fix: scale cursor_position (#712)

* fix: scale cursor_position, closes #708

* adjust for wayland

* Add macOS fix

---------

Co-authored-by: Wu Wayne <[email protected]>

.changes/cursor-position-scale.md

@@ -0,0 +1,5 @@
+---
+"tao": "patch"
+---
+
+Fix `Window::cursor_position` and `EventLoopWindowTarget::cursor_position` scale on Linux and macOS.

src/event_loop.rs

@@ -248,7 +248,7 @@ impl<T> EventLoopWindowTarget<T> {
   ///
   /// ## Platform-specific
   ///
-  /// - **iOS / Android**: Unsupported.
+  /// - **iOS / Android / Linux(Wayland)**: Unsupported, returns `0,0`.
   #[inline]
   pub fn cursor_position(&self) -> Result<PhysicalPosition<f64>, ExternalError> {
     self.p.cursor_position()

src/platform_impl/linux/event_loop.rs

@@ -108,7 +108,7 @@ impl<T> EventLoopWindowTarget<T> {
 
   #[inline]
   pub fn cursor_position(&self) -> Result<PhysicalPosition<f64>, ExternalError> {
-    util::cursor_position()
+    util::cursor_position(self.is_wayland())
   }
 }
 

src/platform_impl/linux/util.rs

@@ -1,13 +1,29 @@
 use gdk::Display;
 
-use crate::{dpi::PhysicalPosition, error::ExternalError};
+use crate::{
+  dpi::{LogicalPosition, PhysicalPosition},
+  error::ExternalError,
+};
 
 #[inline]
-pub fn cursor_position() -> Result<PhysicalPosition<f64>, ExternalError> {
-  Display::default()
-    .and_then(|d| d.default_seat())
-    .and_then(|s| s.pointer())
-    .map(|p| p.position_double())
-    .map(|(_, x, y)| (x, y).into())
-    .ok_or(ExternalError::Os(os_error!(super::OsError)))
+pub fn cursor_position(is_wayland: bool) -> Result<PhysicalPosition<f64>, ExternalError> {
+  if is_wayland {
+    Ok((0, 0).into())
+  } else {
+    Display::default()
+      .map(|d| {
+        (
+          d.default_seat().and_then(|s| s.pointer()),
+          d.default_group(),
+        )
+      })
+      .map(|(p, g)| {
+        p.map(|p| {
+          let (_, x, y) = p.position_double();
+          LogicalPosition::new(x, y).to_physical(g.scale_factor() as _)
+        })
+      })
+      .map(|p| p.ok_or(ExternalError::Os(os_error!(super::OsError))))
+      .ok_or(ExternalError::Os(os_error!(super::OsError)))?
+  }
 }

src/platform_impl/linux/window.rs

@@ -761,7 +761,7 @@ impl Window {
 
   #[inline]
   pub fn cursor_position(&self) -> Result<PhysicalPosition<f64>, ExternalError> {
-    util::cursor_position()
+    util::cursor_position(self.window.display().backend().is_wayland())
   }
 
   pub fn current_monitor(&self) -> Option<RootMonitorHandle> {

src/platform_impl/macos/event_loop.rs

@@ -104,7 +104,12 @@ impl<T: 'static> EventLoopWindowTarget<T> {
 
   #[inline]
   pub fn cursor_position(&self) -> Result<PhysicalPosition<f64>, ExternalError> {
-    util::cursor_position()
+    let point = util::cursor_position()?;
+    if let Some(m) = self.monitor_from_point(point.x, point.y) {
+      Ok(point.to_physical(m.scale_factor()))
+    } else {
+      Err(ExternalError::Os(os_error!(super::OsError::CGError(0))))
+    }
   }
 }
 

src/platform_impl/macos/util/mod.rs

@@ -24,11 +24,7 @@ use core_graphics::{
 };
 use objc::runtime::{Class, Object, Sel, BOOL, YES};
 
-use crate::{
-  dpi::{LogicalPosition, PhysicalPosition},
-  error::ExternalError,
-  platform_impl::platform::ffi,
-};
+use crate::{dpi::LogicalPosition, error::ExternalError, platform_impl::platform::ffi};
 
 // Replace with `!` once stable
 #[derive(Debug)]
@@ -129,11 +125,11 @@ pub fn window_position(position: LogicalPosition<f64>) -> NSPoint {
 }
 
 // FIXME: This is actually logical position.
-pub fn cursor_position() -> Result<PhysicalPosition<f64>, ExternalError> {
+pub fn cursor_position() -> Result<LogicalPosition<f64>, ExternalError> {
   if let Ok(s) = CGEventSource::new(CGEventSourceStateID::CombinedSessionState) {
     if let Ok(e) = CGEvent::new(s) {
       let pt = e.location();
-      let pos = PhysicalPosition::new(pt.x, pt.y);
+      let pos = LogicalPosition::new(pt.x, pt.y);
       return Ok(pos);
     }
   }

src/platform_impl/macos/window.rs

@@ -805,7 +805,12 @@ impl UnownedWindow {
 
   #[inline]
   pub fn cursor_position(&self) -> Result<PhysicalPosition<f64>, ExternalError> {
-    util::cursor_position()
+    let point = util::cursor_position()?;
+    if let Some(m) = self.monitor_from_point(point.x, point.y) {
+      Ok(point.to_physical(m.scale_factor()))
+    } else {
+      Err(ExternalError::Os(os_error!(OsError::CGError(0))))
+    }
   }
 
   #[inline]

src/window.rs

@@ -1202,7 +1202,7 @@ impl Window {
   ///
   /// ## Platform-specific
   ///
-  /// - **iOS / Android**: Unsupported, returns `0,0`.
+  /// - **iOS / Android / Linux(Wayland)**: Unsupported, returns `0,0`.
   #[inline]
   pub fn cursor_position(&self) -> Result<PhysicalPosition<f64>, ExternalError> {
     self.window.cursor_position()