src/com/android/wallpaper/widget/BottomActionBar.java - LeafOS-Project/android_packages_apps_WallpaperPicker2 - Gitiles

 /*
  * Copyright (C) 2020 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.android.wallpaper.widget;

 import static com.google.android.material.bottomsheet.BottomSheetBehavior.STATE_COLLAPSED;
 import static com.google.android.material.bottomsheet.BottomSheetBehavior.STATE_EXPANDED;

 import android.app.Activity;
 import android.content.Context;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;

 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;

 import com.android.wallpaper.R;
 import com.android.wallpaper.util.SizeCalculator;

 import com.google.android.material.bottomsheet.BottomSheetBehavior;
 import com.google.android.material.bottomsheet.BottomSheetBehavior.BottomSheetCallback;

 import java.util.ArrayDeque;
 import java.util.Arrays;
 import java.util.Deque;
 import java.util.EnumMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;

 /** A {@code ViewGroup} which provides the specific actions for the user to interact with. */
 public class BottomActionBar extends FrameLayout {

     /**
      * Interface to be implemented by an Activity hosting a {@link BottomActionBar}
      */
     public interface BottomActionBarHost {
         /** Gets {@link BottomActionBar}. */
         BottomActionBar getBottomActionBar();
     }

     /**
      * The listener for {@link BottomActionBar} visibility change notification.
      */
     public interface VisibilityChangeListener {
         /**
          * Called when {@link BottomActionBar} visibility changes.
          *
          * @param isVisible {@code true} if it's visible; {@code false} otherwise.
          */
         void onVisibilityChange(boolean isVisible);
     }

     /** This listens to changes to an action view's selected state. */
     public interface OnActionSelectedListener {

         /**
          * This is called when an action view's selected state changes.
          * @param selected whether the action view is selected.
          */
         void onActionSelected(boolean selected);
     }

     /**
      *  A Callback to notify the registrant to change it's accessibility param when
      *  {@link BottomActionBar} state changes.
      */
     public interface AccessibilityCallback {
         /**
          * Called when {@link BottomActionBar} collapsed.
          */
         void onBottomSheetCollapsed();

         /**
          * Called when {@link BottomActionBar} expanded.
          */
         void onBottomSheetExpanded();
     }

     // TODO(b/154299462): Separate downloadable related actions from WallpaperPicker.
     /** The action items in the bottom action bar. */
     public enum BottomAction {
         ROTATION, DELETE, INFORMATION, EDIT, CUSTOMIZE, DOWNLOAD, PROGRESS, APPLY
     }

     private final Map<BottomAction, View> mActionMap = new EnumMap<>(BottomAction.class);
     private final Map<BottomAction, View> mContentViewMap = new EnumMap<>(BottomAction.class);
     private final Map<BottomAction, OnActionSelectedListener> mActionSelectedListeners =
             new EnumMap<>(BottomAction.class);

     private final ViewGroup mBottomSheetView;
     private final QueueStateBottomSheetBehavior<ViewGroup> mBottomSheetBehavior;
     private final Set<VisibilityChangeListener> mVisibilityChangeListeners = new HashSet<>();

     // The current selected action in the BottomActionBar, can be null when no action is selected.
     @Nullable private BottomAction mSelectedAction;
     @Nullable private AccessibilityCallback mAccessibilityCallback;

     public BottomActionBar(@NonNull Context context, @Nullable AttributeSet attrs) {
         super(context, attrs);
         LayoutInflater.from(context).inflate(R.layout.bottom_actions_layout, this, true);

         mActionMap.put(BottomAction.ROTATION, findViewById(R.id.action_rotation));
         mActionMap.put(BottomAction.DELETE, findViewById(R.id.action_delete));
         mActionMap.put(BottomAction.INFORMATION, findViewById(R.id.action_information));
         mActionMap.put(BottomAction.EDIT, findViewById(R.id.action_edit));
         mActionMap.put(BottomAction.CUSTOMIZE, findViewById(R.id.action_customize));
         mActionMap.put(BottomAction.DOWNLOAD, findViewById(R.id.action_download));
         mActionMap.put(BottomAction.PROGRESS, findViewById(R.id.action_progress));
         mActionMap.put(BottomAction.APPLY, findViewById(R.id.action_apply));

         mBottomSheetView = findViewById(R.id.action_bottom_sheet);
         SizeCalculator.adjustBackgroundCornerRadius(mBottomSheetView);

         mBottomSheetBehavior = (QueueStateBottomSheetBehavior<ViewGroup>) BottomSheetBehavior.from(
                 mBottomSheetView);
         mBottomSheetBehavior.setState(STATE_COLLAPSED);
         mBottomSheetBehavior.setBottomSheetCallback(new BottomSheetCallback() {
             @Override
             public void onStateChanged(@NonNull View bottomSheet, int newState) {
                 if (mBottomSheetBehavior.isQueueProcessing()) {
                     // Avoid button and bottom sheet mismatching from quick tapping buttons when
                     // bottom sheet is changing state.
                     disableActions();
                     // If bottom sheet is going with expanded-collapsed-expanded, the new content
                     // will be updated in collapsed state. The first state change from expanded to
                     // collapsed should still show the previous content view.
                     if (mSelectedAction != null && newState == STATE_COLLAPSED) {
                         updateContentViewFor(mSelectedAction);
                     }
                     return;
                 }

                 notifyAccessibilityCallback(newState);

                 // Enable all buttons when queue is not processing.
                 enableActions();
                 if (!isExpandable(mSelectedAction)) {
                     return;
                 }
                 // Ensure the button state is the same as bottom sheet state to catch up the state
                 // change from dragging or some unexpected bottom sheet state changes.
                 if (newState == STATE_COLLAPSED) {
                     updateSelectedState(mSelectedAction, /* selected= */ false);
                 } else if (newState == STATE_EXPANDED) {
                     updateSelectedState(mSelectedAction, /* selected= */ true);
                 }
             }
             @Override
             public void onSlide(@NonNull View bottomSheet, float slideOffset) { }
         });

         setOnApplyWindowInsetsListener((v, windowInsets) -> {
             v.setPadding(v.getPaddingLeft(), v.getPaddingTop(), v.getPaddingRight(),
                     windowInsets.getSystemWindowInsetBottom());
             return windowInsets;
         });
     }

     @Override
     public void onVisibilityAggregated(boolean isVisible) {
         super.onVisibilityAggregated(isVisible);
         if (!isVisible) {
             hideBottomSheetAndDeselectButtonIfExpanded();
             mBottomSheetBehavior.reset();
         }
         mVisibilityChangeListeners.forEach(listener -> listener.onVisibilityChange(isVisible));
     }

     /**
      * Adds content view to the bottom sheet and binds with a {@code BottomAction} to
      * expand / collapse the bottom sheet.
      *
      * @param contentView the view with content to be added on the bottom sheet
      * @param action the action to be bound to expand / collapse the bottom sheet
      */
     public void attachViewToBottomSheetAndBindAction(View contentView, BottomAction action) {
         contentView.setVisibility(GONE);
         contentView.setFocusable(true);
         mContentViewMap.put(action, contentView);
         mBottomSheetView.addView(contentView);
         setActionClickListener(action, actionView -> {
             if (mBottomSheetBehavior.getState() == STATE_COLLAPSED) {
                 updateContentViewFor(action);
             }
             mBottomSheetView.setAccessibilityTraversalAfter(actionView.getId());
         });
     }

     /** Collapses the bottom sheet. */
     public void collapseBottomSheetIfExpanded() {
         hideBottomSheetAndDeselectButtonIfExpanded();
     }

     /**
      * Sets a click listener to a specific action.
      *
      * @param bottomAction the specific action
      * @param actionClickListener the click listener for the action
      */
     public void setActionClickListener(
             BottomAction bottomAction, OnClickListener actionClickListener) {
         View buttonView = mActionMap.get(bottomAction);
         if (buttonView.hasOnClickListeners()) {
             throw new IllegalStateException(
                     "Had already set a click listener to button: " + bottomAction);
         }
         buttonView.setOnClickListener(view -> {
             if (mSelectedAction != null && isActionSelected(mSelectedAction)) {
                 updateSelectedState(mSelectedAction, /* selected= */ false);
                 if (isExpandable(mSelectedAction)) {
                     mBottomSheetBehavior.enqueue(STATE_COLLAPSED);
                 }
             } else {
                 // Error handling, set to null if the action is not selected.
                 mSelectedAction = null;
             }

             if (bottomAction == mSelectedAction) {
                 // Deselect the selected action.
                 mSelectedAction = null;
             } else {
                 // Select a different action from the current selected action.
                 mSelectedAction = bottomAction;
                 updateSelectedState(mSelectedAction, /* selected= */ true);
                 if (isExpandable(mSelectedAction)) {
                     mBottomSheetBehavior.enqueue(STATE_EXPANDED);
                 }
             }
             actionClickListener.onClick(view);
             mBottomSheetBehavior.processQueueForStateChange();
         });
     }

     /**
      * Sets a selected listener to a specific action. This is triggered each time the bottom
      * action's selected state changes.
      *
      * @param bottomAction the specific action
      * @param actionSelectedListener the selected listener for the action
      */
     public void setActionSelectedListener(
             BottomAction bottomAction, OnActionSelectedListener actionSelectedListener) {
         if (mActionSelectedListeners.containsKey(bottomAction)) {
             throw new IllegalStateException(
                     "Had already set a selected listener to button: " + bottomAction);
         }
         mActionSelectedListeners.put(bottomAction, actionSelectedListener);
     }

     /** Binds the cancel button to back key. */
     public void bindBackButtonToSystemBackKey(Activity activity) {
         findViewById(R.id.action_back).setOnClickListener(v -> activity.onBackPressed());
     }

     /** Returns {@code true} if visible. */
     public boolean isVisible() {
         return getVisibility() == VISIBLE;
     }

     /** Shows {@link BottomActionBar}. */
     public void show() {
         setVisibility(VISIBLE);
     }

     /** Hides {@link BottomActionBar}. */
     public void hide() {
         setVisibility(GONE);
     }

     /**
      * Adds the visibility change listener.
      *
      * @param visibilityChangeListener the listener to be notified.
      */
     public void addVisibilityChangeListener(VisibilityChangeListener visibilityChangeListener) {
         if (visibilityChangeListener == null) {
             return;
         }
         mVisibilityChangeListeners.add(visibilityChangeListener);
         visibilityChangeListener.onVisibilityChange(isVisible());
     }

     /**
      * Sets a AccessibilityCallback.
      *
      * @param accessibilityCallback the callback to be notified.
      */
     public void setAccessibilityCallback(@Nullable AccessibilityCallback accessibilityCallback) {
         mAccessibilityCallback = accessibilityCallback;
     }

     /**
      * Shows the specific actions.
      *
      * @param actions the specific actions
      */
     public void showActions(BottomAction... actions) {
         for (BottomAction action : actions) {
             mActionMap.get(action).setVisibility(VISIBLE);
         }
     }

     /**
      * Hides the specific actions.
      *
      * @param actions the specific actions
      */
     public void hideActions(BottomAction... actions) {
         for (BottomAction action : actions) {
             mActionMap.get(action).setVisibility(GONE);

             if (isExpandable(action) && mSelectedAction == action) {
                 hideBottomSheetAndDeselectButtonIfExpanded();
             }
         }
     }

     /**
      * Shows the specific actions only. In other words, the other actions will be hidden.
      *
      * @param actions the specific actions which will be shown. Others will be hidden.
      */
     public void showActionsOnly(BottomAction... actions) {
         final Set<BottomAction> actionsSet = new HashSet<>(Arrays.asList(actions));

         mActionMap.keySet().forEach(action -> {
             if (actionsSet.contains(action)) {
                 showActions(action);
             } else {
                 hideActions(action);
             }
         });
     }

     /**
      * Checks if the specific actions are shown.
      *
      * @param actions the specific actions to be verified
      * @return {@code true} if the actions are shown; {@code false} otherwise
      */
     public boolean areActionsShown(BottomAction... actions) {
         final Set<BottomAction> actionsSet = new HashSet<>(Arrays.asList(actions));
         return actionsSet.stream().allMatch(bottomAction -> {
             View view = mActionMap.get(bottomAction);
             return view != null && view.getVisibility() == VISIBLE;
         });
     }

     /**
      * All actions will be hidden.
      */
     public void hideAllActions() {
         showActionsOnly(/* No actions to show */);
     }

     /** Enables all the actions' {@link View}. */
     public void enableActions() {
         enableActions(BottomAction.values());
     }

     /** Disables all the actions' {@link View}. */
     public void disableActions() {
         disableActions(BottomAction.values());
     }

     /**
      * Enables specified actions' {@link View}.
      *
      * @param actions the specified actions to enable their views
      */
     public void enableActions(BottomAction... actions) {
         for (BottomAction action : actions) {
             mActionMap.get(action).setEnabled(true);
         }
     }

     /**
      * Disables specified actions' {@link View}.
      *
      * @param actions the specified actions to disable their views
      */
     public void disableActions(BottomAction... actions) {
         for (BottomAction action : actions) {
             mActionMap.get(action).setEnabled(false);
         }
     }

     /** Sets a default selected action button. */
     public void setDefaultSelectedButton(BottomAction action) {
         if (mSelectedAction == null) {
             mSelectedAction = action;
             updateSelectedState(mSelectedAction, /* selected= */ true);
         }
     }

     /** Deselects an action button. */
     public void deselectAction(BottomAction action) {
         if (isExpandable(action)) {
             mBottomSheetBehavior.setState(STATE_COLLAPSED);
         }
         updateSelectedState(action, /* selected= */ false);
         if (action == mSelectedAction) {
             mSelectedAction = null;
         }
     }

     public boolean isActionSelected(BottomAction action) {
         return mActionMap.get(action).isSelected();
     }

     /** Resets {@link BottomActionBar} to initial state. */
     public void reset() {
         // Not visible by default, see res/layout/bottom_action_bar.xml
         hide();
         // All actions are hide and enabled by default, see res/layout/bottom_action_bar.xml
         hideAllActions();
         enableActions();
         // Clears all the actions' click listeners
         mActionMap.values().forEach(v -> v.setOnClickListener(null));
         findViewById(R.id.action_back).setOnClickListener(null);
         // Deselect all buttons.
         mActionMap.keySet().forEach(a -> updateSelectedState(a, /* selected= */ false));
         // Clear values.
         mContentViewMap.clear();
         mActionSelectedListeners.clear();
         mBottomSheetView.removeAllViews();
         mBottomSheetBehavior.reset();
         mSelectedAction = null;
     }

     private void updateSelectedState(BottomAction bottomAction, boolean selected) {
         View bottomActionView = mActionMap.get(bottomAction);
         if (bottomActionView.isSelected() == selected) {
             return;
         }

         OnActionSelectedListener listener = mActionSelectedListeners.get(bottomAction);
         if (listener != null) {
             listener.onActionSelected(selected);
         }
         bottomActionView.setSelected(selected);
     }

     private void hideBottomSheetAndDeselectButtonIfExpanded() {
         if (isExpandable(mSelectedAction) && mBottomSheetBehavior.getState() == STATE_EXPANDED) {
             mBottomSheetBehavior.setState(STATE_COLLAPSED);
             updateSelectedState(mSelectedAction, /* selected= */ false);
             mSelectedAction = null;
         }
     }

     private void updateContentViewFor(BottomAction action) {
         mContentViewMap.forEach((a, v) -> v.setVisibility(a.equals(action) ? VISIBLE : GONE));
     }

     private boolean isExpandable(BottomAction action) {
         return action != null && mContentViewMap.containsKey(action);
     }

     private void notifyAccessibilityCallback(int state) {
         if (mAccessibilityCallback != null) {
             return;
         }

         if (state == STATE_COLLAPSED) {
             mAccessibilityCallback.onBottomSheetCollapsed();
         } else if (state == STATE_EXPANDED) {
             mAccessibilityCallback.onBottomSheetExpanded();
         }
     }

     /** A {@link BottomSheetBehavior} that can process a queue of bottom sheet states.*/
     public static class QueueStateBottomSheetBehavior<V extends View>
             extends BottomSheetBehavior<V> {

         private final Deque<Integer> mStateQueue = new ArrayDeque<>();
         private boolean mIsQueueProcessing;

         public QueueStateBottomSheetBehavior(Context context, @Nullable AttributeSet attrs) {
             super(context, attrs);
             // Binds the default callback for processing queue.
             setBottomSheetCallback(null);
         }

         /** Enqueues the bottom sheet states. */
         public void enqueue(int state) {
             if (!mStateQueue.isEmpty() && mStateQueue.getLast() == state) {
                 return;
             }
             mStateQueue.add(state);
         }

         /** Processes the queue of bottom sheet state that was set via {@link #enqueue}. */
         public void processQueueForStateChange() {
             if (mStateQueue.isEmpty()) {
                 return;
             }
             setState(mStateQueue.getFirst());
             mIsQueueProcessing = true;
         }

         /**
          * Returns {@code true} if the queue is processing. For example, if the bottom sheet is
          * going with expanded-collapsed-expanded, it would return {@code true} until last expanded
          * state is finished.
          */
         public boolean isQueueProcessing() {
             return mIsQueueProcessing;
         }

         /** Resets the queue state. */
         public void reset() {
             mStateQueue.clear();
             mIsQueueProcessing = false;
         }

         @Override
         public void setBottomSheetCallback(BottomSheetCallback callback) {
             super.setBottomSheetCallback(new BottomSheetCallback() {
                 @Override
                 public void onStateChanged(@NonNull View bottomSheet, int newState) {
                     if (!mStateQueue.isEmpty()) {
                         if (newState == mStateQueue.getFirst()) {
                             mStateQueue.removeFirst();
                             if (mStateQueue.isEmpty()) {
                                 mIsQueueProcessing = false;
                             } else {
                                 setState(mStateQueue.getFirst());
                             }
                         } else {
                             setState(mStateQueue.getFirst());
                         }
                     }

                     if (callback != null) {
                         callback.onStateChanged(bottomSheet, newState);
                     }
                 }

                 @Override
                 public void onSlide(@NonNull View bottomSheet, float slideOffset) {
                     if (callback != null) {
                         callback.onSlide(bottomSheet, slideOffset);
                     }
                 }
             });
         }
     }
 }
	/*
	* Copyright (C) 2020 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.android.wallpaper.widget;

	import static com.google.android.material.bottomsheet.BottomSheetBehavior.STATE_COLLAPSED;
	import static com.google.android.material.bottomsheet.BottomSheetBehavior.STATE_EXPANDED;

	import android.app.Activity;
	import android.content.Context;
	import android.util.AttributeSet;
	import android.view.LayoutInflater;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.FrameLayout;

	import androidx.annotation.NonNull;
	import androidx.annotation.Nullable;

	import com.android.wallpaper.R;
	import com.android.wallpaper.util.SizeCalculator;

	import com.google.android.material.bottomsheet.BottomSheetBehavior;
	import com.google.android.material.bottomsheet.BottomSheetBehavior.BottomSheetCallback;

	import java.util.ArrayDeque;
	import java.util.Arrays;
	import java.util.Deque;
	import java.util.EnumMap;
	import java.util.HashSet;
	import java.util.Map;
	import java.util.Set;

	/** A {@code ViewGroup} which provides the specific actions for the user to interact with. */
	public class BottomActionBar extends FrameLayout {

	/**
	* Interface to be implemented by an Activity hosting a {@link BottomActionBar}
	*/
	public interface BottomActionBarHost {
	/** Gets {@link BottomActionBar}. */
	BottomActionBar getBottomActionBar();
	}

	/**
	* The listener for {@link BottomActionBar} visibility change notification.
	*/
	public interface VisibilityChangeListener {
	/**
	* Called when {@link BottomActionBar} visibility changes.
	*
	* @param isVisible {@code true} if it's visible; {@code false} otherwise.
	*/
	void onVisibilityChange(boolean isVisible);
	}

	/** This listens to changes to an action view's selected state. */
	public interface OnActionSelectedListener {

	/**
	* This is called when an action view's selected state changes.
	* @param selected whether the action view is selected.
	*/
	void onActionSelected(boolean selected);
	}

	/**
	* A Callback to notify the registrant to change it's accessibility param when
	* {@link BottomActionBar} state changes.
	*/
	public interface AccessibilityCallback {
	/**
	* Called when {@link BottomActionBar} collapsed.
	*/
	void onBottomSheetCollapsed();

	/**
	* Called when {@link BottomActionBar} expanded.
	*/
	void onBottomSheetExpanded();
	}

	// TODO(b/154299462): Separate downloadable related actions from WallpaperPicker.
	/** The action items in the bottom action bar. */
	public enum BottomAction {
	ROTATION, DELETE, INFORMATION, EDIT, CUSTOMIZE, DOWNLOAD, PROGRESS, APPLY
	}

	private final Map<BottomAction, View> mActionMap = new EnumMap<>(BottomAction.class);
	private final Map<BottomAction, View> mContentViewMap = new EnumMap<>(BottomAction.class);
	private final Map<BottomAction, OnActionSelectedListener> mActionSelectedListeners =
	new EnumMap<>(BottomAction.class);

	private final ViewGroup mBottomSheetView;
	private final QueueStateBottomSheetBehavior<ViewGroup> mBottomSheetBehavior;
	private final Set<VisibilityChangeListener> mVisibilityChangeListeners = new HashSet<>();

	// The current selected action in the BottomActionBar, can be null when no action is selected.
	@Nullable private BottomAction mSelectedAction;
	@Nullable private AccessibilityCallback mAccessibilityCallback;

	public BottomActionBar(@NonNull Context context, @Nullable AttributeSet attrs) {
	super(context, attrs);
	LayoutInflater.from(context).inflate(R.layout.bottom_actions_layout, this, true);

	mActionMap.put(BottomAction.ROTATION, findViewById(R.id.action_rotation));
	mActionMap.put(BottomAction.DELETE, findViewById(R.id.action_delete));
	mActionMap.put(BottomAction.INFORMATION, findViewById(R.id.action_information));
	mActionMap.put(BottomAction.EDIT, findViewById(R.id.action_edit));
	mActionMap.put(BottomAction.CUSTOMIZE, findViewById(R.id.action_customize));
	mActionMap.put(BottomAction.DOWNLOAD, findViewById(R.id.action_download));
	mActionMap.put(BottomAction.PROGRESS, findViewById(R.id.action_progress));
	mActionMap.put(BottomAction.APPLY, findViewById(R.id.action_apply));

	mBottomSheetView = findViewById(R.id.action_bottom_sheet);
	SizeCalculator.adjustBackgroundCornerRadius(mBottomSheetView);

	mBottomSheetBehavior = (QueueStateBottomSheetBehavior<ViewGroup>) BottomSheetBehavior.from(
	mBottomSheetView);
	mBottomSheetBehavior.setState(STATE_COLLAPSED);
	mBottomSheetBehavior.setBottomSheetCallback(new BottomSheetCallback() {
	@Override
	public void onStateChanged(@NonNull View bottomSheet, int newState) {
	if (mBottomSheetBehavior.isQueueProcessing()) {
	// Avoid button and bottom sheet mismatching from quick tapping buttons when
	// bottom sheet is changing state.
	disableActions();
	// If bottom sheet is going with expanded-collapsed-expanded, the new content
	// will be updated in collapsed state. The first state change from expanded to
	// collapsed should still show the previous content view.
	if (mSelectedAction != null && newState == STATE_COLLAPSED) {
	updateContentViewFor(mSelectedAction);
	}
	return;
	}

	notifyAccessibilityCallback(newState);

	// Enable all buttons when queue is not processing.
	enableActions();
	if (!isExpandable(mSelectedAction)) {
	return;
	}
	// Ensure the button state is the same as bottom sheet state to catch up the state
	// change from dragging or some unexpected bottom sheet state changes.
	if (newState == STATE_COLLAPSED) {
	updateSelectedState(mSelectedAction, /* selected= */ false);
	} else if (newState == STATE_EXPANDED) {
	updateSelectedState(mSelectedAction, /* selected= */ true);
	}
	}
	@Override
	public void onSlide(@NonNull View bottomSheet, float slideOffset) { }
	});

	setOnApplyWindowInsetsListener((v, windowInsets) -> {
	v.setPadding(v.getPaddingLeft(), v.getPaddingTop(), v.getPaddingRight(),
	windowInsets.getSystemWindowInsetBottom());
	return windowInsets;
	});
	}

	@Override
	public void onVisibilityAggregated(boolean isVisible) {
	super.onVisibilityAggregated(isVisible);
	if (!isVisible) {
	hideBottomSheetAndDeselectButtonIfExpanded();
	mBottomSheetBehavior.reset();
	}
	mVisibilityChangeListeners.forEach(listener -> listener.onVisibilityChange(isVisible));
	}

	/**
	* Adds content view to the bottom sheet and binds with a {@code BottomAction} to
	* expand / collapse the bottom sheet.
	*
	* @param contentView the view with content to be added on the bottom sheet
	* @param action the action to be bound to expand / collapse the bottom sheet
	*/
	public void attachViewToBottomSheetAndBindAction(View contentView, BottomAction action) {
	contentView.setVisibility(GONE);
	contentView.setFocusable(true);
	mContentViewMap.put(action, contentView);
	mBottomSheetView.addView(contentView);
	setActionClickListener(action, actionView -> {
	if (mBottomSheetBehavior.getState() == STATE_COLLAPSED) {
	updateContentViewFor(action);
	}
	mBottomSheetView.setAccessibilityTraversalAfter(actionView.getId());
	});
	}

	/** Collapses the bottom sheet. */
	public void collapseBottomSheetIfExpanded() {
	hideBottomSheetAndDeselectButtonIfExpanded();
	}

	/**
	* Sets a click listener to a specific action.
	*
	* @param bottomAction the specific action
	* @param actionClickListener the click listener for the action
	*/
	public void setActionClickListener(
	BottomAction bottomAction, OnClickListener actionClickListener) {
	View buttonView = mActionMap.get(bottomAction);
	if (buttonView.hasOnClickListeners()) {
	throw new IllegalStateException(
	"Had already set a click listener to button: " + bottomAction);
	}
	buttonView.setOnClickListener(view -> {
	if (mSelectedAction != null && isActionSelected(mSelectedAction)) {
	updateSelectedState(mSelectedAction, /* selected= */ false);
	if (isExpandable(mSelectedAction)) {
	mBottomSheetBehavior.enqueue(STATE_COLLAPSED);
	}
	} else {
	// Error handling, set to null if the action is not selected.
	mSelectedAction = null;
	}

	if (bottomAction == mSelectedAction) {
	// Deselect the selected action.
	mSelectedAction = null;
	} else {
	// Select a different action from the current selected action.
	mSelectedAction = bottomAction;
	updateSelectedState(mSelectedAction, /* selected= */ true);
	if (isExpandable(mSelectedAction)) {
	mBottomSheetBehavior.enqueue(STATE_EXPANDED);
	}
	}
	actionClickListener.onClick(view);
	mBottomSheetBehavior.processQueueForStateChange();
	});
	}

	/**
	* Sets a selected listener to a specific action. This is triggered each time the bottom
	* action's selected state changes.
	*
	* @param bottomAction the specific action
	* @param actionSelectedListener the selected listener for the action
	*/
	public void setActionSelectedListener(
	BottomAction bottomAction, OnActionSelectedListener actionSelectedListener) {
	if (mActionSelectedListeners.containsKey(bottomAction)) {
	throw new IllegalStateException(
	"Had already set a selected listener to button: " + bottomAction);
	}
	mActionSelectedListeners.put(bottomAction, actionSelectedListener);
	}

	/** Binds the cancel button to back key. */
	public void bindBackButtonToSystemBackKey(Activity activity) {
	findViewById(R.id.action_back).setOnClickListener(v -> activity.onBackPressed());
	}

	/** Returns {@code true} if visible. */
	public boolean isVisible() {
	return getVisibility() == VISIBLE;
	}

	/** Shows {@link BottomActionBar}. */
	public void show() {
	setVisibility(VISIBLE);
	}

	/** Hides {@link BottomActionBar}. */
	public void hide() {
	setVisibility(GONE);
	}

	/**
	* Adds the visibility change listener.
	*
	* @param visibilityChangeListener the listener to be notified.
	*/
	public void addVisibilityChangeListener(VisibilityChangeListener visibilityChangeListener) {
	if (visibilityChangeListener == null) {
	return;
	}
	mVisibilityChangeListeners.add(visibilityChangeListener);
	visibilityChangeListener.onVisibilityChange(isVisible());
	}

	/**
	* Sets a AccessibilityCallback.
	*
	* @param accessibilityCallback the callback to be notified.
	*/
	public void setAccessibilityCallback(@Nullable AccessibilityCallback accessibilityCallback) {
	mAccessibilityCallback = accessibilityCallback;
	}

	/**
	* Shows the specific actions.
	*
	* @param actions the specific actions
	*/
	public void showActions(BottomAction... actions) {
	for (BottomAction action : actions) {
	mActionMap.get(action).setVisibility(VISIBLE);
	}
	}

	/**
	* Hides the specific actions.
	*
	* @param actions the specific actions
	*/
	public void hideActions(BottomAction... actions) {
	for (BottomAction action : actions) {
	mActionMap.get(action).setVisibility(GONE);

	if (isExpandable(action) && mSelectedAction == action) {
	hideBottomSheetAndDeselectButtonIfExpanded();
	}
	}
	}

	/**
	* Shows the specific actions only. In other words, the other actions will be hidden.
	*
	* @param actions the specific actions which will be shown. Others will be hidden.
	*/
	public void showActionsOnly(BottomAction... actions) {
	final Set<BottomAction> actionsSet = new HashSet<>(Arrays.asList(actions));

	mActionMap.keySet().forEach(action -> {
	if (actionsSet.contains(action)) {
	showActions(action);
	} else {
	hideActions(action);
	}
	});
	}

	/**
	* Checks if the specific actions are shown.
	*
	* @param actions the specific actions to be verified
	* @return {@code true} if the actions are shown; {@code false} otherwise
	*/
	public boolean areActionsShown(BottomAction... actions) {
	final Set<BottomAction> actionsSet = new HashSet<>(Arrays.asList(actions));
	return actionsSet.stream().allMatch(bottomAction -> {
	View view = mActionMap.get(bottomAction);
	return view != null && view.getVisibility() == VISIBLE;
	});
	}

	/**
	* All actions will be hidden.
	*/
	public void hideAllActions() {
	showActionsOnly(/* No actions to show */);
	}

	/** Enables all the actions' {@link View}. */
	public void enableActions() {
	enableActions(BottomAction.values());
	}

	/** Disables all the actions' {@link View}. */
	public void disableActions() {
	disableActions(BottomAction.values());
	}

	/**
	* Enables specified actions' {@link View}.
	*
	* @param actions the specified actions to enable their views
	*/
	public void enableActions(BottomAction... actions) {
	for (BottomAction action : actions) {
	mActionMap.get(action).setEnabled(true);
	}
	}

	/**
	* Disables specified actions' {@link View}.
	*
	* @param actions the specified actions to disable their views
	*/
	public void disableActions(BottomAction... actions) {
	for (BottomAction action : actions) {
	mActionMap.get(action).setEnabled(false);
	}
	}

	/** Sets a default selected action button. */
	public void setDefaultSelectedButton(BottomAction action) {
	if (mSelectedAction == null) {
	mSelectedAction = action;
	updateSelectedState(mSelectedAction, /* selected= */ true);
	}
	}

	/** Deselects an action button. */
	public void deselectAction(BottomAction action) {
	if (isExpandable(action)) {
	mBottomSheetBehavior.setState(STATE_COLLAPSED);
	}
	updateSelectedState(action, /* selected= */ false);
	if (action == mSelectedAction) {
	mSelectedAction = null;
	}
	}

	public boolean isActionSelected(BottomAction action) {
	return mActionMap.get(action).isSelected();
	}

	/** Resets {@link BottomActionBar} to initial state. */
	public void reset() {
	// Not visible by default, see res/layout/bottom_action_bar.xml
	hide();
	// All actions are hide and enabled by default, see res/layout/bottom_action_bar.xml
	hideAllActions();
	enableActions();
	// Clears all the actions' click listeners
	mActionMap.values().forEach(v -> v.setOnClickListener(null));
	findViewById(R.id.action_back).setOnClickListener(null);
	// Deselect all buttons.
	mActionMap.keySet().forEach(a -> updateSelectedState(a, /* selected= */ false));
	// Clear values.
	mContentViewMap.clear();
	mActionSelectedListeners.clear();
	mBottomSheetView.removeAllViews();
	mBottomSheetBehavior.reset();
	mSelectedAction = null;
	}

	private void updateSelectedState(BottomAction bottomAction, boolean selected) {
	View bottomActionView = mActionMap.get(bottomAction);
	if (bottomActionView.isSelected() == selected) {
	return;
	}

	OnActionSelectedListener listener = mActionSelectedListeners.get(bottomAction);
	if (listener != null) {
	listener.onActionSelected(selected);
	}
	bottomActionView.setSelected(selected);
	}

	private void hideBottomSheetAndDeselectButtonIfExpanded() {
	if (isExpandable(mSelectedAction) && mBottomSheetBehavior.getState() == STATE_EXPANDED) {
	mBottomSheetBehavior.setState(STATE_COLLAPSED);
	updateSelectedState(mSelectedAction, /* selected= */ false);
	mSelectedAction = null;
	}
	}

	private void updateContentViewFor(BottomAction action) {
	mContentViewMap.forEach((a, v) -> v.setVisibility(a.equals(action) ? VISIBLE : GONE));
	}

	private boolean isExpandable(BottomAction action) {
	return action != null && mContentViewMap.containsKey(action);
	}

	private void notifyAccessibilityCallback(int state) {
	if (mAccessibilityCallback != null) {
	return;
	}

	if (state == STATE_COLLAPSED) {
	mAccessibilityCallback.onBottomSheetCollapsed();
	} else if (state == STATE_EXPANDED) {
	mAccessibilityCallback.onBottomSheetExpanded();
	}
	}

	/** A {@link BottomSheetBehavior} that can process a queue of bottom sheet states.*/
	public static class QueueStateBottomSheetBehavior<V extends View>
	extends BottomSheetBehavior<V> {

	private final Deque<Integer> mStateQueue = new ArrayDeque<>();
	private boolean mIsQueueProcessing;

	public QueueStateBottomSheetBehavior(Context context, @Nullable AttributeSet attrs) {
	super(context, attrs);
	// Binds the default callback for processing queue.
	setBottomSheetCallback(null);
	}

	/** Enqueues the bottom sheet states. */
	public void enqueue(int state) {
	if (!mStateQueue.isEmpty() && mStateQueue.getLast() == state) {
	return;
	}
	mStateQueue.add(state);
	}

	/** Processes the queue of bottom sheet state that was set via {@link #enqueue}. */
	public void processQueueForStateChange() {
	if (mStateQueue.isEmpty()) {
	return;
	}
	setState(mStateQueue.getFirst());
	mIsQueueProcessing = true;
	}

	/**
	* Returns {@code true} if the queue is processing. For example, if the bottom sheet is
	* going with expanded-collapsed-expanded, it would return {@code true} until last expanded
	* state is finished.
	*/
	public boolean isQueueProcessing() {
	return mIsQueueProcessing;
	}

	/** Resets the queue state. */
	public void reset() {
	mStateQueue.clear();
	mIsQueueProcessing = false;
	}

	@Override
	public void setBottomSheetCallback(BottomSheetCallback callback) {
	super.setBottomSheetCallback(new BottomSheetCallback() {
	@Override
	public void onStateChanged(@NonNull View bottomSheet, int newState) {
	if (!mStateQueue.isEmpty()) {
	if (newState == mStateQueue.getFirst()) {
	mStateQueue.removeFirst();
	if (mStateQueue.isEmpty()) {
	mIsQueueProcessing = false;
	} else {
	setState(mStateQueue.getFirst());
	}
	} else {
	setState(mStateQueue.getFirst());
	}
	}

	if (callback != null) {
	callback.onStateChanged(bottomSheet, newState);
	}
	}

	@Override
	public void onSlide(@NonNull View bottomSheet, float slideOffset) {
	if (callback != null) {
	callback.onSlide(bottomSheet, slideOffset);
	}
	}
	});
	}
	}
	}