--- nav_order: 0036 parent: Decision Records --- # Use TextArea for Chat Message Content ## Context and Problem Statement This decision record concerns the UI component that is used for rendering the content of chat messages. ## Decision Drivers * Looks good (renders Markdown) * User can select and copy text * Has good performance ## Considered Options * Use `TextArea` * Use a [third-party package](https://github.com/JPro-one/jpro-platform) * Use a Markdown parser and convert AST nodes to JavaFX TextFlow elements * Use a Markdown parser to convert content into HTML and use a WebView for one message * Use a Markdown parser and WebView for the whole chat history ## Decision Outcome Chosen option: "Use `TextArea`". All other options require more time to implement. Some of the options do not support text selection and copying, which for now we value more than Markdown rendering. ## Pros and Cons of the Options ### Use TextArea * Good, because it is easy to implement * Good, because it supports text selection and copying * Bad, because it does not offer rich text. Thus, Markdown can only be displayed in a plain text form. * Bad, because default JavaFX's `TextArea` shrinks ### Use a third-party package There seems to be only one package for JavaFX that provides a ready-to-use UI node for Markdown rendering. * Good, because it is easy to implement * Good, because it renders Markdown * Good, because it renders Markdown to JavaFX nodes (does not use a `WebView`) * Good, because complex elements from Markdown are supported (tables, code blocks, etc.) * Bad, because it has very strange issues and architectural flaws with styling * Bad, because it does not support text selection and copying (because of underlying JavaFX `Text` nodes) ### Use a Markdown parser and convert AST nodes to JavaFX TextFlow elements * Good, because we will support Markdown * Good, because no need to write a Markdown parser from scratch * Good, because does not use a WebView * Good, because easy styling * Bad, because we need some time to implement Markdown AST -> JavaFX nodes converter * Bad, because rendering tables and code blocks may be hard * Bad, because it will not support text selection and copying ### Use a Markdown parser to convert content into HTML and use a WebView for one message * Good, because there are libraries to convert Markdown to HTML * Good, because may be easier to implement than other choices (except `TextArea`) * Good, because it supports text selection and copying * Bad, because it may be a problem to connect JavaFX CSS to `WebView` * Bad, because one `WebView` for one message is resourceful ### Use a Markdown parser and WebView for the whole chat history * Good, because there are libraries to convert Markdown to HTML * Good, because it supports text selection and copying * Bad, because it may be a problem to connect JavaFX CSS to `WebView` * Bad, because it may be a problem to correctly communicate with Java code and `WebView` to add new messages ## More Information Actually we used an `ExpandingTextArea` from `GemsFX` package so the content can occupy as much space as it needs in the `ScrollPane`. About the selection and copying, this goes down to fundamental issue from JavaFX. `Text` and `Label` cannot be selected by any means.