[api] Add signal to QgsLayoutDesignerInterface which is emitted

whenever a map item's preview image has been refreshed inside the designer
qgis · Jun 9, 2021 · ccb4146 · ccb4146
1 parent 309a2a6
commit ccb4146
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diff --git a/python/core/auto_generated/layout/qgslayoutitemmap.sip.in b/python/core/auto_generated/layout/qgslayoutitemmap.sip.in
@@ -1009,6 +1009,13 @@ Emitted when the map's associated ``theme`` is changed.
 Emitted when the map's coordinate reference system is changed.
 
 .. versionadded:: 3.18
+%End
+
+    void previewRefreshed();
+%Docstring
+Emitted whenever the item's map preview has been refreshed.
+
+.. versionadded:: 3.20
 %End
 
   public slots:

diff --git a/python/gui/auto_generated/layout/qgslayoutdesignerinterface.sip.in b/python/gui/auto_generated/layout/qgslayoutdesignerinterface.sip.in
@@ -465,6 +465,14 @@ Emitted whenever a layout is exported from the layout designer.
 
 The results of the export can be retrieved by calling :py:func:`~QgsLayoutDesignerInterface.lastExportResults`.
 
+.. versionadded:: 3.20
+%End
+
+
+    void mapPreviewRefreshed( QgsLayoutItemMap *map );
+%Docstring
+Emitted when a ``map`` item's preview has been refreshed.
+
 .. versionadded:: 3.20
 %End
 

diff --git a/src/app/layout/qgslayoutdesignerdialog.cpp b/src/app/layout/qgslayoutdesignerdialog.cpp
@@ -115,6 +115,7 @@ QgsAppLayoutDesignerInterface::QgsAppLayoutDesignerInterface( QgsLayoutDesignerD
   , mDesigner( dialog )
 {
   connect( mDesigner, &QgsLayoutDesignerDialog::layoutExported, this, &QgsLayoutDesignerInterface::layoutExported );
+  connect( mDesigner, &QgsLayoutDesignerDialog::mapPreviewRefreshed, this, &QgsLayoutDesignerInterface::mapPreviewRefreshed );
 }
 
 QWidget *QgsAppLayoutDesignerInterface::window()
@@ -1210,6 +1211,13 @@ void QgsLayoutDesignerDialog::setCurrentLayout( QgsLayout *layout )
     if ( mLayout )
     {
       disconnect( mLayout, &QgsLayout::backgroundTaskCountChanged, this, &QgsLayoutDesignerDialog::backgroundTaskCountChanged );
+      QList< QgsLayoutItemMap * > maps;
+      mLayout->layoutItems( maps );
+      for ( QgsLayoutItemMap *map : std::as_const( maps ) )
+      {
+        disconnect( map, &QgsLayoutItemMap::previewRefreshed, this, &QgsLayoutDesignerDialog::onMapPreviewRefreshed );
+      }
+      disconnect( mLayout, &QgsLayout::itemAdded, this, &QgsLayoutDesignerDialog::onItemAdded );
     }
 
     layout->deselectAll();
@@ -1255,6 +1263,14 @@ void QgsLayoutDesignerDialog::setCurrentLayout( QgsLayout *layout )
 
     connect( mLayout, &QgsLayout::backgroundTaskCountChanged, this, &QgsLayoutDesignerDialog::backgroundTaskCountChanged );
 
+    QList< QgsLayoutItemMap * > maps;
+    mLayout->layoutItems( maps );
+    for ( QgsLayoutItemMap *map : std::as_const( maps ) )
+    {
+      connect( map, &QgsLayoutItemMap::previewRefreshed, this, &QgsLayoutDesignerDialog::onMapPreviewRefreshed );
+    }
+    connect( mLayout, &QgsLayout::itemAdded, this, &QgsLayoutDesignerDialog::onItemAdded );
+
     createLayoutPropertiesWidget();
     toggleActions( true );
   }
@@ -4891,6 +4907,23 @@ void QgsLayoutDesignerDialog::backgroundTaskCountChanged( int total )
   }
 }
 
+void QgsLayoutDesignerDialog::onMapPreviewRefreshed()
+{
+  QgsLayoutItemMap *map = qobject_cast< QgsLayoutItemMap * >( sender() );
+  if ( !map )
+    return;
+
+  emit mapPreviewRefreshed( map );
+}
+
+void QgsLayoutDesignerDialog::onItemAdded( QgsLayoutItem *item )
+{
+  if ( QgsLayoutItemMap *map = qobject_cast< QgsLayoutItemMap * >( item ) )
+  {
+    connect( map, &QgsLayoutItemMap::previewRefreshed, this, &QgsLayoutDesignerDialog::onMapPreviewRefreshed );
+  }
+}
+
 void QgsLayoutDesignerDialog::storeExportResults( QgsLayoutExporter::ExportResult result, QgsLayoutExporter *exporter )
 {
   mLastExportResults = std::make_unique< QgsLayoutDesignerInterface::ExportResults >();

diff --git a/src/app/layout/qgslayoutdesignerdialog.h b/src/app/layout/qgslayoutdesignerdialog.h
@@ -344,6 +344,11 @@ class QgsLayoutDesignerDialog: public QMainWindow, public Ui::QgsLayoutDesignerB
      */
     void layoutExported();
 
+    /**
+     * Emitted when a \a map preview has been refreshed.
+     */
+    void mapPreviewRefreshed( QgsLayoutItemMap *map );
+
   protected:
 
     void closeEvent( QCloseEvent * ) override;
@@ -410,6 +415,8 @@ class QgsLayoutDesignerDialog: public QMainWindow, public Ui::QgsLayoutDesignerB
     void updateWindowTitle();
 
     void backgroundTaskCountChanged( int total );
+    void onMapPreviewRefreshed();
+    void onItemAdded( QgsLayoutItem *item );
 
   private:
 

diff --git a/src/core/layout/qgslayoutitemmap.cpp b/src/core/layout/qgslayoutitemmap.cpp
@@ -1971,6 +1971,7 @@ void QgsLayoutItemMap::painterJobFinished()
   mLastRenderedImageOffsetY = 0;
   emit backgroundTaskCountChanged( 0 );
   update();
+  emit previewRefreshed();
 }
 
 void QgsLayoutItemMap::shapeChanged()

diff --git a/src/core/layout/qgslayoutitemmap.h b/src/core/layout/qgslayoutitemmap.h
@@ -929,6 +929,13 @@ class CORE_EXPORT QgsLayoutItemMap : public QgsLayoutItem, public QgsTemporalRan
      */
     void crsChanged();
 
+    /**
+     * Emitted whenever the item's map preview has been refreshed.
+     *
+     * \since QGIS 3.20
+     */
+    void previewRefreshed();
+
   public slots:
 
     void refresh() override;

diff --git a/src/gui/layout/qgslayoutdesignerinterface.h b/src/gui/layout/qgslayoutdesignerinterface.h
@@ -409,6 +409,14 @@ class GUI_EXPORT QgsLayoutDesignerInterface: public QObject
      */
     void layoutExported();
 
+
+    /**
+     * Emitted when a \a map item's preview has been refreshed.
+     *
+     * \since QGIS 3.20
+     */
+    void mapPreviewRefreshed( QgsLayoutItemMap *map );
+
 };
 
 #endif // QGSLAYOUTDESIGNERINTERFACE_H