Emit signal when showing / hiding composer

Author: mhugent

python/gui/qgscomposerview.sip

@@ -107,4 +107,9 @@ class QgsComposerView: QGraphicsView
     /**Current action (e.g. adding composer map) has been finished. The purpose of this signal is that
      QgsComposer may set the selection tool again*/
     void actionFinished();
+
+    /**Emitted before composerview is shown*/
+    void composerViewShow( QgsComposerView* );
+    /**Emitted before composerview is hidden*/
+    void composerViewHide( QgsComposerView* );
 };

src/gui/qgscomposerview.cpp

@@ -29,6 +29,7 @@
 #include "qgscomposerscalebar.h"
 #include "qgscomposershape.h"
 #include "qgscomposerattributetable.h"
+#include "qgslogger.h"
 
 QgsComposerView::QgsComposerView( QWidget* parent, const char* name, Qt::WFlags f )
     : QGraphicsView( parent )
@@ -499,6 +500,18 @@ void QgsComposerView::paintEvent( QPaintEvent* event )
   }
 }
 
+void QgsComposerView::hideEvent( QHideEvent* e )
+{
+  emit( composerViewShow( this ) );
+  e->ignore();
+}
+
+void QgsComposerView::showEvent( QShowEvent* e )
+{
+  emit( composerViewHide( this ) );
+  e->ignore();
+}
+
 void QgsComposerView::setComposition( QgsComposition* c )
 {
   setScene( c );

src/gui/qgscomposerview.h

@@ -117,6 +117,8 @@ class GUI_EXPORT QgsComposerView: public QGraphicsView
 
     void paintEvent( QPaintEvent* event );
 
+    void hideEvent( QHideEvent* e );
+    void showEvent( QShowEvent* e );
 
   private:
     /**Status of shift key (used for multiple selection)*/
@@ -167,6 +169,11 @@ class GUI_EXPORT QgsComposerView: public QGraphicsView
     /**Current action (e.g. adding composer map) has been finished. The purpose of this signal is that
      QgsComposer may set the selection tool again*/
     void actionFinished();
+
+    /**Emitted before composerview is shown*/
+    void composerViewShow( QgsComposerView* );
+    /**Emitted before composerview is hidden*/
+    void composerViewHide( QgsComposerView* );
 };
 
 #endif