content: package com.allenxuan.xuanyihuang.xuanimageviewproject;
  
  import android.content.Intent;
  import android.os.Bundle;
  import android.support.design.widget.FloatingActionButton;
  import android.support.design.widget.Snackbar;
  import android.view.View;
  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.view.Menu;
  import android.view.MenuItem;
  
  public class SingleImageLaunchActivity extends AppCompatActivity
          implements NavigationView.OnNavigationItemSelectedListener {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_single_image_launch);
          Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
          setSupportActionBar(toolbar);
  
          DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
          ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                  this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
          drawer.setDrawerListener(toggle);
          toggle.syncState();
  
          NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
          navigationView.setNavigationItemSelectedListener(this);
      }
  
      @Override
      public void onBackPressed() {
          DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
          if (drawer.isDrawerOpen(GravityCompat.START)) {
              drawer.closeDrawer(GravityCompat.START);
          } else {
              super.onBackPressed();
          }
      }
  
      @Override
      public boolean onCreateOptionsMenu(Menu menu) {
          // Inflate the menu; this adds items to the action bar if it is present.
          getMenuInflater().inflate(R.menu.single_image_launch, menu);
          return true;
      }
  
      @Override
      public boolean onOptionsItemSelected(MenuItem item) {
          // Handle action bar item clicks here. The action bar will
          // automatically handle clicks on the Home/Up button, so long
          // as you specify a parent activity in AndroidManifest.xml.
          int id = item.getItemId();
  
          //noinspection SimplifiableIfStatement
          if (id == R.id.action_settings) {
              return true;
          }
  
          return super.onOptionsItemSelected(item);
      }
  
      @SuppressWarnings("StatementWithEmptyBody")
      @Override
      public boolean onNavigationItemSelected(MenuItem item) {
          // Handle navigation view item clicks here.
          int id = item.getItemId();
  
          switch (id){
              case R.id.image_pager:
                  startActivity(new Intent(this, ImagePagerActivity.class));
                  break;
              case R.id.with_glide:
                  startActivity(new Intent(this, WithGlideActivity.class));
                  break;
              case R.id.with_picasso:
                  startActivity(new Intent(this, WithPicassoActivity.class));
                  break;
          }
  
          DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
          drawer.closeDrawer(GravityCompat.START);
          return true;
      }
  }
  