car/src/main/java/androidx/car/widget/ActionBar.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.widget;

 import static java.lang.annotation.RetentionPolicy.SOURCE;

 import android.content.Context;
 import android.content.res.TypedArray;
 import android.graphics.drawable.Drawable;
 import androidx.annotation.DrawableRes;
 import androidx.annotation.IntDef;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 import androidx.interpolator.view.animation.FastOutSlowInInterpolator;
 import android.transition.ChangeBounds;
 import android.transition.Fade;
 import android.transition.TransitionManager;
 import android.transition.TransitionSet;
 import android.util.AttributeSet;
 import android.util.SparseArray;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;
 import android.widget.ImageButton;
 import android.widget.LinearLayout;
 import android.widget.RelativeLayout;
 import android.widget.Space;

 import java.lang.annotation.Retention;
 import java.util.Locale;

 import androidx.car.R;

 /**
  * An actions panel with three distinctive zones:
  * <ul>
  * <li>Main control: located in the bottom center it shows a highlighted icon and a circular
  * progress bar.
  * <li>Secondary controls: these are displayed at the left and at the right of the main control.
  * <li>Overflow controls: these are displayed at the left and at the right of the secondary controls
  * (if the space allows) and on the additional space if the panel is expanded.
  * </ul>
  */
 public class ActionBar extends RelativeLayout {
     private static final String TAG = "ActionBar";

     // ActionBar container
     private ViewGroup mActionBarWrapper;
     // Rows container
     private ViewGroup mRowsContainer;
     // All slots in this action bar where 0 is the bottom-start corner of the matrix, and
     // mNumColumns * nNumRows - 1 is the top-end corner
     private FrameLayout[] mSlots;
     /** Views to set in particular {@link SlotPosition}s */
     private final SparseArray<View> mFixedViews = new SparseArray<>();
     // View to be used for the expand/collapse action
     private @Nullable View mExpandCollapseView;
     // Default expand/collapse view to use one is not provided.
     private View mDefaultExpandCollapseView;
     // Number of rows in actual use. This is the number of extra rows that will be displayed when
     // the action bar is expanded
     private int mNumExtraRowsInUse;
     // Whether the action bar is expanded or not.
     private boolean mIsExpanded;
     // Views to accomodate in the slots.
     private @Nullable View[] mViews;
     // Number of columns of slots to use.
     private int mNumColumns;
     // Maximum number of rows to use.
     private int mNumRows;

     @Retention(SOURCE)
     @IntDef({SLOT_MAIN, SLOT_LEFT, SLOT_RIGHT, SLOT_EXPAND_COLLAPSE})
     public @interface SlotPosition {}

     /** Slot used for main actions {@link ActionBar}, usually at the bottom center */
     public static final int SLOT_MAIN = 0;
     /** Slot used to host 'move left', 'rewind', 'previous' or similar secondary actions,
      * usually at the left of the main action on the bottom row */
     public static final int SLOT_LEFT = 1;
     /** Slot used to host 'move right', 'fast-forward', 'next' or similar secondary actions,
      * usually at the right of the main action on the bottom row */
     public static final int SLOT_RIGHT = 2;
     /** Slot reserved for the expand/collapse button */
     public static final int SLOT_EXPAND_COLLAPSE = 3;

     // Minimum number of columns supported
     private static final int MIN_COLUMNS = 3;
     // Weight for the spacers used at the start and end of each slots row.
     private static final float SPACERS_WEIGHT = 0.5f;

     public ActionBar(Context context) {
         super(context);
         init(context, null, 0, 0);
     }

     public ActionBar(Context context, AttributeSet attrs) {
         super(context, attrs);
         init(context, attrs, 0, 0);
     }

     public ActionBar(Context context, AttributeSet attrs, int defStyleAttrs) {
         super(context, attrs, defStyleAttrs);
         init(context, attrs, defStyleAttrs, 0);
     }

     public ActionBar(Context context, AttributeSet attrs, int defStyleAttrs, int defStyleRes) {
         super(context, attrs, defStyleAttrs, defStyleRes);
         init(context, attrs, defStyleAttrs, defStyleRes);
     }

     private void init(Context context, AttributeSet attrs, int defStyleAttrs, int defStyleRes) {
         inflate(context, R.layout.action_bar, this);

         TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ActionBar,
                 defStyleAttrs, defStyleRes);
         mNumColumns = Math.max(ta.getInteger(R.styleable.ActionBar_columns, MIN_COLUMNS),
                 MIN_COLUMNS);
         ta.recycle();

         mActionBarWrapper = findViewById(R.id.action_bar_wrapper);
         mRowsContainer = findViewById(R.id.rows_container);
         mNumRows = mRowsContainer.getChildCount();
         mSlots = new FrameLayout[mNumColumns * mNumRows];

         for (int i = 0; i < mNumRows; i++) {
             // Slots are reserved in reverse order (first slots are in the bottom row)
             ViewGroup mRow = (ViewGroup) mRowsContainer.getChildAt(mNumRows - i - 1);
             // Inflate space on the left
             Space space = new Space(context);
             mRow.addView(space);
             space.setLayoutParams(new LinearLayout.LayoutParams(0,
                     ViewGroup.LayoutParams.MATCH_PARENT, SPACERS_WEIGHT));
             // Inflate necessary number of columns
             for (int j = 0; j < mNumColumns; j++) {
                 int pos = i * mNumColumns + j;
                 mSlots[pos] = (FrameLayout) inflate(context, R.layout.action_bar_slot, null);
                 mSlots[pos].setLayoutParams(new LinearLayout.LayoutParams(0,
                         ViewGroup.LayoutParams.MATCH_PARENT, 1f));
                 mRow.addView(mSlots[pos]);
             }
             // Inflate space on the right
             space = new Space(context);
             mRow.addView(space);
             space.setLayoutParams(new LinearLayout.LayoutParams(0,
                     ViewGroup.LayoutParams.MATCH_PARENT, SPACERS_WEIGHT));
         }

         mDefaultExpandCollapseView = createIconButton(context, R.drawable.ic_overflow);
         mDefaultExpandCollapseView.setContentDescription(context.getString(
                 R.string.action_bar_expand_collapse_button));
         mDefaultExpandCollapseView.setOnClickListener(v -> onExpandCollapse());
     }

     /**
      * Returns an index in the {@link #mSlots} array, given a well-known slot position.
      */
     private int getSlotIndex(@SlotPosition int slotPosition) {
         switch (slotPosition) {
             case SLOT_MAIN:
                 return mNumColumns / 2;
             case SLOT_LEFT:
                 return mNumColumns < 3 ? -1 : (mNumColumns / 2) - 1;
             case SLOT_RIGHT:
                 return mNumColumns < 2 ? -1 : (mNumColumns / 2) + 1;
             case SLOT_EXPAND_COLLAPSE:
                 return mNumColumns - 1;
             default:
                 throw new IllegalArgumentException("Unknown position: " + slotPosition);
         }
     }

     /**
      * Sets or clears the view to be displayed at a particular position.
      *
      * @param view view to be displayed, or null to leave the position available.
      * @param slotPosition position to update
      */
     public void setView(@Nullable View view, @SlotPosition int slotPosition) {
         if (view != null) {
             mFixedViews.put(slotPosition, view);
         } else {
             mFixedViews.remove(slotPosition);
         }
         updateViewsLayout();
     }

     /**
      * Sets the view to use for the expand/collapse action. If not provided, a default
      * {@link ImageButton} will be used. The provided {@link View} should be able be able to display
      * changes in the "activated" state appropriately.
      *
      * @param view {@link View} to use for the expand/collapse action.
      */
     public void setExpandCollapseView(@NonNull View view) {
         mExpandCollapseView = view;
         mExpandCollapseView.setOnClickListener(v -> onExpandCollapse());
         updateViewsLayout();
     }

     private View getExpandCollapseView() {
         return mExpandCollapseView != null ? mExpandCollapseView : mDefaultExpandCollapseView;
     }

     private ImageButton createIconButton(Context context, @DrawableRes int iconResId) {
         ImageButton button = (ImageButton) inflate(context, R.layout.action_bar_button, null);
         Drawable icon = context.getDrawable(iconResId);
         button.setImageDrawable(icon);
         return button;
     }

     /**
      * Sets the views to include in each available slot of the action bar. Slots will be filled from
      * start to end (i.e: left to right) and from bottom to top. If more views than available slots
      * are provided, all extra views will be ignored.
      *
      * @param views array of views to include in each available slot.
      */
     public void setViews(@Nullable View[] views) {
         mViews = views;
         updateViewsLayout();
     }

     private void updateViewsLayout() {
         // Prepare an array of positions taken
         int totalSlots = mSlots.length;
         View[] slotViews = new View[totalSlots];

         // Take all known positions
         for (int i = 0; i < mFixedViews.size(); i++) {
             int index = getSlotIndex(mFixedViews.keyAt(i));
             if (index >= 0 && index < slotViews.length) {
                 slotViews[index] = mFixedViews.valueAt(i);
             }
         }

         // Set all views using both the fixed and flexible positions
         int expandCollapseIndex = getSlotIndex(SLOT_EXPAND_COLLAPSE);
         int lastUsedIndex = 0;
         int viewsIndex = 0;
         for (int i = 0; i < totalSlots; i++) {
             View viewToUse = null;

             if (slotViews[i] != null) {
                 // If there is a view assigned for this slot, use it.
                 viewToUse = slotViews[i];
             } else if (i == expandCollapseIndex && mViews != null
                     && viewsIndex < mViews.length - 1) {
                 // If this is the expand/collapse slot, use the corresponding view
                 viewToUse = getExpandCollapseView();
             } else if (mViews != null && viewsIndex < mViews.length) {
                 // Otherwise, if the slot is not reserved, and if we still have views to assign,
                 // take one and assign it to this slot.
                 viewToUse = mViews[viewsIndex];
                 viewsIndex++;
             }
             setView(viewToUse, mSlots[i]);
             if (viewToUse != null) {
                 lastUsedIndex = i;
             }
         }

         mNumExtraRowsInUse = lastUsedIndex / mNumColumns;
     }

     private void setView(@Nullable View view, FrameLayout container) {
         container.removeAllViews();
         if (view != null) {
             container.addView(view);
             container.setVisibility(VISIBLE);
             view.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                     ViewGroup.LayoutParams.MATCH_PARENT, Gravity.CENTER));
         } else {
             container.setVisibility(INVISIBLE);
         }
     }

     private void onExpandCollapse() {
         mIsExpanded = !mIsExpanded;
         mSlots[getSlotIndex(SLOT_EXPAND_COLLAPSE)].setActivated(mIsExpanded);

         int animationDuration = getContext().getResources().getInteger(mIsExpanded
                 ? R.integer.car_action_bar_expand_anim_duration
                 : R.integer.car_action_bar_collapse_anim_duration);
         TransitionSet set = new TransitionSet()
                 .addTransition(new ChangeBounds())
                 .addTransition(new Fade())
                 .setDuration(animationDuration)
                 .setInterpolator(new FastOutSlowInInterpolator());
         TransitionManager.beginDelayedTransition(mActionBarWrapper, set);
         for (int i = 0; i < mNumExtraRowsInUse; i++) {
             mRowsContainer.getChildAt(i).setVisibility(mIsExpanded ? View.VISIBLE : View.GONE);
         }
     }

     /**
      * Returns the view assigned to the given row and column, after layout.
      *
      * @param rowIdx row index from 0 being the top row, and {@link #mNumRows{ -1 being the bottom
      * row.
      * @param colIdx column index from 0 on start (left), to {@link #mNumColumns} on end (right)
      */
     @VisibleForTesting
     @Nullable
     View getViewAt(int rowIdx, int colIdx) {
         if (rowIdx < 0 || rowIdx > mRowsContainer.getChildCount()) {
             throw new IllegalArgumentException(String.format((Locale) null,
                     "Row index out of range (requested: %d, max: %d)",
                     rowIdx, mRowsContainer.getChildCount()));
         }
         if (colIdx < 0 || colIdx > mNumColumns) {
             throw new IllegalArgumentException(String.format((Locale) null,
                     "Column index out of range (requested: %d, max: %d)",
                     colIdx, mNumColumns));
         }
         FrameLayout slot = (FrameLayout) ((LinearLayout) mRowsContainer.getChildAt(rowIdx))
                 .getChildAt(colIdx + 1);
         return slot.getChildCount() > 0 ? slot.getChildAt(0) : null;
     }
 }
	/*
	* 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.widget;

	import static java.lang.annotation.RetentionPolicy.SOURCE;

	import android.content.Context;
	import android.content.res.TypedArray;
	import android.graphics.drawable.Drawable;
	import androidx.annotation.DrawableRes;
	import androidx.annotation.IntDef;
	import androidx.annotation.NonNull;
	import androidx.annotation.Nullable;
	import androidx.annotation.VisibleForTesting;
	import androidx.interpolator.view.animation.FastOutSlowInInterpolator;
	import android.transition.ChangeBounds;
	import android.transition.Fade;
	import android.transition.TransitionManager;
	import android.transition.TransitionSet;
	import android.util.AttributeSet;
	import android.util.SparseArray;
	import android.view.Gravity;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.FrameLayout;
	import android.widget.ImageButton;
	import android.widget.LinearLayout;
	import android.widget.RelativeLayout;
	import android.widget.Space;

	import java.lang.annotation.Retention;
	import java.util.Locale;

	import androidx.car.R;

	/**
	* An actions panel with three distinctive zones:
	* <ul>
	* <li>Main control: located in the bottom center it shows a highlighted icon and a circular
	* progress bar.
	* <li>Secondary controls: these are displayed at the left and at the right of the main control.
	* <li>Overflow controls: these are displayed at the left and at the right of the secondary controls
	* (if the space allows) and on the additional space if the panel is expanded.
	* </ul>
	*/
	public class ActionBar extends RelativeLayout {
	private static final String TAG = "ActionBar";

	// ActionBar container
	private ViewGroup mActionBarWrapper;
	// Rows container
	private ViewGroup mRowsContainer;
	// All slots in this action bar where 0 is the bottom-start corner of the matrix, and
	// mNumColumns * nNumRows - 1 is the top-end corner
	private FrameLayout[] mSlots;
	/** Views to set in particular {@link SlotPosition}s */
	private final SparseArray<View> mFixedViews = new SparseArray<>();
	// View to be used for the expand/collapse action
	private @Nullable View mExpandCollapseView;
	// Default expand/collapse view to use one is not provided.
	private View mDefaultExpandCollapseView;
	// Number of rows in actual use. This is the number of extra rows that will be displayed when
	// the action bar is expanded
	private int mNumExtraRowsInUse;
	// Whether the action bar is expanded or not.
	private boolean mIsExpanded;
	// Views to accomodate in the slots.
	private @Nullable View[] mViews;
	// Number of columns of slots to use.
	private int mNumColumns;
	// Maximum number of rows to use.
	private int mNumRows;

	@Retention(SOURCE)
	@IntDef({SLOT_MAIN, SLOT_LEFT, SLOT_RIGHT, SLOT_EXPAND_COLLAPSE})
	public @interface SlotPosition {}

	/** Slot used for main actions {@link ActionBar}, usually at the bottom center */
	public static final int SLOT_MAIN = 0;
	/** Slot used to host 'move left', 'rewind', 'previous' or similar secondary actions,
	* usually at the left of the main action on the bottom row */
	public static final int SLOT_LEFT = 1;
	/** Slot used to host 'move right', 'fast-forward', 'next' or similar secondary actions,
	* usually at the right of the main action on the bottom row */
	public static final int SLOT_RIGHT = 2;
	/** Slot reserved for the expand/collapse button */
	public static final int SLOT_EXPAND_COLLAPSE = 3;

	// Minimum number of columns supported
	private static final int MIN_COLUMNS = 3;
	// Weight for the spacers used at the start and end of each slots row.
	private static final float SPACERS_WEIGHT = 0.5f;

	public ActionBar(Context context) {
	super(context);
	init(context, null, 0, 0);
	}

	public ActionBar(Context context, AttributeSet attrs) {
	super(context, attrs);
	init(context, attrs, 0, 0);
	}

	public ActionBar(Context context, AttributeSet attrs, int defStyleAttrs) {
	super(context, attrs, defStyleAttrs);
	init(context, attrs, defStyleAttrs, 0);
	}

	public ActionBar(Context context, AttributeSet attrs, int defStyleAttrs, int defStyleRes) {
	super(context, attrs, defStyleAttrs, defStyleRes);
	init(context, attrs, defStyleAttrs, defStyleRes);
	}

	private void init(Context context, AttributeSet attrs, int defStyleAttrs, int defStyleRes) {
	inflate(context, R.layout.action_bar, this);

	TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ActionBar,
	defStyleAttrs, defStyleRes);
	mNumColumns = Math.max(ta.getInteger(R.styleable.ActionBar_columns, MIN_COLUMNS),
	MIN_COLUMNS);
	ta.recycle();

	mActionBarWrapper = findViewById(R.id.action_bar_wrapper);
	mRowsContainer = findViewById(R.id.rows_container);
	mNumRows = mRowsContainer.getChildCount();
	mSlots = new FrameLayout[mNumColumns * mNumRows];

	for (int i = 0; i < mNumRows; i++) {
	// Slots are reserved in reverse order (first slots are in the bottom row)
	ViewGroup mRow = (ViewGroup) mRowsContainer.getChildAt(mNumRows - i - 1);
	// Inflate space on the left
	Space space = new Space(context);
	mRow.addView(space);
	space.setLayoutParams(new LinearLayout.LayoutParams(0,
	ViewGroup.LayoutParams.MATCH_PARENT, SPACERS_WEIGHT));
	// Inflate necessary number of columns
	for (int j = 0; j < mNumColumns; j++) {
	int pos = i * mNumColumns + j;
	mSlots[pos] = (FrameLayout) inflate(context, R.layout.action_bar_slot, null);
	mSlots[pos].setLayoutParams(new LinearLayout.LayoutParams(0,
	ViewGroup.LayoutParams.MATCH_PARENT, 1f));
	mRow.addView(mSlots[pos]);
	}
	// Inflate space on the right
	space = new Space(context);
	mRow.addView(space);
	space.setLayoutParams(new LinearLayout.LayoutParams(0,
	ViewGroup.LayoutParams.MATCH_PARENT, SPACERS_WEIGHT));
	}

	mDefaultExpandCollapseView = createIconButton(context, R.drawable.ic_overflow);
	mDefaultExpandCollapseView.setContentDescription(context.getString(
	R.string.action_bar_expand_collapse_button));
	mDefaultExpandCollapseView.setOnClickListener(v -> onExpandCollapse());
	}

	/**
	* Returns an index in the {@link #mSlots} array, given a well-known slot position.
	*/
	private int getSlotIndex(@SlotPosition int slotPosition) {
	switch (slotPosition) {
	case SLOT_MAIN:
	return mNumColumns / 2;
	case SLOT_LEFT:
	return mNumColumns < 3 ? -1 : (mNumColumns / 2) - 1;
	case SLOT_RIGHT:
	return mNumColumns < 2 ? -1 : (mNumColumns / 2) + 1;
	case SLOT_EXPAND_COLLAPSE:
	return mNumColumns - 1;
	default:
	throw new IllegalArgumentException("Unknown position: " + slotPosition);
	}
	}

	/**
	* Sets or clears the view to be displayed at a particular position.
	*
	* @param view view to be displayed, or null to leave the position available.
	* @param slotPosition position to update
	*/
	public void setView(@Nullable View view, @SlotPosition int slotPosition) {
	if (view != null) {
	mFixedViews.put(slotPosition, view);
	} else {
	mFixedViews.remove(slotPosition);
	}
	updateViewsLayout();
	}

	/**
	* Sets the view to use for the expand/collapse action. If not provided, a default
	* {@link ImageButton} will be used. The provided {@link View} should be able be able to display
	* changes in the "activated" state appropriately.
	*
	* @param view {@link View} to use for the expand/collapse action.
	*/
	public void setExpandCollapseView(@NonNull View view) {
	mExpandCollapseView = view;
	mExpandCollapseView.setOnClickListener(v -> onExpandCollapse());
	updateViewsLayout();
	}

	private View getExpandCollapseView() {
	return mExpandCollapseView != null ? mExpandCollapseView : mDefaultExpandCollapseView;
	}

	private ImageButton createIconButton(Context context, @DrawableRes int iconResId) {
	ImageButton button = (ImageButton) inflate(context, R.layout.action_bar_button, null);
	Drawable icon = context.getDrawable(iconResId);
	button.setImageDrawable(icon);
	return button;
	}

	/**
	* Sets the views to include in each available slot of the action bar. Slots will be filled from
	* start to end (i.e: left to right) and from bottom to top. If more views than available slots
	* are provided, all extra views will be ignored.
	*
	* @param views array of views to include in each available slot.
	*/
	public void setViews(@Nullable View[] views) {
	mViews = views;
	updateViewsLayout();
	}

	private void updateViewsLayout() {
	// Prepare an array of positions taken
	int totalSlots = mSlots.length;
	View[] slotViews = new View[totalSlots];

	// Take all known positions
	for (int i = 0; i < mFixedViews.size(); i++) {
	int index = getSlotIndex(mFixedViews.keyAt(i));
	if (index >= 0 && index < slotViews.length) {
	slotViews[index] = mFixedViews.valueAt(i);
	}
	}

	// Set all views using both the fixed and flexible positions
	int expandCollapseIndex = getSlotIndex(SLOT_EXPAND_COLLAPSE);
	int lastUsedIndex = 0;
	int viewsIndex = 0;
	for (int i = 0; i < totalSlots; i++) {
	View viewToUse = null;

	if (slotViews[i] != null) {
	// If there is a view assigned for this slot, use it.
	viewToUse = slotViews[i];
	} else if (i == expandCollapseIndex && mViews != null
	&& viewsIndex < mViews.length - 1) {
	// If this is the expand/collapse slot, use the corresponding view
	viewToUse = getExpandCollapseView();
	} else if (mViews != null && viewsIndex < mViews.length) {
	// Otherwise, if the slot is not reserved, and if we still have views to assign,
	// take one and assign it to this slot.
	viewToUse = mViews[viewsIndex];
	viewsIndex++;
	}
	setView(viewToUse, mSlots[i]);
	if (viewToUse != null) {
	lastUsedIndex = i;
	}
	}

	mNumExtraRowsInUse = lastUsedIndex / mNumColumns;
	}

	private void setView(@Nullable View view, FrameLayout container) {
	container.removeAllViews();
	if (view != null) {
	container.addView(view);
	container.setVisibility(VISIBLE);
	view.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
	ViewGroup.LayoutParams.MATCH_PARENT, Gravity.CENTER));
	} else {
	container.setVisibility(INVISIBLE);
	}
	}

	private void onExpandCollapse() {
	mIsExpanded = !mIsExpanded;
	mSlots[getSlotIndex(SLOT_EXPAND_COLLAPSE)].setActivated(mIsExpanded);

	int animationDuration = getContext().getResources().getInteger(mIsExpanded
	? R.integer.car_action_bar_expand_anim_duration
	: R.integer.car_action_bar_collapse_anim_duration);
	TransitionSet set = new TransitionSet()
	.addTransition(new ChangeBounds())
	.addTransition(new Fade())
	.setDuration(animationDuration)
	.setInterpolator(new FastOutSlowInInterpolator());
	TransitionManager.beginDelayedTransition(mActionBarWrapper, set);
	for (int i = 0; i < mNumExtraRowsInUse; i++) {
	mRowsContainer.getChildAt(i).setVisibility(mIsExpanded ? View.VISIBLE : View.GONE);
	}
	}

	/**
	* Returns the view assigned to the given row and column, after layout.
	*
	* @param rowIdx row index from 0 being the top row, and {@link #mNumRows{ -1 being the bottom
	* row.
	* @param colIdx column index from 0 on start (left), to {@link #mNumColumns} on end (right)
	*/
	@VisibleForTesting
	@Nullable
	View getViewAt(int rowIdx, int colIdx) {
	if (rowIdx < 0 \|\| rowIdx > mRowsContainer.getChildCount()) {
	throw new IllegalArgumentException(String.format((Locale) null,
	"Row index out of range (requested: %d, max: %d)",
	rowIdx, mRowsContainer.getChildCount()));
	}
	if (colIdx < 0 \|\| colIdx > mNumColumns) {
	throw new IllegalArgumentException(String.format((Locale) null,
	"Column index out of range (requested: %d, max: %d)",
	colIdx, mNumColumns));
	}
	FrameLayout slot = (FrameLayout) ((LinearLayout) mRowsContainer.getChildAt(rowIdx))
	.getChildAt(colIdx + 1);
	return slot.getChildCount() > 0 ? slot.getChildAt(0) : null;
	}
	}