feat: Exposing methods required by capturing a hidden webContents (electron#21894)

zeeker999 · web-flow · commit 8e30e21ee657 · 2020-03-23T10:27:15.000-07:00
diff --git a/docs/api/web-contents.md b/docs/api/web-contents.md
@@ -1232,6 +1232,25 @@ Returns `Promise<NativeImage>` - Resolves with a [NativeImage](native-image.md)
 
 Captures a snapshot of the page within `rect`. Omitting `rect` will capture the whole visible page.
 
+#### `contents.isBeingCaptured()`
+
+Returns `Boolean` - Whether this page is being captured. It returns true when the capturer count
+is large then 0.
+
+#### `contents.incrementCapturerCount([size])`
+
+* `size` [Size](structures/size.md) (optional) - The perferred size for the capturer.
+
+Increase the capturer count by one. The page is considered visible when its browser window is
+hidden and the capturer count is non-zero.
+
+This also affects the Page Visibility API.
+
+#### `contents.decrementCapturerCount()`
+
+Decrease the capturer count by one. The page will be set to hidden or occluded state when its
+browser window is hidden or occluded and the capturer count reaches zero.
+
 #### `contents.getPrinters()`
 
 Get the system printer list.
diff --git a/shell/browser/api/atom_api_web_contents.cc b/shell/browser/api/atom_api_web_contents.cc
@@ -2204,6 +2204,23 @@ v8::Local<v8::Promise> WebContents::CapturePage(mate::Arguments* args) {
   return handle;
 }
 
+void WebContents::IncrementCapturerCount(mate::Arguments* args) {
+  gfx::Size size;
+
+  // get size arguments if they exist
+  args->GetNext(&size);
+
+  web_contents()->IncrementCapturerCount(size);
+}
+
+void WebContents::DecrementCapturerCount(mate::Arguments* args) {
+  web_contents()->DecrementCapturerCount();
+}
+
+bool WebContents::IsBeingCaptured() {
+  return web_contents()->IsBeingCaptured();
+}
+
 void WebContents::OnCursorChange(const content::WebCursor& cursor) {
   const content::CursorInfo& info = cursor.info();
 
@@ -2598,6 +2615,9 @@ void WebContents::BuildPrototype(v8::Isolate* isolate,
       .SetMethod("setEmbedder", &WebContents::SetEmbedder)
       .SetMethod("setDevToolsWebContents", &WebContents::SetDevToolsWebContents)
       .SetMethod("getNativeView", &WebContents::GetNativeView)
+      .SetMethod("incrementCapturerCount", &WebContents::IncrementCapturerCount)
+      .SetMethod("decrementCapturerCount", &WebContents::DecrementCapturerCount)
+      .SetMethod("isBeingCaptured", &WebContents::IsBeingCaptured)
       .SetMethod("setWebRTCIPHandlingPolicy",
                  &WebContents::SetWebRTCIPHandlingPolicy)
       .SetMethod("getWebRTCIPHandlingPolicy",
diff --git a/shell/browser/api/atom_api_web_contents.h b/shell/browser/api/atom_api_web_contents.h
@@ -185,6 +185,9 @@ class WebContents : public mate::TrackableObject<WebContents>,
   void SetEmbedder(const WebContents* embedder);
   void SetDevToolsWebContents(const WebContents* devtools);
   v8::Local<v8::Value> GetNativeView() const;
+  void IncrementCapturerCount(mate::Arguments* args);
+  void DecrementCapturerCount(mate::Arguments* args);
+  bool IsBeingCaptured();
 
 #if BUILDFLAG(ENABLE_PRINTING)
   void OnGetDefaultPrinter(base::DictionaryValue print_settings,
