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.OutOfResourcesException;
31import android.view.Surface;
32import android.view.SurfaceControl;
33import android.view.SurfaceSession;
34
35/**
36 * Displays a watermark on top of the window manager's windows.
37 */
38class Watermark {
39    private final Display mDisplay;
40    private final String[] mTokens;
41    private final String mText;
42    private final Paint mTextPaint;
43    private final int mTextWidth;
44    private final int mTextHeight;
45    private final int mDeltaX;
46    private final int mDeltaY;
47
48    private final SurfaceControl mSurfaceControl;
49    private final Surface mSurface = new Surface();
50    private int mLastDW;
51    private int mLastDH;
52    private boolean mDrawNeeded;
53
54    Watermark(Display display, DisplayMetrics dm, SurfaceSession session, String[] tokens) {
55        if (false) {
56            Log.i(WindowManagerService.TAG, "*********************** WATERMARK");
57            for (int i=0; i<tokens.length; i++) {
58                Log.i(WindowManagerService.TAG, "  TOKEN #" + i + ": " + tokens[i]);
59            }
60        }
61
62        mDisplay = display;
63        mTokens = tokens;
64
65        StringBuilder builder = new StringBuilder(32);
66        int len = mTokens[0].length();
67        len = len & ~1;
68        for (int i=0; i<len; i+=2) {
69            int c1 = mTokens[0].charAt(i);
70            int c2 = mTokens[0].charAt(i+1);
71            if (c1 >= 'a' && c1 <= 'f') c1 = c1 - 'a' + 10;
72            else if (c1 >= 'A' && c1 <= 'F') c1 = c1 - 'A' + 10;
73            else c1 -= '0';
74            if (c2 >= 'a' && c2 <= 'f') c2 = c2 - 'a' + 10;
75            else if (c2 >= 'A' && c2 <= 'F') c2 = c2 - 'A' + 10;
76            else c2 -= '0';
77            builder.append((char)(255-((c1*16)+c2)));
78        }
79        mText = builder.toString();
80        if (false) {
81            Log.i(WindowManagerService.TAG, "Final text: " + mText);
82        }
83
84        int fontSize = WindowManagerService.getPropertyInt(tokens, 1,
85                TypedValue.COMPLEX_UNIT_DIP, 20, dm);
86
87        mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
88        mTextPaint.setTextSize(fontSize);
89        mTextPaint.setTypeface(Typeface.create(Typeface.SANS_SERIF, Typeface.BOLD));
90
91        FontMetricsInt fm = mTextPaint.getFontMetricsInt();
92        mTextWidth = (int)mTextPaint.measureText(mText);
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        SurfaceControl ctrl = null;
114        try {
115            ctrl = new SurfaceControl(session, "WatermarkSurface",
116                    1, 1, PixelFormat.TRANSLUCENT, SurfaceControl.HIDDEN);
117            ctrl.setLayerStack(mDisplay.getLayerStack());
118            ctrl.setLayer(WindowManagerService.TYPE_LAYER_MULTIPLIER*100);
119            ctrl.setPosition(0, 0);
120            ctrl.show();
121            mSurface.copyFrom(ctrl);
122        } catch (OutOfResourcesException e) {
123        }
124        mSurfaceControl = ctrl;
125    }
126
127    void positionSurface(int dw, int dh) {
128        if (mLastDW != dw || mLastDH != dh) {
129            mLastDW = dw;
130            mLastDH = dh;
131            mSurfaceControl.setSize(dw, dh);
132            mDrawNeeded = true;
133        }
134    }
135
136    void drawIfNeeded() {
137        if (mDrawNeeded) {
138            final int dw = mLastDW;
139            final int dh = mLastDH;
140
141            mDrawNeeded = false;
142            Rect dirty = new Rect(0, 0, dw, dh);
143            Canvas c = null;
144            try {
145                c = mSurface.lockCanvas(dirty);
146            } catch (IllegalArgumentException e) {
147            } catch (Surface.OutOfResourcesException e) {
148            }
149            if (c != null) {
150                c.drawColor(0, PorterDuff.Mode.CLEAR);
151
152                int deltaX = mDeltaX;
153                int deltaY = mDeltaY;
154
155                // deltaX shouldn't be close to a round fraction of our
156                // x step, or else things will line up too much.
157                int div = (dw+mTextWidth)/deltaX;
158                int rem = (dw+mTextWidth) - (div*deltaX);
159                int qdelta = deltaX/4;
160                if (rem < qdelta || rem > (deltaX-qdelta)) {
161                    deltaX += deltaX/3;
162                }
163
164                int y = -mTextHeight;
165                int x = -mTextWidth;
166                while (y < (dh+mTextHeight)) {
167                    c.drawText(mText, x, y, mTextPaint);
168                    x += deltaX;
169                    if (x >= dw) {
170                        x -= (dw+mTextWidth);
171                        y += deltaY;
172                    }
173                }
174                mSurface.unlockCanvasAndPost(c);
175            }
176        }
177    }
178}
179