Determine if the NavigationDrawer is opening or closing

Question

Is there any way for me to determine whether the navigation drawer is opening or closing? I have read about isDrawerOpen() and isDrawerVisible() methods, but they only return true if the navigation drawer is opened or is visible respectively.

I also read about onDrawerSlide(View drawerView, float slideOffset) method which gets called when the drawer is moving. The slideOffset is the floating value between 0 and 1 telling which position the drawer is at now. But even that gets called when the drawer is opening and closing.

What I need to do is, to do something only when the drawer is opening but not when closing, something tells me that I have to use onDrawerSlide(View drawerView, float slideOffset) method, but I just can't figure out how to check if it is opening and is not closing.

Thank you

Answer 1

To track the last value is an option ...

drawerLayout.setDrawerListener(new DrawerListener() {

        private float last = 0;

        @Override
        public void onDrawerSlide(View arg0, float arg1) {

            boolean opening = arg1>last;
            boolean closing = arg1<last;

            if(opening) {
                Log.i("Drawer","opening");
            } else if(closing) {
                Log.i("Drawer","closing");
            } else {
                Log.i("Drawer","doing nothing");
            }

            last = arg1;
        }

        @Override public void onDrawerStateChanged(int arg0) {}
        @Override public void onDrawerOpened(View arg0) {}
        @Override public void onDrawerClosed(View arg0) {}

    });