From 3ec19ae4b6de72a7725668e281b1130d09654959 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Tue, 27 Oct 2020 21:17:50 +0100
Subject: [PATCH] LibGUI+LibGfx+WindowServer: Auto-generate disabled action
 icons :^)

This patch adds a simple filter that makes button and menu item icons
have that "'90s disabled" look when disabled. It's pretty awesome.
---
 Libraries/LibGUI/Button.cpp        |  2 +-
 Libraries/LibGfx/Painter.cpp       | 16 ++++++++++++++++
 Libraries/LibGfx/Painter.h         |  1 +
 Services/Taskbar/TaskbarButton.cpp |  2 +-
 Services/WindowServer/Menu.cpp     |  5 ++++-
 5 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/Libraries/LibGUI/Button.cpp b/Libraries/LibGUI/Button.cpp
index 93539907b5..ea57a27c62 100644
--- a/Libraries/LibGUI/Button.cpp
+++ b/Libraries/LibGUI/Button.cpp
@@ -78,7 +78,7 @@ void Button::paint_event(PaintEvent& event)
             else
                 painter.blit(icon_location, *m_icon, m_icon->rect());
         } else {
-            painter.blit_dimmed(icon_location, *m_icon, m_icon->rect());
+            painter.blit_disabled(icon_location, *m_icon, m_icon->rect(), palette());
         }
     }
     auto& font = is_checked() ? Gfx::Font::default_bold_font() : this->font();
diff --git a/Libraries/LibGfx/Painter.cpp b/Libraries/LibGfx/Painter.cpp
index 38655da1ec..63015774ad 100644
--- a/Libraries/LibGfx/Painter.cpp
+++ b/Libraries/LibGfx/Painter.cpp
@@ -37,6 +37,7 @@
 #include <AK/Utf32View.h>
 #include <AK/Utf8View.h>
 #include <LibGfx/CharacterBitmap.h>
+#include <LibGfx/Palette.h>
 #include <LibGfx/Path.h>
 #include <math.h>
 #include <stdio.h>
@@ -1612,4 +1613,19 @@ void Painter::fill_path(Path& path, Color color, WindingRule winding_rule)
 #endif
 }
 
+void Painter::blit_disabled(const IntPoint& location, const Gfx::Bitmap& bitmap, const IntRect& rect, const Palette& palette)
+{
+    auto bright_color = palette.threed_highlight();
+    auto dark_color = palette.threed_shadow1();
+    blit_filtered(location.translated(1, 1), bitmap, rect, [&](auto) {
+        return bright_color;
+    });
+    blit_filtered(location, bitmap, rect, [&](Color src) {
+        int gray = src.to_grayscale().red();
+        if (gray > 160)
+            return bright_color;
+        return dark_color;
+    });
+}
+
 }
diff --git a/Libraries/LibGfx/Painter.h b/Libraries/LibGfx/Painter.h
index d2b71cb74a..8ae33fc207 100644
--- a/Libraries/LibGfx/Painter.h
+++ b/Libraries/LibGfx/Painter.h
@@ -76,6 +76,7 @@ public:
     void draw_tiled_bitmap(const IntRect& dst_rect, const Gfx::Bitmap&);
     void blit_offset(const IntPoint&, const Gfx::Bitmap&, const IntRect& src_rect, const IntPoint&);
     void blit_scaled(const IntRect&, const Gfx::Bitmap&, const IntRect&, float, float);
+    void blit_disabled(const IntPoint&, const Gfx::Bitmap&, const IntRect&, const Palette&);
     void draw_text(const IntRect&, const StringView&, const Font&, TextAlignment = TextAlignment::TopLeft, Color = Color::Black, TextElision = TextElision::None);
     void draw_text(const IntRect&, const StringView&, TextAlignment = TextAlignment::TopLeft, Color = Color::Black, TextElision = TextElision::None);
     void draw_text(const IntRect&, const Utf32View&, const Font&, TextAlignment = TextAlignment::TopLeft, Color = Color::Black, TextElision = TextElision::None);
diff --git a/Services/Taskbar/TaskbarButton.cpp b/Services/Taskbar/TaskbarButton.cpp
index b1501ed6c7..d1ad0c61b2 100644
--- a/Services/Taskbar/TaskbarButton.cpp
+++ b/Services/Taskbar/TaskbarButton.cpp
@@ -153,7 +153,7 @@ void TaskbarButton::paint_event(GUI::PaintEvent& event)
         else
             painter.blit(icon_location, icon, icon.rect());
     } else {
-        painter.blit_dimmed(icon_location, icon, icon.rect());
+        painter.blit_disabled(icon_location, icon, icon.rect(), palette());
     }
 
     if (!has_progress)
diff --git a/Services/WindowServer/Menu.cpp b/Services/WindowServer/Menu.cpp
index 5f1ae2eb01..1d4120c2d7 100644
--- a/Services/WindowServer/Menu.cpp
+++ b/Services/WindowServer/Menu.cpp
@@ -255,7 +255,10 @@ void Menu::draw()
                     });
                     icon_rect.move_by(-1, -1);
                 }
-                painter.blit(icon_rect.location(), *item.icon(), item.icon()->rect());
+                if (item.is_enabled())
+                    painter.blit(icon_rect.location(), *item.icon(), item.icon()->rect());
+                else
+                    painter.blit_disabled(icon_rect.location(), *item.icon(), item.icon()->rect(), palette);
             }
             auto& previous_font = painter.font();
             if (item.is_default())