[FEATURE] Transparency control for composer items

src/app/composer/qgscomposeritemwidget.cpp

@@ -355,6 +355,7 @@ void QgsComposerItemWidget::setValuesForGuiElements()
   mItemIdLineEdit->blockSignals( true );
   mItemUuidLineEdit->blockSignals( true );
   mBlendModeCombo->blockSignals( true );
+  mTransparencySlider->blockSignals( true );
 //  mTransparencySpinBox->blockSignals( true );
 
   mBackgroundColorButton->setColor( mItem->brush().color() );
@@ -373,6 +374,7 @@ void QgsComposerItemWidget::setValuesForGuiElements()
   mFrameGroupBox->setChecked( mItem->hasFrame() );
   mBackgroundGroupBox->setChecked( mItem->hasBackground() );
   mBlendModeCombo->setBlendMode( mItem->blendMode() );
+  mTransparencySlider->setValue( mItem->transparency() );
 
 //  mTransparencySlider->blockSignals( false );
   mOutlineWidthSpinBox->blockSignals( false );
@@ -381,6 +383,7 @@ void QgsComposerItemWidget::setValuesForGuiElements()
   mItemIdLineEdit->blockSignals( false );
   mItemUuidLineEdit->blockSignals( false );
   mBlendModeCombo->blockSignals( false );
+  mTransparencySlider->blockSignals( false );
 //  mTransparencySpinBox->blockSignals( false );
 }
 
@@ -393,6 +396,14 @@ void QgsComposerItemWidget::on_mBlendModeCombo_currentIndexChanged( int index )
   }
 }
 
+void QgsComposerItemWidget::on_mTransparencySlider_valueChanged( int value )
+{
+  if ( mItem )
+  {
+    mItem->setTransparency( value );
+  }
+}
+
 void QgsComposerItemWidget::on_mItemIdLineEdit_editingFinished()
 {
   if ( mItem )

src/app/composer/qgscomposeritemwidget.h

@@ -71,6 +71,7 @@ class QgsComposerItemWidget: public QWidget, private Ui::QgsComposerItemWidgetBa
     void on_mLowerRightCheckBox_stateChanged( int state ) { Q_UNUSED( state ); changeItemPosition(); }
 
     void on_mBlendModeCombo_currentIndexChanged( int index );
+    void on_mTransparencySlider_valueChanged( int value );
 
     void setValuesForGuiElements();
     void setValuesForGuiPositionElements();

src/core/composer/qgscomposeritem.cpp

@@ -55,6 +55,7 @@ QgsComposerItem::QgsComposerItem( QgsComposition* composition, bool manageZValue
     , mLastValidViewScaleFactor( -1 )
     , mRotation( 0 )
     , mBlendMode( QgsMapRenderer::BlendNormal )
+    , mTransparency( 0 )
     , mLastUsedPositionMode( UpperLeft )
     , mId( "" )
     , mUuid( QUuid::createUuid().toString() )
@@ -75,6 +76,7 @@ QgsComposerItem::QgsComposerItem( qreal x, qreal y, qreal width, qreal height, Q
     , mLastValidViewScaleFactor( -1 )
     , mRotation( 0 )
     , mBlendMode( QgsMapRenderer::BlendNormal )
+    , mTransparency( 0 )
     , mLastUsedPositionMode( UpperLeft )
     , mId( "" )
     , mUuid( QUuid::createUuid().toString() )
@@ -205,6 +207,9 @@ bool QgsComposerItem::_writeXML( QDomElement& itemElem, QDomDocument& doc ) cons
   //blend mode
   composerItemElem.setAttribute( "blendMode", QString::number( mBlendMode ) );
 
+  //transparency
+  composerItemElem.setAttribute( "transparency", QString::number( mTransparency ) );
+
   itemElem.appendChild( composerItemElem );
 
   return true;
@@ -328,6 +333,9 @@ bool QgsComposerItem::_readXML( const QDomElement& itemElem, const QDomDocument&
   //blend mode
   setBlendMode(( QgsMapRenderer::BlendMode ) itemElem.attribute( "blendMode" , "0" ).toInt() );
 
+  //transparency
+  setTransparency( itemElem.attribute( "transparency" , "0" ).toInt() );
+
   return true;
 }
 
@@ -883,6 +891,12 @@ void QgsComposerItem::setBlendMode( QgsMapRenderer::BlendMode blendMode )
   mEffect->setCompositionMode( QgsMapRenderer::getCompositionMode( mBlendMode ) );
 }
 
+void QgsComposerItem::setTransparency( int transparency )
+{
+  mTransparency = transparency;
+  // Set the QGraphicItem's opacity
+  setOpacity( 1. - ( transparency / 100. ) );
+}
 
 void QgsComposerItem::hoverMoveEvent( QGraphicsSceneHoverEvent * event )
 {

src/core/composer/qgscomposeritem.h

@@ -203,6 +203,11 @@ class CORE_EXPORT QgsComposerItem: public QObject, public QGraphicsRectItem
     /** Sets the item's composition blending mode*/
     void setBlendMode( QgsMapRenderer::BlendMode blendMode );
 
+    /** Returns the item's transparency */
+    int transparency() const {return mTransparency;}
+    /** Sets the item's transparency */
+    void setTransparency( int transparency );
+
     /**Composite operations for item groups do nothing per default*/
     virtual void addItem( QgsComposerItem* item ) { Q_UNUSED( item ); }
     virtual void removeItems() {}
@@ -320,6 +325,9 @@ class CORE_EXPORT QgsComposerItem: public QObject, public QGraphicsRectItem
 
     QgsComposerEffect *mEffect;
 
+    /**Item transparency*/
+    int mTransparency;
+
     /**The item's position mode
     @note: this member was added in version 2.0*/
     ItemPositionMode mLastUsedPositionMode;

src/ui/qgscomposeritemwidgetbase.ui

@@ -356,6 +356,23 @@
       <item row="0" column="1">
        <widget class="QgsBlendModeComboBox" name="mBlendModeCombo"/>
       </item>
+      <item row="1" column="0">
+       <widget class="QLabel" name="labelTransparency">
+        <property name="text">
+         <string>Transparency</string>
+        </property>
+       </widget>
+      </item>
+      <item row="1" column="1">
+       <widget class="QSlider" name="mTransparencySlider">
+        <property name="maximum">
+         <number>100</number>
+        </property>
+        <property name="orientation">
+         <enum>Qt::Horizontal</enum>
+        </property>
+       </widget>
+      </item>
      </layout>
     </widget>
    </item>