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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     Rect mTmpDirty;
     53 
     54     public abstract void onUpdateSurface();
     55     public abstract void onRelayoutContainer();
     56     public abstract boolean onAllowLockCanvas();
     57 
     58     public int getRequestedWidth() {
     59         return mRequestedWidth;
     60     }
     61 
     62     public int getRequestedHeight() {
     63         return mRequestedHeight;
     64     }
     65 
     66     public int getRequestedFormat() {
     67         return mRequestedFormat;
     68     }
     69 
     70     public int getRequestedType() {
     71         return mRequestedType;
     72     }
     73 
     74     public void addCallback(Callback callback) {
     75         synchronized (mCallbacks) {
     76             // This is a linear search, but in practice we'll
     77             // have only a couple callbacks, so it doesn't matter.
     78             if (mCallbacks.contains(callback) == false) {
     79                 mCallbacks.add(callback);
     80             }
     81         }
     82     }
     83 
     84     public void removeCallback(Callback callback) {
     85         synchronized (mCallbacks) {
     86             mCallbacks.remove(callback);
     87         }
     88     }
     89 
     90     public SurfaceHolder.Callback[] getCallbacks() {
     91         if (mHaveGottenCallbacks) {
     92             return mGottenCallbacks;
     93         }
     94 
     95         synchronized (mCallbacks) {
     96             final int N = mCallbacks.size();
     97             if (N > 0) {
     98                 if (mGottenCallbacks == null || mGottenCallbacks.length != N) {
     99                     mGottenCallbacks = new SurfaceHolder.Callback[N];
    100                 }
    101                 mCallbacks.toArray(mGottenCallbacks);
    102             } else {
    103                 mGottenCallbacks = null;
    104             }
    105             mHaveGottenCallbacks = true;
    106         }
    107 
    108         return mGottenCallbacks;
    109     }
    110 
    111     public void ungetCallbacks() {
    112         mHaveGottenCallbacks = false;
    113     }
    114 
    115     public void setFixedSize(int width, int height) {
    116         if (mRequestedWidth != width || mRequestedHeight != height) {
    117             mRequestedWidth = width;
    118             mRequestedHeight = height;
    119             onRelayoutContainer();
    120         }
    121     }
    122 
    123     public void setSizeFromLayout() {
    124         if (mRequestedWidth != -1 || mRequestedHeight != -1) {
    125             mRequestedWidth = mRequestedHeight = -1;
    126             onRelayoutContainer();
    127         }
    128     }
    129 
    130     public void setFormat(int format) {
    131         if (mRequestedFormat != format) {
    132             mRequestedFormat = format;
    133             onUpdateSurface();
    134         }
    135     }
    136 
    137     public void setType(int type) {
    138         switch (type) {
    139         case SURFACE_TYPE_HARDWARE:
    140         case SURFACE_TYPE_GPU:
    141             // these are deprecated, treat as "NORMAL"
    142             type = SURFACE_TYPE_NORMAL;
    143             break;
    144         }
    145         switch (type) {
    146         case SURFACE_TYPE_NORMAL:
    147         case SURFACE_TYPE_PUSH_BUFFERS:
    148             if (mRequestedType != type) {
    149                 mRequestedType = type;
    150                 onUpdateSurface();
    151             }
    152             break;
    153         }
    154     }
    155 
    156     public Canvas lockCanvas() {
    157         return internalLockCanvas(null);
    158     }
    159 
    160     public Canvas lockCanvas(Rect dirty) {
    161         return internalLockCanvas(dirty);
    162     }
    163 
    164     private final Canvas internalLockCanvas(Rect dirty) {
    165         if (mType == SURFACE_TYPE_PUSH_BUFFERS) {
    166             throw new BadSurfaceTypeException(
    167                     "Surface type is SURFACE_TYPE_PUSH_BUFFERS");
    168         }
    169         mSurfaceLock.lock();
    170 
    171         if (DEBUG) Log.i(TAG, "Locking canvas..,");
    172 
    173         Canvas c = null;
    174         if (onAllowLockCanvas()) {
    175             if (dirty == null) {
    176                 if (mTmpDirty == null) {
    177                     mTmpDirty = new Rect();
    178                 }
    179                 mTmpDirty.set(mSurfaceFrame);
    180                 dirty = mTmpDirty;
    181             }
    182 
    183             try {
    184                 c = mSurface.lockCanvas(dirty);
    185             } catch (Exception e) {
    186                 Log.e(TAG, "Exception locking surface", e);
    187             }
    188         }
    189 
    190         if (DEBUG) Log.i(TAG, "Returned canvas: " + c);
    191         if (c != null) {
    192             mLastLockTime = SystemClock.uptimeMillis();
    193             return c;
    194         }
    195 
    196         // If the Surface is not ready to be drawn, then return null,
    197         // but throttle calls to this function so it isn't called more
    198         // than every 100ms.
    199         long now = SystemClock.uptimeMillis();
    200         long nextTime = mLastLockTime + 100;
    201         if (nextTime > now) {
    202             try {
    203                 Thread.sleep(nextTime-now);
    204             } catch (InterruptedException e) {
    205             }
    206             now = SystemClock.uptimeMillis();
    207         }
    208         mLastLockTime = now;
    209         mSurfaceLock.unlock();
    210 
    211         return null;
    212     }
    213 
    214     public void unlockCanvasAndPost(Canvas canvas) {
    215         mSurface.unlockCanvasAndPost(canvas);
    216         mSurfaceLock.unlock();
    217     }
    218 
    219     public Surface getSurface() {
    220         return mSurface;
    221     }
    222 
    223     public Rect getSurfaceFrame() {
    224         return mSurfaceFrame;
    225     }
    226 
    227     public void setSurfaceFrameSize(int width, int height) {
    228         mSurfaceFrame.top = 0;
    229         mSurfaceFrame.left = 0;
    230         mSurfaceFrame.right = width;
    231         mSurfaceFrame.bottom = height;
    232     }
    233 };
    234