Develop Reference

Cancel Touch Eventbutt

I am writing an very simple application with following scenario:
1) Screen A have 3 button to move on other screen's.
2) Now if I hold one button(say Button 1) and perform rapid click on other button then it launch multiple instance of other screen. Which I think should not be happened. How can prevent this.
3) and it's more weird. After move on other screen if I don't release Button 1 which was on Screen A then it still allow to perform click for rest of two button of screen A even I can see second screen.
Here it's clear launch second screen but still first screen button event working.
Any idea how can avoid such scenario.

How you are going to disable other buttons while having 1 enabled, that's an algorhytmic problem. You can try creating a boolean or control variable in your activity (and then pass the final reference of the activity to wherever you need it), or in a static context. But to answer the title of the question - you can "Cancel Touch Event" either by adding an OnTouchListener, or if you're extending class Button, you can override onTouchEvent(MotionEvent ev) method.
Using OnTouchListener will disable any previously defined touch-event behavior. You can call the actual click event from the inside by calling performClick method from your button.
//in order to use button inside OnTouchEvent, its reference must be final
//if it's not, create a new final reference to your button, like this:
final finalButton = button;
button.setOnTouchListener(new OnTouchListener() {
#Override
public boolean onTouchEvent(MotionEvent ev) {
// ... additional code if necessary
if(canBeClicked) {
finalButton.performClick();
return true;
}
else return false;
}
}
Overriding onTouchEvent in a class extending Button should look something like this.
#Override
public boolean onTouchEvent(MotionEvent ev) {
// ... additional code if necessary
//here we don't really need to call performClick(), although API recommends it
//we just send the touch event to the super-class and let it handle the situation.
if(activity.canBeClicked) return super.onTouchEvent(ev);
else return false;
}

One solution that I found is to disable click listener in onPause() and enable it in onResume() . Can we have better support for this?

Automatic Android Click/Tap tracking

Is there a clever way to "do something" every time a user clicks or taps on the screen? I'd like to know which view they tapped on, and do it without having to replace all my standard views with custom views.
Basically, I want to add click tracking in my app to help with analytics. We already have page tracking (by using a shared superclass for every activity), but in some cases page tracking isn't enough and we actually want to track clicks.
How can I execute a function every time the user clicks on a View on the screen?

In each of your Activities, just add this at the end of onCreate (this is especially easy if all your Activities are subclasses of a custom Activity, because then you only need to write this once):
getWindow().getDecorView().findViewById(android.R.id.content).setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent e) {
//handle your code here
return false;//don't absorb the touch.
}
});
Edit
The above code does not allow easy recognition of which Views are touched. The below code will. Note that this may break other onTouchListeners if the View in question already has registered an onTouch event. If not, this will work great. It uses the droidQuery library to select all views in the hierarchy and set uses code like above to handle touches without absorbing the event. The best place for this would be at the end of onCreate, in every Activity:
First, select the highest level of the architecture you want. If your layout's root view has an id, that would be the best thing:
$.with(this, R.id.root_id)
If not, either add one, or select the topmost view (above your layout). Note that for analytics this may provide some results you do not need:
$.with(this).selectAll()
Now, on the end of this selection, append the following:
.each(new Function() {
#Override
public void invoke($ d, Object... args) {
d.view(0).setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent e) {
//do something with the clicked view, such as:
handleTouch(v, e);
return false;//don't absorb the touch.
}
})
}
});
Then have a new method:
private void handleTouch(View v, MotionEvent e) {
//handle the view touch.
}

Android custom keyboard in webview

I'm trying to implement a custom keyboard in Android. I want to input some text in my Webview. Since I don't want to display the keyboard when I hit everywhere in the Webview I was thinking of a listener of something like this:
webview.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
if (((WebView) v).getHitTestResult().getType() == EDIT_TEXT_TYPE)
showMyKeyboardHere();
return false;
}
});
is my listener, it seems to return EDIT_TEXT_TYPE on the key press I do AFTER I've pressed the edit text field. So when I press the edit text field it returns UNKNOWN_TYPE and the click after that when pressed somewhere else returns EDIT_TEXT_TYPE. My guess would be that the OnTouchListener happens before the touch even gets sent on to the Webview it won't have registered it. Any way to change that?
Now to my question: Since I will only want my custom keyboard in this application, is there anyway to listen to whatever event is called to bring up the normal keyboard and immediately hide it and show my own?

How can I get all of touch events in my activity even in drag mode?

I want to get x and y position of every touch point in my activity even in drag mode. When I implement onTouchEvent method of my activity, it does not get all of touch events. How can I do that?
Thanks in advance,
public class MyActivity extends Activity {
#Override
public boolean onTouchEvent(MotionEvent event) {
// my Code
return super.onTouchEvent(event);
}
}
This onTouchEvent method just rises when you touch around the activity.

Do you have any other View which handle touch events?
The documentation says:
Called when a touch screen event was not handled by any of the views
under it. This is most useful to process touch events that happen
outside of your window bounds, where there is no view to receive it.
So when you say you don't get any events when you are in drag mode, this implies that you're dragging some thing. So you already handling the events somewhere else and therefore the onTouchEvent() method won't be notified.
You can try to return false in the other TouchListener's onTouch() method so the event will bubble up further more.

android touch tracking

I have a Main activiy, and many other activity that extends main activity. I want to track all touch events like clicking button, listview item, textView..etc in child activities .But i was unable to do that.I Implemented onTouchEvent(MotionEvent event) in main activity,
#Override
onTouchEvent(MotionEvent event)
public boolean onTouchEvent(MotionEvent event) {
System.out.println("onTouchEvent pressed");
return super.onTouchEvent(event);
}
But This function was not called.. any ideas?

Take a look at https://github.com/commonsguy/cw-advandroid/blob/master/Tapjacking/Jackalope/src/com/commonsware/android/tj/jackalope/Tapjacker.java.
It is a service that adds a transparent View to the window manager. The service also implements a onTouchListener. The listener will track all touch events while the app is running.
It is probably the easiest to implement and provides a central place to track touch events.