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      1 /*
      2  * Copyright (C) 2013 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.gallery3d.filtershow.tools;
     18 
     19 import android.graphics.Bitmap;
     20 import android.graphics.Canvas;
     21 import android.graphics.Paint;
     22 import android.graphics.Rect;
     23 import android.graphics.RectF;
     24 
     25 /**
     26  * A factory class for producing bitmaps to use as UI icons.
     27  */
     28 public class IconFactory {
     29 
     30     /**
     31      * Builds an icon with the dimensions iconWidth:iconHeight. If scale is set
     32      * the source image is stretched to fit within the given dimensions;
     33      * otherwise, the source image is cropped to the proper aspect ratio.
     34      *
     35      * @param sourceImage image to create an icon from.
     36      * @param iconWidth width of the icon bitmap.
     37      * @param iconHeight height of the icon bitmap.
     38      * @param scale if true, stretch sourceImage to fit the icon dimensions.
     39      * @return an icon bitmap with the dimensions iconWidth:iconHeight.
     40      */
     41     public static Bitmap createIcon(Bitmap sourceImage, int iconWidth, int iconHeight,
     42             boolean scale) {
     43         if (sourceImage == null) {
     44             throw new IllegalArgumentException("Null argument to buildIcon");
     45         }
     46 
     47         int sourceWidth = sourceImage.getWidth();
     48         int sourceHeight = sourceImage.getHeight();
     49 
     50         if (sourceWidth == 0 || sourceHeight == 0 || iconWidth == 0 || iconHeight == 0) {
     51             throw new IllegalArgumentException("Bitmap with dimension 0 used as input");
     52         }
     53 
     54         Bitmap icon = Bitmap.createBitmap(iconWidth, iconHeight,
     55                 Bitmap.Config.ARGB_8888);
     56         drawIcon(icon, sourceImage, scale);
     57         return icon;
     58     }
     59 
     60     /**
     61      * Draws an icon in the destination bitmap. If scale is set the source image
     62      * is stretched to fit within the destination dimensions; otherwise, the
     63      * source image is cropped to the proper aspect ratio.
     64      *
     65      * @param dest bitmap into which to draw the icon.
     66      * @param sourceImage image to create an icon from.
     67      * @param scale if true, stretch sourceImage to fit the destination.
     68      */
     69     public static void drawIcon(Bitmap dest, Bitmap sourceImage, boolean scale) {
     70         if (dest == null || sourceImage == null) {
     71             throw new IllegalArgumentException("Null argument to buildIcon");
     72         }
     73 
     74         int sourceWidth = sourceImage.getWidth();
     75         int sourceHeight = sourceImage.getHeight();
     76         int iconWidth = dest.getWidth();
     77         int iconHeight = dest.getHeight();
     78 
     79         if (sourceWidth == 0 || sourceHeight == 0 || iconWidth == 0 || iconHeight == 0) {
     80             throw new IllegalArgumentException("Bitmap with dimension 0 used as input");
     81         }
     82 
     83         Rect destRect = new Rect(0, 0, iconWidth, iconHeight);
     84         Canvas canvas = new Canvas(dest);
     85 
     86         Rect srcRect = null;
     87         if (scale) {
     88             // scale image to fit in icon (stretches if aspect isn't the same)
     89             srcRect = new Rect(0, 0, sourceWidth, sourceHeight);
     90         } else {
     91             // crop image to aspect ratio iconWidth:iconHeight
     92             float wScale = sourceWidth / (float) iconWidth;
     93             float hScale = sourceHeight / (float) iconHeight;
     94             float s = Math.min(hScale, wScale);
     95 
     96             float iw = iconWidth * s;
     97             float ih = iconHeight * s;
     98 
     99             float borderW = (sourceWidth - iw) / 2.0f;
    100             float borderH = (sourceHeight - ih) / 2.0f;
    101             RectF rec = new RectF(borderW, borderH, borderW + iw, borderH + ih);
    102             srcRect = new Rect();
    103             rec.roundOut(srcRect);
    104         }
    105 
    106         canvas.drawBitmap(sourceImage, srcRect, destRect, new Paint(Paint.FILTER_BITMAP_FLAG));
    107     }
    108 }
    109