How to create a non-interactive window in MFC - mfc

In my application I have a window which I popup with small messages on it (think similar to tooltip). This window uses the layered attributes to draw alpha backgrounds etc.
If I have several of these windows open at once, and I click one with my mouse, when they disappear they cause my application to lose focus (it switches focus to the app behind the current one).
How do I stop any interaction in my window?

It works because OnSetFocus (like many of the On* methods) gives you a chance to pre-empt an action before it actually occurs. The focus never actually switches to your non-interactive window.

After playing with the WM_NCACTIVATE message with no luck, I overrode the WM_SETFOCUS message:
void CMyWindow::OnSetFocus(CWnd* pOldWnd)
{
if (pOldWnd != NULL)
{
pOldWnd->SetFocus();
}
}
That seems to do the trick. No idea why it works though! Comments welcome on that issue.

Related

Disable all top level window (WS_POPUP) when showing modal dialog

I have the main window, and then the user can "pop up" one of the frames in the application so that it floats rather than being contained in the main window. There are multiple frames that can be popped up so that in a given time there might be three WS_POPUP windows.
The problem is when I want to show the modal dialog, I can only disable one of them using the parameter in the DoModal function. How can I disable all top-level windows using DoModal? I can't simply disable the windows before showing modal and then enable it back because There could multiple chained modal dialog (one modal dialog opens up another modal dialog).
Does the API provide a way to do something like this? I've googled this for two hours and can't find a good enough solution. I'm using a combination of MFC, WTL, and ATL.
Thanks in advance!
As I understand the problem, it is the same like the MFC frame windows work.
In fact only the CFrameWnd of an MFC application gets disabled. On arrival off the WM_ENABLE message (with FALSE) BeginModalState is called and this function just disables it floating "child windows" of the CFrameWnd.
Same again, when EnableWindow (WM_ENABLE arrives with TRUE) is called for CFrameWnd. EndModalState is called and all disabled "child and floating" windows are enabled again.
See the MFC implementation of CFrameWnd::OnEnable, BeginModalState, EndModalSTate in the source code.
So you main window knows it's own popups. Upon launching the true modal dialog, and disabling this parent, it will disable it's floating popups.
The trick is that CDialog::DoModal needs the real parent... if not given in the constructor it guesses the correct one in most cases. For your case it should be necessary that you provide your "main window" as the parent window... same for message boxes...

Simulate mouse click in background window

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.

What would be the equivalent to SetForegroundWindow with X11?

I'm part of the SFML Team and we're currently looking into a feature to "request" window focus. The goal is to get very similar behavior across Windows, OS X and Linux.
For Windows one gets the rather simple SetForegroundWindow function via the WinAPI, which has a few condition as to how the window actually gets focus. The most important part to notice here is, that it only gets focus if it's from the same foreground process.
On OS X it's possible to get the focus for the active app only and otherwise let the icon bounce, i.e. notification.
Here comes the problem now, we'd like to get the same behavior on Linux as well, meaning the window should get focus if the window belongs to the active/foreground process and otherwise it should generate a notification. What would be the closest thing to that with X11?
There are already a few suggestions on the issue tracker of SFML, but none of them are actually implementing this behavior.
"User Story"
I guess developers can think of different things when being confronted with different technical names, as such here's the issue from a user perspective.
There are mainly two situations in which requesting focus is needed:
Sometimes when starting an application that uses a console window in the background, it can happen that the console window gets the focus instead of the actual GUI window. When this happens it's rather annoying for the user having to click on the window first. Since the console window and the GUI window are from the same application there's no harm done in switching the focus to the GUI window.
When one is writing an application that supports multiple windows, there might be situations where the application should decide which window gets the focus and again since the window belong to the same application there's no harm done in switching the focus from one GUI window to the other GUI window.
Further more if a different application has the focus/is being used then it's not okay to steal the focus and as such we just want to get the user's attention. For Windows that might be a blinking taskbar or for OS X that might be a jumping icon.
The current implementation seems to work fine on OS X and Windows, butwe're unsure about the X11 implementation. Thus the question is: How would one go about switching the window focus if the currently focussed window has been created by the same application that makes the focus request and otherwise create some kind of notification. For the notification we're/I'm not even sure if there's some generic way of doing it with X11.
In X11, "focus" means "the keyboard focus", that is, the window that gets the keyboard input. The window that has the focus is not necessarily in the foreground. This depends on your window manager focus policy. Most can be configured to have "click-to-focus" or "point-to-focus" policy. If you are interested in the keyboard focus, use XSetInputFocus. If you want to bring your window to the foreground, use XRaiseWindow.
It is OK to call RaiseWindow and XSetInputFocus once, when the application starts. It is also OK to bring a window to the foreground/set focus as a response to a user interaction with that or some other window of the same application. But it's not OK to do so as a response to some background event (time passed, file downloaded etc).
The standard X11 method of drawing attention to a window is setting the urgency hint. This will normally flash or bounce the icon, depending on your window manager. Do not forget to unset the hint when the user finally interacts with the window.
I think all of this has been discussed in the thread you have linked. I'm not quite sure which concerns are still left unanswered. Nothing can implement the exact same behaviour as with the other windowing systems, simply because X11 is not those windowing systems, and it's totally OK. X11, Mac OS X and Windows all behave differently and the users know and expect that. It would annoy me to no end if some application on X11 decided to behave exactly like it does on Windows, instead of toeing the X11 party line.

XP scrollbars going haywire in Windows7/Vista

I have this XP app (win32 C++) that I am just now testing under Windows7 (vista actually, but it does the same thing in windows 7).
I'm surprised that virtually the only issue I'm encountering is the following:
None of the scroll bars in a complex modelless dialog are functioning correctly. The main problem is the scroll thumb is not responding - just stays locked in position if you try and move it. Have had no issues going all the way back to win98, win2000, and winxp. Only in windows 7/Vista just now
But there is no commonality in the scrollbars in this dialog to explain it: One is in a plain richtext control created through a resource file. Another is in a richtext created through CreateWindow. And yet a third scrollbar is in a custom window class. None of them are working correctly (although you can make them scroll by right clicking and selected "Scroll Here".)
So I'm presuming maybe most encountered this a few years ago when porting to Window7/Vista for the first time, but I'm not finding anything in google now.
For modeless dialogs, you have to run IsDialogMessage in the main application GetMessage Loop, so messages for modeless dialogs are not subject to TranslateMessage and DispatchMessage. So I was doing that previously. However, Vista/Win7 doesn't like WM_MOUSEMOVE, and WM_LBUTTONDOWN and WM_LBUTTONUP to be bypassed like that for the dialog (i.e. they need to stay in the main App message loop). At least this was the problem in my case. I check for those message types now in the main message loop and that solved my problem. Can't explain it necessarily. Also couldn't explain why no one's encountered this previously (could be some idiosyncracy of my set up I guess). THanks for those who looked into this.

Managing Window Z-Order Like Photoshop CS

So I've got an application whose window behavior I would like to behave more like Photoshop CS. In Photoshop CS, the document windows always stay behind the tool windows, but are still top level windows. For MDI child windows, since the document window is actually a child, you can't move it outside of the main window. In CS, though, you can move your image to a different monitor fine, which is a big advantage over docked applications like Visual Studio, and over regular MDI applications.
Anyway, here's my research so far. I've tried to intercept the WM_MOUSEACTIVATE message, and use the DeferWindowPos commands to do my own ordering of the window, and then return MA_NOACTIVATEANDEAT, but that causes the window to not be activated properly, and I believe there are other commands that "activate" a window without calling WM_MOUSEACTIVATE (like SetFocus() I think), so that method probably won't work anyway.
I believe Windows' procedure for "activating" a window is
1. notify the unactivated window with the WM_NCACTIVATE and WM_ACTIVATE messages
2. move the window to the top of the z-order (sending WM_POSCHANGING, WM_POSCHANGED and repaint messages)
3. notify the newly activated window with WM_NCACTIVATE and WM_ACTIVATE messages.
It seems the cleanest way to do it would be to intercept the first WM_ACTIVATE message, and somehow notify Windows that you're going to override their way of doing the z-ordering, and then use the DeferWindowPos commands, but I can't figure out how to do it that way. It seems once Windows sends the WM_ACTIVATE message, it's already going to do the reordering its own way, so any DeferWindowPos commands I use are overridden.
Right now I've got a basic implementation quasy-working that makes the tool windows topmost when the app is activated, but then makes them non-topmost when it's not, but it's very quirky (it sometimes gets on top of other windows like the task manager, whereas Photoshop CS doesn't do that, so I think Photoshop somehow does it differently) and it just seems like there would be a more intuitive way of doing it.
Anyway, does anyone know how Photoshop CS does it, or a better way than using topmost?
I havn't seen anything remarkable about Photoshop CS that requries anything close to this level of hacking that can't instead be done simply by specifying the correct owner window relationships when creating windows. i.e. any window that must be shown above some other window specifies that window as its owner when being created - if you have multiple document windows, each one gets its own set of owned child windows that you can dynamically show and hide as the document window gains and looses activation.
You can try handle WM_WINDOWPOSCHANGING event to prevent overlaping another windows (with pseudo-topmost flag). So you are avoiding all problems with setting/clearing TopMost flag.
public class BaseForm : Form
{
public virtual int TopMostLevel
{
get { return 0; }
}
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool EnumThreadWindows(uint dwThreadId, Win32Callback lpEnumFunc, IntPtr lParam);
/// <summary>
/// Get process window handles sorted by z order from top to bottom.
/// </summary>
public static IEnumerable<IntPtr> GetWindowsSortedByZOrder()
{
List<IntPtr> handles = new List<IntPtr>();
EnumThreadWindows(GetCurrentThreadId(),
(hWnd, lparam) =>
{
handles.Add(hWnd);
return true;
}, IntPtr.Zero);
return handles;
}
protected override void WndProc(ref Message m)
{
if (m.Msg == (int)WindowsMessages.WM_WINDOWPOSCHANGING)
{
//Looking for Window at the bottom of Z-order, but with TopMostLevel > this.TopMostLevel
foreach (IntPtr handle in GetWindowsSortedByZOrder().Reverse())
{
var window = FromHandle(handle) as BaseForm;
if (window != null && this.TopMostLevel < window.TopMostLevel)
{
//changing hwndInsertAfter field in WindowPos structure
if (IntPtr.Size == 4)
{
Marshal.WriteInt32(m.LParam, IntPtr.Size, window.Handle.ToInt32());
}
else if (IntPtr.Size == 8)
{
Marshal.WriteInt64(m.LParam, IntPtr.Size, window.Handle.ToInt64());
}
break;
}
}
}
base.WndProc(ref m);
}
}
public class FormWithLevel1 : BaseForm
{
public override int TopMostLevel
{
get { return 1; }
}
}
So, FormWithLevel1 will be always over any BaseForm. You can add any number of Z-order Levels. Windows on the same level behave as usual, but will be always under Windows with level Current+1 and over Windows with level Current-1.
Not being familiar to Photoshop CS it is bit hard to know exactly what look and feel you are trying to achieve.
But I would have thought if you created a modeless dialog window as you tool window and you made sure it had the WS_POPUP style then the resulting tool window would not be clipped to the main parent window and Windows would automatically manage the z-Order making sure that the tool window stayed on top of the parent window.
And as the tool window dialog is modeless it would not interfere with the main window.
Managing Window Z-Order Like Photoshop CS
You should create the toolwindow with the image as the parent so that windows manage the zorder. There is no need to set WS_POPUP or WS_EX_TOOLWINDOW. Those flags only control the rendering of the window.
Call CreateWindowEx with the hwnd of the image window as the parent.
In reply to Chris and Emmanuel, the problem with using the owner window feature is that a window can only be owned by one other window, and you can't change who owns a window. So if tool windows A and B always need to be on top of document windows C and D, then when doc window C is active, I want it to own windows A and B so that A and B will always be on top of it. But when I activate doc window D, I would have to change ownership of tool windows A and B to D, or else they will go behind window D (since they're owned by window C). However, Windows doesn't allow you to change ownership of a window, so that option isn't available.
For now I've got it working with the topmost feature, but it is a hack at best. I do get some consolation in the fact that GIMP has tried themselves to emulate Photoshop with their version 2.6, but even their implementation occasionally acts quirky, which leads me to believe that their implementation was a hack as well.
Have you tried to make the tool windows topmost when the main window receives focus, and non-topmost when it loses focus? It sounds like you've already started to look at this sort of solution... but much more elaborate.
As a note, it seems to be quite well documented that tool windows exhibit unexpected behavior when it comes to z-ordering. I haven't found anything on MSDN to confirm it, but it could be that Windows manages them specially.
I would imagine they've, since they're not using .NET, rolled their own windowing code over the many years of its existence and it is now, like Amazon's original OBIDOS, so custom to their product that off-the-shelf (aka .NET's MDI support) just aren't going to come close.
I don't like answering without a real answer, but likely you'd have to spend a lot of time and effort to get something similar if Photoshop-like is truly your goal. Is it worth your time? Just remember many programmers over many years and versions have come together to get Photoshop's simple-seeming windowing behavior to work just right and to feel natural to you.
It looks like you're already having to delve pretty deep into Win32 API functions and values to even glimpse at a "solution" and that should be your first red flag. Is it eventually possible? Probably. But depending on your needs and your time and a lot of other factors only you could decide, it may not be practical.