car/src/main/java/androidx/car/drawer/CarDrawerController.java - platform/frameworks/support - Git at Google

 /*
  * Copyright (C) 2017 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 androidx.car.drawer;

 import android.content.Context;
 import android.content.res.Configuration;
 import android.os.Bundle;
 import android.view.Gravity;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.animation.AnimationUtils;
 import android.widget.ProgressBar;
 import android.widget.TextView;

 import androidx.annotation.AnimRes;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.ActionBarDrawerToggle;
 import androidx.appcompat.widget.Toolbar;
 import androidx.car.R;
 import androidx.car.widget.PagedListView;
 import androidx.drawerlayout.widget.DrawerLayout;
 import androidx.recyclerview.widget.RecyclerView;

 import java.util.ArrayDeque;

 /**
  * A controller that will handle the set up of the navigation drawer. It will hook up the
  * necessary buttons for up navigation, as well as expose methods to allow for a drill down
  * navigation.
  */
 public class CarDrawerController {
     /** An animation for when a user navigates into a submenu. */
     @AnimRes
     private static final int DRILL_DOWN_ANIM = R.anim.fade_in_trans_right_layout_anim;

     /** An animation for when a user navigates up (when the back button is pressed). */
     @AnimRes
     private static final int NAVIGATE_UP_ANIM = R.anim.fade_in_trans_left_layout_anim;

     /**
      * A representation of the hierarchy of navigation being displayed in the list. The ordering of
      * this stack is the order that the user has visited each level. When the user navigates up,
      * the adapters are popped from this list.
      */
     private final ArrayDeque<CarDrawerAdapter> mAdapterStack = new ArrayDeque<>();

     private final Context mContext;

     private final TextView mTitleView;
     private final DrawerLayout mDrawerLayout;
     private final ActionBarDrawerToggle mDrawerToggle;

     private final PagedListView mDrawerList;
     private final ProgressBar mProgressBar;

     /**
      * @deprecated Use {@link #CarDrawerController(DrawerLayout, ActionBarDrawerToggle)} instead.
      *             The {@code Toolbar} is no longer needed and will be ignored.
      */
     @Deprecated
     public CarDrawerController(@Nullable Toolbar toolbar, @NonNull DrawerLayout drawerLayout,
             @NonNull ActionBarDrawerToggle drawerToggle) {
         this(drawerLayout, drawerToggle);
     }

     /**
      * Creates a {@link CarDrawerController} that will control the navigation of the drawer given by
      * {@code drawerLayout}.
      *
      * <p>The given {@code drawerLayout} should either have a child View that is inflated from
      * {@code R.layout.car_drawer} or ensure that it three children that have the IDs found in that
      * layout.
      *
      * @param drawerLayout The top-level container for the window content that shows the
      *                     interactive drawer.
      * @param drawerToggle The {@link ActionBarDrawerToggle} that will open the drawer.
      */
     public CarDrawerController(@NonNull DrawerLayout drawerLayout,
             @NonNull ActionBarDrawerToggle drawerToggle) {
         mContext = drawerLayout.getContext();
         mDrawerToggle = drawerToggle;
         mDrawerLayout = drawerLayout;

         mTitleView = drawerLayout.findViewById(R.id.drawer_title);
         mDrawerList = drawerLayout.findViewById(R.id.drawer_list);
         mDrawerList.setMaxPages(PagedListView.ItemCap.UNLIMITED);
         mProgressBar = drawerLayout.findViewById(R.id.drawer_progress);

         drawerLayout.findViewById(R.id.drawer_back_button).setOnClickListener(v -> {
             if (!maybeHandleUpClick()) {
                 closeDrawer();
             }
         });

         setupDrawerToggling();
     }

     /**
      * Sets the {@link CarDrawerAdapter} that will function as the root adapter. The contents of
      * this root adapter are shown when the drawer is first opened. It is also the top-most level of
      * navigation in the drawer.
      *
      * @param rootAdapter The adapter that will act as the root. If this value is {@code null}, then
      *                    this method will do nothing.
      */
     public void setRootAdapter(@Nullable CarDrawerAdapter rootAdapter) {
         if (rootAdapter == null) {
             return;
         }

         // The root adapter is always the last item in the stack.
         if (!mAdapterStack.isEmpty()) {
             mAdapterStack.removeLast();
         }
         mAdapterStack.addLast(rootAdapter);
         setDisplayAdapter(rootAdapter);
     }

     /**
      * Switches to use the given {@link CarDrawerAdapter} as the one to supply the list to display
      * in the navigation drawer. The title will also be updated from the adapter.
      *
      * <p>This switch is treated as a navigation to the next level in the drawer. Navigation away
      * from this level will pop the given adapter off and surface contents of the previous adapter
      * that was set via this method. If no such adapter exists, then the root adapter set by
      * {@link #setRootAdapter(CarDrawerAdapter)} will be used instead.
      *
      * @param adapter Adapter for next level of content in the drawer.
      */
     public final void pushAdapter(CarDrawerAdapter adapter) {
         mAdapterStack.peek().setTitleChangeListener(null);
         mAdapterStack.push(adapter);
         setDisplayAdapter(adapter);
         runLayoutAnimation(DRILL_DOWN_ANIM);
     }

     /** Close the drawer. */
     public void closeDrawer() {
         if (mDrawerLayout.isDrawerOpen(Gravity.LEFT)) {
             mDrawerLayout.closeDrawer(Gravity.LEFT);
         }
     }

     /** Opens the drawer. */
     public void openDrawer() {
         if (!mDrawerLayout.isDrawerOpen(Gravity.LEFT)) {
             mDrawerLayout.openDrawer(Gravity.LEFT);
         }
     }

     /** Sets a listener to be notified of Drawer events. */
     public void addDrawerListener(@NonNull DrawerLayout.DrawerListener listener) {
         mDrawerLayout.addDrawerListener(listener);
     }

     /** Removes a listener to be notified of Drawer events. */
     public void removeDrawerListener(@NonNull DrawerLayout.DrawerListener listener) {
         mDrawerLayout.removeDrawerListener(listener);
     }

     /**
      * Sets whether the loading progress bar is displayed in the navigation drawer. If {@code true},
      * the progress bar is displayed and the navigation list is hidden and vice versa.
      */
     public void showLoadingProgressBar(boolean show) {
         mDrawerList.setVisibility(show ? View.INVISIBLE : View.VISIBLE);
         mProgressBar.setVisibility(show ? View.VISIBLE : View.GONE);
     }

     /** Scroll to given position in the list. */
     public void scrollToPosition(int position) {
         mDrawerList.getRecyclerView().smoothScrollToPosition(position);
     }

     /**
      * Retrieves the title from the given {@link CarDrawerAdapter} and set its as the title of this
      * controller's internal Toolbar.
      */
     private void setToolbarTitleFrom(CarDrawerAdapter adapter) {
         mTitleView.setText(adapter.getTitle());
         adapter.setTitleChangeListener(mTitleView::setText);
     }

     /**
      * Sets up the necessary listeners for {@link DrawerLayout} so that the navigation drawer
      * hierarchy is properly displayed.
      */
     private void setupDrawerToggling() {
         mDrawerLayout.addDrawerListener(mDrawerToggle);
         mDrawerLayout.addDrawerListener(
                 new DrawerLayout.DrawerListener() {
                     @Override
                     public void onDrawerSlide(View drawerView, float slideOffset) {}

                     @Override
                     public void onDrawerClosed(View drawerView) {
                         // If drawer is closed, revert stack/drawer to initial root state.
                         cleanupStackAndShowRoot();
                         scrollToPosition(0);
                     }

                     @Override
                     public void onDrawerOpened(View drawerView) {}

                     @Override
                     public void onDrawerStateChanged(int newState) {}
                 });
     }

     /**
      * Synchronizes the display of the drawer with its linked {@link DrawerLayout}.
      *
      * <p>This should be called from the associated Activity's
      * {@link androidx.appcompat.app.AppCompatActivity#onPostCreate(Bundle)} method to synchronize
      * after teh DRawerLayout's instance state has been restored, and any other time when the
      * state may have diverged in such a way that this controller's associated
      * {@link ActionBarDrawerToggle} had not been notified.
      */
     public void syncState() {
         mDrawerToggle.syncState();
     }

     /**
      * Notify this controller that device configurations may have changed.
      *
      * <p>This method should be called from the associated Activity's
      * {@code onConfigurationChanged()} method.
      */
     public void onConfigurationChanged(Configuration newConfig) {
         // Pass any configuration change to the drawer toggle.
         mDrawerToggle.onConfigurationChanged(newConfig);
     }

     /**
      * Sets the given adapter as the one displaying the current contents of the drawer.
      *
      * <p>The drawer's title will also be derived from the given adapter.
      */
     private void setDisplayAdapter(CarDrawerAdapter adapter) {
         setToolbarTitleFrom(adapter);
         // NOTE: We don't use swapAdapter() since different levels in the Drawer may switch between
         // car_drawer_list_item_normal, car_drawer_list_item_small and car_list_empty layouts.
         mDrawerList.getRecyclerView().setAdapter(adapter);
     }

     /**
      * An analog to an Activity's {@code onOptionsItemSelected()}. This method should be called
      * when the Activity's method is called and will return {@code true} if the selection has
      * been handled.
      *
      * @return {@code true} if the item processing was handled by this class.
      */
     public boolean onOptionsItemSelected(MenuItem item) {
         // Handle home-click and see if we can navigate up in the drawer.
         if (item != null && item.getItemId() == android.R.id.home && maybeHandleUpClick()) {
             return true;
         }

         // DrawerToggle gets next chance to handle up-clicks (and any other clicks).
         return mDrawerToggle.onOptionsItemSelected(item);
     }

     /**
      * Switches to the previous level in the drawer hierarchy if the current list being displayed
      * is not the root adapter. This is analogous to a navigate up.
      *
      * @return {@code true} if a navigate up was possible and executed. {@code false} otherwise.
      */
     private boolean maybeHandleUpClick() {
         // Check if already at the root level.
         if (mAdapterStack.size() <= 1) {
             return false;
         }

         CarDrawerAdapter adapter = mAdapterStack.pop();
         adapter.setTitleChangeListener(null);
         adapter.cleanup();
         setDisplayAdapter(mAdapterStack.peek());
         runLayoutAnimation(NAVIGATE_UP_ANIM);
         return true;
     }

     /** Clears stack down to root adapter and switches to root adapter. */
     private void cleanupStackAndShowRoot() {
         while (mAdapterStack.size() > 1) {
             CarDrawerAdapter adapter = mAdapterStack.pop();
             adapter.setTitleChangeListener(null);
             adapter.cleanup();
         }
         setDisplayAdapter(mAdapterStack.peek());
         runLayoutAnimation(NAVIGATE_UP_ANIM);
     }

     /**
      * Runs the given layout animation on the PagedListView. Running this animation will also
      * refresh the contents of the list.
      */
     private void runLayoutAnimation(@AnimRes int animation) {
         RecyclerView recyclerView = mDrawerList.getRecyclerView();
         recyclerView.setLayoutAnimation(AnimationUtils.loadLayoutAnimation(mContext, animation));
         recyclerView.getAdapter().notifyDataSetChanged();
         recyclerView.scheduleLayoutAnimation();
     }
 }
	/*
	* Copyright (C) 2017 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 androidx.car.drawer;

	import android.content.Context;
	import android.content.res.Configuration;
	import android.os.Bundle;
	import android.view.Gravity;
	import android.view.MenuItem;
	import android.view.View;
	import android.view.animation.AnimationUtils;
	import android.widget.ProgressBar;
	import android.widget.TextView;

	import androidx.annotation.AnimRes;
	import androidx.annotation.NonNull;
	import androidx.annotation.Nullable;
	import androidx.appcompat.app.ActionBarDrawerToggle;
	import androidx.appcompat.widget.Toolbar;
	import androidx.car.R;
	import androidx.car.widget.PagedListView;
	import androidx.drawerlayout.widget.DrawerLayout;
	import androidx.recyclerview.widget.RecyclerView;

	import java.util.ArrayDeque;

	/**
	* A controller that will handle the set up of the navigation drawer. It will hook up the
	* necessary buttons for up navigation, as well as expose methods to allow for a drill down
	* navigation.
	*/
	public class CarDrawerController {
	/** An animation for when a user navigates into a submenu. */
	@AnimRes
	private static final int DRILL_DOWN_ANIM = R.anim.fade_in_trans_right_layout_anim;

	/** An animation for when a user navigates up (when the back button is pressed). */
	@AnimRes
	private static final int NAVIGATE_UP_ANIM = R.anim.fade_in_trans_left_layout_anim;

	/**
	* A representation of the hierarchy of navigation being displayed in the list. The ordering of
	* this stack is the order that the user has visited each level. When the user navigates up,
	* the adapters are popped from this list.
	*/
	private final ArrayDeque<CarDrawerAdapter> mAdapterStack = new ArrayDeque<>();

	private final Context mContext;

	private final TextView mTitleView;
	private final DrawerLayout mDrawerLayout;
	private final ActionBarDrawerToggle mDrawerToggle;

	private final PagedListView mDrawerList;
	private final ProgressBar mProgressBar;

	/**
	* @deprecated Use {@link #CarDrawerController(DrawerLayout, ActionBarDrawerToggle)} instead.
	* The {@code Toolbar} is no longer needed and will be ignored.
	*/
	@Deprecated
	public CarDrawerController(@Nullable Toolbar toolbar, @NonNull DrawerLayout drawerLayout,
	@NonNull ActionBarDrawerToggle drawerToggle) {
	this(drawerLayout, drawerToggle);
	}

	/**
	* Creates a {@link CarDrawerController} that will control the navigation of the drawer given by
	* {@code drawerLayout}.
	*
	* <p>The given {@code drawerLayout} should either have a child View that is inflated from
	* {@code R.layout.car_drawer} or ensure that it three children that have the IDs found in that
	* layout.
	*
	* @param drawerLayout The top-level container for the window content that shows the
	* interactive drawer.
	* @param drawerToggle The {@link ActionBarDrawerToggle} that will open the drawer.
	*/
	public CarDrawerController(@NonNull DrawerLayout drawerLayout,
	@NonNull ActionBarDrawerToggle drawerToggle) {
	mContext = drawerLayout.getContext();
	mDrawerToggle = drawerToggle;
	mDrawerLayout = drawerLayout;

	mTitleView = drawerLayout.findViewById(R.id.drawer_title);
	mDrawerList = drawerLayout.findViewById(R.id.drawer_list);
	mDrawerList.setMaxPages(PagedListView.ItemCap.UNLIMITED);
	mProgressBar = drawerLayout.findViewById(R.id.drawer_progress);

	drawerLayout.findViewById(R.id.drawer_back_button).setOnClickListener(v -> {
	if (!maybeHandleUpClick()) {
	closeDrawer();
	}
	});

	setupDrawerToggling();
	}

	/**
	* Sets the {@link CarDrawerAdapter} that will function as the root adapter. The contents of
	* this root adapter are shown when the drawer is first opened. It is also the top-most level of
	* navigation in the drawer.
	*
	* @param rootAdapter The adapter that will act as the root. If this value is {@code null}, then
	* this method will do nothing.
	*/
	public void setRootAdapter(@Nullable CarDrawerAdapter rootAdapter) {
	if (rootAdapter == null) {
	return;
	}

	// The root adapter is always the last item in the stack.
	if (!mAdapterStack.isEmpty()) {
	mAdapterStack.removeLast();
	}
	mAdapterStack.addLast(rootAdapter);
	setDisplayAdapter(rootAdapter);
	}

	/**
	* Switches to use the given {@link CarDrawerAdapter} as the one to supply the list to display
	* in the navigation drawer. The title will also be updated from the adapter.
	*
	* <p>This switch is treated as a navigation to the next level in the drawer. Navigation away
	* from this level will pop the given adapter off and surface contents of the previous adapter
	* that was set via this method. If no such adapter exists, then the root adapter set by
	* {@link #setRootAdapter(CarDrawerAdapter)} will be used instead.
	*
	* @param adapter Adapter for next level of content in the drawer.
	*/
	public final void pushAdapter(CarDrawerAdapter adapter) {
	mAdapterStack.peek().setTitleChangeListener(null);
	mAdapterStack.push(adapter);
	setDisplayAdapter(adapter);
	runLayoutAnimation(DRILL_DOWN_ANIM);
	}

	/** Close the drawer. */
	public void closeDrawer() {
	if (mDrawerLayout.isDrawerOpen(Gravity.LEFT)) {
	mDrawerLayout.closeDrawer(Gravity.LEFT);
	}
	}

	/** Opens the drawer. */
	public void openDrawer() {
	if (!mDrawerLayout.isDrawerOpen(Gravity.LEFT)) {
	mDrawerLayout.openDrawer(Gravity.LEFT);
	}
	}

	/** Sets a listener to be notified of Drawer events. */
	public void addDrawerListener(@NonNull DrawerLayout.DrawerListener listener) {
	mDrawerLayout.addDrawerListener(listener);
	}

	/** Removes a listener to be notified of Drawer events. */
	public void removeDrawerListener(@NonNull DrawerLayout.DrawerListener listener) {
	mDrawerLayout.removeDrawerListener(listener);
	}

	/**
	* Sets whether the loading progress bar is displayed in the navigation drawer. If {@code true},
	* the progress bar is displayed and the navigation list is hidden and vice versa.
	*/
	public void showLoadingProgressBar(boolean show) {
	mDrawerList.setVisibility(show ? View.INVISIBLE : View.VISIBLE);
	mProgressBar.setVisibility(show ? View.VISIBLE : View.GONE);
	}

	/** Scroll to given position in the list. */
	public void scrollToPosition(int position) {
	mDrawerList.getRecyclerView().smoothScrollToPosition(position);
	}

	/**
	* Retrieves the title from the given {@link CarDrawerAdapter} and set its as the title of this
	* controller's internal Toolbar.
	*/
	private void setToolbarTitleFrom(CarDrawerAdapter adapter) {
	mTitleView.setText(adapter.getTitle());
	adapter.setTitleChangeListener(mTitleView::setText);
	}

	/**
	* Sets up the necessary listeners for {@link DrawerLayout} so that the navigation drawer
	* hierarchy is properly displayed.
	*/
	private void setupDrawerToggling() {
	mDrawerLayout.addDrawerListener(mDrawerToggle);
	mDrawerLayout.addDrawerListener(
	new DrawerLayout.DrawerListener() {
	@Override
	public void onDrawerSlide(View drawerView, float slideOffset) {}

	@Override
	public void onDrawerClosed(View drawerView) {
	// If drawer is closed, revert stack/drawer to initial root state.
	cleanupStackAndShowRoot();
	scrollToPosition(0);
	}

	@Override
	public void onDrawerOpened(View drawerView) {}

	@Override
	public void onDrawerStateChanged(int newState) {}
	});
	}

	/**
	* Synchronizes the display of the drawer with its linked {@link DrawerLayout}.
	*
	* <p>This should be called from the associated Activity's
	* {@link androidx.appcompat.app.AppCompatActivity#onPostCreate(Bundle)} method to synchronize
	* after teh DRawerLayout's instance state has been restored, and any other time when the
	* state may have diverged in such a way that this controller's associated
	* {@link ActionBarDrawerToggle} had not been notified.
	*/
	public void syncState() {
	mDrawerToggle.syncState();
	}

	/**
	* Notify this controller that device configurations may have changed.
	*
	* <p>This method should be called from the associated Activity's
	* {@code onConfigurationChanged()} method.
	*/
	public void onConfigurationChanged(Configuration newConfig) {
	// Pass any configuration change to the drawer toggle.
	mDrawerToggle.onConfigurationChanged(newConfig);
	}

	/**
	* Sets the given adapter as the one displaying the current contents of the drawer.
	*
	* <p>The drawer's title will also be derived from the given adapter.
	*/
	private void setDisplayAdapter(CarDrawerAdapter adapter) {
	setToolbarTitleFrom(adapter);
	// NOTE: We don't use swapAdapter() since different levels in the Drawer may switch between
	// car_drawer_list_item_normal, car_drawer_list_item_small and car_list_empty layouts.
	mDrawerList.getRecyclerView().setAdapter(adapter);
	}

	/**
	* An analog to an Activity's {@code onOptionsItemSelected()}. This method should be called
	* when the Activity's method is called and will return {@code true} if the selection has
	* been handled.
	*
	* @return {@code true} if the item processing was handled by this class.
	*/
	public boolean onOptionsItemSelected(MenuItem item) {
	// Handle home-click and see if we can navigate up in the drawer.
	if (item != null && item.getItemId() == android.R.id.home && maybeHandleUpClick()) {
	return true;
	}

	// DrawerToggle gets next chance to handle up-clicks (and any other clicks).
	return mDrawerToggle.onOptionsItemSelected(item);
	}

	/**
	* Switches to the previous level in the drawer hierarchy if the current list being displayed
	* is not the root adapter. This is analogous to a navigate up.
	*
	* @return {@code true} if a navigate up was possible and executed. {@code false} otherwise.
	*/
	private boolean maybeHandleUpClick() {
	// Check if already at the root level.
	if (mAdapterStack.size() <= 1) {
	return false;
	}

	CarDrawerAdapter adapter = mAdapterStack.pop();
	adapter.setTitleChangeListener(null);
	adapter.cleanup();
	setDisplayAdapter(mAdapterStack.peek());
	runLayoutAnimation(NAVIGATE_UP_ANIM);
	return true;
	}

	/** Clears stack down to root adapter and switches to root adapter. */
	private void cleanupStackAndShowRoot() {
	while (mAdapterStack.size() > 1) {
	CarDrawerAdapter adapter = mAdapterStack.pop();
	adapter.setTitleChangeListener(null);
	adapter.cleanup();
	}
	setDisplayAdapter(mAdapterStack.peek());
	runLayoutAnimation(NAVIGATE_UP_ANIM);
	}

	/**
	* Runs the given layout animation on the PagedListView. Running this animation will also
	* refresh the contents of the list.
	*/
	private void runLayoutAnimation(@AnimRes int animation) {
	RecyclerView recyclerView = mDrawerList.getRecyclerView();
	recyclerView.setLayoutAnimation(AnimationUtils.loadLayoutAnimation(mContext, animation));
	recyclerView.getAdapter().notifyDataSetChanged();
	recyclerView.scheduleLayoutAnimation();
	}
	}