Allow using IPC to handle navigations

Cargo.toml

@@ -5,6 +5,7 @@ members = ["verso", "versoview_messages"]
 ipc-channel = "0.19"
 serde = { version = "1.0", features = ["derive"] }
 url = { version = "2.5.2", features = ["serde"] }
+log = "0.4"
 
 [package]
 name = "versoview"
@@ -63,7 +64,7 @@ glutin = "0.32.0"
 glutin-winit = "0.5.0"
 ipc-channel = { workspace = true }
 keyboard-types = "0.7"
-log = "0.4"
+log = { workspace = true }
 raw-window-handle = { version = "0.6", features = ["std"] }
 sparkle = "0.1.26"
 thiserror = "1.0"

src/errors.rs

@@ -14,4 +14,7 @@ pub enum Error {
     /// Glutin errors.
     #[error(transparent)]
     GlutinError(#[from] glutin::error::Error),
+    /// IPC errors.
+    #[error(transparent)]
+    IpcError(#[from] ipc_channel::ipc::IpcError),
 }

src/verso.rs

@@ -581,6 +581,16 @@ impl Verso {
                     );
                 }
             }
+            ControllerMessage::OnNavigationStarting(sender) => {
+                if let Some((window, _)) = self.windows.values().next() {
+                    window
+                        .event_listeners
+                        .on_navigation_starting
+                        .lock()
+                        .unwrap()
+                        .replace(sender);
+                }
+            }
             _ => {}
         }
     }

src/webview.rs

@@ -83,9 +83,15 @@ impl Window {
                 self.window.request_redraw();
                 send_to_constellation(sender, ConstellationMsg::FocusWebView(webview_id));
             }
-            EmbedderMsg::AllowNavigationRequest(id, _url) => {
-                // TODO should provide a API for users to check url
-                send_to_constellation(sender, ConstellationMsg::AllowNavigationResponse(id, true));
+            EmbedderMsg::AllowNavigationRequest(id, url) => {
+                let allow = match self.allow_navigation(url) {
+                    Ok(allow) => allow,
+                    Err(e) => {
+                        log::error!("Error when calling navigation handler: {e}");
+                        true
+                    }
+                };
+                send_to_constellation(sender, ConstellationMsg::AllowNavigationResponse(id, allow));
             }
             EmbedderMsg::GetClipboardContents(sender) => {
                 let contents = clipboard
@@ -286,4 +292,18 @@ impl Window {
         }
         false
     }
+
+    fn allow_navigation(&self, url: ServoUrl) -> crate::Result<bool> {
+        if let Some(ref sender) = *self.event_listeners.on_navigation_starting.lock().unwrap() {
+            let (result_sender, receiver) =
+                ipc::channel::<bool>().map_err(|e| ipc::IpcError::Io(e))?;
+            sender
+                .send((url.into_url(), result_sender))
+                .map_err(|e| ipc::IpcError::Bincode(e))?;
+            let result = receiver.recv()?;
+            Ok(result)
+        } else {
+            Ok(true)
+        }
+    }
 }

src/window.rs

@@ -1,4 +1,4 @@
-use std::cell::Cell;
+use std::{cell::Cell, sync::Mutex};
 
 use base::id::WebViewId;
 use compositing_traits::ConstellationMsg;
@@ -12,6 +12,7 @@ use glutin::{
 use glutin_winit::DisplayBuilder;
 use script_traits::{TouchEventType, WheelDelta, WheelMode};
 use servo_url::ServoUrl;
+use versoview_messages::OnNavigationStartingPayload;
 use webrender_api::{
     units::{DeviceIntPoint, DeviceIntRect, DeviceIntSize, DevicePoint, LayoutVector2D},
     ScrollLocation,
@@ -36,6 +37,11 @@ use crate::{
 
 use arboard::Clipboard;
 
+#[derive(Default)]
+pub(crate) struct EventListeners {
+    pub(crate) on_navigation_starting: Mutex<Option<OnNavigationStartingPayload>>,
+}
+
 /// A Verso window is a Winit window containing several web views.
 pub struct Window {
     /// Access to Winit window
@@ -46,6 +52,8 @@ pub struct Window {
     pub(crate) panel: Option<Panel>,
     /// The WebView of this window.
     pub(crate) webview: Option<WebView>,
+    /// Event listeners registered from the webview controller
+    pub(crate) event_listeners: EventListeners,
     /// The mouse physical position in the web view.
     mouse_position: Cell<Option<PhysicalPosition<f64>>>,
     /// Modifiers state of the keyboard.
@@ -94,6 +102,7 @@ impl Window {
                 surface,
                 panel: None,
                 webview: None,
+                event_listeners: Default::default(),
                 mouse_position: Default::default(),
                 modifiers_state: Cell::new(ModifiersState::default()),
                 resizing: false,
@@ -131,6 +140,7 @@ impl Window {
             surface,
             panel: None,
             webview: None,
+            event_listeners: Default::default(),
             mouse_position: Default::default(),
             modifiers_state: Cell::new(ModifiersState::default()),
             resizing: false,

verso/Cargo.toml

@@ -7,4 +7,5 @@ edition = "2021"
 ipc-channel = { workspace = true }
 serde = { workspace = true }
 url = { workspace = true }
+log = { workspace = true }
 versoview_messages = { path = "../versoview_messages" }

verso/src/lib.rs

@@ -1,9 +1,25 @@
-use std::{path::Path, process::Command};
+use log::error;
+use std::{
+    path::Path,
+    process::Command,
+    sync::{Arc, Mutex},
+};
 use versoview_messages::ControllerMessage;
 
-use ipc_channel::ipc::{IpcOneShotServer, IpcSender};
+use ipc_channel::{
+    ipc::{self, IpcOneShotServer, IpcSender},
+    router::ROUTER,
+};
 
-pub struct VersoviewController(IpcSender<ControllerMessage>);
+#[derive(Default)]
+struct EventListeners {
+    on_navigation_starting: Arc<Mutex<Option<Box<dyn Fn(url::Url) -> bool + Send + 'static>>>>,
+}
+
+pub struct VersoviewController {
+    sender: IpcSender<ControllerMessage>,
+    event_listeners: EventListeners,
+}
 
 impl VersoviewController {
     /// Create a new verso instance and get the controller to it
@@ -17,11 +33,48 @@ impl VersoviewController {
             .spawn()
             .unwrap();
         let (_, sender) = server.accept().unwrap();
-        Self(sender)
+        Self {
+            sender,
+            event_listeners: EventListeners::default(),
+        }
     }
 
     /// Navigate to url
     pub fn navigate(&self, url: url::Url) -> Result<(), Box<ipc_channel::ErrorKind>> {
-        self.0.send(ControllerMessage::NavigateTo(url))
+        self.sender.send(ControllerMessage::NavigateTo(url))
+    }
+
+    /// Listen on navigation starting triggered by user click on a link,
+    /// return a boolean in the callback to decide whether or not allowing this navigation
+    pub fn on_navigation_starting(
+        &self,
+        callback: impl Fn(url::Url) -> bool + Send + 'static,
+    ) -> Result<(), Box<ipc_channel::ErrorKind>> {
+        if self
+            .event_listeners
+            .on_navigation_starting
+            .lock()
+            .unwrap()
+            .replace(Box::new(callback))
+            .is_some()
+        {
+            return Ok(());
+        }
+        let cb = self.event_listeners.on_navigation_starting.clone();
+        let (sender, receiver) = ipc::channel::<(url::Url, ipc::IpcSender<bool>)>()?;
+        self.sender
+            .send(ControllerMessage::OnNavigationStarting(sender))?;
+        ROUTER.add_typed_route(
+            receiver,
+            Box::new(move |message| match message {
+                Ok((url, result_sender)) => {
+                    if let Err(e) = result_sender.send(cb.lock().unwrap().as_ref().unwrap()(url)) {
+                        error!("Error while sending back OnNavigationStarting result: {e}");
+                    }
+                }
+                Err(e) => error!("Error while receiving OnNavigationStarting message: {e}"),
+            }),
+        );
+        Ok(())
     }
 }

verso/src/main.rs

@@ -6,6 +6,12 @@ fn main() {
         versoview_path,
         url::Url::parse("https://example.com").unwrap(),
     );
+    controller
+        .on_navigation_starting(|url| {
+            dbg!(url);
+            true
+        })
+        .unwrap();
     sleep(Duration::from_secs(10));
     dbg!(controller
         .navigate(url::Url::parse("https://docs.rs").unwrap())

versoview_messages/src/lib.rs

@@ -1,7 +1,11 @@
+use ipc_channel::ipc;
 use serde::{Deserialize, Serialize};
 
+pub type OnNavigationStartingPayload = ipc::IpcSender<(url::Url, ipc::IpcSender<bool>)>;
+
 #[derive(Debug, Serialize, Deserialize)]
 #[non_exhaustive]
 pub enum ControllerMessage {
     NavigateTo(url::Url),
+    OnNavigationStarting(OnNavigationStartingPayload),
 }