Click on a specific place on a window, click on a specific button and control if the window changes - window

Question

Actually I have 3 questions about the same problem: controlling a window with applescript.
What should I do if I would press on button "Close Window" of application "Google Chrome"?
Is it possible to check if the window changes? For example, to see if appear a pop-up or something like that...
What about clicking on a specific place into a window? I mean, I know I can use
tell application "System Events"
click at {x,y}
end tell
but this command use the entire screen as reference system, and I want it works only on a specific window. For example, if at "{x,y}" i put "{1,1}", applescript will click on the first item on the menu bar. Is there a way I can say to "System Events" to click at "{1,1}", but on the window "Google Chrome"?

Answer 1

Here are three examples of how to close the front window of Google Chrome using AppleScript:
Note: The following assumes Google Chrome is running with at least one window open when you test each example AppleScript code in Script Editor.
Example one is the most straight forward way:
tell application "Google Chrome" to close front window
Example two directly clicks the close button:
tell application "System Events" to tell ¬
application process "Google Chrome" to ¬
click button 1 of front window
Example three calculates the center of the close button and clicks there:
activate application "Google Chrome"
delay 0.5
tell application "System Events" to tell ¬
application process "Google Chrome" to tell ¬
front window
set posB1 to (position of button 1)
set szB1 to (size of button 1)
set x to (item 1 of posB1) + (item 1 of szB1) / 2 as integer
set y to (item 2 of posB1) + (item 2 of szB1) / 2 as integer
end tell
tell application "System Events" to click at {x, y}
Note that in the first two examples, the front window of Google Chrome doesn't even need to be the frontmost window on the Desktop; however, with the third example it does, otherwise the click at {x, y} will not go to the intended target.
That said, example three really shouldn't be used when there it a straight forward way, as in example one, to get the job done. Example three was just a proof of concept to get the coordinates to click at. This method may be useful in some fringe cases, especially in an app that doesn't directly support AppleScript.
Note: The example AppleScript code is just that and does not contain any error handling as may be appropriate. The onus is upon the user to add any error handling as may be appropriate, needed or wanted. Have a look at the try statement and error statement in the AppleScript Language Guide. See also, Working with Errors.

Answer 2

In applescript GUI scripting you can simply refer to an element by name or index and tell it to click or to perform an action. For instance to click the close button on the first open window in Chrome you could use:
tell application "System Events"
tell process "Google Chrome"
tell window 1
tell button 1
click
end tell
end tell
end tell
end tell
You don't actually need to know its physical position to click one it; you just need to know that the first button in the window is the close button.
System Events always returns the position of any element in screen pixels, so if you want the position of an element in terms of its window, get the position of the element, get the position of the window, and do some addition or subtraction (e.g., if you want to click at {5,5} in a window whose position is {100, 125}, click at {105, 130})
AppleScript isn't really designed to monitor GUI changes, though if you want to be tricky and you know what change you're looking for you can do something like this:
tell application "System Events"
tell process "..."
tell window 1's pop up button 3
repeat until (exists menu 1)
delay 0.2
end repeat
-- menu 1 now exists, so the pop up button is open
end tell
end tell
end tell
...but note that this will hang the script until the menu is opened. A more elegant way to handle that is to write a script application with an idle handler, like so:
on run
-- whatever initialization is needed
end run
on idle
tell application "System Events"
try
tell process "..."
tell window 1's pop up button 3
if exists menu 1 then
-- menu 1 now exists
-- the pop up button is open
-- do what must be done
end if
end tell
end tell
on error errstr
display alert "Something went wrong" message "The script sent this error: " & errstr
end try
end tell
return 0.2
end idle
You can leave that running in the background watching for specific changes in the GUI (the 'try' statement is in case the app you're watching quits, the window closes, or something unexpected happens to the GUI).
If you haven't already, open the System Events scripting definition in Script Editor and look at the Processes Suite. That will show you all the things you can do with GUI scripting.