The Tor Browser: mobile/android/base/LightweightTheme.java@b8a032363ba2 (annotated)

mobile/android/base/LightweightTheme.java@b8a032363ba2 (annotated)

mobile/android/base/LightweightTheme.java

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 package org.mozilla.gecko;
 import org.mozilla.gecko.gfx.BitmapUtils;
 import org.mozilla.gecko.util.GeckoEventListener;
 import org.mozilla.gecko.util.ThreadUtils;
 import org.json.JSONObject;
 import android.app.Application;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Rect;
 import android.graphics.Shader;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
 import android.os.Handler;
 import android.os.Looper;
 import android.util.DisplayMetrics;
 import android.util.Log;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewParent;
 import java.util.ArrayList;
 import java.util.List;
 public class LightweightTheme implements GeckoEventListener {
     private static final String LOGTAG = "GeckoLightweightTheme";
     private Application mApplication;
     private Handler mHandler;
     private Bitmap mBitmap;
     private int mColor;
     private boolean mIsLight;
     public static interface OnChangeListener {
         // The View should change its background/text color.
         public void onLightweightThemeChanged();
         // The View should reset to its default background/text color.
         public void onLightweightThemeReset();
     }
     private List<OnChangeListener> mListeners;
     public LightweightTheme(Application application) {
         mApplication = application;
         mHandler = new Handler(Looper.getMainLooper());
         mListeners = new ArrayList<OnChangeListener>();
         // unregister isn't needed as the lifetime is same as the application.
         GeckoAppShell.getEventDispatcher().registerEventListener("LightweightTheme:Update", this);
         GeckoAppShell.getEventDispatcher().registerEventListener("LightweightTheme:Disable", this);
     }
     public void addListener(final OnChangeListener listener) {
         // Don't inform the listeners that attached late.
         // Their onLayout() will take care of them before their onDraw();
         mListeners.add(listener);
     }
     public void removeListener(OnChangeListener listener) {
         mListeners.remove(listener);
     }
     @Override
     public void handleMessage(String event, JSONObject message) {
         try {
             if (event.equals("LightweightTheme:Update")) {
                 JSONObject lightweightTheme = message.getJSONObject("data");
                 final String headerURL = lightweightTheme.getString("headerURL");
                 // Move any heavy lifting off the Gecko thread
                 ThreadUtils.postToBackgroundThread(new Runnable() {
                     @Override
                     public void run() {
                         String croppedURL = headerURL;
                         int mark = croppedURL.indexOf('?');
                         if (mark != -1)
                             croppedURL = croppedURL.substring(0, mark);
                         // Get the image and convert it to a bitmap.
                         final Bitmap bitmap = BitmapUtils.decodeUrl(croppedURL);
                         mHandler.post(new Runnable() {
                             @Override
                             public void run() {
                                 setLightweightTheme(bitmap);
                             }
                         });
                     }
                 });
             } else if (event.equals("LightweightTheme:Disable")) {
                 mHandler.post(new Runnable() {
                     @Override
                     public void run() {
                         resetLightweightTheme();
                     }
                 });
             }
         } catch (Exception e) {
             Log.e(LOGTAG, "Exception handling message \"" + event + "\":", e);
         }
     }
     /**
      * Set a new lightweight theme with the given bitmap.
      * Note: This should be called on the UI thread to restrict accessing the
      * bitmap to a single thread.
      *
      * @param bitmap The bitmap used for the lightweight theme.
      */
     private void setLightweightTheme(Bitmap bitmap) {
         if (bitmap == null || bitmap.getWidth() == 0 || bitmap.getHeight() == 0) {
             mBitmap = null;
             return;
         }
         // To find the dominant color only once, take the bottom 25% of pixels.
         DisplayMetrics dm = mApplication.getResources().getDisplayMetrics();
         int maxWidth = Math.max(dm.widthPixels, dm.heightPixels);
         int height = (int) (bitmap.getHeight() * 0.25);
         // The lightweight theme image's width and height.
         int bitmapWidth = bitmap.getWidth();
         int bitmapHeight = bitmap.getHeight();
         // A cropped bitmap of the bottom 25% of pixels.
         Bitmap cropped = Bitmap.createBitmap(bitmap,
                                              bitmapWidth > maxWidth ? bitmapWidth - maxWidth : 0,
                                              bitmapHeight - height,
                                              bitmapWidth > maxWidth ? maxWidth : bitmapWidth,
                                              height);
         // Dominant color based on the cropped bitmap.
         mColor = BitmapUtils.getDominantColor(cropped, false);
         // Calculate the luminance to determine if it's a light or a dark theme.
         double luminance = (0.2125 * ((mColor & 0x00FF0000) >> 16)) +
                            (0.7154 * ((mColor & 0x0000FF00) >> 8)) +
                            (0.0721 * (mColor &0x000000FF));
         mIsLight = (luminance > 110) ? true : false;
         // The bitmap image might be smaller than the device's width.
         // If it's smaller, fill the extra space on the left with the dominant color.
         if (bitmap.getWidth() >= maxWidth) {
             mBitmap = bitmap;
         } else {
             Paint paint = new Paint();
             paint.setAntiAlias(true);
             // Create a bigger image that can fill the device width.
             // By creating a canvas for the bitmap, anything drawn on the canvas
             // will be drawn on the bitmap.
             mBitmap = Bitmap.createBitmap(maxWidth, bitmapHeight, Bitmap.Config.ARGB_8888);
             Canvas canvas = new Canvas(mBitmap);
             // Fill the canvas with dominant color.
             canvas.drawColor(mColor);
             // The image should be top-right aligned.
             Rect rect = new Rect();
             Gravity.apply(Gravity.TOP | Gravity.RIGHT,
                           bitmapWidth,
                           bitmapHeight,
                           new Rect(0, 0, maxWidth, bitmapHeight),
                           rect);
             // Draw the bitmap.
             canvas.drawBitmap(bitmap, null, rect, paint);
         }
         for (OnChangeListener listener : mListeners)
             listener.onLightweightThemeChanged();
     }
     /**
      * Reset the lightweight theme.
      * Note: This should be called on the UI thread to restrict accessing the
      * bitmap to a single thread.
      */
     private void resetLightweightTheme() {
         if (mBitmap != null) {
             // Reset the bitmap.
             mBitmap = null;
             for (OnChangeListener listener : mListeners)
                 listener.onLightweightThemeReset();
         }
     }
     /**
      * A lightweight theme is enabled only if there is an active bitmap.
      *
      * @return True if the theme is enabled.
      */
     public boolean isEnabled() {
         return (mBitmap != null);
     }
     /**
      * Based on the luminance of the domanint color, a theme is classified as light or dark.
      *
      * @return True if the theme is light.
      */
     public boolean isLightTheme() {
         return mIsLight;
     }
     /**
      * Crop the image based on the position of the view on the window.
      * Either the View or one of its ancestors might have scrolled or translated.
      * This value should be taken into account while mapping the View to the Bitmap.
      *
      * @param view The view requesting a cropped bitmap.
      */
     private Bitmap getCroppedBitmap(View view) {
         if (mBitmap == null || view == null)
             return null;
         // Get the global position of the view on the entire screen.
         Rect rect = new Rect();
         view.getGlobalVisibleRect(rect);
         // Get the activity's window position. This does an IPC call, may be expensive.
         Rect window = new Rect();
         view.getWindowVisibleDisplayFrame(window);
         // Calculate the coordinates for the cropped bitmap.
         int screenWidth = view.getContext().getResources().getDisplayMetrics().widthPixels;
         int left = mBitmap.getWidth() - screenWidth + rect.left;
         int right = mBitmap.getWidth() - screenWidth + rect.right;
         int top = rect.top - window.top;
         int bottom = rect.bottom - window.top;
         int offsetX = 0;
         int offsetY = 0;
         // Find if this view or any of its ancestors has been translated or scrolled.
         ViewParent parent;
         View curView = view;
         do {
             if (Build.VERSION.SDK_INT >= 11) {
                 offsetX += (int) curView.getTranslationX() - curView.getScrollX();
                 offsetY += (int) curView.getTranslationY() - curView.getScrollY();
             } else {
                 offsetX -= curView.getScrollX();
                 offsetY -= curView.getScrollY();
             }
             parent = curView.getParent();
             if (parent instanceof View)
                 curView = (View) parent;
         } while(parent instanceof View && parent != null);
         // Adjust the coordinates for the offset.
         left -= offsetX;
         right -= offsetX;
         top -= offsetY;
         bottom -= offsetY;
         // The either the required height may be less than the available image height or more than it.
         // If the height required is more, crop only the available portion on the image.
         int width = right - left;
         int height = (bottom > mBitmap.getHeight() ? mBitmap.getHeight() - top : bottom - top);
         // There is a chance that the view is not visible or doesn't fall within the phone's size.
         // In this case, 'rect' will have all values as '0'. Hence 'top' and 'bottom' may be negative,
         // and createBitmap() will fail.
         // The view will get a background in its next layout pass.
         try {
             return Bitmap.createBitmap(mBitmap, left, top, width, height);
         } catch (Exception e) {
             return null;
         }
     }
     /**
      * Converts the cropped bitmap to a BitmapDrawable and returns the same.
      *
      * @param view The view for which a background drawable is required.
      * @return Either the cropped bitmap as a Drawable or null.
      */
     public Drawable getDrawable(View view) {
         Bitmap bitmap = getCroppedBitmap(view);
         if (bitmap == null)
             return null;
         BitmapDrawable drawable = new BitmapDrawable(view.getContext().getResources(), bitmap);
         drawable.setGravity(Gravity.TOP|Gravity.RIGHT);
         drawable.setTileModeXY(Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
         return drawable;
     }
     /**
      * Converts the cropped bitmap to a LightweightThemeDrawable, placing it over the dominant color.
      *
      * @param view The view for which a background drawable is required.
      * @return Either the cropped bitmap as a Drawable or null.
      */
      public LightweightThemeDrawable getColorDrawable(View view) {
          return getColorDrawable(view, mColor, false);
      }
     /**
      * Converts the cropped bitmap to a LightweightThemeDrawable, placing it over the required color.
      *
      * @param view The view for which a background drawable is required.
      * @param color The color over which the drawable should be drawn.
      * @return Either the cropped bitmap as a Drawable or null.
      */
     public LightweightThemeDrawable getColorDrawable(View view, int color) {
         return getColorDrawable(view, color, false);
     }
     /**
      * Converts the cropped bitmap to a LightweightThemeDrawable, placing it over the required color.
      *
      * @param view The view for which a background drawable is required.
      * @param color The color over which the drawable should be drawn.
      * @param needsDominantColor A layer of dominant color is needed or not.
      * @return Either the cropped bitmap as a Drawable or null.
      */
     public LightweightThemeDrawable getColorDrawable(View view, int color, boolean needsDominantColor) {
         Bitmap bitmap = getCroppedBitmap(view);
         if (bitmap == null)
             return null;
         LightweightThemeDrawable drawable = new LightweightThemeDrawable(view.getContext().getResources(), bitmap);
         if (needsDominantColor)
             drawable.setColorWithFilter(color, (mColor & 0x22FFFFFF));
         else
             drawable.setColor(color);
         return drawable;
     }
 }

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mobile/android/base/LightweightTheme.java@b8a032363ba2 (annotated)

mobile/android/base/LightweightTheme.java