Show composer picture preview icons on demand

Author: mhugent

src/app/composer/qgscomposerpicturewidget.cpp

@@ -30,7 +30,7 @@
 #include <QSettings>
 #include <QSvgRenderer>
 
-QgsComposerPictureWidget::QgsComposerPictureWidget( QgsComposerPicture* picture ): QWidget(), mPicture( picture )
+QgsComposerPictureWidget::QgsComposerPictureWidget( QgsComposerPicture* picture ): QWidget(), mPicture( picture ), mPreviewInitialized( false )
 {
   setupUi( this );
 
@@ -44,8 +44,8 @@ QgsComposerPictureWidget::QgsComposerPictureWidget( QgsComposerPicture* picture
 
   mPreviewListWidget->setIconSize( QSize( 30, 30 ) );
 
-  //add preview icons
-  addStandardDirectoriesToPreview();
+  //add preview icons on demand in showEvent()
+
   connect( mPicture, SIGNAL( itemChanged() ), this, SLOT( setGuiElementValues() ) );
   connect( mPicture, SIGNAL( rotationChanged( double ) ), this, SLOT( setGuiElementValues() ) );
 }
@@ -263,6 +263,11 @@ void QgsComposerPictureWidget::on_mRotationFromComposerMapCheckBox_stateChanged(
 void QgsComposerPictureWidget::showEvent( QShowEvent * event )
 {
   refreshMapComboBox();
+  if ( !mPreviewInitialized )
+  {
+    addStandardDirectoriesToPreview();
+    mPreviewInitialized = true;
+  }
   QWidget::showEvent( event );
 }
 

src/app/composer/qgscomposerpicturewidget.h

@@ -54,6 +54,8 @@ class QgsComposerPictureWidget: public QWidget, private Ui::QgsComposerPictureWi
 
   private:
     QgsComposerPicture* mPicture;
+    bool mPreviewInitialized;
+
     /**Add the icons of a directory to the preview. Returns 0 in case of success*/
     int addDirectoryToPreview( const QString& path );
     /**Add the icons of the standard directories to the preview*/