1/*
2 * Copyright (C) 2013 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.gallery3d.filtershow.pipeline;
18
19import android.content.Context;
20import android.os.Handler;
21import android.os.Message;
22
23public abstract class ProcessingTask {
24    private ProcessingTaskController mTaskController;
25    private Handler mProcessingHandler;
26    private Handler mResultHandler;
27    private int mType;
28    private static final int DELAY = 300;
29
30    static interface Request {}
31    static interface Update {}
32    static interface Result {}
33
34    public boolean postRequest(Request message) {
35        Message msg = mProcessingHandler.obtainMessage(mType);
36        msg.obj = message;
37        if (isPriorityTask()) {
38            if (mProcessingHandler.hasMessages(getType())) {
39                return false;
40            }
41            mProcessingHandler.sendMessageAtFrontOfQueue(msg);
42        } else if (isDelayedTask()) {
43            if (mProcessingHandler.hasMessages(getType())) {
44                mProcessingHandler.removeMessages(getType());
45            }
46            mProcessingHandler.sendMessageDelayed(msg, DELAY);
47        } else {
48            mProcessingHandler.sendMessage(msg);
49        }
50        return true;
51    }
52
53    public void postUpdate(Update message) {
54        Message msg = mResultHandler.obtainMessage(mType);
55        msg.obj = message;
56        msg.arg1 = ProcessingTaskController.UPDATE;
57        mResultHandler.sendMessage(msg);
58    }
59
60    public void processRequest(Request message) {
61        Object result = doInBackground(message);
62        Message msg = mResultHandler.obtainMessage(mType);
63        msg.obj = result;
64        msg.arg1 = ProcessingTaskController.RESULT;
65        mResultHandler.sendMessage(msg);
66    }
67
68    public void added(ProcessingTaskController taskController) {
69        mTaskController = taskController;
70        mResultHandler = taskController.getResultHandler();
71        mProcessingHandler = taskController.getProcessingHandler();
72        mType = taskController.getReservedType();
73    }
74
75    public int getType() {
76        return mType;
77    }
78
79    public Context getContext() {
80        return mTaskController.getContext();
81    }
82
83    public abstract Result doInBackground(Request message);
84    public abstract void onResult(Result message);
85    public void onUpdate(Update message) {}
86    public boolean isPriorityTask() { return false; }
87    public boolean isDelayedTask() { return false; }
88}
89