1/*
2 * Copyright (C) 2011 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.server.wm;
18
19import android.graphics.Canvas;
20import android.graphics.Paint;
21import android.graphics.PixelFormat;
22import android.graphics.PorterDuff;
23import android.graphics.Rect;
24import android.graphics.Typeface;
25import android.graphics.Paint.FontMetricsInt;
26import android.util.DisplayMetrics;
27import android.util.Log;
28import android.util.TypedValue;
29import android.view.Display;
30import android.view.Surface;
31import android.view.SurfaceSession;
32import android.view.Surface.OutOfResourcesException;
33
34/**
35 * Displays a watermark on top of the window manager's windows.
36 */
37class Watermark {
38    final String[] mTokens;
39    final String mText;
40    final Paint mTextPaint;
41    final int mTextWidth;
42    final int mTextHeight;
43    final int mTextAscent;
44    final int mTextDescent;
45    final int mDeltaX;
46    final int mDeltaY;
47
48    Surface mSurface;
49    int mLastDW;
50    int mLastDH;
51    boolean mDrawNeeded;
52
53    Watermark(DisplayMetrics dm, SurfaceSession session, String[] tokens) {
54        if (false) {
55            Log.i(WindowManagerService.TAG, "*********************** WATERMARK");
56            for (int i=0; i<tokens.length; i++) {
57                Log.i(WindowManagerService.TAG, "  TOKEN #" + i + ": " + tokens[i]);
58            }
59        }
60
61        mTokens = tokens;
62
63        StringBuilder builder = new StringBuilder(32);
64        int len = mTokens[0].length();
65        len = len & ~1;
66        for (int i=0; i<len; i+=2) {
67            int c1 = mTokens[0].charAt(i);
68            int c2 = mTokens[0].charAt(i+1);
69            if (c1 >= 'a' && c1 <= 'f') c1 = c1 - 'a' + 10;
70            else if (c1 >= 'A' && c1 <= 'F') c1 = c1 - 'A' + 10;
71            else c1 -= '0';
72            if (c2 >= 'a' && c2 <= 'f') c2 = c2 - 'a' + 10;
73            else if (c2 >= 'A' && c2 <= 'F') c2 = c2 - 'A' + 10;
74            else c2 -= '0';
75            builder.append((char)(255-((c1*16)+c2)));
76        }
77        mText = builder.toString();
78        if (false) {
79            Log.i(WindowManagerService.TAG, "Final text: " + mText);
80        }
81
82        int fontSize = WindowManagerService.getPropertyInt(tokens, 1,
83                TypedValue.COMPLEX_UNIT_DIP, 20, dm);
84
85        mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
86        mTextPaint.setTextSize(fontSize);
87        mTextPaint.setTypeface(Typeface.create(Typeface.SANS_SERIF, Typeface.BOLD));
88
89        FontMetricsInt fm = mTextPaint.getFontMetricsInt();
90        mTextWidth = (int)mTextPaint.measureText(mText);
91        mTextAscent = fm.ascent;
92        mTextDescent = fm.descent;
93        mTextHeight = fm.descent - fm.ascent;
94
95        mDeltaX = WindowManagerService.getPropertyInt(tokens, 2,
96                TypedValue.COMPLEX_UNIT_PX, mTextWidth*2, dm);
97        mDeltaY = WindowManagerService.getPropertyInt(tokens, 3,
98                TypedValue.COMPLEX_UNIT_PX, mTextHeight*3, dm);
99        int shadowColor = WindowManagerService.getPropertyInt(tokens, 4,
100                TypedValue.COMPLEX_UNIT_PX, 0xb0000000, dm);
101        int color = WindowManagerService.getPropertyInt(tokens, 5,
102                TypedValue.COMPLEX_UNIT_PX, 0x60ffffff, dm);
103        int shadowRadius = WindowManagerService.getPropertyInt(tokens, 6,
104                TypedValue.COMPLEX_UNIT_PX, 7, dm);
105        int shadowDx = WindowManagerService.getPropertyInt(tokens, 8,
106                TypedValue.COMPLEX_UNIT_PX, 0, dm);
107        int shadowDy = WindowManagerService.getPropertyInt(tokens, 9,
108                TypedValue.COMPLEX_UNIT_PX, 0, dm);
109
110        mTextPaint.setColor(color);
111        mTextPaint.setShadowLayer(shadowRadius, shadowDx, shadowDy, shadowColor);
112
113        try {
114            mSurface = new Surface(session, 0,
115                    "WatermarkSurface", -1, 1, 1, PixelFormat.TRANSLUCENT, 0);
116            mSurface.setLayer(WindowManagerService.TYPE_LAYER_MULTIPLIER*100);
117            mSurface.setPosition(0, 0);
118            mSurface.show();
119        } catch (OutOfResourcesException e) {
120        }
121    }
122
123    void positionSurface(int dw, int dh) {
124        if (mLastDW != dw || mLastDH != dh) {
125            mLastDW = dw;
126            mLastDH = dh;
127            mSurface.setSize(dw, dh);
128            mDrawNeeded = true;
129        }
130    }
131
132    void drawIfNeeded() {
133        if (mDrawNeeded) {
134            final int dw = mLastDW;
135            final int dh = mLastDH;
136
137            mDrawNeeded = false;
138            Rect dirty = new Rect(0, 0, dw, dh);
139            Canvas c = null;
140            try {
141                c = mSurface.lockCanvas(dirty);
142            } catch (IllegalArgumentException e) {
143            } catch (OutOfResourcesException e) {
144            }
145            if (c != null) {
146                c.drawColor(0, PorterDuff.Mode.CLEAR);
147
148                int deltaX = mDeltaX;
149                int deltaY = mDeltaY;
150
151                // deltaX shouldn't be close to a round fraction of our
152                // x step, or else things will line up too much.
153                int div = (dw+mTextWidth)/deltaX;
154                int rem = (dw+mTextWidth) - (div*deltaX);
155                int qdelta = deltaX/4;
156                if (rem < qdelta || rem > (deltaX-qdelta)) {
157                    deltaX += deltaX/3;
158                }
159
160                int y = -mTextHeight;
161                int x = -mTextWidth;
162                while (y < (dh+mTextHeight)) {
163                    c.drawText(mText, x, y, mTextPaint);
164                    x += deltaX;
165                    if (x >= dw) {
166                        x -= (dw+mTextWidth);
167                        y += deltaY;
168                    }
169                }
170                mSurface.unlockCanvasAndPost(c);
171            }
172        }
173    }
174}