Android: How do you set up the TabHost

Question

I am trying to use the tabhost when I add it to my xml it doesn't look right, and I believe there is something that needs to be done in java, I am trying to set up three tabs with three different classes is this possible?

Here is my xml:

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

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent" >

        <TabHost
            android:id="@android:id/tabhost"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1" >

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical" >

                <TabWidget
                    android:id="@android:id/tabs"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content" >
                </TabWidget>

                <FrameLayout
                    android:id="@android:id/tabcontent"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent" >

                    <LinearLayout
                        android:id="@+id/tab1"
                        android:layout_width="match_parent"
                        android:layout_height="match_parent" >

                        <TextView
                            android:id="@+id/textView1"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:text="Browser History:"
                            android:textAppearance="?android:attr/textAppearanceLarge" />

                        <TextView
                            android:id="@+id/hello"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content" />
                    </LinearLayout>

                    <LinearLayout
                        android:id="@+id/tab2"
                        android:layout_width="match_parent"
                        android:layout_height="match_parent" >

                        <TextView
                            android:id="@+id/textView2"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:text="Call Log"
                            android:textAppearance="?android:attr/textAppearanceLarge" />

                        <TextView
                            android:id="@+id/call"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content" />
                    </LinearLayout>

                    <LinearLayout
                        android:id="@+id/tab3"
                        android:layout_width="match_parent"
                        android:layout_height="match_parent" >

                        <TextView
                            android:id="@+id/textView3"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content"
                            android:text="Text Messages"
                            android:textAppearance="?android:attr/textAppearanceLarge" />

                        <TextView
                            android:id="@+id/tvSms"
                            android:layout_width="wrap_content"
                            android:layout_height="wrap_content" />
                    </LinearLayout>
                </FrameLayout>
            </LinearLayout>
        </TabHost>
    </LinearLayout>

</LinearLayout> 

And I have three different classes, because I am trying to use each tab to open each activity.

Here are the Classes

  package com.johnnydicamillo.spybeta;

import android.app.Activity;
import android.app.TabActivity;
import android.content.Intent;
import android.content.res.Resources;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.Browser;
import android.widget.TabHost;
import android.widget.TextView;

public class AndroidSpybetaActivity extends TabActivity {
    /** Called when the activity is first created. */
    Resources res;
    TabHost tabHost;
    Intent intent;

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

        res = getResources();
        tabHost = getTabHost();
        TabHost.TabSpec spec;

        intent = new Intent().setClass(this, Messaging.class);
        spec = tabHost.newTabSpec("messaging").setIndicator("Messaging")
                .setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, TestingData.class);
        spec = tabHost.newTabSpec("Calls").setIndicator("Calls")
                .setContent(intent);
        tabHost.addTab(spec);
        tabHost.setCurrentTab(0);

        TextView view = (TextView) findViewById(R.id.hello);
        Cursor mCur = managedQuery(android.provider.Browser.BOOKMARKS_URI,
                null, null, null, null);
        mCur.moveToFirst();
        int index = mCur.getColumnIndex(Browser.BookmarkColumns.TITLE);
        while (mCur.isAfterLast() == false) {
            view.append(" WebSite " + mCur.getString(index));
            mCur.moveToNext();
        }
    }
}

Second

package com.johnnydicamillo.spybeta;

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class Messaging extends TabActivity{
    static TextView messageBox;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        messageBox = (TextView) findViewById(R.id.tvSms);

    }
    public static void updateMessageBox(String msg) {
        messageBox.append(msg);
    }

}

and third

package com.johnnydicamillo.spybeta;

import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.CallLog;
import android.provider.CallLog.Calls;
import android.widget.TextView;

public class TestingData extends TabActivity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        TextView view = (TextView) findViewById(R.id.call);
        String[] projection = new String[] {

        Calls.NUMBER

        };
        Cursor mCur = managedQuery(CallLog.Calls.CONTENT_URI, projection,
                Calls.DURATION + "<?", new String[] { "60" }, Calls.DURATION
                        + " ASC");
        mCur.moveToFirst();

        while (mCur.isAfterLast() == false) {
            for (int i = 0; i < mCur.getColumnCount(); i++) {
                view.append(" Number " + mCur.getString(i));
            }
            mCur.moveToNext();
        }
    }
}

Here is my logcat:

08-12 15:19:16.368: D/AndroidRuntime(280): Shutting down VM
08-12 15:19:16.368: W/dalvikvm(280): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
08-12 15:19:16.628: E/AndroidRuntime(280): FATAL EXCEPTION: main
08-12 15:19:16.628: E/AndroidRuntime(280): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.johnnydicamillo.spybeta/com.johnnydicamillo.spybeta.AndroidSpybetaActivity}: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.johnnydicamillo.spybeta/com.johnnydicamillo.spybeta.Messaging}; have you declared this activity in your AndroidManifest.xml?
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.os.Handler.dispatchMessage(Handler.java:99)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.os.Looper.loop(Looper.java:123)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.ActivityThread.main(ActivityThread.java:4627)
08-12 15:19:16.628: E/AndroidRuntime(280):  at java.lang.reflect.Method.invokeNative(Native Method)
08-12 15:19:16.628: E/AndroidRuntime(280):  at java.lang.reflect.Method.invoke(Method.java:521)
08-12 15:19:16.628: E/AndroidRuntime(280):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
08-12 15:19:16.628: E/AndroidRuntime(280):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
08-12 15:19:16.628: E/AndroidRuntime(280):  at dalvik.system.NativeStart.main(Native Method)
08-12 15:19:16.628: E/AndroidRuntime(280): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {com.johnnydicamillo.spybeta/com.johnnydicamillo.spybeta.Messaging}; have you declared this activity in your AndroidManifest.xml?
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.Instrumentation.checkStartActivityResult(Instrumentation.java:1404)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.ActivityThread.resolveActivityInfo(ActivityThread.java:2473)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.LocalActivityManager.startActivity(LocalActivityManager.java:277)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.widget.TabHost$IntentContentStrategy.getContentView(TabHost.java:651)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.widget.TabHost.setCurrentTab(TabHost.java:323)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.widget.TabHost.addTab(TabHost.java:213)
08-12 15:19:16.628: E/AndroidRuntime(280):  at com.johnnydicamillo.spybeta.AndroidSpybetaActivity.onCreate(AndroidSpybetaActivity.java:31)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-12 15:19:16.628: E/AndroidRuntime(280):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
08-12 15:19:16.628: E/AndroidRuntime(280):  ... 11 more
08-12 15:19:21.929: I/Process(280): Sending signal. PID: 280 SIG: 9

Answer 1

Yes, it is possible.

You can specify each activity (Start an intent) for each tabs in the following manner

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

        res = getResources();
        tabHost = getTabHost();
        TabHost.TabSpec spec;


        intent = new Intent().setClass(this, CalendarActivity.class);
        spec = tabHost.newTabSpec("calendar").setIndicator("Calendar", res.getDrawable(R.drawable.ic_tab_calendar)).setContent(intent);
        tabHost.addTab(spec);

        intent = new Intent().setClass(this, ProfileActivity.class);
        spec = tabHost.newTabSpec("profile").setIndicator("Profile", res.getDrawable(R.drawable.ic_tab_profile)).setContent(intent);
        tabHost.addTab(spec);

        tabHost.setCurrentTab(0);
}

Each activity will have their own content layout views, therefore no need to worry about that in the main layout.

Your main XML layout will be small and simple as

<?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="match_parent"
    android:layout_height="match_parent" >

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:padding="5dp" >

        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"/>

        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:padding="5dp" />
    </LinearLayout>

</TabHost>

I think this is what you want.

Answer 2

It is not possible to have a tab correspond to an activity. The purpose of tabs is to break up one activity into how ever many views if there is too much info display in one view(not to be confused with activity). Here however is how you set up TabHost: First start with an xml:

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

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

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

        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent" >

            <AnalogClock
                android:id="@+id/tab1"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent" />

            <Button
                android:id="@+id/tab2"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent"
                android:text="A semi-random button" />
        </FrameLayout>
    </LinearLayout>
</TabHost>

Sorry that's hard to read but if you copy it into eclipse you should be fine. And then the Java:

    import android.app.Activity;
import android.os.Bundle;
import android.widget.TabHost;

public class TabDemo extends Activity {
    @Override
    public void onCreate(Bundle icicle) {
        super.onCreate(icicle);
        setContentView(R.layout.main);

        TabHost tabs=(TabHost)findViewById(R.id.tabhost); //Id of tab host

        tabs.setup();

        TabHost.TabSpec spec=tabs.newTabSpec("tag1");//make a new tab

        spec.setContent(R.id.tab1);  //What is in the tab (not an activity but rather a view)
        spec.setIndicator("Clock"); //Name of tab
        tabs.addTab(spec); //Add it 

        spec=tabs.newTabSpec("tag2"); //Same thing here
        spec.setContent(R.id.tab2);
        spec.setIndicator("Button");
        tabs.addTab(spec);
    }
}

This is relatively simple an I am sure there is support in the android development website and of course just searching on Google. This code was copied out of Beginning Android 4 by Grant Allen and the book explains this topic in much greater detail. Good luck!