Corrected mouse clicking on PlotCurveItem - now uses stroke outline instead of path shape

Added 'width' argument to PlotCurveItem.setClickable()

examples/MouseSelection.py

@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+"""
+Demonstrates selecting plot curves by mouse click
+"""
+import initExample ## Add path to library (just for examples; you do not need this)
+
+import pyqtgraph as pg
+from pyqtgraph.Qt import QtCore, QtGui
+import numpy as np
+
+win = pg.plot()
+win.setWindowTitle('pyqtgraph example: Plot data selection')
+
+curves = [
+    pg.PlotCurveItem(y=np.sin(np.linspace(0, 20, 1000)), pen='r', clickable=True),
+    pg.PlotCurveItem(y=np.sin(np.linspace(1, 21, 1000)), pen='g', clickable=True),
+    pg.PlotCurveItem(y=np.sin(np.linspace(2, 22, 1000)), pen='b', clickable=True),
+    ]
+              
+def plotClicked(curve):
+    global curves
+    for i,c in enumerate(curves):
+        if c is curve:
+            c.setPen('rgb'[i], width=3)
+        else:
+            c.setPen('rgb'[i], width=1)
+            
+    
+for c in curves:
+    win.addItem(c)
+    c.sigClicked.connect(plotClicked)
+
+## Start Qt event loop unless running in interactive mode or using pyside.
+if __name__ == '__main__':
+    import sys
+    if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
+        QtGui.QApplication.instance().exec_()

pyqtgraph/graphicsItems/PlotCurveItem.py

@@ -53,9 +53,6 @@ class PlotCurveItem(GraphicsObject):
         """
         GraphicsObject.__init__(self, kargs.get('parent', None))
         self.clear()
-        self.path = None
-        self.fillPath = None
-        self._boundsCache = [None, None]
             
         ## this is disastrous for performance.
         #self.setCacheMode(QtGui.QGraphicsItem.DeviceCoordinateCache)
@@ -70,6 +67,7 @@ class PlotCurveItem(GraphicsObject):
             'name': None,
             'antialias': pg.getConfigOption('antialias'),\
             'connect': 'all',
+            'mouseWidth': 8, # width of shape responding to mouse click
         }
         self.setClickable(kargs.get('clickable', False))
         self.setData(*args, **kargs)
@@ -80,9 +78,17 @@ class PlotCurveItem(GraphicsObject):
             return ints
         return interface in ints
     
-    def setClickable(self, s):
+    def setClickable(self, s, width=None):
-        """Sets whether the item responds to mouse clicks."""
+        """Sets whether the item responds to mouse clicks.
+        
+        The *width* argument specifies the width in pixels orthogonal to the
+        curve that will respond to a mouse click.
+        """
         self.clickable = s
+        if width is not None:
+            self.opts['mouseWidth'] = width
+            self._mouseShape = None
+            self._boundingRect = None        
         
         
     def getData(self):
@@ -148,6 +154,8 @@ class PlotCurveItem(GraphicsObject):
             w += pen.widthF()*0.7072
         if spen is not None and spen.isCosmetic() and spen.style() != QtCore.Qt.NoPen:
             w = max(w, spen.widthF()*0.7072)
+        if self.clickable:
+            w = max(w, self.opts['mouseWidth']//2 + 1)
         return w
 
     def boundingRect(self):
@@ -171,6 +179,7 @@ class PlotCurveItem(GraphicsObject):
             #px += self._maxSpotWidth * 0.5
             #py += self._maxSpotWidth * 0.5
             self._boundingRect = QtCore.QRectF(xmn-px, ymn-py, (2*px)+xmx-xmn, (2*py)+ymx-ymn)
+            
         return self._boundingRect
     
     def viewTransformChanged(self):
@@ -328,6 +337,7 @@ class PlotCurveItem(GraphicsObject):
         
         self.path = None
         self.fillPath = None
+        self._mouseShape = None
         #self.xDisp = self.yDisp = None
         
         if 'name' in kargs:
@@ -376,12 +386,14 @@ class PlotCurveItem(GraphicsObject):
         return path
 
 
-    def shape(self):
+    def getPath(self):
         if self.path is None:
-            try:
+            x,y = self.getData()
-                self.path = self.generatePath(*self.getData())
+            if x is None or len(x) == 0 or y is None or len(y) == 0:
-            except:
                 return QtGui.QPainterPath()
+            self.path = self.generatePath(*self.getData())
+            self.fillPath = None
+            self._mouseShape = None
         return self.path
 
     @pg.debug.warnOnException  ## raising an exception here causes crash
@@ -396,14 +408,8 @@ class PlotCurveItem(GraphicsObject):
         
         x = None
         y = None
-        if self.path is None:
+        path = self.getPath()
-            x,y = self.getData()
+        
-            if x is None or len(x) == 0 or y is None or len(y) == 0:
-                return
-            self.path = self.generatePath(x,y)
-            self.fillPath = None
-            
-        path = self.path
         profiler('generate path')
         
         if self._exportOpts is not False:
@@ -522,13 +528,36 @@ class PlotCurveItem(GraphicsObject):
         self.xDisp = None  ## display values (after log / fft)
         self.yDisp = None
         self.path = None
+        self.fillPath = None
+        self._mouseShape = None
+        self._mouseBounds = None
+        self._boundsCache = [None, None]
         #del self.xData, self.yData, self.xDisp, self.yDisp, self.path
+
+    def mouseShape(self):
+        """
+        Return a QPainterPath representing the clickable shape of the curve
+        
+        """
+        if self._mouseShape is None:
+            view = self.getViewBox()
+            if view is None:
+                return QtGui.QPainterPath()
+            stroker = QtGui.QPainterPathStroker()
+            path = self.getPath()
+            path = self.mapToItem(view, path)
+            stroker.setWidth(self.opts['mouseWidth'])
+            mousePath = stroker.createStroke(path)
+            self._mouseShape = self.mapFromItem(view, mousePath)
+        return self._mouseShape
         
     def mouseClickEvent(self, ev):
         if not self.clickable or ev.button() != QtCore.Qt.LeftButton:
             return
-        ev.accept()
+        if self.mouseShape().contains(ev.pos()):
-        self.sigClicked.emit(self)
+            ev.accept()
+            self.sigClicked.emit(self)
+            
 
 
 class ROIPlotItem(PlotCurveItem):