Prevent synced view scale from going to 0 when resizing synced docks

nyalldawson · nyalldawson · commit 946a9d0e8575 · 2017-03-14T10:31:04.000+10:00
diff --git a/src/app/qgsmapcanvasdockwidget.cpp b/src/app/qgsmapcanvasdockwidget.cpp
@@ -163,6 +163,13 @@ QgsMapCanvasDockWidget::QgsMapCanvasDockWidget( const QString &name, QWidget *pa
       mBlockMagnificationUpdate = false;
     }
   } );
+
+  mResizeTimer.setSingleShot( true );
+  connect( &mResizeTimer, &QTimer::timeout, this, [ = ]
+  {
+    mBlockExtentSync = false;
+    syncViewExtent( mMainCanvas );
+  } );
 }
 
 QgsMapCanvas *QgsMapCanvasDockWidget::mapCanvas()
@@ -180,6 +187,12 @@ bool QgsMapCanvasDockWidget::isViewExtentSynchronized() const
   return mActionSyncView->isChecked();
 }
 
+void QgsMapCanvasDockWidget::resizeEvent( QResizeEvent * )
+{
+  mBlockExtentSync = true;
+  mResizeTimer.start( 500 );
+}
+
 void QgsMapCanvasDockWidget::setMapCrs()
 {
   QgsProjectionSelectionDialog dlg;
@@ -209,7 +222,7 @@ void QgsMapCanvasDockWidget::syncView( bool enabled )
 void QgsMapCanvasDockWidget::syncViewExtent( QgsMapCanvas *sourceCanvas )
 {
   // avoid infinite recursion
-  syncView( false );
+  mBlockExtentSync = true;
 
   QgsMapCanvas *destCanvas = sourceCanvas == mMapCanvas ? mMainCanvas : mMapCanvas;
 
@@ -226,11 +239,14 @@ void QgsMapCanvasDockWidget::syncViewExtent( QgsMapCanvas *sourceCanvas )
   }
   destCanvas->refresh();
 
-  syncView( true );
+  mBlockExtentSync = false;
 }
 
 void QgsMapCanvasDockWidget::mapExtentChanged()
 {
+  if ( mBlockExtentSync )
+    return;
+
   QgsMapCanvas *sourceCanvas = qobject_cast< QgsMapCanvas * >( sender() );
   if ( !sourceCanvas )
     return;
diff --git a/src/app/qgsmapcanvasdockwidget.h b/src/app/qgsmapcanvasdockwidget.h
@@ -20,6 +20,7 @@
 #include "qgsdockwidget.h"
 #include "qgis_app.h"
 #include <QWidgetAction>
+#include <QTimer>
 #include <memory>
 
 class QgsMapCanvas;
@@ -60,6 +61,10 @@ class APP_EXPORT QgsMapCanvasDockWidget : public QgsDockWidget, private Ui::QgsM
 
     void renameTriggered();
 
+  protected:
+
+    void resizeEvent( QResizeEvent *e ) override;
+
   private slots:
 
     void setMapCrs();
@@ -81,7 +86,9 @@ class APP_EXPORT QgsMapCanvasDockWidget : public QgsDockWidget, private Ui::QgsM
     bool mBlockScaleUpdate = false;
     bool mBlockRotationUpdate = false;
     bool mBlockMagnificationUpdate = false;
+    bool mBlockExtentSync = false;
     QgsMapToolPan *mPanTool = nullptr;
+    QTimer mResizeTimer;
     void syncViewExtent( QgsMapCanvas *sourceCanvas );
 };
 

Original file line number	Diff line number	Diff line change
`@@ -163,6 +163,13 @@ QgsMapCanvasDockWidget::QgsMapCanvasDockWidget( const QString &name, QWidget *pa`
`163`	`163`	`mBlockMagnificationUpdate = false;`
`164`	`164`	`}`
`165`	`165`	`} );`
	`166`	`+`
	`167`	`+ mResizeTimer.setSingleShot( true );`
	`168`	`+ connect( &mResizeTimer, &QTimer::timeout, this, [ = ]`
	`169`	`+ {`
	`170`	`+ mBlockExtentSync = false;`
	`171`	`+ syncViewExtent( mMainCanvas );`
	`172`	`+ } );`
`166`	`173`	`}`
`167`	`174`
`168`	`175`	`QgsMapCanvas *QgsMapCanvasDockWidget::mapCanvas()`
`@@ -180,6 +187,12 @@ bool QgsMapCanvasDockWidget::isViewExtentSynchronized() const`
`180`	`187`	`return mActionSyncView->isChecked();`
`181`	`188`	`}`
`182`	`189`
	`190`	`+void QgsMapCanvasDockWidget::resizeEvent( QResizeEvent * )`
	`191`	`+{`
	`192`	`+ mBlockExtentSync = true;`
	`193`	`+ mResizeTimer.start( 500 );`
	`194`	`+}`
	`195`	`+`
`183`	`196`	`void QgsMapCanvasDockWidget::setMapCrs()`
`184`	`197`	`{`
`185`	`198`	`QgsProjectionSelectionDialog dlg;`
`@@ -209,7 +222,7 @@ void QgsMapCanvasDockWidget::syncView( bool enabled )`
`209`	`222`	`void QgsMapCanvasDockWidget::syncViewExtent( QgsMapCanvas *sourceCanvas )`
`210`	`223`	`{`
`211`	`224`	`// avoid infinite recursion`
`212`		`- syncView( false );`
	`225`	`+ mBlockExtentSync = true;`
`213`	`226`
`214`	`227`	`QgsMapCanvas *destCanvas = sourceCanvas == mMapCanvas ? mMainCanvas : mMapCanvas;`
`215`	`228`
`@@ -226,11 +239,14 @@ void QgsMapCanvasDockWidget::syncViewExtent( QgsMapCanvas *sourceCanvas )`
`226`	`239`	`}`
`227`	`240`	`destCanvas->refresh();`
`228`	`241`
`229`		`- syncView( true );`
	`242`	`+ mBlockExtentSync = false;`
`230`	`243`	`}`
`231`	`244`
`232`	`245`	`void QgsMapCanvasDockWidget::mapExtentChanged()`
`233`	`246`	`{`
	`247`	`+ if ( mBlockExtentSync )`
	`248`	`+ return;`
	`249`	`+`
`234`	`250`	`QgsMapCanvas sourceCanvas = qobject_cast< QgsMapCanvas >( sender() );`
`235`	`251`	`if ( !sourceCanvas )`
`236`	`252`	`return;`