Glad to hear it.

thanks david you’re a life saver

It sounds like you’re hoping to constrain dragging to a pie shape. Here’s a quick bit a sample code that should at least get you started. This series of if/if..else statements replaces the existing if statement in the original blog entry:

if (angle < 0) {
  this._x = this.origX + (Math.cos(0) * distance);
  this._y = this.origY + (Math.sin(0) * distance);
} else if (angle > 0.62) {
  this._x = this.origX + (Math.cos(0.62) * distance);
  this._y = this.origY + (Math.sin(0.62) * distance);
} else {
  this._x = _root._xmouse;
  this._y = _root._ymouse;
}

So … whereas the original ActionScript cared about distance, this revision cares about angle. 36 degrees in radians is approximately 0.62, which is why that number is the one shown. In the above, zero points to the right, and 0.62 radians also points to the right, but roughly 36 degrees below due east to an nearly southeast. If the mouse happens to be higher than that (angle < 0), the movie clip is positioned specifically at that angle (zero), at the distance determined by the distance variable. In like fashion, if the mouse happens to be lower (angle &rt; 0.68), the movie clip is positioned right at 0.68 radians at the same distance variable. Otherwise, the movie clip is put wherever the mouse is.

The challenge, here, is how to handle angles at other … angles. The if statements may need to be very much more flexible than the current hard coded 0/0.68 range.

your solution on using startDrag is perfect…but i’m trying to do more startDrag() within an angle but in a straight line let say 36 degree angle

i’m trying to create a fixed movieclip resizer…i got the idea to actually detect the angle between the resizer_mc and the movieclip that i want to resize

can u help me?

Glad to hear it.

I found this technique useful for applying any type of behavioral logic while dragging. ie scrubbing to a new frame in a movieClip while dragging a slider thumb for example.

how would this work if the object did not start in the center of the bounding box, circle, ellipse, etc.?

The center point is completely arbitrary. In my example, I set the origX and origY properties of mc to mc’s original location …

mc.origX = mc._x;
mc.origY = mc._y;

… but you can set those properties to whatever you like. Whatever they are, those values will be the center point of the circle or ellipse. In fact, they don’t even have to be dynamic properties of that movie clip: they can by variables, if you like; I just happened to find it convenient to refer to them via this in the above code.

If I understand what you’re saying, you’d like to know how to contrain the mouse rather than what the mouse is dragging — actually, in addition to what the mouse is dragging. If that’s it, I’m afraid you’re out of luck. The Flash Player has very little control over the mouse itself. ActionScript can understand where the mouse is, and even hide the mouse altogether, but it cannot move or constrain the mouse. Notice that in my examples, the mouse moves wherever the users puts it: only the movie clip is constrained.

That said, you can simulate mouse constraint. The trick there is to draw a movie clip that looks like the mouse arrow, hide the actual mouse arrow (see Mouse.hide()), and constantly position the arrow movie clip where the mouse is. Other dragging will have to be done in addition to that. Make sense?

I suppose to do this, you’d find the distance between the mouse and the center of the circle, when the user clicks, and then somehow constrain the mouse to this distance, while still allowing it to move around the circle. I just don’t know how to make that happen.

Although you can’t constrain the mouse itself, as discussed, that part about finding the distance between the mouse and the center of the circle is already spelled out in the above code (see the formula that sets the value of distance). You may also want to check out How to Drag Clock Hands in a Circle, which may be a little closer to the kind of dragging you’re after — though my article doesn’t include the secondary horizontal slider at the top of yours.

Right now, I’m trying to do something that relates to this post, but I can’t quite figure out if the script in your post can solve my problem, or if I need to do something else.

I have a little scroll wheel that the user can click and “drag” in a circle. It works great, except I’d like it if the user couldn’t move his mouse futher from or closer to the center of the circle while he’s pressing the mouse. Imagine if you have one hand on a steering wheel and are turning it - you’re hand stays on the same place on the wheel. That’s what I want.

I suppose to do this, you’d find the distance between the mouse and the center of the circle, when the user clicks, and then somehow constrain the mouse to this distance, while still allowing it to move around the circle. I just don’t know how to make that happen.

Here is the SWF: http://www.newthinkmedia.com/scroll_wheel.swf
And the AS: http://www.newthinkmedia.com/circle_as.txt

I downloaded this FLA from someone else and modified it slightly - that’s why I can’t quite figure this out. I suppose if I wrote it to begin with, this it would be pretty easy for me and I wouldn’t get a little dizzy every time I try to work it out.

This is where I got the original FLA

Thanks for any help!
Philip