/*
* Copyright (C) 2015 The Android Open Source Project
*
* 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.example.android.supportv7.widget;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.support.v4.content.ContextCompat;
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.MenuItem;
import android.view.View;
import android.view.ViewTreeObserver;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.FrameLayout;
import android.widget.ListView;
import android.widget.TextView;
import com.example.android.supportv7.R;
import com.example.android.supportv7.Shakespeare;
/**
* This example illustrates a common usage of the DrawerLayout widget combined with Toolbar
* in the Android support library that respect the
* <a href="https://www.google.com/design/spec/patterns/navigation-drawer.html">Material design
* guidelines</a> for the drawer component.
*
*
* <p>A DrawerLayout should be positioned at the top of your view hierarchy, placing it
* below the action bar but above your content views. The primary content should match_parent
* in both dimensions. Each drawer should define a reasonable width and match_parent for height.
* Drawer views should be positioned after the content view in your layout to preserve proper
* ordering.</p>
*
* <p>When a navigation (left) drawer is present, the host activity should detect presses of
* the action bar's Up affordance as a signal to open and close the navigation drawer.
* Items within the drawer should fall into one of two categories.</p>
*
* <ul>
* <li><strong>View switches</strong>. A view switch follows the same basic policies as
* list or tab navigation in that a view switch does not create navigation history.
* This pattern should only be used at the root activity of a task, leaving some form
* of Up navigation active for activities further down the navigation hierarchy.</li>
* <li><strong>Selective Up</strong>. The drawer allows the user to choose an alternate
* parent for Up navigation. This allows a user to jump across an app's navigation
* hierarchy at will. The application should treat this as it treats Up navigation from
* a different task, replacing the current task stack using TaskStackBuilder or similar.
* This is the only form of navigation drawer that should be used outside of the root
* activity of a task.</li>
* </ul>
*
* <p>Right side drawers should be used for actions, not navigation. This follows the pattern
* established by the Action Bar that navigation should be to the left and actions to the right.
* An action should be an operation performed on the current contents of the window,
* for example enabling or disabling a data overlay on top of the current content.</p>
*
* <p>When the drawer is open, it is above the application toolbar. On Lollipop versions of the
* platform and above the drawer spans the full height of the screen, including behind the system
* status bar.</p>
*/
public class DrawerLayoutActivity extends AppCompatActivity {
private DrawerLayout mDrawerLayout;
private ListView mStartDrawer;
private FrameLayout mEndDrawer;
private TextView mContent;
private ActionBarDrawerToggle mDrawerToggle;
private Toolbar mToolbar;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.drawer_layout);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mStartDrawer = (ListView) findViewById(R.id.start_drawer);
mEndDrawer = (FrameLayout) findViewById(R.id.end_drawer);
mContent = (TextView) findViewById(R.id.content_text);
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow, GravityCompat.START);
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow_end, GravityCompat.END);
// The drawer title must be set in order to announce state changes when
// accessibility is turned on. This is typically a simple description,
// e.g. "Navigation".
mDrawerLayout.setDrawerTitle(GravityCompat.START, getString(R.string.drawer_title));
mStartDrawer.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,
Shakespeare.TITLES));
mStartDrawer.setOnItemClickListener(new DrawerItemClickListener());
// Find the toolbar in our layout and set it as the support action bar on the activity.
// This is required to have the drawer slide "over" the toolbar.
mToolbar = (Toolbar) findViewById(R.id.toolbar);
mToolbar.setTitle(R.string.drawer_title);
setSupportActionBar(mToolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayShowHomeEnabled(false);
// ActionBarDrawerToggle provides convenient helpers for tying together the
// prescribed interactions between a top-level sliding drawer and the action bar.
// Note that, as the Javadocs of ActionBarDrawerToggle constructors say, we are
// *not* using a constructor that gets a Toolbar since we're setting our toolbar
// dynamically at runtime. Furthermore, as the drawer is sliding over the toolbar,
// we are suppressing the morphing animation from hamburger to back arrow by
// calling super.onDrawerSlide with slideOffset=0.0f. In case your app only has
// top-level pages and doesn't need back arrow visuals at all, you can set up
// your activity theme to have attribute named "drawerArrowStyle" that points
// to an extension of Widget.AppCompat.DrawerArrowToggle that has its "spinBars"
// attribute set to false.
mDrawerToggle = new ActionBarDrawerToggle(this, mDrawerLayout,
R.string.drawer_open, R.string.drawer_close) {
@Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
super.onDrawerSlide(drawerView, 0.0f);
}
@Override
public void onDrawerSlide(View drawerView, float slideOffset) {
super.onDrawerSlide(drawerView, 0.0f);
}
};
mDrawerLayout.addDrawerListener(mDrawerToggle);
// Configure the background color fill of the system status bar (on supported platform
// versions) and the toolbar itself. We're using the same color, and android:statusBar
// from the theme makes the status bar slightly darker.
final int metalBlueColor = ContextCompat.getColor(this, R.color.drawer_sample_metal_blue);
mDrawerLayout.setStatusBarBackgroundColor(metalBlueColor);
mToolbar.setBackgroundColor(metalBlueColor);
// Register a pre-draw listener to get the initial width of the DrawerLayout so
// that we can determine the width of the drawer based on the Material spec at
// https://www.google.com/design/spec/patterns/navigation-drawer.html#navigation-drawer-specs
mDrawerLayout.getViewTreeObserver().addOnPreDrawListener(
new ViewTreeObserver.OnPreDrawListener() {
@Override
public boolean onPreDraw() {
// What is the width of the entire DrawerLayout?
final int drawerLayoutWidth = mDrawerLayout.getWidth();
// What is the action bar size?
final Resources.Theme theme = mDrawerLayout.getContext().getTheme();
final TypedArray a = theme.obtainStyledAttributes(
new int[] { android.support.v7.appcompat.R.attr.actionBarSize });
final int actionBarSize = a.getDimensionPixelSize(0, 0);
if (a != null) {
a.recycle();
}
// Compute the width of the drawer and set it on the layout params.
final int idealDrawerWidth = 5 * actionBarSize;
final int maxDrawerWidth = Math.max(0, drawerLayoutWidth - actionBarSize);
final int drawerWidth = Math.min(idealDrawerWidth, maxDrawerWidth);
final DrawerLayout.LayoutParams startDrawerLp =
(DrawerLayout.LayoutParams) mStartDrawer.getLayoutParams();
startDrawerLp.width = drawerWidth;
mStartDrawer.setLayoutParams(startDrawerLp);
final DrawerLayout.LayoutParams endDrawerLp =
(DrawerLayout.LayoutParams) mEndDrawer.getLayoutParams();
endDrawerLp.width = drawerWidth;
mEndDrawer.setLayoutParams(endDrawerLp);
// Remove ourselves as the pre-draw listener since this is a one-time
// configuration.
mDrawerLayout.getViewTreeObserver().removeOnPreDrawListener(this);
return true;
}
});
}
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mDrawerToggle.syncState();
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
/*
* The action bar home/up action should open or close the drawer.
* The drawer toggle will take care of this.
*/
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
return super.onOptionsItemSelected(item);
}
@Override
public void onBackPressed() {
boolean hadOpenDrawer = false;
// Is the start drawer open?
if (mDrawerLayout.isDrawerOpen(mStartDrawer)) {
// Close it
mDrawerLayout.closeDrawer(mStartDrawer);
hadOpenDrawer = true;
}
// Is the end drawer open?
if (mDrawerLayout.isDrawerOpen(mEndDrawer)) {
// Close it
mDrawerLayout.closeDrawer(mEndDrawer);
hadOpenDrawer = true;
}
if (hadOpenDrawer) {
// If we had one or both drawers open, now that we've closed it / them, return.
return;
}
super.onBackPressed();
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
mDrawerToggle.onConfigurationChanged(newConfig);
}
/**
* This list item click listener implements very simple view switching by changing
* the primary content text. The drawer is closed when a selection is made.
*/
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
mContent.setText(Shakespeare.DIALOGUE[position]);
mToolbar.setTitle(Shakespeare.TITLES[position]);
mDrawerLayout.closeDrawer(mStartDrawer);
}
}
}