Offer trampoline to help articles.

This allows other parts of the system internals to re-use common
logic for building help links, and it allows all help links to live
in a single common overlay.

Adds a help link slot for "Android is upgrading" notification.

Bug: 30033319, 30122837
Change-Id: I7dec3e63cfb8c7a8ee9a562cc61cb70f3f99fdae

AndroidManifest.xml

@@ -3043,6 +3043,12 @@
             </intent-filter>
         </service>
 
+        <activity android:name=".HelpTrampoline"
+            android:exported="true"
+            android:theme="@android:style/Theme.NoDisplay"
+            android:permission="android.permission.DUMP"
+            android:enabled="@bool/config_has_help" />
+
         <!-- This is the longest AndroidManifest.xml ever. -->
     </application>
 </manifest>

res/values/bools.xml

@@ -43,4 +43,7 @@
 
     <!--Whether the storage manager exists. -->
     <bool name="config_has_storage_manager">false</bool>
+
+    <!--Whether help links are defined. -->
+    <bool name="config_has_help">false</bool>
 </resources>

res/values/strings.xml

@@ -5661,6 +5661,8 @@
     <string name="help_url_gestures" translatable="false"></string>
     <!-- Help URL, Manage Storage [DO NOT TRANSLATE]-->
     <string name="help_url_manage_storage" translatable="false"></string>
+    <!-- Help URL, Android is upgrading [DO NOT TRANSLATE] -->
+    <string name="help_url_upgrading" translatable="false"></string>
 
     <!-- User account title [CHAR LIMIT=30] -->
     <string name="user_account_title">Account for content</string>

src/com/android/settings/HelpTrampoline.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings;
+
+import android.app.Activity;
+import android.content.ActivityNotFoundException;
+import android.content.Intent;
+import android.content.res.Resources;
+import android.os.Bundle;
+import android.util.Log;
+
+import com.android.settingslib.HelpUtils;
+
+public class HelpTrampoline extends Activity {
+    private static final String TAG = "HelpTrampoline";
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        try {
+            final String name = getIntent().getStringExtra(Intent.EXTRA_TEXT);
+            final int id = getResources().getIdentifier(name, "string", getPackageName());
+            final String value = getResources().getString(id);
+
+            final Intent intent = HelpUtils.getHelpIntent(this, value, null);
+            if (intent != null) {
+                startActivity(intent);
+            }
+
+        } catch (Resources.NotFoundException | ActivityNotFoundException e) {
+            Log.w(TAG, "Failed to resolve help", e);
+        }
+
+        finish();
+    }
+}