Button that Reacts to a Mouse
This applet shows a black button that starts to change colors with time
when the user's mouse moves over it. When the user clicks on the button with
the left mouse button, the applet takes a snapshot of the time-varying color.
When the user moves the mouse away from the button, its color returns to black.
This applet illustrates the following:
- creating a solid-colored square.
- making that square react to mouse over and left mouse button clicks.
import com.ms.dxmedia.*; All DirectAnimation classes
|
| ButtonPick is an applet that invokes ButtonPickModel which constructs a
solid-colored square. |
public class ButtonPick extends DXMApplet {
public void init() {
super.init() ;
setModel (new ButtonPickModel());
}
}
| In the ButtonPickModel class the createModel method is where you construct
your animation. |
class ButtonPickModel extends Model {
public void createModel(BvrsToRun blist)
{
| Create a detectable image and crop it to 100 by 100 pixels. |
ImageBvr detectImg = detectableEmptyImage.
crop(point2(mul(toBvr(-50),pixelBvr), mul(toBvr(-50),pixelBvr)),
point2(mul(toBvr(50),pixelBvr), mul(toBvr(50),pixelBvr)));
| Make the above created image pickable. |
PickableImage pickPImg = new PickableImage(detectImg);
| Create an event that will trigger when the mouse moves over detectImg. |
DXMEvent pickEv = pickPImg.getPickEvent();
| Create an event that will trigger when both the mouse moves over
detectImg, and the left mouse button is clicked. |
DXMEvent clickEv = andEvent(leftButtonDown, pickEv);
| Create a color behavior that changes its hue with time. |
ColorBvr changeClr = colorHsl(add(mul(sin(
localTime),toBvr(0.5)),toBvr(0.5)),
toBvr(0.5),toBvr(0.5));
| Create a color behavior that starts out as black, changes to changeClr
when the mouse moves over detectImg (pickEv), and returns to black
after the mouse is no longer over detectImg (notEvent(pickEv)). |
ColorBvr overClr = ColorBvr.newUninitBvr();
overClr.init(until(
black,pickEv,until(changeClr,notEvent(pickEv),overClr)));
| Create an event that takes a snapshot of overClr when detectImg is
clicked with the left mouse button. |
DXMEvent snapEv = clickEv.snapshotEvent(overClr);
| Create two color behaviors. One (snapClr) that starts out as overClr,
and changes to whatever color overClr is when detectImg is clicked
with the left mouse button. The second (totalClr) starts out as
snapClr, and changes to black when the mouse is no longer over
detectImg. |
ColorBvr snapClr = (ColorBvr)untilNotify(overClr,snapEv,
new ButtonPickSnapshot());
ColorBvr totalClr = ColorBvr.newUninitBvr();
totalClr.init(until(
snapClr,notEvent(pickEv),totalClr));
| Create a solid color image, crop it to 100 by 100 pixels,
and apply the color behavior of totalClr to it. |
ImageBvr initImg = solidColorImage(totalClr).
crop(point2(mul(toBvr(-50),pixelBvr), mul(toBvr(-50),pixelBvr)),
point2(mul(toBvr(50),pixelBvr), mul(toBvr(50),pixelBvr)));
| Put the pickable Image on top of initImg. |
ImageBvr finalImg = overlay(pickPImg.getImageBvr(),initImg);
| Display the image on a blue background. |
setImage(overlay(finalImg, solidColorImage(blue)));
}
}
class ButtonPickSnapshot extends Statics implements UntilNotifier {
public Behavior notify(Object eventData,
Behavior currentRunningBvr, BvrsToRun btr) {
| Returns the color of overClr when the left mouse button is clicked
on detectImg. |
return (ColorBvr)eventData;
}
}
| Thats all there is to it. Happy animating... |
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