LauncherActivity.java revision a1589bd48e05abbee991e0cdd27fa402a5dc5001 
1/*
2 * Copyright (C) 2015 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.tv;
18
19import android.app.Activity;
20import android.content.ActivityNotFoundException;
21import android.content.Context;
22import android.content.Intent;
23import android.os.Bundle;
24import android.util.Log;
25
26/**
27 * An activity to launch a new activity.
28 *
29 * <p>In the case when {@link MainActivity} starts a new activity using {@link
30 * Activity#startActivity} or {@link Activity#startActivityForResult}, Live TV app is
31 * terminated if the new activity crashes. That's because the {@link android.app.ActivityManager}
32 * terminates the activity which is just below the crashed activity in the activity stack. To avoid
33 * this, we need to locate an additional activity between these activities in the activity stack.
34 */
35public class LauncherActivity extends Activity {
36    private static final String TAG = "LauncherActivity";
37
38    public static final String ERROR_MESSAGE = "com.android.tv.LauncherActivity.ErrorMessage";
39
40    private static final int REQUEST_CODE_DEFAULT = 0;
41    private static final int REQUEST_START_ACTIVITY = 100;
42
43    private static final String EXTRA_INTENT = "com.android.tv.LauncherActivity.INTENT";
44    private static final String EXTRA_REQUEST_RESULT =
45            "com.android.tv.LauncherActivity.REQUEST_RESULT";
46
47    /** Starts an activity by calling {@link Activity#startActivity}. */
48    public static void startActivitySafe(Activity baseActivity, Intent intentToLaunch) {
49        // To avoid the app termination when the new activity crashes, LauncherActivity should be
50        // started by calling startActivityForResult().
51        baseActivity.startActivityForResult(
52                createIntent(baseActivity, intentToLaunch, false), REQUEST_CODE_DEFAULT);
53    }
54
55    private static Intent createIntent(
56            Context context, Intent intentToLaunch, boolean requestResult) {
57        Intent intent = new Intent(context, LauncherActivity.class);
58        intent.putExtra(EXTRA_INTENT, intentToLaunch);
59        if (requestResult) {
60            intent.putExtra(EXTRA_REQUEST_RESULT, true);
61        }
62        return intent;
63    }
64
65    @Override
66    public void onCreate(Bundle savedInstanceState) {
67        super.onCreate(savedInstanceState);
68        // We should launch the new activity in onCreate rather than in onStart.
69        // That's because it is not guaranteed that onStart is called only once.
70        Intent intent = getIntent().getParcelableExtra(EXTRA_INTENT);
71        boolean requestResult = getIntent().getBooleanExtra(EXTRA_REQUEST_RESULT, false);
72        try {
73            if (requestResult) {
74                startActivityForResult(intent, REQUEST_START_ACTIVITY);
75            } else {
76                startActivity(intent);
77                setResult(Activity.RESULT_OK);
78                finish();
79            }
80        } catch (ActivityNotFoundException e) {
81            Log.w(TAG, "Activity not found for " + intent);
82            intent.putExtra(ERROR_MESSAGE, getResources().getString(R.string.msg_missing_app));
83            setResult(Activity.RESULT_CANCELED, intent);
84            finish();
85        }
86    }
87
88    @Override
89    public void onActivityResult(int requestCode, int resultCode, Intent data) {
90        setResult(resultCode, data);
91        finish();
92    }
93}
94