1/*
2 * Copyright (C) 2009 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.example.android.livecubes.cube1;
18
19import android.graphics.Canvas;
20import android.graphics.Paint;
21import android.graphics.Rect;
22import android.os.Handler;
23import android.os.SystemClock;
24import android.service.wallpaper.WallpaperService;
25import android.util.Log;
26import android.view.MotionEvent;
27import android.view.SurfaceHolder;
28
29/*
30 * This animated wallpaper draws a rotating wireframe cube.
31 */
32public class CubeWallpaper1 extends WallpaperService {
33
34    private final Handler mHandler = new Handler();
35
36    @Override
37    public void onCreate() {
38        super.onCreate();
39    }
40
41    @Override
42    public void onDestroy() {
43        super.onDestroy();
44    }
45
46    @Override
47    public Engine onCreateEngine() {
48        return new CubeEngine();
49    }
50
51    class CubeEngine extends Engine {
52
53        private final Paint mPaint = new Paint();
54        private float mOffset;
55        private float mTouchX = -1;
56        private float mTouchY = -1;
57        private long mStartTime;
58        private float mCenterX;
59        private float mCenterY;
60
61        private final Runnable mDrawCube = new Runnable() {
62            public void run() {
63                drawFrame();
64            }
65        };
66        private boolean mVisible;
67
68        CubeEngine() {
69            // Create a Paint to draw the lines for our cube
70            final Paint paint = mPaint;
71            paint.setColor(0xffffffff);
72            paint.setAntiAlias(true);
73            paint.setStrokeWidth(2);
74            paint.setStrokeCap(Paint.Cap.ROUND);
75            paint.setStyle(Paint.Style.STROKE);
76
77            mStartTime = SystemClock.elapsedRealtime();
78        }
79
80        @Override
81        public void onCreate(SurfaceHolder surfaceHolder) {
82            super.onCreate(surfaceHolder);
83
84            // By default we don't get touch events, so enable them.
85            setTouchEventsEnabled(true);
86        }
87
88        @Override
89        public void onDestroy() {
90            super.onDestroy();
91            mHandler.removeCallbacks(mDrawCube);
92        }
93
94        @Override
95        public void onVisibilityChanged(boolean visible) {
96            mVisible = visible;
97            if (visible) {
98                drawFrame();
99            } else {
100                mHandler.removeCallbacks(mDrawCube);
101            }
102        }
103
104        @Override
105        public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
106            super.onSurfaceChanged(holder, format, width, height);
107            // store the center of the surface, so we can draw the cube in the right spot
108            mCenterX = width/2.0f;
109            mCenterY = height/2.0f;
110            drawFrame();
111        }
112
113        @Override
114        public void onSurfaceCreated(SurfaceHolder holder) {
115            super.onSurfaceCreated(holder);
116        }
117
118        @Override
119        public void onSurfaceDestroyed(SurfaceHolder holder) {
120            super.onSurfaceDestroyed(holder);
121            mVisible = false;
122            mHandler.removeCallbacks(mDrawCube);
123        }
124
125        @Override
126        public void onOffsetsChanged(float xOffset, float yOffset,
127                float xStep, float yStep, int xPixels, int yPixels) {
128            mOffset = xOffset;
129            drawFrame();
130        }
131
132        /*
133         * Store the position of the touch event so we can use it for drawing later
134         */
135        @Override
136        public void onTouchEvent(MotionEvent event) {
137            if (event.getAction() == MotionEvent.ACTION_MOVE) {
138                mTouchX = event.getX();
139                mTouchY = event.getY();
140            } else {
141                mTouchX = -1;
142                mTouchY = -1;
143            }
144            super.onTouchEvent(event);
145        }
146
147        /*
148         * Draw one frame of the animation. This method gets called repeatedly
149         * by posting a delayed Runnable. You can do any drawing you want in
150         * here. This example draws a wireframe cube.
151         */
152        void drawFrame() {
153            final SurfaceHolder holder = getSurfaceHolder();
154
155            Canvas c = null;
156            try {
157                c = holder.lockCanvas();
158                if (c != null) {
159                    // draw something
160                    drawCube(c);
161                    drawTouchPoint(c);
162                }
163            } finally {
164                if (c != null) holder.unlockCanvasAndPost(c);
165            }
166
167            // Reschedule the next redraw
168            mHandler.removeCallbacks(mDrawCube);
169            if (mVisible) {
170                mHandler.postDelayed(mDrawCube, 1000 / 25);
171            }
172        }
173
174        /*
175         * Draw a wireframe cube by drawing 12 3 dimensional lines between
176         * adjacent corners of the cube
177         */
178        void drawCube(Canvas c) {
179            c.save();
180            c.translate(mCenterX, mCenterY);
181            c.drawColor(0xff000000);
182            drawLine(c, -400, -400, -400,  400, -400, -400);
183            drawLine(c,  400, -400, -400,  400,  400, -400);
184            drawLine(c,  400,  400, -400, -400,  400, -400);
185            drawLine(c, -400,  400, -400, -400, -400, -400);
186
187            drawLine(c, -400, -400,  400,  400, -400,  400);
188            drawLine(c,  400, -400,  400,  400,  400,  400);
189            drawLine(c,  400,  400,  400, -400,  400,  400);
190            drawLine(c, -400,  400,  400, -400, -400,  400);
191
192            drawLine(c, -400, -400,  400, -400, -400, -400);
193            drawLine(c,  400, -400,  400,  400, -400, -400);
194            drawLine(c,  400,  400,  400,  400,  400, -400);
195            drawLine(c, -400,  400,  400, -400,  400, -400);
196            c.restore();
197        }
198
199        /*
200         * Draw a 3 dimensional line on to the screen
201         */
202        void drawLine(Canvas c, int x1, int y1, int z1, int x2, int y2, int z2) {
203            long now = SystemClock.elapsedRealtime();
204            float xrot = ((float)(now - mStartTime)) / 1000;
205            float yrot = (0.5f - mOffset) * 2.0f;
206            float zrot = 0;
207
208            // 3D transformations
209
210            // rotation around X-axis
211            float newy1 = (float)(Math.sin(xrot) * z1 + Math.cos(xrot) * y1);
212            float newy2 = (float)(Math.sin(xrot) * z2 + Math.cos(xrot) * y2);
213            float newz1 = (float)(Math.cos(xrot) * z1 - Math.sin(xrot) * y1);
214            float newz2 = (float)(Math.cos(xrot) * z2 - Math.sin(xrot) * y2);
215
216            // rotation around Y-axis
217            float newx1 = (float)(Math.sin(yrot) * newz1 + Math.cos(yrot) * x1);
218            float newx2 = (float)(Math.sin(yrot) * newz2 + Math.cos(yrot) * x2);
219            newz1 = (float)(Math.cos(yrot) * newz1 - Math.sin(yrot) * x1);
220            newz2 = (float)(Math.cos(yrot) * newz2 - Math.sin(yrot) * x2);
221
222            // 3D-to-2D projection
223            float startX = newx1 / (4 - newz1 / 400);
224            float startY = newy1 / (4 - newz1 / 400);
225            float stopX =  newx2 / (4 - newz2 / 400);
226            float stopY =  newy2 / (4 - newz2 / 400);
227
228            c.drawLine(startX, startY, stopX, stopY, mPaint);
229        }
230
231        /*
232         * Draw a circle around the current touch point, if any.
233         */
234        void drawTouchPoint(Canvas c) {
235            if (mTouchX >=0 && mTouchY >= 0) {
236                c.drawCircle(mTouchX, mTouchY, 80, mPaint);
237            }
238        }
239
240    }
241}
242