Add refresh action for layouts

python/core/layout/qgslayout.sip

@@ -419,6 +419,16 @@ class QgsLayout : QGraphicsScene, QgsExpressionContextGenerator, QgsLayoutUndoOb
 
   public slots:
 
+    void refresh();
+%Docstring
+ Forces the layout, and all items contained within it, to refresh. For instance, this causes maps to redraw
+ and rebuild cached images, html items to reload their source url, and attribute tables
+ to refresh their contents. Calling this also triggers a recalculation of all data defined
+ attributes within the layout.
+
+.. seealso:: refreshed()
+%End
+
     void updateBounds();
 %Docstring
  Updates the scene bounds of the layout.
@@ -437,6 +447,12 @@ class QgsLayout : QGraphicsScene, QgsExpressionContextGenerator, QgsLayoutUndoOb
  If None, no item is selected.
 %End
 
+    void refreshed();
+%Docstring
+ Is emitted when the layout has been refreshed and items should also be refreshed
+ and updated.
+%End
+
 };
 
 

src/app/layout/qgslayoutdesignerdialog.cpp

@@ -142,6 +142,8 @@ QgsLayoutDesignerDialog::QgsLayoutDesignerDialog( QWidget *parent, Qt::WindowFla
   mHorizontalRuler->setContextMenu( rulerMenu );
   mVerticalRuler->setContextMenu( rulerMenu );
 
+  connect( mActionRefreshView, &QAction::triggered, this, &QgsLayoutDesignerDialog::refreshLayout );
+
   connect( mActionShowGrid, &QAction::triggered, this, &QgsLayoutDesignerDialog::showGrid );
   connect( mActionSnapGrid, &QAction::triggered, this, &QgsLayoutDesignerDialog::snapToGrid );
 
@@ -809,6 +811,28 @@ void QgsLayoutDesignerDialog::moveSelectedItemsToBottom()
   mView->moveSelectedItemsToBottom();
 }
 
+void QgsLayoutDesignerDialog::refreshLayout()
+{
+  if ( !currentLayout() )
+  {
+    return;
+  }
+
+#if 0 //TODO
+  //refresh atlas feature first, to update attributes
+  if ( mComposition->atlasMode() == QgsComposition::PreviewAtlas )
+  {
+    //block signals from atlas, since the later call to mComposition->refreshItems() will
+    //also trigger items to refresh atlas dependent properties
+    mComposition->atlasComposition().blockSignals( true );
+    mComposition->atlasComposition().refreshFeature();
+    mComposition->atlasComposition().blockSignals( false );
+  }
+#endif
+
+  currentLayout()->refresh();
+}
+
 void QgsLayoutDesignerDialog::closeEvent( QCloseEvent * )
 {
   emit aboutToClose();

src/app/layout/qgslayoutdesignerdialog.h

@@ -205,6 +205,14 @@ class QgsLayoutDesignerDialog: public QMainWindow, private Ui::QgsLayoutDesigner
      */
     void moveSelectedItemsToBottom();
 
+    /**
+     * Forces the layout, and all items contained within it, to refresh. For instance, this causes maps to redraw
+     * and rebuild cached images, html items to reload their source url, and attribute tables
+     * to refresh their contents. Calling this also triggers a recalculation of all data defined
+     * attributes within the layout.
+     */
+    void refreshLayout();
+
   signals:
 
     /**

src/core/layout/qgslayout.cpp

@@ -518,6 +518,12 @@ QList<QgsLayoutItem *> QgsLayout::ungroupItems( QgsLayoutItemGroup *group )
   return ungroupedItems;
 }
 
+void QgsLayout::refresh()
+{
+  emit refreshed();
+  update();
+}
+
 void QgsLayout::writeXmlLayoutSettings( QDomElement &element, QDomDocument &document, const QgsReadWriteContext & ) const
 {
   mCustomProperties.writeXml( element, document );

src/core/layout/qgslayout.h

@@ -467,6 +467,16 @@ class CORE_EXPORT QgsLayout : public QGraphicsScene, public QgsExpressionContext
 
   public slots:
 
+    /**
+     * Forces the layout, and all items contained within it, to refresh. For instance, this causes maps to redraw
+     * and rebuild cached images, html items to reload their source url, and attribute tables
+     * to refresh their contents. Calling this also triggers a recalculation of all data defined
+     * attributes within the layout.
+     *
+     * \see refreshed()
+     */
+    void refresh();
+
     /**
      * Updates the scene bounds of the layout.
      */
@@ -485,6 +495,12 @@ class CORE_EXPORT QgsLayout : public QGraphicsScene, public QgsExpressionContext
      */
     void selectedItemChanged( QgsLayoutItem *selected );
 
+    /**
+     * Is emitted when the layout has been refreshed and items should also be refreshed
+     * and updated.
+     */
+    void refreshed();
+
   private:
 
     QgsProject *mProject = nullptr;

src/core/layout/qgslayoutobject.cpp

@@ -88,6 +88,11 @@ QgsLayoutObject::QgsLayoutObject( QgsLayout *layout )
   , mLayout( layout )
 {
   initPropertyDefinitions();
+
+  if ( mLayout )
+  {
+    connect( mLayout, &QgsLayout::refreshed, this, &QgsLayoutObject::refresh );
+  }
 }
 
 const QgsLayout *QgsLayoutObject::layout() const

src/ui/layout/qgslayoutdesignerbase.ui

@@ -124,6 +124,7 @@
      <addaction name="mActionPreviewProtanope"/>
      <addaction name="mActionPreviewDeuteranope"/>
     </widget>
+    <addaction name="mActionRefreshView"/>
     <addaction name="menuPreview"/>
     <addaction name="separator"/>
     <addaction name="mActionZoomIn"/>
@@ -238,6 +239,7 @@
    <addaction name="mActionZoomOut"/>
    <addaction name="mActionZoomActual"/>
    <addaction name="mActionZoomAll"/>
+   <addaction name="mActionRefreshView"/>
   </widget>
   <widget class="QToolBar" name="mActionsToolbar">
    <property name="windowTitle">
@@ -992,6 +994,21 @@
     <string>Ctrl+Shift+G</string>
    </property>
   </action>
+  <action name="mActionRefreshView">
+   <property name="icon">
+    <iconset resource="../../../images/images.qrc">
+     <normaloff>:/images/themes/default/mActionDraw.svg</normaloff>:/images/themes/default/mActionDraw.svg</iconset>
+   </property>
+   <property name="text">
+    <string>&amp;Refresh</string>
+   </property>
+   <property name="toolTip">
+    <string>Refresh view</string>
+   </property>
+   <property name="shortcut">
+    <string>F5</string>
+   </property>
+  </action>
  </widget>
  <resources>
   <include location="../../../images/images.qrc"/>