constellation: focusing and closing webviews (#30842)

* constellation: focusing, closing, and native window visibility

* rename “browser” to “webview”, “unfocus” to “blur”

* remove native window visibility from constellation

* rename more “browser” to “webview”

* guard clauses

* don’t automatically focus when no webviews are focused

* comment spec steps for window.close()

* use format interpolation

Co-authored-by: Martin Robinson <mrobinson@igalia.com>

* fix formatting

* rename “Webview” to “WebView” in types and type parameters

* remove unused method

* fix libsimpleservo

---------

Co-authored-by: Martin Robinson <mrobinson@igalia.com>

1 files changed, 46 insertions, 36 deletions

diff --git a/ports/libsimpleservo/api/src/lib.rs b/ports/libsimpleservo/api/src/lib.rs
index 5a3d1e4cd74..069e5745ae5 100644
--- a/ports/libsimpleservo/api/src/lib.rs
+++ b/ports/libsimpleservo/api/src/lib.rs
@@ -31,7 +31,7 @@ use servo::embedder_traits::{
 use servo::euclid::{Point2D, Rect, Scale, Size2D, Vector2D};
 use servo::keyboard_types::{Key, KeyState, KeyboardEvent};
 pub use servo::msg::constellation_msg::InputMethodType;
-use servo::msg::constellation_msg::TraversalDirection;
+use servo::msg::constellation_msg::{TraversalDirection, WebViewId};
 pub use servo::script_traits::{MediaSessionActionType, MouseButton};
 use servo::script_traits::{TouchEventType, TouchId};
 use servo::servo_config::{opts, pref};
@@ -168,19 +168,25 @@ pub struct ServoGlue {
     servo: Servo<ServoWindowCallbacks>,
     batch_mode: bool,
     callbacks: Rc<ServoWindowCallbacks>,
-    /// id of the top level browsing context. It is unique as tabs
-    /// are not supported yet. None until created.
-    browser_id: Option<BrowserId>,
-    // A rudimentary stack of "tabs".
-    // EmbedderMsg::BrowserCreated will push onto it.
-    // EmbedderMsg::CloseBrowser will pop from it,
-    // and exit if it is empty afterwards.
-    browsers: Vec<BrowserId>,
     events: Vec<EmbedderEvent>,
-
     context_menu_sender: Option<IpcSender<ContextMenuResult>>,
+
+    /// List of top-level browsing contexts.
+    /// Modified by EmbedderMsg::WebViewOpened and EmbedderMsg::WebViewClosed,
+    /// and we exit if it ever becomes empty.
+    webviews: HashMap<WebViewId, WebView>,
+
+    /// The order in which the webviews were created.
+    creation_order: Vec<WebViewId>,
+
+    /// The webview that is currently focused.
+    /// Modified by EmbedderMsg::WebViewFocused and EmbedderMsg::WebViewBlurred.
+    focused_webview_id: Option<WebViewId>,
 }
 
+#[derive(Debug)]
+pub struct WebView {}
+
 pub fn servo_version() -> String {
     format!(
         "Servo {}-{}",
@@ -312,12 +318,13 @@ pub fn init(
             servo: servo.servo,
             batch_mode: false,
             callbacks: window_callbacks,
-            browser_id: None,
-            browsers: vec![],
             events: vec![],
             context_menu_sender: None,
+            webviews: HashMap::default(),
+            creation_order: vec![],
+            focused_webview_id: None,
         };
-        let _ = servo_glue.process_event(EmbedderEvent::NewBrowser(url, servo.browser_id));
+        let _ = servo_glue.process_event(EmbedderEvent::NewWebView(url, servo.browser_id));
         *s.borrow_mut() = Some(servo_glue);
     });
 
@@ -330,11 +337,11 @@ pub fn deinit() {
 
 impl ServoGlue {
     fn get_browser_id(&self) -> Result<BrowserId, &'static str> {
-        let browser_id = match self.browser_id {
+        let webview_id = match self.focused_webview_id {
             Some(id) => id,
-            None => return Err("No BrowserId set yet."),
+            None => return Err("No focused WebViewId yet."),
         };
-        Ok(browser_id)
+        Ok(webview_id)
     }
 
     /// Request shutdown. Will call on_shutdown_complete.
@@ -604,7 +611,7 @@ impl ServoGlue {
     pub fn change_visibility(&mut self, visible: bool) -> Result<(), &'static str> {
         info!("change_visibility");
         if let Ok(id) = self.get_browser_id() {
-            let event = EmbedderEvent::ChangeBrowserVisibility(id, visible);
+            let event = EmbedderEvent::WebViewVisibilityChanged(id, visible);
             self.process_event(event)
         } else {
             // Ignore visibility change if no browser has been created yet.
@@ -714,21 +721,35 @@ impl ServoGlue {
                             .push(EmbedderEvent::SendError(browser_id, reason));
                     }
                 },
-                EmbedderMsg::AllowOpeningBrowser(response_chan) => {
+                EmbedderMsg::AllowOpeningWebView(response_chan) => {
                     // Note: would be a place to handle pop-ups config.
                     // see Step 7 of #the-rules-for-choosing-a-browsing-context-given-a-browsing-context-name
                     if let Err(e) = response_chan.send(true) {
                         warn!("Failed to send AllowOpeningBrowser response: {}", e);
                     };
                 },
-                EmbedderMsg::BrowserCreated(new_browser_id) => {
-                    // TODO: properly handle a new "tab"
-                    self.browsers.push(new_browser_id);
-                    if self.browser_id.is_none() {
-                        self.browser_id = Some(new_browser_id);
-                    }
+                EmbedderMsg::WebViewOpened(new_webview_id) => {
+                    self.webviews.insert(new_webview_id, WebView {});
+                    self.creation_order.push(new_webview_id);
                     self.events
-                        .push(EmbedderEvent::SelectBrowser(new_browser_id));
+                        .push(EmbedderEvent::FocusWebView(new_webview_id));
+                },
+                EmbedderMsg::WebViewClosed(webview_id) => {
+                    self.webviews.retain(|&id, _| id != webview_id);
+                    self.creation_order.retain(|&id| id != webview_id);
+                    self.focused_webview_id = None;
+                    if let Some(&newest_webview_id) = self.creation_order.last() {
+                        self.events
+                            .push(EmbedderEvent::FocusWebView(newest_webview_id));
+                    } else {
+                        self.events.push(EmbedderEvent::Quit);
+                    }
+                },
+                EmbedderMsg::WebViewFocused(webview_id) => {
+                    self.focused_webview_id = Some(webview_id);
+                },
+                EmbedderMsg::WebViewBlurred => {
+                    self.focused_webview_id = None;
                 },
                 EmbedderMsg::GetClipboardContents(sender) => {
                     let contents = self.callbacks.host_callbacks.get_clipboard_contents();
@@ -737,17 +758,6 @@ impl ServoGlue {
                 EmbedderMsg::SetClipboardContents(text) => {
                     self.callbacks.host_callbacks.set_clipboard_contents(text);
                 },
-                EmbedderMsg::CloseBrowser => {
-                    // TODO: close the appropriate "tab".
-                    let _ = self.browsers.pop();
-                    if let Some(prev_browser_id) = self.browsers.last() {
-                        self.browser_id = Some(*prev_browser_id);
-                        self.events
-                            .push(EmbedderEvent::SelectBrowser(*prev_browser_id));
-                    } else {
-                        self.events.push(EmbedderEvent::Quit);
-                    }
-                },
                 EmbedderMsg::Shutdown => {
                     self.callbacks.host_callbacks.on_shutdown_complete();
                 },