如何在视图上禁用触摸事件？

Question

My (OpenGL ES 2.0) app has a splashscreen which is basically an Android View displayed over my GLSurfaceView .

I do all my initial setup on an AsyncTask and then (out of necessity), load my bitmaps/textures on the GLRendering thread in onSurfaceCreated. Once everything has loaded, I dismiss my splashscreen.

Everything works as expected apart from one thing. The splashscreen still accepts input and if the screen is touched just after the app is launched, I (obviously) get an null pointer exception.

I simply create my view like so:

splashscreen = new SplashScreen(getApplication(), width, height);  //Where SplashScreen is a custom class that extends View

I then add it to my layout like so:

layout.add(myView);        //My GLSurfaceView
layout.add(splashscreen);  //The splashscreen View
setContectView(layout);

Once everything has loaded, I simply remove the (splashscreen) View to reveal my GLSurfaceView underneath:

layout.removeView(splashscreen);
splashscreen=null;  //Null it

currently, in my onTouch method, to get around the issue, I have put a check in place like so:

public boolean onTouchEvent(MotionEvent event) {

    if(splashscreen==null){
    //Do touch related stuff here
    }

    return true;

}

This does work, however, I'm sure it's not the cleanest way to achieve what I'm after.

I've tried this:

splashscreensetClickable(false);

and

layout.setClickable(false);

as well as setEnabled(false)

Nothing seems to work, but I'm sure there must be a way of doing this.......

Answer 1

Generally, you will want the splash screen to prevent the user from doing anything while it is present. You can actually do this, because views in android, as in other UI frameworks, have a hierarchy in which touch events cascade.

Even though you don't want the splash screen to be interactive, you can still steal all of the touch events that occur on it, and just do nothing with them. The answer itself is to override onTouchEvent in your SplashScreen class with:

@Override
public boolean onTouchEvent(MotionEvent event) {
    return true; // Splash screen is consuming all touch events on it.
}

Returning true in this basically says that nothing under this view should receive a touch event. As long as it is visible and over top of the surface view, your surface view will not get any touch events. See here for details.