Element Focus

[karai17]

The GUI instance needs to be aware which element currently has focus.

Each element needs the following functions:

• focus(bool)
  • Set this element to have input focus
  • Call the on_focus callback
• has_focus()
  • return whether or not this element has focus

function Element:focus(f)
    local focus = self:has_focus()
    if focus and not f then
        gui:set_focus(false)
    elseif not focus and f then
        gui:set_focus(self)
    end
end

function Element:has_focus()
    return gui._focus == self
end

I suppose for this to work, each element is going to need a handle of the GUI instance it belongs to!

[karai17]

Alright, this is in now.