commit patch 1599876, fixes to qt4agg backend and qt4 blitting demo.

ddale · ddale · commit 3c83fac65034 · 2007-11-02T16:37:37.000Z
Thanks to Phil Thompson.

svn path=/trunk/matplotlib/; revision=4096
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,3 +1,6 @@
+2007-11-02 Commited Phil Thompson's patch 1599876, fixes to Qt4Agg 
+           backend and qt4 blitting demo - DSD 
+
 2007-10-31 Made log color scale easier to use with contourf;
            automatic level generation now works. - EF
 
diff --git a/examples/animation_blit_qt4.py b/examples/animation_blit_qt4.py
@@ -15,20 +15,29 @@
 
 class BlitQT(QtCore.QObject):
     def __init__(self):
-        QtCore.QObject.__init__(self, None)
-
         self.ax = p.subplot(111)
         self.canvas = self.ax.figure.canvas
+
+        # By making this a child of the canvas we make sure that it is
+        # destroyed first and avoids a possible exception when the user clicks
+        # on the window's close box.
+        QtCore.QObject.__init__(self, self.canvas)
+        
         self.cnt = 0
 
         # create the initial line
         self.x = npy.arange(0,2*npy.pi,0.01)
         self.line, = p.plot(self.x, npy.sin(self.x), animated=True, lw=2)
 
         self.background = None
+        self.old_size = 0, 0
 
     def timerEvent(self, evt):
-        if self.background is None:
+        # See if the size has changed since last time round.
+        current_size = self.ax.bbox.width(), self.ax.bbox.height()
+
+        if self.old_size != current_size:
+            self.old_size = current_size
             self.background = self.canvas.copy_from_bbox(self.ax.bbox)
 
         # restore the clean slate background
diff --git a/lib/matplotlib/backends/backend_qt4agg.py b/lib/matplotlib/backends/backend_qt4agg.py
@@ -6,8 +6,6 @@
 import os, sys
 
 import matplotlib
-from matplotlib import verbose
-from matplotlib.cbook import enumerate
 from matplotlib.figure import Figure
 
 from backend_agg import FigureCanvasAgg
@@ -61,7 +59,7 @@ def __init__( self, figure ):
         self.drawRect = False
         self.rect = []
         self.replot = True
-        self.pixmap = QtGui.QPixmap()
+        self.setAttribute(QtCore.Qt.WA_OpaquePaintEvent)
 
     def resizeEvent( self, e ):
         FigureCanvasQT.resizeEvent( self, e )
@@ -86,26 +84,25 @@ def paintEvent( self, e ):
 
         # only replot data when needed
         if type(self.replot) is bool: # might be a bbox for blitting
-            if ( self.replot ):
-                #stringBuffer = str( self.buffer_rgba(0,0) )
-                FigureCanvasAgg.draw( self )
-
-                # matplotlib is in rgba byte order.
-                # qImage wants to put the bytes into argb format and
-                # is in a 4 byte unsigned int.  little endian system is LSB first
-                # and expects the bytes in reverse order (bgra).
-                if ( QtCore.QSysInfo.ByteOrder == QtCore.QSysInfo.LittleEndian ):
-                    stringBuffer = self.renderer._renderer.tostring_bgra()
-                else:
-                    stringBuffer = self.renderer._renderer.tostring_argb()
-                qImage = QtGui.QImage( stringBuffer, self.renderer.width,
-                                       self.renderer.height,
-                                       QtGui.QImage.Format_ARGB32)
-                self.pixmap = self.pixmap.fromImage( qImage )
-            p.drawPixmap( QtCore.QPoint( 0, 0 ), self.pixmap )
+            if self.replot:
+                FigureCanvasAgg.draw(self)
+
+            # matplotlib is in rgba byte order.  QImage wants to put the bytes
+            # into argb format and is in a 4 byte unsigned int.  Little endian
+            # system is LSB first and expects the bytes in reverse order
+            # (bgra).
+            if QtCore.QSysInfo.ByteOrder == QtCore.QSysInfo.LittleEndian:
+                stringBuffer = self.renderer._renderer.tostring_bgra()
+            else:
+                stringBuffer = self.renderer._renderer.tostring_argb()
+
+            qImage = QtGui.QImage(stringBuffer, self.renderer.width,
+                                  self.renderer.height,
+                                  QtGui.QImage.Format_ARGB32)
+            p.drawPixmap(QtCore.QPoint(0, 0), QtGui.QPixmap.fromImage(qImage))
 
             # draw the zoom rectangle to the QPainter
-            if ( self.drawRect ):
+            if self.drawRect:
                 p.setPen( QtGui.QPen( QtCore.Qt.black, 1, QtCore.Qt.DotLine ) )
                 p.drawRect( self.rect[0], self.rect[1], self.rect[2], self.rect[3] )
 
@@ -117,8 +114,8 @@ def paintEvent( self, e ):
             reg = self.copy_from_bbox(bbox)
             stringBuffer = reg.to_string()
             qImage = QtGui.QImage(stringBuffer, w, h, QtGui.QImage.Format_ARGB32)
-            self.pixmap = self.pixmap.fromImage( qImage )
-            p.drawPixmap(QtCore.QPoint(l, self.renderer.height-t), self.pixmap)
+            pixmap = QtGui.QPixmap.fromImage(qImage)
+            p.drawPixmap(QtCore.QPoint(l, self.renderer.height-t), pixmap)
 
         p.end()
         self.replot = False
