Snackbar: how to identify which snackbar is shown

Question

I have a recyclerview which implements the swipetorefresh layout - if you swipe your finger down the list, it will load newer posts. It also has a onloadmorelistener which serves to paginate my recyclerview - if you swipe your finger up the recyclerview, it will load older posts.

I'm trying to build in a snackbar notification where if the user is offline and he tries to complete some type of network activity, like loading old or new posts, the snackbar will appear telling him that there is "No internet".

In the case where there is no internet and the user swipes up and swipes down on the recyclerview, two snackbar notification displaying the same "No internet" message is shown. I actually just want one to be shown instead.

Therefore, I'm looking for some unique way to identify the text which is shown in the snackbar so that if the text is the same in both snackbar, only one snackbar gets displayed but there is no getText() method in snackbar and there is only setText(): http://developer.android.com/intl/es/reference/android/support/design/widget/Snackbar.html

I also see that there are callback methods: http://developer.android.com/intl/es/reference/android/support/design/widget/Snackbar.Callback.html but none of which seems to help in my scenario.

I wish there was a unique flag that I could have given to the snackbar when it was created for identification purposes but the Snackbar.make method doesn't allow so.

Has anyone been successful in solving an issue similar to this?

Answer 1

Use the snackbar callback. when it's shown add it to a list for example , then when the callback is called , remove it , so you have only still visible snackbars. example of callback :

snackbar.setCallback(new Snackbar.Callback() {

    @Override
    public void onDismissed(Snackbar snackbar, int event) {
      //see Snackbar.Callback docs for event details
      ...  
    }

    @Override
    public void onShown(Snackbar snackbar) {
       ...
    }
  });

Answer 2

I'll try to put what Helmi said on code

private Map<String, String> snackbarList = new HashMap<>();
private CoordinatorLayout mCoordinatorLayout;

private void displaySnackbarIfNotShown(String snackbarText) {
    //Check if the snackbar is already on the list
    if(snackbarList.containsKey(snackbarText)){
        //Snackbar already exist, you may update its text or ignore it
    } else {
        Snackbar mySnackbar = Snackbar.make(mCoordinatorLayout, R.string.prompt_adjust_map,
                                            Snackbar.LENGTH_INDEFINITE);

        mySnackbar.setCallback(new Snackbar.Callback() {
            @Override
            public void onDismissed(Snackbar snackbar, int event) {
                //Remove from the snackbar list
                snackbarList.remove(snackbarText);
            }

            @Override
            public void onShown(Snackbar snackbar) {
                //Add to the snackbar list
                snackbarList.put(snackbarText, "");
            }
        });
        mySnackbar.show(); 
    }
}