Question

我的应用程序与以下问题非常相似：Draw half infinite lines?

我想拥有一个具有多个阈值的无限线。

问题中提供的解决方案是一个很好的起点：https://stackoverflow.com/a/37836348/7163293

我尝试通过修改movable中的__init__属性并在源代码中添加setMovable方法来使行可移动：

http://www.pyqtgraph.org/documentation/_modules/pyqtgraph/graphicsItems/InfiniteLine.html#InfiniteLine

from pyqtgraph.Qt import QtGui
import numpy as np
import pyqtgraph as pg

class InfiniteLineWithBreak(pg.GraphicsObject):

    def __init__(self, changeX, levelsY, pen=None):
        pg.GraphicsObject.__init__(self)

        self.changeX = changeX
        self.levelsY = levelsY

        self.maxRange = [None, None]
        self.moving = False
        self.movable = True
        self.setMovable(self.movable)
        self.mouseHovering = False

        pen = (200, 200, 100)
        self.setPen(pen)
        self.setHoverPen(color=(255,0,0), width=self.pen.width())
        self.currentPen = self.pen

    def setMovable(self, m):
        """Set whether the line is movable by the user."""
        self.movable = m
        self.setAcceptHoverEvents(m)


    def setBounds(self, bounds):
        self.maxRange = bounds
        self.setValue(self.value())

    def setPen(self, *args, **kwargs):
        self.pen = pg.fn.mkPen(*args, **kwargs)
        if not self.mouseHovering:
            self.currentPen = self.pen
            self.update()

    def setHoverPen(self, *args, **kwargs):
        self.hoverPen = pg.fn.mkPen(*args, **kwargs)
        if self.mouseHovering:
            self.currentPen = self.hoverPen
            self.update()

    def boundingRect(self):
        br = self.viewRect()
        return br.normalized()

    def paint(self, p, *args):
        br = self.boundingRect()
        p.setPen(self.currentPen)
        # three lines (left border to change point, change point vertical, change point to right)
        p.drawLine(pg.Point(br.left(), self.levelsY[0]), pg.Point(self.changeX, self.levelsY[0]))
        p.drawLine(pg.Point(self.changeX, self.levelsY[0]), pg.Point(self.changeX, self.levelsY[1]))
        p.drawLine(pg.Point(self.changeX, self.levelsY[1]), pg.Point(br.right(), self.levelsY[1]))

    def dataBounds(self, axis, frac=1.0, orthoRange=None):
        if axis == 0:
            return None   ## x axis should never be auto-scaled
        else:
            return (0,0)

    def setMouseHover(self, hover):
        pass

app = QtGui.QApplication([])
w = pg.GraphicsWindow()
w.resize(1000, 600)
v = w.addPlot(y=np.random.normal(size=100))
v.addItem(InfiniteLineWithBreak(changeX=50, levelsY=(-1, 1)))
app.exec_()

然而，修改后线仍然不能移动。所以我有点被困在这里。有人能提供一些指示吗？

另外，理想情况下，应用程序上的行应按段移动。因此，当用户拖动一条线时，只有断点之间的部分在移动。理想情况下，我希望有类似的东西：

Draggable line with draggable points

在我的申请中。理想情况下它看起来像

阈值点水平（TH_Px_L1）可拖动但不是时间（TH_Px_T1），因此这些点只能垂直移动。

如果有人也可以提供第二项帮助，并提供一些非常有帮助的指示或解决方案。

Answer 1

基于文档中的this example。

散点图类型与绘制图形的图形类似，但是连接线位于i点点和它们连接的i + 1点点之间。然后我们将运动仅限制在垂直轴上，因为这是作者的要求。

import numpy as np
import pyqtgraph as pg
from pyqtgraph.Qt import QtCore, QtGui

pg.setConfigOptions(antialias=True)

w = pg.GraphicsWindow()
w.setWindowTitle('Draggable')


class Graph(pg.GraphItem):
    def __init__(self):
        self.dragPoint = None
        self.dragOffset = None
        pg.GraphItem.__init__(self)

    def setData(self, **kwds):
        self.data = kwds
        if 'pos' in self.data:
            npts = self.data['pos'].shape[0]
            self.data['adj'] = np.column_stack((np.arange(0, npts-1), np.arange(1, npts)))
            self.data['data'] = np.empty(npts, dtype=[('index', int)])
            self.data['data']['index'] = np.arange(npts)
        self.updateGraph()

    def updateGraph(self):
        pg.GraphItem.setData(self, **self.data)

    def mouseDragEvent(self, ev):
        if ev.button() != QtCore.Qt.LeftButton:
            ev.ignore()
            return

        if ev.isStart():
            pos = ev.buttonDownPos()
            pts = self.scatter.pointsAt(pos)
            if len(pts) == 0:
                ev.ignore()
                return
            self.dragPoint = pts[0]
            ind = pts[0].data()[0]
            self.dragOffset = self.data['pos'][ind][1] - pos[1]
        elif ev.isFinish():
            self.dragPoint = None
            return
        else:
            if self.dragPoint is None:
                ev.ignore()
                return

        ind = self.dragPoint.data()[0]
        self.data['pos'][ind][1] = ev.pos()[1] + self.dragOffset
        self.updateGraph()
        ev.accept()


g = Graph()
v = w.addPlot()
v.addItem(g)

x = np.linspace(1, 100, 40)
pos = np.column_stack((x, np.sin(x)))

g.setData(pos=pos, size=10, pxMode=True)

if __name__ == '__main__':
    import sys

    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
        QtGui.QApplication.instance().exec_()

具有多个断点的PyQt可拖动线

1 个答案: