Reapply support for X11 screenshare (#28160)

Reapplies #27807 after [revert due to not building on
ARM](https://github.com/zed-industries/zed/pull/28141) by updating scap
to include [a fix to its build on
ARM](https://github.com/zed-industries/scap/commit/08f0a01417505cc0990b9931a37e5120db92e0d0)

Release Notes:

- N/A

---------

Co-authored-by: Marshall Bowers <git@maxdeviant.com>

crates/gpui/src/platform/linux/headless/client.rs

@@ -1,13 +1,16 @@
 use std::cell::RefCell;
 use std::rc::Rc;
 
+use anyhow::anyhow;
 use calloop::{EventLoop, LoopHandle};
-
+use futures::channel::oneshot;
 use util::ResultExt;
 
 use crate::platform::linux::LinuxClient;
 use crate::platform::{LinuxCommon, PlatformWindow};
-use crate::{AnyWindowHandle, CursorStyle, DisplayId, PlatformDisplay, WindowParams};
+use crate::{
+    AnyWindowHandle, CursorStyle, DisplayId, PlatformDisplay, ScreenCaptureSource, WindowParams,
+};
 
 pub struct HeadlessClientState {
     pub(crate) _loop_handle: LoopHandle<'static, HeadlessClient>,
@@ -63,6 +66,21 @@ impl LinuxClient for HeadlessClient {
         None
     }
 
+    fn is_screen_capture_supported(&self) -> bool {
+        false
+    }
+
+    fn screen_capture_sources(
+        &self,
+    ) -> oneshot::Receiver<anyhow::Result<Vec<Box<dyn ScreenCaptureSource>>>> {
+        let (mut tx, rx) = oneshot::channel();
+        tx.send(Err(anyhow!(
+            "Headless mode does not support screen capture."
+        )))
+        .ok();
+        rx
+    }
+
     fn active_window(&self) -> Option<AnyWindowHandle> {
         None
     }

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

@@ -28,6 +28,7 @@ use crate::{
     Pixels, Platform, PlatformDisplay, PlatformTextSystem, PlatformWindow, Point, Result,
     ScreenCaptureSource, Task, WindowAppearance, WindowParams, px,
 };
+
 #[cfg(any(feature = "wayland", feature = "x11"))]
 pub(crate) const SCROLL_LINES: f32 = 3.0;
 
@@ -50,6 +51,10 @@ pub trait LinuxClient {
     #[allow(unused)]
     fn display(&self, id: DisplayId) -> Option<Rc<dyn PlatformDisplay>>;
     fn primary_display(&self) -> Option<Rc<dyn PlatformDisplay>>;
+    fn is_screen_capture_supported(&self) -> bool;
+    fn screen_capture_sources(
+        &self,
+    ) -> oneshot::Receiver<Result<Vec<Box<dyn ScreenCaptureSource>>>>;
 
     fn open_window(
         &self,
@@ -230,12 +235,14 @@ impl<P: LinuxClient + 'static> Platform for P {
         self.displays()
     }
 
+    fn is_screen_capture_supported(&self) -> bool {
+        self.is_screen_capture_supported()
+    }
+
     fn screen_capture_sources(
         &self,
     ) -> oneshot::Receiver<Result<Vec<Box<dyn ScreenCaptureSource>>>> {
-        let (mut tx, rx) = oneshot::channel();
-        tx.send(Err(anyhow!("screen capture not implemented"))).ok();
-        rx
+        self.screen_capture_sources()
     }
 
     fn active_window(&self) -> Option<AnyWindowHandle> {

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

@@ -7,6 +7,7 @@ use std::{
     time::{Duration, Instant},
 };
 
+use anyhow::anyhow;
 use calloop::{
     EventLoop, LoopHandle,
     timer::{TimeoutAction, Timer},
@@ -14,7 +15,7 @@ use calloop::{
 use calloop_wayland_source::WaylandSource;
 use collections::HashMap;
 use filedescriptor::Pipe;
-
+use futures::channel::oneshot;
 use http_client::Url;
 use smallvec::SmallVec;
 use util::ResultExt;
@@ -85,7 +86,8 @@ use crate::{
     FileDropEvent, ForegroundExecutor, KeyDownEvent, KeyUpEvent, Keystroke, LinuxCommon, Modifiers,
     ModifiersChangedEvent, MouseButton, MouseDownEvent, MouseExitEvent, MouseMoveEvent,
     MouseUpEvent, NavigationDirection, Pixels, PlatformDisplay, PlatformInput, Point, SCROLL_LINES,
-    ScaledPixels, ScrollDelta, ScrollWheelEvent, Size, TouchPhase, WindowParams, point, px, size,
+    ScaledPixels, ScreenCaptureSource, ScrollDelta, ScrollWheelEvent, Size, TouchPhase,
+    WindowParams, point, px, size,
 };
 
 /// Used to convert evdev scancode to xkb scancode
@@ -633,6 +635,24 @@ impl LinuxClient for WaylandClient {
         None
     }
 
+    fn is_screen_capture_supported(&self) -> bool {
+        false
+    }
+
+    fn screen_capture_sources(
+        &self,
+    ) -> oneshot::Receiver<anyhow::Result<Vec<Box<dyn ScreenCaptureSource>>>> {
+        // TODO: Get screen capture working on wayland. Be sure to try window resizing as that may
+        // be tricky.
+        //
+        // start_scap_default_target_source()
+        let (sources_tx, sources_rx) = oneshot::channel();
+        sources_tx
+            .send(Err(anyhow!("Wayland screen capture not yet implemented.")))
+            .ok();
+        sources_rx
+    }
+
     fn open_window(
         &self,
         handle: AnyWindowHandle,

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

@@ -1,3 +1,4 @@
+use crate::platform::scap_screen_capture::scap_screen_sources;
 use core::str;
 use std::{
     cell::RefCell,
@@ -8,13 +9,13 @@ use std::{
     time::{Duration, Instant},
 };
 
+use anyhow::Context as _;
 use calloop::{
     EventLoop, LoopHandle, RegistrationToken,
     generic::{FdWrapper, Generic},
 };
-
-use anyhow::Context as _;
 use collections::HashMap;
+use futures::channel::oneshot;
 use http_client::Url;
 use smallvec::SmallVec;
 use util::ResultExt;
@@ -59,8 +60,8 @@ use crate::platform::{
 use crate::{
     AnyWindowHandle, Bounds, ClipboardItem, CursorStyle, DisplayId, FileDropEvent, Keystroke,
     Modifiers, ModifiersChangedEvent, MouseButton, Pixels, Platform, PlatformDisplay,
-    PlatformInput, Point, RequestFrameOptions, ScaledPixels, ScrollDelta, Size, TouchPhase,
-    WindowParams, X11Window, modifiers_from_xinput_info, point, px,
+    PlatformInput, Point, RequestFrameOptions, ScaledPixels, ScreenCaptureSource, ScrollDelta,
+    Size, TouchPhase, WindowParams, X11Window, modifiers_from_xinput_info, point, px,
 };
 
 /// Value for DeviceId parameters which selects all devices.
@@ -1327,6 +1328,16 @@ impl LinuxClient for X11Client {
         ))
     }
 
+    fn is_screen_capture_supported(&self) -> bool {
+        true
+    }
+
+    fn screen_capture_sources(
+        &self,
+    ) -> oneshot::Receiver<anyhow::Result<Vec<Box<dyn ScreenCaptureSource>>>> {
+        scap_screen_sources(&self.0.borrow().common.foreground_executor)
+    }
+
     fn open_window(
         &self,
         handle: AnyWindowHandle,