libservo: Create a WebViewBuilder class to construct WebViews (#36483)

This exposes a new method of creating `WebView`s using the Rust builder
pattern. This will be more important as we add more kinds of
configuration options for `WebView` such as size and HiDPI scaling.

Testing: The API currently doesn't have tests, but functionality is
ensured by the fact that servoshell is the test harness.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

components/servo/examples/winit_minimal.rs

@@ -7,7 +7,9 @@ use std::rc::Rc;
 
 use compositing::windowing::{EmbedderMethods, WindowMethods};
 use euclid::{Point2D, Scale, Size2D};
-use servo::{RenderingContext, Servo, TouchEventType, WebView, WindowRenderingContext};
+use servo::{
+    RenderingContext, Servo, TouchEventType, WebView, WebViewBuilder, WindowRenderingContext,
+};
 use servo_geometry::DeviceIndependentPixel;
 use tracing::warn;
 use url::Url;
@@ -53,8 +55,9 @@ impl ::servo::WebViewDelegate for AppState {
     }
 
     fn request_open_auxiliary_webview(&self, parent_webview: WebView) -> Option<WebView> {
-        let webview = self.servo.new_auxiliary_webview();
+        let webview = WebViewBuilder::new_auxiliary(&self.servo)
-        webview.set_delegate(parent_webview.delegate());
+            .delegate(parent_webview.delegate())
+            .build();
         webview.focus();
         webview.raise_to_top(true);
         self.webviews.borrow_mut().push(webview.clone());
@@ -115,8 +118,10 @@ impl ApplicationHandler<WakerEvent> for App {
             let url = Url::parse("https://demo.servo.org/experiments/twgl-tunnel/")
                 .expect("Guaranteed by argument");
 
-            let webview = app_state.servo.new_webview(url);
+            let webview = WebViewBuilder::new(&app_state.servo)
-            webview.set_delegate(app_state.clone());
+                .url(url)
+                .delegate(app_state.clone())
+                .build();
             webview.focus();
             webview.raise_to_top(true);
 

components/servo/lib.rs

@@ -119,7 +119,7 @@ pub use {bluetooth, bluetooth_traits};
 use crate::proxies::ConstellationProxy;
 use crate::responders::ServoErrorChannel;
 pub use crate::servo_delegate::{ServoDelegate, ServoError};
-pub use crate::webview::WebView;
+pub use crate::webview::{WebView, WebViewBuilder};
 pub use crate::webview_delegate::{
     AllowOrDenyRequest, AuthenticationRequest, FormControl, NavigationRequest, PermissionRequest,
     SelectElement, WebResourceLoad, WebViewDelegate,
@@ -661,29 +661,6 @@ impl Servo {
         self.compositor.borrow_mut().deinit();
     }
 
-    pub fn new_webview(&self, url: url::Url) -> WebView {
-        let webview = WebView::new(&self.constellation_proxy, self.compositor.clone());
-        self.webviews
-            .borrow_mut()
-            .insert(webview.id(), webview.weak_handle());
-        let viewport_details = self.compositor.borrow().default_webview_viewport_details();
-        self.constellation_proxy
-            .send(EmbedderToConstellationMessage::NewWebView(
-                url.into(),
-                webview.id(),
-                viewport_details,
-            ));
-        webview
-    }
-
-    pub fn new_auxiliary_webview(&self) -> WebView {
-        let webview = WebView::new(&self.constellation_proxy, self.compositor.clone());
-        self.webviews
-            .borrow_mut()
-            .insert(webview.id(), webview.weak_handle());
-        webview
-    }
-
     fn get_webview_handle(&self, id: WebViewId) -> Option<WebView> {
         self.webviews
             .borrow()

components/servo/webview.rs

@@ -20,9 +20,9 @@ use url::Url;
 use webrender_api::ScrollLocation;
 use webrender_api::units::{DeviceIntPoint, DeviceRect};
 
-use crate::ConstellationProxy;
 use crate::clipboard_delegate::{ClipboardDelegate, DefaultClipboardDelegate};
 use crate::webview_delegate::{DefaultWebViewDelegate, WebViewDelegate};
+use crate::{ConstellationProxy, Servo};
 
 /// A handle to a Servo webview. If you clone this handle, it does not create a new webview,
 /// but instead creates a new handle to the webview. Once the last handle is dropped, Servo
@@ -93,16 +93,15 @@ impl Drop for WebViewInner {
 }
 
 impl WebView {
-    pub(crate) fn new(
+    pub(crate) fn new(builder: WebViewBuilder) -> Self {
-        constellation_proxy: &ConstellationProxy,
-        compositor: Rc<RefCell<IOCompositor>>,
-    ) -> Self {
         let id = WebViewId::new();
+        let servo = builder.servo;
+
         let webview = Self(Rc::new(RefCell::new(WebViewInner {
             id,
-            constellation_proxy: constellation_proxy.clone(),
+            constellation_proxy: servo.constellation_proxy.clone(),
-            compositor: compositor.clone(),
+            compositor: servo.compositor.clone(),
-            delegate: Rc::new(DefaultWebViewDelegate),
+            delegate: builder.delegate,
             clipboard_delegate: Rc::new(DefaultClipboardDelegate),
             rect: DeviceRect::zero(),
             load_status: LoadStatus::Complete,
@@ -115,13 +114,35 @@ impl WebView {
             cursor: Cursor::Pointer,
         })));
 
-        compositor
+        builder
+            .servo
+            .compositor
             .borrow_mut()
             .add_webview(Box::new(ServoRendererWebView {
                 weak_handle: webview.weak_handle(),
                 id,
             }));
 
+        servo
+            .webviews
+            .borrow_mut()
+            .insert(webview.id(), webview.weak_handle());
+
+        if !builder.auxiliary {
+            let url = builder.url.unwrap_or(
+                Url::parse("about:blank").expect("Should always be able to parse 'about:blank'."),
+            );
+
+            let viewport_details = servo.compositor.borrow().default_webview_viewport_details();
+            servo
+                .constellation_proxy
+                .send(EmbedderToConstellationMessage::NewWebView(
+                    url.into(),
+                    webview.id(),
+                    viewport_details,
+                ));
+        }
+
         webview
     }
 
@@ -508,3 +529,41 @@ impl RendererWebView for ServoRendererWebView {
         }
     }
 }
+
+pub struct WebViewBuilder<'servo> {
+    servo: &'servo Servo,
+    delegate: Rc<dyn WebViewDelegate>,
+    auxiliary: bool,
+    url: Option<Url>,
+}
+
+impl<'servo> WebViewBuilder<'servo> {
+    pub fn new(servo: &'servo Servo) -> Self {
+        Self {
+            servo,
+            auxiliary: false,
+            url: None,
+            delegate: Rc::new(DefaultWebViewDelegate),
+        }
+    }
+
+    pub fn new_auxiliary(servo: &'servo Servo) -> Self {
+        let mut builder = Self::new(servo);
+        builder.auxiliary = true;
+        builder
+    }
+
+    pub fn delegate(mut self, delegate: Rc<dyn WebViewDelegate>) -> Self {
+        self.delegate = delegate;
+        self
+    }
+
+    pub fn url(mut self, url: Url) -> Self {
+        self.url = Some(url);
+        self
+    }
+
+    pub fn build(self) -> WebView {
+        WebView::new(self)
+    }
+}

ports/servoshell/desktop/app_state.rs

@@ -19,7 +19,7 @@ use servo::webrender_api::units::{DeviceIntPoint, DeviceIntRect, DeviceIntSize};
 use servo::{
     AllowOrDenyRequest, AuthenticationRequest, FilterPattern, FormControl, GamepadHapticEffectType,
     LoadStatus, PermissionRequest, Servo, ServoDelegate, ServoError, SimpleDialog, TouchEventType,
-    WebView, WebViewDelegate,
+    WebView, WebViewBuilder, WebViewDelegate,
 };
 use url::Url;
 
@@ -107,8 +107,10 @@ impl RunningAppState {
     }
 
     pub(crate) fn new_toplevel_webview(self: &Rc<Self>, url: Url) {
-        let webview = self.servo().new_webview(url);
+        let webview = WebViewBuilder::new(self.servo())
-        webview.set_delegate(self.clone());
+            .url(url)
+            .delegate(self.clone())
+            .build();
 
         webview.focus();
         webview.raise_to_top(true);
@@ -459,8 +461,9 @@ impl WebViewDelegate for RunningAppState {
         &self,
         parent_webview: servo::WebView,
     ) -> Option<servo::WebView> {
-        let webview = self.servo.new_auxiliary_webview();
+        let webview = WebViewBuilder::new_auxiliary(&self.servo)
-        webview.set_delegate(parent_webview.delegate());
+            .delegate(parent_webview.delegate())
+            .build();
 
         webview.focus();
         webview.raise_to_top(true);

ports/servoshell/egl/app_state.rs

@@ -21,8 +21,8 @@ use servo::{
     InputMethodType, Key, KeyState, KeyboardEvent, LoadStatus, MediaSessionActionType,
     MediaSessionEvent, MouseButton, MouseButtonAction, MouseButtonEvent, MouseMoveEvent,
     NavigationRequest, PermissionRequest, RenderingContext, ScreenGeometry, Servo, ServoDelegate,
-    ServoError, SimpleDialog, TouchEvent, TouchEventType, TouchId, WebView, WebViewDelegate,
+    ServoError, SimpleDialog, TouchEvent, TouchEventType, TouchId, WebView, WebViewBuilder,
-    WindowRenderingContext,
+    WebViewDelegate, WindowRenderingContext,
 };
 use url::Url;
 
@@ -211,10 +211,12 @@ impl WebViewDelegate for RunningAppState {
         }
     }
 
-    fn request_open_auxiliary_webview(&self, _parent_webview: WebView) -> Option<WebView> {
+    fn request_open_auxiliary_webview(&self, parent_webview: WebView) -> Option<WebView> {
-        let new_webview = self.servo.new_auxiliary_webview();
+        let webview = WebViewBuilder::new_auxiliary(&self.servo)
-        self.add(new_webview.clone());
+            .delegate(parent_webview.delegate())
-        Some(new_webview)
+            .build();
+        self.add(webview.clone());
+        Some(webview)
     }
 
     fn request_permission(&self, webview: WebView, request: PermissionRequest) {
@@ -309,8 +311,11 @@ impl RunningAppState {
     }
 
     pub(crate) fn new_toplevel_webview(self: &Rc<Self>, url: Url) {
-        let webview = self.servo.new_webview(url);
+        let webview = WebViewBuilder::new(&self.servo)
-        webview.set_delegate(self.clone());
+            .url(url)
+            .delegate(self.clone())
+            .build();
+
         webview.focus();
         self.add(webview.clone());
     }