topic Re: Center non-modal window on display in Discussions

Center non-modal window on display

mringqui — Fri, 09 Jun 2023 16:59:09 GMT

Hi, I am trying to find the fastest way to move a window to the center of the users display.

Modal windows automatically are centered on the screen, so I know that JMP is somehow able to tell where to put a window, but I have only found some relatively slow workarounds to doing this with non-modal windows. Below is the jsl script I am currently using to determine the screen size and center a new window.

Is there a faster way? Thanks!

win2 = NewWindow("Test Window");
winSize = win2  << GetWindowSize();
win2  << ShowWindow(0);

testwin = NewWindow("test", << ShowWindow(0));
testwin << Maximize Window(1);
dispsize = testwin << Get Window Size;
testwin << CloseWindow();


win2 << MoveWindow(dispsize[1]/2 - winsize[1]/2, dispsize[2]/2 - winsize[2]/2);
win2  << ShowWindow(1);

Re: Center non-modal window on display

txnelson — Fri, 13 May 2022 15:29:09 GMT

Your method is the method I normally use.

Re: Center non-modal window on display

ErraticAttack — Fri, 13 May 2022 23:47:30 GMT

In my experience the <<Get Window Size method is not reliable. The issue is that <<Get Window Size does not return physical pixels but logical pixels (affected by Windows display scaling), while <<Move Window( x, y ) uses physical pixels. Also, JMP in general and <<Get Window Size in specific does not update when the Windows display scaling changes (if a user starts JMP on a laptop and later hooks up a monitor, for instance).

I run the following PowerShell script from JMP to get the actual screen resolution and use this info to place windows as appropriate (you'll have to launch powershell with -ExecutionPolicy Bypass:

Add-Type @"
using System;
using System.Runtime.InteropServices;
public class PInvoke {
    [DllImport("user32.dll")] public static extern IntPtr GetDC(IntPtr hwnd);
    [DllImport("gdi32.dll")] public static extern int GetDeviceCaps(IntPtr hdc, int nIndex);
}
"@
$hdc = [PInvoke]::GetDC([IntPtr]::Zero)
[PInvoke]::GetDeviceCaps($hdc, 118) # width
[PInvoke]::GetDeviceCaps($hdc, 117) # height

Re: Center non-modal window on display

mringqui — Mon, 16 May 2022 20:17:39 GMT

This is the kind of hocus pocus I was looking for haha. Thanks Jim and Jordan! I will try out both options and see which is faster and/or more reliable

Re: Center non-modal window on display

SophieCuvillier — Wed, 24 Sep 2025 10:18:00 GMT

Hello,

Thank you very much for your tip ! It's been years, but it's still relevant: how do you transfer this information from PowerShell to JMP (about screen size) using Run Program?

Re: Center non-modal window on display

hogi — Wed, 24 Sep 2025 21:43:33 GMT

you can use text as Read function() and split the string by using words()

powershell_code ="
Add-Type -AssemblyName System.Windows.Forms
$primary = [System.Windows.Forms.Screen]::PrimaryScreen
Write-Output $primary.Bounds.Width
Write-Output $primary.Bounds.Height
";
        

result = Run Program(
	Executable( "powershell.exe" ),
	Options( {"-Command", powershell_code} ),
	Read Function( "text" )
);
        
{w, h} = Transform Each( {str}, Words( result, "\!n\!r" ), Num( str ) );