Java tutorial
/* * Copyright (C) 2017 Tnno Wu * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.tnnowu.android.googlenavigation; import android.app.ActivityOptions; import android.app.FragmentManager; import android.content.Intent; import android.content.res.Configuration; import android.os.Bundle; import android.support.design.widget.NavigationView; import android.support.v4.view.GravityCompat; import android.support.v4.widget.DrawerLayout; import android.support.v7.app.ActionBarDrawerToggle; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.MenuItem; import android.view.View; /** * Created by Tnno Wu on 2017/5/6. */ public class BaseActivity extends AppCompatActivity { private static final String TAG = "BaseActivity"; private Toolbar mToolbar; private ActionBarDrawerToggle mDrawerToggle; private DrawerLayout mDrawerLayout; private boolean mToolbarInitialized; private int mItemToOpenWhenDrawerCloses = -1; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); Log.d(TAG, "Activity onCreate"); } @Override protected void onStart() { super.onStart(); if (!mToolbarInitialized) { throw new IllegalStateException( "You must run super.initializeToolbar at " + "the end of your onCreate method"); } } @Override public void onResume() { super.onResume(); // Whenever the fragment back stack changes, we may need to update the // action bar toggle: only top level screens show the hamburger-like icon, inner // screens - either Activities or fragments - show the "Up" icon instead. getFragmentManager().addOnBackStackChangedListener(backStackChangedListener); } @Override public void onPause() { super.onPause(); getFragmentManager().removeOnBackStackChangedListener(backStackChangedListener); } @Override protected void onPostCreate(Bundle savedInstanceState) { super.onPostCreate(savedInstanceState); if (mDrawerToggle != null) { mDrawerToggle.syncState(); } } @Override public void onConfigurationChanged(Configuration newConfig) { super.onConfigurationChanged(newConfig); if (mDrawerToggle != null) { mDrawerToggle.onConfigurationChanged(newConfig); } } @Override public boolean onOptionsItemSelected(MenuItem item) { if (mDrawerToggle != null && mDrawerToggle.onOptionsItemSelected(item)) { return true; } // If not handled by drawerToggle, home needs to be handled by returning to previous if (item != null && item.getItemId() == android.R.id.home) { onBackPressed(); return true; } return super.onOptionsItemSelected(item); } @Override public void onBackPressed() { // If the drawer is open, back will close it if (mDrawerLayout != null && mDrawerLayout.isDrawerOpen(GravityCompat.START)) { mDrawerLayout.closeDrawers(); return; } // Otherwise, it may return to the previous fragment stack FragmentManager fragmentManager = getFragmentManager(); if (fragmentManager.getBackStackEntryCount() > 0) { fragmentManager.popBackStack(); } else { // Lastly, it will rely on the system behavior for back super.onBackPressed(); } } private final FragmentManager.OnBackStackChangedListener backStackChangedListener = new FragmentManager.OnBackStackChangedListener() { @Override public void onBackStackChanged() { updateDrawerToggle(); } }; protected void updateDrawerToggle() { if (mDrawerToggle == null) { return; } boolean isRoot = getFragmentManager().getBackStackEntryCount() == 0; mDrawerToggle.setDrawerIndicatorEnabled(isRoot); if (getSupportActionBar() != null) { getSupportActionBar().setDisplayShowHomeEnabled(!isRoot); getSupportActionBar().setDisplayHomeAsUpEnabled(!isRoot); getSupportActionBar().setHomeButtonEnabled(!isRoot); } if (isRoot) { mDrawerToggle.syncState(); } } protected void initializeToolbar() { mToolbar = (Toolbar) findViewById(R.id.toolbar); if (mToolbar == null) { throw new IllegalStateException("Layout is required to include a Toolbar with id " + "'toolbar'"); } // mToolbar.inflateMenu(R.menu.main); mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout); if (mDrawerLayout != null) { NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view); if (navigationView == null) { throw new IllegalStateException("Layout requires a NavigationView " + "with id 'nav_view'"); } // Create an ActionBarDrawerToggle that will handle opening/closing of the drawer: mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout, mToolbar, R.string.open_content_drawer, R.string.close_content_drawer); mDrawerLayout.setDrawerListener(drawerListener); populateDrawerItems(navigationView); setSupportActionBar(mToolbar); updateDrawerToggle(); } else { setSupportActionBar(mToolbar); } mToolbarInitialized = true; } private final DrawerLayout.DrawerListener drawerListener = new DrawerLayout.DrawerListener() { @Override public void onDrawerSlide(View drawerView, float slideOffset) { if (mDrawerToggle != null) mDrawerToggle.onDrawerSlide(drawerView, slideOffset); } @Override public void onDrawerOpened(View drawerView) { if (mDrawerToggle != null) mDrawerToggle.onDrawerOpened(drawerView); if (getSupportActionBar() != null) getSupportActionBar().setTitle(R.string.app_name); } @Override public void onDrawerClosed(View drawerView) { if (mDrawerToggle != null) mDrawerToggle.onDrawerClosed(drawerView); if (mItemToOpenWhenDrawerCloses >= 0) { Bundle extras = ActivityOptions .makeCustomAnimation(BaseActivity.this, R.anim.fade_in, R.anim.fade_out).toBundle(); Class activityClass = null; switch (mItemToOpenWhenDrawerCloses) { case R.id.navigation_first: activityClass = FirstActivity.class; break; case R.id.navigation_second: activityClass = SecondActivity.class; break; case R.id.navigation_third: activityClass = ThirdActivity.class; break; } if (activityClass != null) { startActivity(new Intent(BaseActivity.this, activityClass), extras); finish(); } } } @Override public void onDrawerStateChanged(int newState) { if (mDrawerToggle != null) mDrawerToggle.onDrawerStateChanged(newState); } }; private void populateDrawerItems(NavigationView navigationView) { navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() { @Override public boolean onNavigationItemSelected(MenuItem menuItem) { menuItem.setChecked(true); mItemToOpenWhenDrawerCloses = menuItem.getItemId(); mDrawerLayout.closeDrawers(); return true; } }); if (FirstActivity.class.isAssignableFrom(getClass())) { navigationView.setCheckedItem(R.id.navigation_first); } else if (SecondActivity.class.isAssignableFrom(getClass())) { navigationView.setCheckedItem(R.id.navigation_second); } else if (ThirdActivity.class.isAssignableFrom(getClass())) { navigationView.setCheckedItem(R.id.navigation_third); } } }