hs.alert.show: how to place this alert on different place on screen (center?)

[muescha]

How can I position the 'hs.alert.show' alert at a different location on the screen?

I'd prefer to have it centered within a child window of an app that's not in full-screen mode.

[latenitefilms]

There's no way to change position (aside from choosing a screen) currently in the extension, but the extension is all Lua, so you could copy and modify as needed:

hammerspoon/extensions/alert/alert.lua

Line 78 in 0ccc9d0

local showAlert = function(message, image, style, screenObj, duration)

[muescha]

thanks for the hint. i tried to fake an screen object from a window object to get it to the alert as "Screenobject" - the only thing missing was the :fullFrame()

hammerspoon/extensions/alert/alert.lua

Line 103 in 0ccc9d0

local screenFrame = screenObj:fullFrame()

but this patch from chat gpt not working :(

	local win = hs.window.focusedWindow()
	local extendedWindowMetatable = {
        __index = {
            fullFrame = function(self)
                return self:frame()
            end
        }
    }

    setmetatable(win, extendedWindowMetatable)

	hs.alert.show("Hello World!", win)

i have done it with this patch in alert.lua:

-   local screenFrame = screenObj:fullFrame()
+   local screenFrame = screenObj.frame and screenObj:frame() or screenObj:fullFrame()

muescha/dot_hammerspoon@7a95c28

now i can call it with

	hs.alert.show("Hello World!", win)

[muescha]

one idea was to allow a hs.geomety object as parameter, but this was not possible to test with getmetatable(frame) == hs.getObjectMetatable('hs.geometry')

[muescha]

a little bug: :frame() exists also on the screen so I have to test for .allFrame:

-   local screenFrame = screenObj.frame and screenObj:frame() or screenObj:fullFrame()
+   local screenFrame = screenObj.fullFrame and screenObj:fullFrame() or screenObj:frame()

[muescha]

opened:

• Update alert.lua: allow window object as parameter Update alert.lua: allow window object as parameter #3542

[cmsj]

PR is merged, so I'm going to close this.

[Rhys-T]

one idea was to allow a hs.geomety object as parameter, but this was not possible to test with getmetatable(frame) == hs.getObjectMetatable('hs.geometry')

For what it's worth: hs.getObjectMetatable seems to only work for modules that put their metatables into the registry, which currently means just the ones that are implemented in native code/Objective-C. hs.geometry is written in pure Lua and doesn't register itself, so hs.getObjectMetatable('hs.geometry') just returns nil. However, hs.geometry actually uses the module itself as the metatable, so you can instead do getmetatable(frame) == hs.geometry. I don't know if that fact is considered 'public API' though, so if you'd prefer, you can do:

local geometryMT = getmetatable(hs.geometry '0x0')
if getmetatable(frame) == geometryMT then
	-- …
end

[asmagill]

FWIW, lua only code can add its metatable to the registry so hs.getObjectMetatable works with the following code:

debug.getregistry()[userdata_tag] = metatable

Then, hs.getObjectMetatable(userdata_tag) will work; it also means that we can assign the metatable from C/Swift side code, even though the metatable is pure lua code.