getWindowManager().getDefaultDisplay().getMetrics(metrics) not working properly

Question

I'm using this code, to get screen size

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.some_layout);
    //more stuff
    setTextSize();
}

private void setTextSize() {
    DisplayMetrics metrics = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(metrics);
    int width = metrics.widthPixels;
    //more code
    sometextview.setTextSize(TypedValue.COMPLEX_UNIT_PX, width/10); //example only
}

As it turns out, in rare cases this doesn't work. I'm setting some text size, and sometimes it doesn't resize text at all. I think it only happens whenever I haven't open application in a while, so it's very hard to debug it. Only idea I have is, that this is asking for screen size before application even knows it (it's the first activity). How can I solve this? This is the only method for getting screen resolution that I know that supports all APIs.

Try [this](http://stackoverflow.com/questions/8833825/get-window-size-on-android) (see the first answer) — Alex Timonin, Dec 02 '12 at 09:51
It works the same, problem is it might be a few days before the "bug" happens. — Bojan Kogoj, Dec 02 '12 at 10:15

score 0 · Answer 1 · answered Dec 02 '12 at 13:17

You need to use ViewTreeObserver for this specific Textview.

Some code snippet.

ViewTreeObserver vto = myTextView.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

            @Override
            public void onGlobalLayout() {
                setTextSize();

            }
        });

The only thing you should be careful of is that this would be called repeatedly every time view changes, so you need to keep a dirty flag to track changes.

getWindowManager().getDefaultDisplay().getMetrics(metrics) not working properly

1 Answers1