Merge pull request #36722 from rouault/fix_30210

QgsBinaryWidgetWrapper: fix focus-related crash
qgis · May 26, 2020 · bcea438 · bcea438
2 parents 63c34e3 + 46c9d1f
commit bcea438
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Showing 4 changed files with 116 additions and 10 deletions.
diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
@@ -416,6 +416,7 @@ SET(QGIS_GUI_SRCS
   qgsfilterlineedit.cpp
   qgsfindfilesbypatternwidget.cpp
   qgsfloatingwidget.cpp
+  qgsfocuskeeper.cpp
   qgsfocuswatcher.cpp
   qgsfontbutton.cpp
   qgsformannotation.cpp

diff --git a/src/gui/editorwidgets/qgsbinarywidgetwrapper.cpp b/src/gui/editorwidgets/qgsbinarywidgetwrapper.cpp
@@ -17,6 +17,7 @@
 #include "qgsvectorlayer.h"
 #include "qgsvectordataprovider.h"
 #include "qgsfileutils.h"
+#include "qgsfocuskeeper.h"
 #include "qgssettings.h"
 #include "qgsmessagebar.h"
 #include "qgsapplication.h"
@@ -135,10 +136,16 @@ void QgsBinaryWidgetWrapper::updateValues( const QVariant &value, const QVariant
 void QgsBinaryWidgetWrapper::saveContent()
 {
   QgsSettings s;
-  QString file = QFileDialog::getSaveFileName( nullptr,
-                 tr( "Save Contents to File" ),
-                 defaultPath(),
-                 tr( "All files" ) + " (*.*)" );
+
+  QString file;
+  {
+    QgsFocusKeeper focusKeeper;
+
+    file = QFileDialog::getSaveFileName( nullptr,
+                                         tr( "Save Contents to File" ),
+                                         defaultPath(),
+                                         tr( "All files" ) + " (*.*)" );
+  }
   if ( file.isEmpty() )
   {
     return;
@@ -160,10 +167,17 @@ void QgsBinaryWidgetWrapper::saveContent()
 void QgsBinaryWidgetWrapper::setContent()
 {
   QgsSettings s;
-  QString file = QFileDialog::getOpenFileName( nullptr,
-                 tr( "Embed File" ),
-                 defaultPath(),
-                 tr( "All files" ) + " (*.*)" );
+
+  QString file;
+  {
+    QgsFocusKeeper focusKeeper;
+
+    file = QFileDialog::getOpenFileName( nullptr,
+                                         tr( "Embed File" ),
+                                         defaultPath(),
+                                         tr( "All files" ) + " (*.*)" );
+  }
+
   QFileInfo fi( file );
   if ( file.isEmpty() || !fi.exists() )
   {
@@ -184,8 +198,11 @@ void QgsBinaryWidgetWrapper::setContent()
 
 void QgsBinaryWidgetWrapper::clear()
 {
-  if ( QMessageBox::question( nullptr, tr( "Clear Contents" ), tr( "Are you sure you want the clear this field's content?" ), QMessageBox::Yes | QMessageBox::No, QMessageBox::No ) != QMessageBox::Yes )
-    return;
+  {
+    QgsFocusKeeper focusKeeper;
+    if ( QMessageBox::question( nullptr, tr( "Clear Contents" ), tr( "Are you sure you want the clear this field's content?" ), QMessageBox::Yes | QMessageBox::No, QMessageBox::No ) != QMessageBox::Yes )
+      return;
+  }
 
   updateValues( QByteArray() );
   emitValueChanged();

diff --git a/src/gui/qgsfocuskeeper.cpp b/src/gui/qgsfocuskeeper.cpp
@@ -0,0 +1,40 @@
+/***************************************************************************
+    qgsfocuskeeper.cpp
+     -----------------
+    Date                 : May 2020
+    Copyright            : (C) 2020 Even Rouault
+    Email                : even dot rouault at spatialys dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsfocuskeeper.h"
+
+#include <QApplication>
+#include <QEvent>
+#include <QWidget>
+
+QgsFocusKeeper::QgsFocusKeeper(): mWidgetToKeepFocused( QApplication::focusWidget() )
+{
+  mWidgetToKeepFocused->installEventFilter( this );
+}
+
+QgsFocusKeeper::~QgsFocusKeeper()
+{
+  mWidgetToKeepFocused->removeEventFilter( this );
+}
+
+bool QgsFocusKeeper::eventFilter( QObject *obj, QEvent *event )
+{
+  if ( obj == mWidgetToKeepFocused && event &&
+       ( event->type() == QEvent::FocusOut ||  event->type() == QEvent::FocusAboutToChange ) )
+  {
+    return true;
+  }
+  return QObject::eventFilter( obj, event );
+}
diff --git a/src/gui/qgsfocuskeeper.h b/src/gui/qgsfocuskeeper.h
@@ -0,0 +1,48 @@
+/***************************************************************************
+    qgsfocuskeeper.h
+     ---------------
+    Date                 : May 2020
+    Copyright            : (C) 2020 Even Rouault
+    Email                : even dot rouault at spatialys dot com
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSFOCUSKEEPER_H
+#define QGSFOCUSKEEPER_H
+
+#include "qgis_gui.h"
+
+#define SIP_NO_FILE
+
+#include <QObject>
+
+class QWidget;
+
+/**
+ * \ingroup gui
+ * \class QgsFocusKeeper
+ * Trick to keep a widget focused and avoid QT crashes
+ * \note not available in Python bindings
+ * \since QGIS 3.14
+ */
+class GUI_EXPORT QgsFocusKeeper : public QObject
+{
+    Q_OBJECT
+
+    QWidget *mWidgetToKeepFocused = nullptr;
+
+  public:
+    QgsFocusKeeper();
+    ~QgsFocusKeeper() override;
+
+  protected:
+    bool eventFilter( QObject *obj, QEvent *event ) override;
+};
+
+#endif // QGSFOCUSKEEPER_H