WindowServer: New title bar vars for themes

The theming system can now control title bar height, title button
size, title stripe color and the title text shadow color.
The implemented theme metrics system could be later extended to LibGUI
to allow themes to change widget padding, border width, etc.

Libraries/LibGfx/Palette.cpp

@@ -61,6 +61,12 @@ Color PaletteImpl::color(ColorRole role) const
     return theme().color[(int)role];
 }
 
+int PaletteImpl::metric(MetricRole role) const
+{
+    ASSERT((int)role < (int)MetricRole::__Count);
+    return theme().metric[(int)role];
+}
+
 NonnullRefPtr<PaletteImpl> PaletteImpl::clone() const
 {
     auto new_theme_buffer = SharedBuffer::create_with_size(m_theme_buffer->size());
@@ -76,6 +82,14 @@ void Palette::set_color(ColorRole role, Color color)
     theme.color[(int)role] = color;
 }
 
+void Palette::set_metric(MetricRole role, int value)
+{
+    if (m_impl->ref_count() != 1)
+        m_impl = m_impl->clone();
+    auto& theme = const_cast<SystemTheme&>(impl().theme());
+    theme.metric[(int)role] = value;
+}
+
 PaletteImpl::~PaletteImpl()
 {
 }

Libraries/LibGfx/Palette.h

@@ -44,6 +44,7 @@ public:
     NonnullRefPtr<PaletteImpl> clone() const;
 
     Color color(ColorRole) const;
+    int metric(MetricRole) const;
     const SystemTheme& theme() const;
 
     void replace_internal_buffer(Badge<GUI::Application>, SharedBuffer& buffer);
@@ -79,6 +80,8 @@ public:
     Color highlight_window_border1() const { return color(ColorRole::HighlightWindowBorder1); }
     Color highlight_window_border2() const { return color(ColorRole::HighlightWindowBorder2); }
     Color highlight_window_title() const { return color(ColorRole::HighlightWindowTitle); }
+    Color window_title_stripes() const { return color(ColorRole::WindowTitleStripes); }
+    Color window_title_shadow() const { return color(ColorRole::WindowTitleShadow); }
     Color menu_stripe() const { return color(ColorRole::MenuStripe); }
     Color menu_base() const { return color(ColorRole::MenuBase); }
     Color menu_base_text() const { return color(ColorRole::MenuBaseText); }
@@ -117,9 +120,15 @@ public:
     Color syntax_preprocessor_statement() const { return color(ColorRole::SyntaxPreprocessorStatement); }
     Color syntax_preprocessor_value() const { return color(ColorRole::SyntaxPreprocessorValue); }
 
+    int window_title_height() const { return metric(MetricRole::TitleHeight); }
+    int window_title_button_width() const { return metric(MetricRole::TitleButtonWidth); }
+    int window_title_button_height() const { return metric(MetricRole::TitleButtonHeight); }
+
     Color color(ColorRole role) const { return m_impl->color(role); }
+    int metric(MetricRole role) const { return m_impl->metric(role); }
 
     void set_color(ColorRole, Color);
+    void set_metric(MetricRole, int);
 
     const SystemTheme& theme() const { return m_impl->theme(); }
 

Libraries/LibGfx/SystemTheme.cpp

@@ -67,6 +67,24 @@ RefPtr<SharedBuffer> load_system_theme(const String& path)
         return color.value();
     };
 
+    auto get_metric = [&](auto& name, auto role) {
+        int metric = file->read_num_entry("Metrics", name, -1);
+        if (metric == -1) {
+            switch (role) {
+            case (int)MetricRole::TitleHeight:
+                return 19;
+            case (int)MetricRole::TitleButtonHeight:
+                return 15;
+            case (int)MetricRole::TitleButtonWidth:
+                return 15;
+            default:
+                dbg() << "Metric " << name << " has no fallback value!";
+                return 16;
+            }
+        }
+        return metric;
+    };
+
 #define DO_COLOR(x) \
     data->color[(int)ColorRole::x] = get_color(#x)
 
@@ -98,6 +116,8 @@ RefPtr<SharedBuffer> load_system_theme(const String& path)
     DO_COLOR(HighlightWindowBorder1);
     DO_COLOR(HighlightWindowBorder2);
     DO_COLOR(HighlightWindowTitle);
+    DO_COLOR(WindowTitleShadow);
+    DO_COLOR(WindowTitleStripes);
     DO_COLOR(MenuStripe);
     DO_COLOR(MenuBase);
     DO_COLOR(MenuBaseText);
@@ -126,6 +146,13 @@ RefPtr<SharedBuffer> load_system_theme(const String& path)
     DO_COLOR(SyntaxPreprocessorStatement);
     DO_COLOR(SyntaxPreprocessorValue);
 
+#define DO_METRIC(x) \
+    data->metric[(int)MetricRole::x] = get_metric(#x, (int)MetricRole::x)
+
+    DO_METRIC(TitleHeight);
+    DO_METRIC(TitleButtonWidth);
+    DO_METRIC(TitleButtonHeight);
+
     buffer->seal();
     buffer->share_globally();
 

Libraries/LibGfx/SystemTheme.h

@@ -47,6 +47,8 @@ enum class ColorRole {
     HighlightWindowBorder1,
     HighlightWindowBorder2,
     HighlightWindowTitle,
+    WindowTitleShadow,
+    WindowTitleStripes,
     MenuStripe,
     MenuBase,
     MenuBaseText,
@@ -95,8 +97,17 @@ enum class ColorRole {
     DisabledText = ThreedShadow1,
 };
 
+enum class MetricRole {
+    NoRole,
+    TitleHeight,
+    TitleButtonWidth,
+    TitleButtonHeight,
+    __Count,
+};
+
 struct SystemTheme {
     Color color[(int)ColorRole::__Count];
+    int metric[(int)MetricRole::__Count];
 };
 
 const SystemTheme& current_system_theme();