From cdf87d22044ccb2b87191d73827bc8f2c6f6a51a Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Tue, 29 Dec 2020 00:44:58 +0100
Subject: [PATCH] LibWeb: Fill OOPWV with the palette base color until we have
 pixels

We were painting unfinished pixels while waiting for the WebContent
process to render the page. This caused OOPWV to flicker black
sometimes, which looked pretty bad.

This way we still flicker, but at least we flicker with the correct
palette color. :^)
---
 Libraries/LibWeb/OutOfProcessWebView.cpp | 11 ++++++++++-
 Libraries/LibWeb/OutOfProcessWebView.h   |  2 ++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/Libraries/LibWeb/OutOfProcessWebView.cpp b/Libraries/LibWeb/OutOfProcessWebView.cpp
index 7044a2c63c..50c71de703 100644
--- a/Libraries/LibWeb/OutOfProcessWebView.cpp
+++ b/Libraries/LibWeb/OutOfProcessWebView.cpp
@@ -31,6 +31,7 @@
 #include <LibGUI/Painter.h>
 #include <LibGUI/ScrollBar.h>
 #include <LibGUI/Window.h>
+#include <LibGfx/Palette.h>
 #include <LibGfx/SystemTheme.h>
 
 REGISTER_WIDGET(Web, OutOfProcessWebView)
@@ -76,8 +77,14 @@ void OutOfProcessWebView::paint_event(GUI::PaintEvent& event)
         return;
 
     GUI::Painter painter(*this);
-    painter.add_clip_rect(frame_inner_rect());
     painter.add_clip_rect(event.rect());
+
+    if (!m_has_usable_bitmap) {
+        painter.fill_rect(frame_inner_rect(), palette().base());
+        return;
+    }
+
+    painter.add_clip_rect(frame_inner_rect());
     painter.translate(frame_thickness(), frame_thickness());
 
     ASSERT(m_front_bitmap);
@@ -92,6 +99,7 @@ void OutOfProcessWebView::resize_event(GUI::ResizeEvent& event)
 
     m_front_bitmap = nullptr;
     m_back_bitmap = nullptr;
+    m_has_usable_bitmap = false;
 
     if (available_size().is_empty())
         return;
@@ -143,6 +151,7 @@ void OutOfProcessWebView::theme_change_event(GUI::ThemeChangeEvent& event)
 void OutOfProcessWebView::notify_server_did_paint(Badge<WebContentClient>, i32 shbuf_id)
 {
     if (m_back_bitmap->shbuf_id() == shbuf_id) {
+        m_has_usable_bitmap = true;
         swap(m_back_bitmap, m_front_bitmap);
         update();
     }
diff --git a/Libraries/LibWeb/OutOfProcessWebView.h b/Libraries/LibWeb/OutOfProcessWebView.h
index 5779d6f6da..a742a01af8 100644
--- a/Libraries/LibWeb/OutOfProcessWebView.h
+++ b/Libraries/LibWeb/OutOfProcessWebView.h
@@ -89,6 +89,8 @@ private:
     RefPtr<WebContentClient> m_client;
     RefPtr<Gfx::Bitmap> m_front_bitmap;
     RefPtr<Gfx::Bitmap> m_back_bitmap;
+
+    bool m_has_usable_bitmap { false };
 };
 
 }