NSWindow keep in back of all windows/apps - macos

So not really sure how to even google search this question... But, I'd like to make an NSWindow, reside in the back of all other windows/apps & I want it to be displayed on every Mission Control space (still in the back).
I've seen other applications that do this, so I know it's possible, just don't know how.
(I'm referring to Lion's function called Mission Control where you can switch through different spaces.)

Found the answer, there's a method/enum to make it so that the window will appear in all "spaces" (mission control).
[self.window setCollectionBehavior:NSWindowCollectionBehaviorCanJoinAllSpaces];
And a method to keep the window to the farthest back possible.
[self.window setLevel:kCGDesktopIconWindowLevelKey - 1];
All you have to do is use these two methods, and it'll do exactly what I requested. However, I wish there was a way to keep it from animating when coming down from Mission control (there is non to my knowledge).

You want to set the NSWindow's level and collectionBehavior properties.
The window level you'll want to use will depend on what behavior you're after from your window. You can find constants for the available window levels in CoreGraphics/CGWindowLevel.h. I'd suggest trying CGWindowLevelForKey(kCGDesktopIconWindowLevelKey) ± 1.
Which collection behavior you specify will also depend on what behavior you're after. The brief description in your question suggests that NSWindowCollectionBehaviorStationary | NSWindowCollectionBehaviorCanJoinAllSpaces may be a good starting point.

Related

how to define window stacking order?

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.

How to find absolute value of caret position in pixels using Cocoa in MacOS?

For mouse I'm using:
ourEvent = CGEventCreate(None);
currentpos = CGEventGetLocation(ourEvent);
What can I use for the caret?
First the bad news.
Not every app is Cocoa-based, and those that are neither Cocoa nor Carbon nor a straight mix of the two—i.e., those based on wxWidgets, Qt, or some other cross-platform framework—typically reimplement the entire GUI stack on top of raw event and drawing primitives.
That means that there is typically no way to get this information from those applications (unless they're scriptable and expose it that way).
The good news is, Cocoa apps and some Carbon apps may expose this via Accessibility.
The user will need to have assistive devices turned on in System Preferences. Once that condition is met, you can use the Accessibility framework to get the frontmost application, get its focused window, get its focused view, and get its selection ranges.
A text view with an insertion point has exactly one selection range, and that range is empty (length=0). The location is where the insertion point is.
Of course, those are character indexes, not on-screen bounds.
That's where parameterized attributes come in. There's one for converting ranges to bounds. That's the one you want.
Theoretically (I haven't tried this), you should be able to convert the empty range of the insertion point to an empty or nearly-empty rectangle whose location is somewhere within the vertical line of the insertion point.
Make sure you test this with text views that are in scroll views, particularly when the insertion point is scrolled partially or completely out of view.
You'll want to use the Accessibility Inspector to see for yourself where your application will need to look, and to test individual applications and investigate reported failures.
You can get it from the Developer Downloads page, in the “Accessibility Tools” disk image.
If you want to focus a window, forging a mouse event to click on it is a bad idea—anything can happen if you click on the wrong thing. Send the window an kAXRaiseAction action instead.
If you want to set a text view's insertion point (and are looking to find where you need to forge a mouse event to click to set it in the desired position), again, that's a bad way to do it. Set the view's kAXSelectedTextRangesAttribute attribute instead. Again, an insertion point is a single empty range.
Did you try like this below?
NSPoint p=[[NSApp currentEvent]locationInWindow];
CGFloat X=p.x;
CGFloat Y=p.y;
NSLog(#"%f %f",X,Y);

How to add a NSColorPicker to the application's main window?

I'm building an application to generate an array of colors based on a color chosen by the user.
The default on Mac OS X for color selection is to open a NSColorPanel containing multiple NSColorPickers. But, as the color selection process is the main interaction the user will have with the app, it'd be better to avoid the extra clicks and panel-popping in favor of a more straightforward way.
So, is there any way to add a NSColorPicker object to a window?
I know this is an older question, but check out NSColorWell. From the docs:
NSColorWell is an NSControl for selecting and displaying a single color value.
Interresting Question.
I strongly doubt it (but would love to be proven wrong). NSColorPickers are not NSControls (nor NSCells) so there's no clean wrapper to insert into a window.
Even if you were to instanciate an NSColorPanel and get a reference to its contentView and copy it (with all that defines the color picking controls) to your own window... there's no obvious way of obtaining the color value. NSColorPickers are plug-ins so you can't forsee the controls of a colorPicker.
The only other way I can see (and that's a stretch) would be to manually load the NSColorPickers plug-ins directly. I don't know how successfull this would be.
File a bug report and request the feature?

What's the overhead of TPanel over TBevel

I'm working on a project where they essentially used TPanel for the only purpose of displaying a bevel (And maybe the design time convenience Panel have over Bevels).
Ok, I know TPanel is heavier than TBevel. Amongs other things, each TPanel create a user objects, which is a limited resource.
What I would like to know, beyond user objects, what's the overhead of TPanel? Is it next to non-existent (Especially on modern day machines).
If you were working on such a system, would you suggest :
Going back and changing all TPanel to TBevel.
Say "Ok it was bad. Lets not do it again in the future"
or
it's too small a concern and the design time convenience is well
worth it.
I wouldn't know if this design is intentional but, there's a slight navigational behavior difference when controls are grouped together in a window. If the focus is changed by arrow keys, after the one having the last tab order the first control will be focused (down/right), or vice-versa (up/left). IOW the focus will be wrapped in the parent. That's of course if any of the controls do not need the arrow keys.
Regarding the question, as it is already stated in the comments, apart from using up a count in an object pool, there're other resources associated with a window. It will also waste a few CPU cycles. There'll be one more level in the clipping chain or the messaging or keeping one more z-order list etc.. MSDN puts it as (I guess navigational aspect is being referred rather than visual partitioning):
For best performance, an application that needs to logically divide its main window should do so in the window procedure of the main window rather than by using child windows.
Nevertheless, as again already stated in the comments, most probably, no one will be able to tell the performance or resource difference caused by a few panels..
The correct answer is choice #3, so if that's the project's design approach, don't change it.

How to write an OS X application that can effect changes (custom cursor, draw an image) even when it is not active?

I previously asked a question about changing the cursor system-wide on OSX. I used NSCursor to change the cursor, but the effects are only as long as the application is active. When another application becomes active, the custom cursor is lost.
Here is a related, more general question. How can you write an application to have system-wife effects? For example drawing an image on-screen even when your application is not active, and something else is?
I understand I probably need to go at a lower level than the Cocoa APIs. I just cannot figure out where to start looking? Any specific Carbon APIs that I need to be looking at? Or even lower?
Any pointers would be appreciated! If you specifically know how to change the cursor system-wide or how to draw an image and move it around (no matter what application is active), that would solve my current problem as well! Can I write an application that can achieve this when its installed on the system?
Thanks!
You can achieve the effect you want, but not the way you're thinking about doing it.
You say,
I am writing a presentation aid application that shows the equivalent of the "laser pointer" on screen, programmatically. My first idea was to use the mouse cursor itself as the pointer, and change its appearance as a red circle.
Then fake that. Create an application, perhaps of type LSUIElement, perhaps not, depending on the behavior you want. Create a borderless window (type NSBorderlessWindowMask) and fill it with a clear color. Set its window level high enough so that it floats over everything (using -[NSWindow setLevel:], though I can't think of what the best level would be off-hand), and draw into it.
It's true that you cannot set the cursor when you are not the foremost app. It's true that you cannot just scribble on the screen. But you can get the same effects if you're clever.
This behaviour is not provided by any APIs on Mac OS X. You would have to modify the resource files in the OS, and that's a very dangerous operation that could brick the target computer. You have to know what you're doing.
Are you trying to implement a theming app or something like that? What's your goal? If you tell us what you are trying to do, we may be able to suggest alternate approaches.

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