how to detect shake event when my phone is in lock state - android

I read this unable to detect shake event when my phones screen is off in android article. But this question is differ from this.
I created an application which speak (using TextToSpeach API) time when I shake device. For that I have created a "Service" in which "ShakeListener" was registered. While I shake device, it will speak current time.
But this works fine while my device is "ON". When I lock my device, it stops working. Can any one elaborate what is the problem behind?

I think the problem here is that when you lock the device, it goes to sleep mode. And your ShakeListener doesn't receive shake events. The best way to implement what you want would be to register broadcast receiver to receive shake events. But as I know, android doesn't provide such broadcast. Another solution is to acuire a partial WakeLock. It'll prevent android from sleep. But of course it'll cause battery issues. Also take a look on this thread: Android accelerometer not working when screen is turned off

Probably you can not receive this notification until you patch some kernel implementation. Android doesn't broadcast such notification.

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Broadcast Receiver for volume up button

I am aware that this question has been asked already in this site, but I could not find my answer. SO this is what i am trying ot do. My power button in my phone is not working properly. So could is there a way to override my volume up button to unlock my phone.
I am planning to implement broadcast receiver But could not find the appropriate intent-filter. Another alternative that I thought was to run a service when the screen is locked, but I am not quite sure if I can listen to key events.
So if any of the above mentioned is possible, could you hint on how to get it done or suggest another alternative?
No, It do not think so. This can not be done.
There is no broadcast for volume up or down button presently. You can implement a service that will listen for any changes in the volume but it is not recommended to run a service all the time since that consumes both battery and memory.
The only solution that I can think of is using ContentObservers for listening to the changes in the settings such as volume of streams. This answer here will provide you with the code to use ContentObserver to listen for volume up or down. https://stackoverflow.com/a/7017516/1979347
This functionality you speak of has already been done multiple times and can be found on Google Play. However, I'm not sure how they did it, or how much their solution drains the battery.
I just did a test on my G2 (Android 4.2.2), I launched a broadcast monitor, I switched to the homescreen, and I changed the volume from there.
Apparently, it can detect if the volume is turned up only when it changes from silent mode > to Vibration mode > or to Sound mode. Conversely, when pressing the down volume, I think we can detect the change when it goes from the Sound Mode > to Vibration Mode > or to Silent Mode.
This is probably not what you wanted to hear, but I just wanted to confirm what the others were saying. On a non-rooted phone, what they're saying is mostly correct. On a rooted phone however, there are custom ROMs that have solved this issue.
By the way, what brand/model is your phone? On my phone, when the headset gets connected, the phone lights up. So I suppose, one could always do it the way iPhone owners do it for their phones. You'd have to cut the extremity of a head phone jack, coat half of the pin in plastic, and super glue a button on top of it to allow you to easily twist the head.

Check volume button usage when screen is off

For this question I'm going to quote another user who got no response to their question:
I've written an Andoid app that uses the hardware Volume buttons for another purpose.
It works fine if the app is running and visible, but when I turn the
screen off or let it time out, the button clicks don't get into my
handlers.
Does anyone know if there is a way to detect these button clicks when
the screen is off?
Source: AV695's question
I'm working on an app myself that makes use of the volume buttons, but as this user also noted, the normal behavior of checking buttons with onKeyPress stops working once the screen is off. This is because the Activity gets paused on screen off.
Is there a way to keep the activity running while the screen is off, or check for the usage of the volume buttons when the screen is off? I tried using a Service for this before but it's impossible to check for the volume keys like that as noted by Commonsware.
I doubt that this is supported (without resorting to a battery-draining wakelock) at either the platform, kernel, or underlying radio firmware levels without modifications to the last to bring volume presses during sleep to the attention of the kernel.
Within the realm of reasonable system-ROM modifications, a more reasonable one might be to modify an existing open source ROM for the device to insert some custom platform level code into the handling of the power button usually used to wake up the device preparatory to unlocking it - that at least we know does get the attention of the kernel. That code could then inform the user by sound or vibration if there are unacknowledged notifications.
You could optionally wait briefly, check device orientation, or look for another key press to avoid doing this in an annoying way when the user is holding the device outside their pocket and trying to unlock it.
Or you could not use the volume key and just set a timer to wake up every 15 minutes and vibrate if there are unacknowledged notifications, avoiding the need to fumble in ones pockets.
You mention it's a custom request: if implies it's one off or low-volume, another option to consider would be that a few vendors have "bluetooth watches" out with an SDK that lets you push notifications from an android device.
If you can capture the notification when it's generated, you could push it to the user's wrist, and then let the phone go back to sleep.
You cannot intercept the key while your application is in background, but instead of listening to the KeyPress itself. You can register a ContentObserver, as described in this question.
As Chris Stratton mentioned, the only way to keep your App alive is by using battery-draining wake locks.
However, since I found myself in the same situation, I came up with another solution. Unfortunately, you'll need a rooted device as well as the Xposed framework.
With Xposed, which replaces the zygot process so you can hook yourself into any constructor and method of the system, you will be able to catch the raw KeyEvents before the system handles them.
This is done in PhoneWindowManager.interceptKeyBeforeQueueing(). By using a XC_MethodHook, you can use beforeHookedMethod() on the afore mentioned method to catch every hardware button event, even if the device is in deep sleep.
After catching events you are interested in, you can create a temporary wake lock to do your things but don't forget to release the wake lock after you finished your work.
A good example of how to accomplish this is the Xposed Torch Module.
If you, however, rely on a non rooted system, the bad news is that it's simply not possible without draining the battery...
I was also trying to implement volume button press detection in my app and I left that part to be developed later once the core part is done. I was able to detect volume key press while screen is on even when phone is locked, from a background service.
Background Video Recorder 2 (BVR2) (and possible BVR1 also, I did not try) is one of the apps that can detect volume key press even when screen is off. While trying to implement volume key detection while screen is off in my app, I installed BVR2, hoping to find how it works. To my surprise it gave my app the ablity to detect volume keys even when screen is off. My app had a ContentObserver to monitor volume changes, but was not working when screen is off. When BVR2 is active my app also could detect volume key press when screen is off. Still digging.
But BVR2 has its own trigger action, that is to record video, an action you may not want to occur just for the sake of you application detecting volume key presses.
Another app is QuickClick. This app can give your app what it lacks, the power to detect volume key presses even when screen is off, without extra unwanted actions. Just install QuickClick and do not configure any action. Create a ContentObserver to monitor for stream volume changes and you are ready. You app will now be able to detect volume key presses even when screen is off.
Please note that my app runs as a background service.
Both of the apps mentioned above are meant for other uses, but uses volume key detection to perform action. I am in no way connected to any of the apps mentioned.
If these apps, and possibly dozens others, can detect volume key press, it can be done. I request experts to find out how to do it, so that we can implement in our app without relying on another app.
If you find this answer useful, please up-vote.
I am not sure if it is as simple as this but check this android blog:
Allowing applications to play nice(r) with each other: Handling remote control buttons
It explains the usage of a broadcast receiver that receives the up/down volume controls and other music controls.
In summary you should use registerMediaButtonEventReceiver

Capturing touch events even while system is in sleep

I'm developing an app which requires the system to get the touch events even after the system goes to sleep mode or after the user locks the screen, I tried searching for a solution but it is hard to find one.
Should I want to set any permissions or is there any inbuilt methods or can I override any methods to perform this functionality.
I'm developing an app which requires the system to get the touch events even after the system goes to sleep mode or after the user locks the screen
Fortunately, this is not possible. Otherwise, the device would not be asleep, and battery life would suffer as a result.
Here is a link that shows how to prevent the phone from sleeping.
If you couple that with, say a black screen to 'pretend' the hone is sleeping but actually running your code. So your code can still intercept touch event
Then you need to install your app as a service and make it start when the device is turned on.
You will not need NDK or rooted device for that (sorry, got a short night :) )

How to Stop camera to be used . or how to make it unusable

I am working on an app, in which i need to stop some functionality of phone,
which include :
1) making or receiving phone calls,
2) use of Bluetooth or wifi,
3) Use of camera,
these feature will lock as soon as this app get installed, and will be locked until the get uninstalled, first two i have done, but i dont know how to achieve 3rd task, as i have tried locking the camera with my app, but after some time it automatically unlocked.
any clue/pointer/help will be appreaciated. Thanks
To stop camera usage I would suggest to intercept Intent.ACTION_CAMERA_BUTTON broadcast and just abortBroadcast() - in this case camera usage will be blocked.
The same approach I believe can be used for wifi and bluetooth, though I didn't check it.
Update for sure phone usage can be handled in the same manner.
Try to register broadcast receiver for BOOT_COMPLETE event, and open camera device[s] and lock() it - nobody will be able to use it until lock is given up. And I think it will stay even after your process is killed ( not sure though)
You may also try to FUBAR camera with some weird settings (I managed this sometimes, though can not explain how. - camera was unusable until reboot)

How to determine if the device is idle or if device is plugged in?

I have a service that will be started every once in a while via an AlarmManager.
When it starts I want to be able to check if the device is currently being used or if it is idle.
I could simply check if the screen is on, but it is possible that if the device was charging, or on a dock, that the screen could be on but not being used. So that is is not a perfect method.
Is there a solid way determine that the device is idle?
If not, I figure if the device is plugged in, then in my case I could just carry on as if the device was idle. However, I haven't been able to find a way to check if the phone is plugged in beyond capturing a Broadcast Intent. Is there a way to just check without having to capture the broadcast intents continually?
Android has an in built application called Autolock that can be customized.Please refer these links.
http://www.androidtapp.com/autolock/
http://developer.android.com/guide/practices/design/responsiveness.html
Hope this will help you.

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