, 0]
self.setFlags(QGraphicsItem.ItemIsSelectable | # 设定矩形框为可选择的
QGraphicsItem.ItemSendsGeometryChanges | # 追踪图元改变的信息
QGraphicsItem.ItemIsFocusable | # 可聚焦
QGraphicsItem.ItemIsMovable) # 可移动
def set_src(self, x, y):
self.pos_src = [x, y]
def set_dst(self, x, y):
self.pos_dst = [x, y]
def calc_path(self):
path = QPainterPath(QPointF(self.pos_src[0], self.pos_src[1]))
path.lineTo(self.pos_dst[0], self.pos_dst[1])
return path
def boundingRect(self):
o=self.offset=self.pen_width*10
x1, y1 = self.pos_src
x2=self.shape().boundingRect().width()
y2=self.shape().boundingRect().height()
self.QF=QRectF(x1,y1,x2,y2)
return self.shape().boundingRect().adjusted(-o, -o, o, o)
# return self.QF.adjusted(-o,-o,o,o)
def shape(self):
return self.calc_path()
def paint(self, painter, option, widget=None):
self.setPath(self.calc_path())
path = self.path()
painter.setPen(QPen(self.pen_color, self.pen_width, Qt.SolidLine))
painter.drawPath(path)
x1, y1 = self.pos_src
x2, y2 = self.pos_dst
self.source = QPointF(x1, y1)
self.dest = QPointF(x2, y2)
self.line = QLineF(self.source, self.dest)
# 设置垂直向量
v = self.line.unitVector()
v.setLength(self.pen_width*4)
v.translate(QPointF(self.line.dx(), self.line.dy()))
# 设置水平向量
n = v.normalVector()
n.setLength(n.length() * 0.5)
n2 = n.normalVector().normalVector()
# 设置箭头三角形的三个点
p1 = v.p2()
p2 = n.p2()
p3 = n2.p2()
# 以下用于绘制箭头，外边框粗为1.0
painter.setPen(QPen(self.pen_color, 1.0, Qt.SolidLine))
painter.setBrush(self.pen_color)
painter.drawPolygon(p1, p2, p3)
class TextItemDlg(QDialog):
""" 自定义文本类所用到的窗口，用的是类似Qwidget"""
def __init__(self, item=None, position=None, scene=None, parent=None):
super(QDialog, self).__init__(parent)
try:
self.item = item
self.position = position
self.scene = scene
self.font = None
self.background_color_str="white"
self.booltext = False
self.editor = QTextEdit()
self.editor.setAcceptRichText(False)
self.editor.setTabChangesFocus(True)
editorLabel = QLabel("文字输入框:")
editorLabel.setBuddy(self.editor)
self.fontComboBox = QFontComboBox()
self.fontComboBox.setCurrentFont(QFont("Times", PointSize))
fontLabel = QLabel("&字体：")
fontLabel.setBuddy(self.fontComboBox)
self.fontSpinBox = QSpinBox()
self.fontSpinBox.setAlignment(Qt.AlignRight| Qt.AlignVCenter)
self.fontSpinBox.setRange(5, 300)
self.fontSpinBox.setValue(PointSize)
fontSizeLabel = QLabel("&字体大小：")
fontSizeLabel.setBuddy(self.fontSpinBox)
self.buttonBox = QDialogButtonBox(QDialogButtonBox.Ok| QDialogButtonBox.Cancel)
self.buttonBox.button(QDialogButtonBox.Ok).setEnabled(False)
self.textcolorlabel=QLabel("字体颜色：")
self.textcolor=QComboBox()
self.backgroundcolorlabel=QLabel("文本框颜色:")
self.backgroundcolorlabel.setAlignment(Qt.AlignRight| Qt.AlignVCenter)
self.backgroundcolor=QComboBox()
# 获取颜色列表(字符串类型)
self.__colorList = QColor.colorNames()
# 用各种颜色填充下拉列表
self.__fillColorList(self.textcolor)
self.__fillColorList1(self.backgroundcolor)
self.bold_btn=QPushButton("B/加粗")
self.bold_btn.setCheckable(True)
self.Italic_btn=QPushButton("I/斜体")
self.Italic_btn.setCheckable(True)
self.underline_btn=QPushButton("U/下划线")
self.underline_btn.setCheckable(True)
if self.item is not None:
self.editor.setPlainText(self.item.toPlainText())
self.fontComboBox.setCurrentFont(self.item.font())
self.fontSpinBox.setValue(self.item.font().pointSize())
layout = QGridLayout()
layout.addWidget(editorLabel, 0, 0)
layout.addWidget(self.bold_btn,0,1)
layout.addWidget(self.Italic_btn,0,2)
layout.addWidget(self.underline_btn, 0, 3)
layout.addWidget(self.editor, 1, 0, 1, 6)
layout.addWidget(fontLabel, 2, 0)
layout.addWidget(self.fontComboBox, 2, 1, 1, 2)
layout.addWidget(fontSizeLabel, 2, 3)
layout.addWidget(self.fontSpinBox, 2, 4, 1, 2)
layout.addWidget(self.buttonBox, 4, 0, 1, 6)
layout.addWidget(self.textcolor,3,1,1,1)
layout.addWidget(self.textcolorlabel,3,0)
layout.addWidget(self.backgroundcolorlabel,3,2)
layout.addWidget(self.backgroundcolor,3,3,1,1)
self.setLayout(layout)
self.fontComboBox.currentFontChanged.connect(self.updateUi)
self.fontSpinBox.valueChanged.connect(self.updateUi)
self.editor.textChanged.connect(self.updateUi)
self.buttonBox.accepted.connect(self.accept)
self.buttonBox.rejected.connect(self.reject)
# self.textcolor.currentIndexChanged.connect(self.on_textcolorChange)
self.textcolor.currentIndexChanged.connect(self.updateUi)
self.backgroundcolor.currentIndexChanged.connect(self.on_backgroundcolorChange)
self.setWindowTitle("添加文本")
self.setWindowIcon(QIcon("q.ico"))
self.updateUi()
self.bold_btn.clicked.connect(self.on_bold_btn_clicked)
except Exception as e:
print(e)
def on_bold_btn_clicked(self):
self.booltext=self.bold_btn.isChecked()
def on_textcolorChange(self):
self.color_index = self.textcolor.currentIndex()
self.color_str = self.__colorList[self.color_index]
def on_backgroundcolorChange(self):
self.background_color_index=self.backgroundcolor.currentIndex()
self.background_color_str=self.__colorList[self.background_color_index]
def __fillColorList(self, comboBox):
index_red = 0
index = 0
for color in self.__colorList:
if color == "red":
index_red = index
index += 1
pix = QPixmap(120, 30)
pix.fill(QColor(color))
comboBox.addItem(QIcon(pix), None)
comboBox.setIconSize(QSize(100, 20))
comboBox.setSizeAdjustPolicy(QComboBox.AdjustToContents)
comboBox.setCurrentIndex(index_red)
def __fillColorList1(self, comboBox):
index_white = 0
index = 0
for color in self.__colorList:
if color == "white":
index_white = index
index += 1
pix = QPixmap(120, 30)
pix.fill(QColor(color))
comboBox.addItem(QIcon(pix), None)
comboBox.setIconSize(QSize(100, 20))
comboBox.setSizeAdjustPolicy(QComboBox.AdjustToContents)
comboBox.setCurrentIndex(index_white)
def updateUi(self):
try:
self.font = self.fontComboBox.currentFont()
self.font.setPointSize(self.fontSpinBox.value())
self.editor.document().setDefaultFont(self.font)
self.color_index = self.textcolor.currentIndex()
self.color_str = self.__colorList[self.color_index]
pl=QPalette()
pl.setColor(QPalette.Text,QColor(self.color_str))
self.editor.setPalette(pl)
self.buttonBox.button(QDialogButtonBox.Ok).setEnabled(bool(self.editor.toPlainText()))
self.font.setBold(self.booltext)
except Exception as e:
print(e)
def accept(self):
try:
if self.item is None:
self.item = TextItem("", self.position, self.scene)
self.font = self.fontComboBox.currentFont()
self.font.setPointSize(self.fontSpinBox.value())
self.item.setFont(self.font)
text='<span style="background:'+self.background_color_str+';"><font color="'+self.color_str+'">'+self.editor.toPlainText()+'</font></span>'
# 测试是否有换行符
# for i,t in enumerate(text):
# if t=="\n":
# print("y")
# t="<br/>"
text_fixed=text.replace("\n","<br/>")
print(text_fixed)
self.item.setHtml(text_fixed)
QDialog.accept(self)
except Exception as e:
print(e)
PointSize = 15
class TextItem(QGraphicsTextItem):
""" 自定义文本类"""
def __init__(self, text, position, scene,
font=QFont("宋体", PointSize)):
super(TextItem, self).__init__(text)
try:
self.setFlags(QtWidgets.QGraphicsItem.ItemIsSelectable
| QtWidgets.QGraphicsItem.ItemIsMovable
| QtWidgets.QGraphicsItem.ItemIsFocusable
| QtWidgets.QGraphicsItem.ItemSendsGeometryChanges
| QtWidgets.QGraphicsItem.ItemSendsScenePositionChanges)
self.setFont(font)
self.setDefaultTextColor(Qt.red)
self.setPos(position)
scene.clearSelection()
scene.addItem(self)
self.setSelected(True)
except Exception as e:
print(e)
def parentWidget(self):
try:
return self.scene().views()[0]
except Exception as e:
print(e)
def mouseDoubleClickEvent(self, event):
dialog = TextItemDlg(self, self.parentWidget())
dialog.exec_()
# 画板弹窗界面
class PaintBoard1(QWidget, painter):
def __init__(self):
super(QWidget,self).__init__()
self.setupUi(self)
self.graphics = GraphicView()
self.scene = self.graphics.scene
self.graphics.setAlignment(Qt.AlignLeft | Qt.AlignTop)
# 千万记得用addWidget(self.graphics)，而不是addWidget(addWidget)，不然传参数会有问题
self.gridLayout_paintbox.addWidget(self.graphics)
self.pix = None
self.pixfixed = None
self.pw = None
self.ph = None
# 获取颜色列表(字符串类型)
self.__colorList = QColor.colorNames()
# 用各种颜色填充下拉列表
self.__fillColorList(self.comboBox_penColor)
# 下拉菜单改变画笔颜色
# 关联下拉列表的当前索引变更信号与函数on_PenColorChange
self.comboBox_penColor.currentIndexChanged.connect(self.on_PenColorChange)
# 设置画笔粗细大小
self.Pen_Thickness.setMaximum(50)
self.Pen_Thickness.setMinimum(0)
self.Pen_Thickness.setValue(5)
self.Pen_Thickness.setSingleStep(1)
# 关联spinBox值变化信号和函数on_PenThicknessChange
self.Pen_Thickness.valueChanged.connect(self.on_PenThicknessChange)
# 信号与槽
self.Openfile_btn.clicked.connect(self.on_btn_Open_Clicked)
self.Quit_btn.clicked.connect(self.on_btn_Quit_Clicked)
self.Clear_btn.clicked.connect(self.clean_all)
# self.Eraser_cbtn.clicked.connect(self.on_cbtn_Eraser_clicked)
self.Save_btn.clicked.connect(self.on_btn_Save_Clicked)
self.circle_btn.clicked.connect(self.on_circle_btn_clicked)
self.Free_pen_btn.clicked.connect(self.on_Free_pen_btn_clicked)
self.line_btn.clicked.connect(self.line_btn_clicked)
self.rect_btn.clicked.connect(self.on_rect_btn_clicked)
self.text_btn.clicked.connect(self.addText)
self.pic_move_btn.clicked.connect(self.on_pic_move_btn_clicked)
self.drawback_btn.clicked.connect(self.drawback)
self.set_upper_btn.clicked.connect(self.item_up)
self.set_lower_btn.clicked.connect(self.item_down)
self.test.clicked.connect(self.item_rect_change)
def line_btn_clicked(self,*type):
type = "line"
self.graphics.Shape(type)
def wc(self,w):
self.w=w
print(self.w)
self.strw=str(int(self.w))
self.wid=QLabel()
self.wid.setText(self.strw)
self.gridLayout_paintbox.addWidget(self.wid)
def wh_change(self,w,h):
try:
self.w=w
self.h=h
print(self.w,self.h)
except Exception as e:
print(e)
# 记录鼠标选择的items
def selectedItem(self):
items = self.scene.selectedItems()
if len(items) == 1:
return items[0]
return None
def item_rect_change(self):
item=self.selectedItem()
if item==None:
pass
else:
width=item.boundingRect().width()
height=item.boundingRect().height()
self.width_value.setText(str(int(width)))
self.height_value.setText(str(int(height)))
self.scene.addItem(Rectangle(200, 150, 100, 100))
# 上移一层
def item_up(self):
try:
if self.selectedItem()==None:
print("no item selected")
# item=self.scene.itemAt(self.point)
else:
z= self.selectedItem().zValue()
self.selectedItem().setZValue(z+1)
except Exception as e:
print(e)
# 下移一层
def item_down(self):
try:
if self.selectedItem()==None:
print("no item selected")
else:
z= self.selectedItem().zValue()
self.selectedItem().setZValue(z-1)
except Exception as e:
print(e)
# 撤销上一个绘图的图元
def drawback(self,*item):
try:
items = self.scene.items()
item = items[0]
print(item)
self.scene.removeItem(item)
except Exception as e:
print(e)
# 设置图片移动
def on_pic_move_btn_clicked(self,*type):
type = "move"
self.graphics.Shape(type)
self.scene.clearSelection()
# 添加文本
def addText(self):
try:
dialog = TextItemDlg(position=QPoint(200, 200),
scene=self.scene, parent=None)
dialog.exec_()
except Exception as e:
print(e)
def on_Scene_size_clicked(self):
w=self.scene.width()
h=self.scene.height()
p=self.width()
q=self.height()
s=self.size()
def on_Free_pen_btn_clicked(self, *shape):
shape = "Free pen"
self.graphics.Shape(shape)
# 设置画圆圈
def on_circle_btn_clicked(self, *shape): # 注意传入参数为文字时，为*加上变量，即“*变量”
try:
shape = "circle"
self.graphics.Shape(shape)
except Exception as e:
print(e)
def on_rect_btn_clicked(self, *shape):
shape ="rect"
self.graphics.Shape(shape)
# 打开图片功能
def on_btn_Open_Clicked(self):
try:
openPath = QFileDialog.getOpenFileName(self, '打开图片', '.\\', '*.png;*.jpg')
# print(openPath)
if openPath[0] == "":
print("已取消")
return
filename = openPath[0]
# print(filename)
self.pix = QPixmap()
self.pix.load(filename)
# print(self.pix.width(),self.pix.height())
# 对于图片长宽超过800,600的，缩放后完全显示
self.pixfixed = self.pix.scaled(600, 600,Qt.KeepAspectRatio,Qt.SmoothTransformation)
# self.scene.addPixmap(self.pixfixed)
# print(self.pixfixed.width(),self.pixfixed.height())
item1=PItem(filename,0,0,600,500)
self.scene.addItem(item1)
item=QGraphicsPixmapItem(self.pixfixed)
# item.setFlag(QGraphicsItem.ItemIsSelectable)
item.setFlag(QGraphicsItem.ItemIsMovable)
item.setZValue(-1)
# self.pixrect=item.boundingRect()
# self.scene.addItem(item)
self.pw = self.pixfixed.width()
self.ph = self.pixfixed.height()
except Exception as e:
print(e)
# 退出画板主窗口
def on_btn_Quit_Clicked(self):
self.close()
# 图片保存功能
def on_btn_Save_Clicked(self):
try:
savePath = QFileDialog.getSaveFileName(self, '保存图片', '.\\', '*.jpg;*.png')
if savePath[0] == "":
print("取消保存")
return
# pm=QPixmap(self.pixfixed.width(), self.pixfixed.height())
pm = QPixmap(600, 500) # 注意，设置画布的大小为Myscene的大小，下边保存时才不会产生黑边
pm.fill(Qt.white) # 当区域没有Item时，保存图片不产生黑色区域
# 设置绘图工具
painter1 = QPainter(pm)
painter1.setRenderHint(QPainter.Antialiasing)
painter1.setRenderHint(QPainter.SmoothPixmapTransform)
# 使打印长和宽与导入的Pixmap图片长宽匹配，不会产生黑边
# self.graphics.render(painter1,QRectF(0,0,self.pixfixed.width(),self.pixfixed.height()),QRect(0,0,self.pixfixed.width(),self.pixfixed.height()))
# 注意，大小设置与Myscene的大小一致，画布大小一致时，才真的不会产生黑边
self.graphics.render(painter1, QRectF(0, 0, 600, 500),QRect(0,0,600,500))
# QRect(0, 0, 600, 500))
painter1.end()
pm.save(savePath[0])
except Exception as e:
print(e)
# combobox填充颜色序列
def __fillColorList(self, comboBox):
index_red = 0
index = 0
for color in self.__colorList:
if color == "red":
index_red = index
index += 1
pix = QPixmap(120, 30)
pix.fill(QColor(color))
comboBox.addItem(QIcon(pix), None)
comboBox.setIconSize(QSize(100, 20))
comboBox.setSizeAdjustPolicy(QComboBox.AdjustToContents)
comboBox.setCurrentIndex(index_red)
# 画笔颜色更改
def on_PenColorChange(self):
color_index = self.comboBox_penColor.currentIndex()
color_str = self.__colorList[color_index]
self.graphics.ChangePenColor(color_str)
# 画笔粗细调整
def on_PenThicknessChange(self):
penThickness = self.Pen_Thickness.value()
self.graphics.ChangePenThickness(penThickness)
# 设置鼠标Qcursor指标为画笔图片
# pm = QPixmap('pen.ico')
# l= self.Pen_Thickness.value()
# if l<=10:
# l=10
# pm = pm.scaled(l, l, Qt.KeepAspectRatio)
# cursor = QCursor(pm)
# self.setCursor(cursor)
# 橡皮擦粗细调整
def on_EraserThicknessChange(self):
EraserThickness = self.Eraser_thickness.value()
self.scene.ChangeEraserThickness(EraserThickness)
pm = QPixmap('circle.ico')
r = self.Eraser_thickness.value()
pm = pm.scaled(r, r, Qt.KeepAspectRatio)
cursor = QCursor(pm)
self.setCursor(cursor)
# 清除图元
def clean_all(self):
try:
self.scene.clear()
except Exception as e:
print(e)
class Rectangle(QtWidgets.QGraphicsRectItem):
""" 自定义可变矩形类，采用鼠标中键动态设置矩形大小"""
def __init__(self, x, y, w, h):
super(Rectangle, self).__init__(0, 0, w, h)
self.setPen(QPen(Qt.red, 5))
self.setFlags(QtWidgets.QGraphicsItem.ItemIsSelectable
| QtWidgets.QGraphicsItem.ItemIsMovable
| QtWidgets.QGraphicsItem.ItemIsFocusable
| QtWidgets.QGraphicsItem.ItemSendsGeometryChanges
| QtWidgets.QGraphicsItem.ItemSendsScenePositionChanges)
self.setPos(QPointF(x, y))
self.setZValue(1)
def mouseMoveEvent(self, e):
# print(self.x,self.y)
if e.buttons() & Qt.LeftButton:
super(Rectangle, self).mouseMoveEvent(e)
if e.buttons() & Qt.MidButton:
self.setRect(QRectF(QPoint(), e.pos()).normalized())