JXA set window bounds weird issue - applescript

Question

script1.js:
function run() {
const chromeApp = Application('Google Chrome');
const window = chromeApp.windows[0];
console.log(window.name());
window.bounds = {
x: 0,
y: 0,
width: 500,
height: 500,
};
chromeApp.activate();
}
Run:
osascript -l JavaScript script1.js
And it works
script2.js:
function run() {
const systemEvents = Application('System Events');
const ap = systemEvents.processes().find(ap => ap.name() === 'Google Chrome');
console.log(ap.name());
const window = ap.windows[0];
console.log(window.name());
window.bounds = {
x: 0,
y: 0,
width: 500,
height: 500,
};
}
Run:
osascript -l JavaScript script1.js
It does NOT work:
script2.js: execution error: Error: Error: Can't set that. (-10006)
But I really need to get script2.js work. Because in my real application, I don't know the application name in advance and I need to fetch the process dynamically base on user interaction. Because I don't know application name, I cannot use script1.js.
Any input is appreciate!

Answer 1

function run() {
const systemEvents = Application('System Events');
const p = systemEvents.processes().find(ap => ap.frontmost() === true);
const ap = Application (p.bundleIdentifier());
const window = ap.windows[0];
window.bounds = {
x: 0,
y: 0,
width: 500,
height: 500,
};
}

Answer 2

It’s years since I’ve had the displeasure of using GUI Scripting so didn’t immediately spot the real problem.
The real problem is that System Events is a bloated badly designed mess that shoehorns a dozen libraries’ worth of functionality into one #BigBallOfMud.
SE includes Cocoa Scripting’s Standard Suite window class definition, including a standard bounds property, but doesn’t actually implement it (since SE has no windows of its own). So while SE’s dictionary claims windows elements have a bounds property, trying to get/set that property throws an error. It is very confusing.
Therefore, ignore the window class definition in SE’s Standard Suite, and only look at the window class definition in its Process Suite (aka GUI Scripting). It doesn’t have a bounds property; instead it has separate position and size properties:
position (list of number or missing value) : the position of the window
size (list of number or missing value) : the size of the window
Here is code that works:
tell application "System Events"
set ap to first process whose name is "Firefox"
set win to window 1 of ap
-- set bounds of win to {100, 100, 600, 600} -- this doesn't actually work
set position of win to {100, 100}
set size of win to {500, 500}
end tell
In other words, just because an app’s dictionary says it supports something doesn’t mean it actually does. Trying to figure out an app’s brokenness while also wrestling with JXA’s brokenness is at best a Sisyphean’ exercise.
Figure out how you get your code working in AppleScript first; if it doesn’t work there then you know it’s the app that’s the problem. If you still want to use JXA, then you can attempt to port your working code to that afterwards (although generally I don’t recommend wasting time on JXA as it’s crippled and abandoned, and the whole AppleScript stack is slowly dying anyway).

Answer 3

Inspired by Robert's answer, I found that the following works:
function run() {
const systemEvents = Application('System Events');
const p = systemEvents.processes().find(ap => ap.name() === 'Google Chrome');
console.log(p.name());
const app = Application(p.name());
const window = app.windows[0];
window.bounds = {
x: 0,
y: 0,
width: 500,
height: 500,
};
app.activate();
}
So I can convert a Process into Application by name: const app = Application(p.name()); Then script2.js become script1.js.
But it doesn't always work. For example, the following doesn't work:
function run() {
const systemEvents = Application('System Events');
const p = systemEvents.processes().find(ap => ap.frontmost() === true);
console.log(p.name());
const app = Application(p.name());
const window = app.windows[0];
window.bounds = {
x: 0,
y: 0,
width: 500,
height: 500,
};
app.activate();
}
If the frontmost application is Visual Studio Code. Because the process name will be "Electron" and convert process to application will be wrong.
I'd like to find a way to convert process to application by ID. I am still investigating and I will post updates later.
Update: please check the accepted answer.

Answer 4

You can set the position and size to a two-dimensional array. Because Application("Name of App") doesn't always seem to work, it's best to go through System Events.
let sys = Application("System Events")
let app = sys.applicationProcesses
.whose({ name: "AppYouWant"})[0]
app[0].windows[0].size = [200, 200]
app[0].windows[0].position = [200, 200]