How to make text on button appear and disappear continualy

Question

I have a button that I want its text appear for 1 second then disappear for 1 second, loop for 6 seconds, here is what I tried:

for(int i = 0 ; i < 6 ; i++) {
    button.setTextSize(18);
    try {
        Thread.sleep(1000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
    button.setTextSize(0);
    try {
        Thread.sleep(1000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

first is it appear that the button's text size became 36 instead of 18,
second is it is does not act as I expected, never show the text,
note: the text size from start is 0.

How can I achieve this?

Dont use thread, It will waste CPU time and decrease performance of the application — Bhoomika Brahmbhatt, May 09 '16 at 08:03
@Selvin I don't think handler will behave as I expected, because after this code the activity end — user3571374, May 09 '16 at 08:07
yes, that's what I want @vrundpurohit, but it is the button, I just want the text on button blink — user3571374, May 09 '16 at 08:09
you can just apply blink animation on your textview. are aware of android animations? — V-rund Puro-hit, May 09 '16 at 08:10

score 4 · Answer 1 · answered May 09 '16 at 08:17

okey as you suggested you want to just blink your TextView, here what you can do.

create on folder under res called "anim", now create one xml file under that say

blink.xml and copy this code in it.

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<alpha
     android:fromAlpha="0.0"
     android:toAlpha="1.0"
     android:duration="1000" 
     android:repeatMode="reverse"
     android:repeatCount="infinite" /> 
</set>

Now in your Java class just apply this animation to your TextView

Animation anim = AnimationUtils.loadAnimation(getActivity(),
                    R.anim.blink);
yourtextview.startAnimation(anim);

Done.

score 3 · Answer 2 · edited May 09 '16 at 08:22

Instead of blocking thread using Thread.sleep(1000) you can use handler post delayed and after 1 second and make it visible and post another one to make it disappear .

new Handler().postDelayed(new Runnable() {
    @Override
    public void run() {
        /* Make it visible here. */
        button.setVisibility(View.VISIBLE);

        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
                /* Make it disappear here. */
                button.setVisibility(View.GONE);
            }
        }, 1000);      
    }
}, 1000);

score 3 · Answer 3 · edited May 09 '16 at 09:07

This simple code can help you blink your textview:

final String text = yourTextView.getText().toString();
TimerTask timerTask = new TimerTask() {
    @Override
    public void run() {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                if (yourTextView.getText().length() == 0) {
                    yourTextView.setText(text);
                } else {
                    yourTextView.setText("");
                }
            }
        });
    }
};
Timer timer = new Timer();
timer.scheduleAtFixedRate(timerTask,1000,1000);

How to make text on button appear and disappear continualy

3 Answers3