[composer] Fix calculation of visible row ranges in QgsComposerTableV2

(Sponsored by City of Uster, Switzerland)
qgis · Sep 17, 2014 · 8171525 · 8171525
1 parent 7d63ade
commit 8171525
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Showing 3 changed files with 59 additions and 7 deletions.
diff --git a/src/core/composer/qgscomposerframe.h b/src/core/composer/qgscomposerframe.h
@@ -49,6 +49,13 @@ class CORE_EXPORT QgsComposerFrame: public QgsComposerItem
     //Overriden to handle fixed frame sizes set by multi frame
     void setSceneRect( const QRectF& rectangle );
 
+    /**Returns the visible portion of the multi frame's content which
+     * is shown in this frame.
+     * @returns extent of visible portion
+     * @note added in QGIS 2.5
+     */
+    QRectF extent() const { return mSection; }
+
   private:
     QgsComposerFrame(); //forbidden
     QgsComposerMultiFrame* mMultiFrame;

diff --git a/src/core/composer/qgscomposertablev2.cpp b/src/core/composer/qgscomposertablev2.cpp
@@ -136,20 +136,60 @@ QSizeF QgsComposerTableV2::totalSize() const
   return mTableSize;
 }
 
+int QgsComposerTableV2::rowsVisible( const int frameIndex ) const
+{
+  //get frame extent
+  if ( frameIndex >= frameCount() )
+  {
+    return 0;
+  }
+  QRectF frameExtent = frame( frameIndex )->extent();
+
+  //calculate header height
+  double headerHeight = 0;
+  if (( mHeaderMode == QgsComposerTableV2::FirstFrame && frameIndex < 1 )
+      || ( mHeaderMode == QgsComposerTableV2::AllFrames ) )
+  {
+    //frame has a header
+    headerHeight = 2 * ( mShowGrid ? mGridStrokeWidth : 0 ) + 2 * mCellMargin +  QgsComposerUtils::fontAscentMM( mHeaderFont );
+  }
+  else
+  {
+    //frame has no header text, just the stroke
+    headerHeight = ( mShowGrid ? mGridStrokeWidth : 0 );
+  }
+
+  //remaining height available for content rows
+  double contentHeight = frameExtent.height() - headerHeight;
+
+  //calculate number of visible rows
+  double rowHeight = ( mShowGrid ? mGridStrokeWidth : 0 ) + 2 * mCellMargin + QgsComposerUtils::fontAscentMM( mContentFont );
+  return qMax( floor( contentHeight / rowHeight ), 0.0 );
+}
 
 QPair< int, int > QgsComposerTableV2::rowRange( const QRectF extent, const int frameIndex ) const
 {
   //calculate row height
-  //TODO - need to traverse all previous frames to calculate what is visible in each
-  //as the entire height of a frame may not be used for content
-  double headerHeight = 0;
-  double firstHeaderHeight = 2 * ( mShowGrid ? mGridStrokeWidth : 0 ) + 2 * mCellMargin +  QgsComposerUtils::fontAscentMM( mHeaderFont );
+  if ( frameIndex >= frameCount() )
+  {
+    //bad frame index
+    return qMakePair( 0 , 0 );
+  }
+
+  //loop through all previous frames to calculate how many rows are visible in each
+  //as the entire height of a frame may not be utilised for content rows
+  int rowsAlreadyShown = 0;
+  for ( int idx = 0; idx < frameIndex; ++idx )
+  {
+    rowsAlreadyShown += rowsVisible( idx );
+  }
 
+  double headerHeight = 0;
   if (( mHeaderMode == QgsComposerTableV2::FirstFrame && frameIndex < 1 )
       || ( mHeaderMode == QgsComposerTableV2::AllFrames ) )
   {
     //frame has a header
-    headerHeight = firstHeaderHeight;
+    headerHeight = 2 * ( mShowGrid ? mGridStrokeWidth : 0 ) + 2 * mCellMargin +  QgsComposerUtils::fontAscentMM( mHeaderFont );
   }
   else
   {
@@ -161,7 +201,7 @@ QPair< int, int > QgsComposerTableV2::rowRange( const QRectF extent, const int f
   double rowHeight = ( mShowGrid ? mGridStrokeWidth : 0 ) + 2 * mCellMargin + QgsComposerUtils::fontAscentMM( mContentFont );
 
   //using zero based indexes
-  int firstVisible = qMax( floor(( extent.top() - firstHeaderHeight )  / rowHeight ), 0.0 );
+  int firstVisible = qMin( rowsAlreadyShown, mTableContents.length() );
   int rowsVisible = qMax( floor( contentHeight / rowHeight ), 0.0 );
   int lastVisible = qMin( firstVisible + rowsVisible, mTableContents.length() );
 

diff --git a/src/core/composer/qgscomposertablev2.h b/src/core/composer/qgscomposertablev2.h
@@ -50,7 +50,6 @@ class CORE_EXPORT QgsComposerTableV2: public QgsComposerMultiFrame
 {
     Q_OBJECT
 
-
   public:
 
     /*! Controls how headers are horizontally aligned in a table
@@ -324,6 +323,12 @@ class CORE_EXPORT QgsComposerTableV2: public QgsComposerMultiFrame
 
     double totalHeight() const;
 
+    /**Calculates how many content rows are visible within a given frame
+     * @param frameIndex index number for frame
+     * @returns number of visible content rows (excludes header rows)
+     */
+    int rowsVisible( const int frameIndex ) const;
+
     /**Calculates a range of rows which should be visible in a given
      * rectangle.
      * @param extent visible extent