src/com/android/wallpaper/util/FullScreenAnimation.java - platform/packages/apps/WallpaperPicker2 - Git at Google

 /*
  * Copyright (C) 2021 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.util;

 import android.animation.Animator;
 import android.animation.AnimatorSet;
 import android.animation.ObjectAnimator;
 import android.animation.ValueAnimator;
 import android.content.res.TypedArray;
 import android.graphics.Insets;
 import android.graphics.Point;
 import android.graphics.Rect;
 import android.view.Gravity;
 import android.view.SurfaceView;
 import android.view.View;
 import android.view.WindowInsets;
 import android.widget.Button;
 import android.widget.FrameLayout;
 import android.widget.ImageButton;
 import android.widget.TextView;
 import android.widget.Toolbar;

 import androidx.cardview.widget.CardView;

 import com.android.wallpaper.R;
 import com.android.wallpaper.picker.TouchForwardingLayout;

 /**
  * A class storing information about a preview fragment's full-screen layout.
  *
  * Used for {@code ImagePreviewFragment} and {@code LivePreviewFragment}.
  */
 public class FullScreenAnimation {

     private final View mView;
     private final TouchForwardingLayout mTouchForwardingLayout;
     private final SurfaceView mWorkspaceSurface;
     private boolean mIsFullScreen = false;
     private boolean mShowInFullScreen = false;

     private boolean mScaleIsSet = false;
     private boolean mWorkspaceVisibility = true;
     private float mOffsetY;
     private float mScale;
     private float mDefaultRadius;
     private int mWorkspaceWidth;
     private int mWorkspaceHeight;
     private float mBottomActionBarTranslation;
     private float mFullScreenButtonsTranslation;
     private int mStatusBarHeight;
     private int mNavigationBarHeight;
     private FullScreenStatusListener mFullScreenStatusListener;

     private static final float HIDE_ICONS_TOP_RATIO = 0.2f;

     private boolean mIsHomeSelected = true;

     /**
      * Options for the full-screen text color.
      *
      * {@code DEFAULT} represents the default text color.
      * {@code DARK} represents a text color that is dark, and should be used when the wallpaper
      *              supports dark text.
      * {@code LIGHT} represents a text color that is light, and should be used when the wallpaper
      *               does not support dark text.
      */
     public enum FullScreenTextColor {
         DEFAULT,
         DARK,
         LIGHT
     }

     FullScreenTextColor mFullScreenTextColor = FullScreenTextColor.DEFAULT;
     private int mCurrentTextColor;

     /** Callback for full screen status. */
     public interface FullScreenStatusListener {
         /** Gets called at animation end when full screen status gets changed. */
         void onFullScreenStatusChange(boolean isFullScreen);
     }

     /**
      * Constructor.
      *
      * @param view The view containing all relevant UI elements. Equal to {@code mRootView}.
      */
     public FullScreenAnimation(View view) {
         mView = view;
         mTouchForwardingLayout = view.findViewById(R.id.touch_forwarding_layout);
         mWorkspaceSurface = view.findViewById(R.id.workspace_surface);
         mCurrentTextColor = ResourceUtils.getColorAttr(
                 view.getContext(),
                 android.R.attr.textColorPrimary);
     }

     /**
      * Returns if the preview layout is currently in full screen.
      *
      * @return whether the preview layout is currently in full screen.
      */
     public boolean isFullScreen() {
         return mIsFullScreen;
     }

     /**
      * Informs this object whether the home tab is selected.
      *
      * Used to determine the visibility of {@code lock_screen_preview_container}.
      *
      * @param isHomeSelected whether the home tab is selected.
      */
     public void setIsHomeSelected(boolean isHomeSelected) {
         mIsHomeSelected = isHomeSelected;
     }

     /**
      * Informs this object whether the full screen is separate activity.
      *
      * Used to determine the height of workspace.
      *
      * @param isShowInFullScreen whether the full screen is separate activity.
      */
     public void setShowInFullScreen(boolean isShowInFullScreen) {
         mShowInFullScreen = isShowInFullScreen;
     }

     /**
      * Returns the height of status bar.
      *
      * @return height of status bar.
      */
     public int getStatusBarHeight() {
         return mStatusBarHeight;
     }

     private int getNavigationBarHeight() {
         return mNavigationBarHeight;
     }

     private int getAttributeDimension(int resId) {
         final TypedArray attributes = mView.getContext().getTheme().obtainStyledAttributes(
                 new int[]{resId});
         int dimension = attributes.getDimensionPixelSize(0, 0);
         attributes.recycle();
         return dimension;
     }

     private void setViewMargins(int viewId, float marginTop, float marginBottom,
             boolean separatedTabs) {
         FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(
                 FrameLayout.LayoutParams.MATCH_PARENT,
                 separatedTabs ? FrameLayout.LayoutParams.WRAP_CONTENT
                         : FrameLayout.LayoutParams.MATCH_PARENT);

         layoutParams.setMargins(0, Math.round(marginTop), 0, Math.round(marginBottom));

         if (separatedTabs) {
             layoutParams.gravity = Gravity.BOTTOM;
         }

         mView.findViewById(viewId).setLayoutParams(layoutParams);
     }

     /** Sets a {@param listener} to listen full screen state changes. */
     public void setFullScreenStatusListener(FullScreenStatusListener listener) {
         mFullScreenStatusListener = listener;
     }

     /**
      * Informs the {@code FullScreenAnimation} object about the window insets of the current
      * window.
      *
      * Called by a {@code View.OnApplyWindowInsetsListener} defined in {@code PreviewFragment}.
      *
      * @param windowInsets the window insets of the current window.
      */
     public void setWindowInsets(WindowInsets windowInsets) {
         Insets insets = windowInsets.getInsetsIgnoringVisibility(
                 WindowInsets.Type.systemBars()
         );

         mStatusBarHeight = insets.top;
         mNavigationBarHeight = insets.bottom;
     }

     /**
      * Place UI elements in the correct locations.
      *
      * Takes status bar and navigation bar into account.
      * @param view view is used to show preview fragment.
      */
     public void placeViews(View view) {
         // If is already full screen we do not do anything here.
         if (mIsFullScreen) {
             return;
         }
         if (mShowInFullScreen) {
             View container = view.findViewById(R.id.container);
             container.setPadding(0, 0, 0, 0);
             setViewMargins(R.id.screen_preview_layout, 0, 0, false);
         } else {
             setViewMargins(R.id.screen_preview_layout,
                     (float) getStatusBarHeight() + mView.findViewById(
                             R.id.preview_header).getPaddingBottom(),
                     getNavigationBarHeight()
                             + mView.getResources().getDimension(R.dimen.bottom_actions_height)
                             + mView.getResources().getDimension(R.dimen.separated_tabs_height),
                     false);
         }
         setViewMargins(R.id.bottom_action_bar_container,
                 0,
                 getNavigationBarHeight(),
                 false);
         setViewMargins(R.id.separated_tabs_container,
                 0,
                 getNavigationBarHeight()
                         + mView.getResources().getDimension(R.dimen.bottom_actions_height),
                 true);
         ensureToolbarIsCorrectlyLocated();
     }

     /**
      * Ensures that the bottom action bar is in the correct location.
      *
      * Called by {@code onBottomActionBarReady}, so that the bottom action bar is correctly located
      * when it is redrawn.
      */
     public void ensureBottomActionBarIsCorrectlyLocated() {
         float targetTranslation = mIsFullScreen ? mBottomActionBarTranslation : 0;
         mView.findViewById(R.id.bottom_actionbar).setTranslationY(targetTranslation);
     }

     /**
      * Ensures that the toolbar is in the correct location.
      *
      * Called by {@code placeViews}, {@code ImageWallpaperColorThemePreviewFragment#updateToolBar},
      * and @{code LiveWallpaperColorThemePreviewFragment#updateToolBar}, so that the toolbar is
      * correctly located when it is redrawn.
      */
     public void ensureToolbarIsCorrectlyLocated() {
         FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(
                 FrameLayout.LayoutParams.MATCH_PARENT,
                 FrameLayout.LayoutParams.MATCH_PARENT);

         layoutParams.setMargins(0, getStatusBarHeight(), 0, 0);
         mView.findViewById(R.id.section_header_container).setLayoutParams(layoutParams);
     }

     /**
      * Ensures that the text and the navigation button on the toolbar is given the correct color.
      *
      * Called by {@code updateToolBar}.
      */
     public void ensureToolbarIsCorrectlyColored() {
         TextView textView = mView.findViewById(R.id.custom_toolbar_title);
         if (textView != null) {
             textView.setTextColor(mCurrentTextColor);
         }

         Toolbar toolbar = mView.findViewById(R.id.toolbar);
         // It may be null because there's no back arrow in some cases. For example: no back arrow
         // for Photos launching case.
         ImageButton button = (ImageButton) toolbar.getNavigationView();
         if (button != null) {
             button.setColorFilter(mCurrentTextColor);
         }
     }

     /**
      * Sets the text color used for the "Preview" caption in full screen mode.
      *
      * @param fullScreenTextColor The desired color for the "Preview" caption in full screen mode.
      */
     public void setFullScreenTextColor(FullScreenTextColor fullScreenTextColor) {
         mFullScreenTextColor = fullScreenTextColor;

         animateColor(mIsFullScreen);
     }

     /**
      * Sets the visibility of the workspace surface (containing icons from the home screen) and
      * the elements unique to the lock screen (date and time).
      *
      * Called when the "Hide UI Preview" button is clicked.
      *
      * @param visible {@code true} if the icons should be shown;
      *                {@code false} if they should be hidden.
      */
     public void setWorkspaceVisibility(boolean visible) {
         // Not using [setVisibility], because it creates a "jump".
         if (visible) {
             mWorkspaceSurface.setClipBounds(new Rect(
                     0,
                     Math.round(mWorkspaceHeight * HIDE_ICONS_TOP_RATIO),
                     mWorkspaceWidth,
                     mShowInFullScreen ? mWorkspaceHeight : mWorkspaceHeight + Math.round(
                             mFullScreenButtonsTranslation / mScale)));
             mView.findViewById(R.id.lock_screen_preview_container).setVisibility(View.VISIBLE);
         } else {
             mWorkspaceSurface.setClipBounds(new Rect(
                     mWorkspaceWidth - 1,
                     mWorkspaceHeight - 1,
                     mWorkspaceWidth,
                     mWorkspaceHeight));
             mView.findViewById(R.id.lock_screen_preview_container).setVisibility(View.INVISIBLE);
         }
         if (mIsHomeSelected) {
             mView.findViewById(R.id.lock_screen_preview_container).setVisibility(View.INVISIBLE);
         }
         mWorkspaceVisibility = visible;
     }

     /**
      * Returns the visibility of the workspace surface (containing icons from the home screen).
      *
      * @return the visibility of the workspace surface.
      */
     public boolean getWorkspaceVisibility() {
         return mWorkspaceVisibility;
     }

     private void animateColor(boolean toFullScreen) {
         TextView textView = mView.findViewById(R.id.custom_toolbar_title);

         int targetColor;
         if (!toFullScreen || mFullScreenTextColor == FullScreenTextColor.DEFAULT) {
             targetColor = ResourceUtils.getColorAttr(
                     mView.getContext(),
                     android.R.attr.textColorPrimary);
         } else if (mFullScreenTextColor == FullScreenTextColor.DARK) {
             targetColor = mView.getContext().getColor(android.R.color.black);
         } else {
             targetColor = mView.getContext().getColor(android.R.color.white);
         }

         if (targetColor == mCurrentTextColor) {
             return;
         }

         Toolbar toolbar = mView.findViewById(R.id.toolbar);
         ImageButton button = (ImageButton) toolbar.getNavigationView();

         ValueAnimator colorAnimator = ValueAnimator.ofArgb(mCurrentTextColor, targetColor);
         colorAnimator.addUpdateListener(animation -> {
             int color = (int) animation.getAnimatedValue();
             if (textView != null) {
                 textView.setTextColor(color);
             }
             // It may be null because there's no back arrow in some cases. For example: no back
             // arrow for Photos launching case.
             if (button != null) {
                 button.setColorFilter(color);
             }
         });
         colorAnimator.start();

         mCurrentTextColor = targetColor;
     }

     /**
      * Animates the layout to or from fullscreen.
      *
      * @param toFullScreen {@code true} if animating into the full screen layout;
      *                     {@code false} if animating out of the full screen layout.
      */
     public void startAnimation(boolean toFullScreen) {
         // If there is no need to animate, return.
         if (toFullScreen == mIsFullScreen) {
             return;
         }

         // If the scale is not set, compute the location and size of frame layout.
         if (!mScaleIsSet) {
             int[] loc = new int[2];
             mTouchForwardingLayout.getLocationInWindow(loc);

             ScreenSizeCalculator screenSizeCalculator = ScreenSizeCalculator.getInstance();
             Point screenSize = screenSizeCalculator.getScreenSize(mView.getDisplay());
             int screenWidth = screenSize.x;
             int screenHeight = screenSize.y;

             mOffsetY = (float) (screenHeight / 2.0
                     - (loc[1] + mTouchForwardingLayout.getHeight() / 2.0));

             mScale = Math.max(
                     screenWidth / (float) mTouchForwardingLayout.getWidth(),
                     screenHeight / (float) mTouchForwardingLayout.getHeight());

             mDefaultRadius = ((CardView) mWorkspaceSurface.getParent()).getRadius();

             mWorkspaceSurface.setEnableSurfaceClipping(true);

             mWorkspaceWidth = mWorkspaceSurface.getWidth();
             mWorkspaceHeight = mWorkspaceSurface.getHeight();

             mBottomActionBarTranslation = getNavigationBarHeight()
                     + mView.getResources().getDimension(R.dimen.bottom_actions_height)
                     + mView.getResources().getDimension(R.dimen.separated_tabs_height);

             mFullScreenButtonsTranslation = -(getNavigationBarHeight()
                     + mView.getResources().getDimension(
                             R.dimen.fullscreen_preview_button_margin_bottom)
                     + mView.getResources().getDimension(R.dimen.separated_tabs_height));

             mScaleIsSet = true;
         }

         // Perform animations.

         // Rounding animation.
         // Animated version of ((CardView) mWorkspaceSurface.getParent()).setRadius(0);
         float fromRadius = toFullScreen ? mDefaultRadius : 0f;
         float toRadius = toFullScreen ? 0f : mDefaultRadius;

         ValueAnimator animationRounding = ValueAnimator.ofFloat(fromRadius, toRadius);
         animationRounding.addUpdateListener(animation -> {
             ((CardView) mWorkspaceSurface.getParent()).setRadius(
                     (float) animation.getAnimatedValue());
         });

         // Animation to hide some of the home screen icons.
         float fromTop = toFullScreen ? 0f : HIDE_ICONS_TOP_RATIO;
         float toTop = toFullScreen ? HIDE_ICONS_TOP_RATIO : 0f;
         float fromBottom = toFullScreen ? 0 : mFullScreenButtonsTranslation / mScale;
         float toBottom = toFullScreen ? mFullScreenButtonsTranslation / mScale : 0;

         ValueAnimator animationHide = ValueAnimator.ofFloat(0f, 1f);
         animationHide.addUpdateListener(animation -> {
             float t = (float) animation.getAnimatedValue();
             float top = fromTop + t * (toTop - fromTop);
             float bottom = fromBottom + t * (toBottom - fromBottom);
             mWorkspaceSurface.setClipBounds(new Rect(
                     0,
                     Math.round(mWorkspaceHeight * top),
                     mWorkspaceWidth,
                     mShowInFullScreen ? mWorkspaceHeight : mWorkspaceHeight + Math.round(bottom)));
         });

         // Other animations.
         float scale = toFullScreen ? mScale : 1f;
         float offsetY = toFullScreen ? mOffsetY : 0f;
         float bottomActionBarTranslation = toFullScreen ? mBottomActionBarTranslation : 0;
         float fullScreenButtonsTranslation = toFullScreen ? mFullScreenButtonsTranslation : 0;
         View frameLayout = mView.findViewById(R.id.screen_preview_layout);

         AnimatorSet animatorSet = new AnimatorSet();
         animatorSet.playTogether(
                 ObjectAnimator.ofFloat(frameLayout, "scaleX", scale),
                 ObjectAnimator.ofFloat(frameLayout, "scaleY", scale),
                 ObjectAnimator.ofFloat(frameLayout, "translationY", offsetY),
                 ObjectAnimator.ofFloat(mView.findViewById(R.id.bottom_actionbar),
                         "translationY", bottomActionBarTranslation),
                 ObjectAnimator.ofFloat(mView.findViewById(R.id.separated_tabs_container),
                         "translationY", bottomActionBarTranslation),
                 ObjectAnimator.ofFloat(mView.findViewById(R.id.fullscreen_buttons_container),
                         "translationY", fullScreenButtonsTranslation),
                 animationRounding,
                 animationHide
         );
         animatorSet.addListener(new Animator.AnimatorListener() {
             @Override
             public void onAnimationCancel(Animator animator) {}

             @Override
             public void onAnimationEnd(Animator animator) {
                 if (mFullScreenStatusListener != null) {
                     mFullScreenStatusListener.onFullScreenStatusChange(toFullScreen);
                 }
             }

             @Override
             public void onAnimationRepeat(Animator animator) {}

             @Override
             public void onAnimationStart(Animator animator) {}
         });
         animatorSet.start();

         animateColor(toFullScreen);

         // Changes appearances of some elements.
         mWorkspaceVisibility = true;

         if (toFullScreen) {
             ((Button) mView.findViewById(R.id.hide_ui_preview_button)).setText(
                     R.string.hide_ui_preview_text
             );
         }

         mView.findViewById(R.id.lock_screen_preview_container).setVisibility(View.VISIBLE);
         if (mIsHomeSelected) {
             mView.findViewById(R.id.lock_screen_preview_container)
                     .setVisibility(View.INVISIBLE);
         }

         mIsFullScreen = toFullScreen;
     }
 }
	/*
	* Copyright (C) 2021 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.util;

	import android.animation.Animator;
	import android.animation.AnimatorSet;
	import android.animation.ObjectAnimator;
	import android.animation.ValueAnimator;
	import android.content.res.TypedArray;
	import android.graphics.Insets;
	import android.graphics.Point;
	import android.graphics.Rect;
	import android.view.Gravity;
	import android.view.SurfaceView;
	import android.view.View;
	import android.view.WindowInsets;
	import android.widget.Button;
	import android.widget.FrameLayout;
	import android.widget.ImageButton;
	import android.widget.TextView;
	import android.widget.Toolbar;

	import androidx.cardview.widget.CardView;

	import com.android.wallpaper.R;
	import com.android.wallpaper.picker.TouchForwardingLayout;

	/**
	* A class storing information about a preview fragment's full-screen layout.
	*
	* Used for {@code ImagePreviewFragment} and {@code LivePreviewFragment}.
	*/
	public class FullScreenAnimation {

	private final View mView;
	private final TouchForwardingLayout mTouchForwardingLayout;
	private final SurfaceView mWorkspaceSurface;
	private boolean mIsFullScreen = false;
	private boolean mShowInFullScreen = false;

	private boolean mScaleIsSet = false;
	private boolean mWorkspaceVisibility = true;
	private float mOffsetY;
	private float mScale;
	private float mDefaultRadius;
	private int mWorkspaceWidth;
	private int mWorkspaceHeight;
	private float mBottomActionBarTranslation;
	private float mFullScreenButtonsTranslation;
	private int mStatusBarHeight;
	private int mNavigationBarHeight;
	private FullScreenStatusListener mFullScreenStatusListener;

	private static final float HIDE_ICONS_TOP_RATIO = 0.2f;

	private boolean mIsHomeSelected = true;

	/**
	* Options for the full-screen text color.
	*
	* {@code DEFAULT} represents the default text color.
	* {@code DARK} represents a text color that is dark, and should be used when the wallpaper
	* supports dark text.
	* {@code LIGHT} represents a text color that is light, and should be used when the wallpaper
	* does not support dark text.
	*/
	public enum FullScreenTextColor {
	DEFAULT,
	DARK,
	LIGHT
	}

	FullScreenTextColor mFullScreenTextColor = FullScreenTextColor.DEFAULT;
	private int mCurrentTextColor;

	/** Callback for full screen status. */
	public interface FullScreenStatusListener {
	/** Gets called at animation end when full screen status gets changed. */
	void onFullScreenStatusChange(boolean isFullScreen);
	}

	/**
	* Constructor.
	*
	* @param view The view containing all relevant UI elements. Equal to {@code mRootView}.
	*/
	public FullScreenAnimation(View view) {
	mView = view;
	mTouchForwardingLayout = view.findViewById(R.id.touch_forwarding_layout);
	mWorkspaceSurface = view.findViewById(R.id.workspace_surface);
	mCurrentTextColor = ResourceUtils.getColorAttr(
	view.getContext(),
	android.R.attr.textColorPrimary);
	}

	/**
	* Returns if the preview layout is currently in full screen.
	*
	* @return whether the preview layout is currently in full screen.
	*/
	public boolean isFullScreen() {
	return mIsFullScreen;
	}

	/**
	* Informs this object whether the home tab is selected.
	*
	* Used to determine the visibility of {@code lock_screen_preview_container}.
	*
	* @param isHomeSelected whether the home tab is selected.
	*/
	public void setIsHomeSelected(boolean isHomeSelected) {
	mIsHomeSelected = isHomeSelected;
	}

	/**
	* Informs this object whether the full screen is separate activity.
	*
	* Used to determine the height of workspace.
	*
	* @param isShowInFullScreen whether the full screen is separate activity.
	*/
	public void setShowInFullScreen(boolean isShowInFullScreen) {
	mShowInFullScreen = isShowInFullScreen;
	}

	/**
	* Returns the height of status bar.
	*
	* @return height of status bar.
	*/
	public int getStatusBarHeight() {
	return mStatusBarHeight;
	}

	private int getNavigationBarHeight() {
	return mNavigationBarHeight;
	}

	private int getAttributeDimension(int resId) {
	final TypedArray attributes = mView.getContext().getTheme().obtainStyledAttributes(
	new int[]{resId});
	int dimension = attributes.getDimensionPixelSize(0, 0);
	attributes.recycle();
	return dimension;
	}

	private void setViewMargins(int viewId, float marginTop, float marginBottom,
	boolean separatedTabs) {
	FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(
	FrameLayout.LayoutParams.MATCH_PARENT,
	separatedTabs ? FrameLayout.LayoutParams.WRAP_CONTENT
	: FrameLayout.LayoutParams.MATCH_PARENT);

	layoutParams.setMargins(0, Math.round(marginTop), 0, Math.round(marginBottom));

	if (separatedTabs) {
	layoutParams.gravity = Gravity.BOTTOM;
	}

	mView.findViewById(viewId).setLayoutParams(layoutParams);
	}

	/** Sets a {@param listener} to listen full screen state changes. */
	public void setFullScreenStatusListener(FullScreenStatusListener listener) {
	mFullScreenStatusListener = listener;
	}

	/**
	* Informs the {@code FullScreenAnimation} object about the window insets of the current
	* window.
	*
	* Called by a {@code View.OnApplyWindowInsetsListener} defined in {@code PreviewFragment}.
	*
	* @param windowInsets the window insets of the current window.
	*/
	public void setWindowInsets(WindowInsets windowInsets) {
	Insets insets = windowInsets.getInsetsIgnoringVisibility(
	WindowInsets.Type.systemBars()
	);

	mStatusBarHeight = insets.top;
	mNavigationBarHeight = insets.bottom;
	}

	/**
	* Place UI elements in the correct locations.
	*
	* Takes status bar and navigation bar into account.
	* @param view view is used to show preview fragment.
	*/
	public void placeViews(View view) {
	// If is already full screen we do not do anything here.
	if (mIsFullScreen) {
	return;
	}
	if (mShowInFullScreen) {
	View container = view.findViewById(R.id.container);
	container.setPadding(0, 0, 0, 0);
	setViewMargins(R.id.screen_preview_layout, 0, 0, false);
	} else {
	setViewMargins(R.id.screen_preview_layout,
	(float) getStatusBarHeight() + mView.findViewById(
	R.id.preview_header).getPaddingBottom(),
	getNavigationBarHeight()
	+ mView.getResources().getDimension(R.dimen.bottom_actions_height)
	+ mView.getResources().getDimension(R.dimen.separated_tabs_height),
	false);
	}
	setViewMargins(R.id.bottom_action_bar_container,
	0,
	getNavigationBarHeight(),
	false);
	setViewMargins(R.id.separated_tabs_container,
	0,
	getNavigationBarHeight()
	+ mView.getResources().getDimension(R.dimen.bottom_actions_height),
	true);
	ensureToolbarIsCorrectlyLocated();
	}

	/**
	* Ensures that the bottom action bar is in the correct location.
	*
	* Called by {@code onBottomActionBarReady}, so that the bottom action bar is correctly located
	* when it is redrawn.
	*/
	public void ensureBottomActionBarIsCorrectlyLocated() {
	float targetTranslation = mIsFullScreen ? mBottomActionBarTranslation : 0;
	mView.findViewById(R.id.bottom_actionbar).setTranslationY(targetTranslation);
	}

	/**
	* Ensures that the toolbar is in the correct location.
	*
	* Called by {@code placeViews}, {@code ImageWallpaperColorThemePreviewFragment#updateToolBar},
	* and @{code LiveWallpaperColorThemePreviewFragment#updateToolBar}, so that the toolbar is
	* correctly located when it is redrawn.
	*/
	public void ensureToolbarIsCorrectlyLocated() {
	FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(
	FrameLayout.LayoutParams.MATCH_PARENT,
	FrameLayout.LayoutParams.MATCH_PARENT);

	layoutParams.setMargins(0, getStatusBarHeight(), 0, 0);
	mView.findViewById(R.id.section_header_container).setLayoutParams(layoutParams);
	}

	/**
	* Ensures that the text and the navigation button on the toolbar is given the correct color.
	*
	* Called by {@code updateToolBar}.
	*/
	public void ensureToolbarIsCorrectlyColored() {
	TextView textView = mView.findViewById(R.id.custom_toolbar_title);
	if (textView != null) {
	textView.setTextColor(mCurrentTextColor);
	}

	Toolbar toolbar = mView.findViewById(R.id.toolbar);
	// It may be null because there's no back arrow in some cases. For example: no back arrow
	// for Photos launching case.
	ImageButton button = (ImageButton) toolbar.getNavigationView();
	if (button != null) {
	button.setColorFilter(mCurrentTextColor);
	}
	}

	/**
	* Sets the text color used for the "Preview" caption in full screen mode.
	*
	* @param fullScreenTextColor The desired color for the "Preview" caption in full screen mode.
	*/
	public void setFullScreenTextColor(FullScreenTextColor fullScreenTextColor) {
	mFullScreenTextColor = fullScreenTextColor;

	animateColor(mIsFullScreen);
	}

	/**
	* Sets the visibility of the workspace surface (containing icons from the home screen) and
	* the elements unique to the lock screen (date and time).
	*
	* Called when the "Hide UI Preview" button is clicked.
	*
	* @param visible {@code true} if the icons should be shown;
	* {@code false} if they should be hidden.
	*/
	public void setWorkspaceVisibility(boolean visible) {
	// Not using [setVisibility], because it creates a "jump".
	if (visible) {
	mWorkspaceSurface.setClipBounds(new Rect(
	0,
	Math.round(mWorkspaceHeight * HIDE_ICONS_TOP_RATIO),
	mWorkspaceWidth,
	mShowInFullScreen ? mWorkspaceHeight : mWorkspaceHeight + Math.round(
	mFullScreenButtonsTranslation / mScale)));
	mView.findViewById(R.id.lock_screen_preview_container).setVisibility(View.VISIBLE);
	} else {
	mWorkspaceSurface.setClipBounds(new Rect(
	mWorkspaceWidth - 1,
	mWorkspaceHeight - 1,
	mWorkspaceWidth,
	mWorkspaceHeight));
	mView.findViewById(R.id.lock_screen_preview_container).setVisibility(View.INVISIBLE);
	}
	if (mIsHomeSelected) {
	mView.findViewById(R.id.lock_screen_preview_container).setVisibility(View.INVISIBLE);
	}
	mWorkspaceVisibility = visible;
	}

	/**
	* Returns the visibility of the workspace surface (containing icons from the home screen).
	*
	* @return the visibility of the workspace surface.
	*/
	public boolean getWorkspaceVisibility() {
	return mWorkspaceVisibility;
	}

	private void animateColor(boolean toFullScreen) {
	TextView textView = mView.findViewById(R.id.custom_toolbar_title);

	int targetColor;
	if (!toFullScreen \|\| mFullScreenTextColor == FullScreenTextColor.DEFAULT) {
	targetColor = ResourceUtils.getColorAttr(
	mView.getContext(),
	android.R.attr.textColorPrimary);
	} else if (mFullScreenTextColor == FullScreenTextColor.DARK) {
	targetColor = mView.getContext().getColor(android.R.color.black);
	} else {
	targetColor = mView.getContext().getColor(android.R.color.white);
	}

	if (targetColor == mCurrentTextColor) {
	return;
	}

	Toolbar toolbar = mView.findViewById(R.id.toolbar);
	ImageButton button = (ImageButton) toolbar.getNavigationView();

	ValueAnimator colorAnimator = ValueAnimator.ofArgb(mCurrentTextColor, targetColor);
	colorAnimator.addUpdateListener(animation -> {
	int color = (int) animation.getAnimatedValue();
	if (textView != null) {
	textView.setTextColor(color);
	}
	// It may be null because there's no back arrow in some cases. For example: no back
	// arrow for Photos launching case.
	if (button != null) {
	button.setColorFilter(color);
	}
	});
	colorAnimator.start();

	mCurrentTextColor = targetColor;
	}

	/**
	* Animates the layout to or from fullscreen.
	*
	* @param toFullScreen {@code true} if animating into the full screen layout;
	* {@code false} if animating out of the full screen layout.
	*/
	public void startAnimation(boolean toFullScreen) {
	// If there is no need to animate, return.
	if (toFullScreen == mIsFullScreen) {
	return;
	}

	// If the scale is not set, compute the location and size of frame layout.
	if (!mScaleIsSet) {
	int[] loc = new int[2];
	mTouchForwardingLayout.getLocationInWindow(loc);

	ScreenSizeCalculator screenSizeCalculator = ScreenSizeCalculator.getInstance();
	Point screenSize = screenSizeCalculator.getScreenSize(mView.getDisplay());
	int screenWidth = screenSize.x;
	int screenHeight = screenSize.y;

	mOffsetY = (float) (screenHeight / 2.0
	- (loc[1] + mTouchForwardingLayout.getHeight() / 2.0));

	mScale = Math.max(
	screenWidth / (float) mTouchForwardingLayout.getWidth(),
	screenHeight / (float) mTouchForwardingLayout.getHeight());

	mDefaultRadius = ((CardView) mWorkspaceSurface.getParent()).getRadius();

	mWorkspaceSurface.setEnableSurfaceClipping(true);

	mWorkspaceWidth = mWorkspaceSurface.getWidth();
	mWorkspaceHeight = mWorkspaceSurface.getHeight();

	mBottomActionBarTranslation = getNavigationBarHeight()
	+ mView.getResources().getDimension(R.dimen.bottom_actions_height)
	+ mView.getResources().getDimension(R.dimen.separated_tabs_height);

	mFullScreenButtonsTranslation = -(getNavigationBarHeight()
	+ mView.getResources().getDimension(
	R.dimen.fullscreen_preview_button_margin_bottom)
	+ mView.getResources().getDimension(R.dimen.separated_tabs_height));

	mScaleIsSet = true;
	}

	// Perform animations.

	// Rounding animation.
	// Animated version of ((CardView) mWorkspaceSurface.getParent()).setRadius(0);
	float fromRadius = toFullScreen ? mDefaultRadius : 0f;
	float toRadius = toFullScreen ? 0f : mDefaultRadius;

	ValueAnimator animationRounding = ValueAnimator.ofFloat(fromRadius, toRadius);
	animationRounding.addUpdateListener(animation -> {
	((CardView) mWorkspaceSurface.getParent()).setRadius(
	(float) animation.getAnimatedValue());
	});

	// Animation to hide some of the home screen icons.
	float fromTop = toFullScreen ? 0f : HIDE_ICONS_TOP_RATIO;
	float toTop = toFullScreen ? HIDE_ICONS_TOP_RATIO : 0f;
	float fromBottom = toFullScreen ? 0 : mFullScreenButtonsTranslation / mScale;
	float toBottom = toFullScreen ? mFullScreenButtonsTranslation / mScale : 0;

	ValueAnimator animationHide = ValueAnimator.ofFloat(0f, 1f);
	animationHide.addUpdateListener(animation -> {
	float t = (float) animation.getAnimatedValue();
	float top = fromTop + t * (toTop - fromTop);
	float bottom = fromBottom + t * (toBottom - fromBottom);
	mWorkspaceSurface.setClipBounds(new Rect(
	0,
	Math.round(mWorkspaceHeight * top),
	mWorkspaceWidth,
	mShowInFullScreen ? mWorkspaceHeight : mWorkspaceHeight + Math.round(bottom)));
	});

	// Other animations.
	float scale = toFullScreen ? mScale : 1f;
	float offsetY = toFullScreen ? mOffsetY : 0f;
	float bottomActionBarTranslation = toFullScreen ? mBottomActionBarTranslation : 0;
	float fullScreenButtonsTranslation = toFullScreen ? mFullScreenButtonsTranslation : 0;
	View frameLayout = mView.findViewById(R.id.screen_preview_layout);

	AnimatorSet animatorSet = new AnimatorSet();
	animatorSet.playTogether(
	ObjectAnimator.ofFloat(frameLayout, "scaleX", scale),
	ObjectAnimator.ofFloat(frameLayout, "scaleY", scale),
	ObjectAnimator.ofFloat(frameLayout, "translationY", offsetY),
	ObjectAnimator.ofFloat(mView.findViewById(R.id.bottom_actionbar),
	"translationY", bottomActionBarTranslation),
	ObjectAnimator.ofFloat(mView.findViewById(R.id.separated_tabs_container),
	"translationY", bottomActionBarTranslation),
	ObjectAnimator.ofFloat(mView.findViewById(R.id.fullscreen_buttons_container),
	"translationY", fullScreenButtonsTranslation),
	animationRounding,
	animationHide
	);
	animatorSet.addListener(new Animator.AnimatorListener() {
	@Override
	public void onAnimationCancel(Animator animator) {}

	@Override
	public void onAnimationEnd(Animator animator) {
	if (mFullScreenStatusListener != null) {
	mFullScreenStatusListener.onFullScreenStatusChange(toFullScreen);
	}
	}

	@Override
	public void onAnimationRepeat(Animator animator) {}

	@Override
	public void onAnimationStart(Animator animator) {}
	});
	animatorSet.start();

	animateColor(toFullScreen);

	// Changes appearances of some elements.
	mWorkspaceVisibility = true;

	if (toFullScreen) {
	((Button) mView.findViewById(R.id.hide_ui_preview_button)).setText(
	R.string.hide_ui_preview_text
	);
	}

	mView.findViewById(R.id.lock_screen_preview_container).setVisibility(View.VISIBLE);
	if (mIsHomeSelected) {
	mView.findViewById(R.id.lock_screen_preview_container)
	.setVisibility(View.INVISIBLE);
	}

	mIsFullScreen = toFullScreen;
	}
	}