I have three executables compiled from Visual C++ using OpenGL libraries. Though nothing is different between them in how the window is created, one of them automatically has focus when I run it and the other two require the user to click on the window before they are given focus.
I'm building a WIN32 application as a menu to run the different .exe files, and in here I'm using all the usual suggestions to attempt to focus the windows (SetFocus(hWnd) SetActiveWindow(hWnd)), but to no avail.
Any advice?
What you want is actually SetForegroundWindow (...), because in addition to setting the active window, this will bring your application into the foreground.
SetActiveWindow (hWnd) will only accomplish what you want if your application is in the foreground, it is useful if you have a multi-document application and want to switch between windows.
Here is a relevant selection of code that I use in my Win32 window management system when initializing / resizing a rendercontext:
ShowWindow (hWndRender, SW_SHOW);
SetForegroundWindow (hWndRender);
SetFocus (hWndRender);
Related
I'm working on a cross-platform command-line application (in C++ on
Win/Linux and ObjC++ on OSX) which sometimes creates an OpenGL
context. The OpenGL context and window creation code is obviously
different for the different platforms, but on OSX it's done through
NSOpenGLView and NSWindow. There's no nib, and it's not built with
Xcode (it uses a cross-platform build script).
On OSX, the window is created and works fine, but the OpenGL window
doesn't show up in the Application Switcher (Cmd-Tab). This means
that it's tricky to find the window if you 'lose it' behind other
windows, and can often only be found by going to Mission
Control/Expose.
My question is: is there a programmatic way (i.e. a message to send to
the NSWindow object or NSApplication) to ensure that a (unix-style)
command line application will show up in the Cmd-Tab list once the
window is created?
You need to transform the process from an accessory to a regular app. Call [NSApp setActivationPolicy:NSApplicationActivationPolicyRegular].
Once you do that, though, the app will also have a menu bar when it's active. This is good because it's what users expect. However, you probably need to add appropriate items to the menus in that menu bar to get a decent user experience.
Your app will appear in the Dock as well as the Command-Tab application switcher. By default, an unbundled executable will get an icon that looks like a CRT display showing the word "exec". You can use [NSApp setApplicationIconImage:someImage] to set a better icon, although the Dock will revert to showing the generic executable icon briefly as the process exits.
If my wxWidgets application creates a new window while the application does not have focus, its taskbar icon blinks yellow until I switch to it, as shown here:
This is annoying. How can I prevent this from happening?
EDIT: The original version of this question suggested the blinking was happening during startup. After further investigation, this is not occurring right at application startup; rather, it occurs if I create an additional window while the application does not have focus.
To give a bit more background: my application is a sort of server, that opens windows in response to network events. If I boot up the application, then switch focus to something else and a network event comes in while the focus is elsewhere, my application will open a new window in the background (not grabbing focus) and this blinking will occur.
The windows are wxFrames; the application constructs them and their child widgets, then calls Show(true) on the frame.
Also, I've attempted to set a breakpoint on the FlashWindow Win32 API function, hoping to trap wherever in WX it's getting called, but haven't been able to make that work.
Maybe the following would work:
wxTopLevelWindow::ShowWithoutActivating ( )
http://docs.wxwidgets.org/trunk/classwx_top_level_window.html#a03e526f505716568318d601318527bd0
Yes. If you create a new top level window while the app does not have focus, then the task bar icon will flash. This is the intended behaviour of the windows operating system.
I'm currently working on a Win32 program which requires a main window containing many child window controls - buttons, listviews and so on. I believe the standard way to build such a window is to first call CreateWindow for the main window, then again for each of the controls.
As an easier option, I'm considering designing the main window using the resource editor's dialog box designer, then using CreateDialog to build the main window in one go.
By using a CLASS statement in the dialog box template, I should be able to get the main window to use a custom window class (and hence a custom window procedure) and thus avoid the window having any dialog-like behaviour. An example of this technique can be found in Charles Petzold's "Programming Windows": the HEXCALC program in chapter 11.
Are there any downsides to creating my main window in this way? If so, what are they? If not, why is this approach rarely used?
You don't get control of your main window message loop - the dialog manager handles it for you. On the other hand, the dialog manager handles keyboard accelerators, tab ordering and a number of other effects.
You'd be surprised what you can do with a standard dialog box - the windows volume control is implemented with about four different dialog boxes - it has a frame dialog box which in turn host hosts a tray window which in turn holds volume control dialog boxes, one for each app volume.
The only downside of CreateDialog I know of (as compared to repeated CreateWindow, not talking about some heavyweight framework, just Win32 vs Win32) is that dialog resources position child windows using dialog units. So the layout is dependent not only on DPI, but also on the user's theme settings (choice and size of font).
If any of your controls need to have fixed sizes in terms of pixels, you won't be happy with the dialog-provided positioning and will need to go through and move all the child windows after the fact.
So yes, you can use CreateDialog as a shortcut for creating a bunch of windows with specified classes and styles. But no, you can't do your layout in the dialog editor.
OTOH, you could store the DLU <-> pixel conversion used on your design machine, and then learn enough about parsing the DIALOG resource internal format to pull out the positioning information, then convert to pixels and correct the positioning in more automated fashion.
You will be able to have the full control over your window, even if it was created with CreateDialog.
Normally, when you create your own window (of your class), the window procedure used is the one that you registered with the class. OTOH windows created via CreateDialog will have the dialog standard window procedure (DefDlgProc), which will mostly invoke your supplied "dialog handler".
If you want to have full control of all the messages you may replace the window proc of the newly created window right after its creation. Just call SetWindowLongPtr with GWLP_WNDPROC parameter. Still, you may do the auto processing of some dialog-specific things by calling IsDialogMessage within your procedure.
There is no downside whatsoever.
Why is it rarely used? Because:
People normally use DialogBox instead, since that is easier for simpler cases.
For more complex cases, people use things like MFC or ATL (or some external library like GTk or Qt), and don't bother with native Win32 graphics.
There are no downsides using the Windows SDK, internally libraries like MFC use the Windows SDK .
People tend to use libraries like MFC over Windows SDK, as libaries have the readymade stuff. However Windows SDK calls are faster than library calls, so in some situations developers call Windows SDK directly .
CButton btnOk ;
btnOK.Create(_T("Press Me"), WS_CHILD|WS_VISIBLE|BS_PUSHBUTTON,CRect(100,100,300,300), pParentWnd, 1);
is similar to the following code ,
HWND hWnd = CreateWindow("BUTTON","Press Me",WS_CHILD|WS_POPUP|BS_DEFPUSHBUTTON,100,100,300,300,NULL,NULL,GetModuleHandle(NULL),NULL);
ShowWindow(hWnd,SW_SHOW);
How do I make a process go the background programatically?
What I want is for the user to double-click the process executable, and it just goes into the background ... and does not open a window while executing.
Any code snippet in visual c++ would be very helpful
Have you considered creating a Windows Service instead? They're specifically designed to run in the background without showing a UI.
Otherwise, just create an application without a window.
I know this is old, but I thought I would post something for when people find this through search.
While I like Cody Gray's answer for design correctness, sometimes you don't have a choice.
If you want to launch a program without jumping to the new window (it appears in the background or minimized) or not create a window at all try looking at the ShellExecute and ShellExecuteEx functions. The argument nShowCmd (or nShow) gives you (among others) the options:
SW_HIDE
Hides the window and activates another window.
SW_SHOWMINNOACTIVE
Displays the window as a minimized window. The active window remains active.
As the documentation says, SW_HIDE creates a process running the executable you give it, but if this program would normally create a window, none appears.
This might help: http://ss64.com/nt/start.html
I tried this way and it worked fine:
Create a console application and write your codes in the sub main as any other console application.
Now change the application type in the project properties to windows Forms application from Console application
thats it
There are cases when one needs to start a process based on some events not involving activity of the mouse of keyboard (from hardware or time-based). It works with ShellExecute and ShellExecuteEx generally, but if there's a full-screen app (the one, created borderless with exactly the dimensions of the screen), this launched application don't become active or even visible. Is there a technique to bring such application to top over this full-screen app? I'm aware about ShellExecuteEx and hProcess manipulation, but it seems it involves very recent api (GetProcessId) and seems that this function has some limitations related to user rights.
Thanks
You can use
SystemParametersInfo (SPI_SETFOREGROUNDLOCKTIMEOUT, 0, (PVOID)0,
SPIF_SENDWININICHANGE | SPIF_UPDATEINIFILE);
to do so before the process start, but you should do this temporary like described in How to ensure process window launched by Process.Start(ProcessStartInfo) has focus of all Forms?.
Please do this only you really need to start a process on top.