Re: [Geotools-gt2-users] need help for zoom function

[dadar <iam...@ya...>]

Michael, I have some problem about my function. when I try to getScaleX() i
have an error java.lang.NullPointerException
I try to make zoom in function right after i set my style.
am I wrong about that? or is there any other way to getScaleX??
I change the function where I found in ZoomInTool.java so I don't need to
click the mouse to zoom in

public void finalizestyle(){
         Rule otherRule = createRule(LINE_COLOUR, FILL_COLOUR,false);
         otherRule.setElseFilter(true);
         fixfts.rules().add(otherRule);
         stylefinal.featureTypeStyles().add(fixfts);
         mapFrame.getMapContext().getLayer(0).setStyle(stylefinal);
         mapFrame.getMapPane().repaint();

        Rectangle paneArea = mapFrame.getMapPane().getVisibleRect();


        double scale =
mapFrame.getMapPane().getWorldToScreenTransform().getScaleX();
        double newScale = scale * 5;

        DirectPosition2D corner = new DirectPosition2D(
                posisix[0] - 0.5d * paneArea.getWidth() / newScale,
                posisiy[0] + 0.5d * paneArea.getHeight() / newScale);

        DirectPosition2D mapPos = null;
        mapPos.x=posisix[0];
        mapPos.y=posisiy[0];
        Envelope2D newMapArea = new Envelope2D();
        newMapArea.setFrameFromCenter(mapPos, corner);
        mapFrame.getMapPane().setDisplayArea(newMapArea);

         
     }

Darmawan

mbedward wrote:
> 
> Hi Darmawan,
> 
> Really all that happens with the zoom in and zoom out cursor tools is
> that they work out the new map bounds (as a ReferencedEnvelope) and
> then call JMapPane.setDisplayArea.
> 
> Perhaps the easiest thing for you to do is look at the source code for
> ZoomInTool, ZoomOutTool, and their base class AbstractZoomTool. You
> can find them all here...
> 
> http://svn.osgeo.org/geotools/tags/2.6.0/modules/unsupported/swing/src/main/java/org/geotools/swing/tool/
> 
> When using ZoomInTool you can draw a box on the map pane with the
> mouse to define the area to zoom in to. The code that draws the box is
> part of the JMapPane class so you don't need to implement that
> yourself.
> 
> Michael
> 
> ------------------------------------------------------------------------------
> Come build with us! The BlackBerry(R) Developer Conference in SF, CA
> is the only developer event you need to attend this year. Jumpstart your
> developing skills, take BlackBerry mobile applications to market and stay 
> ahead of the curve. Join us from November 9 - 12, 2009. Register now!
> http://p.sf.net/sfu/devconference
> _______________________________________________
> Geotools-gt2-users mailing list
> Geo...@li...
> https://lists.sourceforge.net/lists/listinfo/geotools-gt2-users
> 
> 

-- 
View this message in context: http://n2.nabble.com/need-help-for-zoom-function-tp3917169p3927271.html
Sent from the geotools-gt2-users mailing list archive at Nabble.com.