Archived:JSR-226 - SVGLocatableElement.getScreenBBox() and SVGLocatableElement.getScreenCTM() may return wrong values for group elements (Known Issue)

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Compatibility

Platform(s): S60 3rd Edition, FP1 MIDP SDK

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Article

Created: User:Technical writer 1 (14 Sep 2007)

Last edited: hamishwillee (29 Jun 2012)

Overview

When using the Scalable 2D Vector Graphics API, the methods SVGLocatableElement.getScreenBBox() and SVGLocatableElement.getScreenCTM() may return wrong values in certain cases.

Description

The box coordinates are in the screen coordinate space, which is connected to the current user coordinate space by the matrix returned by SVGLocatableElement.getScreenCTM(). This happens when the group includes another <group> element which contains transformations.

How to reproduce

This issue affects JSR-226 when running on the emulator.

  <svg viewBox="-100 -100 240 320">
    <g id="group1" transform="translate(10, 20)" fill="red" > 
     <rect id="rect1" transform="scale(2)" x="10" y="10" width="50" height="50"/> 
     <rect id="rect2" x="10" y="10" width="100" height="100"/> 
     <g id="group2" transform="translate(10, 20)" > 
       <rect id="rect3" x="0" y="10" width="150" height="50"/> 
       <circle id="circle1" cx="20" cy="20" r="100" /> 
     </g> 
  </g>
  </svg>
 
  svgImage.setViewportWidth( 240 );
  svgImage.setViewportHeight( 320 );
 
  SVGLocatableElement group1Elem = (SVGLocatableElement)         
  svgImage.getDocument().getElementById( group1 );
 
  SVGRect screenBBox = group1Elem.getScreenBBox();
  SVGMatrix m = group1Elem.getScreenCTM();

The returned values are:

 screenBBox  = [-60, -40, 230, 200]
 m = [1, 0, 0; 1, 10, 20];

The correct values are:

 screenBBox  = [40, 60, 230, 200]
 m =  [1, 0, 0; 1, 110, 120]

Solution

No solution available.