Add api to allow QgsBlendModeComboBox to show clipping style blend modes

qgis · Nov 24, 2021 · bb17d1c · bb17d1c
1 parent 22c16f2
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Showing 3 changed files with 115 additions and 62 deletions.
diff --git a/python/gui/auto_generated/qgsblendmodecombobox.sip.in b/python/gui/auto_generated/qgsblendmodecombobox.sip.in
@@ -27,12 +27,45 @@ Constructor for QgsBlendModeComboBox
 
     QPainter::CompositionMode blendMode();
 %Docstring
-Function to read the selected blend mode as QPainter.CompositionMode
+Returns the selected blend mode.
+
+.. seealso:: :py:func:`setBlendMode`
 %End
+
     void setBlendMode( QPainter::CompositionMode blendMode );
 %Docstring
-Function to set the selected blend mode from QPainter.CompositionMode
+Sets the selected blend mode.
+
+.. seealso:: :py:func:`blendMode`
+%End
+
+    void setShowClippingModes( bool show );
+%Docstring
+Sets whether composition modes which cause clipping are shown in the combo box.
+
+By default, these composition modes (such as QPainter.CompositionMode.CompositionMode_DestinationIn )
+are not shown in the combo box, as they can only be used with predictable results in a limited
+set of circumstances. By setting ``show`` to ``True`` these additional composition modes
+will be shown in the combo box.
+
+.. seealso:: :py:func:`showClippingModes`
+
+.. versionadded:: 3.24
+%End
+
+    bool showClippingModes() const;
+%Docstring
+Returns ``True`` if composition modes which cause clipping are shown in the combo box.
+
+By default, these composition modes (such as QPainter.CompositionMode.CompositionMode_DestinationIn )
+are not shown in the combo box, as they can only be used with predictable results in a limited
+set of circumstances.
+
+.. seealso:: :py:func:`setShowClippingModes`
+
+.. versionadded:: 3.24
 %End
+
   public slots:
 
     void updateModes();

diff --git a/src/gui/qgsblendmodecombobox.cpp b/src/gui/qgsblendmodecombobox.cpp
@@ -25,75 +25,73 @@
 #include <QSettings>
 #include <QLineEdit>
 
-QgsBlendModeComboBox::QgsBlendModeComboBox( QWidget *parent ) : QComboBox( parent )
+QgsBlendModeComboBox::QgsBlendModeComboBox( QWidget *parent )
+  : QComboBox( parent )
 {
   updateModes();
 }
 
-QStringList QgsBlendModeComboBox::blendModesList() const
-{
-  return QStringList() << tr( "Normal" )
-         << QStringLiteral( "-" )
-         << tr( "Lighten" )
-         << tr( "Screen" )
-         << tr( "Dodge" )
-         << tr( "Addition" )
-         << QStringLiteral( "-" )
-         << tr( "Darken" )
-         << tr( "Multiply" )
-         << tr( "Burn" )
-         << QStringLiteral( "-" )
-         << tr( "Overlay" )
-         << tr( "Soft light" )
-         << tr( "Hard light" )
-         << QStringLiteral( "-" )
-         << tr( "Difference" )
-         << tr( "Subtract" );
-}
-
 void QgsBlendModeComboBox::updateModes()
 {
   blockSignals( true );
   clear();
 
-  const QStringList myBlendModesList = blendModesList();
-  QStringList::const_iterator blendModeIt = myBlendModesList.constBegin();
+  // This list is designed to emulate GIMP's layer modes, where
+  // blending modes are grouped by their effect (lightening, darkening, etc)
 
-  mBlendModeToListIndex.resize( myBlendModesList.count() );
-  mListIndexToBlendMode.resize( myBlendModesList.count() );
+  addItem( tr( "Normal" ), static_cast< int >( QgsPainting::BlendMode::BlendNormal ) );
+  insertSeparator( count() );
+  addItem( tr( "Lighten" ), static_cast< int >( QgsPainting::BlendMode::BlendLighten ) );
+  addItem( tr( "Screen" ), static_cast< int >( QgsPainting::BlendMode::BlendScreen ) );
+  addItem( tr( "Dodge" ), static_cast< int >( QgsPainting::BlendMode::BlendDodge ) );
+  addItem( tr( "Addition" ), static_cast< int >( QgsPainting::BlendMode::BlendAddition ) );
+  insertSeparator( count() );
+  addItem( tr( "Darken" ), static_cast< int >( QgsPainting::BlendMode::BlendDarken ) );
+  addItem( tr( "Multiply" ), static_cast< int >( QgsPainting::BlendMode::BlendMultiply ) );
+  addItem( tr( "Burn" ), static_cast< int >( QgsPainting::BlendMode::BlendBurn ) );
+  insertSeparator( count() );
+  addItem( tr( "Overlay" ), static_cast< int >( QgsPainting::BlendMode::BlendOverlay ) );
+  addItem( tr( "Soft Light" ), static_cast< int >( QgsPainting::BlendMode::BlendSoftLight ) );
+  addItem( tr( "Hard Light" ), static_cast< int >( QgsPainting::BlendMode::BlendHardLight ) );
+  insertSeparator( count() );
+  addItem( tr( "Difference" ), static_cast< int >( QgsPainting::BlendMode::BlendDifference ) );
+  addItem( tr( "Subtract" ), static_cast< int >( QgsPainting::BlendMode::BlendSubtract ) );
 
-  // Loop through blend modes
-  int index = 0;
-  int blendModeIndex = 0;
-  for ( ; blendModeIt != myBlendModesList.constEnd(); ++blendModeIt )
+  if ( mShowClipModes )
   {
-    if ( *blendModeIt == QLatin1String( "-" ) )
-    {
-      // Add separator
-      insertSeparator( index );
-    }
-    else
-    {
-      // Not a separator, so store indexes for translation
-      // between blend modes and combo box item index
-      addItem( *blendModeIt );
-      mListIndexToBlendMode[ index ] = blendModeIndex;
-      mBlendModeToListIndex[ blendModeIndex ] = index;
-      blendModeIndex++;
-    }
-    index++;
+    insertSeparator( count() );
+    addItem( tr( "Masked By Below" ), static_cast< int >( QgsPainting::BlendMode::BlendSourceIn ) );
+    addItem( tr( "Mask Below" ), static_cast< int >( QgsPainting::BlendMode::BlendDestinationIn ) );
+    addItem( tr( "Inverse Masked By Below" ), static_cast< int >( QgsPainting::BlendMode::BlendSourceOut ) );
+    addItem( tr( "Inverse Mask Below" ), static_cast< int >( QgsPainting::BlendMode::BlendDestinationOut ) );
+    addItem( tr( "Paint Inside Below" ), static_cast< int >( QgsPainting::BlendMode::BlendSourceAtop ) );
+    addItem( tr( "Paint Below Inside" ), static_cast< int >( QgsPainting::BlendMode::BlendDestinationAtop ) );
   }
 
   blockSignals( false );
 }
 
 QPainter::CompositionMode QgsBlendModeComboBox::blendMode()
 {
-  return QgsPainting::getCompositionMode( ( QgsPainting::BlendMode ) mListIndexToBlendMode[ currentIndex()] );
+  return QgsPainting::getCompositionMode( static_cast< QgsPainting::BlendMode >( currentData().toInt() ) );
 }
 
 void QgsBlendModeComboBox::setBlendMode( QPainter::CompositionMode blendMode )
 {
-  setCurrentIndex( mBlendModeToListIndex[( int ) QgsPainting::getBlendModeEnum( blendMode )] );
+  setCurrentIndex( findData( static_cast< int >( QgsPainting::getBlendModeEnum( blendMode ) ) ) );
+}
+
+void QgsBlendModeComboBox::setShowClippingModes( bool show )
+{
+  mShowClipModes = show;
+  const QPainter::CompositionMode mode = blendMode();
+  updateModes();
+
+  setBlendMode( mode );
+}
+
+bool QgsBlendModeComboBox::showClippingModes() const
+{
+  return mShowClipModes;
 }
 
diff --git a/src/gui/qgsblendmodecombobox.h b/src/gui/qgsblendmodecombobox.h
@@ -35,24 +35,46 @@ class GUI_EXPORT QgsBlendModeComboBox : public QComboBox
     //! Constructor for QgsBlendModeComboBox
     QgsBlendModeComboBox( QWidget *parent SIP_TRANSFERTHIS = nullptr );
 
-    //! Function to read the selected blend mode as QPainter::CompositionMode
+    /**
+     * Returns the selected blend mode.
+     * \see setBlendMode()
+     */
     QPainter::CompositionMode blendMode();
-    //! Function to set the selected blend mode from QPainter::CompositionMode
+
+    /**
+     * Sets the selected blend mode.
+     * \see blendMode()
+     */
     void setBlendMode( QPainter::CompositionMode blendMode );
-  private:
 
     /**
-     * Returns a QStringList of the translated blend modes
-    * "-" is used to indicate the position of a separator in the list
-    * This list is designed to emulate GIMP's layer modes, where
-    * blending modes are grouped by their effect (lightening, darkening, etc)
-    */
-    QStringList blendModesList() const;
+     * Sets whether composition modes which cause clipping are shown in the combo box.
+     *
+     * By default, these composition modes (such as QPainter::CompositionMode::CompositionMode_DestinationIn )
+     * are not shown in the combo box, as they can only be used with predictable results in a limited
+     * set of circumstances. By setting \a show to TRUE these additional composition modes
+     * will be shown in the combo box.
+     *
+     * \see showClippingModes()
+     * \since QGIS 3.24
+     */
+    void setShowClippingModes( bool show );
+
+    /**
+     * Returns TRUE if composition modes which cause clipping are shown in the combo box.
+     *
+     * By default, these composition modes (such as QPainter::CompositionMode::CompositionMode_DestinationIn )
+     * are not shown in the combo box, as they can only be used with predictable results in a limited
+     * set of circumstances.
+     *
+     * \see setShowClippingModes()
+     * \since QGIS 3.24
+     */
+    bool showClippingModes() const;
+
+  private:
 
-    //! Used to map blend modes across to their corresponding
-    //  index within the combo box
-    std::vector<int> mBlendModeToListIndex;
-    std::vector<int> mListIndexToBlendMode;
+    bool mShowClipModes = false;
 
   public slots: