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
17
18package android.filterpacks.base;
19
20import android.filterfw.core.Filter;
21import android.filterfw.core.FilterContext;
22import android.filterfw.core.Frame;
23import android.filterfw.core.GenerateFieldPort;
24import android.filterfw.core.GenerateFinalPort;
25import android.os.Handler;
26import android.os.Looper;
27
28import java.lang.Runnable;
29
30/**
31 * @hide
32 */
33public class CallbackFilter extends Filter {
34
35    @GenerateFieldPort(name = "listener", hasDefault = true)
36    private FilterContext.OnFrameReceivedListener mListener;
37
38    @GenerateFieldPort(name = "userData", hasDefault = true)
39    private Object mUserData;
40
41    @GenerateFinalPort(name = "callUiThread", hasDefault = true)
42    private boolean mCallbacksOnUiThread = true;
43
44    private Handler mUiThreadHandler;
45
46    private class CallbackRunnable implements Runnable {
47        private Filter mFilter;
48        private Frame mFrame;
49        private Object mUserData;
50        private FilterContext.OnFrameReceivedListener mListener;
51
52        public CallbackRunnable(FilterContext.OnFrameReceivedListener listener, Filter filter, Frame frame, Object userData) {
53            mListener = listener;
54            mFilter = filter;
55            mFrame = frame;
56            mUserData = userData;
57        }
58
59        public void run() {
60            mListener.onFrameReceived(mFilter, mFrame, mUserData);
61            mFrame.release();
62        }
63    }
64
65    public CallbackFilter(String name) {
66        super(name);
67    }
68
69    @Override
70    public void setupPorts() {
71        addInputPort("frame");
72    }
73
74    public void prepare(FilterContext context) {
75        if (mCallbacksOnUiThread) {
76            mUiThreadHandler = new Handler(Looper.getMainLooper());
77        }
78    }
79
80    public void process(FilterContext context) {
81        // Get frame and forward to listener
82        final Frame input = pullInput("frame");
83        if (mListener != null) {
84            if (mCallbacksOnUiThread) {
85                input.retain();
86                CallbackRunnable uiRunnable = new CallbackRunnable(mListener, this, input, mUserData);
87                if (!mUiThreadHandler.post(uiRunnable)) {
88                    throw new RuntimeException("Unable to send callback to UI thread!");
89                }
90            } else {
91                mListener.onFrameReceived(this, input, mUserData);
92            }
93        } else {
94            throw new RuntimeException("CallbackFilter received frame, but no listener set!");
95        }
96    }
97
98}
99