如何处理GridView中同一项目上的onItemClickListener和OnTOuchListener？

Question

First, I would like to apologize for my English. That's not my native language.

I have a simple gallery in Android. Images are loaded in GridView . I have problem with onItemClickListener and onTouchListener . I have set onItemClickListener for GridView and onTouchListener for childs of GridView ( ImageViews ). When I click on the image, it should be shown on the center of phone screen and when I press it, it should zoom-in on the place where my finger was and when I release my finger, it should zoom-out.

The problem is that when is set onTouchListener , only it is fired. I would like to recognize when I clicked and when I pressed-released.

Thank you for your help.

Answer 1

you are looking for checking the value of event.getAction() which returns MotionEvent constant:

gridView.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                //Do something when user touch the screen 
                //(first touch event-before moving or releasing the finger)
                break;
            case MotionEvent.ACTION_UP:
                //Do something when user release the finger touching the screen.
                break;
            }
            return false;
        }
    });

You also have ACTION_MOVE which exist when user move his finger before he released it from the screen (good for dragging etc...)

EDIT:

The problem with onTouch() is that it only exist for the entire view (Your grid) and you don't have onItemTouch() . One solution will be to get the info you need from the item when onItemClick() happens into a class defined variable (For example the Bitmap of the picture you clicked on) and then use it to whatever you need in the onTouch() event. Remember in onTouch() if your return true at any point it means you already dealt with the touch case and onClick() won't happen. Also - on click calls ONLY when releasing the finger from the screen (means MotionEvent.ACTION_UP ) so you won't have it on the touch event.

To solve this you need to either use onItemLongClick() instead, or set onTouchListener for each of the items in the grid with custom adapter (in getView() ).