Question

Using the following code:

public class Panel extends SurfaceView  {
    // ......
    // in one of the methods I want to call  
    Display display = getWindowManager().getDefaultDisplay();
    // ......
}

The problem is with the getWindowManager() method, I guess this method can be called only in activity, but I am not in the activity I am in my custom method called panel. How can I get the DisplayMetrics in my custom component ?

Answer 1

To get the display metrics you have to do this.

DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);

Then you can do this.

Panel p = (Panel) findViewById(R.id.panel);
p.setDisplayMetrics(displayMetrics);

And have access to it in your custom view.

public class Panel extends SurfaceView {
    private DisplayMetrics mDisplayMetrics;

    public void setDisplayMetrics(DisplayMetrics displayMetrics) {
        mDisplayMetrics = displayMetrics;
    }

    void myFunction() {
        // do something with display metrics
    }
}