Add a context manager for override cursors

[ChangeLog][PySide] A context manager for override cursors
has been added. It is now possible to write code like:
with QApplication.setOverrideCursor(Qt.WaitCursor):...

Change-Id: I443ce82389b48656f21c98df17d97e1b3b3323b5
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

3 files changed, 26 insertions, 31 deletions

diff --git a/examples/widgets/mainwindows/application/application.py b/examples/widgets/mainwindows/application/application.py
index 3ec9344cb..b22f2b7cb 100644
--- a/examples/widgets/mainwindows/application/application.py
+++ b/examples/widgets/mainwindows/application/application.py
@@ -232,27 +232,25 @@ class MainWindow(QMainWindow):
             return
 
         inf = QTextStream(file)
-        QApplication.setOverrideCursor(Qt.WaitCursor)
-        self._text_edit.setPlainText(inf.readAll())
-        QApplication.restoreOverrideCursor()
+        with QApplication.setOverrideCursor(Qt.WaitCursor):
+            self._text_edit.setPlainText(inf.readAll())
 
         self.set_current_file(fileName)
         self.statusBar().showMessage("File loaded", 2000)
 
     def save_file(self, fileName):
         error = None
-        QApplication.setOverrideCursor(Qt.WaitCursor)
-        file = QSaveFile(fileName)
-        if file.open(QFile.WriteOnly | QFile.Text):
-            outf = QTextStream(file)
-            outf << self._text_edit.toPlainText()
-            if not file.commit():
+        with QApplication.setOverrideCursor(Qt.WaitCursor):
+            file = QSaveFile(fileName)
+            if file.open(QFile.WriteOnly | QFile.Text):
+                outf = QTextStream(file)
+                outf << self._text_edit.toPlainText()
+                if not file.commit():
+                    reason = file.errorString()
+                    error = f"Cannot write file {fileName}:\n{reason}."
+            else:
                 reason = file.errorString()
-                error = f"Cannot write file {fileName}:\n{reason}."
-        else:
-            reason = file.errorString()
-            error = f"Cannot open file {fileName}:\n{reason}."
-        QApplication.restoreOverrideCursor()
+                error = f"Cannot open file {fileName}:\n{reason}."
 
         if error:
             QMessageBox.warning(self, "Application", error)
diff --git a/examples/widgets/mainwindows/dockwidgets/dockwidgets.py b/examples/widgets/mainwindows/dockwidgets/dockwidgets.py
index 61b1dd781..db08895d6 100644
--- a/examples/widgets/mainwindows/dockwidgets/dockwidgets.py
+++ b/examples/widgets/mainwindows/dockwidgets/dockwidgets.py
@@ -145,9 +145,8 @@ class MainWindow(QMainWindow):
             return
 
         out = QTextStream(file)
-        QApplication.setOverrideCursor(Qt.WaitCursor)
-        out << self._text_edit.toHtml()
-        QApplication.restoreOverrideCursor()
+        with QApplication.setOverrideCursor(Qt.WaitCursor):
+            out << self._text_edit.toHtml()
 
         self.statusBar().showMessage(f"Saved '{filename}'", 2000)
 
diff --git a/examples/widgets/mainwindows/mdi/mdi.py b/examples/widgets/mainwindows/mdi/mdi.py
index a6ea6284d..06d80b1a1 100644
--- a/examples/widgets/mainwindows/mdi/mdi.py
+++ b/examples/widgets/mainwindows/mdi/mdi.py
@@ -81,9 +81,8 @@ class MdiChild(QTextEdit):
             return False
 
         instr = QTextStream(file)
-        QApplication.setOverrideCursor(Qt.WaitCursor)
-        self.setPlainText(instr.readAll())
-        QApplication.restoreOverrideCursor()
+        with QApplication.setOverrideCursor(Qt.WaitCursor):
+            self.setPlainText(instr.readAll())
 
         self.set_current_file(fileName)
 
@@ -106,18 +105,17 @@ class MdiChild(QTextEdit):
 
     def save_file(self, fileName):
         error = None
-        QApplication.setOverrideCursor(Qt.WaitCursor)
-        file = QSaveFile(fileName)
-        if file.open(QFile.WriteOnly | QFile.Text):
-            outstr = QTextStream(file)
-            outstr << self.toPlainText()
-            if not file.commit():
+        with QApplication.setOverrideCursor(Qt.WaitCursor):
+            file = QSaveFile(fileName)
+            if file.open(QFile.WriteOnly | QFile.Text):
+                outstr = QTextStream(file)
+                outstr << self.toPlainText()
+                if not file.commit():
+                    reason = file.errorString()
+                    error = f"Cannot write file {fileName}:\n{reason}."
+            else:
                 reason = file.errorString()
-                error = f"Cannot write file {fileName}:\n{reason}."
-        else:
-            reason = file.errorString()
-            error = f"Cannot open file {fileName}:\n{reason}."
-        QApplication.restoreOverrideCursor()
+                error = f"Cannot open file {fileName}:\n{reason}."
 
         if error:
             QMessageBox.warning(self, "MDI", error)