Dynamically animate a layout

Question

I have to implement a (child) layout translate animation programmatically because the distance to translate is determined at runtime. I have set the following translate animation

    TranslateAnimation tanim = new TranslateAnimation(
        TranslateAnimation.ABSOLUTE, 0.0f,
        TranslateAnimation.ABSOLUTE, 0.0f,
        TranslateAnimation.ABSOLUTE, 0.0f,
        TranslateAnimation.ABSOLUTE, 100);

to slide down the layout, for example.

Problem 1: This layout will snap back to its original position after the animation finishes. Is there anything I should set to maintain its position? I suspect this is caused by the layout being moved out of the parent layout (parent layout has parameter layout_width="wrap_content"). If this is the case how can I adjust the parent layout to accomodate the child layout change?

Problem 2: Do I have to provide a custom interpolator class to achieve a decelerating effect? If yes, do you know where can I find an example? In xml I can do this

android:interpolator="@android:anim/accelerate_interpolator"

Is there an equivalent Android code to achieve the accelerate/decelerate effect programmatically?

You have to set the `Layout Params` of the layout to the new position, because `Translate Animation` just move the pixels not the view/layout,infact your layout will be at its original position but not visible — Muhammad Babar, May 07 '13 at 07:18
That is actually a problem I'm now having. Can you show some example on how to move my click-sensitive area,say, 100dp down the original layout? — Neoh, May 08 '13 at 02:38
Yes here is a complete answer i have given with example code http://stackoverflow.com/a/15880375/1939564 — Muhammad Babar, May 08 '13 at 08:05

score 2 · Accepted Answer · answered May 04 '13 at 03:04

to keep the position after the animation you need to use the fillAfter attribute. And yes there are Accelerate and Decelerate interpolater classes within the public APIs

TranslateAnimation tanim = new TranslateAnimation(
        TranslateAnimation.ABSOLUTE, 0.0f,
        TranslateAnimation.ABSOLUTE, 0.0f,
        TranslateAnimation.ABSOLUTE, 0.0f,
        TranslateAnimation.ABSOLUTE, 100);
tanim.setFillAfter(true);
tanim.setInterpolater(new DecelerateInterpolator());
//tanim.setInterpolater(new AccelerateInterpolator());

See the Animation docs for info about fillAfter and the Interpolator docs for a list of the built in Interpolator objects within the system.

**fillAfter** just kept the movement of the pixels not the actual layout, you have to set the `Layout Params` of the view/layout to move it to the new position — Muhammad Babar, May 07 '13 at 07:14

Dynamically animate a layout

1 Answers1