PyPySide: handle QPainter correctly with GC

While testing the examples with PyPy, a number of examples
used QPainter without explicitly calling painter.end() and
crashed.

This works in standard Python, but leaves the painter open
in other implementations, because the implicit deletion of
objects when going out of scope does not work in the
wrapper when garbage collection is used.

Fixed by providing the missing painter.end() calls.

This problem should finally be fixed by making QPainter a
context manager. The same approach was taken by Python.org and
the file open/close functions. The context manager was needed
for implementations like IronPython, Jython and PyPy.

[ChangeLog][PySide6] The examples were adapted to PyPy's
need to close QPainter, explicitly. Eventually, we may turn
this into a context manager.

Change-Id: I18eeeff7df800bafce91a1e5c98c469aa3bcc41b
Pick-to: 6.2
Task-number: PYSIDE-535
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

22 files changed, 53 insertions, 0 deletions

diff --git a/examples/corelib/threads/mandelbrot.py b/examples/corelib/threads/mandelbrot.py
index c95966119..70658dc58 100644
--- a/examples/corelib/threads/mandelbrot.py
+++ b/examples/corelib/threads/mandelbrot.py
@@ -260,6 +260,8 @@ class MandelbrotWidget(QWidget):
             painter.setPen(Qt.white)
             painter.drawText(self.rect(), Qt.AlignCenter,
                     "Rendering initial image, please wait...")
+            # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+            painter.end()
             return
 
         if self._cur_scale == self._pixmap_scale:
@@ -292,6 +294,8 @@ class MandelbrotWidget(QWidget):
         painter.setPen(Qt.white)
         painter.drawText((self.width() - text_width) / 2,
                 metrics.leading() + metrics.ascent(), text)
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     def resizeEvent(self, event):
         self.thread.render(self._center_x, self._center_y, self._cur_scale, self.size())
diff --git a/examples/designer/taskmenuextension/tictactoe.py b/examples/designer/taskmenuextension/tictactoe.py
index ce806426f..c4fe16e10 100644
--- a/examples/designer/taskmenuextension/tictactoe.py
+++ b/examples/designer/taskmenuextension/tictactoe.py
@@ -150,6 +150,9 @@ class TicTacToe(QWidget):
             painter.drawLine(0, self.height(), self.width(), 0)
             self._turn_number = 9
 
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
+
     def _cell_rect(self, position):
         h_margin = self.width() / 30
         v_margin = self.height() / 30
diff --git a/examples/multimedia/audiosource/audiosource.py b/examples/multimedia/audiosource/audiosource.py
index d61aaae7e..8f11e5c4b 100644
--- a/examples/multimedia/audiosource/audiosource.py
+++ b/examples/multimedia/audiosource/audiosource.py
@@ -119,12 +119,16 @@ class RenderArea(QWidget):
         painter.drawRect(frame)
 
         if self.m_level == 0.0:
+            # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+            painter.end()
             return
 
         pos: int = round((frame.width() - 1) * self.m_level)
         painter.fillRect(
             frame.left() + 1, frame.top() + 1, pos, frame.height() - 1, Qt.red
         )
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
 
 class InputTest(QWidget):
diff --git a/examples/quick3d/intro/main.py b/examples/quick3d/intro/main.py
index 050f9d632..c3189fb23 100644
--- a/examples/quick3d/intro/main.py
+++ b/examples/quick3d/intro/main.py
@@ -38,6 +38,7 @@
 ##
 #############################################################################
 
+import os
 import sys
 from pathlib import Path
 from PySide6.QtCore import QUrl
diff --git a/examples/widgetbinding/wigglywidget.py b/examples/widgetbinding/wigglywidget.py
index 482415ae6..11f4a81a5 100644
--- a/examples/widgetbinding/wigglywidget.py
+++ b/examples/widgetbinding/wigglywidget.py
@@ -99,6 +99,9 @@ class WigglyWidget(QWidget):
             painter.drawText(x, y - dy, str(c))
             x += metrics.horizontalAdvance(c)
 
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
+
     def timerEvent(self, event):
         if event.timerId() == self._timer.timerId():
             self._step += 1
diff --git a/examples/widgets/animation/easing/easing.py b/examples/widgets/animation/easing/easing.py
index ba7f2d363..a7bff7842 100644
--- a/examples/widgets/animation/easing/easing.py
+++ b/examples/widgets/animation/easing/easing.py
@@ -218,6 +218,7 @@ class Window(QWidget):
             item.setText(curve_name)
             self._ui.easingCurvePicker.addItem(item)
 
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
         painter.end()
 
     def start_animation(self):
diff --git a/examples/widgets/codeeditor/codeeditor.py b/examples/widgets/codeeditor/codeeditor.py
index f5f119000..bfe92c4a8 100644
--- a/examples/widgets/codeeditor/codeeditor.py
+++ b/examples/widgets/codeeditor/codeeditor.py
@@ -106,6 +106,9 @@ class CodeEditor(QPlainTextEdit):
             bottom = top + self.blockBoundingRect(block).height()
             block_number += 1
 
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
+
     @Slot()
     def update_line_number_area_width(self, newBlockCount):
         self.setViewportMargins(self.line_number_area_width(), 0, 0, 0)
diff --git a/examples/widgets/draganddrop/draggableicons/draggableicons.py b/examples/widgets/draganddrop/draggableicons/draggableicons.py
index f8411de2e..5fe6590e7 100644
--- a/examples/widgets/draganddrop/draggableicons/draggableicons.py
+++ b/examples/widgets/draganddrop/draggableicons/draggableicons.py
@@ -152,6 +152,9 @@ class DragWidget(QFrame):
             child.show()
             child.setPixmap(pixmap)
 
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
+
 
 if __name__ == "__main__":
     app = QApplication(sys.argv)
diff --git a/examples/widgets/graphicsview/diagramscene/diagramscene.py b/examples/widgets/graphicsview/diagramscene/diagramscene.py
index b068a8253..aca95ccb9 100644
--- a/examples/widgets/graphicsview/diagramscene/diagramscene.py
+++ b/examples/widgets/graphicsview/diagramscene/diagramscene.py
@@ -242,6 +242,8 @@ class DiagramItem(QGraphicsPolygonItem):
         painter.setPen(QPen(Qt.black, 8))
         painter.translate(125, 125)
         painter.drawPolyline(self._my_polygon)
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
         return pixmap
 
     def contextMenuEvent(self, event):
diff --git a/examples/widgets/itemviews/stardelegate/stareditor.py b/examples/widgets/itemviews/stardelegate/stareditor.py
index 8431f4a38..9e3a5f4df 100644
--- a/examples/widgets/itemviews/stardelegate/stareditor.py
+++ b/examples/widgets/itemviews/stardelegate/stareditor.py
@@ -72,6 +72,8 @@ class StarEditor(QWidget):
         """ Paint the editor, offloading the work to the StarRating class. """
         painter = QPainter(self)
         self.star_rating.paint(painter, self.rect(), self.palette(), isEditable=True)
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     def mouseMoveEvent(self, event):
         """ As the mouse moves inside the editor, track the position and
diff --git a/examples/widgets/painting/basicdrawing/basicdrawing.py b/examples/widgets/painting/basicdrawing/basicdrawing.py
index d7849b0cc..a0d5bda7c 100644
--- a/examples/widgets/painting/basicdrawing/basicdrawing.py
+++ b/examples/widgets/painting/basicdrawing/basicdrawing.py
@@ -164,6 +164,8 @@ class RenderArea(QWidget):
         painter.setPen(self.palette().dark().color())
         painter.setBrush(Qt.NoBrush)
         painter.drawRect(QRect(0, 0, self.width() - 1, self.height() - 1))
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
 
 id_role = Qt.UserRole
diff --git a/examples/widgets/painting/concentriccircles/concentriccircles.py b/examples/widgets/painting/concentriccircles/concentriccircles.py
index d3df51099..2786396cb 100644
--- a/examples/widgets/painting/concentriccircles/concentriccircles.py
+++ b/examples/widgets/painting/concentriccircles/concentriccircles.py
@@ -95,6 +95,9 @@ class CircleWidget(QWidget):
                     painter.drawEllipse(QRect(-diameter / 2,
                             -diameter / 2, diameter, diameter))
 
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
+
 
 class Window(QWidget):
     def __init__(self):
diff --git a/examples/widgets/state-machine/rogue/rogue.py b/examples/widgets/state-machine/rogue/rogue.py
index c8e4565ba..255785f95 100644
--- a/examples/widgets/state-machine/rogue/rogue.py
+++ b/examples/widgets/state-machine/rogue/rogue.py
@@ -180,6 +180,8 @@ class MainWindow(QMainWindow):
                 painter.drawText(QPoint(x_pos, y_pos), self.map[x][y])
                 x_pos += font_width
         painter.drawText(QPoint(self.pX * font_width, (self.pY + 2) * font_height), '@')
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     def move_player(self, direction):
         if direction == self.left:
diff --git a/examples/widgets/state-machine/trafficlight/trafficlight.py b/examples/widgets/state-machine/trafficlight/trafficlight.py
index 0d7fcd15c..b5e975cfc 100644
--- a/examples/widgets/state-machine/trafficlight/trafficlight.py
+++ b/examples/widgets/state-machine/trafficlight/trafficlight.py
@@ -78,6 +78,8 @@ class LightWidget(QWidget):
         painter.setRenderHint(QPainter.Antialiasing)
         painter.setBrush(self.color)
         painter.drawEllipse(0, 0, self.width(), self.height())
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     on = Property(bool, is_on, set_on)
 
diff --git a/examples/widgets/tetrix/tetrix.py b/examples/widgets/tetrix/tetrix.py
index 3b4d32cca..c70e634b4 100644
--- a/examples/widgets/tetrix/tetrix.py
+++ b/examples/widgets/tetrix/tetrix.py
@@ -236,6 +236,8 @@ class TetrixBoard(QFrame):
                 self.draw_square(painter, rect.left() + x * self.square_width(),
                         board_top + (TetrixBoard.board_height - y - 1) * self.square_height(),
                         self._cur_piece.shape())
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     def keyPressEvent(self, event):
         if not self._is_started or self._is_paused or self._cur_piece.shape() == Piece.NoShape:
@@ -359,6 +361,8 @@ class TetrixBoard(QFrame):
         pixmap = QPixmap(dx * self.square_width(), dy * self.square_height())
         painter = QPainter(pixmap)
         painter.fillRect(pixmap.rect(), self.nextPieceLabel.palette().background())
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
         for int in range(4):
             x = self._next_piece.x(i) - self._next_piece.min_x()
diff --git a/examples/widgets/tutorials/cannon/t10.py b/examples/widgets/tutorials/cannon/t10.py
index ed3d9fce3..98b5f57fe 100644
--- a/examples/widgets/tutorials/cannon/t10.py
+++ b/examples/widgets/tutorials/cannon/t10.py
@@ -138,6 +138,8 @@ class CannonField(QWidget):
         painter.drawPie(QRect(-35, -35, 70, 70), 0, 90 * 16)
         painter.rotate(-self._current_angle)
         painter.drawRect(QRect(33, -4, 15, 8))
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     def cannon_rect(self):
         result = QRect(0, 0, 50, 50)
diff --git a/examples/widgets/tutorials/cannon/t11.py b/examples/widgets/tutorials/cannon/t11.py
index f297a14b4..ea8e53a8e 100644
--- a/examples/widgets/tutorials/cannon/t11.py
+++ b/examples/widgets/tutorials/cannon/t11.py
@@ -164,6 +164,8 @@ class CannonField(QWidget):
         self.paint_cannon(painter)
         if self._auto_shoot_timer.isActive():
             self.paint_shot(painter)
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     def paint_shot(self, painter):
         painter.setPen(Qt.NoPen)
diff --git a/examples/widgets/tutorials/cannon/t12.py b/examples/widgets/tutorials/cannon/t12.py
index f2c6ea08c..98b2ff248 100644
--- a/examples/widgets/tutorials/cannon/t12.py
+++ b/examples/widgets/tutorials/cannon/t12.py
@@ -205,6 +205,8 @@ class CannonField(QWidget):
             self.paint_shot(painter)
 
         self.paint_target(painter)
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     def paint_shot(self, painter):
         painter.setPen(Qt.NoPen)
diff --git a/examples/widgets/tutorials/cannon/t13.py b/examples/widgets/tutorials/cannon/t13.py
index aa00825aa..3ac05f435 100644
--- a/examples/widgets/tutorials/cannon/t13.py
+++ b/examples/widgets/tutorials/cannon/t13.py
@@ -232,6 +232,8 @@ class CannonField(QWidget):
             self.paint_shot(painter)
         if not self._game_ended:
             self.paint_target(painter)
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     def paint_shot(self, painter):
         painter.setPen(Qt.NoPen)
diff --git a/examples/widgets/tutorials/cannon/t14.py b/examples/widgets/tutorials/cannon/t14.py
index 0e8318ebe..8a3fe98e8 100644
--- a/examples/widgets/tutorials/cannon/t14.py
+++ b/examples/widgets/tutorials/cannon/t14.py
@@ -256,6 +256,8 @@ class CannonField(QWidget):
             self.paint_shot(painter)
         if not self._game_ended:
             self.paint_target(painter)
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
     def paint_shot(self, painter):
         painter.setPen(Qt.NoPen)
diff --git a/examples/widgets/tutorials/cannon/t8.py b/examples/widgets/tutorials/cannon/t8.py
index cc54194cf..b02a049cc 100644
--- a/examples/widgets/tutorials/cannon/t8.py
+++ b/examples/widgets/tutorials/cannon/t8.py
@@ -117,6 +117,8 @@ class CannonField(QWidget):
     def paintEvent(self, event):
         painter = QPainter(self)
         painter.drawText(200, 200, f"Angle = {self._current_angle}")
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
 
 class MyWidget(QWidget):
diff --git a/examples/widgets/tutorials/cannon/t9.py b/examples/widgets/tutorials/cannon/t9.py
index 36dcf8fb1..f18144310 100644
--- a/examples/widgets/tutorials/cannon/t9.py
+++ b/examples/widgets/tutorials/cannon/t9.py
@@ -124,6 +124,8 @@ class CannonField(QWidget):
         painter.drawPie(QRect(-35, -35, 70, 70), 0, 90 * 16)
         painter.rotate(-self._current_angle)
         painter.drawRect(QRect(33, -4, 15, 8))
+        # QPainter needs an explicit end() in PyPy. This will become a context manager in 6.3.
+        painter.end()
 
 
 class MyWidget(QWidget):