[composer] Initial framework for data defined properties in compositions and composer items. Funded by Canton of Neuchâtel, Switzerland

Author: nyalldawson

python/core/composer/qgscomposeritem.sip

@@ -133,6 +133,36 @@ class QgsComposerItem : QObject, QGraphicsRectItem
       LowerRight
     };
 
+    /** Data defined properties for different item types
+     */
+    enum DataDefinedProperty
+    {
+      NoProperty = 0, /*< no property */
+      AllProperties, /*< all properties for item */
+      //composer page properties
+      PresetPaperSize, /*< preset paper size for composition */
+      PaperWidth, /*< paper width */
+      PaperHeight, /*< paper height */
+      NumPages, /*< number of pages in composition */
+      PaperOrientation, /*< paper orientation */
+      //general composer item properties
+      PageNumber, /*< page number for item placement */
+      PositionX, /*< x position on page */
+      PositionY, /*< y position on page */
+      ItemWidth, /*< width of item */
+      ItemHeight, /*< height of item */
+      ItemRotation, /*< rotation of item */
+      Transparency, /*< item transparency */
+      BlendMode, /*< item blend mode */
+      //composer map
+      MapRotation, /*< map rotation */
+      MapScale, /*< map scale */
+      MapXMin, /*< map extent x minimum */
+      MapYMin, /*< map extent y minimum */
+      MapXMax, /*< map extent x maximum */
+      MapYMax /*< map extent y maximum */
+    };
+
     /**Constructor
      @param composition parent composition
      @param manageZValue true if the z-Value of this object should be managed by mComposition*/
@@ -481,22 +511,47 @@ class QgsComposerItem : QObject, QGraphicsRectItem
     */
     void setCurrentExportLayer( int layerIdx = -1 );
 
+    /**Returns a reference to the data defined settings for one of the item's data defined properties.
+     * @param property data defined property to return
+     * @note this method was added in version 2.5
+    */
+    QgsDataDefined* dataDefinedProperty( DataDefinedProperty property );
+
+    /**Sets parameters for a data defined property for the item
+     * @param property data defined property to set
+     * @param active true if data defined property is active, false if it is disabled
+     * @param useExpression true if the expression should be used
+     * @param expression expression for data defined property
+     * @field field name if the data defined property should take its value from a field
+     * @note this method was added in version 2.5
+    */
+    void setDataDefinedProperty( DataDefinedProperty property, bool active, bool useExpression, const QString &expression, const QString &field );
+
   public slots:
     /**Sets the item rotation
      * @deprecated Use setItemRotation( double rotation ) instead
      */
     virtual void setRotation( double r );
 
     /**Sets the item rotation
-      @param r item rotation in degrees
-      @param adjustPosition set to true if item should be shifted so that rotation occurs
-       around item center. If false, rotation occurs around item origin
-      @note this method was added in version 2.1
+     * @param r item rotation in degrees
+     * @param adjustPosition set to true if item should be shifted so that rotation occurs
+     * around item center. If false, rotation occurs around item origin
+     * @note this method was added in version 2.1
     */
     virtual void setItemRotation( double r, bool adjustPosition = false );
 
     void repaint();
 
+    /**Refreshes a data defined property for the item by reevaluating the property's value
+     * and redrawing the item with this new value.
+     * @param property data defined property to refresh. If property is set to
+     * QgsComposerItem::AllProperties then all data defined properties for the item will be
+     * refreshed.
+     * @note this method was added in version 2.5
+    */
+    virtual void refreshDataDefinedProperty( DataDefinedProperty property = AllProperties );
+
   protected:
 
     //event handlers
@@ -582,6 +637,14 @@ class QgsComposerItem : QObject, QGraphicsRectItem
     void deleteVAlignSnapItem();
     void deleteAlignItems();
 
+    /**Evaluate a data defined property and return the calculated value
+     * @returns true if data defined property could be successfully evaluated
+     * @param property data defined property to evaluate
+     * @param expressionValue QVariant for storing the evaluated value
+     * @note this method was added in version 2.5
+    */
+    bool dataDefinedEvaluate( QgsComposerItem::DataDefinedProperty property, QVariant &expressionValue );
+
   signals:
     /**Is emitted on item rotation change*/
     void itemRotationChanged( double newRotation );

python/core/composer/qgscomposition.sip

@@ -444,6 +444,22 @@ class QgsComposition : QGraphicsScene
      @note added in version 2.4*/
     QList< QgsPaperItem* > pages();
 
+    /**Returns a reference to the data defined settings for one of the composition's data defined properties.
+     * @param property data defined property to return
+     * @note this method was added in version 2.5
+    */
+    QgsDataDefined* dataDefinedProperty( QgsComposerItem::DataDefinedProperty property );
+
+    /**Sets parameters for a data defined property for the composition
+     * @param property data defined property to set
+     * @param active true if data defined property is active, false if it is disabled
+     * @param useExpression true if the expression should be used
+     * @param expression expression for data defined property
+     * @field field name if the data defined property should take its value from a field
+     * @note this method was added in version 2.5
+    */
+    void setDataDefinedProperty( QgsComposerItem::DataDefinedProperty property, bool active, bool useExpression, const QString &expression, const QString &field );
+
   public slots:
     /**Casts object to the proper subclass type and calls corresponding itemAdded signal*/
     void sendItemAddedSignal( QgsComposerItem* item );
@@ -463,6 +479,15 @@ class QgsComposition : QGraphicsScene
      * @note added in version 2.3*/
     void setSelectedItem( QgsComposerItem* item );
 
+    /**Refreshes a data defined property for the composition by reevaluating the property's value
+     * and redrawing the composition with this new value.
+     * @param property data defined property to refresh. If property is set to
+     * QgsComposerItem::AllProperties then all data defined properties for the composition will be
+     * refreshed.
+     * @note this method was added in version 2.5
+    */
+    void refreshDataDefinedProperty( QgsComposerItem::DataDefinedProperty property = QgsComposerItem::AllProperties );
+
   protected:
     void init();
 

src/app/composer/qgscomposeritemwidget.cpp

@@ -18,8 +18,10 @@
 #include "qgscomposeritemwidget.h"
 #include "qgscomposeritem.h"
 #include "qgscomposermap.h"
+#include "qgsatlascomposition.h"
 #include "qgscomposition.h"
 #include "qgspoint.h"
+#include "qgsdatadefinedbutton.h"
 #include <QColorDialog>
 #include <QPen>
 
@@ -36,6 +38,44 @@ QgsComposerItemBaseWidget::~QgsComposerItemBaseWidget()
 
 }
 
+void QgsComposerItemBaseWidget::updateDataDefinedProperty()
+{
+  //match data defined button to item's data defined property
+  QgsDataDefinedButton* ddButton = dynamic_cast<QgsDataDefinedButton*>( sender() );
+  if ( !ddButton )
+  {
+    return;
+  }
+  QgsComposerItem::DataDefinedProperty property = ddPropertyForWidget( ddButton );
+  if ( property == QgsComposerItem::NoProperty )
+  {
+    return;
+  }
+
+  //set the data defined property and refresh the item
+  setDataDefinedProperty( ddButton, property );
+  mItem->refreshDataDefinedProperty( property );
+}
+
+void QgsComposerItemBaseWidget::setDataDefinedProperty( const QgsDataDefinedButton *ddBtn, QgsComposerItem::DataDefinedProperty p )
+{
+  if ( !mItem )
+  {
+    return;
+  }
+
+  const QMap< QString, QString >& map = ddBtn->definedProperty();
+  mItem->setDataDefinedProperty( p, map.value( "active" ).toInt(), map.value( "useexpr" ).toInt(), map.value( "expression" ), map.value( "field" ) );
+}
+
+QgsComposerItem::DataDefinedProperty QgsComposerItemBaseWidget::ddPropertyForWidget( QgsDataDefinedButton *widget )
+{
+  Q_UNUSED( widget );
+
+  //base implementation, return no property
+  return QgsComposerItem::NoProperty;
+}
+
 QgsAtlasComposition* QgsComposerItemBaseWidget::atlasComposition() const
 {
   if ( !mItem )
@@ -98,6 +138,17 @@ QgsComposerItemWidget::QgsComposerItemWidget( QWidget* parent, QgsComposerItem*
 
   connect( mTransparencySlider, SIGNAL( valueChanged( int ) ), mTransparencySpnBx, SLOT( setValue( int ) ) );
   connect( mTransparencySpnBx, SIGNAL( valueChanged( int ) ), mTransparencySlider, SLOT( setValue( int ) ) );
+
+  //connect atlas signals to data defined buttons
+  QgsAtlasComposition* atlas = atlasComposition();
+  if ( atlas )
+  {
+    //repopulate data defined buttons if atlas layer changes
+    connect( atlas, SIGNAL( coverageLayerChanged( QgsVectorLayer* ) ),
+             this, SLOT( populateDataDefinedButtons() ) );
+    connect( atlas, SIGNAL( toggled( bool ) ), this, SLOT( populateDataDefinedButtons() ) );
+  }
+
 }
 
 QgsComposerItemWidget::QgsComposerItemWidget(): QgsComposerItemBaseWidget( 0, 0 )
@@ -449,6 +500,20 @@ void QgsComposerItemWidget::setValuesForGuiNonPositionElements()
   mItemRotationSpinBox->blockSignals( false );
 }
 
+void QgsComposerItemWidget::populateDataDefinedButtons()
+{
+  //QgsVectorLayer* vl = atlasCoverageLayer();
+
+  //block signals from data defined buttons
+
+  //initialise buttons to use atlas coverage layer
+
+  //initial state of controls - disable related controls when dd buttons are active
+
+  //unblock signals from data defined buttons
+
+}
+
 void QgsComposerItemWidget::setValuesForGuiElements()
 {
   if ( !mItem )
@@ -463,6 +528,7 @@ void QgsComposerItemWidget::setValuesForGuiElements()
 
   setValuesForGuiPositionElements();
   setValuesForGuiNonPositionElements();
+  populateDataDefinedButtons();
 }
 
 void QgsComposerItemWidget::on_mBlendModeCombo_currentIndexChanged( int index )

src/app/composer/qgscomposeritemwidget.h

@@ -23,6 +23,7 @@
 
 class QgsComposerItem;
 class QgsAtlasComposition;
+class QgsDataDefinedButton;
 
 /**A base class for property widgets for composer items. All composer item widgets should inherit from
  * this base class.
@@ -34,7 +35,17 @@ class QgsComposerItemBaseWidget: public QWidget
     QgsComposerItemBaseWidget( QWidget* parent, QgsComposerItem* item );
     ~QgsComposerItemBaseWidget();
 
+  protected slots:
+    /**Must be called when a data defined button changes*/
+    void updateDataDefinedProperty();
+
   protected:
+    /**Sets a data defined property for the item from its current data defined button settings*/
+    void setDataDefinedProperty( const QgsDataDefinedButton *ddBtn, QgsComposerItem::DataDefinedProperty p );
+
+    /**Returns the data defined property corresponding to a data defined button widget*/
+    virtual QgsComposerItem::DataDefinedProperty ddPropertyForWidget( QgsDataDefinedButton* widget );
+
     /**Returns the current atlas coverage layer (if set)*/
     QgsVectorLayer* atlasCoverageLayer() const;
 
@@ -108,6 +119,10 @@ class QgsComposerItemWidget: public QgsComposerItemBaseWidget, private Ui::QgsCo
     //sets the values for all non-position related elements
     void setValuesForGuiNonPositionElements();
 
+  protected slots:
+    /**Initializes data defined buttons to current atlas coverage layer*/
+    void populateDataDefinedButtons();
+
   private:
     QgsComposerItemWidget();
 //    void changeItemTransparency( int value );