src/com/android/wallpaper/util/WallpaperCropUtils.java - LeafOS-Project/android_packages_apps_WallpaperPicker2 - Gitiles

 /*
  * 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.util;

 import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Point;
 import android.graphics.PointF;
 import android.graphics.Rect;
 import android.os.Build.VERSION;
 import android.os.Build.VERSION_CODES;
 import android.view.Display;
 import android.view.View;

 import com.android.systemui.shared.system.WallpaperManagerCompat;

 /**
  * Static utility methods for wallpaper cropping operations.
  */
 public final class WallpaperCropUtils {

     private static final float WALLPAPER_SCREENS_SPAN = 2f;
     private static final float ASPECT_RATIO_LANDSCAPE = 16 / 10f;
     private static final float ASPECT_RATIO_PORTRAIT = 10 / 16f;
     private static final float WALLPAPER_WIDTH_TO_SCREEN_RATIO_LANDSCAPE = 1.2f;
     private static final float WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT = 1.5f;

     // Suppress default constructor for noninstantiability.
     private WallpaperCropUtils() {
         throw new AssertionError();
     }

     /**
      * Calculates parallax travel (i.e., extra width) for a screen with the given resolution.
      */
     public static float wallpaperTravelToScreenWidthRatio(int width, int height) {
         float aspectRatio = width / (float) height;

         // At an aspect ratio of 16/10, the wallpaper parallax effect should span 1.2 * screen width
         // At an aspect ratio of 10/16, the wallpaper parallax effect should span 1.5 * screen width
         // We will use these two data points to extrapolate how much the wallpaper parallax effect
         // to span (i.e., travel) at any aspect ratio. We use the following two linear formulas,
         // where
         // the coefficient on x is the aspect ratio (width/height):
         //   (16/10)x + y = 1.2
         //   (10/16)x + y = 1.5
         // We solve for x and y and end up with a final formula:
         float x = (WALLPAPER_WIDTH_TO_SCREEN_RATIO_LANDSCAPE
                 - WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT)
                 / (ASPECT_RATIO_LANDSCAPE - ASPECT_RATIO_PORTRAIT);
         float y = WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT - x * ASPECT_RATIO_PORTRAIT;
         return x * aspectRatio + y;
     }

     /**
      * Calculates ideal crop surface size for a device such that there is room for parallax in both
      * landscape and portrait screen orientations.
      */
     public static Point getDefaultCropSurfaceSize(Resources resources, Display display) {
         Point minDims = new Point();
         Point maxDims = new Point();
         display.getCurrentSizeRange(minDims, maxDims);

         int maxDim = Math.max(maxDims.x, maxDims.y);
         int minDim = Math.max(minDims.x, minDims.y);

         if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN_MR1) {
             Point realSize = new Point();
             display.getRealSize(realSize);
             maxDim = Math.max(realSize.x, realSize.y);
             minDim = Math.min(realSize.x, realSize.y);
         }

         return calculateCropSurfaceSize(resources, maxDim, minDim, display.getWidth(),
                 display.getHeight());
     }

     /**
      * Calculates ideal crop surface size for a surface of dimensions maxDim x minDim such that
      * there is room for parallax in both* landscape and portrait screen orientations.
      */
     public static Point calculateCropSurfaceSize(Resources resources, int maxDim, int minDim,
             int width, int height) {
         final int defaultWidth, defaultHeight;
         if (resources.getConfiguration().smallestScreenWidthDp >= 720) {
             defaultWidth = (int) (maxDim * wallpaperTravelToScreenWidthRatio(maxDim, minDim));
         } else {
             defaultWidth = Math.max((int) (minDim * WALLPAPER_SCREENS_SPAN), maxDim);
         }
         defaultHeight = width < height ? maxDim : minDim;

         return new Point(defaultWidth, defaultHeight);
     }

     /**
      * Calculates the relative position between an outer and inner rectangle when the outer one is
      * center-cropped to the inner one.
      *
      * @param outer      Size of outer rectangle as a Point (x,y).
      * @param inner      Size of inner rectangle as a Point (x,y).
      * @param alignStart Whether the inner rectangle should be aligned to the start of the layout
      *                   with the outer one and ignore horizontal centering.
      * @param isRtl      Whether the layout direction is RTL (or false for LTR).
      * @return Position relative to the top left corner of the outer rectangle, where the size of
      * each rectangle is represented by Points, in coordinates (x,y) relative to the outer rectangle
      * where the top left corner is (0,0)
      * @throws IllegalArgumentException if inner rectangle is not contained within outer rectangle
      *                                  which would return a position with at least one negative
      *                                  coordinate.
      */
     public static Point calculateCenterPosition(Point outer, Point inner, boolean alignStart,
             boolean isRtl) {
         if (inner.x > outer.x || inner.y > outer.y) {
             throw new IllegalArgumentException("Inner rectangle " + inner + " should be contained"
                     + " completely within the outer rectangle " + outer + ".");
         }

         Point relativePosition = new Point();

         if (alignStart) {
             relativePosition.x = isRtl ? outer.x - inner.x : 0;
         } else {
             relativePosition.x = Math.round((outer.x - inner.x) / 2f);
         }
         relativePosition.y = Math.round((outer.y - inner.y) / 2f);

         return relativePosition;
     }

     /**
      * Calculates the minimum zoom such that the maximum surface area of the outer rectangle is
      * visible within the inner rectangle.
      *
      * @param outer Size of outer rectangle as a Point (x,y).
      * @param inner Size of inner rectangle as a Point (x,y).
      */
     public static float calculateMinZoom(Point outer, Point inner) {
         float minZoom;
         if (inner.x / (float) inner.y > outer.x / (float) outer.y) {
             minZoom = inner.x / (float) outer.x;
         } else {
             minZoom = inner.y / (float) outer.y;
         }
         return minZoom;
     }


     /**
      * Calculates the center position of a wallpaper of the given size, based on a "crop surface"
      * (with extra width to account for parallax) superimposed on the screen. Trying to show as
      * much of the wallpaper as possible on the crop surface and align screen to crop surface such
      * that the centered wallpaper matches what would be seen by the user in the left-most home
      * screen.
      *
      * @param wallpaperSize full size of the wallpaper
      * @param visibleWallpaperRect visible area available for the wallpaper
      * @return a point corresponding to the position of wallpaper that should be in the center
      *      of the screen.
      */
     public static PointF calculateDefaultCenter(Context context, Point wallpaperSize,
             Rect visibleWallpaperRect) {

         WallpaperCropUtils.adjustCurrentWallpaperCropRect(context, wallpaperSize,
                 visibleWallpaperRect);

         return new PointF(visibleWallpaperRect.centerX(),
                 visibleWallpaperRect.centerY());
     }

     /**
      * Calculates the rectangle to crop a wallpaper of the given size, and considering the given
      * scrollX and scrollY offsets
      * @param wallpaperZoom zoom applied to the raw wallpaper image
      * @param wallpaperSize full ("raw") wallpaper size
      * @param defaultCropSurfaceSize @see #getDefaultCropSurfaceSize(Resources, Display)
      * @param targetHostSize target size where the wallpaper will be rendered (eg, the display size)
      * @param scrollX x-axis offset the cropping area from the wallpaper's 0,0 position
      * @param scrollY y-axis offset the cropping area from the wallpaper's 0,0 position
      * @return a Rect representing the area of the wallpaper to crop.
      */
     public static Rect calculateCropRect(Context context, float wallpaperZoom, Point wallpaperSize,
             Point defaultCropSurfaceSize, Point targetHostSize, int scrollX, int scrollY) {
         // Calculate Rect of wallpaper in physical pixel terms (i.e., scaled to current zoom).
         int scaledWallpaperWidth = Math.round(wallpaperSize.x * wallpaperZoom);
         int scaledWallpaperHeight = Math.round(wallpaperSize.y * wallpaperZoom);
         Rect rect = new Rect();
         rect.set(0, 0, scaledWallpaperWidth, scaledWallpaperHeight);

         // Crop rect should start off as the visible screen and then include extra width and height
         // if available within wallpaper at the current zoom.
         Rect cropRect = new Rect(scrollX, scrollY, scrollX + targetHostSize.x,
                 scrollY + targetHostSize.y);

         int extraWidth = defaultCropSurfaceSize.x - targetHostSize.x;
         int extraHeightTopAndBottom = (int) ((defaultCropSurfaceSize.y - targetHostSize.y) / 2f);

         // Try to increase size of screenRect to include extra width depending on the layout
         // direction.
         if (isRtl(context)) {
             cropRect.left = Math.max(cropRect.left - extraWidth, rect.left);
         } else {
             cropRect.right = Math.min(cropRect.right + extraWidth, rect.right);
         }

         // Try to increase the size of the cropRect to to include extra height.
         int availableExtraHeightTop = cropRect.top - Math.max(
                 rect.top,
                 cropRect.top - extraHeightTopAndBottom);
         int availableExtraHeightBottom = Math.min(
                 rect.bottom,
                 cropRect.bottom + extraHeightTopAndBottom) - cropRect.bottom;

         int availableExtraHeightTopAndBottom =
                 Math.min(availableExtraHeightTop, availableExtraHeightBottom);
         cropRect.top -= availableExtraHeightTopAndBottom;
         cropRect.bottom += availableExtraHeightTopAndBottom;

         return cropRect;
     }

     /**
      * Calculates the center area of the outer rectangle which is visible in the inner rectangle
      * after applying the minimum zoom.
      *
      * @param outer the size of outer rectangle as a Point (x,y).
      * @param inner the size of inner rectangle as a Point (x,y).
      */
     public static Rect calculateVisibleRect(Point outer, Point inner) {
         PointF visibleRectCenter = new PointF(outer.x / 2f, outer.y / 2f);
         if (inner.x / (float) inner.y > outer.x / (float) outer.y) {
             float minZoom = inner.x / (float) outer.x;
             float visibleRectHeight = inner.y / minZoom;
             return new Rect(0, (int) (visibleRectCenter.y - visibleRectHeight / 2),
                     outer.x, (int) (visibleRectCenter.y + visibleRectHeight / 2));
         } else {
             float minZoom = inner.y / (float) outer.y;
             float visibleRectWidth = inner.x / minZoom;
             return new Rect((int) (visibleRectCenter.x - visibleRectWidth / 2),
                     0, (int) (visibleRectCenter.x + visibleRectWidth / 2), outer.y);
         }
     }

     public static void adjustCurrentWallpaperCropRect(Context context, Point assetDimensions,
             Rect cropRect) {
         adjustCropRect(context, cropRect, true /* zoomIn */);
     }

     /** Adjust the crop rect by zooming in with systemWallpaperMaxScale. */
     public static void adjustCropRect(Context context, Rect cropRect, boolean zoomIn) {
         float centerX = cropRect.centerX();
         float centerY = cropRect.centerY();
         float width = cropRect.width();
         float height = cropRect.height();
         float systemWallpaperMaxScale = getSystemWallpaperMaximumScale(context);
         float scale = zoomIn ? systemWallpaperMaxScale : 1.0f / systemWallpaperMaxScale;

         // Adjust the rect according to the system wallpaper's maximum scale.
         int left = (int) (centerX - (width / 2) / scale);
         int top = (int) (centerY - (height / 2) / scale);
         int right = (int) (centerX + (width / 2) / scale);
         int bottom = (int) (centerY + (height / 2) / scale);
         cropRect.set(left, top, right, bottom);
     }

     /** Adjust the given Point, representing a size by  systemWallpaperMaxScale. */
     public static void scaleSize(Context context, Point size) {
         float systemWallpaperMaxScale = getSystemWallpaperMaximumScale(context);
         size.set((int) (size.x * systemWallpaperMaxScale),
                 (int) (size.y * systemWallpaperMaxScale));
     }
     /**
      * Calculates {@link Rect} of the wallpaper which we want to crop to in physical pixel terms
      * (i.e., scaled to current zoom) when the wallpaper is laid on a fullscreen view.
      */
     public static Rect calculateCropRect(Context context, Display display, Point rawWallpaperSize,
             Rect visibleRawWallpaperRect, float wallpaperZoom) {
         Point screenSize = ScreenSizeCalculator.getInstance().getScreenSize(display);
         Point defaultCropSize = WallpaperCropUtils.getDefaultCropSurfaceSize(
                 context.getResources(), display);
         return calculateCropRect(context, screenSize, defaultCropSize, rawWallpaperSize,
                 visibleRawWallpaperRect, wallpaperZoom);
     }

     /**
      * Calculates {@link Rect} of the wallpaper which we want to crop to in physical pixel terms
      * (i.e., scaled to current zoom).
      *
      * @param hostViewSize            the size of the view hosting the wallpaper as a Point (x,y).
      * @param cropSize                the default size of the crop as a Point (x,y).
      * @param rawWallpaperSize        the size of the raw wallpaper as a Point (x,y).
      * @param visibleRawWallpaperRect the area of the raw wallpaper which is expected to see.
      * @param wallpaperZoom           the factor which is used to scale the raw wallpaper.
      */
     public static Rect calculateCropRect(Context context, Point hostViewSize, Point cropSize,
             Point rawWallpaperSize, Rect visibleRawWallpaperRect, float wallpaperZoom) {
         int scrollX = (int) (visibleRawWallpaperRect.left * wallpaperZoom);
         int scrollY = (int) (visibleRawWallpaperRect.top * wallpaperZoom);

         return calculateCropRect(context, wallpaperZoom, rawWallpaperSize, cropSize, hostViewSize,
                 scrollX, scrollY);
     }

     /**
      * Resize the wallpaper size so it's new size fits in a outWidth by outHeight rectangle.
      *
      * @param wallpaperSize Rectangle with the current wallpaper size. It will be resized.
      * @param outWidth      the width of the rectangle in which the wallpaperSize needs to fit.
      * @param outHeight     the height of the rectangle in which the wallpaperSize needs to fit.
      */
     public static void fitToSize(Rect wallpaperSize, int outWidth, int outHeight) {
         if (wallpaperSize.isEmpty()) {
             return;
         }
         float maxSizeOut = Math.max(outWidth, outHeight);
         float maxSizeIn = Math.max(wallpaperSize.width(), wallpaperSize.height());
         float scale = maxSizeOut / maxSizeIn;

         // Scale the wallpaper size
         if (scale != 1.0f) {
             wallpaperSize.left = (int) (wallpaperSize.left * scale + 0.5f);
             wallpaperSize.top = (int) (wallpaperSize.top * scale + 0.5f);
             wallpaperSize.right = (int) (wallpaperSize.right * scale + 0.5f);
             wallpaperSize.bottom = (int) (wallpaperSize.bottom * scale + 0.5f);
         }
     }

     /**
      * Get the system wallpaper's maximum scale value.
      */
     public static float getSystemWallpaperMaximumScale(Context context) {
         return WallpaperManagerCompat.getWallpaperZoomOutMaxScale(context);
     }

     /**
      * 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.
      */
     public static boolean isRtl(Context context) {
         return context.getResources().getConfiguration().getLayoutDirection()
                 == View.LAYOUT_DIRECTION_RTL;
     }

     /**
      * Gets the scale of screen size and crop rect real size
      *
      * @param wallpaperScale The scale of crop rect and real size rect
      * @param cropRect The area wallpaper cropped
      * @param screenWidth  The width of screen size
      * @param screenHeight The height of screen size
      */
     public static float getScaleOfScreenResolution(float wallpaperScale, Rect cropRect,
             int screenWidth, int screenHeight) {
         int rectRealWidth = Math.round((float) cropRect.width() / wallpaperScale);
         int rectRealHeight = Math.round((float) cropRect.height() / wallpaperScale);
         int cropWidth = cropRect.width();
         int cropHeight = cropRect.height();
         // Not scale with screen resolution because cropRect is bigger than screen size.
         if (cropWidth >= screenWidth || cropHeight >= screenHeight) {
             return 1;
         }

         int newWidth = screenWidth;
         int newHeight = screenHeight;
         // Screen size is bigger than crop real size so we only need enlarge to real size
         if (newWidth > rectRealWidth || newHeight > rectRealHeight) {
             newWidth = rectRealWidth;
             newHeight = rectRealWidth;
         }
         return Math.min((float) newWidth / cropWidth, (float) newHeight / cropHeight);
     }
 }
	/*
	* 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.util;

	import android.content.Context;
	import android.content.res.Resources;
	import android.graphics.Point;
	import android.graphics.PointF;
	import android.graphics.Rect;
	import android.os.Build.VERSION;
	import android.os.Build.VERSION_CODES;
	import android.view.Display;
	import android.view.View;

	import com.android.systemui.shared.system.WallpaperManagerCompat;

	/**
	* Static utility methods for wallpaper cropping operations.
	*/
	public final class WallpaperCropUtils {

	private static final float WALLPAPER_SCREENS_SPAN = 2f;
	private static final float ASPECT_RATIO_LANDSCAPE = 16 / 10f;
	private static final float ASPECT_RATIO_PORTRAIT = 10 / 16f;
	private static final float WALLPAPER_WIDTH_TO_SCREEN_RATIO_LANDSCAPE = 1.2f;
	private static final float WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT = 1.5f;

	// Suppress default constructor for noninstantiability.
	private WallpaperCropUtils() {
	throw new AssertionError();
	}

	/**
	* Calculates parallax travel (i.e., extra width) for a screen with the given resolution.
	*/
	public static float wallpaperTravelToScreenWidthRatio(int width, int height) {
	float aspectRatio = width / (float) height;

	// At an aspect ratio of 16/10, the wallpaper parallax effect should span 1.2 * screen width
	// At an aspect ratio of 10/16, the wallpaper parallax effect should span 1.5 * screen width
	// We will use these two data points to extrapolate how much the wallpaper parallax effect
	// to span (i.e., travel) at any aspect ratio. We use the following two linear formulas,
	// where
	// the coefficient on x is the aspect ratio (width/height):
	// (16/10)x + y = 1.2
	// (10/16)x + y = 1.5
	// We solve for x and y and end up with a final formula:
	float x = (WALLPAPER_WIDTH_TO_SCREEN_RATIO_LANDSCAPE
	- WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT)
	/ (ASPECT_RATIO_LANDSCAPE - ASPECT_RATIO_PORTRAIT);
	float y = WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT - x * ASPECT_RATIO_PORTRAIT;
	return x * aspectRatio + y;
	}

	/**
	* Calculates ideal crop surface size for a device such that there is room for parallax in both
	* landscape and portrait screen orientations.
	*/
	public static Point getDefaultCropSurfaceSize(Resources resources, Display display) {
	Point minDims = new Point();
	Point maxDims = new Point();
	display.getCurrentSizeRange(minDims, maxDims);

	int maxDim = Math.max(maxDims.x, maxDims.y);
	int minDim = Math.max(minDims.x, minDims.y);

	if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN_MR1) {
	Point realSize = new Point();
	display.getRealSize(realSize);
	maxDim = Math.max(realSize.x, realSize.y);
	minDim = Math.min(realSize.x, realSize.y);
	}

	return calculateCropSurfaceSize(resources, maxDim, minDim, display.getWidth(),
	display.getHeight());
	}

	/**
	* Calculates ideal crop surface size for a surface of dimensions maxDim x minDim such that
	* there is room for parallax in both* landscape and portrait screen orientations.
	*/
	public static Point calculateCropSurfaceSize(Resources resources, int maxDim, int minDim,
	int width, int height) {
	final int defaultWidth, defaultHeight;
	if (resources.getConfiguration().smallestScreenWidthDp >= 720) {
	defaultWidth = (int) (maxDim * wallpaperTravelToScreenWidthRatio(maxDim, minDim));
	} else {
	defaultWidth = Math.max((int) (minDim * WALLPAPER_SCREENS_SPAN), maxDim);
	}
	defaultHeight = width < height ? maxDim : minDim;

	return new Point(defaultWidth, defaultHeight);
	}

	/**
	* Calculates the relative position between an outer and inner rectangle when the outer one is
	* center-cropped to the inner one.
	*
	* @param outer Size of outer rectangle as a Point (x,y).
	* @param inner Size of inner rectangle as a Point (x,y).
	* @param alignStart Whether the inner rectangle should be aligned to the start of the layout
	* with the outer one and ignore horizontal centering.
	* @param isRtl Whether the layout direction is RTL (or false for LTR).
	* @return Position relative to the top left corner of the outer rectangle, where the size of
	* each rectangle is represented by Points, in coordinates (x,y) relative to the outer rectangle
	* where the top left corner is (0,0)
	* @throws IllegalArgumentException if inner rectangle is not contained within outer rectangle
	* which would return a position with at least one negative
	* coordinate.
	*/
	public static Point calculateCenterPosition(Point outer, Point inner, boolean alignStart,
	boolean isRtl) {
	if (inner.x > outer.x \|\| inner.y > outer.y) {
	throw new IllegalArgumentException("Inner rectangle " + inner + " should be contained"
	+ " completely within the outer rectangle " + outer + ".");
	}

	Point relativePosition = new Point();

	if (alignStart) {
	relativePosition.x = isRtl ? outer.x - inner.x : 0;
	} else {
	relativePosition.x = Math.round((outer.x - inner.x) / 2f);
	}
	relativePosition.y = Math.round((outer.y - inner.y) / 2f);

	return relativePosition;
	}

	/**
	* Calculates the minimum zoom such that the maximum surface area of the outer rectangle is
	* visible within the inner rectangle.
	*
	* @param outer Size of outer rectangle as a Point (x,y).
	* @param inner Size of inner rectangle as a Point (x,y).
	*/
	public static float calculateMinZoom(Point outer, Point inner) {
	float minZoom;
	if (inner.x / (float) inner.y > outer.x / (float) outer.y) {
	minZoom = inner.x / (float) outer.x;
	} else {
	minZoom = inner.y / (float) outer.y;
	}
	return minZoom;
	}


	/**
	* Calculates the center position of a wallpaper of the given size, based on a "crop surface"
	* (with extra width to account for parallax) superimposed on the screen. Trying to show as
	* much of the wallpaper as possible on the crop surface and align screen to crop surface such
	* that the centered wallpaper matches what would be seen by the user in the left-most home
	* screen.
	*
	* @param wallpaperSize full size of the wallpaper
	* @param visibleWallpaperRect visible area available for the wallpaper
	* @return a point corresponding to the position of wallpaper that should be in the center
	* of the screen.
	*/
	public static PointF calculateDefaultCenter(Context context, Point wallpaperSize,
	Rect visibleWallpaperRect) {

	WallpaperCropUtils.adjustCurrentWallpaperCropRect(context, wallpaperSize,
	visibleWallpaperRect);

	return new PointF(visibleWallpaperRect.centerX(),
	visibleWallpaperRect.centerY());
	}

	/**
	* Calculates the rectangle to crop a wallpaper of the given size, and considering the given
	* scrollX and scrollY offsets
	* @param wallpaperZoom zoom applied to the raw wallpaper image
	* @param wallpaperSize full ("raw") wallpaper size
	* @param defaultCropSurfaceSize @see #getDefaultCropSurfaceSize(Resources, Display)
	* @param targetHostSize target size where the wallpaper will be rendered (eg, the display size)
	* @param scrollX x-axis offset the cropping area from the wallpaper's 0,0 position
	* @param scrollY y-axis offset the cropping area from the wallpaper's 0,0 position
	* @return a Rect representing the area of the wallpaper to crop.
	*/
	public static Rect calculateCropRect(Context context, float wallpaperZoom, Point wallpaperSize,
	Point defaultCropSurfaceSize, Point targetHostSize, int scrollX, int scrollY) {
	// Calculate Rect of wallpaper in physical pixel terms (i.e., scaled to current zoom).
	int scaledWallpaperWidth = Math.round(wallpaperSize.x * wallpaperZoom);
	int scaledWallpaperHeight = Math.round(wallpaperSize.y * wallpaperZoom);
	Rect rect = new Rect();
	rect.set(0, 0, scaledWallpaperWidth, scaledWallpaperHeight);

	// Crop rect should start off as the visible screen and then include extra width and height
	// if available within wallpaper at the current zoom.
	Rect cropRect = new Rect(scrollX, scrollY, scrollX + targetHostSize.x,
	scrollY + targetHostSize.y);

	int extraWidth = defaultCropSurfaceSize.x - targetHostSize.x;
	int extraHeightTopAndBottom = (int) ((defaultCropSurfaceSize.y - targetHostSize.y) / 2f);

	// Try to increase size of screenRect to include extra width depending on the layout
	// direction.
	if (isRtl(context)) {
	cropRect.left = Math.max(cropRect.left - extraWidth, rect.left);
	} else {
	cropRect.right = Math.min(cropRect.right + extraWidth, rect.right);
	}

	// Try to increase the size of the cropRect to to include extra height.
	int availableExtraHeightTop = cropRect.top - Math.max(
	rect.top,
	cropRect.top - extraHeightTopAndBottom);
	int availableExtraHeightBottom = Math.min(
	rect.bottom,
	cropRect.bottom + extraHeightTopAndBottom) - cropRect.bottom;

	int availableExtraHeightTopAndBottom =
	Math.min(availableExtraHeightTop, availableExtraHeightBottom);
	cropRect.top -= availableExtraHeightTopAndBottom;
	cropRect.bottom += availableExtraHeightTopAndBottom;

	return cropRect;
	}

	/**
	* Calculates the center area of the outer rectangle which is visible in the inner rectangle
	* after applying the minimum zoom.
	*
	* @param outer the size of outer rectangle as a Point (x,y).
	* @param inner the size of inner rectangle as a Point (x,y).
	*/
	public static Rect calculateVisibleRect(Point outer, Point inner) {
	PointF visibleRectCenter = new PointF(outer.x / 2f, outer.y / 2f);
	if (inner.x / (float) inner.y > outer.x / (float) outer.y) {
	float minZoom = inner.x / (float) outer.x;
	float visibleRectHeight = inner.y / minZoom;
	return new Rect(0, (int) (visibleRectCenter.y - visibleRectHeight / 2),
	outer.x, (int) (visibleRectCenter.y + visibleRectHeight / 2));
	} else {
	float minZoom = inner.y / (float) outer.y;
	float visibleRectWidth = inner.x / minZoom;
	return new Rect((int) (visibleRectCenter.x - visibleRectWidth / 2),
	0, (int) (visibleRectCenter.x + visibleRectWidth / 2), outer.y);
	}
	}

	public static void adjustCurrentWallpaperCropRect(Context context, Point assetDimensions,
	Rect cropRect) {
	adjustCropRect(context, cropRect, true /* zoomIn */);
	}

	/** Adjust the crop rect by zooming in with systemWallpaperMaxScale. */
	public static void adjustCropRect(Context context, Rect cropRect, boolean zoomIn) {
	float centerX = cropRect.centerX();
	float centerY = cropRect.centerY();
	float width = cropRect.width();
	float height = cropRect.height();
	float systemWallpaperMaxScale = getSystemWallpaperMaximumScale(context);
	float scale = zoomIn ? systemWallpaperMaxScale : 1.0f / systemWallpaperMaxScale;

	// Adjust the rect according to the system wallpaper's maximum scale.
	int left = (int) (centerX - (width / 2) / scale);
	int top = (int) (centerY - (height / 2) / scale);
	int right = (int) (centerX + (width / 2) / scale);
	int bottom = (int) (centerY + (height / 2) / scale);
	cropRect.set(left, top, right, bottom);
	}

	/** Adjust the given Point, representing a size by systemWallpaperMaxScale. */
	public static void scaleSize(Context context, Point size) {
	float systemWallpaperMaxScale = getSystemWallpaperMaximumScale(context);
	size.set((int) (size.x * systemWallpaperMaxScale),
	(int) (size.y * systemWallpaperMaxScale));
	}
	/**
	* Calculates {@link Rect} of the wallpaper which we want to crop to in physical pixel terms
	* (i.e., scaled to current zoom) when the wallpaper is laid on a fullscreen view.
	*/
	public static Rect calculateCropRect(Context context, Display display, Point rawWallpaperSize,
	Rect visibleRawWallpaperRect, float wallpaperZoom) {
	Point screenSize = ScreenSizeCalculator.getInstance().getScreenSize(display);
	Point defaultCropSize = WallpaperCropUtils.getDefaultCropSurfaceSize(
	context.getResources(), display);
	return calculateCropRect(context, screenSize, defaultCropSize, rawWallpaperSize,
	visibleRawWallpaperRect, wallpaperZoom);
	}

	/**
	* Calculates {@link Rect} of the wallpaper which we want to crop to in physical pixel terms
	* (i.e., scaled to current zoom).
	*
	* @param hostViewSize the size of the view hosting the wallpaper as a Point (x,y).
	* @param cropSize the default size of the crop as a Point (x,y).
	* @param rawWallpaperSize the size of the raw wallpaper as a Point (x,y).
	* @param visibleRawWallpaperRect the area of the raw wallpaper which is expected to see.
	* @param wallpaperZoom the factor which is used to scale the raw wallpaper.
	*/
	public static Rect calculateCropRect(Context context, Point hostViewSize, Point cropSize,
	Point rawWallpaperSize, Rect visibleRawWallpaperRect, float wallpaperZoom) {
	int scrollX = (int) (visibleRawWallpaperRect.left * wallpaperZoom);
	int scrollY = (int) (visibleRawWallpaperRect.top * wallpaperZoom);

	return calculateCropRect(context, wallpaperZoom, rawWallpaperSize, cropSize, hostViewSize,
	scrollX, scrollY);
	}

	/**
	* Resize the wallpaper size so it's new size fits in a outWidth by outHeight rectangle.
	*
	* @param wallpaperSize Rectangle with the current wallpaper size. It will be resized.
	* @param outWidth the width of the rectangle in which the wallpaperSize needs to fit.
	* @param outHeight the height of the rectangle in which the wallpaperSize needs to fit.
	*/
	public static void fitToSize(Rect wallpaperSize, int outWidth, int outHeight) {
	if (wallpaperSize.isEmpty()) {
	return;
	}
	float maxSizeOut = Math.max(outWidth, outHeight);
	float maxSizeIn = Math.max(wallpaperSize.width(), wallpaperSize.height());
	float scale = maxSizeOut / maxSizeIn;

	// Scale the wallpaper size
	if (scale != 1.0f) {
	wallpaperSize.left = (int) (wallpaperSize.left * scale + 0.5f);
	wallpaperSize.top = (int) (wallpaperSize.top * scale + 0.5f);
	wallpaperSize.right = (int) (wallpaperSize.right * scale + 0.5f);
	wallpaperSize.bottom = (int) (wallpaperSize.bottom * scale + 0.5f);
	}
	}

	/**
	* Get the system wallpaper's maximum scale value.
	*/
	public static float getSystemWallpaperMaximumScale(Context context) {
	return WallpaperManagerCompat.getWallpaperZoomOutMaxScale(context);
	}

	/**
	* 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.
	*/
	public static boolean isRtl(Context context) {
	return context.getResources().getConfiguration().getLayoutDirection()
	== View.LAYOUT_DIRECTION_RTL;
	}

	/**
	* Gets the scale of screen size and crop rect real size
	*
	* @param wallpaperScale The scale of crop rect and real size rect
	* @param cropRect The area wallpaper cropped
	* @param screenWidth The width of screen size
	* @param screenHeight The height of screen size
	*/
	public static float getScaleOfScreenResolution(float wallpaperScale, Rect cropRect,
	int screenWidth, int screenHeight) {
	int rectRealWidth = Math.round((float) cropRect.width() / wallpaperScale);
	int rectRealHeight = Math.round((float) cropRect.height() / wallpaperScale);
	int cropWidth = cropRect.width();
	int cropHeight = cropRect.height();
	// Not scale with screen resolution because cropRect is bigger than screen size.
	if (cropWidth >= screenWidth \|\| cropHeight >= screenHeight) {
	return 1;
	}

	int newWidth = screenWidth;
	int newHeight = screenHeight;
	// Screen size is bigger than crop real size so we only need enlarge to real size
	if (newWidth > rectRealWidth \|\| newHeight > rectRealHeight) {
	newWidth = rectRealWidth;
	newHeight = rectRealWidth;
	}
	return Math.min((float) newWidth / cropWidth, (float) newHeight / cropHeight);
	}
	}