One of our applications duplicates an area in the top left corner of the monitor and displays it to the public. Any of our other applications are prevented from covering this area, you cannot drag any of them over this area (they hit a "wall"), otherwise they would be visible publicly. However, if a user starts another application, say IE, it can display over the restricted area. Is there a registry setting or something that we can set that will prevent ALL applications from using this part of the desktop, eg. 300x200. I could set this value when our program starts and restore it when it closes, and have a separate application just to restore it just in case! It is not a serious limitation if the whole of the side or top could not be used, ie. if we block out the whole first 300 pixels on the left this would be acceptable. We are running W7-10 depending on the customer, programming is done in Delphi XE (at the moment).
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For a small demonstration application, I want the option to delete file (from the files explorer on windows) by simple dragging it all the way to left/right side of the screen (the all desktop, not the application)
Is there a way to do it?
Thanks.
For demonstration purposes you could create a borderless always on top window that fills the entire screen and cut out a hole in the middle of it with a window region so you are left with just a 1 or 2 pixel wide strip on each side and set the opacity to 1 so it is basically invisible. You could then handle drops on the window.
On Windows 8 you might run into issues because it already uses the edges.
I don't believe this feature is useful enough to actually implement as a real product though.
I'm trying to write my own window manager. One issue I faced is that I don't understand how to define in which order windows should be displayed. The only means I found is to use xcb_configure_window. But it looks very limited to me: it only allows either to rise the window on top of all, or put it to the very bottom (no notion of layers or something). What a limited functionality :(.
What I really would like to do is to define the window order and tell X about it. Or to define multiple layers of windows (e.g, normal, above all, below all). So I could rise (or lower) the window with respect to its layer. So windows from lower layers will not ever cover windows from upper layers.
So, is there any other library function to define the order of windows apart from xcb_configure_window? Or I need to live with it? That would mean I have to track the order of windows in my window manager.
Link to relevant XCB documentation: https://www.x.org/releases/X11R7.6/doc/libxcb/tutorial/index.html#winstack
X11 only gives you the absolute minimum. There are no layers or always-over or always-under windows. You implement all the fancy stuff yourself, typically in the window manager, which is what you are writing.
There is no raw protocol request to change the stacking order of windows at once. Xlib has a function XRestackWindows which does that, but it uses one configure request per window. The pseudocode is just
for each window in the list except the first
change the stacking order to be under the previous window
That's it. Nothing more fancy than that.
You do need to track the stacking order in your WM in order to implement layers, so that when a program tries to restack a top level window, you intercept the request and only restack it within its layer.
Another possible way to implement layers is to have several transparent full-screen windows and reparent users' top-level windows to those, instead of to the root window. I'm not totally sure it will always work though, and you need to deal with transparency in one way or another, which requires transparency supporting hardware or the composite extension or possibly both.
It is the responsibility of the window manager to order the windows. A window gives hints about which type it is (popup dialog, menu window, splashscreen, toolbox, etc), the window manager then decides how to display this on the screen. This includes keeping track of the order and deciding which gets priority.
There is a X11 call to change the order (XRestackWindows), but I don't know the Xcb equivalent.
I develop audio plugins, which are run inside their hosts and work realtime. Each plugin has its own window with controls, which often contains some kind of analysis pane, a pretty big rectangle that gets repeatedly painted (e.g. 20-50x per second). This is all working well.
The trouble comes when the user adjusts a parameter - the plugin uses WM_MOUSEMOVE to track mouse movements and on each change calls ::InvalidateRect to make the relevant portion of the window be redrawn. If you move quickly enough, the window really gets quickly repainted, however there seems no time for the host and other windows to be redrawn and these usually perform some kind of analysis feedback too, so it is really not ideal.
No my questions:
1) Assuming the host and other window are using ::InvalidateRect too, why mine is prioritized?
2) How to make ::InvalidateRect not prioritized, meaning the window needs to be invalidated, but it may be later, the rest of the system must get time for their redrawing too.
Thanks in advance!
It is possible to use the SetWindowPos API on Windows to keep a windows always on top of other windows, and there are many questions on StackOverflow dealing with this.
It is possible to keep only part of a Window always visible? I.e. specify a clipping region inside an existing window, and keep only that part visible?
A use case would be the following (on Windows):
User clicks on icon to run app.
User highlights a portion of the screen to focus on (similar to the Snipping Tool on Windows 7)
The highlighted part of the screen remains always visible, even when other windows/programs are moved over the selected region.
I know the issues that would spring up with having other applications that are also set to being topmost. Just curious if this is even possible?
Even if you change part of your window to be transparent to what's below (with a clipping region) it's still going to take all the mouse clicks, etc. that occur over the transparent part.
Your best bet is to create a new smaller window and make it top-most while hiding the main one.
My application is a Windows Forms one.
I tried using the windows wallpaper, but this depends on the "Fill", "Stretch", "Fit" or "Tile" settings.
I just need the image as it is on the desktop, but including the part "under" the taskbar, because this part is visible in case of transparent taskbar.
Why I need this?
Because I have a tray application which slides from under the taskbar when opening. And I need to set a mask there, so it can't be seen sliding, until it reaches the top of the taskbar. Again, this is only a problem when the taskbar is transparent.
I am not sure if I understood your question correctly. But to me, it seems that you need the image that has created wallpaper. If it seems easier, take a look at registry entries at following location:
HKEY_CURRENT_USER\Control Panel\Desktop
This will give you the path, size, tile/no tile etc. information for the wallpaper.
There is a Win32 function called PaintDesktop you could try but unless I'm misunderstanding things you should be able to just adjust the height of your window so it is never really behind the taskbar...
Why I need this? Because I have a tray application which slides from under the taskbar when opening. And I need to set a mask there, so it can't be seen sliding, until it reaches the top of the taskbar. Again, this is only a problem when the taskbar is transparent.
The problem here is that you're starting the slide up from the bottom of the entire screen, rather than starting from the bottom of the screen's working area (i.e., the top of the taskbar). That's why you're seeing the pop-up window slide up behind a transparent taskbar.
Luckily, the solution is much simpler than obtaining the desktop background and/or doing any type of masking. It's also much faster, and it's always good that your eye candy isn't unnecessarily taxing the user's computer.
All you need to do is determine the coordinates of the screen's working area, which is defined by Windows as the area that can be used by applications, not including the taskbar and other side bars. You can obtain this information easily in WinForms by querying the Screen.PrimaryScreen.WorkingArea property. This will return a Rectangle that corresponds to the primary screen's working area. Since you know that the taskbar is always displayed on the primary screen, this is exactly what you want.
Once you have the coordinates of the primary screen's working area, start your pop-up window's slide from the bottom of that.*
This is a good lesson of why you should always include an explanation of why you want to accomplish something. There's often an even better way that you haven't thought of.
*Of course, I'm ignoring the fact that a user might not have their taskbar positioned at the bottom of the screen. You can put it on either side or even on top. It sounds to me like you haven't considered this in your question, either. If this is an app that you're writing only for yourself or for a controlled environment where you can be sure that no one has their taskbar in non-default positions, that might be OK. But if you're writing software to distribute to a wider audience, you will need to take this into account. The rcWork coordinates will be correct, regardless of where the taskbar is positioned, of course, but you will need to know whether to start the pop-up window's slide from the bottom, the left side, the right side, or the top.