Java tutorial
package de.lebenshilfe_muenster.uk_gebaerden_muensterland.activities; import android.app.Fragment; import android.app.FragmentTransaction; import android.content.Intent; import android.os.Bundle; import android.os.Parcelable; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.util.Log; import org.apache.commons.lang3.StringUtils; import org.apache.commons.lang3.Validate; import de.lebenshilfe_muenster.uk_gebaerden_muensterland.R; import de.lebenshilfe_muenster.uk_gebaerden_muensterland.sign_browser.video.SignVideoFragment; /** * Copyright (c) 2016 Matthias Tonhuser * <p/> * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * <p/> * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * <p/> * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ public class LevelOneActivity extends AppCompatActivity { public static final String FRAGMENT_TO_SHOW = "fragment_to_show"; public static final String EXTRA = "extra"; private static final String TAG = LevelOneActivity.class.getSimpleName(); private static final String SIGN_VIDEO_TAG = "sign_video_tag"; @Override protected void onCreate(Bundle savedInstanceState) { Log.d(TAG, "onCreate()"); super.onCreate(savedInstanceState); setupView(); setupVideoFragment(); } private void setupView() { setContentView(R.layout.level_one_activity); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); Validate.notNull(getSupportActionBar(), "SupportActionBar is null."); getSupportActionBar().setDisplayHomeAsUpEnabled(true); getSupportActionBar().setTitle(R.string.sign_viewer); } private void setupVideoFragment() { final Intent intent = getIntent(); final Bundle bundle = intent.getBundleExtra(EXTRA); Validate.notNull(bundle, "The bundle supplied to the activity is null."); final String fragmentToShow = bundle.getString(FRAGMENT_TO_SHOW, StringUtils.EMPTY); if (SignVideoFragment.class.getSimpleName().equals(fragmentToShow)) { final Parcelable sign = bundle.getParcelable(SignVideoFragment.SIGN_TO_SHOW); SignVideoFragment signVideoFragment = new SignVideoFragment(); final Bundle args = new Bundle(); args.putParcelable(SignVideoFragment.SIGN_TO_SHOW, sign); signVideoFragment.setArguments(args); setFragment(signVideoFragment, SIGN_VIDEO_TAG); } else { throw new IllegalArgumentException("Cannot show the fragment with name: " + fragmentToShow); } } private void setFragment(Fragment fragment, String fragmentTag) { Log.d(TAG, "setFragment: " + fragmentTag); final FragmentTransaction transaction = getFragmentManager().beginTransaction(); transaction.replace(R.id.content_frame_level_one, fragment, fragmentTag); transaction.addToBackStack(null); transaction.commit(); } @Override public void onBackPressed() { Log.d(TAG, "onBackPressed() " + this.hashCode()); finish(); } }