Education Prize Logo
Science SPORE Prize
November 2011

NSF Logo
The Open Source Physics Project is supported by NSF DUE-0442581.

Question about dragable and interactive Objects post and replies

Return to the Question about dragable and interactive Objects thread
Login to post to this thread

Interactive 2D shapes question - Nov 6, 2011 at 1:25AM
Eduardo Garcia
13 Posts

Hello again:

I am trying to do some interactive 2D shapes, like buttons that change color for example, in EJS.

I am having a problem with making them "clickable". If I choose the 2DShape to not be dragable, the object I make cannot be made clickable, so I can't execute functions when the user clicks on it.

The only way I have found to make them clickable is to make them dragable in either direction. If I choose "Dragable: ENABLED_NONE" they become not clickable.

Is there a way to make them clickable but not dragable?

Thank you for your time and patience.

Replies to Interactive 2D shapes question

Re: Interactive 2D shapes question - Nov 07 2011 1:24PM
Francisco Esquembre
105 Posts

Hum! (That's my favorite expression when someone asks for something I had not foreseen :-) )

Yes. ENABLED_NONE makes the object not insensitive to clicks.

If you enable it, you risk the user will move it in the X direction, in the Y direction, or both.

No other possibility, I am afraid. At least not yet. I would need to implement this if we find this is a good idea.

There is a workaround, though. Set the "Draggable" property to ENABLED_X. And if xPos[] is the array of the positions of the elements of the set and if you click on a given index, force the value of xPos[index] in the "On drag"action. This has the effect of repositioning the element in case the user moved it.

It's not very clean, but it should work.

If you insist, I can implement a new "Draggable" option, one that makes it responsive (i.e. clickable) but will not let the user move it at all.


Re: Re: Interactive 2D shapes question - Nov 12 2011 7:45PM
Eduardo Garcia
13 Posts


Thank you for your response, your solution works nicely!

Re: Interactive 2D shapes question - Jan 07 2012 12:43PM
Geraggelos Thanasis
1 Posts

I think there is a simpler way.
You can define a variable lets say (v)  which is the X or Y position of another object
Now if you define the clickable object position X or Y indirect, lets say (v+10)
it is clickable and not dragable. That is what I use in my models.

Geraggelos Thanasis

Post edited January 7, 2012 at 12:46 PM EST.

Re: Re: Interactive 2D shapes question - Jan 13 2012 12:54PM
Francisco Esquembre
105 Posts

Brilliant, Geraggelos!

Actually, you could use the variable of its own position (say x) and set the property to x+0.


PS: No, I didn't design it like this on purpose! :-)

Post edited January 13, 2012 at 12:50 PM EST.

The OSP Network:
Open Source Physics - Tracker - EJS Modeling
Physlet Physics
Physlet Quantum Physics