OverlayDisplayWindow.java revision 4ed8fe75e1dde1a2b9576f3862aecc5a572c56b5 
1/*
2 * Copyright (C) 2012 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.display;
18
19import android.content.Context;
20import android.graphics.SurfaceTexture;
21import android.hardware.display.DisplayManager;
22import android.util.Slog;
23import android.view.Display;
24import android.view.DisplayInfo;
25import android.view.GestureDetector;
26import android.view.Gravity;
27import android.view.LayoutInflater;
28import android.view.MotionEvent;
29import android.view.ScaleGestureDetector;
30import android.view.TextureView;
31import android.view.View;
32import android.view.WindowManager;
33import android.view.TextureView.SurfaceTextureListener;
34import android.widget.TextView;
35
36import java.io.PrintWriter;
37
38/**
39 * Manages an overlay window on behalf of {@link OverlayDisplayAdapter}.
40 * <p>
41 * This object must only be accessed on the UI thread.
42 * No locks are held by this object and locks must not be held while making called into it.
43 * </p>
44 */
45final class OverlayDisplayWindow {
46    private static final String TAG = "OverlayDisplayWindow";
47    private static final boolean DEBUG = false;
48
49    private final float INITIAL_SCALE = 0.5f;
50    private final float MIN_SCALE = 0.3f;
51    private final float MAX_SCALE = 1.0f;
52    private final float WINDOW_ALPHA = 0.8f;
53
54    // When true, disables support for moving and resizing the overlay.
55    // The window is made non-touchable, which makes it possible to
56    // directly interact with the content underneath.
57    private final boolean DISABLE_MOVE_AND_RESIZE = false;
58
59    private final Context mContext;
60    private final String mName;
61    private final int mWidth;
62    private final int mHeight;
63    private final int mDensityDpi;
64    private final int mGravity;
65    private final Listener mListener;
66    private final String mTitle;
67
68    private final DisplayManager mDisplayManager;
69    private final WindowManager mWindowManager;
70
71
72    private final Display mDefaultDisplay;
73    private final DisplayInfo mDefaultDisplayInfo = new DisplayInfo();
74
75    private View mWindowContent;
76    private WindowManager.LayoutParams mWindowParams;
77    private TextureView mTextureView;
78    private TextView mTitleTextView;
79
80    private GestureDetector mGestureDetector;
81    private ScaleGestureDetector mScaleGestureDetector;
82
83    private boolean mWindowVisible;
84    private int mWindowX;
85    private int mWindowY;
86    private float mWindowScale;
87
88    private float mLiveTranslationX;
89    private float mLiveTranslationY;
90    private float mLiveScale = 1.0f;
91
92    public OverlayDisplayWindow(Context context, String name,
93            int width, int height, int densityDpi, int gravity, Listener listener) {
94        mContext = context;
95        mName = name;
96        mWidth = width;
97        mHeight = height;
98        mDensityDpi = densityDpi;
99        mGravity = gravity;
100        mListener = listener;
101        mTitle = context.getResources().getString(
102                com.android.internal.R.string.display_manager_overlay_display_title,
103                mName, mWidth, mHeight, mDensityDpi);
104
105        mDisplayManager = (DisplayManager)context.getSystemService(
106                Context.DISPLAY_SERVICE);
107        mWindowManager = (WindowManager)context.getSystemService(
108                Context.WINDOW_SERVICE);
109
110        mDefaultDisplay = mWindowManager.getDefaultDisplay();
111        updateDefaultDisplayInfo();
112
113        createWindow();
114    }
115
116    public void show() {
117        if (!mWindowVisible) {
118            mDisplayManager.registerDisplayListener(mDisplayListener, null);
119            if (!updateDefaultDisplayInfo()) {
120                mDisplayManager.unregisterDisplayListener(mDisplayListener);
121                return;
122            }
123
124            clearLiveState();
125            updateWindowParams();
126            mWindowManager.addView(mWindowContent, mWindowParams);
127            mWindowVisible = true;
128        }
129    }
130
131    public void dismiss() {
132        if (mWindowVisible) {
133            mDisplayManager.unregisterDisplayListener(mDisplayListener);
134            mWindowManager.removeView(mWindowContent);
135            mWindowVisible = false;
136        }
137    }
138
139    public void relayout() {
140        if (mWindowVisible) {
141            updateWindowParams();
142            mWindowManager.updateViewLayout(mWindowContent, mWindowParams);
143        }
144    }
145
146    public void dump(PrintWriter pw) {
147        pw.println("    mWindowVisible=" + mWindowVisible);
148        pw.println("    mWindowX=" + mWindowX);
149        pw.println("    mWindowY=" + mWindowY);
150        pw.println("    mWindowScale=" + mWindowScale);
151        pw.println("    mWindowParams=" + mWindowParams);
152        if (mTextureView != null) {
153            pw.println("    mTextureView.getScaleX()=" + mTextureView.getScaleX());
154            pw.println("    mTextureView.getScaleY()=" + mTextureView.getScaleY());
155        }
156        pw.println("    mLiveTranslationX=" + mLiveTranslationX);
157        pw.println("    mLiveTranslationY=" + mLiveTranslationY);
158        pw.println("    mLiveScale=" + mLiveScale);
159    }
160
161    private boolean updateDefaultDisplayInfo() {
162        if (!mDefaultDisplay.getDisplayInfo(mDefaultDisplayInfo)) {
163            Slog.w(TAG, "Cannot show overlay display because there is no "
164                    + "default display upon which to show it.");
165            return false;
166        }
167        return true;
168    }
169
170    private void createWindow() {
171        LayoutInflater inflater = LayoutInflater.from(mContext);
172
173        mWindowContent = inflater.inflate(
174                com.android.internal.R.layout.overlay_display_window, null);
175        mWindowContent.setOnTouchListener(mOnTouchListener);
176
177        mTextureView = (TextureView)mWindowContent.findViewById(
178                com.android.internal.R.id.overlay_display_window_texture);
179        mTextureView.setPivotX(0);
180        mTextureView.setPivotY(0);
181        mTextureView.getLayoutParams().width = mWidth;
182        mTextureView.getLayoutParams().height = mHeight;
183        mTextureView.setOpaque(false);
184        mTextureView.setSurfaceTextureListener(mSurfaceTextureListener);
185
186        mTitleTextView = (TextView)mWindowContent.findViewById(
187                com.android.internal.R.id.overlay_display_window_title);
188        mTitleTextView.setText(mTitle);
189
190        mWindowParams = new WindowManager.LayoutParams(
191                WindowManager.LayoutParams.TYPE_DISPLAY_OVERLAY);
192        mWindowParams.flags |= WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
193                | WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS
194                | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
195                | WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
196                | WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED;
197        if (DISABLE_MOVE_AND_RESIZE) {
198            mWindowParams.flags |= WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
199        }
200        mWindowParams.privateFlags |=
201                WindowManager.LayoutParams.PRIVATE_FLAG_FORCE_HARDWARE_ACCELERATED;
202        mWindowParams.alpha = WINDOW_ALPHA;
203        mWindowParams.gravity = Gravity.TOP | Gravity.LEFT;
204        mWindowParams.setTitle(mTitle);
205
206        mGestureDetector = new GestureDetector(mContext, mOnGestureListener);
207        mScaleGestureDetector = new ScaleGestureDetector(mContext, mOnScaleGestureListener);
208
209        // Set the initial position and scale.
210        // The position and scale will be clamped when the display is first shown.
211        mWindowX = (mGravity & Gravity.LEFT) == Gravity.LEFT ?
212                0 : mDefaultDisplayInfo.logicalWidth;
213        mWindowY = (mGravity & Gravity.TOP) == Gravity.TOP ?
214                0 : mDefaultDisplayInfo.logicalHeight;
215        mWindowScale = INITIAL_SCALE;
216    }
217
218    private void updateWindowParams() {
219        float scale = mWindowScale * mLiveScale;
220        scale = Math.min(scale, (float)mDefaultDisplayInfo.logicalWidth / mWidth);
221        scale = Math.min(scale, (float)mDefaultDisplayInfo.logicalHeight / mHeight);
222        scale = Math.max(MIN_SCALE, Math.min(MAX_SCALE, scale));
223
224        float offsetScale = (scale / mWindowScale - 1.0f) * 0.5f;
225        int width = (int)(mWidth * scale);
226        int height = (int)(mHeight * scale);
227        int x = (int)(mWindowX + mLiveTranslationX - width * offsetScale);
228        int y = (int)(mWindowY + mLiveTranslationY - height * offsetScale);
229        x = Math.max(0, Math.min(x, mDefaultDisplayInfo.logicalWidth - width));
230        y = Math.max(0, Math.min(y, mDefaultDisplayInfo.logicalHeight - height));
231
232        if (DEBUG) {
233            Slog.d(TAG, "updateWindowParams: scale=" + scale
234                    + ", offsetScale=" + offsetScale
235                    + ", x=" + x + ", y=" + y
236                    + ", width=" + width + ", height=" + height);
237        }
238
239        mTextureView.setScaleX(scale);
240        mTextureView.setScaleY(scale);
241
242        mWindowParams.x = x;
243        mWindowParams.y = y;
244        mWindowParams.width = width;
245        mWindowParams.height = height;
246    }
247
248    private void saveWindowParams() {
249        mWindowX = mWindowParams.x;
250        mWindowY = mWindowParams.y;
251        mWindowScale = mTextureView.getScaleX();
252        clearLiveState();
253    }
254
255    private void clearLiveState() {
256        mLiveTranslationX = 0f;
257        mLiveTranslationY = 0f;
258        mLiveScale = 1.0f;
259    }
260
261    private final DisplayManager.DisplayListener mDisplayListener =
262            new DisplayManager.DisplayListener() {
263        @Override
264        public void onDisplayAdded(int displayId) {
265        }
266
267        @Override
268        public void onDisplayChanged(int displayId) {
269            if (displayId == mDefaultDisplay.getDisplayId()) {
270                if (updateDefaultDisplayInfo()) {
271                    relayout();
272                } else {
273                    dismiss();
274                }
275            }
276        }
277
278        @Override
279        public void onDisplayRemoved(int displayId) {
280            if (displayId == mDefaultDisplay.getDisplayId()) {
281                dismiss();
282            }
283        }
284    };
285
286    private final SurfaceTextureListener mSurfaceTextureListener =
287            new SurfaceTextureListener() {
288        @Override
289        public void onSurfaceTextureAvailable(SurfaceTexture surface, int width, int height) {
290            mListener.onWindowCreated(surface, mDefaultDisplayInfo.refreshRate);
291        }
292
293        @Override
294        public boolean onSurfaceTextureDestroyed(SurfaceTexture surface) {
295            mListener.onWindowDestroyed();
296            return true;
297        }
298
299        @Override
300        public void onSurfaceTextureSizeChanged(SurfaceTexture surface, int width, int height) {
301        }
302
303        @Override
304        public void onSurfaceTextureUpdated(SurfaceTexture surface) {
305        }
306    };
307
308    private final View.OnTouchListener mOnTouchListener = new View.OnTouchListener() {
309        @Override
310        public boolean onTouch(View view, MotionEvent event) {
311            // Work in screen coordinates.
312            final float oldX = event.getX();
313            final float oldY = event.getY();
314            event.setLocation(event.getRawX(), event.getRawY());
315
316            mGestureDetector.onTouchEvent(event);
317            mScaleGestureDetector.onTouchEvent(event);
318
319            switch (event.getActionMasked()) {
320                case MotionEvent.ACTION_UP:
321                case MotionEvent.ACTION_CANCEL:
322                    saveWindowParams();
323                    break;
324            }
325
326            // Revert to window coordinates.
327            event.setLocation(oldX, oldY);
328            return true;
329        }
330    };
331
332    private final GestureDetector.OnGestureListener mOnGestureListener =
333            new GestureDetector.SimpleOnGestureListener() {
334        @Override
335        public boolean onScroll(MotionEvent e1, MotionEvent e2,
336                float distanceX, float distanceY) {
337            mLiveTranslationX -= distanceX;
338            mLiveTranslationY -= distanceY;
339            relayout();
340            return true;
341        }
342    };
343
344    private final ScaleGestureDetector.OnScaleGestureListener mOnScaleGestureListener =
345            new ScaleGestureDetector.SimpleOnScaleGestureListener() {
346        @Override
347        public boolean onScale(ScaleGestureDetector detector) {
348            mLiveScale *= detector.getScaleFactor();
349            relayout();
350            return true;
351        }
352    };
353
354    /**
355     * Watches for significant changes in the overlay display window lifecycle.
356     */
357    public interface Listener {
358        public void onWindowCreated(SurfaceTexture surfaceTexture, float refreshRate);
359        public void onWindowDestroyed();
360    }
361}