examples: Turn most QPainter instances into context managers

After the new context manager is in place, most of
the examples benefit from moving QPainter into a
`with` statement.

The comments concerning PyPy could be removed, again.

[ChangeLog][PySide6] The examples are updated to use the new
context manager for QPainter.

Task-number: PYSIDE-535
Change-Id: Idf7e1f734d549ed663383ffbb2416297ebb1e0c7
Reviewed-by: Christian Tismer <[email protected]>

7 files changed, 50 insertions, 70 deletions

diff --git a/examples/widgets/tutorials/cannon/t10.py b/examples/widgets/tutorials/cannon/t10.py
index 98b5f57fe..0e553f8c5 100644
--- a/examples/widgets/tutorials/cannon/t10.py
+++ b/examples/widgets/tutorials/cannon/t10.py
@@ -129,17 +129,14 @@ class CannonField(QWidget):
         self.force_changed.emit(self._current_force)
 
     def paintEvent(self, event):
-        painter = QPainter(self)
-
-        painter.setPen(Qt.NoPen)
-        painter.setBrush(Qt.blue)
-
-        painter.translate(0, self.height())
-        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()
+        with QPainter(self) as painter:
+            painter.setPen(Qt.NoPen)
+            painter.setBrush(Qt.blue)
+
+            painter.translate(0, self.height())
+            painter.drawPie(QRect(-35, -35, 70, 70), 0, 90 * 16)
+            painter.rotate(-self._current_angle)
+            painter.drawRect(QRect(33, -4, 15, 8))
 
     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 ea8e53a8e..fa2198e10 100644
--- a/examples/widgets/tutorials/cannon/t11.py
+++ b/examples/widgets/tutorials/cannon/t11.py
@@ -159,13 +159,10 @@ class CannonField(QWidget):
         self.update(region)
 
     def paintEvent(self, event):
-        painter = QPainter(self)
-
-        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()
+        with QPainter(self) as painter:
+            self.paint_cannon(painter)
+            if self._auto_shoot_timer.isActive():
+                self.paint_shot(painter)
 
     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 98b2ff248..bfde8d5de 100644
--- a/examples/widgets/tutorials/cannon/t12.py
+++ b/examples/widgets/tutorials/cannon/t12.py
@@ -198,15 +198,12 @@ class CannonField(QWidget):
         self.update(region)
 
     def paintEvent(self, event):
-        painter = QPainter(self)
+        with QPainter(self) as painter:
+            self.paint_cannon(painter)
+            if self._auto_shoot_timer.isActive():
+                self.paint_shot(painter)
 
-        self.paint_cannon(painter)
-        if self._auto_shoot_timer.isActive():
-            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()
+            self.paint_target(painter)
 
     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 3ac05f435..fe487de53 100644
--- a/examples/widgets/tutorials/cannon/t13.py
+++ b/examples/widgets/tutorials/cannon/t13.py
@@ -220,20 +220,17 @@ class CannonField(QWidget):
         self.update(region)
 
     def paintEvent(self, event):
-        painter = QPainter(self)
-
-        if self._game_ended:
-            painter.setPen(Qt.black)
-            painter.setFont(QFont("Courier", 48, QFont.Bold))
-            painter.drawText(self.rect(), Qt.AlignCenter, "Game Over")
-
-        self.paint_cannon(painter)
-        if self.is_shooting():
-            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()
+        with QPainter(self) as painter:
+            if self._game_ended:
+                painter.setPen(Qt.black)
+                painter.setFont(QFont("Courier", 48, QFont.Bold))
+                painter.drawText(self.rect(), Qt.AlignCenter, "Game Over")
+
+            self.paint_cannon(painter)
+            if self.is_shooting():
+                self.paint_shot(painter)
+            if not self._game_ended:
+                self.paint_target(painter)
 
     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 8a3fe98e8..ac6924a3b 100644
--- a/examples/widgets/tutorials/cannon/t14.py
+++ b/examples/widgets/tutorials/cannon/t14.py
@@ -243,21 +243,18 @@ class CannonField(QWidget):
             self._barrel_pressed = False
 
     def paintEvent(self, event):
-        painter = QPainter(self)
-
-        if self._game_ended:
-            painter.setPen(Qt.black)
-            painter.setFont(QFont("Courier", 48, QFont.Bold))
-            painter.drawText(self.rect(), Qt.AlignCenter, "Game Over")
-
-        self.paint_cannon(painter)
-        self.paint_barrier(painter)
-        if self.is_shooting():
-            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()
+        with QPainter(self) as painter:
+            if self._game_ended:
+                painter.setPen(Qt.black)
+                painter.setFont(QFont("Courier", 48, QFont.Bold))
+                painter.drawText(self.rect(), Qt.AlignCenter, "Game Over")
+
+            self.paint_cannon(painter)
+            self.paint_barrier(painter)
+            if self.is_shooting():
+                self.paint_shot(painter)
+            if not self._game_ended:
+                self.paint_target(painter)
 
     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 b02a049cc..757015495 100644
--- a/examples/widgets/tutorials/cannon/t8.py
+++ b/examples/widgets/tutorials/cannon/t8.py
@@ -115,10 +115,8 @@ class CannonField(QWidget):
         self.angle_changed.emit(self._current_angle)
 
     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()
+        with QPainter(self) as painter:
+            painter.drawText(200, 200, f"Angle = {self._current_angle}")
 
 
 class MyWidget(QWidget):
diff --git a/examples/widgets/tutorials/cannon/t9.py b/examples/widgets/tutorials/cannon/t9.py
index f18144310..a682c8356 100644
--- a/examples/widgets/tutorials/cannon/t9.py
+++ b/examples/widgets/tutorials/cannon/t9.py
@@ -115,17 +115,14 @@ class CannonField(QWidget):
         self.angle_changed.emit(self._current_angle)
 
     def paintEvent(self, event):
-        painter = QPainter(self)
-
-        painter.setPen(Qt.NoPen)
-        painter.setBrush(Qt.blue)
-
-        painter.translate(0, self.rect().height())
-        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()
+        with QPainter(self) as painter:
+            painter.setPen(Qt.NoPen)
+            painter.setBrush(Qt.blue)
+
+            painter.translate(0, self.rect().height())
+            painter.drawPie(QRect(-35, -35, 70, 70), 0, 90 * 16)
+            painter.rotate(-self._current_angle)
+            painter.drawRect(QRect(33, -4, 15, 8))
 
 
 class MyWidget(QWidget):