CODEWITHSUNDEEP
androidmenuonclicklistenerandroid-alertdialog
Bóg Programowania
Bóg Programowania

Reputation: 63

Android AlertDialog.Builder - good OnClickListener item id practice?

Suppose I want to create a simple dialog using AlertDialog.Builder. Is there any nice way to get rid of written "by hand" comparison to integers in it's OnClickListener?

I can make some constants, but it still is something that has to be changed in 2 places, if somebody adds another item to menu.

final CharSequence[] menuOptions = new CharSequence[]{"one","two","three"};
AlertDialog.Builder builder = new AlertDialog.Builder(MapBrowsingActivity.this);
builder.setTitle("Choose action").
        setItems(menuOptions, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                if (which == 0) {
                    //do sth;
                }
                if (which == 1) {
                    //do sth;
                }
                if (which == 2) {
                    //do sth;
                }
            }
        });
builder.create().show();

Upvotes: 0

Views: 287

Answers (2)

tynn
tynn

Reputation: 39863

You cannot really do anything about it. If somebody changes the menu items, also the handling should be changed. You could use a switch to make it a little clearer though:

switch(what) {
    case 0:
        //do sth;
        break;

    case 1:
        //do sth;
        break;

    case 2:
        //do sth;
        break;

    default:
        throw new RuntimeException("item unknown");
}

Upvotes: 1

gio
gio

Reputation: 5020

You can use next approach which is based on usage of enum. It requires additional stuff with converting enum to CharSequence, but guarantees that when you or another developer will add/remove/insert new menu app would work ok.

private void showMenu() {
    final Menu[] values = Menu.values();
    CharSequence[] items = new CharSequence[values.length];
    for (int i = 0; i < values.length; i++) {
        items[i] = values[i].toString();
    }
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle("Choose action").
            setItems(items, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    Menu value = values[which];
                    switch (value) {
                        case Menu1:
                            break;
                        case Menu2:
                            break;
                        case Menu3:
                            break;
                    }
                }
            });
    builder.create().show();
}

private enum Menu {
    Menu1,
    Menu2,
    Menu3
}

Upvotes: 3

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