JSQMessagesViewController can't find heightForCellTopLabelAtIndexPath

Question

as my questions already says: I am currently implementing the JSQMessagesViewController component in Xamarin.iOS and everything works fine for now, but for some reason I can not find the heightForCellTopLabelAtIndexPath method as described at this link . All the other methods are visible to me, even the one that returns the attributed text for the top cell label.

Thanks for the help!

Answer 1

Wow I did not even know that you could use this library in Xamarin apps but also I don't do anything in Xamarin but that is super cool. Well as per your question. I was not able to see that method either so maybe the documentation is off but to use:

 override func collectionView(_ collectionView: JSQMessagesCollectionView!, layout collectionViewLayout: JSQMessagesCollectionViewFlowLayout!, heightForMessageBubbleTopLabelAt indexPath: IndexPath!) -> CGFloat {
    return firstMessageInSet(indexOfMessage: indexPath) ? 0 : kJSQMessagesCollectionViewCellLabelHeightDefault
} 

The only difference is that it is referencing the messageBubbleTopLabel and not the CellTopLabel per say. I think that is the correct method to use.

In the screen shot provided I show how this effects the look of the messages. The first message has the size set to kJSQMessagesCollectionViewCellLabelHeightDefault and the message fallowing it has it set to 0

So if that is what you are trying to achieve then this is the method for you. 🤓 if not, let me know and I will see if there is something else that we can do.

Keep up the good work. 🖖🏽

Answer 2

I think you are looking for GetMessageBubbleTopLabelHeight !

I'm not aware of any Xamarin oriented doc for this lib, but I'll gladly give you an example usage =)

This is how i used the function :

public override nfloat GetMessageBubbleTopLabelHeight (MessagesCollectionView collectionView, MessagesCollectionViewFlowLayout collectionViewLayout, NSIndexPath indexPath)
    {
        Message message = Messages [indexPath.Row];

        if (message.SenderId == Sender.UserId.ToString())
            return 0.0f;

        if (indexPath.Row - 1 >= 0) {
            Message previousMessage = Messages [indexPath.Row - 1];
            if (previousMessage.SenderId == message.SenderId)
                return 0.0f;
        }
        return 20.0f;
    }

Answer 3

In the end I just used the GetCellTopLabelAttributedText and modified it to fit my use case. In other words I central aligned the text, deleted the contentInset and changed the font. I gave up looking for the method that was missing