Let cairo track surface size; fix Pyside refcnt bug.

anntzer · anntzer · commit bcb08e93a7a8 · 2018-01-08T22:27:55.000-08:00
diff --git a/lib/matplotlib/backends/backend_cairo.py b/lib/matplotlib/backends/backend_cairo.py
@@ -102,14 +102,11 @@ def __init__(self, dpi):
 
     def set_ctx_from_surface(self, surface):
         self.gc.ctx = cairo.Context(surface)
+        self.set_width_height(surface.get_width(), surface.get_height())
 
     def set_width_height(self, width, height):
         self.width  = width
         self.height = height
-        self.matrix_flipy = cairo.Matrix(yy=-1, y0=self.height)
-        # use matrix_flipy for ALL rendering?
-        # - problem with text? - will need to switch matrix_flipy off, or do a
-        # font transform?
 
     def _fill_and_stroke(self, ctx, fill_c, alpha, alpha_overrides):
         if fill_c is not None:
@@ -303,11 +300,6 @@ def _draw_mathtext(self, gc, x, y, s, prop, angle):
 
         ctx.restore()
 
-    def flipy(self):
-        return True
-        #return False # tried - all draw objects ok except text (and images?)
-        # which comes out mirrored!
-
     def get_canvas_width_height(self):
         return self.width, self.height
 
@@ -503,7 +495,6 @@ def _save(self, fo, fmt, **kwargs):
 
         # surface.set_dpi() can be used
         renderer = RendererCairo(self.figure.dpi)
-        renderer.set_width_height(width_in_points, height_in_points)
         renderer.set_ctx_from_surface(surface)
         ctx = renderer.gc.ctx
 
diff --git a/lib/matplotlib/backends/backend_qt5agg.py b/lib/matplotlib/backends/backend_qt5agg.py
@@ -78,15 +78,15 @@ def paintEvent(self, e):
             reg = self.copy_from_bbox(bbox)
             buf = reg.to_string_argb()
             qimage = QtGui.QImage(buf, w, h, QtGui.QImage.Format_ARGB32)
+            # Adjust the buf reference count to work around a memory leak bug
+            # in QImage under PySide on Python 3.
+            if QT_API == 'PySide' and six.PY3:
+                ctypes.c_long.from_address(id(buf)).value = 1
             if hasattr(qimage, 'setDevicePixelRatio'):
                 # Not available on Qt4 or some older Qt5.
                 qimage.setDevicePixelRatio(self._dpi_ratio)
             origin = QtCore.QPoint(l, self.renderer.height - t)
             painter.drawImage(origin / self._dpi_ratio, qimage)
-            # Adjust the buf reference count to work around a memory
-            # leak bug in QImage under PySide on Python 3.
-            if QT_API == 'PySide' and six.PY3:
-                ctypes.c_long.from_address(id(buf)).value = 1
 
         self._draw_rect_callback(painter)
 
diff --git a/lib/matplotlib/backends/backend_qt5cairo.py b/lib/matplotlib/backends/backend_qt5cairo.py
@@ -1,5 +1,6 @@
 from . import backend_cairo  # Keep the RendererCairo class swappable.
 from .backend_qt5 import QtCore, QtGui, _BackendQT5, FigureCanvasQT
+from .qt_compat import QT_API
 
 
 class FigureCanvasQTCairo(FigureCanvasQT):
@@ -13,11 +14,14 @@ def paintEvent(self, event):
         surface = backend_cairo.cairo.ImageSurface(
             backend_cairo.cairo.FORMAT_ARGB32, width, height)
         self._renderer.set_ctx_from_surface(surface)
-        # This should be really done by set_ctx_from_surface...
-        self._renderer.set_width_height(width, height)
         self.figure.draw(self._renderer)
-        qimage = QtGui.QImage(surface.get_data(), width, height,
+        buf = surface.get_data()
+        qimage = QtGui.QImage(buf, width, height,
                               QtGui.QImage.Format_ARGB32_Premultiplied)
+        # Adjust the buf reference count to work around a memory leak bug in
+        # QImage under PySide on Python 3.
+        if QT_API == 'PySide' and six.PY3:
+            ctypes.c_long.from_address(id(buf)).value = 1
         painter = QtGui.QPainter(self)
         painter.drawImage(0, 0, qimage)
         self._draw_rect_callback(painter)
