Merge pull request #8247 from 3nids/maptoolzoom

fixes to the map tool zoom

python/gui/auto_generated/qgsmaptool.sip.in

@@ -116,6 +116,13 @@ the previously used toolbutton to pop out. *
     QAction *action();
 %Docstring
 Returns associated action with map tool or NULL if no action is associated
+%End
+
+    bool isActive() const;
+%Docstring
+Returns if the current map tool active on the map canvas
+
+.. versionadded:: 3.4
 %End
 
     void setButton( QAbstractButton *button );

python/gui/auto_generated/qgsmaptoolzoom.sip.in

@@ -34,13 +34,19 @@ constructor
 
     virtual void canvasReleaseEvent( QgsMapMouseEvent *e );
 
+    virtual void keyPressEvent( QKeyEvent *e );
+
+    virtual void keyReleaseEvent( QKeyEvent *e );
+
     virtual void deactivate();
 
 
   protected:
 
 
 
+
+
 };
 
 /************************************************************************

src/gui/qgsmaptool.cpp

@@ -130,6 +130,11 @@ QAction *QgsMapTool::action()
   return mAction;
 }
 
+bool QgsMapTool::isActive() const
+{
+  return mCanvas && mCanvas->mapTool() == this;
+}
+
 void QgsMapTool::setButton( QAbstractButton *button )
 {
   mButton = button;
@@ -143,6 +148,8 @@ QAbstractButton *QgsMapTool::button()
 void QgsMapTool::setCursor( const QCursor &cursor )
 {
   mCursor = cursor;
+  if ( isActive() )
+    mCanvas->setCursor( mCursor );
 }
 
 

src/gui/qgsmaptool.h

@@ -137,6 +137,12 @@ class GUI_EXPORT QgsMapTool : public QObject
     //! Returns associated action with map tool or NULL if no action is associated
     QAction *action();
 
+    /**
+     * Returns if the current map tool active on the map canvas
+     * \since QGIS 3.4
+     */
+    bool isActive() const;
+
     /**
      * Use this to associate a button to this maptool. It has the same meaning
      * as setAction() function except it works with a button instead of an QAction. */

src/gui/qgsmaptoolzoom.cpp

@@ -31,13 +31,14 @@
 QgsMapToolZoom::QgsMapToolZoom( QgsMapCanvas *canvas, bool zoomOut )
   : QgsMapTool( canvas )
   , mZoomOut( zoomOut )
+  , mNativeZoomOut( zoomOut )
   , mDragging( false )
+  , mZoomOutCursor( QgsApplication::getThemeCursor( QgsApplication::Cursor::ZoomOut ) )
+  , mZoomInCursor( QgsApplication::getThemeCursor( QgsApplication::Cursor::ZoomIn ) )
 
 {
   mToolName = tr( "Zoom" );
-  // set the cursor
-  mCursor = zoomOut ? QgsApplication::getThemeCursor( QgsApplication::Cursor::ZoomOut ) :
-            QgsApplication::getThemeCursor( QgsApplication::Cursor::ZoomIn );
+  updateCursor();
 }
 
 QgsMapToolZoom::~QgsMapToolZoom()
@@ -84,21 +85,20 @@ void QgsMapToolZoom::canvasReleaseEvent( QgsMapMouseEvent *e )
   if ( e->button() != Qt::LeftButton )
     return;
 
-  bool zoomOut = mZoomOut;
-  if ( e->modifiers() & Qt::AltModifier )
-    zoomOut = !zoomOut;
-
   // We are not really dragging in this case. This is sometimes caused by
   // a pen based computer reporting a press, move, and release, all the
   // one point.
-  if ( mDragging && ( mZoomRect.topLeft() == mZoomRect.bottomRight() ) )
+  bool tooShort = ( mZoomRect.topLeft() - mZoomRect.bottomRight() ).manhattanLength() < mMinPixelZoom;
+  if ( !mDragging || tooShort )
   {
     mDragging = false;
     delete mRubberBand;
     mRubberBand = nullptr;
-  }
 
-  if ( mDragging )
+    // change to zoom in/out by the default multiple
+    mCanvas->zoomWithCenter( e->x(), e->y(), !mZoomOut );
+  }
+  else
   {
     mDragging = false;
     delete mRubberBand;
@@ -122,15 +122,10 @@ void QgsMapToolZoom::canvasReleaseEvent( QgsMapMouseEvent *e )
     const QgsMapToPixel *m2p = mCanvas->getCoordinateTransform();
     QgsPointXY c = m2p->toMapCoordinates( mZoomRect.center() );
 
-    mCanvas->zoomByFactor( zoomOut ? 1.0 / sf : sf, &c );
+    mCanvas->zoomByFactor( mZoomOut ? 1.0 / sf : sf, &c );
 
     mCanvas->refresh();
   }
-  else // not dragging
-  {
-    // change to zoom in/out by the default multiple
-    mCanvas->zoomWithCenter( e->x(), e->y(), !zoomOut );
-  }
 }
 
 void QgsMapToolZoom::deactivate()
@@ -140,3 +135,31 @@ void QgsMapToolZoom::deactivate()
 
   QgsMapTool::deactivate();
 }
+
+void QgsMapToolZoom::updateCursor()
+{
+  setCursor( mZoomOut ? mZoomOutCursor : mZoomInCursor );
+}
+
+void QgsMapToolZoom::keyPressEvent( QKeyEvent *e )
+{
+  if ( e->key() == Qt::Key_Alt )
+  {
+    mZoomOut = !mZoomOut;
+    updateCursor();
+  }
+}
+
+void QgsMapToolZoom::keyReleaseEvent( QKeyEvent *e )
+{
+  // key press events are not caught wile the mouse is pressed
+  // so we can't mess if we are already dragging
+  // we need to go back to native state, as it cannot be determine
+  // (since the press event is not detected while mouse is pressed)
+
+  if ( e->key() == Qt::Key_Alt )
+  {
+    mZoomOut = mNativeZoomOut;
+    updateCursor();
+  }
+}

src/gui/qgsmaptoolzoom.h

@@ -40,19 +40,31 @@ class GUI_EXPORT QgsMapToolZoom : public QgsMapTool
     void canvasMoveEvent( QgsMapMouseEvent *e ) override;
     void canvasPressEvent( QgsMapMouseEvent *e ) override;
     void canvasReleaseEvent( QgsMapMouseEvent *e ) override;
+    void keyPressEvent( QKeyEvent *e ) override;
+    void keyReleaseEvent( QKeyEvent *e ) override;
     void deactivate() override;
 
   protected:
     //! stores actual zoom rect
     QRect mZoomRect;
+    // minimum pixel size of diagonal of the zoom rectangle
+    int mMinPixelZoom = 20;
 
     //! indicates whether we're zooming in or out
     bool mZoomOut;
+    //! native tool
+    bool mNativeZoomOut;
 
     //! Flag to indicate a map canvas drag operation is taking place
     bool mDragging;
 
     QgsRubberBand *mRubberBand = nullptr;
+
+    QCursor mZoomOutCursor;
+    QCursor mZoomInCursor;
+
+  private:
+    void updateCursor();
 };
 
 #endif