I am working on a MFC C++ application. I was working on a dialog that has SystemMenu property set to FALSE, so it does not have the ability to maximize. I want to handle the double-click message on the title bar. How can I do that?
EDIT:
I hope this time it will be clear for everybody. I have a dialog that does not have system menu (and system buttons or icon). When the user double-clicks the titlebar of that dialog, I want the program to call function x();.
Technically, you would have to handle WM_NCLBUTTONDBLCLK and check if the double click occurred in the caption area of the window, possibly by sending it WM_NCHITTEST and testing that the return value is HTCAPTION.
(Update: As JohnCz rightfully points out, sending WM_NCHITTESTis not actually necessary, since WM_NCLBUTTONDBLCLK already carries its result in wParam.)
Then you would only have to send WM_SYSCOMMAND with SC_MAXIMIZE in wParam to the window to maximize it.
In practice, however, it will not achieve much if your dialog box is not ready to handle size changes and layout its controls accordingly. This feature did not come out of the box in MFC last time I checked.
I think there is some kind of confusion here:
Frédéric Hamidi
You are correct, handling WM_NCLBUTTONDBLCLK message is the right way to go, however it is no necessary to call HitTest, since WM_NCLBUTTONDBLCLK message delivers hit information that MFC framework translates in the WM_NCLBUTTONDBLCLK handler.
Victor,
What is exactly that you are trying to achieve by handling WM_NCLBUTTONDBLCLK message?
Maybe there is some other way to fulfill your requirement once you make it clear to us.
The fact that you do not have system menu, does not prevent your app from receiving non-client area messages.
Related
Fig1:
Fig2:
As in Fig1, after I clicked radio button, the radio button seems not get correctly painted, seems 50% transparent.
As in Fig2, after I move my mouse to hover the radio button again, it got correctly painted.
I have no idea about what is going on behind.
What are the possible reasons?
By the way, after I pressed a shortcut key PrtSc to get a screenshot(a freeware: Greeshot), this problem disappeared.
One hint I just found is: the dialog holding the radios were in modeless mode. The problem disappeared after I showed it as a modal dialog.
Actually, to achieve below goals, I am implementing the message pump for this dialog. Perhaps I am doing something wrong in the message pump logic. Continue to check the pump.
My Goal: user can interact with other windows while showing this dialog, one exception is: user should not be able to interact with the parent dialog of this dialog in question, so that database transaction may be issued prematurally.
I used to have a similar problem within wxWidgets. Turns out it's a long lasting bug that really never had been fixed. I now use a workaround with a simple wrapper function that 'enables' the element (places focus on it) and then 'unfocuses' it. Not sure in your current setup.
As a result, it seems I did something wrong in the message pump for the dialog in question.
I am implementing the message pump for this dialog.
To avoid user interact with the parent dialog of the dialog in question, I was ignoring message for the parent dialog and to children of parent dialog.
After I changed the above logic to below, the problem got solved.
EnableWindow(hParent, FALSE);
EnableWindow(hParent, TRUE);
So, I think I was doing something wrong in ignoring message, not sure exactly where.
I'm trying to use SendMessage to post mouse clicks to a background window (Chrome), which works fine, but brings the window to front after every click. Is there any way to avoid that?
Before anyone says this is a duplicate question, please make sure that the other topic actually mentions not activating the target window, because I couldn't find any.
Update: aha, hiding the window does the trick, almost. It receives simulated mouse/keyboard events as intended, and doesn't show up on screen. However, I can just barely use my own mouse to navigate around the computer, and keyboard input is completely disrupted.
So my question is, how does sending messages to a window affect other applications? Since I'm not actually simulating mouse/keyboard events, shouldn't the other windows be completely oblivious to this?
Is it possibly related to the window calling SetCapture when it receives WM_LBUTTONDOWN? And how would I avoid that, other than hooking the API call (which would be very, very ugly for such a small task)?
The default handling provided by the system (via DefWindowProc) causes windows to come to the front (when clicked on) as a response to the WM_MOUSEACTIVATE message, not WM_LBUTTONDOWN.
The fact that Chrome comes to the front in response to WM_LBUTTONDOWN suggests that it's something Chrome is specifically doing, rather than default system behaviour that you might be able to prevent in some way.
The source code to Chrome is available; I suggest you have a look at it and see if it is indeed something Chrome is doing itself. If so, the only practical way you would be able to prevent it (short of compiling your own version of Chrome) is to inject code into Chrome's process and sub-class its main window procedure.
I am currently developing a user interface DLL that uses the WIN32 API. The DLL must work for numerous platforms, XP, WIN CE, etc. I have managed to incorporate docking, anchoring and so on but appear to have a problem regarding owner-drawn buttons. I can draw the button's correct state, focus, clicked, default. However, I cannot receive key notifications. I specifically want to perform a click operation on a button that currently has focus, should the user press enter.
Note that I am using a windows message loop rather than a dialog message loop. I use windows hooks to hook into the window creation and set the user data to 'point' to my control instance. If I test for WM_KEYDOWN in the main message loop I can get a handle to my button control instance and could forward the message to the relevant control. Unfortunately, I am dealing with a lot of legacy code and this may not be an ideal solution.
So, my question is what is the best way forward. Is subclassing the button control's window procedure a viable option or is there an easier way?
Many thanks in advance.
The comments above are correct. The button with focus should be getting the key messages. But buttons don't (by themselves) respond to Enter--they respond to Space. It sounds like what you're missing is the typical dialog keyboard navigation, like Tab key moving the focus and Enter activating the "default" button.
If you've got a typical Windows message pump, and you want the keyboard behavior normally associated with dialogs, then you need to use the IsDialogMessage API in your message loop. This means your window is essentially a "modeless dialog".
Looks like standard window proc subclassing should do the trick. See http://msdn.microsoft.com/en-us/library/windows/desktop/ms633591(v=vs.85).aspx for details.
In .Net there is a feature called KeyPreview. How can I do this in WinApi. Maybe I don't necessarily need this but my hWnd has WM_KEYDOWN, but it does not receive it when my Text Box has focus. How can I achieve this?
Thanks
*Using pure Win32API...
is there an alternative, how could I handle the Text Box's WM_KEYDOWN?
You can try subclassing the edit control. Either "instance subclassing", to trap messages for only one window, or "global subclassing" to trap messages for all windows of that class (in your application, not system-wide).
The example here (http://msdn.microsoft.com/en-us/library/ms997565.aspx) shows how to subclass an edit control and trap the WM_GETDLGCODE message -it wouldn't be that difficult to change it to WM_KEYDOWN.
You may have problems previewing the keys used for dialog commands, e.g. TAB or RETURN, as they may be trapped higher up the food chain. You may need to look at changing WM_GETDLGCODE as well.
If you use MFC you can look at PreTranslateMessage (I am not sure regarding to PreTranslateMessage, but you can easily to verify whether to enough to override the function).
You can set keyboard hook.
There is no such a possibility in WinAPI to catch the messages belonging to controls in window procedure of parent window (although some exceptions exist).
What .NET basically does is that it routes all messages of all controls including their parent window to a single window procedure. Then it's easy to catch all the messages in one place.
This is your way to go - to set window procedures of all the controls into single procedure and there to catch all the messages
As window procedure also receives hwnd parameter, it's then also easy to determine the control to which the message belongs.
How would one prevent the little dotted square that appears on a button when it has the keyboard focus in a dialog. (w/ apologies for the technical jargon). At one point I hacked together a solution by subclassing a button WindowProc and subverting some windows messages, but wanted to know the correct way.
There's actually a problem with another control in the dialog also involving the keyboard. This other control is actually also a button, but being used as a group box or panel, not as a functioning button. But when I hit the tab key in the dialog, this group box "button" comes to the foreground obscuring the static controls on top of it, so I wanted to prevent that.
For both of the above, I tried turning off WS_TABSTOP - didn't help.)
Both of my problems mentioned above were solved by subclassing the WndProcs and returning 0 in response to message 0x128 and discarding it. Even Spy++ could not identify this message 0x128, and I don't have it in any header. But its sent to every control in the dialog the first time tab is hit in the dialog.
(I did try BN_SETFOCUS as described above and also WM_SETFOCUS but it didn't help.)
So if anyone knows where to find what windows message 0x128 is...
The correct way is to write your own button control instead of using the default Windows one.
Alternatively, you can prevent if from ever getting keyboard focus.