X11 unable to maximize applications when no window manager is used - x11

We have a Linux based system that does not use a Window manager. When we start certain applications (for instance Firefox) from a terminal window (e.g. Firefox &) we find that no matter what we do, we can't get the application to display full screen.
If we run xrandr, it shows the default resolution is 1280x1024, but when we try to maximize Firefox (by pressing F11) the application is only sized to 1203x650.
Another application that seems to have the same problem is the evince PDF reader.
Our application is not configured to run a window manager (and we don't want to add one), so I'm wondering if there is something else that we can do to get these applications to render full screen.
Thanks...

Although you don't want to use a window manager, you might need to use a window manager.
I haven't dug into the X server sources around this, so I can't definitively say X requires a window manager to run properly. But as somebody who writes X client code, and hacks the X server, on minimalist embedded devices with small screens, low CPU power and no GPU... let's just say, all the major players in that space use one, and have good reasons for it.
If you want to avoid chewing up a lot of disk space, RAM or CPU power doing window management, you should check out matchbox. It's a low-footprint window manager designed to meet those criteria, and it's what many folks in that minimalist embedded space are using. My employer uses it on cell phones, configured so that only one app at a time is visible to the user, and the foreground app takes up the whole screen with no window borders. But you can use it other ways, too - Nokia uses it for their Maemo-based network tablets.

You could use xwit(1) to forcibly resize and place the windows. But as as far as I know, X11 in itself does not have the concept of a "maximized" window; the very idea is only added by most window managers and/or applications (like Firefox).

Does passing the "-geometry=1280x1024+0+0" option to Firefox help?

Oh, also... if you don't explicitly set a window manager, you might be unexpectedly falling back to the default X11 window manager. If you're not absolutely positive there's no window manager, you should check into this possibility.

Related

X11 (xquartz) window stacking

First, I'm fairly new to how programs interact with X11 window managers. I frequently use ngspice for circuit level simulations and one of the most commonly used tasks is to plot waveform using Nutmeg post processor. Whenever multiple X11 windows are invoked through terminal.app , for some reason all the windows stack on one another. Is there a way or hack to open any new x11 window not overlapped/stacked on an existing window?
Thanks for reading.
Window placement is handled by the window manager. I see that you tagged this MacOS, so I am guessing that you are running X11 applications through MacOS. I don't use MacOS, so I'm not sure what your WM is, but it's really up to the WM to decide. If you have some Xlib or XCB functions to work with, you can probably set some hints for placement using XChangeProperty (Xlib) or xcb_change_property (XCB). There is no way to guarantee that the WM will do anything with them, but it may. You can also move and resize windows using XConfigureWindow/xcb_configure_window.
In a nutshell, placement is handled by the WM, which may do it however it wants, and windows aren't required to listen to any requests made by other applications. All you can do is try some things and see what works.

multiple monitor support in application

What does it mean by multiple monitor support for an application?
In the old days computers only ever had a single screen attached. Now they often have more than one attached and a desktop that spans those screens.
You need to make sure that your app:
Maximises to the monitor that it is most closely associated. A badly written app might always maximise a window to the primary monitor.
Remember which monitor it was displayed on when last run, and restore to that monitor when it starts up again.
Avoid displaying on a monitor that is no longer available. For example, consider a laptop with an attached screen. If you show the window at coordinates for a screen that has been disconnected (e.g. laptop user on the move) then they won't be able to see it.
It all depends on the application.
For some applications it just means that that you could open a very big window.
For others it might mean that you could open two windows, one for each monitor. For example, Lightroom, lets you view a collection of thumbnails on one window and a full-sized image on the other.

How can I find out or record the X11 top-level window from which a top-level window was opened?

I'm thinking of writing an X11 window manager which does for windows something like what TabKit does for tabs in Firefox (in its default tree view mode). To do this, I'd need to be to able to find out which window a window was opened from. Is there a standard way of finding this out?
(I've never done any X11 programming without using a cross-platform toolkit on top of X11, let alone writing a window manager.)
For the difficult cases - applications launching other applications, e.g. a word processor launching a web browser - there's going to be a need for co-operation between applications to track this information. The Zeitgeist project already seeks to track which documents were opened from which documents, which is close enough that I should probably work with Zeitgeist (and/or its KDE equivalent - Nepomuk?) to get this implemented.

Does Windows 7 treat full-screen applications differently?

I have a hidden process that waits for non-standard hardware button messages and runs an application (with CreateProcess). No problem with the user disturbing, it's an action that the user approved himself. Everything is fine when it's usual layout with taskbar shown and multiply captioned and non captioned- windows. But the situation is different in XP and 7, when the current application is full-screen. Full-screen application in this case is window without borders having exactly the same dimension as the screen. Windows hides taskbar for such application even if it's always on.
In Xp, it's ok, the taskbar is being shown in this case and appication (for example calculator) also, the full-screen app is still visible in areas other than the launched app's and taskbar'. But in Windows 7 nothing visual happens, the full-screen app is still on and if I switch to taskbar, the executed application is there. I tried to solve it with SetForegroundWindow, BringWindowToTop, even AllowSetForegroundWindow(GetCurrentProcessId()) call for a window handle found with CreateProcess-WaitForIntputIdle-EnumThreadWindows, no change. So did something change since XP related to full-screen windows that officially documented?
Thanks,
Max
I would imagine that, if you have your own hardware device, that there is some API for generating "real" user input. Clearly the legacy keyboard and mouse, and now USB HID drivers (many of which are usermode I think?) have access to an API to do so.
Synergy+ for example can generate fake keyboard and mouse events on connected PCs, and the consequence of the faked input is windows switching activation normally.
So, my initial idea is for your usermode "Device" application to synthesize actual keyboard messages - SendInput seems a likely candidate for "the API that can "fake" real user input events.
Then, use an API like RegisterHotKey in your "UI" app to respond to the hotkey combination your device app generates.
Now, (assuming that SendInput IS generating user input events at the correct level), you should (from within the WM_HOTKEY handler in your UI app) have permission (because everything was "user initiated") to change the foreground window (to yourself).
Vista introduced the desktop composition feature. In short, all windows are drawing to a memory bitmaps and the Desktop Window Manager is then composing these bitmaps and drawing on a full-screen Direct3D surface. Full-screen windows do not participate in the desktop composition and get to draw directly on the screen (mostly because the majority of full-screen apps are games that need real-time screen updates).
In particular, this means that when a full screen app is up and running, it is covering the DWM composed image and the user needs to switch to a DWM-managed window for the DWM to start drawing on top of the full-screen app.
I don't have a good solution for your problem, unfortunately. One way to solve it would be to add the WS_CAPTION style to your app and then handle WM_NCPAINT/WM_NCCALCSIZE/WM_NCHITTEST yourself. This would allow you to lie to the DWM that you are a regular windowed application, but change visually your NC area to look like you have no title. However, this does require certain amount of additional code and might be a bit more effort you want to invest.
Another way you can try to solve your problem is to explicitly minimize your full-screen application window when launching the new process. However, you will then have to solve the problem of when to maximize it back again.
Btw, you might find the comments on this post from Raymond Chen interesting.
Windows supports multiple desktops and my guess would be that the full screen up is using a different desktop than the default one (where your application will be shown). A desktop object in Windows is "a logical display surface and contains user interface objects such as windows, menus, and hooks". For example, screen savers normally are started on a separate desktop.
You can find out which desktop an application is running on using Process Explorer:
Set Process Explorer to replace Task Manager and to run always on top.
When your full screen up is shown, launch Process Explorer by pressing Ctrl + Shift + Esc
Within Process Explorer, select the full screen process and press Ctrl + H to display the handles of this process
See the value of the Desktop item in the list. Usually this would be set to Default
If you know what desktop this app is running on you can start your process on the same desktop by first calling OpenDesktop to get a handle to this desktop and then pass it into the STARTUPINFO of your CreateProcess call.

Defaulting to full screen or allowing users to choose default at first startup?

In a fairly graphics intsensive application the requirements state that it should default to full screen mode even though the application is running under Windows. I know many games do this but I find it annoying. The default IMO should be to open in a window rather than full screen mode. I am proposing the first time the user runs the application they should select the default behavior. Am I wrong?
I think the annoyance-factor depends a lot on what the application tries to do.
If it is some utility that I might start while working in 5 different applications and it forces its fullscreen-ness on my, then I'd get highly annoyed.
If it is a specialized application that helps me with the entire workflow of a given task (so that I never or rarely need any other apps open at the same time), then fullscreen might actually be a valid default.
Whatever you do, just make sure that toggling the startup behaviour is very discoverable. Because no matter which way you'll go, some of your users will disagree with your decision. And for them it should be very easy to change to their prefered way.
I would follow the requirement the first time the application is launched. I would also provide a simple way to switch from full screen to windowed, for instance by pressing ESC (and another way to go back to full screen). Then I would store the mode when quitting the application and restore this mode at next launch.
Before doing the opposite of what your requirements say, I'd have the requirements changed.
However, what about giving the user the choice at install time?
The window at first-start-up should default to the optimal size for the largest proportion of users. For a graphics-intensive full-featured app, that may very well be full screen.
As for individual user preferences for window size, it seems to me most users won’t know if they want full screen or not until after they’ve started to use the app and see how much screen space they need and how much they use the window in conjunction with other windows. Asking them which size they want at install or first-start-up could thus be annoying and even confusing. It’s better to put such a setting under Options/Preferences.
Perhaps the best thing to do is save the window status on exit. Users who like it non-maximized thus only have to non-maximize it (and size it) once and then forget about it. The only consideration is to have some way to reset the window to the default (e.g., Window > Standard Size menu item) for novice users who accidentally resize or reposition the window to something bizarre and don’t know how to get it back. Alternatively, you could have a Window > Keep Sizes and Positions menu item for users to explicitly save the window status across sessions.
Go back to the requirements writers and ask them if they have considered non-traditional monitor setups, such as:
30" or larger monitor. Do you really want your app hogging up all the screen real-estate?
Multiple monitors. Which monitor will you run on? Can the user move your app from one monitor to another? Can your app span more than one monitor?
Virtual desktops. Can the user move your app from one desktop to another? Can they switch desktops while your app is running? Can your app span more than one desktop?
Such setups are increasingly common, especially large monitors. IMO, full-screen mode (the default for many older Windows apps) is becoming less and less useful.
The problem with presenting the user with the option of initially selecting fullscreen / vs windows is that they haven't used the software yet. How can they make a decision on which is better for them, without experience?
I would run the app in whichever mode provided the best user experience and then offer an option to change it both in the Preferences and though a hint while starting up the application for the 2nd time.

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