fix: make popup show when a descendant of an iframe is made fullscreen

Fixes #1015

CHANGELOG.md

@@ -15,6 +15,9 @@ app.
   ([#1003](https://github.com/birchill/10ten-ja-reader/issues/1003)).
 - (Firefox) Fixed occasional flicker on loading Web pages over slow connections
   when the extension is enabled.
+- Made the popup show for sites that make nested contents fullscreen such as
+  Crunchyroll
+  ([#1015](https://github.com/birchill/10ten-ja-reader/issues/1015)).
 - Fixed lookup of Japanese inside `display: contents` containers.
 - Made the copy overlay not show if the user has selected text in the popup.
 - Made shogi shorthand matches not show up when there is a longer word match.

src/content/content.ts

@@ -459,6 +459,17 @@ export class ContentHandler {
   }
 
   isTopMostWindow() {
+    // If a descendant of an iframe is being displayed full-screen, that iframe
+    // can temporarily act as the topmost window.
+    if (document.fullscreenElement) {
+      if (document.fullscreenElement.tagName === 'IFRAME') {
+        return false;
+      }
+      if (document.fullscreenElement.ownerDocument === document) {
+        return true;
+      }
+    }
+
     return (
       this.isEffectiveTopMostWindow || window.self === this.getTopMostWindow()
     );
@@ -1202,6 +1213,16 @@ export class ContentHandler {
     if (this.popupState?.display.mode === 'pinned') {
       this.unpinPopup();
     }
+
+    // If entering / leaving fullscreen caused a change in who is the topmost
+    // window we might have some setup / clean up to do.
+    if (this.isTopMostWindow()) {
+      this.applyPuckConfig();
+    } else {
+      removePopup();
+      this.clearResult();
+      this.tearDownPuck();
+    }
   }
 
   onInterFrameMessage(event: MessageEvent) {