ThemeEditor: Allow temporarily overriding the system theme

This patch introduces two new buttons to apply the current theme being
edited to the whole system and to reset to the previously selected
on disk system theme.

3 files changed, 126 insertions, 6 deletions

diff --git a/Userland/Applications/ThemeEditor/MainWidget.cpp b/Userland/Applications/ThemeEditor/MainWidget.cpp
index f62618010e..034e3bc16b 100644
--- a/Userland/Applications/ThemeEditor/MainWidget.cpp
+++ b/Userland/Applications/ThemeEditor/MainWidget.cpp
@@ -1,6 +1,6 @@
 /*
  * Copyright (c) 2020, Andreas Kling <kling@serenityos.org>
- * Copyright (c) 2021, Jakob-Niklas See <git@nwex.de>
+ * Copyright (c) 2021-2022, Jakob-Niklas See <git@nwex.de>
  * Copyright (c) 2021-2022, Sam Atkins <atkinssj@serenityos.org>
  * Copyright (c) 2021, Antonio Di Stefano <tonio9681@gmail.com>
  * Copyright (c) 2022, Filiph Sandström <filiph.sandstrom@filfatstudios.com>
@@ -15,6 +15,10 @@
 #include <Applications/ThemeEditor/MetricPropertyGML.h>
 #include <Applications/ThemeEditor/PathPropertyGML.h>
 #include <Applications/ThemeEditor/ThemeEditorGML.h>
+// FIXME: LibIPC Decoder and Encoder are sensitive to include order here
+// clang-format off
+#include <LibGUI/ConnectionToWindowServer.h>
+// clang-format on
 #include <LibFileSystemAccessClient/Client.h>
 #include <LibGUI/ActionGroup.h>
 #include <LibGUI/Application.h>
@@ -196,6 +200,8 @@ MainWidget::MainWidget()
     add_property_tab(window_tab);
     add_property_tab(widgets_tab);
     add_property_tab(syntax_highlighting_tab);
+
+    build_override_controls();
 }
 
 ErrorOr<void> MainWidget::initialize_menubar(GUI::Window& window)
@@ -367,6 +373,84 @@ void MainWidget::save_to_file(Core::File& file)
     }
 }
 
+ErrorOr<Core::AnonymousBuffer> MainWidget::encode()
+{
+    auto buffer = TRY(Core::AnonymousBuffer::create_with_size(sizeof(Gfx::SystemTheme)));
+    auto* data = buffer.data<Gfx::SystemTheme>();
+
+#define __ENUMERATE_ALIGNMENT_ROLE(role) \
+    data->alignment[(int)Gfx::AlignmentRole::role] = m_current_palette.alignment(Gfx::AlignmentRole::role);
+    ENUMERATE_ALIGNMENT_ROLES(__ENUMERATE_ALIGNMENT_ROLE)
+#undef __ENUMERATE_ALIGNMENT_ROLE
+
+#define __ENUMERATE_COLOR_ROLE(role) \
+    data->color[(int)Gfx::ColorRole::role] = m_current_palette.color(Gfx::ColorRole::role).value();
+    ENUMERATE_COLOR_ROLES(__ENUMERATE_COLOR_ROLE)
+#undef __ENUMERATE_COLOR_ROLE
+
+#define __ENUMERATE_FLAG_ROLE(role) \
+    data->flag[(int)Gfx::FlagRole::role] = m_current_palette.flag(Gfx::FlagRole::role);
+    ENUMERATE_FLAG_ROLES(__ENUMERATE_FLAG_ROLE)
+#undef __ENUMERATE_FLAG_ROLE
+
+#define __ENUMERATE_METRIC_ROLE(role) \
+    data->metric[(int)Gfx::MetricRole::role] = m_current_palette.metric(Gfx::MetricRole::role);
+    ENUMERATE_METRIC_ROLES(__ENUMERATE_METRIC_ROLE)
+#undef __ENUMERATE_METRIC_ROLE
+
+#define ENCODE_PATH(role, allow_empty)                                                                                                       \
+    do {                                                                                                                                     \
+        auto path = m_current_palette.path(Gfx::PathRole::role);                                                                             \
+        char const* characters;                                                                                                              \
+        if (path.is_empty()) {                                                                                                               \
+            switch (Gfx::PathRole::role) {                                                                                                   \
+            case Gfx::PathRole::TitleButtonIcons:                                                                                            \
+                characters = "/res/icons/16x16/";                                                                                            \
+                break;                                                                                                                       \
+            default:                                                                                                                         \
+                characters = allow_empty ? "" : "/res/";                                                                                     \
+            }                                                                                                                                \
+        }                                                                                                                                    \
+        characters = path.characters();                                                                                                      \
+        memcpy(data->path[(int)Gfx::PathRole::role], characters, min(strlen(characters) + 1, sizeof(data->path[(int)Gfx::PathRole::role]))); \
+        data->path[(int)Gfx::PathRole::role][sizeof(data->path[(int)Gfx::PathRole::role]) - 1] = '\0';                                       \
+    } while (0)
+
+    ENCODE_PATH(TitleButtonIcons, false);
+    ENCODE_PATH(ActiveWindowShadow, true);
+    ENCODE_PATH(InactiveWindowShadow, true);
+    ENCODE_PATH(TaskbarShadow, true);
+    ENCODE_PATH(MenuShadow, true);
+    ENCODE_PATH(TooltipShadow, true);
+
+    return buffer;
+}
+
+void MainWidget::build_override_controls()
+{
+    auto* theme_override_controls = find_descendant_of_type_named<GUI::Widget>("theme_override_controls");
+
+    m_theme_override_apply = theme_override_controls->find_child_of_type_named<GUI::Button>("apply");
+    m_theme_override_reset = theme_override_controls->find_child_of_type_named<GUI::Button>("reset");
+
+    m_theme_override_apply->on_click = [&](auto) {
+        auto encoded = encode();
+        if (encoded.is_error())
+            return;
+        GUI::ConnectionToWindowServer::the().async_set_system_theme_override(encoded.value());
+    };
+
+    m_theme_override_reset->on_click = [&](auto) {
+        GUI::ConnectionToWindowServer::the().async_clear_system_theme_override();
+    };
+
+    GUI::Application::the()->on_theme_change = [&]() {
+        auto override_active = GUI::ConnectionToWindowServer::the().is_system_theme_overridden();
+        m_theme_override_apply->set_enabled(!override_active && window()->is_modified());
+        m_theme_override_reset->set_enabled(override_active);
+    };
+}
+
 void MainWidget::add_property_tab(PropertyTab const& property_tab)
 {
     auto& scrollable_container = m_property_tabs->add_tab<GUI::ScrollableContainerWidget>(property_tab.title);
@@ -513,6 +597,7 @@ void MainWidget::set_palette(Gfx::Palette palette)
 {
     m_current_palette = move(palette);
     m_preview_widget->set_preview_palette(m_current_palette);
+    m_theme_override_apply->set_enabled(true);
     window()->set_modified(true);
 }
 
diff --git a/Userland/Applications/ThemeEditor/MainWidget.h b/Userland/Applications/ThemeEditor/MainWidget.h
index c93ae3d490..a54a36578d 100644
--- a/Userland/Applications/ThemeEditor/MainWidget.h
+++ b/Userland/Applications/ThemeEditor/MainWidget.h
@@ -91,8 +91,11 @@ private:
     MainWidget();
 
     void save_to_file(Core::File&);
+    ErrorOr<Core::AnonymousBuffer> encode();
     void set_path(String);
 
+    void build_override_controls();
+
     void add_property_tab(PropertyTab const&);
     void set_alignment(Gfx::AlignmentRole, Gfx::TextAlignment);
     void set_color(Gfx::ColorRole, Gfx::Color);
@@ -112,6 +115,9 @@ private:
     RefPtr<GUI::TabWidget> m_property_tabs;
     RefPtr<GUI::Action> m_save_action;
 
+    RefPtr<GUI::Button> m_theme_override_apply;
+    RefPtr<GUI::Button> m_theme_override_reset;
+
     Optional<String> m_path;
     Gfx::Palette m_current_palette;
     Time m_last_modified_time { Time::now_monotonic() };
diff --git a/Userland/Applications/ThemeEditor/ThemeEditor.gml b/Userland/Applications/ThemeEditor/ThemeEditor.gml
index 36d6f48bab..01fec60bad 100644
--- a/Userland/Applications/ThemeEditor/ThemeEditor.gml
+++ b/Userland/Applications/ThemeEditor/ThemeEditor.gml
@@ -1,13 +1,42 @@
 @GUI::Widget {
-    layout: @GUI::HorizontalBoxLayout {}
+    layout: @GUI::VerticalBoxLayout {}
     fill_with_background_color: true
 
-    @GUI::Frame {
+    @GUI::Widget {
         layout: @GUI::HorizontalBoxLayout {}
-        name: "preview_frame"
+
+        @GUI::Frame {
+            layout: @GUI::HorizontalBoxLayout {}
+            name: "preview_frame"
+        }
+
+        @GUI::TabWidget {
+            name: "property_tabs"
+        }
     }
 
-    @GUI::TabWidget {
-        name: "property_tabs"
+    @GUI::Widget {
+        name: "theme_override_controls"
+        layout: @GUI::HorizontalBoxLayout {
+            margins: [ 0, 4 ]
+        }
+
+        fixed_height: 30
+
+        @GUI::Layout::Spacer {}
+
+        @GUI::Button {
+            name: "reset"
+            text: "Reset to Previous System Theme"
+            enabled: false
+            fixed_width: 190
+        }
+
+        @GUI::Button {
+            name: "apply"
+            text: "Apply as System Theme"
+            enabled: false
+            fixed_width: 140
+        }
     }
 }