libservo: Make zooming and HiDPI scaling work per-`WebView` (#36419)

libservo: Make zooming and HiDPI scaling work per-`WebView`

This change moves all zooming and HiDPI scaling to work per-`WebView` in
both libservo and Compositor. This means that you can pinch zoom one
`WebView` and it should now work independently of other `WebView`s.
This is accomplished by making each `WebView` in the WebRender scene
have its own scaling reference frame.

All WebViews are now expected to manage their HiDPI scaling factor and
this can be set independently of other WebViews. Perhaps in the future
this will become a Servo-wide setting.

This allows full removal of the `WindowMethods` trait from Servo.

Testing: There are not yet any tests for the WebView API, but I hope
to add those soon.

Co-authored-by: Shubham Gupta <shubham13297@gmail.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Shubham Gupta <shubham13297@gmail.com>

1 files changed, 5 insertions, 22 deletions

diff --git a/components/servo/lib.rs b/components/servo/lib.rs
index f6ac0cd2f9e..642cff60cb0 100644
--- a/components/servo/lib.rs
+++ b/components/servo/lib.rs
@@ -42,7 +42,7 @@ use canvas::WebGLComm;
 use canvas::canvas_paint_thread::CanvasPaintThread;
 use canvas_traits::webgl::{GlType, WebGLThreads};
 use clipboard_delegate::StringRequest;
-use compositing::windowing::{EmbedderMethods, WindowMethods};
+use compositing::windowing::EmbedderMethods;
 use compositing::{IOCompositor, InitialCompositorState};
 pub use compositing_traits::rendering_context::{
     OffscreenRenderingContext, RenderingContext, SoftwareRenderingContext, WindowRenderingContext,
@@ -186,11 +186,8 @@ mod media_platform {
 /// orchestrating the interaction between JavaScript, CSS layout,
 /// rendering, and the client window.
 ///
-/// Clients create a `Servo` instance for a given reference-counted type
-/// implementing `WindowMethods`, which is the bridge to whatever
-/// application Servo is embedded in. Clients then create an event
-/// loop to pump messages between the embedding application and
-/// various browser components.
+// Clients create an event loop to pump messages between the embedding
+// application and various browser components.
 pub struct Servo {
     delegate: RefCell<Rc<dyn ServoDelegate>>,
     compositor: Rc<RefCell<IOCompositor>>,
@@ -250,7 +247,7 @@ impl Servo {
     #[cfg_attr(
         feature = "tracing",
         tracing::instrument(
-            skip(preferences, rendering_context, embedder, window),
+            skip(preferences, rendering_context, embedder),
             fields(servo_profiling = true),
             level = "trace",
         )
@@ -260,7 +257,6 @@ impl Servo {
         preferences: Preferences,
         rendering_context: Rc<dyn RenderingContext>,
         mut embedder: Box<dyn EmbedderMethods>,
-        window: Rc<dyn WindowMethods>,
         user_content_manager: UserContentManager,
     ) -> Self {
         // Global configuration options, parsed from the command line.
@@ -484,7 +480,6 @@ impl Servo {
         // rendered page and display it somewhere.
         let shutdown_state = Rc::new(Cell::new(ShutdownState::NotShuttingDown));
         let compositor = IOCompositor::new(
-            window,
             InitialCompositorState {
                 sender: compositor_proxy,
                 receiver: compositor_receiver,
@@ -625,10 +620,6 @@ impl Servo {
             .retain(|_webview_id, webview| webview.strong_count() > 0);
     }
 
-    pub fn pinch_zoom_level(&self) -> f32 {
-        self.compositor.borrow_mut().pinch_zoom_level().get()
-    }
-
     pub fn setup_logging(&self) {
         let constellation_chan = self.constellation_proxy.sender();
         let env = env_logger::Env::default();
@@ -724,15 +715,7 @@ impl Servo {
                     let webview_id_and_viewport_details = webview
                         .delegate()
                         .request_open_auxiliary_webview(webview)
-                        .map(|webview| {
-                            let mut viewport =
-                                self.compositor.borrow().default_webview_viewport_details();
-                            let rect = webview.rect();
-                            if !rect.is_empty() {
-                                viewport.size = rect.size() / viewport.hidpi_scale_factor;
-                            }
-                            (webview.id(), viewport)
-                        });
+                        .map(|webview| (webview.id(), webview.viewport_details()));
                     let _ = response_sender.send(webview_id_and_viewport_details);
                 }
             },