package nodomain.freeyourgadget.gadgetbridge.activities; import android.support.annotation.Nullable; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; /** * Abstract base class for fragments. Provides hooks that are called when * the fragment is made visible and invisible in the activity. also allows * the fragment to define the title to be shown in the activity. * * @see AbstractGBFragmentActivity */ public abstract class AbstractGBFragment extends Fragment { private boolean mVisibleInactivity; /** * Called when this fragment has been fully scrolled into the activity. * * @see #isVisibleInActivity() * @see #onMadeInvisibleInActivity() */ protected void onMadeVisibleInActivity() { updateActivityTitle(); } /** * Called when this fragment has been scrolled out of the activity. * * @see #isVisibleInActivity() * @see #onMadeVisibleInActivity() */ protected void onMadeInvisibleInActivity() { mVisibleInactivity = false; } /** * Returns true if this fragment is currently visible in the hosting * activity, not taking into account whether the screen is enabled at all. */ public boolean isVisibleInActivity() { return mVisibleInactivity; } protected void updateActivityTitle() { FragmentActivity activity = getActivity(); if (activity != null && !activity.isFinishing() && !activity.isDestroyed()) { if (getTitle() != null) { activity.setTitle(getTitle()); } } } @Nullable protected abstract CharSequence getTitle(); /** * Internal * * @hide */ public void onMadeVisibleInActivityInternal() { mVisibleInactivity = true; if (isVisible()) { onMadeVisibleInActivity(); } } }