Actionscript 3, rotate object on drag
I have an object I need to rotate by clicking and dragging. Following some AS2 code I got the object to rotate a bit every time the mouse is clicked, but can't get it to work with drag.
needle.addEventListener(MouseEvent.MOUSE_DOWN, fl_ClickToDrag_2);
stage.addEventListener(MouseEvent.MOUSE_UP, fl_ReleaseToDrop_2);
function fl_ClickToDrag_2(event:MouseEvent):void
{
var angle = Math.atan2(mouseY-needle.y,mouseX-needle.x);
// apply rotation to handle by converting angle into degrees
needle.rotation = angle*180/Math.PI;
// rotate the grip opposite the handle so it won't rotate along with it
//this.grip._rotation = -this._rotation;
}开发者_开发知识库
function fl_ReleaseToDrop_2(event:MouseEvent):void
{
needle.stopDrag();
}
Well the problem I see is that the MOUSE_DOWN
event only fires once per click, so you only run the code in the handler once.
There could be a better way than this but this is how I'd consider doing it:
EDITED FOR DETAIL:
public class Test extends MovieClip {
private var n:Needle;
public function Test() {
// constructor code
n = new Needle();
stage.addEventListener(MouseEvent.MOUSE_DOWN,mouseDownF,false,0,true);
stage.addEventListener(MouseEvent.MOUSE_UP,mouseUpF,false,0,true);
n.x = stage.stageWidth/2; //center needle on stage
n.y = stage.stageHeight/2;
addChild(n); //add needle to stage
}
public function mouseDownF(e:MouseEvent):void {
stage.addEventListener(MouseEvent.MOUSE_MOVE,rotate,false,0,true);
}
public function rotate(e:MouseEvent):void {
var angle:Number = Math.atan2(mouseY - n.y,mouseX - n.x); //get angle in radians (pythagoras)
angle = angle * 180/Math.PI -90; //convert to degrees , the 90 is to have it point to the mouse
n.rotation = angle; //rotate
}
public function mouseUpF(e:MouseEvent):void {
stage.removeEventListener(MouseEvent.MOUSE_MOVE,rotate);
}
}
So when the user clicks down (mouseDown
) it activates an event listener that fires the rotate
handler every time the mouse moves. When the user lets go of the click the event listener is destroyed. The false,0,true);
when adding the event listener is to make it a weakly referenced listener so that it gets collected by the garbage collector and doesn't just sit in memory taking up space forever.
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