Develop Reference

Android: Stop Back Button From Exiting LockTask / Kiosk Mode

I want to implement a KioskMode, I'm targeting only Android L, since this is a very specific App.
I already went through the process of setting my App as DeviceAdmin, and
DevicePolicyManager.isLockTaskPermitted(this.getPackageName()) already returns true.
I then start a LockTask via startLockTask().
Everything is fine, but when I hold down the backbutton, the app still exits the kiosk mode.
I have overridden onKeyPress to show a custom Dialog for unlocking the app, but this does not hinder android to automatically exit my lock task if the user holds down back.
I don't really know what to do at the moment and would be thankful for every input.
I now have overridden
#Override
public boolean onKeyDown(int KeyCode, KeyEvent event)
{
if(KeyCode == KeyEvent.KEYCODE_BACK)
{
BackDownButtonPressed = true;
if(VolDownPressed)
showTaskLockDialog();
return true;
}
else if(KeyCode == KeyEvent.KEYCODE_VOLUME_DOWN)
{
VolDownPressed = true;
if(BackDownButtonPressed)
showTaskLockDialog();
return true;
}
return super.onKeyDown(KeyCode, event);
}
#Override
public boolean onKeyUp(int KeyCode, KeyEvent event) {
if(KeyCode == KeyEvent.KEYCODE_BACK)
{
BackDownButtonPressed = false;
return true;
}
else if(KeyCode == KeyEvent.KEYCODE_VOLUME_DOWN)
{
VolDownPressed = false;
return true;
}
return super.onKeyUp(KeyCode, event);
}
#Override
public void onBackPressed()
{
return;
}
#Override
public boolean onNavigateUp() {
return true;
}
#Override
public boolean dispatchKeyEvent (KeyEvent event)
{
if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
return true;
}
return true;
}
#Override
public boolean onKeyLongPress(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
//do something or nothing in your case
return true;
}
return super.onKeyLongPress(keyCode, event);
}
For the record, I am using a Samsung SM-T700 Tablet with Cyanogenmod CM12.1

Just to close this topic..
I couldn't figure out a perfect solution to this day. My current workaround is receiving an event if the user leaves the kiosk mode and just entering the kiosk mode again.
Sadly this leaves the user with 2 toasts saying "screen unpinned" and "screen pinned", which is unfortunate. But this satisfies my current needs.

Perhaps you need to override onKeyLongPress
#Override
public boolean onKeyLongPress(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
//do something or nothing in your case
return true
}
return super.onKeyLongPress(keyCode, event);
}

Not sure if it's helpful at all, but I wrote a blog about setting Kiosk Mode here:
http://www.sureshjoshi.com/mobile/android-kiosk-mode-without-root/
And also wrote sample code for it here:
https://github.com/sureshjoshi/android-kiosk-example
Not sure if you see any major differences between your code and mine, but I just tried to do a long press on a Samsung Galaxy Tab 4 running Android 5.0, and it won't exit the app.
Could it be something with rooting with Cyanogen?
If you don't have this in your code, perhaps add it in and check out if you see any problems:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Remove title bar and notification bar
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
ComponentName deviceAdmin = new ComponentName(this, AdminReceiver.class);
mDpm = (DevicePolicyManager) getSystemService(Context.DEVICE_POLICY_SERVICE);
if (!mDpm.isAdminActive(deviceAdmin)) {
Toast.makeText(this, getString(R.string.not_device_admin), Toast.LENGTH_SHORT).show();
}
if (mDpm.isDeviceOwnerApp(getPackageName())) {
mDpm.setLockTaskPackages(deviceAdmin, new String[]{getPackageName()});
} else {
Toast.makeText(this, getString(R.string.not_device_owner), Toast.LENGTH_SHORT).show();
}
mDecorView = getWindow().getDecorView();
}
and
protected void enableKioskMode(boolean enabled) {
try {
if (enabled) {
if (mDpm.isLockTaskPermitted(this.getPackageName())) {
startLockTask();
mIsKioskEnabled = true;
} else {
Toast.makeText(this, getString(R.string.kiosk_not_permitted), Toast.LENGTH_SHORT).show();
}
} else {
stopLockTask();
mIsKioskEnabled = false;
}
} catch (Exception e) {
// TODO: Log and handle appropriately
}
}

I have the same problem: How to stop "holding the back button" from escaping "Lock Task mode" on Android 6+
The issue only occurs on my Android 7 tablet.
Running the app on my Android 6 tablet fixed the problem.
Could you add some code to illustrate your current work-around?

Android - onKeyDown won't work with KEYCODE_MENU

Using onKeyDown with KEYCODE_MENU do nothing but it work with KEYCODE_SEARCH
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
switch(keyCode){
case KeyEvent.KEYCODE_MENU:
Toast.makeText(this, "Menu key pressed", Toast.LENGTH_SHORT).show();
return false;
case KeyEvent.KEYCODE_SEARCH:
Toast.makeText(this, "Search key pressed", Toast.LENGTH_SHORT).show();
return false;
}
return super.onKeyDown(keyCode, event);
}
I think there is something handling the menu key so it won't listen to my code
i have tried disbling onCreateOptionsMenu like this:
#Override
public boolean onCreateOptionsMenu(Menu menu) {
return true;
}
But still won't work..
So, any ideas to make the menu button listen to onKeyDown??

This may be a bug in appcompat v22. See https://code.google.com/p/android/issues/detail?id=159795
The workaround as posted in that thread is to override dispatchKeyEvent :
#Override
public boolean dispatchKeyEvent(KeyEvent event) {
int keyCode = event.getKeyCode();
int action = event.getAction();
boolean isDown = action == 0;
if (keyCode == KeyEvent.KEYCODE_MENU) {
return isDown ? this.onKeyDown(keyCode, event) : this.onKeyUp(keyCode, event);
}
return super.dispatchKeyEvent(event);
}
Edit: Please see Upgraded to AppCompat v22.1.0 and now onKeyDown and onKeyUp are not triggered when menu key is pressed

Even in use of Setup Box and Android TV
you can use dispatchKeyEvent in Activity and after that detect any key you want
#Override
public boolean dispatchKeyEvent(KeyEvent event) {
int code = event.getKeyCode();
int action = event.getAction();
boolean isDown = action == 0;
if (code == KeyEvent.KEYCODE_MENU) {
Toast.makeText(this, "Menu Is Selected", Toast.LENGTH_SHORT).show();
}
return super.dispatchKeyEvent(event);
}

What device and OS are you on ?
You may want to update your compat library to the latest ..
23.0.0

I need to minimize the android application on back button click

I need to minimize the application when back button is pressed.
I use following code to catch hardware back button click event
help me with the code of minimize on back key pressed
#Override
public boolean onKeyDown(int keyCode, keyEvent event) {
switch(keyCode) {
case KeyEvent.KEYCODE_BACK;
//minimize application
return true;
}
return super.onKeyDown(keyCode, event);
}

I think that you need to treat back event as home event. The code below is how I emulate home pressed when User press back button:
public void minimizeApp() {
Intent startMain = new Intent(Intent.ACTION_MAIN);
startMain.addCategory(Intent.CATEGORY_HOME);
startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(startMain);
}

This is a simple code to minimize the application
#Override
public void onBackPressed() {
this.moveTaskToBack(true);
}

try this code, this will minimize Activity.
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0)
{
this.moveTaskToBack(true);
return true;
}
return super.onKeyDown(keyCode, event);
}
or
If you want to close the activity use this.finish() method to close the current running activity. instead of this.moveTaskToBack(true);

Executing simple code on android app before closing

Hello, I've been trying to integrate airpush in andriod but I've been having some issues.
#Override public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && mWebView.canGoBack()) {
mWebView.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
As you can see is the andriod go back code for webview via history.
The problem is that I want execute this code when it has no more history, meaning when the application is about to close.
airpush.startLandingPageAd();
Any help will be greatly appreciated guys :)..

You need to edit your code, like this:
#Override public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK)) {
if(mWebView.canGoBack())
{
mWebView.goBack();
return true;
}
else
{
//Your webview doesn't have any history here and you can close your app here.
//You can also execute your Airpush code here.
airpush.startLandingPageAd();
return true;
}
}
return super.onKeyDown(keyCode, event);
}
I hope this helps.

Consider overriding onPause method of Activity for executing a piece of code before the activity hides.
#Override
protected void onPause() {
super.onPause();
airpush.startLandingPageAd();
}

Android: How can I set a listener to the MenuButton?

I want to do a custom action when pressing on the Menu button on the phone.
Is it possible to set an onClickListener (or similar) on the button and if so, how?
onCreateOptionsMenu is only called the first time the button is pressed - I've already tried this.

Usually you shouldn't override MENU behavior as users expect menu to appear, however you can use something along these lines:
/* (non-Javadoc)
* #see android.app.Activity#onKeyDown(int, android.view.KeyEvent)
*/
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ( keyCode == KeyEvent.KEYCODE_MENU ) {
Log.d(TAG, "MENU pressed");
return true;
}
return super.onKeyDown(keyCode, event);
}

But onPrepareOptionsMenu(..) is called each time. :)

Updated for AppCompat v.22.+
As mentioned in this forum, KeyDown is not called for KEYCODE_MENU button pressed.
The solution is to override dispatchKeyEvent to this way:
#Override
public boolean dispatchKeyEvent(KeyEvent event) {
int keyCode = event.getKeyCode();
int action = event.getAction();
boolean isDown = action == KeyEvent.ACTION_DOWN;
if (keyCode == KeyEvent.KEYCODE_MENU) {
return isDown ? this.onKeyDown(keyCode, event) : this.onKeyUp(keyCode, event);
}
return super.dispatchKeyEvent(event);
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ( keyCode == KeyEvent.KEYCODE_MENU ) {
// do what you want to do here
return true;
}
return super.onKeyDown(keyCode, event);
}
It works until Google developers release a fix for this (or maybe it is not a bug and it works this way from now on).

You could probably hack something in using "OnMenuOpened" or some such, but I really wouldn't recommend it. The menu button is only supposed to be used to show menus, so there is consistency between applications.