Added functionality to lock a map canvas to prevent user interaction so that the overview canvas cant be misused,

e.g.:
  mOverviewCanvas->userInteractionAllowed(false);

This fixes bug: 977032

Fix "overview does not zoom to all when layer removed" bug [ 977034 ]

Fixed overview paints multiple times bug 977015


git-svn-id: http://svn.osgeo.org/qgis/trunk@1686 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/qgisapp.cpp

@@ -300,6 +300,8 @@ QgisApp::QgisApp(QWidget * parent, const char *name, WFlags fl):QgisAppBase(pare
   mMapLegend->setSorting(-1);
 
   mOverviewCanvas = new QgsMapCanvas(legendOverviewSplit);
+  // lock the canvas to prevent user interaction
+  mOverviewCanvas->userInteractionAllowed(false);
   // mL = new QScrollView(canvasLegendSplit);
   //add a canvas
   mMapCanvas = new QgsMapCanvas(canvasLegendSplit);
@@ -1742,6 +1744,7 @@ void QgisApp::removeLayer()
   mMapLayerRegistry->removeMapLayer(layer->getLayerID());
   mOverviewCanvas->freeze(false);
   // draw the map
+  mOverviewCanvas->zoomFullExtent();
   mOverviewCanvas->clear();
   mOverviewCanvas->render();
   mMapCanvas->freeze(false);

src/qgsmapcanvas.cpp

@@ -207,6 +207,8 @@ QgsMapCanvas::QgsMapCanvas(QWidget * parent, const char *name)
     : QWidget(parent, name), mCanvasProperties( new CanvasProperties(width(), height()) )
 {
   setEraseColor(mCanvasProperties->bgColor);
+  //by default we allow a user to interact with the canvas
+  mUserInteractionAllowed=true;
   setMouseTracking(true);
   setFocusPolicy(QWidget::StrongFocus);
   QPaintDeviceMetrics *pdm = new QPaintDeviceMetrics(this);
@@ -733,6 +735,7 @@ void QgsMapCanvas::zoomToSelected()
 
 void QgsMapCanvas::mousePressEvent(QMouseEvent * e)
 {
+  if (!mUserInteractionAllowed) return;
   mCanvasProperties->mouseButtonDown = true;
   mCanvasProperties->boxStartPoint = e->pos();
 
@@ -752,6 +755,7 @@ void QgsMapCanvas::mousePressEvent(QMouseEvent * e)
 
 void QgsMapCanvas::mouseReleaseEvent(QMouseEvent * e)
 {
+  if (!mUserInteractionAllowed) return;
   QPainter paint;
   QPen     pen(Qt::gray);
   QgsPoint ll, ur;
@@ -974,6 +978,7 @@ void QgsMapCanvas::resizeEvent(QResizeEvent * e)
 
 void QgsMapCanvas::mouseMoveEvent(QMouseEvent * e)
 {
+  if (!mUserInteractionAllowed) return;
     // XXX magic numbers BAD -- 513?
   if (e->state() == Qt::LeftButton || e->state() == 513)
     {
@@ -1266,6 +1271,17 @@ std::list < QString >       & QgsMapCanvas::zOrders()
     return mCanvasProperties->zOrder;
 } // zOrders
 
+//! determines whether the user can interact with the overview canvas.
+void QgsMapCanvas::userInteractionAllowed(bool theFlag)
+{
+  mUserInteractionAllowed = theFlag;
+}
+//! determines whether the user can interact with the overview canvas.
+bool QgsMapCanvas::isUserInteractionAllowed()
+{
+  return mUserInteractionAllowed;
+}
+
 
 double QgsMapCanvas::mupp() const
 {

src/qgsmapcanvas.h

@@ -185,6 +185,11 @@ public slots:
     //! sets z order based on order of layers in the legend
     void setZOrderFromLegend(QgsLegend *lv);
 
+    //! determines whether the user can interact with the overview canvas.
+    void userInteractionAllowed(bool);
+    //! accessor to flag indicating whether the user can interact with the canvase
+    bool isUserInteractionAllowed();
+
 signals:
     /** Let the owner know how far we are with render operations */
     void setProgress(int,int);
@@ -261,6 +266,9 @@ private:
     //! true if canvas currently drawing
     bool isDrawing();
 
+    //! detrmines whether the user can interact with the canvas using a mouse
+    //(useful for locking the overview canvas)
+    bool mUserInteractionAllowed;
 }; // class QgsMapCanvas
 
 #endif