LetterTileProvider.java revision bd390369b0b4e503463b92a0bbffdbaf5c7d0b9a 
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
17package com.android.mail.photomanager;
18
19import android.content.res.Resources;
20import android.content.res.TypedArray;
21import android.graphics.Bitmap;
22import android.graphics.BitmapFactory;
23import android.graphics.Canvas;
24import android.graphics.Paint.Align;
25import android.graphics.Rect;
26import android.graphics.Typeface;
27import android.text.TextPaint;
28import android.text.TextUtils;
29
30import com.android.mail.R;
31import com.android.mail.photomanager.ContactPhotoManager.ContactIdentifier;
32import com.android.mail.photomanager.PhotoManager.DefaultImageProvider;
33import com.android.mail.photomanager.PhotoManager.PhotoIdentifier;
34import com.android.mail.ui.DividedImageCanvas;
35import com.android.mail.ui.ImageCanvas;
36import com.android.mail.utils.LogTag;
37import com.android.mail.utils.LogUtils;
38
39import java.util.regex.Matcher;
40import java.util.regex.Pattern;
41
42/**
43 * LetterTileProvider is an implementation of the DefaultImageProvider. When no
44 * matching contact photo is found, and there is a supplied displayName or email
45 * address whose first letter corresponds to an English alphabet letter (or
46 * number), this method creates a bitmap with the letter in the center of a
47 * tile. If there is no English alphabet character (or digit), it creates a
48 * bitmap with the default contact avatar.
49 */
50public class LetterTileProvider implements DefaultImageProvider {
51    private static final String TAG = LogTag.getLogTag();
52    private Bitmap mDefaultBitmap;
53    private static Bitmap[] sBitmapBackgroundCache;
54    private static Typeface sSansSerifLight;
55    private static Rect sBounds;
56    private static int sTileLetterFontSize = -1;
57    private static int sTileLetterFontSizeSmall;
58    private static int sTileFontColor;
59    private static TextPaint sPaint = new TextPaint();
60    private static int DEFAULT_AVATAR_DRAWABLE = R.drawable.ic_contact_picture;
61    private static final Pattern ALPHABET = Pattern.compile("^[a-zA-Z0-9]+$");
62    private static final int POSSIBLE_BITMAP_SIZES = 3;
63
64    // This should match the total number of colors defined in colors.xml for letter_tile_color
65    private static final int NUM_OF_TILE_COLORS = 8;
66
67    public LetterTileProvider() {
68        super();
69    }
70
71    @Override
72    public void applyDefaultImage(PhotoIdentifier id, ImageCanvas view, int extent) {
73        ContactIdentifier contactIdentifier = (ContactIdentifier) id;
74        DividedImageCanvas dividedImageView = (DividedImageCanvas) view;
75
76        String displayName = contactIdentifier.name;
77        String address = contactIdentifier.emailAddress;
78
79        Bitmap bitmap = null;
80        final String display = !TextUtils.isEmpty(displayName) ? displayName : address;
81        final String firstChar = display.substring(0, 1);
82        // If its a valid english alphabet letter...
83        if (isLetter(firstChar)) {
84            final Resources res = dividedImageView.getContext().getResources();
85            if (sTileLetterFontSize == -1) {
86                sTileLetterFontSize = res.getDimensionPixelSize(R.dimen.tile_letter_font_size);
87                sTileLetterFontSizeSmall = res
88                        .getDimensionPixelSize(R.dimen.tile_letter_font_size_small);
89                sTileFontColor = res.getColor(R.color.letter_tile_font_color);
90                sSansSerifLight = Typeface.create("sans-serif-light", Typeface.NORMAL);
91                sBounds = new Rect();
92                sPaint.setTypeface(sSansSerifLight);
93                sPaint.setColor(sTileFontColor);
94                sPaint.setTextAlign(Align.CENTER);
95                sPaint.setAntiAlias(true);
96                sBitmapBackgroundCache = new Bitmap[POSSIBLE_BITMAP_SIZES];
97            }
98            final String first = firstChar.toUpperCase();
99            DividedImageCanvas.Dimensions d = dividedImageView.getDesiredDimensions(address);
100            bitmap = getBitmap(d);
101            if (bitmap == null) {
102                LogUtils.w(TAG,
103                        "LetterTileProvider width(%d) or height(%d) is 0 for name %s and address %s.",
104                        dividedImageView.getWidth(), dividedImageView.getHeight(), displayName,
105                        address);
106                return;
107            }
108            Canvas c = new Canvas(bitmap);
109            c.drawColor(pickColor(res, address));
110            sPaint.setTextSize(getFontSize(d.scale));
111            sPaint.getTextBounds(first, 0, first.length(), sBounds);
112            c.drawText(first, 0 + d.width / 2, 0 + d.height / 2 + (sBounds.bottom - sBounds.top)
113                    / 2, sPaint);
114        } else {
115            if (mDefaultBitmap == null) {
116                BitmapFactory.Options options = new BitmapFactory.Options();
117                options.inMutable = true;
118                mDefaultBitmap = BitmapFactory.decodeResource(dividedImageView.getContext().getResources(),
119                        DEFAULT_AVATAR_DRAWABLE, options);
120            }
121            bitmap = mDefaultBitmap;
122        }
123        dividedImageView.addDivisionImage(bitmap, address);
124    }
125
126    private static Bitmap getBitmap(final DividedImageCanvas.Dimensions d) {
127        if (d.width <= 0 || d.height <= 0) {
128            LogUtils.w(TAG,
129                    "LetterTileProvider width(%d) or height(%d) is 0.", d.width, d.height);
130            return null;
131        }
132        final int pos;
133        float scale = d.scale;
134        if (scale == DividedImageCanvas.ONE) {
135            pos = 0;
136        } else if (scale == DividedImageCanvas.HALF) {
137            pos = 1;
138        } else {
139            pos = 2;
140        }
141        Bitmap bitmap = sBitmapBackgroundCache[pos];
142        if (bitmap == null) {
143            // create and place the bitmap
144            bitmap = Bitmap.createBitmap(d.width, d.height, Bitmap.Config.ARGB_8888);
145            sBitmapBackgroundCache[pos] = bitmap;
146        }
147        return bitmap;
148    }
149
150    private static int getFontSize(float scale)  {
151        if (scale == DividedImageCanvas.ONE) {
152            return sTileLetterFontSize;
153        } else {
154            return sTileLetterFontSizeSmall;
155        }
156    }
157
158    private static boolean isLetter(String letter) {
159        Matcher m = ALPHABET.matcher(letter);
160        return m.matches();
161    }
162
163    private static int pickColor(Resources res, String emailAddress) {
164        // String.hashCode() implementation is not supposed to change across java versions, so
165        // this should guarantee the same email address always maps to the same color.
166        int color = Math.abs(emailAddress.hashCode()) % NUM_OF_TILE_COLORS;
167        TypedArray colors = res.obtainTypedArray(R.array.letter_tile_colors);
168        return colors.getColor(color, R.color.letter_tile_default_color);
169    }
170}
171