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 17 package com.android.tv; 18 19 import android.app.Activity; 20 import android.content.ActivityNotFoundException; 21 import android.content.Context; 22 import android.content.Intent; 23 import android.os.Bundle; 24 import 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 30 * {@link 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 */ 35 public class LauncherActivity extends Activity { 36 private static final String TAG = "LauncherActivity"; 37 38 public static final String ERROR_MESSAGE 39 = "com.android.tv.LauncherActivity.ErrorMessage"; 40 41 private static final int REQUEST_CODE_DEFAULT = 0; 42 private static final int REQUEST_START_ACTIVITY = 100; 43 44 private static final String EXTRA_INTENT = "com.android.tv.LauncherActivity.INTENT"; 45 private static final String EXTRA_REQUEST_RESULT = 46 "com.android.tv.LauncherActivity.REQUEST_RESULT"; 47 48 /** 49 * Starts an activity by calling {@link Activity#startActivity}. 50 */ startActivitySafe(Activity baseActivity, Intent intentToLaunch)51 public static void startActivitySafe(Activity baseActivity, Intent intentToLaunch) { 52 // To avoid the app termination when the new activity crashes, LauncherActivity should be 53 // started by calling startActivityForResult(). 54 baseActivity.startActivityForResult(createIntent(baseActivity, intentToLaunch, false), 55 REQUEST_CODE_DEFAULT); 56 } 57 58 /** 59 * Starts an activity by calling {@link Activity#startActivityForResult}. 60 * 61 * <p>Note: {@code requestCode} should not be 0. The value is reserved for internal use. 62 */ startActivityForResultSafe(Activity baseActivity, Intent intentToLaunch, int requestCode)63 public static void startActivityForResultSafe(Activity baseActivity, Intent intentToLaunch, 64 int requestCode) { 65 if (requestCode == REQUEST_CODE_DEFAULT) { 66 throw new IllegalArgumentException("requestCode should not be 0."); 67 } 68 // To avoid the app termination when the new activity crashes, LauncherActivity should be 69 // started by calling startActivityForResult(). 70 baseActivity.startActivityForResult(createIntent(baseActivity, intentToLaunch, true), 71 requestCode); 72 } 73 createIntent(Context context, Intent intentToLaunch, boolean requestResult)74 private static Intent createIntent(Context context, Intent intentToLaunch, 75 boolean requestResult) { 76 Intent intent = new Intent(context, LauncherActivity.class); 77 intent.putExtra(EXTRA_INTENT, intentToLaunch); 78 if (requestResult) { 79 intent.putExtra(EXTRA_REQUEST_RESULT, true); 80 } 81 return intent; 82 } 83 84 @Override onCreate(Bundle savedInstanceState)85 public void onCreate(Bundle savedInstanceState) { 86 super.onCreate(savedInstanceState); 87 // We should launch the new activity in onCreate rather than in onStart. 88 // That's because it is not guaranteed that onStart is called only once. 89 Intent intent = getIntent().getParcelableExtra(EXTRA_INTENT); 90 boolean requestResult = getIntent().getBooleanExtra(EXTRA_REQUEST_RESULT, false); 91 try { 92 if (requestResult) { 93 startActivityForResult(intent, REQUEST_START_ACTIVITY); 94 } else { 95 startActivity(intent); 96 setResult(Activity.RESULT_OK); 97 finish(); 98 } 99 } catch (ActivityNotFoundException e) { 100 Log.w(TAG, "Activity not found for " + intent); 101 intent.putExtra(ERROR_MESSAGE, 102 getResources().getString(R.string.msg_missing_app)); 103 setResult(Activity.RESULT_CANCELED, intent); 104 finish(); 105 } 106 } 107 108 @Override onActivityResult(int requestCode, int resultCode, Intent data)109 public void onActivityResult(int requestCode, int resultCode, Intent data) { 110 setResult(resultCode, data); 111 finish(); 112 } 113 } 114