How to mark line numbers in javascript ace editor?

Question

As you can see in the following screenshot:

Ace editors have a 'gutter' on the left-hand side that contains the line numbers. I would like to detect a click on this gutter and insert a marker for a breakpoint, as in the following screenshot from chrome dev tools

I've had a look at the Ace editor API, but can't figure out how to do it, could someone tell me the best way to go about it?

Thanks

Answer 1

See this thread https://groups.google.com/d/msg/ace-discuss/sfGv4tRWZdY/ca1LuolbLnAJ

you can use this function

editor.on("guttermousedown", function(e) {
    var target = e.domEvent.target; 
    if (target.className.indexOf("ace_gutter-cell") == -1)
        return; 
    if (!editor.isFocused()) 
        return; 
    if (e.clientX > 25 + target.getBoundingClientRect().left) 
        return; 

    var row = e.getDocumentPosition().row;
    e.editor.session.setBreakpoint(row);
    e.stop();
})

and don't forget to add some styling for breakpoints e.g.

.ace_gutter-cell.ace_breakpoint{ 
    border-radius: 20px 0px 0px 20px; 
    box-shadow: 0px 0px 1px 1px red inset; 
}

Breakpoints are often toggled. To achieve this behavior, use

...

var breakpoints = e.editor.session.getBreakpoints(row, 0);
var row = e.getDocumentPosition().row;
if(typeof breakpoints[row] === typeof undefined)
    e.editor.session.setBreakpoint(row);
else
    e.editor.session.clearBreakpoint(row);

...

Notice the strange use of EditSession.getBreakpoints(), which doesn't return an array of row numbers as documentation suggests, but rather an array with indices corresponding to the row numbers.