BriarFragmentActivity.java

package org.briarproject.android;

import android.support.annotation.AnimRes;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AlertDialog;

import org.briarproject.R;
import org.briarproject.android.contact.ContactListFragment;
import org.briarproject.android.forum.ForumListFragment;
import org.briarproject.android.fragment.BaseFragment;

/**
 * This class should be extended by classes that wish to utilise fragments in
 * Briar, it encapsulates all fragment related code.
 */
public abstract class BriarFragmentActivity extends BriarActivity {

	private void updateToolbarTitle(String fragmentTag) {
		ActionBar actionBar = getSupportActionBar();
		if (actionBar == null)
			return;

		if (fragmentTag.equals(ContactListFragment.TAG)) {
			actionBar.setTitle(R.string.contacts_toolbar_header);
		} else if (fragmentTag.equals(ForumListFragment.TAG)) {
			actionBar.setTitle(R.string.forums_toolbar_header);
		}
	}

	protected void clearBackStack() {
		getSupportFragmentManager()
				.popBackStackImmediate(
						null,
						FragmentManager.POP_BACK_STACK_INCLUSIVE
				);
	}

	@Override
	public void onBackPressed() {
		if (this instanceof NavDrawerActivity &&
				getSupportFragmentManager().getBackStackEntryCount() == 0 &&
				getSupportFragmentManager()
						.findFragmentByTag(ContactListFragment.TAG) == null) {
			/*
			This Makes sure that the first fragment (ContactListFragment) the
			user sees is the same as the last fragment the user sees before
			exiting. This models the typical Google navigation behaviour such
			as in Gmail/Inbox.
			 */
			startFragment(activityComponent.newContactListFragment());

		} else {
			super.onBackPressed();
		}
	}

	protected void startFragment(BaseFragment fragment) {
		if (getSupportFragmentManager().getBackStackEntryCount() == 0)
			this.startFragment(fragment, false);
		else
			this.startFragment(fragment, true);
	}

	protected void showMessageDialog(int titleStringId, int msgStringId) {
		// TODO replace with custom dialog fragment ?
		AlertDialog.Builder builder = new AlertDialog.Builder(this,
				R.style.BriarDialogTheme);
		builder.setTitle(titleStringId);
		builder.setMessage(msgStringId);
		builder.setPositiveButton(R.string.dialog_button_ok, null);
		AlertDialog dialog = builder.create();
		dialog.show();
	}

	protected void startFragment(BaseFragment fragment,
			boolean isAddedToBackStack) {
		this.startFragment(fragment, 0, 0, isAddedToBackStack);
	}

	protected void startFragment(BaseFragment fragment,
			@AnimRes int inAnimation, @AnimRes int outAnimation,
			boolean isAddedToBackStack) {
		FragmentTransaction trans =
				getSupportFragmentManager().beginTransaction();
		if (inAnimation != 0 && outAnimation != 0) {
			trans.setCustomAnimations(inAnimation, 0, 0, outAnimation);
		}
		trans.replace(R.id.content_fragment, fragment, fragment.getUniqueTag());
		if (isAddedToBackStack) {
			trans.addToBackStack(fragment.getUniqueTag());
		}
		trans.commit();
		updateToolbarTitle(fragment.getUniqueTag());
	}

}