[composer] Update number of pages in gui whenever number of pages is changed by multi frame items (sponsored by City of Uster, Switzerland)

Author: nyalldawson

src/app/composer/qgscompositionwidget.cpp

@@ -47,6 +47,7 @@ QgsCompositionWidget::QgsCompositionWidget( QWidget* parent, QgsComposition* c )
   if ( mComposition )
   {
     mNumPagesSpinBox->setValue( mComposition->numPages() );
+    connect( mComposition, SIGNAL( nPagesChanged() ), this, SLOT( setNumberPages() ) );
 
     updatePageStyle();
 
@@ -431,6 +432,18 @@ void QgsCompositionWidget::setPrintAsRasterCheckBox( bool state )
   mPrintAsRasterCheckBox->blockSignals( false );
 }
 
+void QgsCompositionWidget::setNumberPages()
+{
+  if ( !mComposition )
+  {
+    return;
+  }
+
+  mNumPagesSpinBox->blockSignals( true );
+  mNumPagesSpinBox->setValue( mComposition->numPages() );
+  mNumPagesSpinBox->blockSignals( false );
+}
+
 void QgsCompositionWidget::displaySnapingSettings()
 {
   if ( !mComposition )

src/app/composer/qgscompositionwidget.h

@@ -64,6 +64,8 @@ class QgsCompositionWidget: public QWidget, private Ui::QgsCompositionWidgetBase
     void displayCompositionWidthHeight();
     /**Sets Print as raster checkbox value*/
     void setPrintAsRasterCheckBox( bool state );
+    /**Sets number of pages spin box value*/
+    void setNumberPages();
 
   signals:
     /**Is emitted when page orientation changes*/