src/com/android/wallpaper/picker/PreviewFragment.java - platform/packages/apps/WallpaperPicker2 - 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 com.android.wallpaper.picker;

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

 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.ActivityInfo;
 import android.content.res.Resources.NotFoundException;
 import android.content.res.TypedArray;
 import android.graphics.PorterDuff.Mode;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.GradientDrawable;
 import android.net.Uri;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.Window;
 import android.widget.Button;
 import android.widget.CheckBox;
 import android.widget.Toast;

 import androidx.annotation.CallSuper;
 import androidx.annotation.IdRes;
 import androidx.annotation.IntDef;
 import androidx.annotation.LayoutRes;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.appcompat.widget.Toolbar;
 import androidx.core.view.ViewCompat;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;

 import com.android.wallpaper.R;
 import com.android.wallpaper.compat.BuildCompat;
 import com.android.wallpaper.model.LiveWallpaperInfo;
 import com.android.wallpaper.model.WallpaperInfo;
 import com.android.wallpaper.module.ExploreIntentChecker;
 import com.android.wallpaper.module.Injector;
 import com.android.wallpaper.module.InjectorProvider;
 import com.android.wallpaper.module.UserEventLogger;
 import com.android.wallpaper.module.WallpaperPersister.Destination;
 import com.android.wallpaper.module.WallpaperPreferences;
 import com.android.wallpaper.module.WallpaperSetter;

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

 import java.util.Date;
 import java.util.List;

 /**
  * Base Fragment to display the UI for previewing an individual wallpaper
  */
 public abstract class PreviewFragment extends Fragment implements
         SetWallpaperDialogFragment.Listener, SetWallpaperErrorDialogFragment.Listener,
         LoadWallpaperErrorDialogFragment.Listener {

     /**
      * User can view wallpaper and attributions in full screen, but "Set wallpaper" button is hidden.
      */
     static final int MODE_VIEW_ONLY = 0;

     /**
      * User can view wallpaper and attributions in full screen and click "Set wallpaper" to set the
      * wallpaper with pan and crop position to the device.
      */
     static final int MODE_CROP_AND_SET_WALLPAPER = 1;

     /**
      * Possible preview modes for the fragment.
      */
     @IntDef({
             MODE_VIEW_ONLY,
             MODE_CROP_AND_SET_WALLPAPER})
     public @interface PreviewMode {
     }

     public static final String ARG_WALLPAPER = "wallpaper";
     public static final String ARG_PREVIEW_MODE = "preview_mode";
     public static final String ARG_TESTING_MODE_ENABLED = "testing_mode_enabled";
     private static final String TAG_LOAD_WALLPAPER_ERROR_DIALOG_FRAGMENT =
             "load_wallpaper_error_dialog";
     private static final String TAG_SET_WALLPAPER_ERROR_DIALOG_FRAGMENT =
             "set_wallpaper_error_dialog";
     private static final int UNUSED_REQUEST_CODE = 1;
     private static final String TAG = "PreviewFragment";
     static final String KEY_BOTTOM_SHEET_STATE = "key_bottom_sheet_state";

     @PreviewMode
     protected int mPreviewMode;

     /**
      * When true, enables a test mode of operation -- in which certain UI features are disabled to
      * allow for UI tests to run correctly. Works around issue in ProgressDialog currently where the
      * dialog constantly keeps the UI thread alive and blocks a test forever.
      */
     protected boolean mTestingModeEnabled;

     protected WallpaperInfo mWallpaper;
     protected WallpaperSetter mWallpaperSetter;
     protected UserEventLogger mUserEventLogger;
     protected ViewGroup mBottomSheet;

     protected CheckBox mPreview;

     @SuppressWarnings("RestrictTo")
     @State
     protected int mBottomSheetInitialState;

     protected Intent mExploreIntent;

     /**
      * Staged error dialog fragments that were unable to be shown when the hosting activity didn't
      * allow committing fragment transactions.
      */
     private SetWallpaperErrorDialogFragment mStagedSetWallpaperErrorDialogFragment;
     private LoadWallpaperErrorDialogFragment mStagedLoadWallpaperErrorDialogFragment;

     protected static int getAttrColor(Context context, int attr) {
         TypedArray ta = context.obtainStyledAttributes(new int[]{attr});
         int colorAccent = ta.getColor(0, 0);
         ta.recycle();
         return colorAccent;
     }

     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         Activity activity = getActivity();
         Context appContext = getContext().getApplicationContext();
         Injector injector = InjectorProvider.getInjector();

         mUserEventLogger = injector.getUserEventLogger(appContext);
         mWallpaper = getArguments().getParcelable(ARG_WALLPAPER);

         //noinspection ResourceType
         mPreviewMode = getArguments().getInt(ARG_PREVIEW_MODE);
         mTestingModeEnabled = getArguments().getBoolean(ARG_TESTING_MODE_ENABLED);
         mWallpaperSetter = new WallpaperSetter(injector.getWallpaperPersister(appContext),
                 injector.getPreferences(appContext), mUserEventLogger, mTestingModeEnabled);

         setHasOptionsMenu(true);

         // Allow the layout to draw fullscreen even behind the status bar, so we can set as the status
         // bar color a color that has a custom translucency in the theme.
         Window window = activity.getWindow();
         window.getDecorView().setSystemUiVisibility(
                 View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                         | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                         | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);

         List<String> attributions = mWallpaper.getAttributions(activity);
         if (attributions.size() > 0 && attributions.get(0) != null) {
             activity.setTitle(attributions.get(0));
         }
     }

     @LayoutRes
     protected abstract int getLayoutResId();

     @Override
     @CallSuper
     public View onCreateView(LayoutInflater inflater, ViewGroup container,
                              Bundle savedInstanceState) {
         View view = inflater.inflate(getLayoutResId(), container, false);

         // Set toolbar as the action bar.
         Toolbar toolbar = view.findViewById(R.id.toolbar);
         AppCompatActivity activity = (AppCompatActivity) requireActivity();
         activity.setSupportActionBar(toolbar);
         activity.getSupportActionBar().setDisplayHomeAsUpEnabled(true);
         activity.getSupportActionBar().setDisplayShowTitleEnabled(false);

         // Use updated fancy arrow icon for O+.
         if (BuildCompat.isAtLeastO()) {
             Drawable navigationIcon = getResources().getDrawable(
                     R.drawable.material_ic_arrow_back_black_24);

             // This Drawable's state is shared across the app, so make a copy of it before applying a
             // color tint as not to affect other clients elsewhere in the app.
             navigationIcon = navigationIcon.getConstantState().newDrawable().mutate();
             navigationIcon.setColorFilter(
                     getResources().getColor(R.color.material_white_100), Mode.SRC_IN);
             navigationIcon.setAutoMirrored(true);
             toolbar.setNavigationIcon(navigationIcon);
         }

         ViewCompat.setPaddingRelative(toolbar,
         /* start */ getResources().getDimensionPixelSize(
                         R.dimen.preview_toolbar_up_button_start_padding),
         /* top */ 0,
         /* end */ getResources().getDimensionPixelSize(
                         R.dimen.preview_toolbar_set_wallpaper_button_end_padding),
         /* bottom */ 0);

         mBottomSheet = view.findViewById(getBottomSheetResId());
         setUpBottomSheetView(mBottomSheet);

         // Workaround as we don't have access to bottomDialogCornerRadius, mBottomSheet radii are
         // set to dialogCornerRadius by default.
         GradientDrawable bottomSheetBackground = (GradientDrawable) mBottomSheet.getBackground();
         float[] radii = bottomSheetBackground.getCornerRadii();
         for (int i = 0; i < radii.length; i++) {
             radii[i]*=2f;
         }
         bottomSheetBackground = ((GradientDrawable)bottomSheetBackground.mutate());
         bottomSheetBackground.setCornerRadii(radii);
         mBottomSheet.setBackground(bottomSheetBackground);

         mBottomSheetInitialState = (savedInstanceState == null) ? STATE_EXPANDED
                 : savedInstanceState.getInt(KEY_BOTTOM_SHEET_STATE, STATE_EXPANDED);
         setUpBottomSheetListeners();

         return view;
     }

     protected abstract void setUpBottomSheetView(ViewGroup bottomSheet);

     @IdRes
     protected abstract int getBottomSheetResId();

     protected int getDeviceDefaultTheme() {
         return android.R.style.Theme_DeviceDefault;
     }

     @Override
     public void onResume() {
         super.onResume();

         WallpaperPreferences preferences =
                 InjectorProvider.getInjector().getPreferences(getActivity());
         preferences.setLastAppActiveTimestamp(new Date().getTime());

         // Show the staged 'load wallpaper' or 'set wallpaper' error dialog fragments if there is
         // one that was unable to be shown earlier when this fragment's hosting activity didn't
         // allow committing fragment transactions.
         if (mStagedLoadWallpaperErrorDialogFragment != null) {
             mStagedLoadWallpaperErrorDialogFragment.show(
                     requireFragmentManager(), TAG_LOAD_WALLPAPER_ERROR_DIALOG_FRAGMENT);
             mStagedLoadWallpaperErrorDialogFragment = null;
         }
         if (mStagedSetWallpaperErrorDialogFragment != null) {
             mStagedSetWallpaperErrorDialogFragment.show(
                     requireFragmentManager(), TAG_SET_WALLPAPER_ERROR_DIALOG_FRAGMENT);
             mStagedSetWallpaperErrorDialogFragment = null;
         }
     }

     @Override
     public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
         super.onCreateOptionsMenu(menu, inflater);
         inflater.inflate(R.menu.preview_menu, menu);
     }

     @Override
     public void onPrepareOptionsMenu(Menu menu) {
         super.onPrepareOptionsMenu(menu);
         setupPreviewMenu(menu);
     }

     @Override
     public boolean onOptionsItemSelected(MenuItem item) {
         int id = item.getItemId();
         if (id == android.R.id.home) {
             // The Preview screen has multiple entry points. It could be opened from either
             // the IndividualPreviewActivity, the "My photos" selection (by way of
             // TopLevelPickerActivity), or from a system "crop and set wallpaper" intent.
             // Therefore, handle the Up button as a global Back.
             requireActivity().onBackPressed();
             return true;
         }

         return false;
     }

     private void setupPreviewMenu(Menu menu) {
         mPreview = (CheckBox) menu.findItem(R.id.preview).getActionView();
         mPreview.setChecked(mBottomSheetInitialState == STATE_COLLAPSED);
         mPreview.setOnClickListener(this::setPreviewBehavior);
     }

     protected void setPreviewChecked(boolean checked) {
         if (mPreview != null) {
             mPreview.setChecked(checked);
             int resId = checked ? R.string.expand_attribution_panel
                     : R.string.collapse_attribution_panel;
             mPreview.setContentDescription(getResources().getString(resId));
         }
     }

     private void setPreviewBehavior(View v) {
         CheckBox checkbox = (CheckBox) v;
         BottomSheetBehavior<?> behavior = BottomSheetBehavior.from(mBottomSheet);

         if (checkbox.isChecked()) {
             behavior.setState(STATE_COLLAPSED);
         } else {
             behavior.setState(STATE_EXPANDED);
         }
     }

     protected void setUpSetWallpaperButton(Button setWallpaperButton) {
         if (mPreviewMode == MODE_VIEW_ONLY) {
             setWallpaperButton.setVisibility(View.GONE);
         } else {
             setWallpaperButton.setVisibility(View.VISIBLE);
             setWallpaperButton.setOnClickListener(this::onSetWallpaperClicked);
         }
     }

     protected void setUpExploreButton(Button exploreButton) {
         exploreButton.setVisibility(View.GONE);
         if (mExploreIntent == null) {
             return;
         }
         Context context = requireContext();
         exploreButton.setVisibility(View.VISIBLE);
         exploreButton.setText(context.getString(
                 mWallpaper.getActionLabelRes(context)));

         exploreButton.setOnClickListener(view -> {
             mUserEventLogger.logActionClicked(mWallpaper.getCollectionId(context),
                     mWallpaper.getActionLabelRes(context));

             startActivity(mExploreIntent);
         });
     }

     protected void setUpExploreIntent(@Nullable Runnable callback) {
         Context context = getContext();
         if (context == null) {
             return;
         }
         ExploreIntentChecker intentChecker =
                 InjectorProvider.getInjector().getExploreIntentChecker(context);
         String actionUrl = mWallpaper.getActionUrl(context);
         if (actionUrl != null && !actionUrl.isEmpty()) {
             Uri exploreUri = Uri.parse(mWallpaper.getActionUrl(context));

             intentChecker.fetchValidActionViewIntent(exploreUri, exploreIntent -> {
                 if (getActivity() == null) {
                     return;
                 }

                 mExploreIntent = exploreIntent;
                 if (callback != null) {
                     callback.run();
                 }
             });
         } else {
             if (callback != null) {
                 callback.run();
             }
         }
     }

     @Override
     public void onSet(int destination) {
         setCurrentWallpaper(destination);
     }

     @Override
     public void onClickTryAgain(@Destination int wallpaperDestination) {
         setCurrentWallpaper(wallpaperDestination);
     }

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

     @Override
     public void onDestroy() {
         super.onDestroy();
         mWallpaperSetter.cleanUp();
     }

     @Override
     public void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);

         final BottomSheetBehavior bottomSheetBehavior = BottomSheetBehavior.from(mBottomSheet);
         outState.putInt(KEY_BOTTOM_SHEET_STATE, bottomSheetBehavior.getState());
     }

     private void onSetWallpaperClicked(View button) {
         mWallpaperSetter.requestDestination(getContext(), getFragmentManager(), this,
                 mWallpaper instanceof LiveWallpaperInfo);
     }

     private void setUpBottomSheetListeners() {
         final BottomSheetBehavior bottomSheetBehavior = BottomSheetBehavior.from(mBottomSheet);

         bottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
             @Override
             public void onStateChanged(View bottomSheet, int newState) {
                 // Don't respond to lingering state change events occurring after the fragment has
                 // already been detached from the activity. Else, IllegalStateException may occur
                 // when trying to fetch resources.
                 if (getActivity() == null) {
                     return;
                 }
                 switch (newState) {
                     case STATE_COLLAPSED:
                         setPreviewChecked(true /* checked */);
                         break;
                     case STATE_EXPANDED:
                         setPreviewChecked(false /* checked */);
                         break;
                     default:
                         Log.v(TAG, "Ignoring BottomSheet state: " + newState);
                 }
             }

             @Override
             public void onSlide(View bottomSheet, float slideOffset) {
                 float alpha;
                 if (slideOffset >= 0) {
                     alpha = slideOffset;
                 } else {
                     alpha = 1f - slideOffset;
                 }
                 setBottomSheetContentAlpha(alpha);
             }
         });
     }

     protected void setBottomSheetContentAlpha(float alpha) {

     }

     /**
      * Sets current wallpaper to the device based on current zoom and scroll state.
      *
      * @param destination The wallpaper destination i.e. home vs. lockscreen vs. both.
      */
     protected abstract void setCurrentWallpaper(@Destination int destination);

     protected void finishActivityWithResultOk() {
         Activity activity = requireActivity();
         try {
             Toast.makeText(activity,
                     R.string.wallpaper_set_successfully_message, Toast.LENGTH_SHORT).show();
         } catch (NotFoundException e) {
             Log.e(TAG, "Could not show toast " + e);
         }
         activity.overridePendingTransition(R.anim.fade_in, R.anim.fade_out);
         activity.setResult(Activity.RESULT_OK);
         activity.finish();
     }

     protected void showSetWallpaperErrorDialog(@Destination int wallpaperDestination) {
         SetWallpaperErrorDialogFragment newFragment = SetWallpaperErrorDialogFragment.newInstance(
                 R.string.set_wallpaper_error_message, wallpaperDestination);
         newFragment.setTargetFragment(this, UNUSED_REQUEST_CODE);

         // Show 'set wallpaper' error dialog now if it's safe to commit fragment transactions,
         // otherwise stage it for later when the hosting activity is in a state to commit fragment
         // transactions.
         BasePreviewActivity activity = (BasePreviewActivity) requireActivity();
         if (activity.isSafeToCommitFragmentTransaction()) {
             newFragment.show(requireFragmentManager(), TAG_SET_WALLPAPER_ERROR_DIALOG_FRAGMENT);
         } else {
             mStagedSetWallpaperErrorDialogFragment = newFragment;
         }
     }

     /**
      * Shows 'load wallpaper' error dialog now or stage it to be shown when the hosting activity is
      * in a state that allows committing fragment transactions.
      */
     protected void showLoadWallpaperErrorDialog() {
         LoadWallpaperErrorDialogFragment dialogFragment =
                 LoadWallpaperErrorDialogFragment.newInstance();
         dialogFragment.setTargetFragment(this, UNUSED_REQUEST_CODE);

         // Show 'load wallpaper' error dialog now or stage it to be shown when the hosting
         // activity is in a state that allows committing fragment transactions.
         BasePreviewActivity activity = (BasePreviewActivity) getActivity();
         if (activity != null && activity.isSafeToCommitFragmentTransaction()) {
             dialogFragment.show(requireFragmentManager(), TAG_LOAD_WALLPAPER_ERROR_DIALOG_FRAGMENT);
         } else {
             mStagedLoadWallpaperErrorDialogFragment = dialogFragment;
         }
     }

     @IntDef({
             ActivityInfo.SCREEN_ORIENTATION_PORTRAIT,
             ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE,
             ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT,
             ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE})
     private @interface ActivityInfoScreenOrientation {
     }

     /**
      * Returns whether layout direction is RTL (or false for LTR). Since native RTL layout support
      * was added in API 17, returns false for versions lower than 17.
      */
     protected boolean isRtl() {
         return getResources().getConfiguration().getLayoutDirection()
                     == View.LAYOUT_DIRECTION_RTL;
     }
 }
	/*
	* 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 com.android.wallpaper.picker;

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

	import android.app.Activity;
	import android.content.Context;
	import android.content.Intent;
	import android.content.pm.ActivityInfo;
	import android.content.res.Resources.NotFoundException;
	import android.content.res.TypedArray;
	import android.graphics.PorterDuff.Mode;
	import android.graphics.drawable.Drawable;
	import android.graphics.drawable.GradientDrawable;
	import android.net.Uri;
	import android.os.Bundle;
	import android.util.Log;
	import android.view.LayoutInflater;
	import android.view.Menu;
	import android.view.MenuInflater;
	import android.view.MenuItem;
	import android.view.View;
	import android.view.ViewGroup;
	import android.view.Window;
	import android.widget.Button;
	import android.widget.CheckBox;
	import android.widget.Toast;

	import androidx.annotation.CallSuper;
	import androidx.annotation.IdRes;
	import androidx.annotation.IntDef;
	import androidx.annotation.LayoutRes;
	import androidx.annotation.Nullable;
	import androidx.appcompat.app.AppCompatActivity;
	import androidx.appcompat.widget.Toolbar;
	import androidx.core.view.ViewCompat;
	import androidx.fragment.app.Fragment;
	import androidx.fragment.app.FragmentActivity;

	import com.android.wallpaper.R;
	import com.android.wallpaper.compat.BuildCompat;
	import com.android.wallpaper.model.LiveWallpaperInfo;
	import com.android.wallpaper.model.WallpaperInfo;
	import com.android.wallpaper.module.ExploreIntentChecker;
	import com.android.wallpaper.module.Injector;
	import com.android.wallpaper.module.InjectorProvider;
	import com.android.wallpaper.module.UserEventLogger;
	import com.android.wallpaper.module.WallpaperPersister.Destination;
	import com.android.wallpaper.module.WallpaperPreferences;
	import com.android.wallpaper.module.WallpaperSetter;

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

	import java.util.Date;
	import java.util.List;

	/**
	* Base Fragment to display the UI for previewing an individual wallpaper
	*/
	public abstract class PreviewFragment extends Fragment implements
	SetWallpaperDialogFragment.Listener, SetWallpaperErrorDialogFragment.Listener,
	LoadWallpaperErrorDialogFragment.Listener {

	/**
	* User can view wallpaper and attributions in full screen, but "Set wallpaper" button is hidden.
	*/
	static final int MODE_VIEW_ONLY = 0;

	/**
	* User can view wallpaper and attributions in full screen and click "Set wallpaper" to set the
	* wallpaper with pan and crop position to the device.
	*/
	static final int MODE_CROP_AND_SET_WALLPAPER = 1;

	/**
	* Possible preview modes for the fragment.
	*/
	@IntDef({
	MODE_VIEW_ONLY,
	MODE_CROP_AND_SET_WALLPAPER})
	public @interface PreviewMode {
	}

	public static final String ARG_WALLPAPER = "wallpaper";
	public static final String ARG_PREVIEW_MODE = "preview_mode";
	public static final String ARG_TESTING_MODE_ENABLED = "testing_mode_enabled";
	private static final String TAG_LOAD_WALLPAPER_ERROR_DIALOG_FRAGMENT =
	"load_wallpaper_error_dialog";
	private static final String TAG_SET_WALLPAPER_ERROR_DIALOG_FRAGMENT =
	"set_wallpaper_error_dialog";
	private static final int UNUSED_REQUEST_CODE = 1;
	private static final String TAG = "PreviewFragment";
	static final String KEY_BOTTOM_SHEET_STATE = "key_bottom_sheet_state";

	@PreviewMode
	protected int mPreviewMode;

	/**
	* When true, enables a test mode of operation -- in which certain UI features are disabled to
	* allow for UI tests to run correctly. Works around issue in ProgressDialog currently where the
	* dialog constantly keeps the UI thread alive and blocks a test forever.
	*/
	protected boolean mTestingModeEnabled;

	protected WallpaperInfo mWallpaper;
	protected WallpaperSetter mWallpaperSetter;
	protected UserEventLogger mUserEventLogger;
	protected ViewGroup mBottomSheet;

	protected CheckBox mPreview;

	@SuppressWarnings("RestrictTo")
	@State
	protected int mBottomSheetInitialState;

	protected Intent mExploreIntent;

	/**
	* Staged error dialog fragments that were unable to be shown when the hosting activity didn't
	* allow committing fragment transactions.
	*/
	private SetWallpaperErrorDialogFragment mStagedSetWallpaperErrorDialogFragment;
	private LoadWallpaperErrorDialogFragment mStagedLoadWallpaperErrorDialogFragment;

	protected static int getAttrColor(Context context, int attr) {
	TypedArray ta = context.obtainStyledAttributes(new int[]{attr});
	int colorAccent = ta.getColor(0, 0);
	ta.recycle();
	return colorAccent;
	}

	@Override
	public void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);

	Activity activity = getActivity();
	Context appContext = getContext().getApplicationContext();
	Injector injector = InjectorProvider.getInjector();

	mUserEventLogger = injector.getUserEventLogger(appContext);
	mWallpaper = getArguments().getParcelable(ARG_WALLPAPER);

	//noinspection ResourceType
	mPreviewMode = getArguments().getInt(ARG_PREVIEW_MODE);
	mTestingModeEnabled = getArguments().getBoolean(ARG_TESTING_MODE_ENABLED);
	mWallpaperSetter = new WallpaperSetter(injector.getWallpaperPersister(appContext),
	injector.getPreferences(appContext), mUserEventLogger, mTestingModeEnabled);

	setHasOptionsMenu(true);

	// Allow the layout to draw fullscreen even behind the status bar, so we can set as the status
	// bar color a color that has a custom translucency in the theme.
	Window window = activity.getWindow();
	window.getDecorView().setSystemUiVisibility(
	View.SYSTEM_UI_FLAG_LAYOUT_STABLE
	\| View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
	\| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION);

	List<String> attributions = mWallpaper.getAttributions(activity);
	if (attributions.size() > 0 && attributions.get(0) != null) {
	activity.setTitle(attributions.get(0));
	}
	}

	@LayoutRes
	protected abstract int getLayoutResId();

	@Override
	@CallSuper
	public View onCreateView(LayoutInflater inflater, ViewGroup container,
	Bundle savedInstanceState) {
	View view = inflater.inflate(getLayoutResId(), container, false);

	// Set toolbar as the action bar.
	Toolbar toolbar = view.findViewById(R.id.toolbar);
	AppCompatActivity activity = (AppCompatActivity) requireActivity();
	activity.setSupportActionBar(toolbar);
	activity.getSupportActionBar().setDisplayHomeAsUpEnabled(true);
	activity.getSupportActionBar().setDisplayShowTitleEnabled(false);

	// Use updated fancy arrow icon for O+.
	if (BuildCompat.isAtLeastO()) {
	Drawable navigationIcon = getResources().getDrawable(
	R.drawable.material_ic_arrow_back_black_24);

	// This Drawable's state is shared across the app, so make a copy of it before applying a
	// color tint as not to affect other clients elsewhere in the app.
	navigationIcon = navigationIcon.getConstantState().newDrawable().mutate();
	navigationIcon.setColorFilter(
	getResources().getColor(R.color.material_white_100), Mode.SRC_IN);
	navigationIcon.setAutoMirrored(true);
	toolbar.setNavigationIcon(navigationIcon);
	}

	ViewCompat.setPaddingRelative(toolbar,
	/* start */ getResources().getDimensionPixelSize(
	R.dimen.preview_toolbar_up_button_start_padding),
	/* top */ 0,
	/* end */ getResources().getDimensionPixelSize(
	R.dimen.preview_toolbar_set_wallpaper_button_end_padding),
	/* bottom */ 0);

	mBottomSheet = view.findViewById(getBottomSheetResId());
	setUpBottomSheetView(mBottomSheet);

	// Workaround as we don't have access to bottomDialogCornerRadius, mBottomSheet radii are
	// set to dialogCornerRadius by default.
	GradientDrawable bottomSheetBackground = (GradientDrawable) mBottomSheet.getBackground();
	float[] radii = bottomSheetBackground.getCornerRadii();
	for (int i = 0; i < radii.length; i++) {
	radii[i]*=2f;
	}
	bottomSheetBackground = ((GradientDrawable)bottomSheetBackground.mutate());
	bottomSheetBackground.setCornerRadii(radii);
	mBottomSheet.setBackground(bottomSheetBackground);

	mBottomSheetInitialState = (savedInstanceState == null) ? STATE_EXPANDED
	: savedInstanceState.getInt(KEY_BOTTOM_SHEET_STATE, STATE_EXPANDED);
	setUpBottomSheetListeners();

	return view;
	}

	protected abstract void setUpBottomSheetView(ViewGroup bottomSheet);

	@IdRes
	protected abstract int getBottomSheetResId();

	protected int getDeviceDefaultTheme() {
	return android.R.style.Theme_DeviceDefault;
	}

	@Override
	public void onResume() {
	super.onResume();

	WallpaperPreferences preferences =
	InjectorProvider.getInjector().getPreferences(getActivity());
	preferences.setLastAppActiveTimestamp(new Date().getTime());

	// Show the staged 'load wallpaper' or 'set wallpaper' error dialog fragments if there is
	// one that was unable to be shown earlier when this fragment's hosting activity didn't
	// allow committing fragment transactions.
	if (mStagedLoadWallpaperErrorDialogFragment != null) {
	mStagedLoadWallpaperErrorDialogFragment.show(
	requireFragmentManager(), TAG_LOAD_WALLPAPER_ERROR_DIALOG_FRAGMENT);
	mStagedLoadWallpaperErrorDialogFragment = null;
	}
	if (mStagedSetWallpaperErrorDialogFragment != null) {
	mStagedSetWallpaperErrorDialogFragment.show(
	requireFragmentManager(), TAG_SET_WALLPAPER_ERROR_DIALOG_FRAGMENT);
	mStagedSetWallpaperErrorDialogFragment = null;
	}
	}

	@Override
	public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
	super.onCreateOptionsMenu(menu, inflater);
	inflater.inflate(R.menu.preview_menu, menu);
	}

	@Override
	public void onPrepareOptionsMenu(Menu menu) {
	super.onPrepareOptionsMenu(menu);
	setupPreviewMenu(menu);
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
	int id = item.getItemId();
	if (id == android.R.id.home) {
	// The Preview screen has multiple entry points. It could be opened from either
	// the IndividualPreviewActivity, the "My photos" selection (by way of
	// TopLevelPickerActivity), or from a system "crop and set wallpaper" intent.
	// Therefore, handle the Up button as a global Back.
	requireActivity().onBackPressed();
	return true;
	}

	return false;
	}

	private void setupPreviewMenu(Menu menu) {
	mPreview = (CheckBox) menu.findItem(R.id.preview).getActionView();
	mPreview.setChecked(mBottomSheetInitialState == STATE_COLLAPSED);
	mPreview.setOnClickListener(this::setPreviewBehavior);
	}

	protected void setPreviewChecked(boolean checked) {
	if (mPreview != null) {
	mPreview.setChecked(checked);
	int resId = checked ? R.string.expand_attribution_panel
	: R.string.collapse_attribution_panel;
	mPreview.setContentDescription(getResources().getString(resId));
	}
	}

	private void setPreviewBehavior(View v) {
	CheckBox checkbox = (CheckBox) v;
	BottomSheetBehavior<?> behavior = BottomSheetBehavior.from(mBottomSheet);

	if (checkbox.isChecked()) {
	behavior.setState(STATE_COLLAPSED);
	} else {
	behavior.setState(STATE_EXPANDED);
	}
	}

	protected void setUpSetWallpaperButton(Button setWallpaperButton) {
	if (mPreviewMode == MODE_VIEW_ONLY) {
	setWallpaperButton.setVisibility(View.GONE);
	} else {
	setWallpaperButton.setVisibility(View.VISIBLE);
	setWallpaperButton.setOnClickListener(this::onSetWallpaperClicked);
	}
	}

	protected void setUpExploreButton(Button exploreButton) {
	exploreButton.setVisibility(View.GONE);
	if (mExploreIntent == null) {
	return;
	}
	Context context = requireContext();
	exploreButton.setVisibility(View.VISIBLE);
	exploreButton.setText(context.getString(
	mWallpaper.getActionLabelRes(context)));

	exploreButton.setOnClickListener(view -> {
	mUserEventLogger.logActionClicked(mWallpaper.getCollectionId(context),
	mWallpaper.getActionLabelRes(context));

	startActivity(mExploreIntent);
	});
	}

	protected void setUpExploreIntent(@Nullable Runnable callback) {
	Context context = getContext();
	if (context == null) {
	return;
	}
	ExploreIntentChecker intentChecker =
	InjectorProvider.getInjector().getExploreIntentChecker(context);
	String actionUrl = mWallpaper.getActionUrl(context);
	if (actionUrl != null && !actionUrl.isEmpty()) {
	Uri exploreUri = Uri.parse(mWallpaper.getActionUrl(context));

	intentChecker.fetchValidActionViewIntent(exploreUri, exploreIntent -> {
	if (getActivity() == null) {
	return;
	}

	mExploreIntent = exploreIntent;
	if (callback != null) {
	callback.run();
	}
	});
	} else {
	if (callback != null) {
	callback.run();
	}
	}
	}

	@Override
	public void onSet(int destination) {
	setCurrentWallpaper(destination);
	}

	@Override
	public void onClickTryAgain(@Destination int wallpaperDestination) {
	setCurrentWallpaper(wallpaperDestination);
	}

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

	@Override
	public void onDestroy() {
	super.onDestroy();
	mWallpaperSetter.cleanUp();
	}

	@Override
	public void onSaveInstanceState(Bundle outState) {
	super.onSaveInstanceState(outState);

	final BottomSheetBehavior bottomSheetBehavior = BottomSheetBehavior.from(mBottomSheet);
	outState.putInt(KEY_BOTTOM_SHEET_STATE, bottomSheetBehavior.getState());
	}

	private void onSetWallpaperClicked(View button) {
	mWallpaperSetter.requestDestination(getContext(), getFragmentManager(), this,
	mWallpaper instanceof LiveWallpaperInfo);
	}

	private void setUpBottomSheetListeners() {
	final BottomSheetBehavior bottomSheetBehavior = BottomSheetBehavior.from(mBottomSheet);

	bottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
	@Override
	public void onStateChanged(View bottomSheet, int newState) {
	// Don't respond to lingering state change events occurring after the fragment has
	// already been detached from the activity. Else, IllegalStateException may occur
	// when trying to fetch resources.
	if (getActivity() == null) {
	return;
	}
	switch (newState) {
	case STATE_COLLAPSED:
	setPreviewChecked(true /* checked */);
	break;
	case STATE_EXPANDED:
	setPreviewChecked(false /* checked */);
	break;
	default:
	Log.v(TAG, "Ignoring BottomSheet state: " + newState);
	}
	}

	@Override
	public void onSlide(View bottomSheet, float slideOffset) {
	float alpha;
	if (slideOffset >= 0) {
	alpha = slideOffset;
	} else {
	alpha = 1f - slideOffset;
	}
	setBottomSheetContentAlpha(alpha);
	}
	});
	}

	protected void setBottomSheetContentAlpha(float alpha) {

	}

	/**
	* Sets current wallpaper to the device based on current zoom and scroll state.
	*
	* @param destination The wallpaper destination i.e. home vs. lockscreen vs. both.
	*/
	protected abstract void setCurrentWallpaper(@Destination int destination);

	protected void finishActivityWithResultOk() {
	Activity activity = requireActivity();
	try {
	Toast.makeText(activity,
	R.string.wallpaper_set_successfully_message, Toast.LENGTH_SHORT).show();
	} catch (NotFoundException e) {
	Log.e(TAG, "Could not show toast " + e);
	}
	activity.overridePendingTransition(R.anim.fade_in, R.anim.fade_out);
	activity.setResult(Activity.RESULT_OK);
	activity.finish();
	}

	protected void showSetWallpaperErrorDialog(@Destination int wallpaperDestination) {
	SetWallpaperErrorDialogFragment newFragment = SetWallpaperErrorDialogFragment.newInstance(
	R.string.set_wallpaper_error_message, wallpaperDestination);
	newFragment.setTargetFragment(this, UNUSED_REQUEST_CODE);

	// Show 'set wallpaper' error dialog now if it's safe to commit fragment transactions,
	// otherwise stage it for later when the hosting activity is in a state to commit fragment
	// transactions.
	BasePreviewActivity activity = (BasePreviewActivity) requireActivity();
	if (activity.isSafeToCommitFragmentTransaction()) {
	newFragment.show(requireFragmentManager(), TAG_SET_WALLPAPER_ERROR_DIALOG_FRAGMENT);
	} else {
	mStagedSetWallpaperErrorDialogFragment = newFragment;
	}
	}

	/**
	* Shows 'load wallpaper' error dialog now or stage it to be shown when the hosting activity is
	* in a state that allows committing fragment transactions.
	*/
	protected void showLoadWallpaperErrorDialog() {
	LoadWallpaperErrorDialogFragment dialogFragment =
	LoadWallpaperErrorDialogFragment.newInstance();
	dialogFragment.setTargetFragment(this, UNUSED_REQUEST_CODE);

	// Show 'load wallpaper' error dialog now or stage it to be shown when the hosting
	// activity is in a state that allows committing fragment transactions.
	BasePreviewActivity activity = (BasePreviewActivity) getActivity();
	if (activity != null && activity.isSafeToCommitFragmentTransaction()) {
	dialogFragment.show(requireFragmentManager(), TAG_LOAD_WALLPAPER_ERROR_DIALOG_FRAGMENT);
	} else {
	mStagedLoadWallpaperErrorDialogFragment = dialogFragment;
	}
	}

	@IntDef({
	ActivityInfo.SCREEN_ORIENTATION_PORTRAIT,
	ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE,
	ActivityInfo.SCREEN_ORIENTATION_REVERSE_PORTRAIT,
	ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE})
	private @interface ActivityInfoScreenOrientation {
	}

	/**
	* Returns whether layout direction is RTL (or false for LTR). Since native RTL layout support
	* was added in API 17, returns false for versions lower than 17.
	*/
	protected boolean isRtl() {
	return getResources().getConfiguration().getLayoutDirection()
	== View.LAYOUT_DIRECTION_RTL;
	}
	}