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 <tismer@stackless.com>

1 files changed, 18 insertions, 21 deletions

diff --git a/examples/widgets/codeeditor/codeeditor.py b/examples/widgets/codeeditor/codeeditor.py
index bfe92c4a8..47dc8b0a3 100644
--- a/examples/widgets/codeeditor/codeeditor.py
+++ b/examples/widgets/codeeditor/codeeditor.py
@@ -85,29 +85,26 @@ class CodeEditor(QPlainTextEdit):
         self.line_number_area.setGeometry(rect)
 
     def lineNumberAreaPaintEvent(self, event):
-        painter = QPainter(self.line_number_area)
-        painter.fillRect(event.rect(), Qt.lightGray)
-        block = self.firstVisibleBlock()
-        block_number = block.blockNumber()
-        offset = self.contentOffset()
-        top = self.blockBoundingGeometry(block).translated(offset).top()
-        bottom = top + self.blockBoundingRect(block).height()
-
-        while block.isValid() and top <= event.rect().bottom():
-            if block.isVisible() and bottom >= event.rect().top():
-                number = str(block_number + 1)
-                painter.setPen(Qt.black)
-                width = self.line_number_area.width()
-                height = self.fontMetrics().height()
-                painter.drawText(0, top, width, height, Qt.AlignRight, number)
-
-            block = block.next()
-            top = bottom
+        with QPainter(self.line_number_area) as painter:
+            painter.fillRect(event.rect(), Qt.lightGray)
+            block = self.firstVisibleBlock()
+            block_number = block.blockNumber()
+            offset = self.contentOffset()
+            top = self.blockBoundingGeometry(block).translated(offset).top()
             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()
+            while block.isValid() and top <= event.rect().bottom():
+                if block.isVisible() and bottom >= event.rect().top():
+                    number = str(block_number + 1)
+                    painter.setPen(Qt.black)
+                    width = self.line_number_area.width()
+                    height = self.fontMetrics().height()
+                    painter.drawText(0, top, width, height, Qt.AlignRight, number)
+
+                block = block.next()
+                top = bottom
+                bottom = top + self.blockBoundingRect(block).height()
+                block_number += 1
 
     @Slot()
     def update_line_number_area_width(self, newBlockCount):