Animation when modifying LinearLayout height

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Animation when modifying LinearLayout height

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#1 by (4 votes)
#2 by (1 votes)

0

I'm modifying the height of a LinearLayout of WRAP_CONTENT for 0 (zero) and vice versa by listening for the event onClick of a Button .

I would like this change to occur gradually over a few milliseconds, such as 700ms , for example. How do I do this using the least amount of code possible?

Code snippet:

    LinearLayout ll = (LinearLayout) findViewById(R.id.teste);
ll.setOnClickListener(new View.onClickListener() {
    @Override
    public void onClick (View v){
        ViewGroup.LayoutParams params = v.getLayoutParams();
        params.height = 0;
        v.setLayoutParams(params);
    }
});

This changes the height to zero, but without transition.

EDIT : The effect looks like this

android android-layout

asked by anonymous 19.02.2017 / 16:15

2 answers

1

Well, as you were specific in the amount of code, the best result would be this:

LinearLayout ll = (LinearLayout) findViewById(R.id.teste);
ll.setOnClickListener(new View.onClickListener() {
    @Override
    public void onClick (View v){
        ViewGroup.LayoutParams params = v.getLayoutParams();
        params.height = 0;
        ll.postDelayed(new Runnable() {
                public void run() {
                    v.setLayoutParams(params);
                }, 700);
        ll.getLayoutParams().height = originaltamanhodoseulayout
    }
});

You need to know the original height of your "ll" to return it to the original alttura later. Explaining:
it runs in the background for 700ms leaving the "ll" with height = 0 and when it finishes it reverts to the original height.

I believe that with lower lines of code would be this, I already use this here with positive result, although for other purposes.

of a confered ae

20.02.2017 / 13:11

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score 4 · Accepted Answer

The answer has four steps:

Get the final size of your container;

Get the initial size;

Create a ValueAnimator to vary from initial size to final size by 700ms;

Set the height value and resize the container at each iteration of ValueAnimator .

Button button = ...; //Seu button
LinearLayout ll = (LinearLayout) findViewById(R.id.teste);

button.setOnClickListener(new View.onClickListener() {
    @Override
    public void onClick (View v){
        final ViewGroup.LayoutParams params = ll.getLayoutParams();

        int finalHeight = 0;
        int initialHeight = ll.getHeight();

        ValueAnimator va = ValueAnimator.ofInt(initialHeight, finalHeight);

        va.setDuration(700);
        va.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
            public void onAnimationUpdate(ValueAnimator animation) {
                params.height = (Integer) animation.getAnimatedValue();
                ll.requestLayout();
            }
        });

        va.start();
    }
});