split backend_qt4agg into two parts.

One part (_backend_qt4Agg.py) has no dependencies on Gcf or pyplot, which are all collected in backend_qt4agg.py. Should be fully back-wards compatible.
matplotlib · tacaswell · Nov 29, 2013 · Nov 29, 2013 · Nov 29, 2013 · Nov 29, 2013
commit 3014931eaf65dfd24543fa5d91bc1e1d8a2d8c9f
diff --git a/lib/matplotlib/backends/_backend_qt4agg.py b/lib/matplotlib/backends/_backend_qt4agg.py
@@ -0,0 +1,164 @@
+"""
+Render to qt from agg
+"""
+from __future__ import (absolute_import, division, print_function,
+                        unicode_literals)
+
+import six
+
+import sys
+import ctypes
+
+import matplotlib
+from matplotlib.figure import Figure
+# grab Agg canvas
+from .backend_agg import FigureCanvasAgg
+# grab the qt4 compat stuff directly
+from .qt4_compat import QtCore, QtGui
+
+# grab the Gcf-less qt4 classes
+from ._backend_qt4 import FigureManagerQT
+from ._backend_qt4 import FigureCanvasQT
+from ._backend_qt4 import NavigationToolbar2QT
+
+DEBUG = False
+
+_decref = ctypes.pythonapi.Py_DecRef
+_decref.argtypes = [ctypes.py_object]
+_decref.restype = None
+
+
+def new_figure_manager(num, *args, **kwargs):
+    """
+    Create a new figure manager instance
+    """
+    if DEBUG:
+        print('backend_qtagg.new_figure_manager')
+    FigureClass = kwargs.pop('FigureClass', Figure)
+    thisFig = FigureClass(*args, **kwargs)
+    return new_figure_manager_given_figure(num, thisFig)
+
+
+def new_figure_manager_given_figure(num, figure):
+    """
+    Create a new figure manager instance for the given figure.
+    """
+    canvas = FigureCanvasQTAgg(figure)
+    return FigureManagerQT(canvas, num)
+
+
+class FigureCanvasQTAgg(FigureCanvasQT, FigureCanvasAgg):
+    """
+    The canvas the figure renders into.  Calls the draw and print fig
+    methods, creates the renderers, etc...
+
+    Public attribute
+
+      figure - A Figure instance
+   """
+
+    def __init__(self, figure):
+        if DEBUG:
+            print('FigureCanvasQtAgg: ', figure)
+        FigureCanvasQT.__init__(self, figure)
+        FigureCanvasAgg.__init__(self, figure)
+        self.drawRect = False
+        self.rect = []
+        self.blitbox = None
+        self.setAttribute(QtCore.Qt.WA_OpaquePaintEvent)
+
+    def drawRectangle(self, rect):
+        self.rect = rect
+        self.drawRect = True
+        self.repaint()
+
+    def paintEvent(self, e):
+        """
+        Copy the image from the Agg canvas to the qt.drawable.
+        In Qt, all drawing should be done inside of here when a widget is
+        shown onscreen.
+        """
+
+        #FigureCanvasQT.paintEvent(self, e)
+        if DEBUG:
+            print('FigureCanvasQtAgg.paintEvent: ', self,
+                self.get_width_height())
+
+        if self.blitbox is None:
+            # 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()
+
+            refcnt = sys.getrefcount(stringBuffer)
+
+            # convert the Agg rendered image -> qImage
+            qImage = QtGui.QImage(stringBuffer, self.renderer.width,
+                                  self.renderer.height,
+                                  QtGui.QImage.Format_ARGB32)
+            # get the rectangle for the image
+            rect = qImage.rect()
+            p = QtGui.QPainter(self)
+            # reset the image area of the canvas to be the back-ground color
+            p.eraseRect(rect)
+            # draw the rendered image on to the canvas
+            p.drawPixmap(QtCore.QPoint(0, 0), QtGui.QPixmap.fromImage(qImage))
+
+            # draw the zoom rectangle to the QPainter
+            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])
+            p.end()
+
+            # This works around a bug in PySide 1.1.2 on Python 3.x,
+            # where the reference count of stringBuffer is incremented
+            # but never decremented by QImage.
+            # TODO: revert PR #1323 once the issue is fixed in PySide.
+            del qImage
+            if refcnt != sys.getrefcount(stringBuffer):
+                _decref(stringBuffer)
+        else:
+            bbox = self.blitbox
+            l, b, r, t = bbox.extents
+            w = int(r) - int(l)
+            h = int(t) - int(b)
+            t = int(b) + h
+            reg = self.copy_from_bbox(bbox)
+            stringBuffer = reg.to_string_argb()
+            qImage = QtGui.QImage(stringBuffer, w, h,
+                                  QtGui.QImage.Format_ARGB32)
+            pixmap = QtGui.QPixmap.fromImage(qImage)
+            p = QtGui.QPainter(self)
+            p.drawPixmap(QtCore.QPoint(l, self.renderer.height-t), pixmap)
+            p.end()
+            self.blitbox = None
+        self.drawRect = False
+
+    def draw(self):
+        """
+        Draw the figure with Agg, and queue a request
+        for a Qt draw.
+        """
+        # The Agg draw is done here; delaying it until the paintEvent
+        # causes problems with code that uses the result of the
+        # draw() to update plot elements.
+        FigureCanvasAgg.draw(self)
+        self.update()
+
+    def blit(self, bbox=None):
+        """
+        Blit the region in bbox
+        """
+        self.blitbox = bbox
+        l, b, w, h = bbox.bounds
+        t = b + h
+        self.repaint(l, self.renderer.height-t, w, h)
+
+    def print_figure(self, *args, **kwargs):
+        FigureCanvasAgg.print_figure(self, *args, **kwargs)
+        self.draw()
diff --git a/lib/matplotlib/backends/backend_qt4agg.py b/lib/matplotlib/backends/backend_qt4agg.py
@@ -5,169 +5,31 @@
                         unicode_literals)
 
 import six
-
-import os  # not used
-import sys
-import ctypes
 import warnings
-
-import matplotlib
-from matplotlib.figure import Figure
-
-from .backend_agg import FigureCanvasAgg
-from .backend_qt4 import QtCore
-from .backend_qt4 import QtGui
-from .backend_qt4 import FigureManagerQT
-from .backend_qt4 import FigureCanvasQT
-from .backend_qt4 import NavigationToolbar2QT
-##### not used
-from .backend_qt4 import show
-from .backend_qt4 import draw_if_interactive
-from .backend_qt4 import backend_version
-######
 from matplotlib.cbook import mplDeprecation
 
-DEBUG = False
-
-_decref = ctypes.pythonapi.Py_DecRef
-_decref.argtypes = [ctypes.py_object]
-_decref.restype = None
-
-
-def new_figure_manager(num, *args, **kwargs):
-    """
-    Create a new figure manager instance
-    """
-    if DEBUG:
-        print('backend_qtagg.new_figure_manager')
-    FigureClass = kwargs.pop('FigureClass', Figure)
-    thisFig = FigureClass(*args, **kwargs)
-    return new_figure_manager_given_figure(num, thisFig)
-
-
-def new_figure_manager_given_figure(num, figure):
-    """
-    Create a new figure manager instance for the given figure.
-    """
-    canvas = FigureCanvasQTAgg(figure)
-    return FigureManagerQT(canvas, num)
-
+# import Gcf/pyplot stuff
+from matplotlib._pylab_helpers import Gcf
 
-class FigureCanvasQTAgg(FigureCanvasQT, FigureCanvasAgg):
-    """
-    The canvas the figure renders into.  Calls the draw and print fig
-    methods, creates the renderers, etc...
 
-    Public attribute
-
-      figure - A Figure instance
-   """
-
-    def __init__(self, figure):
-        if DEBUG:
-            print('FigureCanvasQtAgg: ', figure)
-        FigureCanvasQT.__init__(self, figure)
-        FigureCanvasAgg.__init__(self, figure)
-        self.drawRect = False
-        self.rect = []
-        self.blitbox = None
-        self.setAttribute(QtCore.Qt.WA_OpaquePaintEvent)
-
-    def drawRectangle(self, rect):
-        self.rect = rect
-        self.drawRect = True
-        self.repaint()
-
-    def paintEvent(self, e):
-        """
-        Copy the image from the Agg canvas to the qt.drawable.
-        In Qt, all drawing should be done inside of here when a widget is
-        shown onscreen.
-        """
-
-        #FigureCanvasQT.paintEvent(self, e)
-        if DEBUG:
-            print('FigureCanvasQtAgg.paintEvent: ', self,
-                self.get_width_height())
-
-        if self.blitbox is None:
-            # 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()
-
-            refcnt = sys.getrefcount(stringBuffer)
-
-            # convert the Agg rendered image -> qImage
-            qImage = QtGui.QImage(stringBuffer, self.renderer.width,
-                                  self.renderer.height,
-                                  QtGui.QImage.Format_ARGB32)
-            # get the rectangle for the image
-            rect = qImage.rect()
-            p = QtGui.QPainter(self)
-            # reset the image area of the canvas to be the back-ground color
-            p.eraseRect(rect)
-            # draw the rendered image on to the canvas
-            p.drawPixmap(QtCore.QPoint(0, 0), QtGui.QPixmap.fromImage(qImage))
+# import Gcf stuff from QT4 backend
+from .backend_qt4 import show
+from .backend_qt4 import draw_if_interactive
 
-            # draw the zoom rectangle to the QPainter
-            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])
-            p.end()
+# import the backend with call backs included from
+from .backend_qt4 import FigureManagerQT
 
-            # This works around a bug in PySide 1.1.2 on Python 3.x,
-            # where the reference count of stringBuffer is incremented
-            # but never decremented by QImage.
-            # TODO: revert PR #1323 once the issue is fixed in PySide.
-            del qImage
-            if refcnt != sys.getrefcount(stringBuffer):
-                _decref(stringBuffer)
-        else:
-            bbox = self.blitbox
-            l, b, r, t = bbox.extents
-            w = int(r) - int(l)
-            h = int(t) - int(b)
-            t = int(b) + h
-            reg = self.copy_from_bbox(bbox)
-            stringBuffer = reg.to_string_argb()
-            qImage = QtGui.QImage(stringBuffer, w, h,
-                                  QtGui.QImage.Format_ARGB32)
-            pixmap = QtGui.QPixmap.fromImage(qImage)
-            p = QtGui.QPainter(self)
-            p.drawPixmap(QtCore.QPoint(l, self.renderer.height-t), pixmap)
-            p.end()
-            self.blitbox = None
-        self.drawRect = False
 
-    def draw(self):
-        """
-        Draw the figure with Agg, and queue a request
-        for a Qt draw.
-        """
-        # The Agg draw is done here; delaying it until the paintEvent
-        # causes problems with code that uses the result of the
-        # draw() to update plot elements.
-        FigureCanvasAgg.draw(self)
-        self.update()
+from ._backend_qt4 import (TimerQT,
+                            SubplotToolQt,
+                            backend_version)
 
-    def blit(self, bbox=None):
-        """
-        Blit the region in bbox
-        """
-        self.blitbox = bbox
-        l, b, w, h = bbox.bounds
-        t = b + h
-        self.repaint(l, self.renderer.height-t, w, h)
 
-    def print_figure(self, *args, **kwargs):
-        FigureCanvasAgg.print_figure(self, *args, **kwargs)
-        self.draw()
+# import qtAgg stuff
+from ._backend_qt4agg import (new_figure_manager,
+                              new_figure_manager_given_figure,
+                              NavigationToolbar2QT,
+                              FigureCanvasQTAgg)
 
 
 class NavigationToolbar2QTAgg(NavigationToolbar2QT):