feature: Able to match newline in onTextInput handler

When implementing heading (H1, H2, H3) in WYSIWYG markdown editor, it would requires detecting if newline is entered. So I can do something like this:

editor.onTextInput({
  // "# " -> h1, "## " -> h2, "### " -> h3
  match: /^(#{1,3})(.*)\n/,
  run() {
    // magic happens here
  }
});

Is this possible in current structure?

[eguitarz]

@bantic That sounds perfect to me! I’ll work on this - Add willHandleNewline hook prior to handleNewLine and will stop handling new line if willHandleNewline returns explicit false (It works as default if willHandleNewline didn’t return or it returns true).

[bantic]

I believe this is closed by #489. thanks @eguitarz ! Feel free to reopen if necessary.