在CordovaActivity中添加原生View组件

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今天把移动Web站封装成了Android App，发现还是用Cordova封装方便，即使没有使用到任何原生的API， 主要是兼容性好，配置比用系统WebView方便太多了。默认继承的CordovaActivity只有一个WebView，因此没有不方便通过java代码添加View，通过重新makeWebView，createViews 2个方法可以实现使用自定义的layout, 方便的添加自己的原生组件。

代码如下

import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.view.View;
import android.view.animation.DecelerateInterpolator;
import android.widget.ImageButton;

import org.apache.cordova.CordovaActivity;
import org.apache.cordova.CordovaWebView;
import org.apache.cordova.CordovaWebViewImpl;
import org.apache.cordova.engine.SystemWebView;
import org.apache.cordova.engine.SystemWebViewEngine;

public class MainActivity extends CordovaActivity {


    /**
     * Called when the activity is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        super.init();
        loadUrl(launchUrl);
        ImageButton btnShare=(ImageButton)findViewById(R.id.btnShare);

        btnShare.setAlpha(0f);
        btnShare.animate()
                .alpha(1f)
                .setDuration(1500)
                .setInterpolator(new DecelerateInterpolator())
                .setStartDelay(1000);

        btnShare.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(Intent.ACTION_SEND);
                intent.setType("text/plain");
                intent.putExtra(Intent.EXTRA_SUBJECT, "分享");
                intent.putExtra(Intent.EXTRA_TEXT, "欢迎访问");
                startActivity(Intent.createChooser(intent, "分享到"));
            }

        });
    }

    @Override
    protected CordovaWebView makeWebView() {
        SystemWebView webView = (SystemWebView)findViewById(R.id.cordovaWebView);
        return new CordovaWebViewImpl(new SystemWebViewEngine(webView));
    }

    @Override
    protected void createViews() {
        //Why are we setting a constant as the ID? This should be investigated
//        appView.getView().setId(100);
//        appView.getView().setLayoutParams(new FrameLayout.LayoutParams(
//                ViewGroup.LayoutParams.MATCH_PARENT,
//                ViewGroup.LayoutParams.MATCH_PARENT));
//
//        setContentView(appView.getView());

        if (preferences.contains("BackgroundColor")) {
            int backgroundColor = preferences.getInteger("BackgroundColor", Color.BLACK);
            // Background of activity:
            appView.getView().setBackgroundColor(backgroundColor);
        }

        appView.getView().requestFocusFromTouch();
    }

}

更详细的介绍看下面的文章：

#Embed Cordova Webview in Android Native App
Some articles have shown how to embed cordova webview to android native application, for example:

• http://cordova.apache.org/docs/en/5.0.0/guide_platforms_android_webview.md.html
• http://richardgilmour.co.uk/2013/03/03/embedding-a-cordova-webview-in-a-native-android-app/
• https://github.com/Adobe-Marketing-Cloud-Apps/app-sample-android-phonegap/wiki/Embed-Webview-in-Android-Fragment

But unfortunately, the latest release of cordova android(4.0.0) make big changes on its code base. This changes, mostly kind of design pattern, have made the methods described in above article not work. What make me confused is that the cordova official website still use the old method in its example, which may waste others a lot of time.
This article will show how to cooperate with the new changes of cordova android to embed cordova webview in native android application.

##Create Cordova Android Project
First of all, we need to create a cordova android project. It is better to use cordova-cli.
cordova create test_cordova com.example.hello HelloWorld
cordova platform add android
cordova plugin add nl.x-services.plugins.toast
cordova plugin add org.apache.cordova.device
cordova build

• The first line of code create a new cordova project in folder test_cordova.
• The second line of code add android platform for new created project.
• The third and fourth line of code add two plugin for project(we will use these plugins in the example).
• The last line of code build the new created project

##Create Native Android Application
Google now suggest Android Studio for building android project, so we will use it here. Create a new project with blank activity using Android Studio. Here, the new created activity is called MainActivity.
public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void startCordovaActivity(View view) {
        Intent intent = new Intent(this, TestCordovaActivity.class);
        startActivity(intent);
    }

    public void startCordovaActivityWithLayout(View view) {
        Intent intent = new Intent(this, TestCordovaWithLayoutActivity.class);
        startActivity(intent);
    }

}

Nothing special, we just define two methods: startCordovaActivity and startCordovaActivity. These two method is bind with two buttons, which we will see later.

• startCordovaActivity will transfer to a new activity whose layout is a cordova webview created programmaticly.
• startCordovaActivity will transfer to a new activity whose layout is defined using xml layout file and embedded with a cordova webview.

Lets have a look at MainActivity’s layout xml file.

    <Button
        android:text="Start Cordova Activity Without Layout"
        android:onClick="startCordovaActivity"
        android:layout_width="200dp"
        android:layout_height="100dp" />

    <Button
        android:text="Start Cordova Activity With Layout"
        android:onClick="startCordovaActivityWithLayout"
        android:layout_width="200dp"
        android:layout_height="100dp"
        android:layout_marginTop="50dp"/>

</LinearLayout>

Two buttons are defined, corresponding to the two methods above.

###TestCordovaActivity
This activity is created to show how to create an activity with a cordova webview without the need of layout xml file.
public class TestCordovaActivity extends CordovaActivity {

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        super.init();
        // Load your application
         launchUrl = "file:///android_asset/www/index.html";
//        launchUrl = "file:///android_asset/www/index2.html";
        loadUrl(launchUrl);
   }
}

Noted that we extends the CordovaActivity , which is from cordova library and implement most of stuff in order to cooperate with a cordova webview. We don’t need to set the layout xml file usingsetContentView here, because the CordovaActivity create set it for us, a default cordova webview.

###TestCordovaWithLayoutActivity
This activity has its layout xml file.
public class TestCordovaWithLayoutActivity extends CordovaActivity {

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test_cordova_with_layout);
        super.init();
        // Load your application
        // launchUrl = "file:///android_asset/www/index.html"
        launchUrl = "file:///android_asset/www/index2.html";
        loadUrl(launchUrl);
    }

    @Override
    protected CordovaWebView makeWebView() {
        SystemWebView webView = (SystemWebView)findViewById(R.id.cordovaWebView);
        return new CordovaWebViewImpl(new SystemWebViewEngine(webView));
    }

    @Override
    protected void createViews() {
        //Why are we setting a constant as the ID? This should be investigated
//        appView.getView().setId(100);
//        appView.getView().setLayoutParams(new FrameLayout.LayoutParams(
//                ViewGroup.LayoutParams.MATCH_PARENT,
//                ViewGroup.LayoutParams.MATCH_PARENT));
//
//        setContentView(appView.getView());

        if (preferences.contains("BackgroundColor")) {
            int backgroundColor = preferences.getInteger("BackgroundColor", Color.BLACK);
            // Background of activity:
            appView.getView().setBackgroundColor(backgroundColor);
        }

        appView.getView().requestFocusFromTouch();
    }

}

Again, we need to extend the CordovaActivity. But this time, we use setContentView to set layout xml explicitly. In order to make things work, we need to override two methods: makeWebView andcreateViews.

• makeWebView is important, it use the R.id.cordovaWebView, which we define in layout xml file(we will see later).
• createViews is not so important, we override it just because it will use setContentView by default. But we want to use our xml, so just comment it.

The activity_test_cordova_with_layout.xml

    <TextView
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:background="#FF0000"
        android:textColor="#FFFFFF"
        android:gravity="center"
        android:text="This is native text view"
        />

    <org.apache.cordova.engine.SystemWebView
        android:id="@+id/cordovaWebView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        />

</LinearLayout>

We use a org.apache.cordova.engine.SystemWebView from cordova library. If you have read the articles listed above, you may remember that most of examples use org.apache.cordova.CordovaWebView. For example, below xml file is used in cordova official site.

This still works until release 4.0.0 … Now, the CordovaWebView class has changed to an interface. So we can not use like this anymore.

##Copy Cordova Android Project to Native Android Application
Now comes the most excited part, we need to copy useful stuff of cordova project to the native android project.

###cordova jar
The first and most important thing is that we need a cordova lib. You can download the latest cordova android 4.0.0 package, then create a jar file. Check the cordova offiicial website.

Navigate to the Android package’s /framework directory and run ant jar. It creates the Cordova .jar file, formed as /framework/cordova-x.x.x.jar.
After creating the jar file, we need to import it into our Android Studio project. Copy the jar file to libsfolder and add the follow line in build.gradle.
compile files(‘libs/cordova-4.0.0.jar’)

Try to access the class in cordova lib after you finish to see if everything is ok.

###www folder
Copy the www folder in cordova project to the android project. Note that the folder structure on the right is for Android Studio.
platforms/android/assets/www -> src/main/assets/www

###plugins
We have added plugins for cordova project above, so we need to add them to our android project.
We need to use the cordova plugins in folder platforms/android/src/, instead of plugins/, because when you run cordova build, cordova will copy the plugins in folder plugins/ to folderplatforms/android/src/ and perform some magic under the table(the config.xml indeed).
platforms/android/src/plugin_folder -> src/main/java/

###config.xml
Cordova use the config.xml for its configuration, likes plugins declarations. Note that do NOT use the file in root path of cordova project, use that in platforms folder instead.
platforms/android/res/xml/config.xml -> src/main/res/xml/

##Bonus
You can checkout the final project in github.