webdriver: Get the window position as well as the size when resolving "Get Window Rect" (#37812)

1. Rename `GetWindowSize` to `GetWindowRect`
2. Return the WindowRect in device pixels correctly. Previously, it
returns `(0, 0, ScreenWidth, ScreenHeight)` which is a static value.
3. Add `fn window_rect` to `WindowPortsMethods`. Implement it for both
Headless Window and Headed Window.

Testing: Tested manually with powershell script. Result is now dynamic
and reflects the truth.
Fixes: Task 1 & 2 of https://github.com/servo/servo/issues/37804

---------

Signed-off-by: Euclid Ye <yezhizhenjiakang@gmail.com>

components/constellation/constellation.rs

@@ -4534,7 +4534,7 @@ where
                 let is_open = self.browsing_contexts.contains_key(&browsing_context_id);
                 let _ = response_sender.send(is_open);
             },
-            WebDriverCommandMsg::GetWindowSize(..) => {
+            WebDriverCommandMsg::GetWindowRect(..) => {
                 unreachable!("This command should be send directly to the embedder.");
             },
             WebDriverCommandMsg::GetViewportSize(..) => {

components/shared/embedder/webdriver.rs

@@ -20,7 +20,7 @@ use servo_url::ServoUrl;
 use style_traits::CSSPixel;
 use webdriver::common::{WebElement, WebFrame, WebWindow};
 use webdriver::error::ErrorStatus;
-use webrender_api::units::{DeviceIntSize, DevicePixel};
+use webrender_api::units::{DeviceIntRect, DeviceIntSize, DevicePixel};
 
 use crate::{MouseButton, MouseButtonAction};
 
@@ -31,7 +31,7 @@ pub struct WebDriverMessageId(pub usize);
 #[derive(Debug, Deserialize, Serialize)]
 pub enum WebDriverCommandMsg {
     /// Get the window size.
-    GetWindowSize(WebViewId, IpcSender<Size2D<i32, DevicePixel>>),
+    GetWindowRect(WebViewId, IpcSender<DeviceIntRect>),
     /// Get the viewport size.
     GetViewportSize(WebViewId, IpcSender<Size2D<u32, DevicePixel>>),
     /// Load a URL in the top-level browsing context with the given ID.

components/webdriver_server/lib.rs

@@ -799,7 +799,7 @@ impl Handler {
     }
 
     /// <https://w3c.github.io/webdriver/#get-window-rect>
-    fn handle_window_size(
+    fn handle_window_rect(
         &self,
         verify: VerifyBrowsingContextIsOpen,
     ) -> WebDriverResult<WebDriverResponse> {
@@ -810,14 +810,14 @@ impl Handler {
         if let VerifyBrowsingContextIsOpen::Yes = verify {
             self.verify_top_level_browsing_context_is_open(webview_id)?;
         }
-        self.send_message_to_embedder(WebDriverCommandMsg::GetWindowSize(webview_id, sender))?;
+        self.send_message_to_embedder(WebDriverCommandMsg::GetWindowRect(webview_id, sender))?;
 
-        let window_size = wait_for_script_response(receiver)?;
+        let window_rect = wait_for_script_response(receiver)?;
         let window_size_response = WindowRectResponse {
-            x: 0,
+            x: window_rect.min.x,
-            y: 0,
+            y: window_rect.min.y,
-            width: window_size.width,
+            width: window_rect.width(),
-            height: window_size.height,
+            height: window_rect.height(),
         };
         Ok(WebDriverResponse::WindowRect(window_size_response))
     }
@@ -842,7 +842,7 @@ impl Handler {
         // We don't current allow modifying the window x/y positions, so we can just
         // return the current window rectangle if not changing dimension.
         if params.width.is_none() && params.height.is_none() {
-            return self.handle_window_size(VerifyBrowsingContextIsOpen::No);
+            return self.handle_window_rect(VerifyBrowsingContextIsOpen::No);
         }
         // (TODO) Step 14. Fully exit fullscreen.
         // (TODO) Step 15. Restore the window.
@@ -853,7 +853,7 @@ impl Handler {
 
         let current = LazyCell::new(|| {
             let WebDriverResponse::WindowRect(current) = self
-                .handle_window_size(VerifyBrowsingContextIsOpen::No)
+                .handle_window_rect(VerifyBrowsingContextIsOpen::No)
                 .unwrap()
             else {
                 unreachable!("handle_window_size() must return WindowRect");
@@ -2160,7 +2160,7 @@ impl WebDriverHandler<ServoExtensionRoute> for Handler {
             WebDriverCommand::Get(ref parameters) => self.handle_get(parameters),
             WebDriverCommand::GetCurrentUrl => self.handle_current_url(),
             WebDriverCommand::GetWindowRect => {
-                self.handle_window_size(VerifyBrowsingContextIsOpen::Yes)
+                self.handle_window_rect(VerifyBrowsingContextIsOpen::Yes)
             },
             WebDriverCommand::SetWindowRect(ref size) => self.handle_set_window_size(size),
             WebDriverCommand::IsEnabled(ref element) => self.handle_is_enabled(element),

ports/servoshell/desktop/app.rs

@@ -362,14 +362,14 @@ impl App {
                     // TODO: send a response to the WebDriver
                     // so it knows when the focus has finished.
                 },
-                WebDriverCommandMsg::GetWindowSize(_webview_id, response_sender) => {
+                WebDriverCommandMsg::GetWindowRect(_webview_id, response_sender) => {
                     let window = self
                         .windows
                         .values()
                         .next()
                         .expect("Should have at least one window in servoshell");
 
-                    if let Err(error) = response_sender.send(window.screen_geometry().size) {
+                    if let Err(error) = response_sender.send(window.window_rect()) {
                         warn!("Failed to send response of GetWindowSize: {error}");
                     }
                 },

ports/servoshell/desktop/headed_window.rs

@@ -17,7 +17,7 @@ use raw_window_handle::{HasDisplayHandle, HasWindowHandle, RawWindowHandle};
 use servo::servo_config::pref;
 use servo::servo_geometry::DeviceIndependentPixel;
 use servo::webrender_api::ScrollLocation;
-use servo::webrender_api::units::{DeviceIntPoint, DeviceIntSize, DevicePixel};
+use servo::webrender_api::units::{DeviceIntPoint, DeviceIntRect, DeviceIntSize, DevicePixel};
 use servo::{
     Cursor, ImeEvent, InputEvent, Key, KeyState, KeyboardEvent, MouseButton as ServoMouseButton,
     MouseButtonAction, MouseButtonEvent, MouseLeaveEvent, MouseMoveEvent,
@@ -483,6 +483,17 @@ impl WindowPortsMethods for Window {
             })
     }
 
+    fn window_rect(&self) -> DeviceIntRect {
+        let outer_size = self.winit_window.outer_size();
+        let total_size = Size2D::new(outer_size.width as i32, outer_size.height as i32);
+        let origin = self
+            .winit_window
+            .outer_position()
+            .map(|point| Point2D::new(point.x, point.y))
+            .unwrap_or_default();
+        DeviceIntRect::from_origin_and_size(origin, total_size)
+    }
+
     fn set_position(&self, point: DeviceIntPoint) {
         self.winit_window
             .set_outer_position::<PhysicalPosition<i32>>(PhysicalPosition::new(point.x, point.y))

ports/servoshell/desktop/headless_window.rs

@@ -8,9 +8,9 @@ use std::cell::Cell;
 use std::rc::Rc;
 
 use euclid::num::Zero;
-use euclid::{Length, Scale, Size2D};
+use euclid::{Length, Point2D, Scale, Size2D};
 use servo::servo_geometry::DeviceIndependentPixel;
-use servo::webrender_api::units::{DeviceIntSize, DevicePixel};
+use servo::webrender_api::units::{DeviceIntRect, DeviceIntSize, DevicePixel};
 use servo::{RenderingContext, ScreenGeometry, SoftwareRenderingContext};
 use winit::dpi::PhysicalSize;
 
@@ -135,6 +135,10 @@ impl WindowPortsMethods for Window {
         Length::zero()
     }
 
+    fn window_rect(&self) -> DeviceIntRect {
+        DeviceIntRect::from_origin_and_size(Point2D::zero(), self.inner_size.get())
+    }
+
     fn set_toolbar_height(&self, _height: Length<f32, DeviceIndependentPixel>) {
         unimplemented!("headless Window only")
     }

ports/servoshell/desktop/window_trait.rs

@@ -9,7 +9,7 @@ use std::rc::Rc;
 
 use euclid::{Length, Scale};
 use servo::servo_geometry::DeviceIndependentPixel;
-use servo::webrender_api::units::{DeviceIntPoint, DeviceIntSize, DevicePixel};
+use servo::webrender_api::units::{DeviceIntPoint, DeviceIntRect, DeviceIntSize, DevicePixel};
 use servo::{Cursor, RenderingContext, ScreenGeometry, WebView};
 
 use super::app_state::RunningAppState;
@@ -52,4 +52,5 @@ pub trait WindowPortsMethods {
     fn theme(&self) -> servo::Theme {
         servo::Theme::Light
     }
+    fn window_rect(&self) -> DeviceIntRect;
 }