src/com/android/launcher3/Utilities.java - platform/packages/apps/Launcher3 - Git at Google

 /*
  * Copyright (C) 2008 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.launcher3;

 import android.app.Activity;
 import android.content.ActivityNotFoundException;
 import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.ResolveInfo;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Matrix;
 import android.graphics.Paint;
 import android.graphics.PaintFlagsDrawFilter;
 import android.graphics.Rect;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.PaintDrawable;
 import android.os.Build;
 import android.util.Log;
 import android.util.Pair;
 import android.util.SparseArray;
 import android.view.View;
 import android.widget.Toast;

 import java.util.ArrayList;

 /**
  * Various utilities shared amongst the Launcher's classes.
  */
 public final class Utilities {
     private static final String TAG = "Launcher.Utilities";

     private static int sIconWidth = -1;
     private static int sIconHeight = -1;
     public static int sIconTextureWidth = -1;
     public static int sIconTextureHeight = -1;

     private static final Rect sOldBounds = new Rect();
     private static final Canvas sCanvas = new Canvas();

     static {
         sCanvas.setDrawFilter(new PaintFlagsDrawFilter(Paint.DITHER_FLAG,
                 Paint.FILTER_BITMAP_FLAG));
     }
     static int sColors[] = { 0xffff0000, 0xff00ff00, 0xff0000ff };
     static int sColorIndex = 0;

     static int[] sLoc0 = new int[2];
     static int[] sLoc1 = new int[2];

     // To turn on these properties, type
     // adb shell setprop log.tag.PROPERTY_NAME [VERBOSE | SUPPRESS]
     static final String FORCE_ENABLE_ROTATION_PROPERTY = "launcher_force_rotate";
     public static boolean sForceEnableRotation = isPropertyEnabled(FORCE_ENABLE_ROTATION_PROPERTY);

     /**
      * Returns a FastBitmapDrawable with the icon, accurately sized.
      */
     public static FastBitmapDrawable createIconDrawable(Bitmap icon) {
         FastBitmapDrawable d = new FastBitmapDrawable(icon);
         d.setFilterBitmap(true);
         resizeIconDrawable(d);
         return d;
     }

     /**
      * Resizes an icon drawable to the correct icon size.
      */
     static void resizeIconDrawable(Drawable icon) {
         icon.setBounds(0, 0, sIconTextureWidth, sIconTextureHeight);
     }

     private static boolean isPropertyEnabled(String propertyName) {
         return Log.isLoggable(propertyName, Log.VERBOSE);
     }

     public static boolean isRotationEnabled(Context c) {
         boolean enableRotation = sForceEnableRotation ||
                 c.getResources().getBoolean(R.bool.allow_rotation);
         return enableRotation;
     }

     /**
      * Indicates if the device is running LMP or higher.
      */
     public static boolean isLmpOrAbove() {
         return Build.VERSION.SDK_INT >= Build.VERSION_CODES.L;
     }

     /**
      * Returns a bitmap suitable for the all apps view. Used to convert pre-ICS
      * icon bitmaps that are stored in the database (which were 74x74 pixels at hdpi size)
      * to the proper size (48dp)
      */
     static Bitmap createIconBitmap(Bitmap icon, Context context) {
         int textureWidth = sIconTextureWidth;
         int textureHeight = sIconTextureHeight;
         int sourceWidth = icon.getWidth();
         int sourceHeight = icon.getHeight();
         if (sourceWidth > textureWidth && sourceHeight > textureHeight) {
             // Icon is bigger than it should be; clip it (solves the GB->ICS migration case)
             return Bitmap.createBitmap(icon,
                     (sourceWidth - textureWidth) / 2,
                     (sourceHeight - textureHeight) / 2,
                     textureWidth, textureHeight);
         } else if (sourceWidth == textureWidth && sourceHeight == textureHeight) {
             // Icon is the right size, no need to change it
             return icon;
         } else {
             // Icon is too small, render to a larger bitmap
             final Resources resources = context.getResources();
             return createIconBitmap(new BitmapDrawable(resources, icon), context);
         }
     }

     /**
      * Returns a bitmap suitable for the all apps view.
      */
     public static Bitmap createIconBitmap(Drawable icon, Context context) {
         synchronized (sCanvas) { // we share the statics :-(
             if (sIconWidth == -1) {
                 initStatics(context);
             }

             int width = sIconWidth;
             int height = sIconHeight;

             if (icon instanceof PaintDrawable) {
                 PaintDrawable painter = (PaintDrawable) icon;
                 painter.setIntrinsicWidth(width);
                 painter.setIntrinsicHeight(height);
             } else if (icon instanceof BitmapDrawable) {
                 // Ensure the bitmap has a density.
                 BitmapDrawable bitmapDrawable = (BitmapDrawable) icon;
                 Bitmap bitmap = bitmapDrawable.getBitmap();
                 if (bitmap.getDensity() == Bitmap.DENSITY_NONE) {
                     bitmapDrawable.setTargetDensity(context.getResources().getDisplayMetrics());
                 }
             }
             int sourceWidth = icon.getIntrinsicWidth();
             int sourceHeight = icon.getIntrinsicHeight();
             if (sourceWidth > 0 && sourceHeight > 0) {
                 // Scale the icon proportionally to the icon dimensions
                 final float ratio = (float) sourceWidth / sourceHeight;
                 if (sourceWidth > sourceHeight) {
                     height = (int) (width / ratio);
                 } else if (sourceHeight > sourceWidth) {
                     width = (int) (height * ratio);
                 }
             }

             // no intrinsic size --> use default size
             int textureWidth = sIconTextureWidth;
             int textureHeight = sIconTextureHeight;

             final Bitmap bitmap = Bitmap.createBitmap(textureWidth, textureHeight,
                     Bitmap.Config.ARGB_8888);
             final Canvas canvas = sCanvas;
             canvas.setBitmap(bitmap);

             final int left = (textureWidth-width) / 2;
             final int top = (textureHeight-height) / 2;

             @SuppressWarnings("all") // suppress dead code warning
             final boolean debug = false;
             if (debug) {
                 // draw a big box for the icon for debugging
                 canvas.drawColor(sColors[sColorIndex]);
                 if (++sColorIndex >= sColors.length) sColorIndex = 0;
                 Paint debugPaint = new Paint();
                 debugPaint.setColor(0xffcccc00);
                 canvas.drawRect(left, top, left+width, top+height, debugPaint);
             }

             sOldBounds.set(icon.getBounds());
             icon.setBounds(left, top, left+width, top+height);
             icon.draw(canvas);
             icon.setBounds(sOldBounds);
             canvas.setBitmap(null);

             return bitmap;
         }
     }

     /**
      * Returns a Bitmap representing the thumbnail of the specified Bitmap.
      *
      * @param bitmap The bitmap to get a thumbnail of.
      * @param context The application's context.
      *
      * @return A thumbnail for the specified bitmap or the bitmap itself if the
      *         thumbnail could not be created.
      */
     static Bitmap resampleIconBitmap(Bitmap bitmap, Context context) {
         synchronized (sCanvas) { // we share the statics :-(
             if (sIconWidth == -1) {
                 initStatics(context);
             }

             if (bitmap.getWidth() == sIconWidth && bitmap.getHeight() == sIconHeight) {
                 return bitmap;
             } else {
                 final Resources resources = context.getResources();
                 return createIconBitmap(new BitmapDrawable(resources, bitmap), context);
             }
         }
     }

     /**
      * Given a coordinate relative to the descendant, find the coordinate in a parent view's
      * coordinates.
      *
      * @param descendant The descendant to which the passed coordinate is relative.
      * @param root The root view to make the coordinates relative to.
      * @param coord The coordinate that we want mapped.
      * @param includeRootScroll Whether or not to account for the scroll of the descendant:
      *          sometimes this is relevant as in a child's coordinates within the descendant.
      * @return The factor by which this descendant is scaled relative to this DragLayer. Caution
      *         this scale factor is assumed to be equal in X and Y, and so if at any point this
      *         assumption fails, we will need to return a pair of scale factors.
      */
     public static float getDescendantCoordRelativeToParent(View descendant, View root,
                                                            int[] coord, boolean includeRootScroll) {
         ArrayList<View> ancestorChain = new ArrayList<View>();

         float[] pt = {coord[0], coord[1]};

         View v = descendant;
         while(v != root && v != null) {
             ancestorChain.add(v);
             v = (View) v.getParent();
         }
         ancestorChain.add(root);

         float scale = 1.0f;
         int count = ancestorChain.size();
         for (int i = 0; i < count; i++) {
             View v0 = ancestorChain.get(i);
             // For TextViews, scroll has a meaning which relates to the text position
             // which is very strange... ignore the scroll.
             if (v0 != descendant || includeRootScroll) {
                 pt[0] -= v0.getScrollX();
                 pt[1] -= v0.getScrollY();
             }

             v0.getMatrix().mapPoints(pt);
             pt[0] += v0.getLeft();
             pt[1] += v0.getTop();
             scale *= v0.getScaleX();
         }

         coord[0] = (int) Math.round(pt[0]);
         coord[1] = (int) Math.round(pt[1]);
         return scale;
     }

     /**
      * Inverse of {@link #getDescendantCoordRelativeToSelf(View, int[])}.
      */
     public static float mapCoordInSelfToDescendent(View descendant, View root,
                                                    int[] coord) {
         ArrayList<View> ancestorChain = new ArrayList<View>();

         float[] pt = {coord[0], coord[1]};

         View v = descendant;
         while(v != root) {
             ancestorChain.add(v);
             v = (View) v.getParent();
         }
         ancestorChain.add(root);

         float scale = 1.0f;
         Matrix inverse = new Matrix();
         int count = ancestorChain.size();
         for (int i = count - 1; i >= 0; i--) {
             View ancestor = ancestorChain.get(i);
             View next = i > 0 ? ancestorChain.get(i-1) : null;

             pt[0] += ancestor.getScrollX();
             pt[1] += ancestor.getScrollY();

             if (next != null) {
                 pt[0] -= next.getLeft();
                 pt[1] -= next.getTop();
                 next.getMatrix().invert(inverse);
                 inverse.mapPoints(pt);
                 scale *= next.getScaleX();
             }
         }

         coord[0] = (int) Math.round(pt[0]);
         coord[1] = (int) Math.round(pt[1]);
         return scale;
     }

     /**
      * Utility method to determine whether the given point, in local coordinates,
      * is inside the view, where the area of the view is expanded by the slop factor.
      * This method is called while processing touch-move events to determine if the event
      * is still within the view.
      */
     public static boolean pointInView(View v, float localX, float localY, float slop) {
         return localX >= -slop && localY >= -slop && localX < (v.getWidth() + slop) &&
                 localY < (v.getHeight() + slop);
     }

     private static void initStatics(Context context) {
         final Resources resources = context.getResources();
         sIconWidth = sIconHeight = (int) resources.getDimension(R.dimen.app_icon_size);
         sIconTextureWidth = sIconTextureHeight = sIconWidth;
     }

     public static void setIconSize(int widthPx) {
         sIconWidth = sIconHeight = widthPx;
         sIconTextureWidth = sIconTextureHeight = widthPx;
     }

     public static void scaleRect(Rect r, float scale) {
         if (scale != 1.0f) {
             r.left = (int) (r.left * scale + 0.5f);
             r.top = (int) (r.top * scale + 0.5f);
             r.right = (int) (r.right * scale + 0.5f);
             r.bottom = (int) (r.bottom * scale + 0.5f);
         }
     }

     public static int[] getCenterDeltaInScreenSpace(View v0, View v1, int[] delta) {
         v0.getLocationInWindow(sLoc0);
         v1.getLocationInWindow(sLoc1);

         sLoc0[0] += (v0.getMeasuredWidth() * v0.getScaleX()) / 2;
         sLoc0[1] += (v0.getMeasuredHeight() * v0.getScaleY()) / 2;
         sLoc1[0] += (v1.getMeasuredWidth() * v1.getScaleX()) / 2;
         sLoc1[1] += (v1.getMeasuredHeight() * v1.getScaleY()) / 2;

         if (delta == null) {
             delta = new int[2];
         }

         delta[0] = sLoc1[0] - sLoc0[0];
         delta[1] = sLoc1[1] - sLoc0[1];

         return delta;
     }

     public static void scaleRectAboutCenter(Rect r, float scale) {
         int cx = r.centerX();
         int cy = r.centerY();
         r.offset(-cx, -cy);
         Utilities.scaleRect(r, scale);
         r.offset(cx, cy);
     }

     public static void startActivityForResultSafely(
             Activity activity, Intent intent, int requestCode) {
         try {
             activity.startActivityForResult(intent, requestCode);
         } catch (ActivityNotFoundException e) {
             Toast.makeText(activity, R.string.activity_not_found, Toast.LENGTH_SHORT).show();
         } catch (SecurityException e) {
             Toast.makeText(activity, R.string.activity_not_found, Toast.LENGTH_SHORT).show();
             Log.e(TAG, "Launcher does not have the permission to launch " + intent +
                     ". Make sure to create a MAIN intent-filter for the corresponding activity " +
                     "or use the exported attribute for this activity.", e);
         }
     }

     static boolean isSystemApp(Context context, Intent intent) {
         PackageManager pm = context.getPackageManager();
         ComponentName cn = intent.getComponent();
         String packageName = null;
         if (cn == null) {
             ResolveInfo info = pm.resolveActivity(intent, PackageManager.MATCH_DEFAULT_ONLY);
             if ((info != null) && (info.activityInfo != null)) {
                 packageName = info.activityInfo.packageName;
             }
         } else {
             packageName = cn.getPackageName();
         }
         if (packageName != null) {
             try {
                 PackageInfo info = pm.getPackageInfo(packageName, 0);
                 return (info != null) && (info.applicationInfo != null) &&
                         ((info.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0);
             } catch (NameNotFoundException e) {
                 return false;
             }
         } else {
             return false;
         }
     }

     /**
      * This picks a dominant color, looking for high-saturation, high-value, repeated hues.
      * @param bitmap The bitmap to scan
      * @param samples The approximate max number of samples to use.
      */
     static int findDominantColorByHue(Bitmap bitmap, int samples) {
         final int height = bitmap.getHeight();
         final int width = bitmap.getWidth();
         int sampleStride = (int) Math.sqrt((height * width) / samples);
         if (sampleStride < 1) {
             sampleStride = 1;
         }

         // This is an out-param, for getting the hsv values for an rgb
         float[] hsv = new float[3];

         // First get the best hue, by creating a histogram over 360 hue buckets,
         // where each pixel contributes a score weighted by saturation, value, and alpha.
         float[] hueScoreHistogram = new float[360];
         float highScore = -1;
         int bestHue = -1;

         for (int y = 0; y < height; y += sampleStride) {
             for (int x = 0; x < width; x += sampleStride) {
                 int argb = bitmap.getPixel(x, y);
                 int alpha = 0xFF & (argb >> 24);
                 if (alpha < 0x80) {
                     // Drop mostly-transparent pixels.
                     continue;
                 }
                 // Remove the alpha channel.
                 int rgb = argb | 0xFF000000;
                 Color.colorToHSV(rgb, hsv);
                 // Bucket colors by the 360 integer hues.
                 int hue = (int) hsv[0];
                 if (hue < 0 || hue >= hueScoreHistogram.length) {
                     // Defensively avoid array bounds violations.
                     continue;
                 }
                 float score = hsv[1] * hsv[2];
                 hueScoreHistogram[hue] += score;
                 if (hueScoreHistogram[hue] > highScore) {
                     highScore = hueScoreHistogram[hue];
                     bestHue = hue;
                 }
             }
         }

         SparseArray<Float> rgbScores = new SparseArray<Float>();
         int bestColor = 0xff000000;
         highScore = -1;
         // Go back over the RGB colors that match the winning hue,
         // creating a histogram of weighted s*v scores, for up to 100*100 [s,v] buckets.
         // The highest-scoring RGB color wins.
         for (int y = 0; y < height; y += sampleStride) {
             for (int x = 0; x < width; x += sampleStride) {
                 int rgb = bitmap.getPixel(x, y) | 0xff000000;
                 Color.colorToHSV(rgb, hsv);
                 int hue = (int) hsv[0];
                 if (hue == bestHue) {
                     float s = hsv[1];
                     float v = hsv[2];
                     int bucket = (int) (s * 100) + (int) (v * 10000);
                     // Score by cumulative saturation * value.
                     float score = s * v;
                     Float oldTotal = rgbScores.get(bucket);
                     float newTotal = oldTotal == null ? score : oldTotal + score;
                     rgbScores.put(bucket, newTotal);
                     if (newTotal > highScore) {
                         highScore = newTotal;
                         // All the colors in the winning bucket are very similar. Last in wins.
                         bestColor = rgb;
                     }
                 }
             }
         }
         return bestColor;
     }

     /*
      * Finds a system apk which had a broadcast receiver listening to a particular action.
      * @param action intent action used to find the apk
      * @return a pair of apk package name and the resources.
      */
     static Pair<String, Resources> findSystemApk(String action, PackageManager pm) {
         final Intent intent = new Intent(action);
         for (ResolveInfo info : pm.queryBroadcastReceivers(intent, 0)) {
             if (info.activityInfo != null &&
                     (info.activityInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0) {
                 final String packageName = info.activityInfo.packageName;
                 try {
                     final Resources res = pm.getResourcesForApplication(packageName);
                     return Pair.create(packageName, res);
                 } catch (NameNotFoundException e) {
                     Log.w(TAG, "Failed to find resources for " + packageName);
                 }
             }
         }
         return null;
     }
 }
	/*
	* Copyright (C) 2008 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.launcher3;

	import android.app.Activity;
	import android.content.ActivityNotFoundException;
	import android.content.ComponentName;
	import android.content.Context;
	import android.content.Intent;
	import android.content.pm.ApplicationInfo;
	import android.content.pm.PackageInfo;
	import android.content.pm.PackageManager;
	import android.content.pm.PackageManager.NameNotFoundException;
	import android.content.pm.ResolveInfo;
	import android.content.res.Resources;
	import android.graphics.Bitmap;
	import android.graphics.Canvas;
	import android.graphics.Color;
	import android.graphics.Matrix;
	import android.graphics.Paint;
	import android.graphics.PaintFlagsDrawFilter;
	import android.graphics.Rect;
	import android.graphics.drawable.BitmapDrawable;
	import android.graphics.drawable.Drawable;
	import android.graphics.drawable.PaintDrawable;
	import android.os.Build;
	import android.util.Log;
	import android.util.Pair;
	import android.util.SparseArray;
	import android.view.View;
	import android.widget.Toast;

	import java.util.ArrayList;

	/**
	* Various utilities shared amongst the Launcher's classes.
	*/
	public final class Utilities {
	private static final String TAG = "Launcher.Utilities";

	private static int sIconWidth = -1;
	private static int sIconHeight = -1;
	public static int sIconTextureWidth = -1;
	public static int sIconTextureHeight = -1;

	private static final Rect sOldBounds = new Rect();
	private static final Canvas sCanvas = new Canvas();

	static {
	sCanvas.setDrawFilter(new PaintFlagsDrawFilter(Paint.DITHER_FLAG,
	Paint.FILTER_BITMAP_FLAG));
	}
	static int sColors[] = { 0xffff0000, 0xff00ff00, 0xff0000ff };
	static int sColorIndex = 0;

	static int[] sLoc0 = new int[2];
	static int[] sLoc1 = new int[2];

	// To turn on these properties, type
	// adb shell setprop log.tag.PROPERTY_NAME [VERBOSE \| SUPPRESS]
	static final String FORCE_ENABLE_ROTATION_PROPERTY = "launcher_force_rotate";
	public static boolean sForceEnableRotation = isPropertyEnabled(FORCE_ENABLE_ROTATION_PROPERTY);

	/**
	* Returns a FastBitmapDrawable with the icon, accurately sized.
	*/
	public static FastBitmapDrawable createIconDrawable(Bitmap icon) {
	FastBitmapDrawable d = new FastBitmapDrawable(icon);
	d.setFilterBitmap(true);
	resizeIconDrawable(d);
	return d;
	}

	/**
	* Resizes an icon drawable to the correct icon size.
	*/
	static void resizeIconDrawable(Drawable icon) {
	icon.setBounds(0, 0, sIconTextureWidth, sIconTextureHeight);
	}

	private static boolean isPropertyEnabled(String propertyName) {
	return Log.isLoggable(propertyName, Log.VERBOSE);
	}

	public static boolean isRotationEnabled(Context c) {
	boolean enableRotation = sForceEnableRotation \|\|
	c.getResources().getBoolean(R.bool.allow_rotation);
	return enableRotation;
	}

	/**
	* Indicates if the device is running LMP or higher.
	*/
	public static boolean isLmpOrAbove() {
	return Build.VERSION.SDK_INT >= Build.VERSION_CODES.L;
	}

	/**
	* Returns a bitmap suitable for the all apps view. Used to convert pre-ICS
	* icon bitmaps that are stored in the database (which were 74x74 pixels at hdpi size)
	* to the proper size (48dp)
	*/
	static Bitmap createIconBitmap(Bitmap icon, Context context) {
	int textureWidth = sIconTextureWidth;
	int textureHeight = sIconTextureHeight;
	int sourceWidth = icon.getWidth();
	int sourceHeight = icon.getHeight();
	if (sourceWidth > textureWidth && sourceHeight > textureHeight) {
	// Icon is bigger than it should be; clip it (solves the GB->ICS migration case)
	return Bitmap.createBitmap(icon,
	(sourceWidth - textureWidth) / 2,
	(sourceHeight - textureHeight) / 2,
	textureWidth, textureHeight);
	} else if (sourceWidth == textureWidth && sourceHeight == textureHeight) {
	// Icon is the right size, no need to change it
	return icon;
	} else {
	// Icon is too small, render to a larger bitmap
	final Resources resources = context.getResources();
	return createIconBitmap(new BitmapDrawable(resources, icon), context);
	}
	}

	/**
	* Returns a bitmap suitable for the all apps view.
	*/
	public static Bitmap createIconBitmap(Drawable icon, Context context) {
	synchronized (sCanvas) { // we share the statics :-(
	if (sIconWidth == -1) {
	initStatics(context);
	}

	int width = sIconWidth;
	int height = sIconHeight;

	if (icon instanceof PaintDrawable) {
	PaintDrawable painter = (PaintDrawable) icon;
	painter.setIntrinsicWidth(width);
	painter.setIntrinsicHeight(height);
	} else if (icon instanceof BitmapDrawable) {
	// Ensure the bitmap has a density.
	BitmapDrawable bitmapDrawable = (BitmapDrawable) icon;
	Bitmap bitmap = bitmapDrawable.getBitmap();
	if (bitmap.getDensity() == Bitmap.DENSITY_NONE) {
	bitmapDrawable.setTargetDensity(context.getResources().getDisplayMetrics());
	}
	}
	int sourceWidth = icon.getIntrinsicWidth();
	int sourceHeight = icon.getIntrinsicHeight();
	if (sourceWidth > 0 && sourceHeight > 0) {
	// Scale the icon proportionally to the icon dimensions
	final float ratio = (float) sourceWidth / sourceHeight;
	if (sourceWidth > sourceHeight) {
	height = (int) (width / ratio);
	} else if (sourceHeight > sourceWidth) {
	width = (int) (height * ratio);
	}
	}

	// no intrinsic size --> use default size
	int textureWidth = sIconTextureWidth;
	int textureHeight = sIconTextureHeight;

	final Bitmap bitmap = Bitmap.createBitmap(textureWidth, textureHeight,
	Bitmap.Config.ARGB_8888);
	final Canvas canvas = sCanvas;
	canvas.setBitmap(bitmap);

	final int left = (textureWidth-width) / 2;
	final int top = (textureHeight-height) / 2;

	@SuppressWarnings("all") // suppress dead code warning
	final boolean debug = false;
	if (debug) {
	// draw a big box for the icon for debugging
	canvas.drawColor(sColors[sColorIndex]);
	if (++sColorIndex >= sColors.length) sColorIndex = 0;
	Paint debugPaint = new Paint();
	debugPaint.setColor(0xffcccc00);
	canvas.drawRect(left, top, left+width, top+height, debugPaint);
	}

	sOldBounds.set(icon.getBounds());
	icon.setBounds(left, top, left+width, top+height);
	icon.draw(canvas);
	icon.setBounds(sOldBounds);
	canvas.setBitmap(null);

	return bitmap;
	}
	}

	/**
	* Returns a Bitmap representing the thumbnail of the specified Bitmap.
	*
	* @param bitmap The bitmap to get a thumbnail of.
	* @param context The application's context.
	*
	* @return A thumbnail for the specified bitmap or the bitmap itself if the
	* thumbnail could not be created.
	*/
	static Bitmap resampleIconBitmap(Bitmap bitmap, Context context) {
	synchronized (sCanvas) { // we share the statics :-(
	if (sIconWidth == -1) {
	initStatics(context);
	}

	if (bitmap.getWidth() == sIconWidth && bitmap.getHeight() == sIconHeight) {
	return bitmap;
	} else {
	final Resources resources = context.getResources();
	return createIconBitmap(new BitmapDrawable(resources, bitmap), context);
	}
	}
	}

	/**
	* Given a coordinate relative to the descendant, find the coordinate in a parent view's
	* coordinates.
	*
	* @param descendant The descendant to which the passed coordinate is relative.
	* @param root The root view to make the coordinates relative to.
	* @param coord The coordinate that we want mapped.
	* @param includeRootScroll Whether or not to account for the scroll of the descendant:
	* sometimes this is relevant as in a child's coordinates within the descendant.
	* @return The factor by which this descendant is scaled relative to this DragLayer. Caution
	* this scale factor is assumed to be equal in X and Y, and so if at any point this
	* assumption fails, we will need to return a pair of scale factors.
	*/
	public static float getDescendantCoordRelativeToParent(View descendant, View root,
	int[] coord, boolean includeRootScroll) {
	ArrayList<View> ancestorChain = new ArrayList<View>();

	float[] pt = {coord[0], coord[1]};

	View v = descendant;
	while(v != root && v != null) {
	ancestorChain.add(v);
	v = (View) v.getParent();
	}
	ancestorChain.add(root);

	float scale = 1.0f;
	int count = ancestorChain.size();
	for (int i = 0; i < count; i++) {
	View v0 = ancestorChain.get(i);
	// For TextViews, scroll has a meaning which relates to the text position
	// which is very strange... ignore the scroll.
	if (v0 != descendant \|\| includeRootScroll) {
	pt[0] -= v0.getScrollX();
	pt[1] -= v0.getScrollY();
	}

	v0.getMatrix().mapPoints(pt);
	pt[0] += v0.getLeft();
	pt[1] += v0.getTop();
	scale *= v0.getScaleX();
	}

	coord[0] = (int) Math.round(pt[0]);
	coord[1] = (int) Math.round(pt[1]);
	return scale;
	}

	/**
	* Inverse of {@link #getDescendantCoordRelativeToSelf(View, int[])}.
	*/
	public static float mapCoordInSelfToDescendent(View descendant, View root,
	int[] coord) {
	ArrayList<View> ancestorChain = new ArrayList<View>();

	float[] pt = {coord[0], coord[1]};

	View v = descendant;
	while(v != root) {
	ancestorChain.add(v);
	v = (View) v.getParent();
	}
	ancestorChain.add(root);

	float scale = 1.0f;
	Matrix inverse = new Matrix();
	int count = ancestorChain.size();
	for (int i = count - 1; i >= 0; i--) {
	View ancestor = ancestorChain.get(i);
	View next = i > 0 ? ancestorChain.get(i-1) : null;

	pt[0] += ancestor.getScrollX();
	pt[1] += ancestor.getScrollY();

	if (next != null) {
	pt[0] -= next.getLeft();
	pt[1] -= next.getTop();
	next.getMatrix().invert(inverse);
	inverse.mapPoints(pt);
	scale *= next.getScaleX();
	}
	}

	coord[0] = (int) Math.round(pt[0]);
	coord[1] = (int) Math.round(pt[1]);
	return scale;
	}

	/**
	* Utility method to determine whether the given point, in local coordinates,
	* is inside the view, where the area of the view is expanded by the slop factor.
	* This method is called while processing touch-move events to determine if the event
	* is still within the view.
	*/
	public static boolean pointInView(View v, float localX, float localY, float slop) {
	return localX >= -slop && localY >= -slop && localX < (v.getWidth() + slop) &&
	localY < (v.getHeight() + slop);
	}

	private static void initStatics(Context context) {
	final Resources resources = context.getResources();
	sIconWidth = sIconHeight = (int) resources.getDimension(R.dimen.app_icon_size);
	sIconTextureWidth = sIconTextureHeight = sIconWidth;
	}

	public static void setIconSize(int widthPx) {
	sIconWidth = sIconHeight = widthPx;
	sIconTextureWidth = sIconTextureHeight = widthPx;
	}

	public static void scaleRect(Rect r, float scale) {
	if (scale != 1.0f) {
	r.left = (int) (r.left * scale + 0.5f);
	r.top = (int) (r.top * scale + 0.5f);
	r.right = (int) (r.right * scale + 0.5f);
	r.bottom = (int) (r.bottom * scale + 0.5f);
	}
	}

	public static int[] getCenterDeltaInScreenSpace(View v0, View v1, int[] delta) {
	v0.getLocationInWindow(sLoc0);
	v1.getLocationInWindow(sLoc1);

	sLoc0[0] += (v0.getMeasuredWidth() * v0.getScaleX()) / 2;
	sLoc0[1] += (v0.getMeasuredHeight() * v0.getScaleY()) / 2;
	sLoc1[0] += (v1.getMeasuredWidth() * v1.getScaleX()) / 2;
	sLoc1[1] += (v1.getMeasuredHeight() * v1.getScaleY()) / 2;

	if (delta == null) {
	delta = new int[2];
	}

	delta[0] = sLoc1[0] - sLoc0[0];
	delta[1] = sLoc1[1] - sLoc0[1];

	return delta;
	}

	public static void scaleRectAboutCenter(Rect r, float scale) {
	int cx = r.centerX();
	int cy = r.centerY();
	r.offset(-cx, -cy);
	Utilities.scaleRect(r, scale);
	r.offset(cx, cy);
	}

	public static void startActivityForResultSafely(
	Activity activity, Intent intent, int requestCode) {
	try {
	activity.startActivityForResult(intent, requestCode);
	} catch (ActivityNotFoundException e) {
	Toast.makeText(activity, R.string.activity_not_found, Toast.LENGTH_SHORT).show();
	} catch (SecurityException e) {
	Toast.makeText(activity, R.string.activity_not_found, Toast.LENGTH_SHORT).show();
	Log.e(TAG, "Launcher does not have the permission to launch " + intent +
	". Make sure to create a MAIN intent-filter for the corresponding activity " +
	"or use the exported attribute for this activity.", e);
	}
	}

	static boolean isSystemApp(Context context, Intent intent) {
	PackageManager pm = context.getPackageManager();
	ComponentName cn = intent.getComponent();
	String packageName = null;
	if (cn == null) {
	ResolveInfo info = pm.resolveActivity(intent, PackageManager.MATCH_DEFAULT_ONLY);
	if ((info != null) && (info.activityInfo != null)) {
	packageName = info.activityInfo.packageName;
	}
	} else {
	packageName = cn.getPackageName();
	}
	if (packageName != null) {
	try {
	PackageInfo info = pm.getPackageInfo(packageName, 0);
	return (info != null) && (info.applicationInfo != null) &&
	((info.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0);
	} catch (NameNotFoundException e) {
	return false;
	}
	} else {
	return false;
	}
	}

	/**
	* This picks a dominant color, looking for high-saturation, high-value, repeated hues.
	* @param bitmap The bitmap to scan
	* @param samples The approximate max number of samples to use.
	*/
	static int findDominantColorByHue(Bitmap bitmap, int samples) {
	final int height = bitmap.getHeight();
	final int width = bitmap.getWidth();
	int sampleStride = (int) Math.sqrt((height * width) / samples);
	if (sampleStride < 1) {
	sampleStride = 1;
	}

	// This is an out-param, for getting the hsv values for an rgb
	float[] hsv = new float[3];

	// First get the best hue, by creating a histogram over 360 hue buckets,
	// where each pixel contributes a score weighted by saturation, value, and alpha.
	float[] hueScoreHistogram = new float[360];
	float highScore = -1;
	int bestHue = -1;

	for (int y = 0; y < height; y += sampleStride) {
	for (int x = 0; x < width; x += sampleStride) {
	int argb = bitmap.getPixel(x, y);
	int alpha = 0xFF & (argb >> 24);
	if (alpha < 0x80) {
	// Drop mostly-transparent pixels.
	continue;
	}
	// Remove the alpha channel.
	int rgb = argb \| 0xFF000000;
	Color.colorToHSV(rgb, hsv);
	// Bucket colors by the 360 integer hues.
	int hue = (int) hsv[0];
	if (hue < 0 \|\| hue >= hueScoreHistogram.length) {
	// Defensively avoid array bounds violations.
	continue;
	}
	float score = hsv[1] * hsv[2];
	hueScoreHistogram[hue] += score;
	if (hueScoreHistogram[hue] > highScore) {
	highScore = hueScoreHistogram[hue];
	bestHue = hue;
	}
	}
	}

	SparseArray<Float> rgbScores = new SparseArray<Float>();
	int bestColor = 0xff000000;
	highScore = -1;
	// Go back over the RGB colors that match the winning hue,
	// creating a histogram of weighted sv scores, for up to 100100 [s,v] buckets.
	// The highest-scoring RGB color wins.
	for (int y = 0; y < height; y += sampleStride) {
	for (int x = 0; x < width; x += sampleStride) {
	int rgb = bitmap.getPixel(x, y) \| 0xff000000;
	Color.colorToHSV(rgb, hsv);
	int hue = (int) hsv[0];
	if (hue == bestHue) {
	float s = hsv[1];
	float v = hsv[2];
	int bucket = (int) (s * 100) + (int) (v * 10000);
	// Score by cumulative saturation * value.
	float score = s * v;
	Float oldTotal = rgbScores.get(bucket);
	float newTotal = oldTotal == null ? score : oldTotal + score;
	rgbScores.put(bucket, newTotal);
	if (newTotal > highScore) {
	highScore = newTotal;
	// All the colors in the winning bucket are very similar. Last in wins.
	bestColor = rgb;
	}
	}
	}
	}
	return bestColor;
	}

	/*
	* Finds a system apk which had a broadcast receiver listening to a particular action.
	* @param action intent action used to find the apk
	* @return a pair of apk package name and the resources.
	*/
	static Pair<String, Resources> findSystemApk(String action, PackageManager pm) {
	final Intent intent = new Intent(action);
	for (ResolveInfo info : pm.queryBroadcastReceivers(intent, 0)) {
	if (info.activityInfo != null &&
	(info.activityInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0) {
	final String packageName = info.activityInfo.packageName;
	try {
	final Resources res = pm.getResourcesForApplication(packageName);
	return Pair.create(packageName, res);
	} catch (NameNotFoundException e) {
	Log.w(TAG, "Failed to find resources for " + packageName);
	}
	}
	}
	return null;
	}
	}