Android: change default Home Application

Question

for some specific requirement I am required to change Android Default Home application with my customized Home application ( a setting inside my app that will toggle default home = my application or previous home)

I don't want the user to travel android settings that are very complicated.

Can any one help me out like where it registers launcher.apk for default home application or how to change that

The only thing I could find was that old question: How to change default Android's Desktop application?

but no answers at all.

I have seen HomeSwitcher in the Market that do the trick, but no answer for the developer that might certainly be busy.

EDIT

I found this on the web http://www.mail-archive.com/[email protected]/msg74167.html

But I got the same issue:

this is my code:

    private void makePreferred() {
            PackageManager pm = getPackageManager();
            IntentFilter f = new IntentFilter("android.intent.action.MAIN");
            f.addCategory("android.intent.category.HOME");
            f.addCategory("android.intent.category.DEFAULT");
            ComponentName cn = new ComponentName("com.example.android.home", "com.example.android.home.Home");
            pm.addPreferredActivity(f, IntentFilter.MATCH_CATEGORY_EMPTY, null, cn);

I have the android.permission.SET_PREFERRED_APPLICATIONS set in the manifest. After executing the code above, the logs claim things have been added like expected (same logs as when I tick off "Make default" from IntentResolver's list). However, when I proceed by clicking home, the list still shows up and the logs say:

INFO/PackageManager(52): Result set changed, dropping preferred
activity for Intent { act=android.intent.action.MAIN cat=
[android.intent.category.HOME] flg=0x10200000 } type null

So it seems the resolver deletes the default entry. Am I doing something wrong, or is this a security measure? What are the ideas behind this?

Sudor

I'm pretty sure you can't force a user to use your intent as the default for anything - it should always be their choice. Registering it as a Home intent should be enough for the user to get a dialog asking which home app they want to launch. – Machiavellian

This is not possible UNLESS you are working with a primary build for a phone and even then its still risky. Consider telling your requester NO. Because this is not expected behavior from an apps perspective. – Brokenhearted

Answer 1

I did an extensive research on that and starting from 2.2 there is no way to do that. The only way is using some hacking that toddler lock app does but this app put samsung phones recently in the infinite loop, so it is a risky approach.

if you look at the froyo source code here of packagemanager class, you will see this small condition in the addPreferredActivity method:

if (getUidTargetSdkVersionLockedLP(Binder.getCallingUid())
                     < Build.VERSION_CODES.FROYO) {
                 Slog.w(TAG, "Ignoring addPreferredActivity() from uid"
                        + Binder.getCallingUid());
                 return;
             }

HomeSwitcher does not work properly on 2.2 since it uses this very method and developer made a comment on app page "Froyo(2.2) is not supported due to the API change"

Darken

The OP isn't hitting that thoug. His error is "dropping preferred activity..." which is generated further down in the code. All that check does is prevent you calling addPreferredActivity from an applicaiton which wasn't built against Froyo. – Vasty

Answer 2

"Result set changed" means that the set of packages matching that intent has changed from the set you specified when you created the default - - so the default is no longer valid. Your list of components (which you are currently setting to null) needs to contain all homescreen apps present on device, not just yours.

Here's example code that I have tested (using adb shell am start http://www.google.co.uk/ ) and used to set the default browser. XXX represents a customer name that I had to black out.

Note that in order to call addPreferredActivity you must have compiled against a minimum-sdk version of 8 (2.2) and you must have specified the SET_PREFERRED_APPLICATIONS permission. That permission is protection level 2, so you need to be signed with the same certificate as PackageManager.

IntentFilter filter = new IntentFilter();
filter.addAction("android.intent.action.VIEW");
filter.addCategory("android.intent.category.DEFAULT");
filter.addDataScheme("http");
Context context = getApplicationContext();
ComponentName component = new ComponentName("com.opera.mini.XXX", "com.opera.mini.XXX.CustomerBrowser");
ComponentName[] components = new ComponentName[] {new ComponentName("com.android.browser", "com.android.browser.BrowserActivity"),
                                                  component};
pm.addPreferredActivity(filter, IntentFilter.MATCH_CATEGORY_SCHEME, components, component);

ETA - if you marked this response down, could you let me know why. The code I posted above is tested and working...

Vasty

how to sign it with the same certificate? – Danby

I also want to implement it, I want to change the default launcher after the first booting. I have put the code to the PackageManagerService's constructor, but it always failed. Can you tell me If I want to do it, which position should I put the code? thanks very much! – Paraformaldehyde

@Danby you would need the platform keys that the OS was built with. Unless you're building and signing your own ROM, you wouldn't have access to these. – Sukin

What is pm? It's not initialized – Cosgrave

Answer 3

startActivity(new Intent(Settings.ACTION_HOME_SETTINGS));

Reserved

This takes to settings and enables you to manually set the Home Launcher, but does not set it back to the default Launcher programmatically. – Firehouse

Answer 4

This code works on my ICS device: I use a service that is sensible to some call, one of them is called SET_PREFERRED_LAUNCHER, the put in a bundle your new default Launcher package (PREFERRED_PACKAGE_KEY) and it's activity (PREFERRED_ACTIVITY_KEY)

Method installPackageMethod = null;
Method deletePackageMethod = null;
Method setPreferredActivityMethod = null;
Method replacePreferredActivityMethod = null;
Object pm = null;


    @Override
public void onCreate() {
    super.onCreate();
        if (pm == null)
        pm = getPackageManager();
    try {
        if (setPreferredActivityMethod == null)
            setPreferredActivityMethod = pm.getClass().getMethod(
                    "addPreferredActivity", IntentFilter.class, int.class,
                    ComponentName[].class, ComponentName.class);
    } catch (NoSuchMethodException e) {
        e.printStackTrace();
    }
}


private final class ServiceHandler extends Handler {
    private Context context;

    public ServiceHandler(Looper looper, Context ctx) {
        super(looper);
        context = ctx;
    }

    @Override
    public void handleMessage(Message msg) {
        Intent intent = (Intent) msg.getData().getParcelable(
                UPDATER_SERVICE_ACTION);
        int request = intent.getIntExtra(
                REQUEST_KEY,
                REQUEST_UNKNOWN);
        Bundle bundle = intent.getExtras();

        switch (request) {
        case INSTALL_APPLICATION: {
            if (bundle != null) {
                String appPath = bundle
                        .getString(APP_PATH_KEY);
                if (appPath != null) {
                    LogUtil.e(TAG, "try to install " + appPath);

                    try {
                        am.installPackage(appPath);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }

                    LogUtil.e(TAG, "install of " + appPath + " done");
                }
            }
            break;
        }
        case UNISTALL_PACKAGE: {
            if (bundle != null) {
                String packagename = bundle
                        .getString(PACKAGE_NAME_KEY);
                if (packagename != null) {
                    LogUtil.e(TAG, "unistall " + packagename);

                    try {
                        deletePackageMethod
                                .invoke(pm, packagename, null, 0);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
            break;
        }
        case SET_PREFERRED_LAUNCHER: {
            if (bundle != null) {
                String package_name = bundle
                        .getString(PREFERRED_PACKAGE_KEY);
                if (package_name == null) {
                    LogUtil.e(TAG,
                            "WARNING: setDefaultActivity cannot continue, package is NULL");
                    return;
                }
                String activity_name = bundle
                        .getString(PREFERRED_ACTIVITY_KEY);
                if (activity_name == null) {
                    LogUtil.e(TAG,
                            "WARNING: setDefaultActivity cannot continue, activity is NULL");
                    return;
                }

                LogUtil.e(TAG, "setDefaultActivity activity="
                        + activity_name + " package=" + package_name);

                IntentFilter filter = new IntentFilter(
                        "android.intent.action.MAIN");
                filter.addCategory("android.intent.category.HOME");
                filter.addCategory("android.intent.category.DEFAULT");
                ComponentName[] components = new ComponentName[] {
                        new ComponentName("com.android.launcher",
                                "com.android.launcher2.Launcher"),
                        new ComponentName(package_name, activity_name) };
                ComponentName activity = new ComponentName(package_name,
                        activity_name);
                try {
                    setPreferredActivityMethod.invoke(pm, filter,
                            IntentFilter.MATCH_CATEGORY_EMPTY, components,
                            activity);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
        }

    }

}

Remember to add in your manifest file this permission:

    <uses-permission android:name="android.permission.SET_PREFERRED_APPLICATIONS"/>

Usage:

    public void setPreferredLauncher(String activity_name,String package_name)
{
    Intent intent = new Intent(UPDATER_SERVICE_ACTION);
    intent.putExtra(REQUEST_KEY, SET_PREFERRED_LAUNCHER);
    intent.putExtra(PREFERRED_ACTIVITY_KEY, activity_name);
    intent.putExtra(PREFERRED_PACKAGE_KEY, package_name);
    context.startService(intent);
}

where:

    public static final String _UPDATER_SERVICE_ACTION = "com.android.updaterservice.ACTION";
public static final String REQUEST_KEY = "com.android.updaterservice.REQUEST_KEY";
public static final String PACKAGE_NAME_KEY = "com.android.updaterservice.PACKAGE_NAME_KEY";
public static final String APP_PATH_KEY = "com.android.updaterservice.APP_PATH_KEY";
public static final String PREFERRED_ACTIVITY_KEY = "com.android.updaterservice.PREFERRED_ACTIVITY_KEY";
public static final String PREFERRED_PACKAGE_KEY = "com.android.updaterservice.PREFERRED_PACKAGE_KEY";
public static final String INSTALL_PACKAGE_RESULT = "com.android.updaterservice.INSTALL_PACKAGE_RESULT";
public static final String PACKAGE_NAME = "PACKAGE_NAME";
public static final String INSTALL_SUCCEEDED = "INSTALL_SUCCEEDED";
public static final int REQUEST_UNKNOWN = -1;
public static final int INSTALL_APPLICATION = 1;
public static final int UNISTALL_PACKAGE = 2;
public static final int SET_PREFERRED_LAUNCHER = 3;

Muirhead

Note that only apps signed with the same signing key as signed the firmware can hold the SET_PREFERRED_APPLICATIONS permission. – Dekow

At am.installPackage()..what is am? what to declare? and there is no use of serviceHandler.. please update it properly – Hackamore