Why is there no cancel button in Android's progress dialogs ?

Question

I'm facing the same head-scratching moment similar to what this person (from Jan 2008) experienced when I realize that there is no cancel button in Android's progress dialog or spinners. It is now July 2009 and I've just installed the cupcake version of Android. Has this thing changed ? If not, are you adding a cancel button into the dialogs and how do you do it ?

Answer 1

I'm no Android user or developer, but I think the answer given in the linked-to thread is pretty decent: there's a hardware "back" key on all Android devices. Users are supposed to know to press Back to back out of whatever activity they're currently in.

Thus, the UI designers feel it's unnecessary to include a GUI back/cancel button. This could be viewed as the UI application of the DRY principle; if there's already one way of doing something, that's enough.

Answer 2

The hardware key is the answer here. I'd be careful about generalising the DRY principle to UIs. There are plenty of cases where you need to hammer, hammer, hammer the same point to the user repeatedly via headings, body text, colours and images.

Users dont "read" UIs the way you read a novel. They scan read.

Answer 3

I can't speak for other apps, but in mine anything that might cause the UI thread to wait is executed in a seperate thread. The most I'll do is show a small progress spinner in the titlebar to let the user know something is going on in the background.

Answer 4

not sure about the whole cancel button...i've heard reports of the onCancel() method not firing properly. my solution just consists of making a normal button on the dialog with a call to return whenever the button is pressed.

private void createCancelProgressDialog(String title, String message, String buttonText)
{
    cancelDialog = new ProgressDialog(this);
    cancelDialog.setTitle(title);
    cancelDialog.setMessage(message);
    cancelDialog.setButton(buttonText, new DialogInterface.OnClickListener() 
    {
        public void onClick(DialogInterface dialog, int which) 
        {
            // Use either finish() or return() to either close the activity or just the dialog
            return;
        }
    });
    cancelDialog.show();
}

then just use a simple call method from elsewhere in your activity

createCancelProgressDialog("Loading", "Please wait while activity is loading", "Cancel");

rather simple solution, but it does the trick ;) also just to note that cancelDialog is an activity wipe variable, if you dont need to call it from elsewhere, then you should be able to get away with just limiting the scope of the variable to that method.