src/com/android/wallpaper/picker/ImagePreviewFragment.java - platform/packages/apps/WallpaperPicker2 - Git at Google

 /*
  * Copyright (C) 2019 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.picker;

 import static android.view.View.MeasureSpec.EXACTLY;
 import static android.view.View.MeasureSpec.makeMeasureSpec;

 import static com.android.wallpaper.widget.BottomActionBar.BottomAction.APPLY;
 import static com.android.wallpaper.widget.BottomActionBar.BottomAction.EDIT;
 import static com.android.wallpaper.widget.BottomActionBar.BottomAction.INFORMATION;

 import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.app.Activity;
 import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.Color;
 import android.graphics.Point;
 import android.graphics.PointF;
 import android.graphics.Rect;
 import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.Surface;
 import android.view.SurfaceControlViewHost;
 import android.view.SurfaceHolder;
 import android.view.SurfaceView;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.ImageView;

 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.cardview.widget.CardView;
 import androidx.constraintlayout.widget.ConstraintLayout;
 import androidx.constraintlayout.widget.ConstraintSet;
 import androidx.core.content.ContextCompat;
 import androidx.fragment.app.FragmentActivity;

 import com.android.wallpaper.R;
 import com.android.wallpaper.asset.Asset;
 import com.android.wallpaper.model.WallpaperInfo;
 import com.android.wallpaper.module.WallpaperPersister.Destination;
 import com.android.wallpaper.module.WallpaperPersister.SetWallpaperCallback;
 import com.android.wallpaper.util.ScreenSizeCalculator;
 import com.android.wallpaper.util.SizeCalculator;
 import com.android.wallpaper.util.WallpaperCropUtils;
 import com.android.wallpaper.widget.BottomActionBar;
 import com.android.wallpaper.widget.BottomActionBar.AccessibilityCallback;
 import com.android.wallpaper.widget.LockScreenPreviewer;
 import com.android.wallpaper.widget.WallpaperColorsLoader;
 import com.android.wallpaper.widget.WallpaperInfoView;

 import com.bumptech.glide.Glide;
 import com.bumptech.glide.MemoryCategory;
 import com.davemorrissey.labs.subscaleview.ImageSource;
 import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView;

 import java.util.Locale;

 /**
  * Fragment which displays the UI for previewing an individual static wallpaper and its attribution
  * information.
  */
 public class ImagePreviewFragment extends PreviewFragment {

     private static final float DEFAULT_WALLPAPER_MAX_ZOOM = 8f;

     private final WallpaperSurfaceCallback mWallpaperSurfaceCallback =
             new WallpaperSurfaceCallback();

     private SubsamplingScaleImageView mFullResImageView;
     private Asset mWallpaperAsset;
     private Point mScreenSize;
     private Point mRawWallpaperSize; // Native size of wallpaper image.
     private ImageView mLowResImageView;
     private TouchForwardingLayout mTouchForwardingLayout;
     private ConstraintLayout mContainer;
     private SurfaceView mWorkspaceSurface;
     private WorkspaceSurfaceHolderCallback mWorkspaceSurfaceCallback;
     private SurfaceView mWallpaperSurface;
     private ViewGroup mLockPreviewContainer;
     private LockScreenPreviewer mLockScreenPreviewer;
     private View mTabs;
     private WallpaperInfoView mWallpaperInfoView;
     private View mLock;
     private View mHome;

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         mWallpaperAsset = mWallpaper.getAsset(requireContext().getApplicationContext());
     }

     @Override
     protected int getLayoutResId() {
         return R.layout.fragment_image_preview_v2;
     }

     @Override
     protected int getLoadingIndicatorResId() {
         return R.id.loading_indicator;
     }

     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
             Bundle savedInstanceState) {
         View view = super.onCreateView(inflater, container, savedInstanceState);

         Activity activity = requireActivity();
         mScreenSize = ScreenSizeCalculator.getInstance().getScreenSize(
                 activity.getWindowManager().getDefaultDisplay());

         // TODO: Consider moving some part of this to the base class when live preview is ready.
         view.findViewById(R.id.low_res_image).setVisibility(View.GONE);
         view.findViewById(R.id.full_res_image).setVisibility(View.GONE);
         mLoadingProgressBar.hide();
         mContainer = view.findViewById(R.id.container);
         mTouchForwardingLayout = mContainer.findViewById(R.id.touch_forwarding_layout);

         // Set aspect ratio on the preview card dynamically.
         ConstraintSet set = new ConstraintSet();
         set.clone(mContainer);
         String ratio = String.format(Locale.US, "%d:%d", mScreenSize.x, mScreenSize.y);
         set.setDimensionRatio(mTouchForwardingLayout.getId(), ratio);
         set.applyTo(mContainer);

         mWorkspaceSurface = mContainer.findViewById(R.id.workspace_surface);
         mWorkspaceSurfaceCallback = new WorkspaceSurfaceHolderCallback(mWorkspaceSurface,
                 getContext());
         mWallpaperSurface = mContainer.findViewById(R.id.wallpaper_surface);
         mLockPreviewContainer = mContainer.findViewById(R.id.lock_screen_preview_container);
         mLockScreenPreviewer = new LockScreenPreviewer(getLifecycle(), getActivity(),
                 mLockPreviewContainer);

         mTabs = view.findViewById(R.id.tabs_container);
         mLock = mTabs.findViewById(R.id.lock);
         mHome = mTabs.findViewById(R.id.home);
         mLock.setOnClickListener(v -> updateScreenPreview(/* isHomeSelected= */ false));
         mHome.setOnClickListener(v -> updateScreenPreview(/* isHomeSelected= */ true));

         view.measure(makeMeasureSpec(mScreenSize.x, EXACTLY),
                 makeMeasureSpec(mScreenSize.y, EXACTLY));

         ((CardView) mWorkspaceSurface.getParent())
                 .setRadius(SizeCalculator.getPreviewCornerRadius(
                         activity, mContainer.getMeasuredWidth()));
         renderImageWallpaper();
         renderWorkspaceSurface();
         updateScreenPreview(/* isHomeSelected= */ mViewAsHome);

         // Trim some memory from Glide to make room for the full-size image in this fragment.
         Glide.get(activity).setMemoryCategory(MemoryCategory.LOW);
         setUpLoadingIndicator();
         return view;
     }

     @Override
     public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
         WallpaperColorsLoader.getWallpaperColors(getContext(),
                 mWallpaper.getThumbAsset(getContext()),
                 mLockScreenPreviewer::setColor);
     }

     @Override
     protected boolean isLoaded() {
         return mFullResImageView != null && mFullResImageView.hasImage();
     }

     @Override
     public void onClickOk() {
         FragmentActivity activity = getActivity();
         if (activity != null) {
             activity.finish();
         }
     }

     @Override
     public void onDestroy() {
         super.onDestroy();
         if (mLoadingProgressBar != null) {
             mLoadingProgressBar.hide();
         }
         mFullResImageView.recycle();

         mWallpaperSurfaceCallback.cleanUp();
         mWorkspaceSurfaceCallback.cleanUp();
     }

     @Override
     protected void onBottomActionBarReady(BottomActionBar bottomActionBar) {
         super.onBottomActionBarReady(bottomActionBar);

         mWallpaperInfoView = (WallpaperInfoView)
                 LayoutInflater.from(getContext()).inflate(
                         R.layout.wallpaper_info_view, /* root= */null);
         mBottomActionBar.attachViewToBottomSheetAndBindAction(mWallpaperInfoView, INFORMATION);
         mBottomActionBar.showActionsOnly(INFORMATION, EDIT, APPLY);
         mBottomActionBar.setActionClickListener(EDIT, v ->
                 setEditingEnabled(mBottomActionBar.isActionSelected(EDIT))
         );
         mBottomActionBar.setActionSelectedListener(EDIT, this::setEditingEnabled);
         mBottomActionBar.setActionClickListener(APPLY, this::onSetWallpaperClicked);

         // Update target view's accessibility param since it will be blocked by the bottom sheet
         // when expanded.
         mBottomActionBar.setAccessibilityCallback(new AccessibilityCallback() {
             @Override
             public void onBottomSheetCollapsed() {
                 mContainer.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
                 mTabs.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
             }

             @Override
             public void onBottomSheetExpanded() {
                 mContainer.setImportantForAccessibility(
                         View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
                 mTabs.setImportantForAccessibility(
                         View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
             }
         });

         // Will trigger onActionSelected callback to update the editing state.
         mBottomActionBar.setDefaultSelectedButton(EDIT);
         mBottomActionBar.show();

         mBottomActionBar.disableActions();
         mWallpaperAsset.decodeRawDimensions(getActivity(), dimensions -> {
             if (mBottomActionBar != null) {
                 mBottomActionBar.enableActions();
             }

             // Don't continue loading the wallpaper if the Fragment is detached.
             if (getActivity() == null) {
                 return;
             }

             // Return early and show a dialog if dimensions are null (signaling a decoding error).
             if (dimensions == null) {
                 showLoadWallpaperErrorDialog();
                 return;
             }

             mRawWallpaperSize = dimensions;

             setUpExploreIntentAndLabel(ImagePreviewFragment.this::initFullResView);
         });
     }

     /**
      * Initializes MosaicView by initializing tiling, setting a fallback page bitmap, and
      * initializing a zoom-scroll observer and click listener.
      */
     private void initFullResView() {
         // Minimum scale will only be respected under this scale type.
         mFullResImageView.setMinimumScaleType(SubsamplingScaleImageView.SCALE_TYPE_CUSTOM);
         // When we set a minimum scale bigger than the scale with which the full image is shown,
         // disallow user to pan outside the view we show the wallpaper in.
         mFullResImageView.setPanLimit(SubsamplingScaleImageView.PAN_LIMIT_INSIDE);

         // Set a solid black "page bitmap" so MosaicView draws a black background while waiting
         // for the image to load or a transparent one if a thumbnail already loaded.
         Bitmap backgroundBitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888);
         int preColor = ContextCompat.getColor(getContext(), R.color.fullscreen_preview_background);
         int color = (mLowResImageView.getDrawable() == null) ? preColor : Color.TRANSPARENT;
         backgroundBitmap.setPixel(0, 0, color);
         mFullResImageView.setImage(ImageSource.bitmap(backgroundBitmap));

         // Then set a fallback "page bitmap" to cover the whole MosaicView, which is an actual
         // (lower res) version of the image to be displayed.
         Point targetPageBitmapSize = new Point(mRawWallpaperSize);
         mWallpaperAsset.decodeBitmap(targetPageBitmapSize.x, targetPageBitmapSize.y,
                 pageBitmap -> {
                     // Check that the activity is still around since the decoding task started.
                     if (getActivity() == null) {
                         return;
                     }

                     // Some of these may be null depending on if the Fragment is paused, stopped,
                     // or destroyed.
                     if (mLoadingProgressBar != null) {
                         mLoadingProgressBar.hide();
                     }
                     // The page bitmap may be null if there was a decoding error, so show an
                     // error dialog.
                     if (pageBitmap == null) {
                         showLoadWallpaperErrorDialog();
                         return;
                     }
                     if (mFullResImageView != null) {
                         // Set page bitmap.
                         mFullResImageView.setImage(ImageSource.bitmap(pageBitmap));

                         setDefaultWallpaperZoomAndScroll();
                         crossFadeInMosaicView();
                     }
                     getActivity().invalidateOptionsMenu();

                     if (mWallpaperInfoView != null && mWallpaper != null) {
                         mWallpaperInfoView.populateWallpaperInfo(mWallpaper, mActionLabel,
                                 mExploreIntent, this::onExploreClicked);
                     }
                 });
     }

     /**
      * Makes the MosaicView visible with an alpha fade-in animation while fading out the loading
      * indicator.
      */
     private void crossFadeInMosaicView() {
         long shortAnimationDuration = getResources().getInteger(
                 android.R.integer.config_shortAnimTime);

         mFullResImageView.setAlpha(0f);
         mFullResImageView.animate()
                 .alpha(1f)
                 .setDuration(shortAnimationDuration)
                 .setListener(new AnimatorListenerAdapter() {
                     @Override
                     public void onAnimationEnd(Animator animation) {
                         // Clear the thumbnail bitmap reference to save memory since it's no longer
                         // visible.
                         if (mLowResImageView != null) {
                             mLowResImageView.setImageBitmap(null);
                         }
                     }
                 });

         mLoadingProgressBar.animate()
                 .alpha(0f)
                 .setDuration(shortAnimationDuration)
                 .setListener(new AnimatorListenerAdapter() {
                     @Override
                     public void onAnimationEnd(Animator animation) {
                         if (mLoadingProgressBar != null) {
                             mLoadingProgressBar.hide();
                         }
                     }
                 });
     }

     /**
      * Sets the default wallpaper zoom and scroll position based on a "crop surface" (with extra
      * width to account for parallax) superimposed on the screen. Shows as much of the wallpaper as
      * possible on the crop surface and align screen to crop surface such that the default preview
      * matches what would be seen by the user in the left-most home screen.
      *
      * <p>This method is called once in the Fragment lifecycle after the wallpaper asset has loaded
      * and rendered to the layout.
      */
     private void setDefaultWallpaperZoomAndScroll() {
         // Determine minimum zoom to fit maximum visible area of wallpaper on crop surface.
         int cropWidth = mWorkspaceSurface.getMeasuredWidth();
         int cropHeight = mWorkspaceSurface.getMeasuredHeight();
         Point crop = new Point(cropWidth, cropHeight);
         Rect visibleRawWallpaperRect =
                 WallpaperCropUtils.calculateVisibleRect(mRawWallpaperSize, crop);

         final PointF centerPosition = WallpaperCropUtils.calculateDefaultCenter(requireContext(),
                 mRawWallpaperSize, visibleRawWallpaperRect);

         Point visibleRawWallpaperSize = new Point(visibleRawWallpaperRect.width(),
                 visibleRawWallpaperRect.height());

         final float defaultWallpaperZoom = WallpaperCropUtils.calculateMinZoom(
                 visibleRawWallpaperSize, crop);
         final float minWallpaperZoom = defaultWallpaperZoom;


         // Set min wallpaper zoom and max zoom on MosaicView widget.
         mFullResImageView.setMaxScale(Math.max(DEFAULT_WALLPAPER_MAX_ZOOM, defaultWallpaperZoom));
         mFullResImageView.setMinScale(minWallpaperZoom);

         // Set center to composite positioning between scaled wallpaper and screen.
         mFullResImageView.setScaleAndCenter(minWallpaperZoom, centerPosition);
     }

     private Rect calculateCropRect() {
         float wallpaperZoom = mFullResImageView.getScale();
         Context context = requireContext().getApplicationContext();

         Rect visibleFileRect = new Rect();
         mFullResImageView.visibleFileRect(visibleFileRect);

         int cropWidth = mWorkspaceSurface.getMeasuredWidth();
         int cropHeight = mWorkspaceSurface.getMeasuredHeight();
         Point hostViewSize = new Point(cropWidth, cropHeight);
         Rect cropRect = WallpaperCropUtils.calculateCropRect(context, hostViewSize,
                 hostViewSize, mRawWallpaperSize, visibleFileRect, wallpaperZoom);
         WallpaperCropUtils.adjustCropRect(context, cropRect, false /* zoomIn */);
         return cropRect;
     }

     @Override
     protected void setCurrentWallpaper(@Destination int destination) {
         mWallpaperSetter.setCurrentWallpaper(getActivity(), mWallpaper, mWallpaperAsset,
                 destination, mFullResImageView.getScale(), calculateCropRect(),
                 new SetWallpaperCallback() {
                     @Override
                     public void onSuccess(WallpaperInfo wallpaperInfo) {
                         finishActivity(/* success= */ true);
                     }

                     @Override
                     public void onError(@Nullable Throwable throwable) {
                         showSetWallpaperErrorDialog(destination);
                     }
                 });
     }

     private void renderWorkspaceSurface() {
         mWorkspaceSurface.setZOrderMediaOverlay(true);
         mWorkspaceSurface.getHolder().addCallback(mWorkspaceSurfaceCallback);
     }

     private void renderImageWallpaper() {
         mWallpaperSurface.getHolder().addCallback(mWallpaperSurfaceCallback);
     }

     private class WallpaperSurfaceCallback implements SurfaceHolder.Callback {

         private Surface mLastSurface;
         private SurfaceControlViewHost mHost;

         @Override
         public void surfaceCreated(SurfaceHolder holder) {
             if (mLastSurface != holder.getSurface()) {
                 mLastSurface = holder.getSurface();
                 if (mFullResImageView != null) {
                     mFullResImageView.recycle();
                 }
                 View wallpaperPreviewContainer = LayoutInflater.from(getContext()).inflate(
                         R.layout.fullscreen_wallpaper_preview, null);
                 mFullResImageView = wallpaperPreviewContainer.findViewById(R.id.full_res_image);
                 mLowResImageView = wallpaperPreviewContainer.findViewById(R.id.low_res_image);
                 // Load a low-res placeholder image if there's a thumbnail available from the asset
                 // that can be shown to the user more quickly than the full-sized image.
                 if (mWallpaperAsset.hasLowResDataSource()) {
                     Activity activity = requireActivity();
                     mWallpaperAsset.loadLowResDrawable(activity, mLowResImageView, Color.BLACK,
                             new WallpaperPreviewBitmapTransformation(
                                     activity.getApplicationContext(), isRtl()));
                 }
                 wallpaperPreviewContainer.measure(
                         makeMeasureSpec(mWallpaperSurface.getWidth(), EXACTLY),
                         makeMeasureSpec(mWallpaperSurface.getHeight(), EXACTLY));
                 wallpaperPreviewContainer.layout(0, 0, mWallpaperSurface.getWidth(),
                         mWallpaperSurface.getHeight());
                 mTouchForwardingLayout.setTargetView(mFullResImageView);

                 cleanUp();
                 mHost = new SurfaceControlViewHost(getContext(),
                         getContext().getDisplay(), mWallpaperSurface.getHostToken());
                 mHost.setView(wallpaperPreviewContainer, wallpaperPreviewContainer.getWidth(),
                         wallpaperPreviewContainer.getHeight());
                 mWallpaperSurface.setChildSurfacePackage(mHost.getSurfacePackage());
             }
         }

         @Override
         public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { }

         @Override
         public void surfaceDestroyed(SurfaceHolder holder) { }

         public void cleanUp() {
             if (mHost != null) {
                 mHost.release();
                 mHost = null;
             }
         }
     };

     private void setEditingEnabled(boolean enabled) {
         mTouchForwardingLayout.setForwardingEnabled(enabled);
     }

     private void updateScreenPreview(boolean isHomeSelected) {
         mHome.setSelected(isHomeSelected);
         mLock.setSelected(!isHomeSelected);
         mWorkspaceSurface.setVisibility(isHomeSelected ? View.VISIBLE : View.INVISIBLE);
         mLockPreviewContainer.setVisibility(isHomeSelected ? View.INVISIBLE : View.VISIBLE);
     }
 }
	/*
	* Copyright (C) 2019 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.picker;

	import static android.view.View.MeasureSpec.EXACTLY;
	import static android.view.View.MeasureSpec.makeMeasureSpec;

	import static com.android.wallpaper.widget.BottomActionBar.BottomAction.APPLY;
	import static com.android.wallpaper.widget.BottomActionBar.BottomAction.EDIT;
	import static com.android.wallpaper.widget.BottomActionBar.BottomAction.INFORMATION;

	import android.animation.Animator;
	import android.animation.AnimatorListenerAdapter;
	import android.app.Activity;
	import android.content.Context;
	import android.graphics.Bitmap;
	import android.graphics.Color;
	import android.graphics.Point;
	import android.graphics.PointF;
	import android.graphics.Rect;
	import android.os.Bundle;
	import android.view.LayoutInflater;
	import android.view.Surface;
	import android.view.SurfaceControlViewHost;
	import android.view.SurfaceHolder;
	import android.view.SurfaceView;
	import android.view.View;
	import android.view.ViewGroup;
	import android.widget.ImageView;

	import androidx.annotation.NonNull;
	import androidx.annotation.Nullable;
	import androidx.cardview.widget.CardView;
	import androidx.constraintlayout.widget.ConstraintLayout;
	import androidx.constraintlayout.widget.ConstraintSet;
	import androidx.core.content.ContextCompat;
	import androidx.fragment.app.FragmentActivity;

	import com.android.wallpaper.R;
	import com.android.wallpaper.asset.Asset;
	import com.android.wallpaper.model.WallpaperInfo;
	import com.android.wallpaper.module.WallpaperPersister.Destination;
	import com.android.wallpaper.module.WallpaperPersister.SetWallpaperCallback;
	import com.android.wallpaper.util.ScreenSizeCalculator;
	import com.android.wallpaper.util.SizeCalculator;
	import com.android.wallpaper.util.WallpaperCropUtils;
	import com.android.wallpaper.widget.BottomActionBar;
	import com.android.wallpaper.widget.BottomActionBar.AccessibilityCallback;
	import com.android.wallpaper.widget.LockScreenPreviewer;
	import com.android.wallpaper.widget.WallpaperColorsLoader;
	import com.android.wallpaper.widget.WallpaperInfoView;

	import com.bumptech.glide.Glide;
	import com.bumptech.glide.MemoryCategory;
	import com.davemorrissey.labs.subscaleview.ImageSource;
	import com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView;

	import java.util.Locale;

	/**
	* Fragment which displays the UI for previewing an individual static wallpaper and its attribution
	* information.
	*/
	public class ImagePreviewFragment extends PreviewFragment {

	private static final float DEFAULT_WALLPAPER_MAX_ZOOM = 8f;

	private final WallpaperSurfaceCallback mWallpaperSurfaceCallback =
	new WallpaperSurfaceCallback();

	private SubsamplingScaleImageView mFullResImageView;
	private Asset mWallpaperAsset;
	private Point mScreenSize;
	private Point mRawWallpaperSize; // Native size of wallpaper image.
	private ImageView mLowResImageView;
	private TouchForwardingLayout mTouchForwardingLayout;
	private ConstraintLayout mContainer;
	private SurfaceView mWorkspaceSurface;
	private WorkspaceSurfaceHolderCallback mWorkspaceSurfaceCallback;
	private SurfaceView mWallpaperSurface;
	private ViewGroup mLockPreviewContainer;
	private LockScreenPreviewer mLockScreenPreviewer;
	private View mTabs;
	private WallpaperInfoView mWallpaperInfoView;
	private View mLock;
	private View mHome;

	@Override
	public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	mWallpaperAsset = mWallpaper.getAsset(requireContext().getApplicationContext());
	}

	@Override
	protected int getLayoutResId() {
	return R.layout.fragment_image_preview_v2;
	}

	@Override
	protected int getLoadingIndicatorResId() {
	return R.id.loading_indicator;
	}

	@Override
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
	Bundle savedInstanceState) {
	View view = super.onCreateView(inflater, container, savedInstanceState);

	Activity activity = requireActivity();
	mScreenSize = ScreenSizeCalculator.getInstance().getScreenSize(
	activity.getWindowManager().getDefaultDisplay());

	// TODO: Consider moving some part of this to the base class when live preview is ready.
	view.findViewById(R.id.low_res_image).setVisibility(View.GONE);
	view.findViewById(R.id.full_res_image).setVisibility(View.GONE);
	mLoadingProgressBar.hide();
	mContainer = view.findViewById(R.id.container);
	mTouchForwardingLayout = mContainer.findViewById(R.id.touch_forwarding_layout);

	// Set aspect ratio on the preview card dynamically.
	ConstraintSet set = new ConstraintSet();
	set.clone(mContainer);
	String ratio = String.format(Locale.US, "%d:%d", mScreenSize.x, mScreenSize.y);
	set.setDimensionRatio(mTouchForwardingLayout.getId(), ratio);
	set.applyTo(mContainer);

	mWorkspaceSurface = mContainer.findViewById(R.id.workspace_surface);
	mWorkspaceSurfaceCallback = new WorkspaceSurfaceHolderCallback(mWorkspaceSurface,
	getContext());
	mWallpaperSurface = mContainer.findViewById(R.id.wallpaper_surface);
	mLockPreviewContainer = mContainer.findViewById(R.id.lock_screen_preview_container);
	mLockScreenPreviewer = new LockScreenPreviewer(getLifecycle(), getActivity(),
	mLockPreviewContainer);

	mTabs = view.findViewById(R.id.tabs_container);
	mLock = mTabs.findViewById(R.id.lock);
	mHome = mTabs.findViewById(R.id.home);
	mLock.setOnClickListener(v -> updateScreenPreview(/* isHomeSelected= */ false));
	mHome.setOnClickListener(v -> updateScreenPreview(/* isHomeSelected= */ true));

	view.measure(makeMeasureSpec(mScreenSize.x, EXACTLY),
	makeMeasureSpec(mScreenSize.y, EXACTLY));

	((CardView) mWorkspaceSurface.getParent())
	.setRadius(SizeCalculator.getPreviewCornerRadius(
	activity, mContainer.getMeasuredWidth()));
	renderImageWallpaper();
	renderWorkspaceSurface();
	updateScreenPreview(/* isHomeSelected= */ mViewAsHome);

	// Trim some memory from Glide to make room for the full-size image in this fragment.
	Glide.get(activity).setMemoryCategory(MemoryCategory.LOW);
	setUpLoadingIndicator();
	return view;
	}

	@Override
	public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
	super.onViewCreated(view, savedInstanceState);
	WallpaperColorsLoader.getWallpaperColors(getContext(),
	mWallpaper.getThumbAsset(getContext()),
	mLockScreenPreviewer::setColor);
	}

	@Override
	protected boolean isLoaded() {
	return mFullResImageView != null && mFullResImageView.hasImage();
	}

	@Override
	public void onClickOk() {
	FragmentActivity activity = getActivity();
	if (activity != null) {
	activity.finish();
	}
	}

	@Override
	public void onDestroy() {
	super.onDestroy();
	if (mLoadingProgressBar != null) {
	mLoadingProgressBar.hide();
	}
	mFullResImageView.recycle();

	mWallpaperSurfaceCallback.cleanUp();
	mWorkspaceSurfaceCallback.cleanUp();
	}

	@Override
	protected void onBottomActionBarReady(BottomActionBar bottomActionBar) {
	super.onBottomActionBarReady(bottomActionBar);

	mWallpaperInfoView = (WallpaperInfoView)
	LayoutInflater.from(getContext()).inflate(
	R.layout.wallpaper_info_view, /* root= */null);
	mBottomActionBar.attachViewToBottomSheetAndBindAction(mWallpaperInfoView, INFORMATION);
	mBottomActionBar.showActionsOnly(INFORMATION, EDIT, APPLY);
	mBottomActionBar.setActionClickListener(EDIT, v ->
	setEditingEnabled(mBottomActionBar.isActionSelected(EDIT))
	);
	mBottomActionBar.setActionSelectedListener(EDIT, this::setEditingEnabled);
	mBottomActionBar.setActionClickListener(APPLY, this::onSetWallpaperClicked);

	// Update target view's accessibility param since it will be blocked by the bottom sheet
	// when expanded.
	mBottomActionBar.setAccessibilityCallback(new AccessibilityCallback() {
	@Override
	public void onBottomSheetCollapsed() {
	mContainer.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
	mTabs.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
	}

	@Override
	public void onBottomSheetExpanded() {
	mContainer.setImportantForAccessibility(
	View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
	mTabs.setImportantForAccessibility(
	View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS);
	}
	});

	// Will trigger onActionSelected callback to update the editing state.
	mBottomActionBar.setDefaultSelectedButton(EDIT);
	mBottomActionBar.show();

	mBottomActionBar.disableActions();
	mWallpaperAsset.decodeRawDimensions(getActivity(), dimensions -> {
	if (mBottomActionBar != null) {
	mBottomActionBar.enableActions();
	}

	// Don't continue loading the wallpaper if the Fragment is detached.
	if (getActivity() == null) {
	return;
	}

	// Return early and show a dialog if dimensions are null (signaling a decoding error).
	if (dimensions == null) {
	showLoadWallpaperErrorDialog();
	return;
	}

	mRawWallpaperSize = dimensions;

	setUpExploreIntentAndLabel(ImagePreviewFragment.this::initFullResView);
	});
	}

	/**
	* Initializes MosaicView by initializing tiling, setting a fallback page bitmap, and
	* initializing a zoom-scroll observer and click listener.
	*/
	private void initFullResView() {
	// Minimum scale will only be respected under this scale type.
	mFullResImageView.setMinimumScaleType(SubsamplingScaleImageView.SCALE_TYPE_CUSTOM);
	// When we set a minimum scale bigger than the scale with which the full image is shown,
	// disallow user to pan outside the view we show the wallpaper in.
	mFullResImageView.setPanLimit(SubsamplingScaleImageView.PAN_LIMIT_INSIDE);

	// Set a solid black "page bitmap" so MosaicView draws a black background while waiting
	// for the image to load or a transparent one if a thumbnail already loaded.
	Bitmap backgroundBitmap = Bitmap.createBitmap(1, 1, Bitmap.Config.ARGB_8888);
	int preColor = ContextCompat.getColor(getContext(), R.color.fullscreen_preview_background);
	int color = (mLowResImageView.getDrawable() == null) ? preColor : Color.TRANSPARENT;
	backgroundBitmap.setPixel(0, 0, color);
	mFullResImageView.setImage(ImageSource.bitmap(backgroundBitmap));

	// Then set a fallback "page bitmap" to cover the whole MosaicView, which is an actual
	// (lower res) version of the image to be displayed.
	Point targetPageBitmapSize = new Point(mRawWallpaperSize);
	mWallpaperAsset.decodeBitmap(targetPageBitmapSize.x, targetPageBitmapSize.y,
	pageBitmap -> {
	// Check that the activity is still around since the decoding task started.
	if (getActivity() == null) {
	return;
	}

	// Some of these may be null depending on if the Fragment is paused, stopped,
	// or destroyed.
	if (mLoadingProgressBar != null) {
	mLoadingProgressBar.hide();
	}
	// The page bitmap may be null if there was a decoding error, so show an
	// error dialog.
	if (pageBitmap == null) {
	showLoadWallpaperErrorDialog();
	return;
	}
	if (mFullResImageView != null) {
	// Set page bitmap.
	mFullResImageView.setImage(ImageSource.bitmap(pageBitmap));

	setDefaultWallpaperZoomAndScroll();
	crossFadeInMosaicView();
	}
	getActivity().invalidateOptionsMenu();

	if (mWallpaperInfoView != null && mWallpaper != null) {
	mWallpaperInfoView.populateWallpaperInfo(mWallpaper, mActionLabel,
	mExploreIntent, this::onExploreClicked);
	}
	});
	}

	/**
	* Makes the MosaicView visible with an alpha fade-in animation while fading out the loading
	* indicator.
	*/
	private void crossFadeInMosaicView() {
	long shortAnimationDuration = getResources().getInteger(
	android.R.integer.config_shortAnimTime);

	mFullResImageView.setAlpha(0f);
	mFullResImageView.animate()
	.alpha(1f)
	.setDuration(shortAnimationDuration)
	.setListener(new AnimatorListenerAdapter() {
	@Override
	public void onAnimationEnd(Animator animation) {
	// Clear the thumbnail bitmap reference to save memory since it's no longer
	// visible.
	if (mLowResImageView != null) {
	mLowResImageView.setImageBitmap(null);
	}
	}
	});

	mLoadingProgressBar.animate()
	.alpha(0f)
	.setDuration(shortAnimationDuration)
	.setListener(new AnimatorListenerAdapter() {
	@Override
	public void onAnimationEnd(Animator animation) {
	if (mLoadingProgressBar != null) {
	mLoadingProgressBar.hide();
	}
	}
	});
	}

	/**
	* Sets the default wallpaper zoom and scroll position based on a "crop surface" (with extra
	* width to account for parallax) superimposed on the screen. Shows as much of the wallpaper as
	* possible on the crop surface and align screen to crop surface such that the default preview
	* matches what would be seen by the user in the left-most home screen.
	*
	* <p>This method is called once in the Fragment lifecycle after the wallpaper asset has loaded
	* and rendered to the layout.
	*/
	private void setDefaultWallpaperZoomAndScroll() {
	// Determine minimum zoom to fit maximum visible area of wallpaper on crop surface.
	int cropWidth = mWorkspaceSurface.getMeasuredWidth();
	int cropHeight = mWorkspaceSurface.getMeasuredHeight();
	Point crop = new Point(cropWidth, cropHeight);
	Rect visibleRawWallpaperRect =
	WallpaperCropUtils.calculateVisibleRect(mRawWallpaperSize, crop);

	final PointF centerPosition = WallpaperCropUtils.calculateDefaultCenter(requireContext(),
	mRawWallpaperSize, visibleRawWallpaperRect);

	Point visibleRawWallpaperSize = new Point(visibleRawWallpaperRect.width(),
	visibleRawWallpaperRect.height());

	final float defaultWallpaperZoom = WallpaperCropUtils.calculateMinZoom(
	visibleRawWallpaperSize, crop);
	final float minWallpaperZoom = defaultWallpaperZoom;


	// Set min wallpaper zoom and max zoom on MosaicView widget.
	mFullResImageView.setMaxScale(Math.max(DEFAULT_WALLPAPER_MAX_ZOOM, defaultWallpaperZoom));
	mFullResImageView.setMinScale(minWallpaperZoom);

	// Set center to composite positioning between scaled wallpaper and screen.
	mFullResImageView.setScaleAndCenter(minWallpaperZoom, centerPosition);
	}

	private Rect calculateCropRect() {
	float wallpaperZoom = mFullResImageView.getScale();
	Context context = requireContext().getApplicationContext();

	Rect visibleFileRect = new Rect();
	mFullResImageView.visibleFileRect(visibleFileRect);

	int cropWidth = mWorkspaceSurface.getMeasuredWidth();
	int cropHeight = mWorkspaceSurface.getMeasuredHeight();
	Point hostViewSize = new Point(cropWidth, cropHeight);
	Rect cropRect = WallpaperCropUtils.calculateCropRect(context, hostViewSize,
	hostViewSize, mRawWallpaperSize, visibleFileRect, wallpaperZoom);
	WallpaperCropUtils.adjustCropRect(context, cropRect, false /* zoomIn */);
	return cropRect;
	}

	@Override
	protected void setCurrentWallpaper(@Destination int destination) {
	mWallpaperSetter.setCurrentWallpaper(getActivity(), mWallpaper, mWallpaperAsset,
	destination, mFullResImageView.getScale(), calculateCropRect(),
	new SetWallpaperCallback() {
	@Override
	public void onSuccess(WallpaperInfo wallpaperInfo) {
	finishActivity(/* success= */ true);
	}

	@Override
	public void onError(@Nullable Throwable throwable) {
	showSetWallpaperErrorDialog(destination);
	}
	});
	}

	private void renderWorkspaceSurface() {
	mWorkspaceSurface.setZOrderMediaOverlay(true);
	mWorkspaceSurface.getHolder().addCallback(mWorkspaceSurfaceCallback);
	}

	private void renderImageWallpaper() {
	mWallpaperSurface.getHolder().addCallback(mWallpaperSurfaceCallback);
	}

	private class WallpaperSurfaceCallback implements SurfaceHolder.Callback {

	private Surface mLastSurface;
	private SurfaceControlViewHost mHost;

	@Override
	public void surfaceCreated(SurfaceHolder holder) {
	if (mLastSurface != holder.getSurface()) {
	mLastSurface = holder.getSurface();
	if (mFullResImageView != null) {
	mFullResImageView.recycle();
	}
	View wallpaperPreviewContainer = LayoutInflater.from(getContext()).inflate(
	R.layout.fullscreen_wallpaper_preview, null);
	mFullResImageView = wallpaperPreviewContainer.findViewById(R.id.full_res_image);
	mLowResImageView = wallpaperPreviewContainer.findViewById(R.id.low_res_image);
	// Load a low-res placeholder image if there's a thumbnail available from the asset
	// that can be shown to the user more quickly than the full-sized image.
	if (mWallpaperAsset.hasLowResDataSource()) {
	Activity activity = requireActivity();
	mWallpaperAsset.loadLowResDrawable(activity, mLowResImageView, Color.BLACK,
	new WallpaperPreviewBitmapTransformation(
	activity.getApplicationContext(), isRtl()));
	}
	wallpaperPreviewContainer.measure(
	makeMeasureSpec(mWallpaperSurface.getWidth(), EXACTLY),
	makeMeasureSpec(mWallpaperSurface.getHeight(), EXACTLY));
	wallpaperPreviewContainer.layout(0, 0, mWallpaperSurface.getWidth(),
	mWallpaperSurface.getHeight());
	mTouchForwardingLayout.setTargetView(mFullResImageView);

	cleanUp();
	mHost = new SurfaceControlViewHost(getContext(),
	getContext().getDisplay(), mWallpaperSurface.getHostToken());
	mHost.setView(wallpaperPreviewContainer, wallpaperPreviewContainer.getWidth(),
	wallpaperPreviewContainer.getHeight());
	mWallpaperSurface.setChildSurfacePackage(mHost.getSurfacePackage());
	}
	}

	@Override
	public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { }

	@Override
	public void surfaceDestroyed(SurfaceHolder holder) { }

	public void cleanUp() {
	if (mHost != null) {
	mHost.release();
	mHost = null;
	}
	}
	};

	private void setEditingEnabled(boolean enabled) {
	mTouchForwardingLayout.setForwardingEnabled(enabled);
	}

	private void updateScreenPreview(boolean isHomeSelected) {
	mHome.setSelected(isHomeSelected);
	mLock.setSelected(!isHomeSelected);
	mWorkspaceSurface.setVisibility(isHomeSelected ? View.VISIBLE : View.INVISIBLE);
	mLockPreviewContainer.setVisibility(isHomeSelected ? View.INVISIBLE : View.VISIBLE);
	}
	}