Question

Previously I’ve been looking at existing code to display a map in a tab, and this time I’ve tried to write it myself to see if I understood it.

It runs fine without errors (screenshot), but I don’t completely understand why, and whether I’m doing this in the best way.

The part that I don’t quite understand is in the manifest.
I would have thought that android:label should be maptabview_name, but that gives me an error saying no matching resource was found.

Why does it run when using app_name for that activity?
Why can’t it find the maptabview_name resource?

Also, in MapTab2, is this the best way to start an intent?
What exactly is this telling the system? “I intend to start an activity from this class”?

Here’s my code
(It’s based on this):

MapTab2.java

package com.test.maptab2;

import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TabHost;

public class MapTab2 extends TabActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        Intent i = new Intent(this,MapTabView.class);

        TabHost.TabSpec spec;

        spec = getTabHost().newTabSpec("tab1");
        spec.setContent(i);
        spec.setIndicator("Map");
        getTabHost().addTab(spec);

        spec = getTabHost().newTabSpec("tab2");
        spec.setContent(R.id.detailstub);
        spec.setIndicator("Detail");
        getTabHost().addTab(spec);

        getTabHost().setCurrentTab(0);

    }

}

MapTabView.java

package com.test.maptab2;

import android.os.Bundle;
import com.google.android.maps.MapActivity;

public class MapTabView extends MapActivity {

    @Override
    public void onCreate (Bundle icicle){
        super.onCreate(icicle);
        setContentView(R.layout.maptabview);
    }

    @Override
    public boolean isRouteDisplayed(){
        return false;
    }

}

Main.xml

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content">

        <!-- Tab-switch panel -->
        <TabWidget android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"/>

        <!-- Tab contents -->
        <FrameLayout android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent">

            <!-- Map here -->
            <RelativeLayout android:id="@+id/mapstub"
                android:orientation="vertical"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"/>

            <!-- Other stuff -->
            <TextView android:id="@+id/detailstub"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="detail"/>

        </FrameLayout>  
    </LinearLayout>
</TabHost>

maptabview.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/maptablayout"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">

    <com.google.android.maps.MapView android:id="@+id/mapview"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:clickable="true"
        android:apiKey="0HRMcD5o6WrBVhmwbWpeyeavZ67PXWOvJeeCx2g"/>

</RelativeLayout>

MapTab2.Manifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.test.maptab2"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="3" />
    <uses-permission android:name="android.permission.INTERNET" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >

        <uses-library android:name="com.google.android.maps" />

        <!--  Main  -->
        <activity android:name=".MapTab2"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <!--  Map  -->
        <activity android:name=".MapTabView"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.EMBED" />
            </intent-filter>
        </activity>

    </application>
</manifest>

Answer 1

Q1: maptabview_name has to be in a string resource file, usually at res/values/string.xml, in case you have it there and still it’s not in the resources generated file (gen/package/R.java), try removing it and let eclipse generate it again.

Q2: AFAIK, TabHost.TabSpec.setContent(Intent intent) it’s like starting the Activity within the specified tab. I think that’s the way do do it when you deal with tabs. Since Intents are used to do a lot of things, this is a basic usage, in this case just to specify the class.