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      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 
     17 package com.android.internal.view;
     18 
     19 import android.graphics.Canvas;
     20 import android.graphics.PixelFormat;
     21 import android.graphics.Rect;
     22 import android.os.SystemClock;
     23 import android.util.Log;
     24 import android.view.Surface;
     25 import android.view.SurfaceHolder;
     26 
     27 import java.util.ArrayList;
     28 import java.util.concurrent.locks.ReentrantLock;
     29 
     30 public abstract class BaseSurfaceHolder implements SurfaceHolder {
     31     private static final String TAG = "BaseSurfaceHolder";
     32     static final boolean DEBUG = false;
     33 
     34     public final ArrayList<SurfaceHolder.Callback> mCallbacks
     35             = new ArrayList<SurfaceHolder.Callback>();
     36     SurfaceHolder.Callback[] mGottenCallbacks;
     37     boolean mHaveGottenCallbacks;
     38 
     39     public final ReentrantLock mSurfaceLock = new ReentrantLock();
     40     public Surface mSurface = new Surface();
     41 
     42     int mRequestedWidth = -1;
     43     int mRequestedHeight = -1;
     44     /** @hide */
     45     protected int mRequestedFormat = PixelFormat.OPAQUE;
     46     int mRequestedType = -1;
     47 
     48     long mLastLockTime = 0;
     49 
     50     int mType = -1;
     51     final Rect mSurfaceFrame = new Rect();
     52 
     53     public abstract void onUpdateSurface();
     54     public abstract void onRelayoutContainer();
     55     public abstract boolean onAllowLockCanvas();
     56 
     57     public int getRequestedWidth() {
     58         return mRequestedWidth;
     59     }
     60 
     61     public int getRequestedHeight() {
     62         return mRequestedHeight;
     63     }
     64 
     65     public int getRequestedFormat() {
     66         return mRequestedFormat;
     67     }
     68 
     69     public int getRequestedType() {
     70         return mRequestedType;
     71     }
     72 
     73     public void addCallback(Callback callback) {
     74         synchronized (mCallbacks) {
     75             // This is a linear search, but in practice we'll
     76             // have only a couple callbacks, so it doesn't matter.
     77             if (mCallbacks.contains(callback) == false) {
     78                 mCallbacks.add(callback);
     79             }
     80         }
     81     }
     82 
     83     public void removeCallback(Callback callback) {
     84         synchronized (mCallbacks) {
     85             mCallbacks.remove(callback);
     86         }
     87     }
     88 
     89     public SurfaceHolder.Callback[] getCallbacks() {
     90         if (mHaveGottenCallbacks) {
     91             return mGottenCallbacks;
     92         }
     93 
     94         synchronized (mCallbacks) {
     95             final int N = mCallbacks.size();
     96             if (N > 0) {
     97                 if (mGottenCallbacks == null || mGottenCallbacks.length != N) {
     98                     mGottenCallbacks = new SurfaceHolder.Callback[N];
     99                 }
    100                 mCallbacks.toArray(mGottenCallbacks);
    101             } else {
    102                 mGottenCallbacks = null;
    103             }
    104             mHaveGottenCallbacks = true;
    105         }
    106 
    107         return mGottenCallbacks;
    108     }
    109 
    110     public void ungetCallbacks() {
    111         mHaveGottenCallbacks = false;
    112     }
    113 
    114     public void setFixedSize(int width, int height) {
    115         if (mRequestedWidth != width || mRequestedHeight != height) {
    116             mRequestedWidth = width;
    117             mRequestedHeight = height;
    118             onRelayoutContainer();
    119         }
    120     }
    121 
    122     public void setSizeFromLayout() {
    123         if (mRequestedWidth != -1 || mRequestedHeight != -1) {
    124             mRequestedWidth = mRequestedHeight = -1;
    125             onRelayoutContainer();
    126         }
    127     }
    128 
    129     public void setFormat(int format) {
    130         if (mRequestedFormat != format) {
    131             mRequestedFormat = format;
    132             onUpdateSurface();
    133         }
    134     }
    135 
    136     public void setType(int type) {
    137         switch (type) {
    138         case SURFACE_TYPE_HARDWARE:
    139         case SURFACE_TYPE_GPU:
    140             // these are deprecated, treat as "NORMAL"
    141             type = SURFACE_TYPE_NORMAL;
    142             break;
    143         }
    144         switch (type) {
    145         case SURFACE_TYPE_NORMAL:
    146         case SURFACE_TYPE_PUSH_BUFFERS:
    147             if (mRequestedType != type) {
    148                 mRequestedType = type;
    149                 onUpdateSurface();
    150             }
    151             break;
    152         }
    153     }
    154 
    155     public Canvas lockCanvas() {
    156         return internalLockCanvas(null);
    157     }
    158 
    159     public Canvas lockCanvas(Rect dirty) {
    160         return internalLockCanvas(dirty);
    161     }
    162 
    163     private final Canvas internalLockCanvas(Rect dirty) {
    164         if (mType == SURFACE_TYPE_PUSH_BUFFERS) {
    165             throw new BadSurfaceTypeException(
    166                     "Surface type is SURFACE_TYPE_PUSH_BUFFERS");
    167         }
    168         mSurfaceLock.lock();
    169 
    170         if (DEBUG) Log.i(TAG, "Locking canvas..,");
    171 
    172         Canvas c = null;
    173         if (onAllowLockCanvas()) {
    174             Rect frame = dirty != null ? dirty : mSurfaceFrame;
    175             try {
    176                 c = mSurface.lockCanvas(frame);
    177             } catch (Exception e) {
    178                 Log.e(TAG, "Exception locking surface", e);
    179             }
    180         }
    181 
    182         if (DEBUG) Log.i(TAG, "Returned canvas: " + c);
    183         if (c != null) {
    184             mLastLockTime = SystemClock.uptimeMillis();
    185             return c;
    186         }
    187 
    188         // If the Surface is not ready to be drawn, then return null,
    189         // but throttle calls to this function so it isn't called more
    190         // than every 100ms.
    191         long now = SystemClock.uptimeMillis();
    192         long nextTime = mLastLockTime + 100;
    193         if (nextTime > now) {
    194             try {
    195                 Thread.sleep(nextTime-now);
    196             } catch (InterruptedException e) {
    197             }
    198             now = SystemClock.uptimeMillis();
    199         }
    200         mLastLockTime = now;
    201         mSurfaceLock.unlock();
    202 
    203         return null;
    204     }
    205 
    206     public void unlockCanvasAndPost(Canvas canvas) {
    207         mSurface.unlockCanvasAndPost(canvas);
    208         mSurfaceLock.unlock();
    209     }
    210 
    211     public Surface getSurface() {
    212         return mSurface;
    213     }
    214 
    215     public Rect getSurfaceFrame() {
    216         return mSurfaceFrame;
    217     }
    218 };
    219