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.
Related
I have a LayeredWindow GUI that contains some child's and all of them contains the WS_EX_TRANSPARENT style.
The style is used to be able to remove their background.
When i move the mouse over the GUI only the LayeredWindow receives the message WM_MOUSEMOVE.
I tried calling ChildWindowFromPointEx using the XY pos got from the WM_MOUSEMOVE lParam
to detect the control being hovered, but the API didn't recognize any of the controls belonging to the child GUI's.
Docs says:
The search is restricted to immediate child windows. Grandchildren and deeper descendants are not searched.
The other option i tried was EnumChildWindow and compare each control rect to the XY position of the message, this method is using around 1% of CPU only from moving the mouse.
I wonder if there's any 'better' option?
According to the Doc: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.
You could try to use GetCursorPos function to get the position of the mouse cursor, in screen coordinates.
I must find the coordinates of a point which is out of the application window.
I intend to have a button "Specify Point" and when the user clicks this button, their next mouseclick will be registered by the program as this desired point. The problem is I don't know how to implement this....Any ideas ?
You can call SetCapture to direct mouse clicks from anywhere on the desktop to your window. Call ReleaseCapture after the click to return to normal.
If the user clicks on another application you will receive the click but the other application will also be activated, which you probably don't want. To avoid this, an alternative approach is to overlay the entire desktop with an always-on-top very nearly fully transparent window (a fully transparent window won't get clicks). Transparent windows are known as layered windows; use the WS_EX_LAYERED extended style to create one.
I need to draw an icon that moves approximately in sync with mouse cursor and is always on top of all windows.
OS: Windows 7
I have a solutions that work to some extend by drawing my icon in a top most transparent window. There are some major drawbacks in this solution since that top most window interferes with other top most windows and some full screen apps do not work correctly. Examples are start menu and task bar that will overlay my window if I do not regulary set it to be top most. For some full screen applications performance of updating position of window with icon hugely drops and it does not follow mouse smoothly.
There is another method that I came across where an icon is drawn directly to the device context of desktop Draw mouse pointer icon?. This solution has a drawback that there seems to be no good way of how to remove "trail", especially if desktop content changes quickly.
So my question: is there an ultimate solution that does not have the above mentioned problems?
Is it possible to draw above all windows in the "layer" of mouse cursor? Or make a second mouse cursor with my custom icon that I will control (I know that widows can display two independently controlled mouse cursors like CPNMouse)?
Can someone point me to the right direction?
Thanks!
Use a top-most window with transparency set via WS_EX_LAYERED / UpdateLayeredWindow.
If you set the WS_EX_TRANSPARENT style as well then the window won't intercept mouse input.
I have a transparent window (created with WS_EX_LAYERED) and I'd like to receive mouse events of the zero-alpha regions.
As far as I know, I could:
1) Use mouse hook
2) Paint the background with almost completely transparent color (that has an opacity of 1)
However, the first solution is time consuming and the 2nd one will slow my rendering time as my window is stretched almost all over the desktop and most of the pixels are completely transparent at the moment.
Is there another way receiving those mouse events?
According to MSDN:
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.
However, in a new thread you could get continuously the coordinates of the mouse with GetCursorPos and if the position is inside one of your icons (regardless, that it's over a zero alpha pixel inside the icon) you handle it. Not too much better than the hook
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.