Floating/Always above dialog - c++

I've noticed in GIMP that when a dialog is opened it does not disable the parent window. The parent window can still be used, while the child window floats in front of it.
I want to do the same thing, how ever for me when I click on my parent window it pushes the children to the back, such that the parent comes to the front.
I'm using Qt QDialog's but happy to do platform specific code to get this working.
I've been looking here:
http://msdn.microsoft.com/en-us/library/ff700543(v=vs.85).aspx
but nothing seems to do what I'm after. I have a dodgey solution currently where I set the window to HWND_TOPMOST when my app receives focus, then disable this when it looses focus, but its not ideal as message boxes are being pushed behind these top most windows.
ie.
SetWindowPos(winId(), stayOnTop ? HWND_TOPMOST : HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOACTIVATE);

Looks like I didnt have parenting setup correctly on my dialog! It needed to be parented to the parent dialog/main window and then it just works.

You need to call setWindowFlags() including the Qt::WindowStaysOnTopHint flag.

Related

Create a window using the WS_EX_NOACTIVATE flag ,but it can't be dragged until I release the mouse

I have created a window using the WS_EX_NOACTIVATE flag and it works great as far as not taking focus when you click the window. However when I drag the window or try to resize it, it doesn't redraw the window as your are moving and resizing it, only at the very end once you release the mouse button. Is there a way around this? I would like to see the window as I am resizing it. I have searched many documents, but I still don't find the resolution...
If you need a window that doesn't take focus when clicked, but can still be interacted with, you need to handle the WM_MOUSEACTIVATE, and return MA_NOACTIVATE.
Additional information and fully working sample code has been published by Raymond Chen. See How can I have a window that rejects activation but still receives pointer input?
It's a Windows bug. You need to call SetWindowPos(hwnd, 0, x, y, width, height, 0) on WM_MOVING. The coordinates to set are given to you in lParam which is a RECT*.
Note that doing this will activate the owned window and deactivate the owner, which is not what you want (and SWP_NOACTIVATE has no effect either).
To avoid that, you need to set WS_CHILD on the owned window. But set it after you created the window, via SetWindowLong(), otherwise your owned window will get clipped, like any child window.
And, as you probably already figured out, this only works for windows with WS_EX_TOOLWINDOW ex style. I wasn't able to make the owned window stay deactivated with any other style combination that doesn't include WS_EX_TOOLWINDOW.
That's winapi for you :(

Wrong window painting behaviour in frameless Qt window (win32)

I have an QML application (also tested it with QWidgets, same problem) and to make it borderless (but still support the native WM features like aero snap, etc) I followed this by implementing an QAbstractNativeEventFilter and responding to the WM_NCCALSIZE signal with zero:
switch(msg->message) {
case WM_NCCALCSIZE:
*r = 0;
return 1;
...
}
I also set some window flags which are not in the Qt Namespace with
SetWindowLong(hwnd, GWL_STYLE, WS_OVERLAPPEDWINDOW | WS_VISIBLE | WS_CLIPSIBLINGS | WS_BORDER | WS_SYSMENU | WS_MINIMIZEBOX | WS_MAXIMIZEBOX | WS_THICKFRAME);
This works fine until I move or resize the window which causes Qt to rerender and a unpainted area width the width of the title and the borders appears:
Before moving/resizing
After moving/resizing
I also found a workaround for this by adding the FramelessWindowHint flag in Qt:
window->setFlags(Qt::FramelessWindowHint | Qt::WindowSystemMenuHint | Qt::Dialog);
But now this margins occurs again when the window state changes (maximizing, minimizing, ...). By blocking the WM_SIZE event for example when SIZE_MAXIMIZED is the parameter the margin doesn't appear but then I also am not able to maximize the window from Qt. This means it is a Qt side problem.
I also noticed by inspecting the window style with winspector, that after I have maximized it a new property atom appears:
Can you help me fixing this?
I think using SetWindowLong on your window handle and using the Qt Window Flags/Qt Widget Attributes is asking for trouble. You can go and look at the Qt source to see what happens when processing those window flags.
When I've created frameless windows, I've usually done it to prevent moving and resizing, because I am managing all that separately.
One problem that I had related to it, was when the On Screen Keyboard came up and docked, it would resize my windows. So besides calling resize() I had to also use setFixedSize to prevent my widget from getting manipulated when the operating system attempted to change the size of the window.
So in other words, I would add an application wide QShortcut, listening for the snapping keyboard shortcuts and resize your window the way you want it to when it happens, if you are managing a frameless window.
Hope that helps.
I wonder if this was a flaw of Qt message relay, coz I met with a similar problem which occurs on nested windows. If you press SIZE_MAXIMIZE or SIZE_MINIMIZE button of the parent window, the child window sometimes is not able to receive WM_SIZE message. I suppose there are roughly two solutions: 1. Fix Qt, 2. Work it around.
Here I have a OGL rendering child window, sometimes even the WM_SIZE message is not correctly passed. That is, if you resize parent window, you get part of the client area black.
I just use a simple workaround to fix this, which check the current size with the cached one, and make a sort of manually resize myself.

Fullscreen mode for ActiveX control

I tried to implement a switch-to-fullscreen mode for an ActiveX control. This currently works by removing and hiding the parent window and changing my control's placement and position.
However, I have a problem with switching between applications while the control is in fullscreen mode. If I switch to another application and then click on my window area (not in the taskbar), it seems to not be activated. You can see in the taskbar, that another application still has the highlight and on the main screen, my window is partly hidden behind the taskbar unless it has the focus.
I process the WM_LBUTTONDOWN window message to detect if my window is clicked. And I already tried to call the following WINAPI functions:
::ShowWindow(m_hWnd, SW_RESTORE);
::SwitchToThisWindow(m_hWnd, FALSE);
::SetForegroundWindow(m_hWnd);
::SetActiveWindow(m_hWnd);
::SetFocus(m_hWnd);
::BringWindowToTop(m_hWnd);
::SetWindowPos(m_hWnd, HWND_TOP, m_monitorInfo.rcMonitor.left, m_monitorInfo.rcMonitor.top, m_monitorInfo.rcMonitor.right, m_monitorInfo.rcMonitor.bottom, SWP_NOSIZE | SWP_NOMOVE | SWP_SHOWWINDOW); // SWP_NOACTIVATE, SWP_NOOWNERZORDER
I also tried to use ::SetWindowLongW(m_hWnd, GWL_STYLE, WS_VISIBLE); which surprisingly gave my window the focus back. But it then suddenly disappeared when trying to switch back from fullscreen mode again.
I have no idea why there are so many different functions that for me seem all to do roughly the same. But it doesn't matter as none of them worked anyway.
What is the/one correct way to behave my control correctly?
Windows might be getting a bit confused because you're filling the screen with a child window, but you want it to behave like a top-level (overlapped) window. The host application is probably not getting activated because you've hidden its window.
You might do better to create a new top-level full-screen window for full-screen mode. If this is owned by the top-level window that (ultimately) hosts your control then your new window will always be above it, so you don't need to hide the existing window. Activation should just work. In short, you want your window to behave like a pop-up modal dialog.
Adobe's flash player seems to do something similar. Full-screen playback is in a window of class ShockwaveFlashFullScreen.

Creating a Transparent Child window on top of non-transparent Parent Window (win32)

I have a program which is not written by me. I dont have its source and the developer of that program is developing independently. He gives me the HWND and HINSTANCE handles of that program.
I have created a child window ON his window, using win32 api.
First thing I need is to make this child window have transparency on some area and opaque on other area(like a Heads up display(HUD) for a game), so that the user may see things in both windows.
The second thing that I need is to direct all the input to the parent window. My child window needs no input.
I know that WS_EX_TRANSPARENT only makes the child draw at the end like in painters algorithm.
I cant use WS_EX_LAYERED because its a child window.
p.s.
I have looked everywhere but didn't find any solution though there were similar questions around the internet.
Actually this is a HUD like thing for that game. I can't draw directly on parent window because of the complexity with multi-threads any many other reasons.
-- EDIT ---------------------------
I am still working on it. I am trying different ways with what you all suggested. Is there a way to combine directX and SetWindowRgn() function or directx with BitBlt() function? I think that will do the trick. Currently I am testing all the stuff as a child window and a Layered window.
You can use WS_EX_LAYERED for child windows from Windows 8 and up.
To support earlier versions of windows, just create a level layered window as a popup (With no chrome) and ensure its positioned over the game window at the appropriate location. Most users don't move the windows they are working with all the time, so, while you will need to monitor for the parent window moving, and re position the HUD, this should not be a show stopper.
Not taking focus (in the case of being a child window) or activation (in the case of being a popup) is more interesting, but still quite do-able:- The operating system does not actually automatically assign either focus, or activation, to a clicked window - the Windows WindowProc always takes focus, or activation, by calling SetFocus, or some variant of SetActiveWindow or SetForegroundWindow on itself. The important thing here is, if you consume all mouse and non client mouse messages without passing them on to DefWindowProc, your HUD will never steal activation or keyboard focus from the Game window as a result of a click.
As a popup window, or a window on another thread, you might have to manually handle any mouse messages that your window proc does get, and post them to the game window. Otherwise, responding to WM_NCHITTEST with HTTRANSPARENT (a similar effect to that which WS_EX_TRANSPARENT achieves) can get the system to keep on passing the mouse message down the stack until it finds a target.
OK friends, finally I did some crazy things to make it happen. but its not very efficient, like using DirectX directly for drawing.
What I dis:
Used (WS_EX_TRANSPARENT | WS_EX_LAYERED | WS_EX_ TOOLWINDOW) and () on CreateWindowEx
After creating the window, removed (WS_EX_DLGMODALFRAME | WS_EX_CLIENTEDGE | WS_EX_STATICEDGE) from window styles, and also removed (WS_EX_DLGMODALFRAME | WS_EX_CLIENTEDGE | WS_EX_STATICEDGE | WS_EX_APPWINDOW) from extended window styles.
This gives me a window with no borders and its also now shown in the taskbar. also the hittest is passed to whatever that is behind my window.
Subclassed the window procedure of the other window and got the
WM_CLOSE,WM_DESTROY, to send the WM_CLOSE or WM_DESTROY respectively to my window
WM_SIZE,WM_MOVE, to resize and move my window according to the other window
WM_LBUTTONUP,WM_RBUTTONUP,WM_MBUTTONUP, to make my window brought to the top, and still keep focus on the other window, so that my window doesn't get hidden behind the other window
Made the DirectX device have two passes:
In the first pass it draws all the elements in black on top of a white background and copy the backbuffer data to an another surface (so it give a binary image of black & white).
In the second pass it draws the things normally.
Another thread is created to keep making the window transparency by reading that black & white surface, using the SetWindowRgn() function.
This is working perfectly, the only thing is it's not very good at making things transparent.
And the other issue is giving alpha blending to the drawn objects.
But you can easily set the total alpha (transparency) using the SetLayeredWindowAttributes() function.
Thanks for all the help you guys gave, all the things you guys told me was used and they guided me, as you can see. :)
The sad thing is we decided not to use this method because of efficiency problems :(
But I learned a lot of things, and it was an awesome experience. And that's all that matters to me :)
Thank You :)
You can make a hole in the parent window using SetWindowRgn.
Also, just because it is not your window doesn't mean you can't make it a layered window.
http://msdn.microsoft.com/en-us/library/ms997507.aspx
Finally, you can take control of another window by using subclassing - essentially you substitute your Wndproc in place of theirs, to handle the messages you wish to handle, then pass the remainder to their original wndproc.

Win32, C++: Creating a popup window without stealing focus

I am creating a program that displays a popup at certain times (just like some chat clients for example) on which the user can click. However, I do not want to take away the focus from the current application.
The way I'm doing it now is by using a HWND with WS_POPUPWINDOW and minimizing and then restoring the window. However, this steals the focus from the current application. Setting foreground or hiding and showing a window did not make it appear on the foreground. I would like to be able to keep using a HWND so I can use other elements in this window, but I have no idea how to give it foreground without stealing focus.
I use win32 and c++.
To show without activating:
ShowWindow(hwnd, SW_SHOWNOACTIVATE);
To raise without activating:
SetWindowPos(hwnd, HWND_TOP, 0, 0, 0, 0, SWP_NOMOVE|SWP_NOSIZE|SWP_NOACTIVATE);
Unfortunately this is not working for me. The window is created with CreateWindowExA and is showed using ShowWindow(hwnd, SW_SHOWNOACTIVATE) however the keyboard focus is still stolen from the window which has the focus at the moment of the creation. (The window is created with layered and trasparent attributes by using SetWindowLong() and SetLayeredWindowAttributes() ).
PS: The window which has the focus is not parent of the new created window.
Solved: It worked when I removed the SetForegroundWindow call. This function cause the window passed as parameter to be activated.