I will try to explain my problem the best i can,
I'm creating a layered window in c++ (using windowsXP), all works fine until i drag my created window near the windows start button, and then when i press the star button of windows taskbar and close it again all the windows beneath of my layered window aren't being painted (only in the area of the start window that pops over my window).
My create window is like this:
CWnd::CreateEx( WS_EX_TOOLWINDOW |
WS_EX_LAYERED,
AfxRegisterWndClass(0),
lpstr_name, WS_POPUP, 0,0,0,0,
pc_parent->GetSafeHwnd(), 0);
...
When i create the window with this styles the problem ocurrs, but if i create with the extended style WS_EX_TRANSPARENT and all the others the problem does not occur any more. And if instead of a WS_POPUP window is a WS_CHILD or WS_OVERLAPPED then this also doesn't occur...
Can anyone please explain why when i create a WS_POPUP window with the WS_EX_LAYERED style all the beneath windows aren't updated, and if i add the style WS_EX_TRANSPARENT this works fine.
Note: why i do not use the WS_EX_TRANSPARENT style if it works right? if i use it then my window can not be dragged and i need it to do it :)
Updated:
alt text http://img17.imageshack.us/img17/586/clipboard01il.jpg
The image above is to describe better what is happening:
The first part of the image you can see my leyered window and beneath is the vs, in the second img i press the start button and then in the last image i already drag my layered window to the right and you can see that the vs window does not updates the affected area.
Note that this situation until now only occurs with the start window?! with other windows it does not happen!?...
Thanks
only in the area of the start window that pops over my window
That's expected. Only that clipping rectangle is obscured by the start menu so only that region will be repainted. What behavior are you expecting? If there are windows covered by more upper level windows, then they won't be repainted either -- why repaint something just to paint over it?
All underneath windows need to get repainted though if you use transparent because GDI can't calculate the final color of the pixel without knowing the area below the window's color.
Related
Can I remove or decorate the white border of the window top border
i use qt::customizewindowhint
It looks like you need a borderless window, reading the doc can help:
Produces a borderless window. The user cannot move or resize a borderless window via the window system. On X11, the result of the flag is dependent on the window manager and its ability to understand Motif and/or NETWM hints. Most existing modern window managers can handle this.
https://doc.qt.io/qt-5/qt.html#WindowType-enum
setWindowFlags(Qt::Window | Qt::FramelessWindowHint)
I'm having trouble drawing a button on top of a video with WinAPI. I am grabbing frames from the webcam and drawing those frames as soon as I get them. The problem is that whenever I draw an image the button disappears under it.
I tried using SetWindowPos(button, HWND_TOPMOST, 50, 50, 50, 50, SWP_SHOWWINDOW); to place the button at the topmost of the z-order but it still doesn't work.
The image is drawn on top of the button and this is a required behavior. I want the image to be as big as possible (taking the whole monitor).
I thought maybe I should make a part of the image transparent (the part over the button). Is that an easy solution and how should I go about doing that.
You can add WS_CLIPSIBLINGS style to the button ,
Clips child windows relative to each other; that is, when a particular
child window receives a WM_PAINT message, the WS_CLIPSIBLINGS style
clips all other overlapping child windows out of the region of the
child window to be updated. If WS_CLIPSIBLINGS is not specified and
child windows overlap, it is possible, when drawing within the client
area of a child window, to draw within the client area of a
neighboring child window.
Refer this case: https://stackoverflow.com/a/56470706/11128312
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.
In WTL, CBitmapButton does not support picture with transparent layer, like PNG.
so i customize the code to use GDI+ to draw PNG, name it as CPNGButton.
But things are strange on win XP.
When the button is overlaped by other window, the button receives WM_PAINT first, and then the parent, causing incorrect result.
--->
I check the resource and remove WS_TABSTOP attribute from the template of the button, things go ok,parent window receives WM_PAINT first, then the button.
What cause WS_TABSTOP to affect window painting order?
This is what happens when you don't draw the background. That leaves a 'hole' in the window, you see the pixels of whatever window is behind yours. Or the desktop if there is no such window. Not otherwise sure what this has to do with WS_TABSTOP.
Use the WS_EX_TRANSPARENT style flag. That tells Windows that you want the parent of the button to draw itself in the client window to provide the background pixels.
I seeking solution for Windows first.
I need to add visual effects to screen image without breaking the interactivity of all and every controls, that are on this screen.
The solution can be straightforward:
1. take a screenshot
2. show this screenshot in a separate window, above other windows
3. apply the effect to image, being shown on this window
But, this window (containing screenshot) makes any buttons and other controls below, unreachable for mouse interaction (clicking, hovering)
Is there any way to do this ?
From MSDN's documentation on layered windows...
"Hit testing of a layered window is based on the shape and transparency of the window. This means that the areas of the window that are color-keyed or whose alpha value is zero will let the mouse messages through. However, if the layered window has the WS_EX_TRANSPARENT extended window style, the shape of the layered window will be ignored and the mouse events will be passed to other windows underneath the layered window."
Here's an article about it. Notice this additional warning:
"setting the WS_EX_TRANSPARENT attribute affects the entire window: the user can't close the window using the 'x' button, select it with the mouse, or select any controls on the window. The application can still close the window programmatically."
Depending on what you're actually drawing and where, it might be more appropriate to use Owner-Drawn Controls rather than hover an "onion skin" over your whole window.