Allow the use of expressions inside a composer label

src/app/composer/qgscomposer.cpp

@@ -650,6 +650,7 @@ void QgsComposer::on_mActionExportAsPDF_triggered()
 
       if ( progress.wasCanceled() )
       {
+	atlasRender.end();
 	break;
       }
       try
@@ -717,6 +718,7 @@ void QgsComposer::on_mActionPrint_triggered()
 
       if ( progress.wasCanceled() )
       {
+	atlasRender.end();
 	break;
       }
       try
@@ -893,6 +895,7 @@ void QgsComposer::on_mActionExportAsImage_triggered()
       
       if ( progress.wasCanceled() )
       {
+	atlasRender.end();
 	break;
       }
       try

src/app/composer/qgscomposerlabelwidget.cpp

@@ -18,6 +18,8 @@
 #include "qgscomposerlabelwidget.h"
 #include "qgscomposerlabel.h"
 #include "qgscomposeritemwidget.h"
+#include "qgsexpressionbuilderdialog.h"
+
 #include <QColorDialog>
 #include <QFontDialog>
 #include <QWidget>
@@ -98,6 +100,33 @@ void QgsComposerLabelWidget::on_mFontColorButton_clicked()
   mComposerLabel->endCommand();
 }
 
+void QgsComposerLabelWidget::on_mInsertExpressionButton_clicked()
+{
+  if ( !mComposerLabel)
+  {
+    return;
+  }
+
+  QString selText = mTextEdit->textCursor().selectedText();
+
+  // edit the selected expression if there's one
+  if ( selText.startsWith( "[%" ) && selText.endsWith( "%]" ) )
+    selText = selText.mid( 2, selText.size() - 4 );
+
+  QgsExpressionBuilderDialog exprDlg( /* layer = */ 0, selText, this );
+  exprDlg.setWindowTitle( tr( "Insert expression" ) );
+  if ( exprDlg.exec() == QDialog::Accepted )
+  {
+    QString expression =  exprDlg.expressionText();
+    if ( !expression.isEmpty() )
+    {
+      mComposerLabel->beginCommand( tr( "Insert expression" ) );
+      mTextEdit->insertPlainText( "[%" + expression + "%]" );
+      mComposerLabel->endCommand();
+    }
+  }
+}
+
 void QgsComposerLabelWidget::on_mCenterRadioButton_clicked()
 {
   if ( mComposerLabel )

src/app/composer/qgscomposerlabelwidget.h

@@ -34,6 +34,7 @@ class QgsComposerLabelWidget: public QWidget, private Ui::QgsComposerLabelWidget
   public slots:
     void on_mTextEdit_textChanged();
     void on_mFontButton_clicked();
+    void on_mInsertExpressionButton_clicked();
     void on_mMarginDoubleSpinBox_valueChanged( double d );
     void on_mFontColorButton_clicked();
     void on_mCenterRadioButton_clicked();

src/core/composer/qgscomposerlabel.cpp

@@ -16,12 +16,15 @@
  ***************************************************************************/
 
 #include "qgscomposerlabel.h"
+#include "qgsexpression.h"
 #include <QDate>
 #include <QDomElement>
 #include <QPainter>
 
-QgsComposerLabel::QgsComposerLabel( QgsComposition *composition ): QgsComposerItem( composition ), mMargin( 1.0 ), mFontColor( QColor( 0, 0, 0 ) ),
+QgsComposerLabel::QgsComposerLabel( QgsComposition *composition ):
-    mHAlignment( Qt::AlignLeft ), mVAlignment( Qt::AlignTop )
+  QgsComposerItem( composition ), mMargin( 1.0 ), mFontColor( QColor( 0, 0, 0 ) ),
+  mHAlignment( Qt::AlignLeft ), mVAlignment( Qt::AlignTop ),
+  mExpressionFeature( 0 ), mExpressionLayer( 0 )
 {
   //default font size is 10 point
   mFont.setPointSizeF( 10 );
@@ -75,11 +78,17 @@ void QgsComposerLabel::setText( const QString& text )
   emit itemChanged();
 }
 
+void QgsComposerLabel::setExpressionContext( QgsFeature* feature, QgsVectorLayer* layer )
+{
+  mExpressionFeature = feature;
+  mExpressionLayer = layer;
+}
+
 QString QgsComposerLabel::displayText() const
 {
   QString displayText = mText;
   replaceDateText( displayText );
-  return displayText;
+  return QgsExpression::replaceExpressionText( displayText, mExpressionFeature, mExpressionLayer );
 }
 
 void QgsComposerLabel::replaceDateText( QString& text ) const

src/core/composer/qgscomposerlabel.h

@@ -19,6 +19,9 @@
 
 #include "qgscomposeritem.h"
 
+class QgsVectorLayer;
+class QgsFeature;
+
 /** \ingroup MapComposer
  * A label that can be placed onto a map composition.
  */
@@ -45,6 +48,8 @@ class CORE_EXPORT QgsComposerLabel: public QgsComposerItem
       @note this function was added in version 1.2*/
     QString displayText() const;
 
+    void setExpressionContext( QgsFeature* feature, QgsVectorLayer* layer );
+
     QFont font() const;
     void setFont( const QFont& f );
     /** Accessor for the vertical alignment of the label
@@ -120,6 +125,9 @@ class CORE_EXPORT QgsComposerLabel: public QgsComposerItem
     double mTextBoxWidth;
     /**Height of the text box. This is different to rectangle().height() in case there is rotation*/
     double mTextBoxHeight;
+
+    QgsFeature* mExpressionFeature;
+    QgsVectorLayer* mExpressionLayer;
 };
 
 #endif

src/core/composer/qgscomposition.cpp

@@ -28,6 +28,7 @@
 #include "qgscomposerpicture.h"
 #include "qgscomposerscalebar.h"
 #include "qgscomposershape.h"
+#include "qgscomposerlabel.h"
 #include "qgscomposerattributetable.h"
 #include "qgsaddremovemultiframecommand.h"
 #include "qgscomposermultiframecommand.h"
@@ -57,6 +58,8 @@ struct QgsAtlasRendering::QgsAtlasRenderingImpl
   QgsRectangle origExtent;
   bool restoreLayer;
   std::auto_ptr<QgsExpression> filenameExpr;
+  size_t pageNumber;
+  size_t numberOfPages;
 };
 
 QgsAtlasRendering::QgsAtlasRendering( QgsComposition* composition )
@@ -125,6 +128,10 @@ void QgsAtlasRendering::begin( const QString& filenamePattern )
       layerSet.removeAt( removeAt );
     }
   }
+
+  // special columns for expressions
+  QgsExpression::setSpecialColumn( "$numfeatures", QVariant( (int)impl->nFeatures ) );
+  QgsExpression::setSpecialColumn( "$numpages", QVariant( (int)impl->composition->numPages() ) );
 }
 
 void QgsAtlasRendering::prepareForFeature( size_t featureI )
@@ -133,6 +140,7 @@ void QgsAtlasRendering::prepareForFeature( size_t featureI )
 
     if ( impl->filenamePattern.size() > 0 )
     {
+      QgsExpression::setSpecialColumn( "$feature", QVariant( (int)featureI + 1 ) );
       QVariant filenameRes = impl->filenameExpr->evaluate( &*fit );
       if ( impl->filenameExpr->hasEvalError() )
       {
@@ -204,7 +212,20 @@ void QgsAtlasRendering::prepareForFeature( size_t featureI )
 	new_extent.scale( 1 + impl->composition->atlasMap()->atlasMargin() );
       }
     }
-    impl->composition->atlasMap()->setNewExtent( new_extent );   
+
+    // evaluate label expressions
+    QList<QgsComposerLabel*> labels;
+    impl->composition->composerItems( labels );
+    QgsExpression::setSpecialColumn( "$feature", QVariant( (int)featureI + 1 ) );
+    for ( QList<QgsComposerLabel*>::iterator lit = labels.begin(); lit != labels.end(); ++lit )
+    {
+      QgsExpression::setSpecialColumn( "$page", QVariant( (int)impl->composition->itemPageNumber( *lit ) + 1 ) );
+      (*lit)->setExpressionContext( fit, impl->composition->atlasMap()->atlasCoverageLayer() );
+    }
+
+
+    // set the new extent (and render)
+    impl->composition->atlasMap()->setNewExtent( new_extent );
 }
 
 size_t QgsAtlasRendering::numFeatures() const
@@ -212,13 +233,21 @@ size_t QgsAtlasRendering::numFeatures() const
   return impl->nFeatures;
 }
 
-QString QgsAtlasRendering::currentFilename() const
+const QString& QgsAtlasRendering::currentFilename() const
 {
   return impl->currentFilename;
 }
 
 void QgsAtlasRendering::end()
 {
+  // reset label expression contexts
+  QList<QgsComposerLabel*> labels;
+  impl->composition->composerItems( labels );
+  for ( QList<QgsComposerLabel*>::iterator lit = labels.begin(); lit != labels.end(); ++lit )
+  {
+    (*lit)->setExpressionContext( 0, 0 );
+  }
+
   // restore the coverage visibility
   if ( impl->restoreLayer )
   {
@@ -242,6 +271,11 @@ QgsComposition::QgsComposition( QgsMapRenderer* mapRenderer ) :
 
   mPrintResolution = 300; //hardcoded default
   loadSettings();
+
+  QgsExpression::setSpecialColumn( "$page", QVariant((int)0) );
+  QgsExpression::setSpecialColumn( "$feature", QVariant((int)0) );
+  QgsExpression::setSpecialColumn( "$numpages", QVariant((int)0) );
+  QgsExpression::setSpecialColumn( "$numfeatures", QVariant((int)0) );
 }
 
 QgsComposition::QgsComposition():
@@ -250,6 +284,11 @@ QgsComposition::QgsComposition():
   mAtlasMap( 0 )
 {
   loadSettings();
+
+  QgsExpression::setSpecialColumn( "$page", QVariant((int)0) );
+  QgsExpression::setSpecialColumn( "$feature", QVariant((int)0) );
+  QgsExpression::setSpecialColumn( "$numpages", QVariant((int)0) );
+  QgsExpression::setSpecialColumn( "$numfeatures", QVariant((int)0) );
 }
 
 QgsComposition::~QgsComposition()
@@ -341,6 +380,16 @@ QgsComposerItem* QgsComposition::composerItemAt( const QPointF & position )
   return 0;
 }
 
+int QgsComposition::pageNumberAt( const QPointF& position ) const
+{
+  return position.y() / (paperHeight() + spaceBetweenPages() );
+}
+
+int QgsComposition::itemPageNumber( const QgsComposerItem* item ) const
+{
+  return pageNumberAt( QPointF( item->transform().dx(), item->transform().dy()) );
+}
+
 QList<QgsComposerItem*> QgsComposition::selectedComposerItems()
 {
   QList<QgsComposerItem*> composerItemList;

src/core/composer/qgscomposition.h

@@ -59,7 +59,8 @@ class QgsAtlasRendering
 
   size_t numFeatures() const;
   void prepareForFeature( size_t i );
-  QString currentFilename() const;
+
+  const QString& currentFilename() const;
 
  private:
   struct QgsAtlasRenderingImpl;
@@ -136,6 +137,12 @@ class CORE_EXPORT QgsComposition: public QGraphicsScene
     /**Returns the topmost composer item. Ignores mPaperItem*/
     QgsComposerItem* composerItemAt( const QPointF & position );
 
+    /** Returns the page number (0-bsaed) given a coordinate */
+    int pageNumberAt( const QPointF& position ) const;
+
+    /** Returns on which page number (0-based) is displayed an item */
+    int itemPageNumber( const QgsComposerItem* ) const;
+
     QList<QgsComposerItem*> selectedComposerItems();
 
     /**Returns pointers to all composer maps in the scene*/

src/gui/qgsexpressionbuilderwidget.cpp

@@ -97,6 +97,13 @@ QgsExpressionBuilderWidget::QgsExpressionBuilderWidget( QWidget *parent )
     registerItem( func.mGroup, func.mName, " " + name + " " );
   }
 
+  QList<QgsExpression::FunctionDef> specials = QgsExpression::specialColumns();
+  for ( int i = 0; i < specials.size(); ++i )
+  {
+    QString name = specials[i].mName;
+    registerItem( specials[i].mGroup, name, " " + name + " " );
+  }
+
 #if QT_VERSION >= 0x040700
   txtSearchEdit->setPlaceholderText( tr( "Search" ) );
 #endif

src/ui/qgscomposerlabelwidgetbase.ui

@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>274</width>
+    <width>307</width>
-    <height>488</height>
+    <height>525</height>
    </rect>
   </property>
   <property name="sizePolicy">
@@ -30,8 +30,8 @@
        <rect>
         <x>0</x>
         <y>0</y>
-        <width>271</width>
+        <width>276</width>
-        <height>470</height>
+        <height>503</height>
        </rect>
       </property>
       <attribute name="label">
@@ -45,14 +45,14 @@
          </property>
         </widget>
        </item>
-       <item row="2" column="0" colspan="2">
+       <item row="3" column="0" colspan="2">
         <widget class="QPushButton" name="mFontColorButton">
          <property name="text">
           <string>Font color...</string>
          </property>
         </widget>
        </item>
-       <item row="3" column="0" colspan="2">
+       <item row="4" column="0" colspan="2">
         <widget class="QGroupBox" name="buttonGroup1">
          <property name="title">
           <string>Horizontal Alignment:</string>
@@ -98,7 +98,7 @@
          </layout>
         </widget>
        </item>
-       <item row="4" column="0" colspan="2">
+       <item row="5" column="0" colspan="2">
         <widget class="QGroupBox" name="buttonGroup2">
          <property name="title">
           <string>Vertical Alignment:</string>
@@ -141,7 +141,7 @@
          </layout>
         </widget>
        </item>
-       <item row="5" column="0" colspan="2">
+       <item row="6" column="0" colspan="2">
         <widget class="QDoubleSpinBox" name="mMarginDoubleSpinBox">
          <property name="prefix">
           <string>Margin </string>
@@ -151,7 +151,7 @@
          </property>
         </widget>
        </item>
-       <item row="6" column="0">
+       <item row="7" column="0">
         <widget class="QLabel" name="mRotationLabel">
          <property name="sizePolicy">
           <sizepolicy hsizetype="Minimum" vsizetype="Preferred">
@@ -170,14 +170,14 @@
          </property>
         </widget>
        </item>
-       <item row="6" column="1">
+       <item row="7" column="1">
         <widget class="QDoubleSpinBox" name="mRotationSpinBox">
          <property name="maximum">
           <double>360.000000000000000</double>
          </property>
         </widget>
        </item>
-       <item row="1" column="0" colspan="2">
+       <item row="2" column="0" colspan="2">
         <widget class="QPushButton" name="mFontButton">
          <property name="sizePolicy">
           <sizepolicy hsizetype="Preferred" vsizetype="Fixed">
@@ -190,6 +190,13 @@
          </property>
         </widget>
        </item>
+       <item row="1" column="0" colspan="2">
+        <widget class="QPushButton" name="mInsertExpressionButton">
+         <property name="text">
+          <string>Insert an expression</string>
+         </property>
+        </widget>
+       </item>
       </layout>
      </widget>
     </widget>