1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.example.android.supportv7.widget; 18 19 import android.content.res.Configuration; 20 import android.content.res.Resources; 21 import android.content.res.TypedArray; 22 import android.os.Bundle; 23 import android.view.MenuItem; 24 import android.view.View; 25 import android.view.ViewTreeObserver; 26 import android.widget.AdapterView; 27 import android.widget.ArrayAdapter; 28 import android.widget.FrameLayout; 29 import android.widget.ListView; 30 import android.widget.TextView; 31 32 import androidx.appcompat.app.ActionBarDrawerToggle; 33 import androidx.appcompat.app.AppCompatActivity; 34 import androidx.appcompat.widget.Toolbar; 35 import androidx.core.content.ContextCompat; 36 import androidx.core.view.GravityCompat; 37 import androidx.drawerlayout.widget.DrawerLayout; 38 39 import com.example.android.supportv7.R; 40 import com.example.android.supportv7.Shakespeare; 41 42 /** 43 * This example illustrates a common usage of the DrawerLayout widget combined with Toolbar 44 * in the Android support library that respect the 45 * <a href="https://www.google.com/design/spec/patterns/navigation-drawer.html">Material design 46 * guidelines</a> for the drawer component. 47 * 48 * 49 * <p>A DrawerLayout should be positioned at the top of your view hierarchy, placing it 50 * below the action bar but above your content views. The primary content should match_parent 51 * in both dimensions. Each drawer should define a reasonable width and match_parent for height. 52 * Drawer views should be positioned after the content view in your layout to preserve proper 53 * ordering.</p> 54 * 55 * <p>When a navigation (left) drawer is present, the host activity should detect presses of 56 * the action bar's Up affordance as a signal to open and close the navigation drawer. 57 * Items within the drawer should fall into one of two categories.</p> 58 * 59 * <ul> 60 * <li><strong>View switches</strong>. A view switch follows the same basic policies as 61 * list or tab navigation in that a view switch does not create navigation history. 62 * This pattern should only be used at the root activity of a task, leaving some form 63 * of Up navigation active for activities further down the navigation hierarchy.</li> 64 * <li><strong>Selective Up</strong>. The drawer allows the user to choose an alternate 65 * parent for Up navigation. This allows a user to jump across an app's navigation 66 * hierarchy at will. The application should treat this as it treats Up navigation from 67 * a different task, replacing the current task stack using TaskStackBuilder or similar. 68 * This is the only form of navigation drawer that should be used outside of the root 69 * activity of a task.</li> 70 * </ul> 71 * 72 * <p>Right side drawers should be used for actions, not navigation. This follows the pattern 73 * established by the Action Bar that navigation should be to the left and actions to the right. 74 * An action should be an operation performed on the current contents of the window, 75 * for example enabling or disabling a data overlay on top of the current content.</p> 76 * 77 * <p>When the drawer is open, it is above the application toolbar. On Lollipop versions of the 78 * platform and above the drawer spans the full height of the screen, including behind the system 79 * status bar.</p> 80 */ 81 public class DrawerLayoutActivity extends AppCompatActivity { 82 private DrawerLayout mDrawerLayout; 83 private ListView mStartDrawer; 84 private FrameLayout mEndDrawer; 85 private TextView mContent; 86 87 private ActionBarDrawerToggle mDrawerToggle; 88 private Toolbar mToolbar; 89 90 @Override 91 protected void onCreate(Bundle savedInstanceState) { 92 super.onCreate(savedInstanceState); 93 94 setContentView(R.layout.drawer_layout); 95 96 mDrawerLayout = findViewById(R.id.drawer_layout); 97 mStartDrawer = findViewById(R.id.start_drawer); 98 mEndDrawer = findViewById(R.id.end_drawer); 99 mContent = findViewById(R.id.content_text); 100 101 mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START); 102 mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow_end, GravityCompat.END); 103 104 // The drawer title must be set in order to announce state changes when 105 // accessibility is turned on. This is typically a simple description, 106 // e.g. "Navigation". 107 mDrawerLayout.setDrawerTitle(GravityCompat.START, getString(R.string.drawer_title)); 108 109 mStartDrawer.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, 110 Shakespeare.TITLES)); 111 mStartDrawer.setOnItemClickListener(new DrawerItemClickListener()); 112 113 // Find the toolbar in our layout and set it as the support action bar on the activity. 114 // This is required to have the drawer slide "over" the toolbar. 115 mToolbar = findViewById(R.id.toolbar); 116 mToolbar.setTitle(R.string.drawer_title); 117 setSupportActionBar(mToolbar); 118 119 getSupportActionBar().setDisplayHomeAsUpEnabled(true); 120 getSupportActionBar().setDisplayShowHomeEnabled(false); 121 122 // ActionBarDrawerToggle provides convenient helpers for tying together the 123 // prescribed interactions between a top-level sliding drawer and the action bar. 124 // Note that, as the Javadocs of ActionBarDrawerToggle constructors say, we are 125 // *not* using a constructor that gets a Toolbar since we're setting our toolbar 126 // dynamically at runtime. Furthermore, as the drawer is sliding over the toolbar, 127 // we are suppressing the morphing animation from hamburger to back arrow by 128 // calling super.onDrawerSlide with slideOffset=0.0f. In case your app only has 129 // top-level pages and doesn't need back arrow visuals at all, you can set up 130 // your activity theme to have attribute named "drawerArrowStyle" that points 131 // to an extension of Widget.AppCompat.DrawerArrowToggle that has its "spinBars" 132 // attribute set to false. 133 mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout, 134 R.string.drawer_open, R.string.drawer_close) { 135 @Override 136 public void onDrawerOpened(View drawerView) { 137 super.onDrawerOpened(drawerView); 138 super.onDrawerSlide(drawerView, 0.0f); 139 } 140 141 @Override 142 public void onDrawerSlide(View drawerView, float slideOffset) { 143 super.onDrawerSlide(drawerView, 0.0f); 144 } 145 }; 146 147 mDrawerLayout.addDrawerListener(mDrawerToggle); 148 149 // Configure the background color fill of the system status bar (on supported platform 150 // versions) and the toolbar itself. We're using the same color, and android:statusBar 151 // from the theme makes the status bar slightly darker. 152 final int metalBlueColor = ContextCompat.getColor(this, R.color.drawer_sample_metal_blue); 153 mDrawerLayout.setStatusBarBackgroundColor(metalBlueColor); 154 mToolbar.setBackgroundColor(metalBlueColor); 155 156 // Register a pre-draw listener to get the initial width of the DrawerLayout so 157 // that we can determine the width of the drawer based on the Material spec at 158 // https://www.google.com/design/spec/patterns/navigation-drawer.html#navigation-drawer-specs 159 mDrawerLayout.getViewTreeObserver().addOnPreDrawListener( 160 new ViewTreeObserver.OnPreDrawListener() { 161 @Override 162 public boolean onPreDraw() { 163 // What is the width of the entire DrawerLayout? 164 final int drawerLayoutWidth = mDrawerLayout.getWidth(); 165 166 // What is the action bar size? 167 final Resources.Theme theme = mDrawerLayout.getContext().getTheme(); 168 final TypedArray a = theme.obtainStyledAttributes( 169 new int[] { androidx.appcompat.R.attr.actionBarSize }); 170 final int actionBarSize = a.getDimensionPixelSize(0, 0); 171 if (a != null) { 172 a.recycle(); 173 } 174 175 // Compute the width of the drawer and set it on the layout params. 176 final int idealDrawerWidth = 5 * actionBarSize; 177 final int maxDrawerWidth = Math.max(0, drawerLayoutWidth - actionBarSize); 178 final int drawerWidth = Math.min(idealDrawerWidth, maxDrawerWidth); 179 180 final DrawerLayout.LayoutParams startDrawerLp = 181 (DrawerLayout.LayoutParams) mStartDrawer.getLayoutParams(); 182 startDrawerLp.width = drawerWidth; 183 mStartDrawer.setLayoutParams(startDrawerLp); 184 185 final DrawerLayout.LayoutParams endDrawerLp = 186 (DrawerLayout.LayoutParams) mEndDrawer.getLayoutParams(); 187 endDrawerLp.width = drawerWidth; 188 mEndDrawer.setLayoutParams(endDrawerLp); 189 190 // Remove ourselves as the pre-draw listener since this is a one-time 191 // configuration. 192 mDrawerLayout.getViewTreeObserver().removeOnPreDrawListener(this); 193 return true; 194 } 195 }); 196 } 197 198 @Override 199 protected void onPostCreate(Bundle savedInstanceState) { 200 super.onPostCreate(savedInstanceState); 201 202 // Sync the toggle state after onRestoreInstanceState has occurred. 203 mDrawerToggle.syncState(); 204 } 205 206 @Override 207 public boolean onOptionsItemSelected(MenuItem item) { 208 /* 209 * The action bar home/up action should open or close the drawer. 210 * The drawer toggle will take care of this. 211 */ 212 if (mDrawerToggle.onOptionsItemSelected(item)) { 213 return true; 214 } 215 return super.onOptionsItemSelected(item); 216 } 217 218 @Override 219 public void onBackPressed() { 220 boolean hadOpenDrawer = false; 221 // Is the start drawer open? 222 if (mDrawerLayout.isDrawerOpen(mStartDrawer)) { 223 // Close it 224 mDrawerLayout.closeDrawer(mStartDrawer); 225 hadOpenDrawer = true; 226 } 227 // Is the end drawer open? 228 if (mDrawerLayout.isDrawerOpen(mEndDrawer)) { 229 // Close it 230 mDrawerLayout.closeDrawer(mEndDrawer); 231 hadOpenDrawer = true; 232 } 233 234 if (hadOpenDrawer) { 235 // If we had one or both drawers open, now that we've closed it / them, return. 236 return; 237 } 238 239 super.onBackPressed(); 240 } 241 242 @Override 243 public void onConfigurationChanged(Configuration newConfig) { 244 super.onConfigurationChanged(newConfig); 245 mDrawerToggle.onConfigurationChanged(newConfig); 246 } 247 248 /** 249 * This list item click listener implements very simple view switching by changing 250 * the primary content text. The drawer is closed when a selection is made. 251 */ 252 private class DrawerItemClickListener implements ListView.OnItemClickListener { 253 @Override 254 public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 255 mContent.setText(Shakespeare.DIALOGUE[position]); 256 mToolbar.setTitle(Shakespeare.TITLES[position]); 257 mDrawerLayout.closeDrawer(mStartDrawer); 258 } 259 } 260 } 261