The initial size is the same of the last closed window. ( in win o.s. )
Unless this is a file hosted over the network. If it's a hosted file, the size is that of the last window open the last time that the file was open in FileMaker Pro rather than server.
But you can use scripting to set the window size to whatever you want and this script can run each time you first open the file. This script can even open the window to different sizes for different monitors or for different users.
Thanks for your suggestions. Here is what I ultimately want to achieve and my reasons for asking about this.
I have 6 layouts that when called I want to always be maximized - modal if you like. The user would not be able resize them or close them.
On these layouts are several buttons that do 'stuff' and might open up secondary smaller windows the user interacts with.
My problem is that as soon as one of these secondary windows is opened the main window resizes from maximum to the startup window size. I want it to stay maximised and in the background.. Once the user has finished interacting with the secondary windows the main window would still just be there and maximised.
I hope this makes sense. Basically I want the experience to be like an unwindowed program. One of those six layouts is always there and the user can toggle between them. Other stuff happens in front of them.
This is understood, but is not, in fact possible in FileMaker for windows. Opening a second window will always drop the current window out of maximized state. What you can do is set up the script that opens the new window to use move/resize to resize the original window back out to almost maximized dimensions There are get functions that you can use to calculated these dimensions. Then, when the smaller window is closed, you can once again maximize the original window.
Some developers advise never using maximized windows due to this complication, but I personally do not like the "window inside a window" and added scroll bar confusion this can cause.
Another option to consider if you are using FileMaker 13, is to not open those smaller windows. Use a popover button instead of that smaller window. This allows you to open what is functionally a smaller dialog without ever having the original window drop out of maximized state. And note that if you give the popover panel an object name, a script can open the popover using Go to Object. The popover button can even be made invisible by specifying a "Hide Object When" expression of: True.
Thanks for the suggestions. I like the idea of popovers on so many levels. But although I can use FMP13 most of the users are still on earlier versions and I don't want to force them into upgrading at this point as I assume if I develop in FMP13 and they use FMP12 the popovers won't work.
Supplementary question if I may.
Is there a way to set the overall Filemaker window size?
Not from within FileMaker. I suspect that the correct system script or batch file might work to modify the size of the application window, but if you maximize this window to fill your monitor, in most situations, you no longer have to worry about that window as this is something your Client's FileMakerk application will "remember" for next time. (Where I was looking in to this, was to support a system that required the application window to be sized to span two monitors at the same time.)