LibWeb+LibWebView+WebContent: Support muting an entire page

This adds an IPC for chromes to mute a tab. When muted, we trigger an
internal volume change notification and indicate that the user agent has
overriden the media volume.

Userland/Libraries/LibWeb/HTML/AudioPlayState.h

@@ -6,6 +6,8 @@
 
 #pragma once
 
+#include <AK/Assertions.h>
+
 namespace Web::HTML {
 
 enum class AudioPlayState {
@@ -13,4 +15,21 @@ enum class AudioPlayState {
     Playing,
 };
 
+enum class MuteState {
+    Muted,
+    Unmuted,
+};
+
+constexpr MuteState invert_mute_state(MuteState mute_state)
+{
+    switch (mute_state) {
+    case MuteState::Muted:
+        return MuteState::Unmuted;
+    case MuteState::Unmuted:
+        return MuteState::Muted;
+    }
+
+    VERIFY_NOT_REACHED();
+}
+
 }

Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp

@@ -438,11 +438,18 @@ void HTMLMediaElement::volume_or_muted_attribute_changed()
     on_volume_change();
 }
 
+void HTMLMediaElement::page_mute_state_changed(Badge<Page>)
+{
+    on_volume_change();
+}
+
 // https://html.spec.whatwg.org/multipage/media.html#effective-media-volume
 double HTMLMediaElement::effective_media_volume() const
 {
-    // FIXME 1. If the user has indicated that the user agent is to override the volume of the element, then return the
-    //          volume desired by the user.
+    // 1. If the user has indicated that the user agent is to override the volume of the element, then return the
+    //    volume desired by the user.
+    if (document().page().page_mute_state() == MuteState::Muted)
+        return 0.0;
 
     // 2. If the element's audio output is muted, then return zero.
     if (m_muted)

Userland/Libraries/LibWeb/HTML/HTMLMediaElement.h

@@ -98,6 +98,8 @@ public:
     bool muted() const { return m_muted; }
     void set_muted(bool);
 
+    void page_mute_state_changed(Badge<Page>);
+
     double effective_media_volume() const;
 
     JS::NonnullGCPtr<AudioTrackList> audio_tracks() const { return *m_audio_tracks; }

Userland/Libraries/LibWeb/Page/Page.cpp

@@ -470,6 +470,18 @@ WebIDL::ExceptionOr<void> Page::toggle_media_controls_state()
     return {};
 }
 
+void Page::toggle_page_mute_state()
+{
+    m_mute_state = HTML::invert_mute_state(m_mute_state);
+
+    for (auto media_id : m_media_elements) {
+        if (auto* node = DOM::Node::from_unique_id(media_id)) {
+            auto& media_element = verify_cast<HTML::HTMLMediaElement>(*node);
+            media_element.page_mute_state_changed({});
+        }
+    }
+}
+
 JS::GCPtr<HTML::HTMLMediaElement> Page::media_context_menu_element()
 {
     if (!m_media_context_menu_element_id.has_value())

Userland/Libraries/LibWeb/Page/Page.h

@@ -167,6 +167,9 @@ public:
     WebIDL::ExceptionOr<void> toggle_media_loop_state();
     WebIDL::ExceptionOr<void> toggle_media_controls_state();
 
+    HTML::MuteState page_mute_state() const { return m_mute_state; }
+    void toggle_page_mute_state();
+
     Optional<String> const& user_style() const { return m_user_style_sheet_source; }
     void set_user_style(String source);
 
@@ -210,6 +213,8 @@ private:
     Vector<int> m_media_elements;
     Optional<int> m_media_context_menu_element_id;
 
+    Web::HTML::MuteState m_mute_state { Web::HTML::MuteState::Unmuted };
+
     Optional<String> m_user_style_sheet_source;
 
     // https://html.spec.whatwg.org/multipage/system-state.html#pdf-viewer-supported

Userland/Libraries/LibWebView/ViewImplementation.cpp

@@ -315,6 +315,12 @@ void ViewImplementation::toggle_media_controls_state()
     client().async_toggle_media_controls_state(page_id());
 }
 
+void ViewImplementation::toggle_page_mute_state()
+{
+    m_mute_state = Web::HTML::invert_mute_state(m_mute_state);
+    client().async_toggle_page_mute_state(page_id());
+}
+
 void ViewImplementation::did_change_audio_play_state(Badge<WebContentClient>, Web::HTML::AudioPlayState play_state)
 {
     bool state_changed = false;

Userland/Libraries/LibWebView/ViewImplementation.h

@@ -102,6 +102,9 @@ public:
     void toggle_media_loop_state();
     void toggle_media_controls_state();
 
+    Web::HTML::MuteState page_mute_state() const { return m_mute_state; }
+    void toggle_page_mute_state();
+
     void did_change_audio_play_state(Badge<WebContentClient>, Web::HTML::AudioPlayState);
     Web::HTML::AudioPlayState audio_play_state() const { return m_audio_play_state; }
 
@@ -261,6 +264,8 @@ protected:
 
     Web::HTML::AudioPlayState m_audio_play_state { Web::HTML::AudioPlayState::Paused };
     size_t m_number_of_elements_playing_audio { 0 };
+
+    Web::HTML::MuteState m_mute_state { Web::HTML::MuteState::Unmuted };
 };
 
 }

Userland/Services/WebContent/ConnectionFromClient.cpp

@@ -1072,6 +1072,12 @@ void ConnectionFromClient::toggle_media_controls_state(u64 page_id)
         page->page().toggle_media_controls_state().release_value_but_fixme_should_propagate_errors();
 }
 
+void ConnectionFromClient::toggle_page_mute_state(u64 page_id)
+{
+    if (auto page = this->page(page_id); page.has_value())
+        page->page().toggle_page_mute_state();
+}
+
 void ConnectionFromClient::set_user_style(u64 page_id, String const& source)
 {
     if (auto page = this->page(page_id); page.has_value())

Userland/Services/WebContent/ConnectionFromClient.h

@@ -111,6 +111,8 @@ private:
     virtual void toggle_media_loop_state(u64 page_id) override;
     virtual void toggle_media_controls_state(u64 page_id) override;
 
+    virtual void toggle_page_mute_state(u64 page_id) override;
+
     virtual void set_user_style(u64 page_id, String const&) override;
 
     virtual void enable_inspector_prototype(u64 page_id) override;

Userland/Services/WebContent/WebContentServer.ipc

@@ -98,6 +98,8 @@ endpoint WebContentServer
     toggle_media_loop_state(u64 page_id) =|
     toggle_media_controls_state(u64 page_id) =|
 
+    toggle_page_mute_state(u64 page_id) =|
+
     set_user_style(u64 page_id, String source) =|
 
     enable_inspector_prototype(u64 page_id) =|