collab ui: Fix notification windows on external monitors (#9817)

Sharing a project displays a notification (window) on every screen.
Previously there was an issue with the positioning of windows on all
screens except the primary screen.

As you can see here:


![image](https://github.com/zed-industries/zed/assets/53836821/314cf367-8c70-4e8e-bc4a-dcbb99cb4f71)

Now:


![image](https://github.com/zed-industries/zed/assets/53836821/42af9ef3-8af9-453a-ad95-147b5f9d90ba)

@mikayla-maki and I also decided to refactor the `WindowOptions` a bit. 
Previously you could specify bounds which controlled the positioning and
size of the window in the global coordinate space, while also providing
a display id (which screen to show the window on). This can lead to
unusual behavior because you could theoretically specify a global bound
which does not even belong to the display id which was provided.

Therefore we changed the api to this:
```rust
struct WindowOptions {
    /// The bounds of the window in screen coordinates
    /// None -> inherit, Some(bounds) -> set bounds.
    pub bounds: Option<Bounds<DevicePixels>>,

    /// The display to create the window on, if this is None,
    /// the window will be created on the main display
    pub display_id: Option<DisplayId>,
}
```

This lets you specify a display id, which maps to the screen where the
window should be created and bounds relative to the upper left of the
screen.

Release Notes:

- Fixed positioning of popup windows (e.g. when sharing a project) when
using multiple external displays.

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/gpui/src/platform/linux/wayland/display.rs

@@ -2,7 +2,7 @@ use std::fmt::Debug;
 
 use uuid::Uuid;
 
-use crate::{Bounds, DisplayId, GlobalPixels, PlatformDisplay, Size};
+use crate::{Bounds, DevicePixels, DisplayId, PlatformDisplay, Size};
 
 #[derive(Debug)]
 pub(crate) struct WaylandDisplay {}
@@ -19,12 +19,12 @@ impl PlatformDisplay for WaylandDisplay {
     }
 
     // todo(linux)
-    fn bounds(&self) -> Bounds<GlobalPixels> {
+    fn bounds(&self) -> Bounds<DevicePixels> {
         Bounds {
             origin: Default::default(),
             size: Size {
-                width: GlobalPixels(1000f32),
-                height: GlobalPixels(500f32),
+                width: DevicePixels(1000),
+                height: DevicePixels(500),
             },
         } // return some fake data so it doesn't panic
     }

crates/gpui/src/platform/linux/wayland/window.rs

@@ -22,7 +22,7 @@ use crate::platform::linux::wayland::display::WaylandDisplay;
 use crate::platform::{PlatformAtlas, PlatformInputHandler, PlatformWindow};
 use crate::scene::Scene;
 use crate::{
-    px, size, Bounds, GlobalPixels, Modifiers, Pixels, PlatformDisplay, PlatformInput, Point,
+    px, size, Bounds, DevicePixels, Modifiers, Pixels, PlatformDisplay, PlatformInput, Point,
     PromptLevel, Size, WindowAppearance, WindowParams,
 };
 
@@ -274,7 +274,7 @@ impl HasDisplayHandle for WaylandWindow {
 
 impl PlatformWindow for WaylandWindow {
     // todo(linux)
-    fn bounds(&self) -> Bounds<GlobalPixels> {
+    fn bounds(&self) -> Bounds<DevicePixels> {
         unimplemented!()
     }
 

crates/gpui/src/platform/linux/x11/display.rs

@@ -2,12 +2,12 @@ use anyhow::Result;
 use uuid::Uuid;
 use x11rb::{connection::Connection as _, xcb_ffi::XCBConnection};
 
-use crate::{Bounds, DisplayId, GlobalPixels, PlatformDisplay, Size};
+use crate::{Bounds, DevicePixels, DisplayId, PlatformDisplay, Size};
 
 #[derive(Debug)]
 pub(crate) struct X11Display {
     x_screen_index: usize,
-    bounds: Bounds<GlobalPixels>,
+    bounds: Bounds<DevicePixels>,
     uuid: Uuid,
 }
 
@@ -19,8 +19,8 @@ impl X11Display {
             bounds: Bounds {
                 origin: Default::default(),
                 size: Size {
-                    width: GlobalPixels(screen.width_in_pixels as f32),
-                    height: GlobalPixels(screen.height_in_pixels as f32),
+                    width: DevicePixels(screen.width_in_pixels as i32),
+                    height: DevicePixels(screen.height_in_pixels as i32),
                 },
             },
             uuid: Uuid::from_bytes([0; 16]),
@@ -37,7 +37,7 @@ impl PlatformDisplay for X11Display {
         Ok(self.uuid)
     }
 
-    fn bounds(&self) -> Bounds<GlobalPixels> {
+    fn bounds(&self) -> Bounds<DevicePixels> {
         self.bounds
     }
 }

crates/gpui/src/platform/linux/x11/window.rs

@@ -2,7 +2,7 @@
 #![allow(unused)]
 
 use crate::{
-    platform::blade::BladeRenderer, size, Bounds, GlobalPixels, Modifiers, Pixels, PlatformAtlas,
+    platform::blade::BladeRenderer, size, Bounds, DevicePixels, Modifiers, Pixels, PlatformAtlas,
     PlatformDisplay, PlatformInput, PlatformInputHandler, PlatformWindow, Point, PromptLevel,
     Scene, Size, WindowAppearance, WindowOptions, WindowParams,
 };
@@ -245,7 +245,7 @@ impl X11WindowState {
             x_window,
             callbacks: RefCell::new(Callbacks::default()),
             inner: RefCell::new(LinuxWindowInner {
-                bounds: params.bounds.map(|v| v.0 as i32),
+                bounds: params.bounds.map(|v| v.0),
                 scale_factor: 1.0,
                 renderer: BladeRenderer::new(gpu, gpu_extent),
                 input_handler: None,
@@ -325,12 +325,8 @@ impl X11WindowState {
 }
 
 impl PlatformWindow for X11Window {
-    fn bounds(&self) -> Bounds<GlobalPixels> {
-        self.0
-            .inner
-            .borrow_mut()
-            .bounds
-            .map(|v| GlobalPixels(v as f32))
+    fn bounds(&self) -> Bounds<DevicePixels> {
+        self.0.inner.borrow_mut().bounds.map(|v| v.into())
     }
 
     // todo(linux)