[FEATURE][composer] Add option for controlling placement of rendered images inside a picture item (eg, top left, bottom right, etc)

Author: nyalldawson

python/core/composer/qgscomposerpicture.sip

@@ -117,6 +117,22 @@ class QgsComposerPicture: QgsComposerItem
     */
     ResizeMode resizeMode() const;
 
+    /**Sets the picture's anchor point, which controls how it is placed
+     * within the picture item's frame.
+     * @param anchor anchor point for picture
+     * @note added in 2.3
+     * @see pictureAnchor
+     */
+    void setPictureAnchor( QgsComposerItem::ItemPositionMode anchor );
+
+    /**Returns the picture's current anchor, which controls how it is placed
+     * within the picture item's frame.
+     * @returns anchor point for picture
+     * @note added in 2.3
+     * @see setPictureAnchor
+     */
+    ItemPositionMode pictureAnchor() const;   
+    
     /**Returns whether the picture item is using an expression for the image source.
      * @returns true if the picture is using an expression for the source, false if
      * it is using a single static file path for the source.

src/app/composer/qgscomposerpicturewidget.cpp

@@ -245,6 +245,29 @@ void QgsComposerPictureWidget::on_mResizeModeComboBox_currentIndexChanged( int i
 
   //disable picture rotation for non-zoom modes
   mRotationGroupBox->setEnabled( mPicture->resizeMode() == QgsComposerPicture::Zoom );
+
+  //disable anchor point control for certain zoom modes
+  if ( mPicture->resizeMode() == QgsComposerPicture::Zoom ||
+       mPicture->resizeMode() == QgsComposerPicture::Clip )
+  {
+    mAnchorPointComboBox->setEnabled( true );
+  }
+  else
+  {
+    mAnchorPointComboBox->setEnabled( false );
+  }
+}
+
+void QgsComposerPictureWidget::on_mAnchorPointComboBox_currentIndexChanged( int index )
+{
+  if ( !mPicture )
+  {
+    return;
+  }
+
+  mPicture->beginCommand( tr( "Picture placement changed" ) );
+  mPicture->setPictureAnchor(( QgsComposerItem::ItemPositionMode )index );
+  mPicture->endCommand();
 }
 
 void QgsComposerPictureWidget::on_mRadioPath_clicked()
@@ -422,12 +445,12 @@ void QgsComposerPictureWidget::setGuiElementValues()
     mComposerMapComboBox->blockSignals( true );
     mRotationFromComposerMapCheckBox->blockSignals( true );
     mResizeModeComboBox->blockSignals( true );
+    mAnchorPointComboBox->blockSignals( true );
     mRadioPath->blockSignals( true );
     mRadioExpression->blockSignals( true );
     mPictureExpressionLineEdit->blockSignals( true );
 
     mPictureLineEdit->setText( mPicture->pictureFile() );
-//    QRectF pictureRect = mPicture->rect();
     mPictureRotationSpinBox->setValue( mPicture->pictureRotation() );
 
     refreshMapComboBox();
@@ -455,6 +478,18 @@ void QgsComposerPictureWidget::setGuiElementValues()
     //disable picture rotation for non-zoom modes
     mRotationGroupBox->setEnabled( mPicture->resizeMode() == QgsComposerPicture::Zoom );
 
+    mAnchorPointComboBox->setCurrentIndex(( int )mPicture->pictureAnchor() );
+    //disable anchor point control for certain zoom modes
+    if ( mPicture->resizeMode() == QgsComposerPicture::Zoom ||
+         mPicture->resizeMode() == QgsComposerPicture::Clip )
+    {
+      mAnchorPointComboBox->setEnabled( true );
+    }
+    else
+    {
+      mAnchorPointComboBox->setEnabled( false );
+    }
+
     mRadioPath->setChecked( !( mPicture->usePictureExpression() ) );
     mRadioExpression->setChecked( mPicture->usePictureExpression() );
     mPictureLineEdit->setEnabled( !( mPicture->usePictureExpression() ) );
@@ -469,6 +504,7 @@ void QgsComposerPictureWidget::setGuiElementValues()
     mPictureLineEdit->blockSignals( false );
     mComposerMapComboBox->blockSignals( false );
     mResizeModeComboBox->blockSignals( false );
+    mAnchorPointComboBox->blockSignals( false );
     mRadioPath->blockSignals( false );
     mRadioExpression->blockSignals( false );
     mPictureExpressionLineEdit->blockSignals( false );

src/app/composer/qgscomposerpicturewidget.h

@@ -30,6 +30,7 @@ class QgsComposerPictureWidget: public QWidget, private Ui::QgsComposerPictureWi
     Q_OBJECT
 
   public:
+
     QgsComposerPictureWidget( QgsComposerPicture* picture );
     ~QgsComposerPictureWidget();
 
@@ -47,6 +48,7 @@ class QgsComposerPictureWidget: public QWidget, private Ui::QgsComposerPictureWi
     void on_mRotationFromComposerMapCheckBox_stateChanged( int state );
     void on_mComposerMapComboBox_activated( const QString & text );
     void on_mResizeModeComboBox_currentIndexChanged( int index );
+    void on_mAnchorPointComboBox_currentIndexChanged( int index );
     void on_mRadioPath_clicked();
     void on_mRadioExpression_clicked();
     void setPictureExpression();

src/core/composer/qgscomposerpicture.cpp

@@ -38,6 +38,7 @@ QgsComposerPicture::QgsComposerPicture( QgsComposition *composition ) :
     mPictureRotation( 0 ),
     mRotationMap( 0 ),
     mResizeMode( QgsComposerPicture::Zoom ),
+    mPictureAnchor( UpperLeft ),
     mPictureExpr( 0 )
 {
   mPictureWidth = rect().width();
@@ -50,6 +51,7 @@ QgsComposerPicture::QgsComposerPicture() : QgsComposerItem( 0 ),
     mPictureRotation( 0 ),
     mRotationMap( 0 ),
     mResizeMode( QgsComposerPicture::Zoom ),
+    mPictureAnchor( UpperLeft ),
     mPictureExpr( 0 )
 {
   mPictureHeight = rect().height();
@@ -90,40 +92,99 @@ void QgsComposerPicture::paint( QPainter* painter, const QStyleOptionGraphicsIte
 
   //int newDpi = ( painter->device()->logicalDpiX() + painter->device()->logicalDpiY() ) / 2;
 
+  //picture resizing
   if ( mMode != Unknown )
   {
     double boundRectWidthMM;
     double boundRectHeightMM;
-    double imageRectWidthMM;
-    double imageRectHeightMM;
+    QRect imageRect;
     if ( mResizeMode == QgsComposerPicture::Zoom || mResizeMode == QgsComposerPicture::ZoomResizeFrame )
     {
       boundRectWidthMM = mPictureWidth;
       boundRectHeightMM = mPictureHeight;
-      imageRectWidthMM = mImage.width();
-      imageRectHeightMM = mImage.height();
+      imageRect = QRect( 0, 0, mImage.width(), mImage.height() );
     }
     else if ( mResizeMode == QgsComposerPicture::Stretch )
     {
       boundRectWidthMM = rect().width();
       boundRectHeightMM = rect().height();
-      imageRectWidthMM = mImage.width();
-      imageRectHeightMM = mImage.height();
+      imageRect = QRect( 0, 0, mImage.width(), mImage.height() );
+    }
+    else if ( mResizeMode == QgsComposerPicture::Clip )
+    {
+      boundRectWidthMM = rect().width();
+      boundRectHeightMM = rect().height();
+      int imageRectWidthPixels = mImage.width();
+      int imageRectHeightPixels = mImage.height();
+      imageRect = clippedImageRect( boundRectWidthMM, boundRectHeightMM ,
+                                    QSize( imageRectWidthPixels, imageRectHeightPixels ) );
     }
     else
     {
       boundRectWidthMM = rect().width();
       boundRectHeightMM = rect().height();
-      imageRectWidthMM = rect().width() * mComposition->printResolution() / 25.4;
-      imageRectHeightMM = rect().height() * mComposition->printResolution() / 25.4;
+      imageRect = QRect( 0, 0, rect().width() * mComposition->printResolution() / 25.4,
+                         rect().height() * mComposition->printResolution() / 25.4 );
     }
     painter->save();
 
+    //zoom mode - calculate anchor point and rotation
     if ( mResizeMode == Zoom )
     {
-      painter->translate( rect().width() / 2.0, rect().height() / 2.0 );
-      painter->rotate( mPictureRotation );
-      painter->translate( -boundRectWidthMM / 2.0, -boundRectHeightMM / 2.0 );
+      //TODO - allow placement modes with rotation set. for now, setting a rotation
+      //always places picture in center of frame
+      if ( mPictureRotation != 0 )
+      {
+        painter->translate( rect().width() / 2.0, rect().height() / 2.0 );
+        painter->rotate( mPictureRotation );
+        painter->translate( -boundRectWidthMM / 2.0, -boundRectHeightMM / 2.0 );
+      }
+      else
+      {
+        //shift painter to edge/middle of frame depending on placement
+        double diffX = rect().width() - boundRectWidthMM;
+        double diffY = rect().height() - boundRectHeightMM;
+
+        double dX = 0;
+        double dY = 0;
+        switch ( mPictureAnchor )
+        {
+          case UpperLeft:
+          case MiddleLeft:
+          case LowerLeft:
+            //nothing to do
+            break;
+          case UpperMiddle:
+          case Middle:
+          case LowerMiddle:
+            dX = diffX / 2.0;
+            break;
+          case UpperRight:
+          case MiddleRight:
+          case LowerRight:
+            dX = diffX;
+            break;
+        }
+        switch ( mPictureAnchor )
+        {
+          case UpperLeft:
+          case UpperMiddle:
+          case UpperRight:
+            //nothing to do
+            break;
+          case MiddleLeft:
+          case Middle:
+          case MiddleRight:
+            dY = diffY / 2.0;
+            break;
+          case LowerLeft:
+          case LowerMiddle:
+          case LowerRight:
+            dY = diffY;
+            break;
+        }
+        painter->translate( dX, dY );
+      }
     }
 
     if ( mMode == SVG )
@@ -132,7 +193,7 @@ void QgsComposerPicture::paint( QPainter* painter, const QStyleOptionGraphicsIte
     }
     else if ( mMode == RASTER )
     {
-      painter->drawImage( QRectF( 0, 0, boundRectWidthMM,  boundRectHeightMM ), mImage, QRectF( 0, 0, imageRectWidthMM, imageRectHeightMM ) );
+      painter->drawImage( QRectF( 0, 0, boundRectWidthMM,  boundRectHeightMM ), mImage, imageRect );
     }
 
     painter->restore();
@@ -146,6 +207,64 @@ void QgsComposerPicture::paint( QPainter* painter, const QStyleOptionGraphicsIte
   }
 }
 
+QRect QgsComposerPicture::clippedImageRect( double &boundRectWidthMM, double &boundRectHeightMM, QSize imageRectPixels )
+{
+  int boundRectWidthPixels = boundRectWidthMM * mComposition->printResolution() / 25.4;
+  int boundRectHeightPixels = boundRectHeightMM * mComposition->printResolution() / 25.4;
+
+  //update boundRectWidth/Height so that they exactly match pixel bounds
+  boundRectWidthMM = boundRectWidthPixels * 25.4 / mComposition->printResolution();
+  boundRectHeightMM = boundRectHeightPixels * 25.4 / mComposition->printResolution();
+
+  //calculate part of image which fits in bounds
+  int leftClip = 0;
+  int topClip = 0;
+
+  //calculate left crop
+  switch ( mPictureAnchor )
+  {
+    case UpperLeft:
+    case MiddleLeft:
+    case LowerLeft:
+      leftClip = 0;
+      break;
+    case UpperMiddle:
+    case Middle:
+    case LowerMiddle:
+      leftClip = ( imageRectPixels.width() - boundRectWidthPixels ) / 2;
+      break;
+    case UpperRight:
+    case MiddleRight:
+    case LowerRight:
+      leftClip =  imageRectPixels.width() - boundRectWidthPixels;
+      break;
+  }
+
+  //calculate top crop
+  switch ( mPictureAnchor )
+  {
+    case UpperLeft:
+    case UpperMiddle:
+    case UpperRight:
+      topClip = 0;
+      break;
+    case MiddleLeft:
+    case Middle:
+    case MiddleRight:
+      topClip = ( imageRectPixels.height() - boundRectHeightPixels ) / 2;
+      break;
+    case LowerLeft:
+    case LowerMiddle:
+    case LowerRight:
+      topClip = imageRectPixels.height() - boundRectHeightPixels;
+      break;
+  }
+
+
+  return QRect( leftClip, topClip, boundRectWidthPixels, boundRectHeightPixels );
+
+}
+
 void QgsComposerPicture::setPictureFile( const QString& path )
 {
   mSourceFile.setFileName( path );
@@ -525,6 +644,8 @@ bool QgsComposerPicture::writeXML( QDomElement& elem, QDomDocument & doc ) const
   composerPictureElem.setAttribute( "pictureWidth", QString::number( mPictureWidth ) );
   composerPictureElem.setAttribute( "pictureHeight", QString::number( mPictureHeight ) );
   composerPictureElem.setAttribute( "resizeMode", QString::number(( int )mResizeMode ) );
+  composerPictureElem.setAttribute( "anchorPoint", QString::number(( int )mPictureAnchor ) );
+
   if ( mUseSourceExpression )
   {
     composerPictureElem.setAttribute( "useExpression", "true" );
@@ -561,6 +682,7 @@ bool QgsComposerPicture::readXML( const QDomElement& itemElem, const QDomDocumen
   mPictureWidth = itemElem.attribute( "pictureWidth", "10" ).toDouble();
   mPictureHeight = itemElem.attribute( "pictureHeight", "10" ).toDouble();
   mResizeMode = QgsComposerPicture::ResizeMode( itemElem.attribute( "resizeMode", "0" ).toInt() );
+  mPictureAnchor = QgsComposerItem::ItemPositionMode( itemElem.attribute( "anchorPoint", QString( QgsComposerItem::UpperLeft ) ).toInt() );
 
   QDomNodeList composerItemList = itemElem.elementsByTagName( "ComposerItem" );
   if ( composerItemList.size() > 0 )
@@ -594,8 +716,6 @@ bool QgsComposerPicture::readXML( const QDomElement& itemElem, const QDomDocumen
   QString fileName = QgsProject::instance()->readPath( itemElem.attribute( "file" ) );
   mSourceFile.setFileName( fileName );
 
-  refreshPicture();
-
   //picture rotation
   if ( itemElem.attribute( "pictureRotation", "0" ).toDouble() != 0 )
   {
@@ -619,6 +739,8 @@ bool QgsComposerPicture::readXML( const QDomElement& itemElem, const QDomDocumen
     QObject::connect( mRotationMap, SIGNAL( mapRotationChanged( double ) ), this, SLOT( setRotation( double ) ) );
   }
 
+  refreshPicture();
+
   emit itemChanged();
   return true;
 }
@@ -635,6 +757,12 @@ int QgsComposerPicture::rotationMap() const
   }
 }
 
+void QgsComposerPicture::setPictureAnchor( QgsComposerItem::ItemPositionMode anchor )
+{
+  mPictureAnchor = anchor;
+  update();
+}
+
 bool QgsComposerPicture::imageSizeConsideringRotation( double& width, double& height ) const
 {
   //kept for api compatibility with QGIS 2.0 - use mPictureRotation