Ladybird+LibWebView: Move most of paint handling to LibWebView

Storing the backup bitmap is the same across Browser and Ladybird. Just
peform that work in LibWebView, and handle only the implementation-
specific nuances within the browsers.

Ladybird/AppKit/UI/LadybirdWebViewBridge.cpp

@@ -112,26 +112,6 @@ void WebViewBridge::notify_server_did_layout(Badge<WebView::WebContentClient>, G
     }
 }
 
-void WebViewBridge::notify_server_did_paint(Badge<WebView::WebContentClient>, i32 bitmap_id, Gfx::IntSize size)
-{
-    if (m_client_state.back_bitmap.id == bitmap_id) {
-        m_client_state.has_usable_bitmap = true;
-        m_client_state.back_bitmap.pending_paints--;
-        m_client_state.back_bitmap.last_painted_size = size;
-        swap(m_client_state.back_bitmap, m_client_state.front_bitmap);
-        // We don't need the backup bitmap anymore, so drop it.
-        m_backup_bitmap = nullptr;
-
-        if (on_ready_to_paint)
-            on_ready_to_paint();
-
-        if (m_client_state.got_repaint_requests_while_painting) {
-            m_client_state.got_repaint_requests_while_painting = false;
-            request_repaint();
-        }
-    }
-}
-
 void WebViewBridge::notify_server_did_invalidate_content_rect(Badge<WebView::WebContentClient>, Gfx::IntRect const&)
 {
     request_repaint();

Ladybird/AppKit/UI/LadybirdWebViewBridge.h

@@ -50,7 +50,6 @@ public:
     Optional<Paintable> paintable();
 
     Function<void(Gfx::IntSize)> on_layout;
-    Function<void()> on_ready_to_paint;
 
     Function<void(Gfx::IntPoint)> on_scroll;
 
@@ -63,7 +62,6 @@ private:
     WebViewBridge(Vector<Gfx::IntRect> screen_rects, float device_pixel_ratio, Optional<StringView> webdriver_content_ipc_path);
 
     virtual void notify_server_did_layout(Badge<WebView::WebContentClient>, Gfx::IntSize content_size) override;
-    virtual void notify_server_did_paint(Badge<WebView::WebContentClient>, i32 bitmap_id, Gfx::IntSize) override;
     virtual void notify_server_did_invalidate_content_rect(Badge<WebView::WebContentClient>, Gfx::IntRect const&) override;
     virtual void notify_server_did_change_selection(Badge<WebView::WebContentClient>) override;
     virtual void notify_server_did_request_cursor_change(Badge<WebView::WebContentClient>, Gfx::StandardCursor cursor) override;

Ladybird/Qt/WebContentView.cpp

@@ -75,6 +75,10 @@ WebContentView::WebContentView(StringView webdriver_content_ipc_path, WebView::E
     });
 
     create_client(enable_callgrind_profiling);
+
+    on_ready_to_paint = [this]() {
+        viewport()->update();
+    };
 }
 
 WebContentView::~WebContentView() = default;
@@ -587,24 +591,6 @@ void WebContentView::create_client(WebView::EnableCallgrindProfiling enable_call
         client().async_connect_to_webdriver(m_webdriver_content_ipc_path);
 }
 
-void WebContentView::notify_server_did_paint(Badge<WebContentClient>, i32 bitmap_id, Gfx::IntSize size)
-{
-    if (m_client_state.back_bitmap.id == bitmap_id) {
-        m_client_state.has_usable_bitmap = true;
-        m_client_state.back_bitmap.pending_paints--;
-        m_client_state.back_bitmap.last_painted_size = size;
-        swap(m_client_state.back_bitmap, m_client_state.front_bitmap);
-        // We don't need the backup bitmap anymore, so drop it.
-        m_backup_bitmap = nullptr;
-        viewport()->update();
-
-        if (m_client_state.got_repaint_requests_while_painting) {
-            m_client_state.got_repaint_requests_while_painting = false;
-            request_repaint();
-        }
-    }
-}
-
 void WebContentView::notify_server_did_invalidate_content_rect(Badge<WebContentClient>, [[maybe_unused]] Gfx::IntRect const& content_rect)
 {
     request_repaint();

Ladybird/Qt/WebContentView.h

@@ -77,7 +77,6 @@ public:
     void update_palette(PaletteMode = PaletteMode::Default);
 
     virtual void notify_server_did_layout(Badge<WebContentClient>, Gfx::IntSize content_size) override;
-    virtual void notify_server_did_paint(Badge<WebContentClient>, i32 bitmap_id, Gfx::IntSize) override;
     virtual void notify_server_did_invalidate_content_rect(Badge<WebContentClient>, Gfx::IntRect const&) override;
     virtual void notify_server_did_change_selection(Badge<WebContentClient>) override;
     virtual void notify_server_did_request_cursor_change(Badge<WebContentClient>, Gfx::StandardCursor cursor) override;

Userland/Libraries/LibWebView/OutOfProcessWebView.cpp

@@ -29,6 +29,10 @@ OutOfProcessWebView::OutOfProcessWebView()
 
     create_client();
 
+    on_ready_to_paint = [this]() {
+        update();
+    };
+
     on_request_file = [this](auto const& path, auto request_id) {
         auto file = FileSystemAccessClient::Client::the().request_file_read_only_approved(window(), path);
 
@@ -175,24 +179,6 @@ void OutOfProcessWebView::screen_rects_change_event(GUI::ScreenRectsChangeEvent&
     client().async_update_screen_rects(event.rects(), event.main_screen_index());
 }
 
-void OutOfProcessWebView::notify_server_did_paint(Badge<WebContentClient>, i32 bitmap_id, Gfx::IntSize size)
-{
-    if (m_client_state.back_bitmap.id == bitmap_id) {
-        m_client_state.has_usable_bitmap = true;
-        m_client_state.back_bitmap.pending_paints--;
-        m_client_state.back_bitmap.last_painted_size = size;
-        swap(m_client_state.back_bitmap, m_client_state.front_bitmap);
-        // We don't need the backup bitmap anymore, so drop it.
-        m_backup_bitmap = nullptr;
-        update();
-
-        if (m_client_state.got_repaint_requests_while_painting) {
-            m_client_state.got_repaint_requests_while_painting = false;
-            request_repaint();
-        }
-    }
-}
-
 void OutOfProcessWebView::notify_server_did_invalidate_content_rect(Badge<WebContentClient>, [[maybe_unused]] Gfx::IntRect const& content_rect)
 {
     request_repaint();

Userland/Libraries/LibWebView/OutOfProcessWebView.h

@@ -83,7 +83,6 @@ private:
     virtual void create_client(EnableCallgrindProfiling = EnableCallgrindProfiling::No) override;
     virtual void update_zoom() override;
     virtual void notify_server_did_layout(Badge<WebContentClient>, Gfx::IntSize content_size) override;
-    virtual void notify_server_did_paint(Badge<WebContentClient>, i32 bitmap_id, Gfx::IntSize) override;
     virtual void notify_server_did_invalidate_content_rect(Badge<WebContentClient>, Gfx::IntRect const&) override;
     virtual void notify_server_did_change_selection(Badge<WebContentClient>) override;
     virtual void notify_server_did_request_cursor_change(Badge<WebContentClient>, Gfx::StandardCursor cursor) override;

Userland/Libraries/LibWebView/ViewImplementation.cpp

@@ -48,6 +48,28 @@ WebContentClient const& ViewImplementation::client() const
     return *m_client_state.client;
 }
 
+void ViewImplementation::server_did_paint(Badge<WebContentClient>, i32 bitmap_id, Gfx::IntSize size)
+{
+    if (m_client_state.back_bitmap.id != bitmap_id)
+        return;
+
+    m_client_state.has_usable_bitmap = true;
+    m_client_state.back_bitmap.pending_paints--;
+    m_client_state.back_bitmap.last_painted_size = size;
+    swap(m_client_state.back_bitmap, m_client_state.front_bitmap);
+
+    // We don't need the backup bitmap anymore, so drop it.
+    m_backup_bitmap = nullptr;
+
+    if (on_ready_to_paint)
+        on_ready_to_paint();
+
+    if (m_client_state.got_repaint_requests_while_painting) {
+        m_client_state.got_repaint_requests_while_painting = false;
+        request_repaint();
+    }
+}
+
 void ViewImplementation::load(AK::URL const& url)
 {
     m_url = url;

Userland/Libraries/LibWebView/ViewImplementation.h

@@ -47,6 +47,8 @@ public:
 
     String const& handle() const { return m_client_state.client_handle; }
 
+    void server_did_paint(Badge<WebContentClient>, i32 bitmap_id, Gfx::IntSize size);
+
     void load(AK::URL const&);
     void load_html(StringView, AK::URL const&);
     void load_empty_document();
@@ -90,6 +92,7 @@ public:
     };
     ErrorOr<void> take_screenshot(ScreenshotType);
 
+    Function<void()> on_ready_to_paint;
     Function<String(Web::HTML::ActivateTab)> on_new_tab;
     Function<void()> on_activate_tab;
     Function<void()> on_close;
@@ -135,7 +138,6 @@ public:
     Function<Gfx::IntRect()> on_fullscreen_window;
 
     virtual void notify_server_did_layout(Badge<WebContentClient>, Gfx::IntSize content_size) = 0;
-    virtual void notify_server_did_paint(Badge<WebContentClient>, i32 bitmap_id, Gfx::IntSize) = 0;
     virtual void notify_server_did_invalidate_content_rect(Badge<WebContentClient>, Gfx::IntRect const&) = 0;
     virtual void notify_server_did_change_selection(Badge<WebContentClient>) = 0;
     virtual void notify_server_did_request_cursor_change(Badge<WebContentClient>, Gfx::StandardCursor cursor) = 0;

Userland/Libraries/LibWebView/WebContentClient.cpp

@@ -25,7 +25,7 @@ void WebContentClient::die()
 
 void WebContentClient::did_paint(Gfx::IntRect const& rect, i32 bitmap_id)
 {
-    m_view.notify_server_did_paint({}, bitmap_id, rect.size());
+    m_view.server_did_paint({}, bitmap_id, rect.size());
 }
 
 void WebContentClient::did_start_loading(AK::URL const& url, bool is_redirect)

Userland/Utilities/headless-browser.cpp

@@ -103,7 +103,6 @@ private:
     HeadlessWebContentView() = default;
 
     void notify_server_did_layout(Badge<WebView::WebContentClient>, Gfx::IntSize) override { }
-    void notify_server_did_paint(Badge<WebView::WebContentClient>, i32, Gfx::IntSize) override { }
     void notify_server_did_invalidate_content_rect(Badge<WebView::WebContentClient>, Gfx::IntRect const&) override { }
     void notify_server_did_change_selection(Badge<WebView::WebContentClient>) override { }
     void notify_server_did_request_cursor_change(Badge<WebView::WebContentClient>, Gfx::StandardCursor) override { }