I am using QTextDocument for laying out some HTML text. This text gets rendered onto a QImage and its byte data is used to be displayed somewhere else.

Among other things I need to be able to get the x/y/w/h of a character in that QTextDocument. Based on some code here in the forum I am using the code below, but I am wondering whether there is an easier way to do that...

The class has two member variables:
Qt Code: 
  1. QTextDocument *m_pTextDocument;
  2. QTextCursor *m_pTextCursor;
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And the code is:
Qt Code: 
  1. void CQtTextLayout::GetXYWHOfLayoutIndex( int index, float *flX, float *flY, float *flW, float *flH )
  2. {
  3. 	if( m_pTextCursor )
  4. 	{
  5. 		m_pTextCursor->setPosition( index );
  6.  
  7. 		const QTextBlock textCursorBlock = m_pTextCursor->block();
  8. 		const QRectF blockBoundingRect = m_pTextDocument->documentLayout()->blockBoundingRect( textCursorBlock );
  9. 		QTextFrameFormat rootFrameFormat = m_pTextDocument->rootFrame()->frameFormat();
  10.  
  11. 		const QTextLayout *textCursorBlockLayout = textCursorBlock.layout();
  12. 		const int relativeCursorPositionInBlock = m_pTextCursor->position() - m_pTextCursor->block().position();
  13. 		QTextLine textLine = textCursorBlockLayout->lineForTextPosition( relativeCursorPositionInBlock );
  14.  
  15. 		if ( textLine.isValid() ) {
  16. 			int pos = m_pTextCursor->position() - m_pTextCursor->block().position();
  17. 			*flY = textLine.lineNumber() * textLine.height() + blockBoundingRect.top();
  18. 			*flX = textLine.cursorToX(pos) + rootFrameFormat.leftMargin() + rootFrameFormat.padding();
  19. 			*flW = textLine.cursorToX(pos + 1) + rootFrameFormat.leftMargin() + rootFrameFormat.padding() - *flX;
  20. 			*flH = textLine.height();
  21. 		}
  22. 		else
  23. 		{
  24. 			*flX = 0.0;
  25. 			*flY = 0.0;
  26. 			*flW = 0.0;
  27. 			*flH = 0.0;
  28. 		}
  29. 	}
  30. 	else
  31. 	{
  32. 		*flX = 0.0;
  33. 		*flY = 0.0;
  34. 		*flW = 0.0;
  35. 		*flH = 0.0;
  36. 	}
  37. 	DebugLog( "GetXYWHOfLayoutIndex %.3f %.3f %.3f %.3f", *flX, *flY, *flW, *flH ); 
  38. }
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