FullScreenAppCompatActivity.java

package de.blau.android.util;

import android.annotation.SuppressLint;
import android.os.Build;
import android.os.Handler;
import android.util.Log;
import android.view.KeyCharacterMap;
import android.view.KeyEvent;
import android.view.View;
import de.blau.android.R;
import de.blau.android.prefs.Preferences;

/**
 * Handle determining if we are on a system with soft navigation buttons and switch to full screen mode
 * @author simon
 *
 */
public abstract class FullScreenAppCompatActivity extends BugFixedAppCompatActivity {

	private static final String DEBUG_TAG = FullScreenAppCompatActivity.class.getSimpleName();
	private boolean fullScreen = false;
	private final Handler handler =  new Handler();

	@SuppressLint("NewApi")
	@Override
	protected void onResume() {
		super.onResume();
		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
			View decorView = getWindow().getDecorView();
			decorView.setOnSystemUiVisibilityChangeListener
			(new View.OnSystemUiVisibilityChangeListener() {
				@Override
				public void onSystemUiVisibilityChange(int visibility) {
					Log.d(DEBUG_TAG,"onSystemUiVisibilityChange " + Integer.toHexString(visibility));
					if ((visibility & View.SYSTEM_UI_FLAG_HIDE_NAVIGATION) == 0) {
						if (fullScreen) {
							synchronized (handler) {
								handler.removeCallbacks(navHider);
								handler.postDelayed(navHider, 2000);
							}
						}
					} else {
						// no UI changes for now
					}
				}
			});
		}
		if (fullScreen) {
			synchronized (handler) {
				handler.removeCallbacks(navHider);
				//FIXME there seems to be a timing issue or similar that causes the nav bar to re-appear just after it has been hidden by
				//onWindowFocusChanged, this makes sure that the bar is re-hidden. The 1.5 seconds seems to work.
				handler.postDelayed(navHider, 1500);
			}
		}
	}

	@Override
	public void onWindowFocusChanged(boolean hasFocus) {
		super.onWindowFocusChanged(hasFocus);	
		if (hasFocus) {
			Log.d(DEBUG_TAG,"onWindowFocusChanged");
			hideNavBar();
		}	
	}

	private Runnable navHider = new Runnable() {
		@Override public void run() {
			hideNavBar();
		}
	};

	/**
	 * Return true if we are in full screen mode
	 * @return true if in full screen mode
	 */
	public boolean isFullScreen() {
		return fullScreen;
	}

	/**
	 * Turn off a soft button navigation button, note this only works if the main view of the app actually has focus
	 */
	@SuppressLint("NewApi")
	private void hideNavBar() {
		View view = getWindow().getDecorView();
		if (view != null && fullScreen && Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
			Log.d(DEBUG_TAG,"hiding nav bar");
			view.setSystemUiVisibility(
					View.SYSTEM_UI_FLAG_LAYOUT_STABLE
					| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
					| View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
					| (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT ? View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY : View.SYSTEM_UI_FLAG_IMMERSIVE)
					);
		}
	}

	/**
	 * This is likely not all too reliable
	 * @return true if we should use  the full screen layout
	 */
	protected boolean useFullScreen(Preferences prefs) {
		fullScreen = false;
		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
			String fullscreenPref = prefs.getFullscreenMode();	
			if (fullscreenPref.equals(getString(R.string.full_screen_auto))) {
				fullScreen = !KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_BACK) && !KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_HOME);
				Log.d(DEBUG_TAG,"full screen auto " + fullScreen  +  " KEYCODE_BACK " + KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_BACK) 
				+ " KEYCODE_HOME " + KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_HOME));
			} else if (fullscreenPref.equals(getString(R.string.full_screen_never))) {
				fullScreen = false;
				Log.d(DEBUG_TAG,"full screen never");
			} else if (fullscreenPref.equals(getString(R.string.full_screen_force))) {
				fullScreen = true;
				Log.d(DEBUG_TAG,"full screen force");
			} else if (fullscreenPref.equals(getString(R.string.full_screen_no_statusbar))) {
				fullScreen = true;
				Log.d(DEBUG_TAG,"full screen no statusbar");
				return false; // ugly hack
			}
		} 
		return fullScreen;
	}
}