Merge pull request #1318 from 3nids/fieldexpressionmodel

field expression widget (with expression capability added to QgsFieldModel)

python/gui/gui.sip

@@ -29,6 +29,7 @@
 %Include qgsexpressionbuilderwidget.sip
 %Include qgsexpressionhighlighter.sip
 %Include qgsfieldcombobox.sip
+%Include qgsfieldexpressionwidget.sip
 %Include qgsfieldmodel.sip
 %Include qgsfieldvalidator.sip
 %Include qgsfiledropedit.sip

python/gui/qgsfieldcombobox.sip

@@ -1,5 +1,8 @@
 /**
  * @brief The QgsFieldComboBox is a combo box which displays the list of fields of a given layer.
+ * It might be combined with a QgsMapLayerComboBox to automatically update fields according to a chosen layer.
+ * If expression must be used, QgsFieldExpressionWidget shall be used instead.
+ * @see QgsMapLayerComboBox
  * @note added in 2.3
  */
 class QgsFieldComboBox : QComboBox
@@ -16,25 +19,23 @@ class QgsFieldComboBox : QComboBox
      */
     explicit QgsFieldComboBox( QWidget *parent /TransferThis/ = 0 );
 
-    /**
-     * @brief currentField returns the currently selected field
-     */
+    //! return the currently selected field
     QString currentField();
 
+    //! Returns the currently used layer
+    QgsVectorLayer* layer();
+
   signals:
-    /**
-     * @brief fieldChanged the signal is emitted when the currently selected field changes
-     */
+    //! the signal is emitted when the currently selected field changes
     void fieldChanged( QString fieldName );
 
   public slots:
-    /**
-     * @brief setLayer sets the layer of which the fields are listed
-     */
+    //! set the layer of which the fields are listed
+    void setLayer( QgsVectorLayer* layer );
+
+    //! convenience slot to connect QgsMapLayerComboBox layer signal
     void setLayer( QgsMapLayer* layer );
-    /**
-     * @brief setField sets the currently selected field
-     */
-    void setField( QString fieldName );
 
+    //! setField sets the currently selected field
+    void setField( QString fieldName );
 };

python/gui/qgsfieldexpressionwidget.sip

@@ -0,0 +1,45 @@
+
+class QgsFieldExpressionWidget : QWidget
+{
+%TypeHeaderCode
+#include "qgsfieldexpressionwidget.h"
+%End
+
+  public:
+    /**
+     * @brief QgsFieldExpressionWidget creates a widget with a combo box to display the fields and expression and a button to open the expression dialog
+     */
+    explicit QgsFieldExpressionWidget( QWidget *parent /TransferThis/ = 0 );
+
+    //! define the title used in the expression dialog
+    void setExpressionDialogTitle( QString title );
+
+    //! set the geometry calculator used in the expression dialog
+    void setGeomCalculator( const QgsDistanceArea &da );
+
+    /**
+     * @brief currentField returns the currently selected field or expression if allowed
+     * @param isExpression determines if the string returned is the name of a field or an expression
+     */
+    QString currentField( bool *isExpression = 0 );
+
+    //! Returns the currently used layer
+    QgsVectorLayer* layer();
+
+  signals:
+     //! the signal is emitted when the currently selected field changes
+     void fieldChanged( QString fieldName );
+
+    //! fieldChanged signal with indication of the validity of the expression
+    void fieldChanged( QString fieldName, bool isValid );
+
+  public slots:
+    //! set the layer used to display the fields and expression
+    void setLayer( QgsVectorLayer* layer );
+
+    //! convenience slot to connect QgsMapLayerComboBox layer signal
+    void setLayer( QgsMapLayer* layer );
+
+    //! sets the current field or expression in the widget
+    void setField( QString fieldName );
+};

python/gui/qgsfieldmodel.sip

@@ -1,41 +1,62 @@
 
 /**
  * @brief The QgsFieldModel class is a model to display the list of fields of a layer in widgets.
+ * If allowed, expressions might be added to the end of the model.
  * It can be associated with a QgsMapLayerModel to dynamically display a layer and its fields.
  * @note added in 2.3
  */
-
 class QgsFieldModel : QAbstractItemModel
 {
 %TypeHeaderCode
 #include "qgsfieldmodel.h"
 %End
 
   public:
-    static const int FieldNameRole;
-    static const int FieldIndexRole;
+    enum FieldRoles {
+      /* SIP does not accept any arithmetic" */
+      FieldNameRole = 33,  /* return field name if index corresponds to a field */
+      FieldIndexRole = 34, /* return field index if index corresponds to a field */
+      ExpressionRole = 35, /* return field name or expression */
+      IsExpressionRole = 36, /* return if index corresponds to an expression */
+      ExpressionValidityRole = 37 /* return if expression is valid or not */
+    };
 
     /**
      * @brief QgsFieldModel creates a model to display the fields of a given layer
      */
     explicit QgsFieldModel( QObject *parent /TransferThis/ = 0 );
 
-    /**
-     * @brief indexFromName returns the index corresponding to a given fieldName
-     */
+    //! return the index corresponding to a given fieldName
     QModelIndex indexFromName( QString fieldName );
+
+    //! returns the currently used layer
+    void setAllowExpression( bool allowExpression );
+    bool allowExpression();
 
-  public slots:
     /**
-     * @brief setLayer sets the layer of whch fields are displayed
+     * @brief setExpression sets a single expression to be added after the fields at the end of the model
+     * @return the model index of the newly added expression
      */
-    void setLayer( QgsMapLayer *layer );
+    QModelIndex setExpression( QString expression );
+
+    //! remove expressions from the model
+    void removeExpression();
+
+    //! returns the currently used layer
+    QgsVectorLayer* layer();
 
+  public slots:
+    //! set the layer of whch fields are displayed
+    void setLayer( QgsVectorLayer *layer );
+
+  protected slots:
+    virtual void updateModel();
+
     // QAbstractItemModel interface
   public:
     QModelIndex index( int row, int column, const QModelIndex &parent = QModelIndex() ) const;
     QModelIndex parent( const QModelIndex &child ) const;
-    int rowCount( const QModelIndex &parent ) const;
+    int rowCount( const QModelIndex &parent = QModelIndex() ) const;
     int columnCount( const QModelIndex &parent ) const;
     QVariant data( const QModelIndex &index, int role ) const;
 

python/gui/symbology-ng/qgscategorizedsymbolrendererv2widget.sip

@@ -14,13 +14,12 @@ class QgsCategorizedSymbolRendererV2Widget : QgsRendererV2Widget
 
   public slots:
     void changeCategorizedSymbol();
-    void categoryColumnChanged();
+    void categoryColumnChanged( QString field );
     void categoriesDoubleClicked( const QModelIndex & idx );
     void addCategory();
     void addCategories();
     void deleteCategories();
     void deleteAllCategories();
-    void setExpression();
 
     void rotationFieldChanged( QString fldName );
     void sizeScaleFieldChanged( QString fldName );
@@ -39,9 +38,6 @@ class QgsCategorizedSymbolRendererV2Widget : QgsRendererV2Widget
     // Called by virtual refreshSymbolView()
     void populateCategories();
 
-    //! populate column combo
-    void populateColumns();
-
     //! return row index for the currently selected category (-1 if on no selection)
     int currentCategoryRow();
 

python/gui/symbology-ng/qgsgraduatedsymbolrendererv2widget.sip

@@ -13,8 +13,7 @@ class QgsGraduatedSymbolRendererV2Widget : QgsRendererV2Widget
 
   public slots:
     void changeGraduatedSymbol();
-    void graduatedColumnChanged();
-    void setExpression();
+    void graduatedColumnChanged( QString field );
     void classifyGraduated();
     void reapplyColorRamp();
     void rangesDoubleClicked( const QModelIndex & idx );
@@ -45,9 +44,6 @@ class QgsGraduatedSymbolRendererV2Widget : QgsRendererV2Widget
     QList<int> selectedClasses();
     QgsRangeList selectedRanges();
 
-    //! populate column combos in categorized and graduated page
-    void populateColumns();
-
     void changeRangeSymbol( int rangeIdx );
     void changeRange( int rangeIdx );
 

src/app/qgslabelinggui.cpp

@@ -58,8 +58,7 @@ QgsLabelingGui::QgsLabelingGui( QgsVectorLayer* layer, QgsMapCanvas* mapCanvas,
   mPreviewSize = 24;
 
   // main layer label-enabling connections
-  connect( chkEnableLabeling, SIGNAL( toggled( bool ) ), cboFieldName, SLOT( setEnabled( bool ) ) );
-  connect( chkEnableLabeling, SIGNAL( toggled( bool ) ), btnExpression, SLOT( setEnabled( bool ) ) );
+  connect( chkEnableLabeling, SIGNAL( toggled( bool ) ), mFieldExpressionWidget, SLOT( setEnabled( bool ) ) );
   connect( chkEnableLabeling, SIGNAL( toggled( bool ) ), mLabelingFrame, SLOT( setEnabled( bool ) ) );
 
   // connections for groupboxes with separate activation checkboxes (that need to honor data defined setting)
@@ -96,7 +95,6 @@ QgsLabelingGui::QgsLabelingGui( QgsVectorLayer* layer, QgsMapCanvas* mapCanvas,
   connect( mLimitLabelChkBox, SIGNAL( toggled( bool ) ), mLimitLabelSpinBox, SLOT( setEnabled( bool ) ) );
 
   connect( btnEngineSettings, SIGNAL( clicked() ), this, SLOT( showEngineConfigDialog() ) );
-  connect( btnExpression, SIGNAL( clicked() ), this, SLOT( showExpressionDialog() ) );
 
   // set placement methods page based on geometry type
   switch ( layer->geometryType() )
@@ -121,7 +119,14 @@ QgsLabelingGui::QgsLabelingGui( QgsVectorLayer* layer, QgsMapCanvas* mapCanvas,
   mDirectSymbolsFrame->setVisible( layer->geometryType() == QGis::Line );
   mMinSizeFrame->setVisible( layer->geometryType() != QGis::Point );
 
-  populateFieldNames(); // this is just for label text combo box
+  // field combo and expression button
+  mFieldExpressionWidget->setLayer( mLayer );
+  QgsDistanceArea myDa;
+  myDa.setSourceCrs( mLayer->crs().srsid() );
+  myDa.setEllipsoidalMode( QgisApp::instance()->mapCanvas()->mapSettings().hasCrsTransformEnabled() );
+  myDa.setEllipsoid( QgsProject::instance()->readEntry( "Measure", "/Ellipsoid", GEO_NONE ) );
+  mFieldExpressionWidget->setGeomCalculator( myDa );
+
   populateFontCapitalsComboBox();
 
   // set up quadrant offset button group
@@ -234,15 +239,11 @@ void QgsLabelingGui::init()
 
   // enable/disable main options based upon whether layer is being labeled
   chkEnableLabeling->setChecked( lyr.enabled );
-  cboFieldName->setEnabled( chkEnableLabeling->isChecked() );
-  btnExpression->setEnabled( chkEnableLabeling->isChecked() );
+  mFieldExpressionWidget->setEnabled( chkEnableLabeling->isChecked() );
   mLabelingFrame->setEnabled( chkEnableLabeling->isChecked() );
 
-  // add the current expression to the bottom of the list
-  if ( lyr.isExpression && !lyr.fieldName.isEmpty() )
-    cboFieldName->addItem( lyr.fieldName );
-
-  cboFieldName->setCurrentIndex( cboFieldName->findText( lyr.fieldName ) );
+  // set the current field or add the current expression to the bottom of the list
+  mFieldExpressionWidget->setField( lyr.fieldName );
 
   // populate placement options
   int distUnitIndex = lyr.distInMapUnits ? 1 : 0;
@@ -509,10 +510,9 @@ QgsPalLayerSettings QgsLabelingGui::layerSettings()
 
   lyr.enabled = chkEnableLabeling->isChecked();
 
-  lyr.fieldName = cboFieldName->currentText();
-  // Check if we are an expression. Also treats expressions with just a column name as non expressions,
-  // this saves time later so we don't have to parse the expression tree.
-  lyr.isExpression = mLayer->fieldNameIndex( lyr.fieldName ) == -1 && !lyr.fieldName.isEmpty();
+  bool isExpression;
+  lyr.fieldName = mFieldExpressionWidget->currentField( &isExpression );
+  lyr.isExpression = isExpression;
 
   lyr.dist = 0;
   lyr.placementFlags = 0;
@@ -775,15 +775,6 @@ void QgsLabelingGui::setDataDefinedProperty( const QgsDataDefinedButton* ddBtn,
   lyr.setDataDefinedProperty( p, map.value( "active" ).toInt(), map.value( "useexpr" ).toInt(), map.value( "expression" ), map.value( "field" ) );
 }
 
-void QgsLabelingGui::populateFieldNames()
-{
-  const QgsFields& fields = mLayer->pendingFields();
-  for ( int idx = 0; idx < fields.count(); ++idx )
-  {
-    cboFieldName->addItem( fields[idx].name() );
-  }
-}
-
 void QgsLabelingGui::populateDataDefinedButtons( QgsPalLayerSettings& s )
 {
   // don't register enable/disable siblings, since visual feedback from data defined buttons should be enough,
@@ -1175,30 +1166,6 @@ void QgsLabelingGui::showEngineConfigDialog()
   dlg.exec();
 }
 
-void QgsLabelingGui::showExpressionDialog()
-{
-  QgsExpressionBuilderDialog dlg( mLayer, cboFieldName->currentText() , this );
-  dlg.setWindowTitle( tr( "Expression based label" ) );
-
-  QgsDistanceArea myDa;
-  myDa.setSourceCrs( mLayer->crs().srsid() );
-  myDa.setEllipsoidalMode( QgisApp::instance()->mapCanvas()->mapSettings().hasCrsTransformEnabled() );
-  myDa.setEllipsoid( QgsProject::instance()->readEntry( "Measure", "/Ellipsoid", GEO_NONE ) );
-  dlg.setGeomCalculator( myDa );
-
-  if ( dlg.exec() == QDialog::Accepted )
-  {
-    QString expression =  dlg.expressionText();
-    //Only add the expression if the user has entered some text.
-    if ( !expression.isEmpty() )
-    {
-      cboFieldName->addItem( expression );
-      cboFieldName->setCurrentIndex( cboFieldName->count() - 1 );
-    }
-  }
-  activateWindow(); // set focus back parent
-}
-
 void QgsLabelingGui::syncDefinedCheckboxFrame( QgsDataDefinedButton* ddBtn, QCheckBox* chkBx, QFrame* f )
 {
   if ( ddBtn->isActive() && !chkBx->isChecked() )

src/app/qgslabelinggui.h

@@ -45,7 +45,6 @@ class APP_EXPORT QgsLabelingGui : public QWidget, private Ui::QgsLabelingGuiBase
     void apply();
     void changeTextColor( const QColor &color );
     void showEngineConfigDialog();
-    void showExpressionDialog();
     void changeBufferColor( const QColor &color );
 
     void updateUi();

src/gui/CMakeLists.txt

@@ -89,6 +89,7 @@ qgsexpressionselectiondialog.cpp
 qgsextentgroupbox.cpp
 qgsfeatureselectiondlg.cpp
 qgsfieldcombobox.cpp
+qgsfieldexpressionwidget.cpp
 qgsfieldmodel.cpp
 qgsfieldvalidator.cpp
 qgsfiledropedit.cpp
@@ -233,6 +234,7 @@ qgsexpressionselectiondialog.h
 qgsextentgroupbox.h
 qgsfeatureselectiondlg.h
 qgsfieldcombobox.h
+qgsfieldexpressionwidget.h
 qgsfieldmodel.h
 qgsfieldvalidator.h
 qgsfilterlineedit.h
@@ -303,6 +305,7 @@ qgsexpressionhighlighter.h
 qgsexpressionselectiondialog.h
 qgsfeatureselectiondlg.h
 qgsfieldcombobox.h
+qgsfieldexpressionwidget.h
 qgsfieldmodel.h
 qgsfieldvalidator.h
 qgsfiledropedit.h

src/gui/qgsfieldcombobox.cpp

@@ -27,10 +27,24 @@ QgsFieldComboBox::QgsFieldComboBox( QWidget *parent ) :
 }
 
 void QgsFieldComboBox::setLayer( QgsMapLayer *layer )
+{
+  QgsVectorLayer* vl = dynamic_cast<QgsVectorLayer*>( layer );
+  if ( vl )
+  {
+    setLayer( vl );
+  }
+}
+
+void QgsFieldComboBox::setLayer( QgsVectorLayer *layer )
 {
   mFieldModel->setLayer( layer );
 }
 
+QgsVectorLayer *QgsFieldComboBox::layer()
+{
+  return mFieldModel->layer();
+}
+
 void QgsFieldComboBox::setField( QString fieldName )
 {
   QModelIndex idx = mFieldModel->indexFromName( fieldName );