StreamMessageWidget

A Widget For Displaying Messages And Attachments

Find the pub.dev documentation here

Background

There are several things that need to be displayed with text in a message in a modern messaging app: attachments, highlights if the message is pinned, user avatars of the sender, etc.

To encapsulate all of this functionality into one widget, the Flutter SDK contains a StreamMessageWidget widget which provides these out of the box.

Basic Example (Modifying StreamMessageWidget in StreamMessageListView)

Primarily, the StreamMessageWidget is used in the StreamMessageListView. To customize only a few properties of the StreamMessageWidget without supplying all other properties, the messageBuilder builder supplies a default implementation of the widget for us to modify.

class ChannelPage extends StatelessWidget {
  const ChannelPage({
    Key key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: StreamMessageListView(
        messageBuilder: (context, details, messageList, defaultMessageWidget) {
           return defaultMessageWidget.copyWith(
             showThreadReplyIndicator: false,
           );
        },
      ),
    );
  }
}

Building A Custom Attachment

When a custom attachment type (location, audio, etc.) is sent, the MessageWidget also needs to know how to build it. For this purpose, we can use the customAttachmentBuilders parameter.

As an example, if a message has a attachment type 'location', we do:

StreamMessageWidget(
    //...
    customAttachmentBuilders: {
        'location': (context, message, attachments) {
            var attachmentWidget = Image.network(
              _buildMapAttachment(
                attachments[0].extraData['latitude'],
                attachments[0].extraData['longitude'],
              ),
            );

        return wrapAttachmentWidget(context, attachmentWidget, null, true, BorderRadius.circular(8.0));
    }
  },
)

You can also override the builder for existing attachment types like image and video.

Show User Avatar For Messages

You can decide to show, hide, or remove user avatars of the sender of the message. To do this, set the showUserAvatar property like this:

StreamMessageWidget(
    //...
    showUserAvatar = DisplayWidget.show,
)

Reverse the message

In most cases, StreamMessageWidget needs to be a different orientation depending upon if the sender is the user or someone else.

For this, we use the reverse parameter to change the orientation of the message:

StreamMessageWidget(
    //...
    reverse = true,
)