I have a VS2008 C++ application for Windows XP SP3 developed using WTL 8.1. My application contains a tab control that flickers when the application border is resized.
My window hierarchy looks like this:
CFrameWindowImpl CMainFrm
|-CSplitterWindow Splitter
|-CTabView Configuration Tabs
| |-CDialogImpl Configuration View 1
| |-CDialogImpl Configuration View 2
| |-CDialogImpl Configuration View 3
|-CDialogImpl Control View
The solution I'm trying is to make the CFrameWindowImpl derived class use the WS_EX_COMPOSITED style and all windows beneath it use the WS_EX_TRANSPARENT style. Unfortunately, this makes the tab control buttons show as an empty black bar and the controls of any Configuration View to not show at all.
If I remove the WS_EX_COMPOSITED and WS_EX_TRANSPARENT styles, the form displays properly, but the CTabView and everything beneath it flickers horribly when resized.
What do I need to change to eliminate the flicker and draw the controls properly?
Thanks,
PaulH
Edit:
Got it working. I removed all the WS_EX_TRANSPARENT styles per Mark Ransom's suggestion. I put the WS_EX_COMPOSITED style on only the CTabCtrl (contained within the CTabView). Other controls get double-buffering as needed through WTL::CDoubleBufferImpl<>.
A window flickers because it gets erased before it's drawn. To eliminate this you need to disable erasing of the window entirely and use double buffering - draw the window contents into a bitmap, then copy the bitmap to the window. Because the bitmap contains the entire contents including the background, there's no need to erase anymore.
It looks like WS_EX_COMPOSITED will handle the double buffering automatically, but you still probably need to use a NULL background brush and/or handle the WM_ERASEBKGND message.
Whats not mentioned in MSDN is that the Desktop Window Manager - the component that hooks window painting on Windows Vista and 7 to perform the desktop composition necessary to get the aero glass effect - does NOT implement WS_EX_COMPOSITED.
Which means all the work you put into getting this style to work on XP, is doomed to become irrelevent on Vista or later.
The other problem with WS_EX_COMPOSITED - and why it was an optional style and not a default on XP: The double buffering only picks up painting performed during the BeginPaint / EndPaint block of the parent window. Lots of, even standard controls, perform painting outside of their WM_PAINT handlers, and as a result the backbuffer gets only partially painted.
Sadly, the result is, the only way to "eliminate" flicker in native API apps is to try to minimize it: WS_CLIPCHILDREN and WS_CLIPSIBLINGS can help if you dont have overlapping controls - to ensure that each control's area is painted only once. And ensure that the main dialog does not perform any flood filling in WM_ERASEBKGND
It is not, in my experience, possible to use double-buffering for anything that contains child controls (unless they all fully support WM_PRINT, which most do not).
Related
I am trying to create a Direct3D app that is operating in windowed mode with a title bar and minimize/quit button. However, I'd really like to be able to axe the border around the window.
I am looking to do this because it looks pretty cheesy on dual monitors when the app is filling the primary monitor horizontally (with room to move the app vertically), but its window border overflows onto the secondary screen. I've tried a bunch of combinations of setwindowlong with GWL_STYLE and GWL_EXSTYLE, but can't seem to make headway unless I disable the title bar.
I've seen a bunch of apps that are borderless however they seem to emulate the title bar rather than using the built in one provided by Microsoft.
Thanks for any suggestions.
You can't remove the border and keep the titlebar AFAIK.
You can reimplement the titlebar by using WM_NCHITTEST but you still need to draw it yourself which would not be a bad idea if you want your D3D app to look its best.
Visual Studio, last time I checked, achieves its border with transparent layered windows standing behind the primary one. They are the shadows you see.
This is a screenshot of Steam's client window being resized.
Steam's client window has two cool features.
Custom window which is very responsive.
Cool glass resize effect, different from standard windows (Thought it might be a side effect strongly related to 1)
Let's say I wanna create similar window using winapi. How can I do it?
I don't ask about widget-management related stuff, but about technical winapi tricks.
Basically, you can do almost anything with your window. But most of the tricks are to be implemented manually.
What is 'very responsive' I don't know. If you mean that the window has no standart border, it is easy to implement: do not specify WS_BORDER and WS_CAPTION when creating a WS_POPUP window. After that you will have to draw a border and a caption yourself. Handle WM_ERASEBKGND and WM_PAINT messages, draw background, menus, all as usual.
This effect seems to me more like a bug. It happens this way: the window is resized, it gets a WM_SIZE message, processes it, Windows sends a WM_ERASEBKGND message which the window ignores. Thus, the system draws a new shadow around new window frame which is not yet filled with new window image. And here we get this cool glass effect: old image of underlaying windows with a windows aero shadow. You can try to disable windows shadows and look at this effect.
In order to create a custom resizing border, you might find useful these functions: LoadCursor, SetCursor, MoveWindow.
In order to draw your custom borders, you can use standart GDI functions. Also you can create a handful of child windows and delegate drawing to them. This is basics of winapi.
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.
Group boxes don't render properly if the parent window has the WS_CLIPCHILDREN style set. My current workaround is to simply remove the flag from the parent. However this results in extreme flickering when resizing the window.
Is there a better workaround possible?
Update
The Dr Dobbs article Resizable Dialogs Revisited address exactly the same problem that I am experiencing. The solution offered reduces flashing, but doesn't eliminate it. I'll be using this code. However if better solutions would be possible, then feel free to post them!
Don't use group boxes.
Group boxes only make sense in layouts where controls are going to be overlapped - which styles like WS_CLIBSIBLINGS | WS_CLIPCHILDREN only make sense in layouts where there is NO control overlap.
The only way to get overlapping controls to work flicker free would be to actually make the grouped controls children of the group box. Then they'd be clipped out of its area when it paints.
Microsoft added a style to Windows 2000 to fix this issue: WS_EX_COMPOSITED that forces a bottom to top paint order on child controls and paints everything in the context of the parent windows WM_PAINT message - but they promptly broke that style with Windows Vista and 7 - WS_EX_COMPOSITED only works now if aero glass is disabled. Ew.
I have tried several methods, but problems always exist. Sometimes the sub-window didn't refresh and sometimes the sub-window will keep blink.
This is a sample project that i have written
http://rapidshare.com/files/283950611/TestProject.7z.html
My method to implement that is:
Put a scroll bar on the top of sub-window, whenever the scroll bar was dragged, the sub-window would be moved as well.
And every dialog is inherited from CDialogBase, All the drawing is done in this class, Drawer.h is a helper for drawing.
Only when the DC that user assigned is dirty, then system will redraw the window, it is used for accelerating the painting.
WS_EX_LAYERED only can be added to with top level window, not sub-window; I've tried to modify the window style from WS_CHILD to WS_OVERLAPPED, and then using layed window, and then clip the visiable area of the window, but, the result is not what I expected.
Anywhere, thank you for your advice...
Have you considered using WS_EX_LAYERED and then using UpdateLayeredWindow. It can get quite complicated but allows for things like per-pixel alpha and eliminates flicker like you are seeing.
Look here:
http://www.nuonsoft.com/blog/2009/05/27/how-to-use-updatelayeredwindow/
for more info.