fix(SvgSelectorWidget): Correctly use QPixmapCache

With previous code, pixmap was never taken from cache

src/gui/symbology/qgssvgselectorwidget.cpp

@@ -288,16 +288,16 @@ QVariant QgsSvgSelectorListModel::data( const QModelIndex &index, int role ) con
 
   if ( role == Qt::DecorationRole ) // icon
   {
-    QPixmap *pixmap = nullptr;
-    if ( !QPixmapCache::find( entry, pixmap ) || !pixmap )
+    QPixmap pixmap;
+    if ( !QPixmapCache::find( entry, &pixmap ) )
     {
       QPixmap newPixmap = createPreview( entry );
       QPixmapCache::insert( entry, newPixmap );
       return newPixmap;
     }
     else
     {
-      return *pixmap;
+      return pixmap;
     }
   }
   else if ( role == Qt::UserRole || role == Qt::ToolTipRole )
@@ -771,5 +771,3 @@ void QgsSvgParameterValueDelegate::updateEditorGeometry( QWidget *editor, const
 }
 
 ///@endcond
-
-

src/gui/symbology/qgssvgselectorwidget.h

@@ -343,6 +343,7 @@ class GUI_EXPORT QgsSvgSelectorListModel : public QAbstractListModel
      */
     void addSvgs( const QStringList &svgs );
 
+    friend class TestQgsSvgSelectorWidget;
 };
 
 

tests/src/gui/CMakeLists.txt

@@ -77,6 +77,7 @@ set(TESTS
   testqgsqueryresultwidget.cpp
   testqgscompoundcolorwidget.cpp
   testqgsmaskingwidget.cpp
+  testqgssvgselectorwidget.cpp
 )
 
 foreach(TESTSRC ${TESTS})

tests/src/gui/testqgssvgselectorwidget.cpp

@@ -0,0 +1,78 @@
+/***************************************************************************
+    testqgssvgselectorwidget.cpp
+    ---------------------
+    begin                : 2024/09/25
+    copyright            : (C) 2024 by Julien Cabieces
+    email                : julien dot cabieces at oslandia 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 <QPixmapCache>
+#include <QTemporaryFile>
+
+#include "qgstest.h"
+#include "qgssvgselectorwidget.h"
+
+class TestQgsSvgSelectorWidget : public QgsTest
+{
+    Q_OBJECT
+
+  public:
+
+    TestQgsSvgSelectorWidget() : QgsTest( QStringLiteral( "SVG Selector Widget Tests" ) ) {}
+
+  private slots:
+    void initTestCase();// will be called before the first testfunction is executed.
+    void cleanupTestCase();// will be called after the last testfunction was executed.
+    void init();// will be called before each testfunction is executed.
+    void cleanup();// will be called after every testfunction.
+    void testPixmapCache();
+};
+
+void TestQgsSvgSelectorWidget::initTestCase()
+{
+  QgsApplication::init();
+  QgsApplication::initQgis();
+}
+
+void TestQgsSvgSelectorWidget::cleanupTestCase()
+{
+  QgsApplication::exitQgis();
+}
+
+void TestQgsSvgSelectorWidget::init()
+{
+}
+
+void TestQgsSvgSelectorWidget::cleanup()
+{
+}
+
+void TestQgsSvgSelectorWidget::testPixmapCache()
+{
+  // We want to check that QPixmapCache is correctly used
+  // So we force a cache image different from the one we set to the model to check that this is
+  // the cache image returned, not the model svg one
+
+  const QPixmap cachePixmap( QStringLiteral( "%1/rgb256x256.png" ).arg( TEST_DATA_DIR ) );
+  const QString sampleSvg = QStringLiteral( "%1/sample_svg.svg" ).arg( TEST_DATA_DIR );
+  QPixmapCache::insert( sampleSvg, cachePixmap );
+
+  QgsSvgSelectorListModel model( nullptr );
+  model.addSvgs( QStringList() << sampleSvg );
+
+  const QPixmap pixmap = model.data( model.index( 0, 0 ), Qt::DecorationRole ).value<QPixmap>();
+  QVERIFY( !pixmap.isNull() );
+
+  QCOMPARE( pixmap, cachePixmap );
+}
+
+
+QGSTEST_MAIN( TestQgsSvgSelectorWidget )
+#include "testqgssvgselectorwidget.moc"