[FEATURE] Add option to use colour preview modes (grayscale, colour blindess) in map canvas (fix #9886)

python/gui/qgsmapcanvas.sip

@@ -263,6 +263,36 @@ class QgsMapCanvas : QGraphicsView
 
     //! returns last position of mouse cursor
     QPoint mouseLastXY();
+	
+    /** Enables a preview mode for the map canvas
+     * @param previewEnabled set to true to enable a preview mode
+     * @see setPreviewMode
+     * @note added in 2.3 */
+    void setPreviewModeEnabled( bool previewEnabled );
+
+    /** Returns whether a preview mode is enabled for the map canvas
+     * @returns true if a preview mode is currently enabled
+     * @see setPreviewModeEnabled
+     * @see previewMode
+     * @note added in 2.3 */
+    bool previewModeEnabled() const;
+
+    /** Sets a preview mode for the map canvas. This setting only has an effect if
+     * previewModeEnabled is true.
+     * @param mode preview mode for the canvas
+     * @see previewMode
+     * @see setPreviewModeEnabled
+     * @see previewModeEnabled
+     * @note added in 2.3 */
+    void setPreviewMode( QgsPreviewEffect::PreviewMode mode );
+
+    /** Returns the current preview mode for the map canvas. This setting only has an effect if
+     * previewModeEnabled is true.
+     * @returns preview mode for map canvas
+     * @see setPreviewMode
+     * @see previewModeEnabled
+     * @note added in 2.3 */
+    QgsPreviewEffect::PreviewMode previewMode() const;	
 
   public slots:
 

src/app/qgisapp.cpp

@@ -1287,6 +1287,16 @@ void QgisApp::createActionGroups()
   mMapToolGroup->addAction( mActionMoveLabel );
   mMapToolGroup->addAction( mActionRotateLabel );
   mMapToolGroup->addAction( mActionChangeLabelProperties );
+
+  //
+  // Preview Modes Group
+  QActionGroup* mPreviewGroup = new QActionGroup( this );
+  mPreviewGroup->setExclusive( true );
+  mActionPreviewModeOff->setActionGroup( mPreviewGroup );
+  mActionPreviewModeGrayscale->setActionGroup( mPreviewGroup );
+  mActionPreviewModeMono->setActionGroup( mPreviewGroup );
+  mActionPreviewProtanope->setActionGroup( mPreviewGroup );
+  mActionPreviewDeuteranope->setActionGroup( mPreviewGroup );
 }
 
 void QgisApp::setAppStyleSheet( const QString& stylesheet )
@@ -1960,6 +1970,13 @@ void QgisApp::setupConnections()
   connect( this, SIGNAL( projectRead() ),
            this, SLOT( fileOpenedOKAfterLaunch() ) );
 
+  // connect preview modes actions
+  connect( mActionPreviewModeOff, SIGNAL( triggered() ), this, SLOT( disablePreviewMode() ) );
+  connect( mActionPreviewModeGrayscale, SIGNAL( triggered() ), this, SLOT( activateGrayscalePreview() ) );
+  connect( mActionPreviewModeMono, SIGNAL( triggered() ), this, SLOT( activateMonoPreview() ) );
+  connect( mActionPreviewProtanope, SIGNAL( triggered() ), this, SLOT( activateProtanopePreview() ) );
+  connect( mActionPreviewDeuteranope, SIGNAL( triggered() ), this, SLOT( activateDeuteranopePreview() ) );
+
   // handle deprecated labels in project for QGIS 2.0
   connect( this, SIGNAL( newProject() ),
            this, SLOT( checkForDeprecatedLabelsInProject() ) );
@@ -3959,6 +3976,35 @@ void QgisApp::deleteComposerManager()
   mComposerManager = 0;
 }
 
+void QgisApp::disablePreviewMode()
+{
+  mMapCanvas->setPreviewModeEnabled( false );
+}
+
+void QgisApp::activateGrayscalePreview()
+{
+  mMapCanvas->setPreviewModeEnabled( true );
+  mMapCanvas->setPreviewMode( QgsPreviewEffect::PreviewGrayscale );
+}
+
+void QgisApp::activateMonoPreview()
+{
+  mMapCanvas->setPreviewModeEnabled( true );
+  mMapCanvas->setPreviewMode( QgsPreviewEffect::PreviewMono );
+}
+
+void QgisApp::activateProtanopePreview()
+{
+  mMapCanvas->setPreviewModeEnabled( true );
+  mMapCanvas->setPreviewMode( QgsPreviewEffect::PreviewProtanope );
+}
+
+void QgisApp::activateDeuteranopePreview()
+{
+  mMapCanvas->setPreviewModeEnabled( true );
+  mMapCanvas->setPreviewMode( QgsPreviewEffect::PreviewDeuteranope );
+}
+
 void QgisApp::saveMapAsImage()
 {
   QPair< QString, QString> myFileNameAndFilter = QgisGui::getSaveAsImageName( this, tr( "Choose a file name to save the map image as" ) );

src/app/qgisapp.h

@@ -1189,6 +1189,22 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
     //! Deletes the active QgsComposerManager instance
     void deleteComposerManager();
 
+    /** Disable any preview modes shown on the map canvas
+     * @note added in 2.3 */
+    void disablePreviewMode();
+    /** Enable a grayscale preview mode on the map canvas
+     * @note added in 2.3 */
+    void activateGrayscalePreview();
+    /** Enable a monochrome preview mode on the map canvas
+     * @note added in 2.3 */
+    void activateMonoPreview();
+    /** Enable a color blindness (protanope) preview mode on the map canvas
+     * @note added in 2.3 */
+    void activateProtanopePreview();
+    /** Enable a color blindness (deuteranope) preview mode on the map canvas
+     * @note added in 2.3 */
+    void activateDeuteranopePreview();
+
   signals:
     /** emitted when a key is pressed and we want non widget sublasses to be able
       to pick up on this (e.g. maplayer) */
@@ -1343,6 +1359,7 @@ class APP_EXPORT QgisApp : public QMainWindow, private Ui::MainWindow
 
     // action groups ----------------------------------
     QActionGroup *mMapToolGroup;
+    QActionGroup *mPreviewGroup;
 
     // menus ------------------------------------------
 

src/gui/qgsmapcanvas.cpp

@@ -163,6 +163,7 @@ QgsMapCanvas::QgsMapCanvas( QWidget * parent, const char *name )
     , mUseParallelRendering( false )
     , mDrawRenderingStats( false )
     , mCache( 0 )
+    , mPreviewEffect( 0 )
 {
   setObjectName( name );
   mScene = new QGraphicsScene();
@@ -227,6 +228,9 @@ QgsMapCanvas::QgsMapCanvas( QWidget * parent, const char *name )
   viewport()->setAttribute( Qt::WA_AcceptTouchEvents );
 #endif
 
+  mPreviewEffect = new QgsPreviewEffect( this );
+  viewport()->setGraphicsEffect( mPreviewEffect );
+
   refresh();
 
 } // QgsMapCanvas ctor
@@ -1606,6 +1610,46 @@ QPoint QgsMapCanvas::mouseLastXY()
   return mCanvasProperties->mouseLastXY;
 }
 
+void QgsMapCanvas::setPreviewModeEnabled( bool previewEnabled )
+{
+  if ( !mPreviewEffect )
+  {
+    return;
+  }
+
+  mPreviewEffect->setEnabled( previewEnabled );
+}
+
+bool QgsMapCanvas::previewModeEnabled() const
+{
+  if ( !mPreviewEffect )
+  {
+    return false;
+  }
+
+  return mPreviewEffect->isEnabled();
+}
+
+void QgsMapCanvas::setPreviewMode( QgsPreviewEffect::PreviewMode mode )
+{
+  if ( !mPreviewEffect )
+  {
+    return;
+  }
+
+  mPreviewEffect->setMode( mode );
+}
+
+QgsPreviewEffect::PreviewMode QgsMapCanvas::previewMode() const
+{
+  if ( !mPreviewEffect )
+  {
+    return QgsPreviewEffect::PreviewGrayscale;
+  }
+
+  return mPreviewEffect->mode();
+}
+
 void QgsMapCanvas::readProject( const QDomDocument & doc )
 {
   QDomNodeList nodes = doc.elementsByTagName( "mapcanvas" );

src/gui/qgsmapcanvas.h

@@ -33,6 +33,7 @@
 #include <QtCore>
 
 #include "qgsmapsettings.h" // TEMPORARY
+#include "qgsprevieweffect.h" //for QgsPreviewEffect::PreviewMode
 
 #ifdef HAVE_TOUCH
 #include <QGestureEvent>
@@ -330,6 +331,36 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
     //! returns last position of mouse cursor
     QPoint mouseLastXY();
 
+    /** Enables a preview mode for the map canvas
+     * @param previewEnabled set to true to enable a preview mode
+     * @see setPreviewMode
+     * @note added in 2.3 */
+    void setPreviewModeEnabled( bool previewEnabled );
+
+    /** Returns whether a preview mode is enabled for the map canvas
+     * @returns true if a preview mode is currently enabled
+     * @see setPreviewModeEnabled
+     * @see previewMode
+     * @note added in 2.3 */
+    bool previewModeEnabled() const;
+
+    /** Sets a preview mode for the map canvas. This setting only has an effect if
+     * previewModeEnabled is true.
+     * @param mode preview mode for the canvas
+     * @see previewMode
+     * @see setPreviewModeEnabled
+     * @see previewModeEnabled
+     * @note added in 2.3 */
+    void setPreviewMode( QgsPreviewEffect::PreviewMode mode );
+
+    /** Returns the current preview mode for the map canvas. This setting only has an effect if
+     * previewModeEnabled is true.
+     * @returns preview mode for map canvas
+     * @see setPreviewMode
+     * @see previewModeEnabled
+     * @note added in 2.3 */
+    QgsPreviewEffect::PreviewMode previewMode() const;
+
   public slots:
 
     /**Repaints the canvas map*/
@@ -590,6 +621,9 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
 
 
     QTimer *mResizeTimer;
+
+    QgsPreviewEffect* mPreviewEffect;
+
 }; // class QgsMapCanvas
 
 

src/ui/qgisapp.ui

@@ -88,6 +88,16 @@
      <addaction name="mActionDecorationNorthArrow"/>
      <addaction name="mActionDecorationCopyright"/>
     </widget>
+    <widget class="QMenu" name="menuPreview_Mode">
+     <property name="title">
+      <string>Preview Mode</string>
+     </property>
+     <addaction name="mActionPreviewModeOff"/>
+     <addaction name="mActionPreviewModeGrayscale"/>
+     <addaction name="mActionPreviewModeMono"/>
+     <addaction name="mActionPreviewProtanope"/>
+     <addaction name="mActionPreviewDeuteranope"/>
+    </widget>
     <addaction name="mActionPan"/>
     <addaction name="mActionPanToSelected"/>
     <addaction name="mActionZoomIn"/>
@@ -105,10 +115,12 @@
     <addaction name="mActionZoomActualSize"/>
     <addaction name="separator"/>
     <addaction name="menuDecorations"/>
+    <addaction name="menuPreview_Mode"/>
     <addaction name="mActionMapTips"/>
     <addaction name="mActionNewBookmark"/>
     <addaction name="mActionShowBookmarks"/>
     <addaction name="mActionDraw"/>
+    <addaction name="separator"/>
    </widget>
    <widget class="QMenu" name="mLayerMenu">
     <property name="title">
@@ -2168,6 +2180,64 @@ Acts on currently active editable layer</string>
     <string>Save As Layer Definition File...</string>
    </property>
   </action>
+  <action name="mActionPreviewModeOff">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="checked">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Normal</string>
+   </property>
+   <property name="toolTip">
+    <string>Normal preview mode</string>
+   </property>
+  </action>
+  <action name="mActionPreviewModeGrayscale">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Simulate photocopy (grayscale)</string>
+   </property>
+   <property name="toolTip">
+    <string>Simulate Photocopy (Grayscale)</string>
+   </property>
+  </action>
+  <action name="mActionPreviewModeMono">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Simulate fax (mono)</string>
+   </property>
+   <property name="toolTip">
+    <string>Simulate Fax (Mono)</string>
+   </property>
+  </action>
+  <action name="mActionPreviewProtanope">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Simulate color blindness (Protanope)</string>
+   </property>
+   <property name="toolTip">
+    <string>Simulate Color Blindness (Protanope)</string>
+   </property>
+  </action>
+  <action name="mActionPreviewDeuteranope">
+   <property name="checkable">
+    <bool>true</bool>
+   </property>
+   <property name="text">
+    <string>Simulate color blindness (Deuteranope)</string>
+   </property>
+   <property name="toolTip">
+    <string>Simulate Color Blindness (Deuteranope)</string>
+   </property>
+  </action>
  </widget>
  <resources>
   <include location="../../images/images.qrc"/>