From eqqon

Revision as of 12:25, 27 October 2007 (view source) Henon (Talk | contribs) (New page: = Piccolo Nodes = == PComposite == The PComposite node and all of it's Children act like a single PNode. All user interaction, even if it happened on a child node, is handled by the compo...) ← Older edit		Revision as of 21:31, 28 October 2007 (view source) Henon (Talk | contribs) Newer edit →
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-	= Piccolo Nodes =	+	= Useful Piccolo Extensions =
		+	== MouseWheelScrollController ==
		+	This class replaces Piccolo's default zoom event handler which is not very attractive with a mouse wheel zoom event handler. Just instanciate it with your canvas' camera as parameter and mouse wheel zooming just works!
-	== PComposite ==	+	<pre>
-	The PComposite node and all of it's Children act like a single PNode. All user interaction, even if it happened on a child node, is handled by the composite node. For instance, if you add a PDragInputHandler to the composite and drag it all its children get dragged too.	+	public class MouseWheelZoomController
		+	{
		+	public static float MIN_SCALE = .0001f;
		+	public static float MAX_SCALE = 2500;
		+	PCamera camera;
		+
		+	public MouseWheelZoomController(PCamera camera)
		+	{
		+	this.camera = camera;
		+	camera.Canvas.ZoomEventHandler = null;
		+	camera.MouseWheel += OnMouseWheel;
		+	}
		+
		+	public void OnMouseWheel(object o, PInputEventArgs ea)
		+	{
		+	float currentScale = camera.ViewScale;
		+	float scaleDelta = (1.0f + (0.001f * ea.WheelDelta));
		+	float newScale = currentScale * scaleDelta;
		+	if (newScale < MIN_SCALE)
		+	{
		+	camera.ViewScale = MIN_SCALE;
		+	return;
		+	}
		+	if ((MAX_SCALE > 0) && (newScale > MAX_SCALE))
		+	{
		+	camera.ViewScale = MAX_SCALE;
		+	return;
		+	}
		+	PointF pos = ea.Position;
		+	camera.ScaleViewBy(scaleDelta, pos.X, pos.Y);
		+	}
		+	}
		+	</pre>

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Revision as of 21:31, 28 October 2007

Useful Piccolo Extensions

MouseWheelScrollController

This class replaces Piccolo's default zoom event handler which is not very attractive with a mouse wheel zoom event handler. Just instanciate it with your canvas' camera as parameter and mouse wheel zooming just works!

    public class MouseWheelZoomController
    {
        public static float MIN_SCALE = .0001f;
        public static float MAX_SCALE = 2500;
        PCamera camera;

        public MouseWheelZoomController(PCamera camera)
        {
            this.camera = camera;
            camera.Canvas.ZoomEventHandler = null;
            camera.MouseWheel += OnMouseWheel;
        }

        public void OnMouseWheel(object o, PInputEventArgs ea)
        {
            float currentScale = camera.ViewScale;
            float scaleDelta = (1.0f + (0.001f * ea.WheelDelta));
            float newScale = currentScale * scaleDelta;
            if (newScale < MIN_SCALE)
            {
                camera.ViewScale = MIN_SCALE;
                return;
            }
            if ((MAX_SCALE > 0) && (newScale > MAX_SCALE))
            {
                camera.ViewScale = MAX_SCALE;
                return;
            }
            PointF pos = ea.Position;
            camera.ScaleViewBy(scaleDelta, pos.X, pos.Y);
        }
    }