Mobile Platform as a Service:Load and customize the framework

Startup process

Application

When traditional Android apk starts running, the Application configured in android:name of application node in the AndroidManifest file is firstly loaded.

Since mPaaS Android framework has overridden the loading process, what configured in android:name should be the com.alipay.mobile.quinox.LauncherApplication class of mPaaS Android framework.

<application
    android:name="com.alipay.mobile.quinox.LauncherApplication"
    android:allowBackup="true"
    android:debuggable="true"
    android:hardwareAccelerated="false"
    android:icon="@drawable/appicon"
    android:label="@string/name"
    android:theme="@style/AppThemeNew" >
</application>

Startup page

Since it may be time-consuming for the framework to load the bundle, a startup page is required to redirect you to the application homepage when framework startup is completed. Therefore, the com.alipay.mobile.quinox.LauncherActivity application startup page that is provided by the mPaaS framework is configured in the AndroidManifest file.

The configuration is as follows:

<activity
android:name="com.alipay.mobile.quinox.LauncherActivity"
android:configChanges="orientation | keyboardHidden | navigation"
android:screenOrientation="portrait"
android:windowSoftInputMode="stateAlwaysHidden">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

To make developers have a better understanding of the startup process and avoid that the startup process is modified, deleted, or disturbed by mistake, the startup process of mPaaS is moderately encapsulated. So, the above LauncherApplication and LauncherActivity are invisible to the developers.

To enable that the client App implements its own initialization logic during the startup process, LauncherApplicationAgent and LauncherActivityAgent agents are designed in mPaaS. You can implement the App’s own initialization logic in the corresponding callback by inheriting the two classes. If you have defined these two classin bundle project, anti-obfuscation settings need to be done for these two classes when using ProGuard for code obfuscation, for more information, see Obfuscate Android codes.

Startup flow chart

The procedure of loading mPaaS Android framework is as follows:

1. When the framework is started, the main thread creates a startup page LauncherActivity, and then calls back the preInit method of LauncherActivityAgent.

2. The framework enables multidex. In the process, the framework calls back the preInit method of LauncherApplicationAgent, reads the description file of each bundle in the current .apk file, and creates the corresponding class loaders for all bundles.

3. After initialization, the framework calls the postInit methods of LauncherActivityAgent and LauncherApplicationAgent.

Customization

Actually, the framework has created two classes (MockLauncherApplicationAgent and MockLauncherActivityAgent) in Launcher project, and the two classes respectively inherit LauncherApplicationAgent and LauncherActivityAgent callback interfaces. Both interfaces are respectively called in LauncherAppliction and LauncherActivity during framework initialization.

Configure the AndroidManifest.xml file of the Portal as follows. You can also implement these two delegate classes in the Bundle, and modify the value of the corresponding meta-data in the above configuration.

     <application
          android:name="com.alipay.mobile.quinox.LauncherApplication" >

         <!-- Callback configuration of Application -->
         <meta-data
            android:name="agent.application"
            android:value="com.mpaas.demo.launcher.framework.MockLauncherApplicationAgent"/>

        <!-- Callback configuration of Activity -->
        <meta-data
            android:name="agent.activity"
            android:value="com.mpaas.demo.launcher.framework.MockLauncherActivityAgent"/>
        <!-- Layout configuration of the startup page -->
        <meta-data
            android:name="agent.activity.layout"
            android:value="layout_splash"/>

     </application>

Delegate classes

What configured in agent.application is the startup process delegate ApplicationAgent, shown as follows:

  public class MockLauncherApplicationAgent extends LauncherApplicationAgent {
      @Override
      protected void preInit() {
          super.preInit();
          //Before framework initialization
      }

      @Override
      protected void postInit() {
          super.postInit();
          //After framework initialization
      }
  }

The client App can perform application-level initialization in the implementation class of LauncherApplicationAgent. preInit() callback occurs before the framework initialization, so do not call the relevant interfaces of the framework (MicroApplicationContext) here. However, postInit() callback occurs after the framework initialization, you can use it.

What configured in agent.activity is the delegate of startup Activity, shown as follows:

public class MockLauncherActivityAgent extends LauncherActivityAgent {

        @Override
        public void preInit(Activity activity) {
                super.preInit(activity);
                //Before Launcher Activity startup
        }

        @Override
        public void postInit(final Activity activity) {
            super.postInit(activity);
                //After Launcher Activity startup
                //The logic of jumping to the homepage
                startActivity(activity,YOUR_ACTIVITY);
        }
}

Similar to LauncherApplicationAgent, the two callback of LauncherActivityAgent respectively happens before and after the framework initailization, and the methods used are also similar.

Modify startup page layout

The layout file of the startup page is also configured in the AndroidManifest.xml file of the Portal, shown as follows.

<application
android:name="com.alipay.mobile.quinox.LauncherApplication" >
<!-- Layout configuration of the startup page -->
<meta-data
android:name="agent.activity.layout"
android:value="layout_splash"/>

</application>

Modify the value to the name of the custom layout file.