Develop Reference

Disable volume up/down to open camera

I have an app using firebase scanning to scan barcodes. I want to disable the use of volume up/down to open the scanner/camera. I also want the user to be able to still change the volume using those button.
I tried overwriting the onKeyDown event on my base activity but it doesn't fix my issue.
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN || keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
return false;
} else {
return super.onKeyDown(keyCode, event);
}
}

Why does my webview finish unexpectedly?

I place a fragment with a webview widget to load my webpages and create a host fragmentActivity as my webpages' container. Now that there is a page, including a media player, seems like to support various of content for us. Here comes the problem, if I click the play button, the media player works well itself, however, when i adjust the power of volume, either higher or lower, the host activity finish unexpectedly. Complementally, I just handle the back event in the method of onKeyEvent.
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK) {
if(webview.canGoBack()){
webview.goBack();
return true;
}
}
return super.onKeyDown(keyCode, event);
}
Anybody helps me?

How to control android media volume using volume keys

Can anyone provide sample code for adjusting media volume using volume keys, and also it should display a volume alert progress while pressing the keys.

I think you want this.
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN || keyCode == KeyEvent.KEYCODE_VOLUME_UP) {
// Do your thing
return true;
} else {
return super.onKeyDown(keyCode, event);
}
}

Volume preference - blocking volume keys

I have seen couple of similar problems with solutions, but I couldn't find one that would work in my situation.
I am making VolumePreference (extending DialogPreference) that let's user choose volume level for some alarm.
In other preference user chooses desired ringtone that is played during alarm. It is also played while user is choosing volume in VolumePreference, so he knows how it actually sounds.
In yet another preference user chooses if alarm should "override" phone's media volume level when playing - I do that, so if user wants to have fixed volume level for alarm, then it shouldn't be affected by changes made by volume keys and so on.
If user chooses to do that, before starting to play alarm in AlarmActivity, I set volume to max level with AudioManager and intercept all keyDown events of volume keys, restoring volume level after alarm finishes.
Problem is, I can't block volume keys within my VolumePreference as there is no onKeyDown method.
After some checking, I found registerMediaButtonEventReceiver method of AudioManager that "Register a component to be the sole receiver of MEDIA_BUTTON intents.", which I believe could help in my situation (making some empty receiver), and even make volume locking more universal (register when I want to start lock, unregister after unlock), but it is working from API8, while I am making app for API7 - which still hold over 10% of market from what I read, so I would like to stick to it.
Any ideas on how one could block volume changes in PreferenceDialog?

After some thinking solution proved to be really simple - one can override onKeyDown method of View created in onCreateDialogView of DialogPreference or set onKeyListener of that View.
First example:
LinearLayout layout = new LinearLayout(mContext)
{
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN
|| keyCode == KeyEvent.KEYCODE_VOLUME_UP) return true;
return super.onKeyDown(keyCode, event);
}
#Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN
|| keyCode == KeyEvent.KEYCODE_VOLUME_UP) return true;
return super.onKeyUp(keyCode, event);
}
};
Second example (mDialogView is saved reference to layout from first example):
mDialogView.setOnKeyListener(new View.OnKeyListener() {
#Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN
|| keyCode == KeyEvent.KEYCODE_VOLUME_UP)
return true;
return false;
}
});
I have chosen second solution, as I think it is more flexible for two reasons at least
I can just remove listener to stop blocking volume keys, while in first method I can't
in first solution I need to decide if I want to block keys input while creating View - not much use if VolumePreference is extending some other Preference that shouldn't block keys input

Trying to catch the Volume onKeyLongPress() not working

I'm trying to get my app to react to a long key press on volume down with the following code:
public boolean onKeyLongPress(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
Log.w("myApp", "LONG PRESS");
}
return super.onKeyLongPress(keyCode, event);
}
However, it only spams a bunch of onKeyPress() events for volume down, and onKeyLongPress() never gets called. My intention is to leave the volume down and up "short" presses alone, and have my app react differently to the volume long press.
Can anybody point out what I'm missing?

You are almost there. You need to detect the same key event in the onKeyPress handler and start tracking it so that the long press can work. Here's the code you need:
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_VOLUME_DOWN) {
event.startTracking();
return true;
}
return super.onKeyDown(keyCode, event);
}