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inside custom component

Java Development

Regular Contributor
Posts: 98
Registered: ‎03-10-2011
My Device: 9700 Bold




I have implemented a simple map within an application of mine however I am unsure how to add interaction with the map so a user is able to pan around the map or zoom in and out. The code I have implemented is as follows:



MapField _mapField;

       int _prevZoom = 3;
       Coordinates c = new Coordinates(51.554928, -0.108361, 0);
       _mapField = new MapField(Field.FOCUSABLE){
    	   protected void paint(Graphics graphics) {
    		   Bitmap mIcon = Bitmap.getBitmapResource("stadium_icon.png");;
    		   XYRect mDest = null;
    	    	if (null != mIcon) {
    	    		if (null == mDest) {
    	    			XYPoint fieldOut = new XYPoint();
    	    			convertWorldToField(getCoordinates(), fieldOut);
    	    			int imgW = mIcon.getWidth();
    	    			int imgH = mIcon.getHeight();
    	    			mDest = new XYRect(fieldOut.x - imgW / 2, 
    	    			fieldOut.y - imgH, imgW, imgH);
    	    		graphics.drawBitmap(mDest, mIcon, 0, 0);



How do I add zoom and pan usability to this code?



Posts: 4,764
Registered: ‎07-21-2008
My Device: Not Specified

Re: Maps

If it were me, would probably override navigationMovement() in order to detect the trackball movement, then adjust the map center position accordingly (translating the dx/dy values into map coordinates).


For zoom, you might detect navigationClick() to toggle between pan and zoom modes, then use your navigationMovement to adjust the zoom level.