Unify font classes + By-value-contexts ⚖

1 files changed, 32 insertions, 12 deletions

diff --git a/src/style.rs b/src/style.rs
index cd0a9579..042042bf 100644
--- a/src/style.rs
+++ b/src/style.rs
@@ -1,18 +1,17 @@
 //! Styles for layouting.
 
-use crate::font::FontFamily;
+use crate::font::FontClass;
 use crate::size::{Size, Size2D, SizeBox};
 
 
 /// Default styles for text.
 #[derive(Debug, Clone)]
 pub struct TextStyle {
-    /// A fallback list of font families to use.
-    pub font_families: Vec<FontFamily>,
-    /// Whether the font is in italics.
-    pub italic: bool,
-    /// Whether the font is bold.
-    pub bold: bool,
+    /// The classes the font we want has to be part of.
+    pub classes: Vec<FontClass>,
+    /// A sequence of classes. We need the font to be part of at least one of these
+    /// and preferably the leftmost possible.
+    pub fallback: Vec<FontClass>,
     /// The font size.
     pub font_size: f32,
     /// The line spacing (as a multiple of the font size).
@@ -21,14 +20,35 @@ pub struct TextStyle {
     pub paragraph_spacing: f32,
 }
 
+impl TextStyle {
+    /// Toggle a class.
+    ///
+    /// If the class was one of _italic_ or _bold_, then:
+    /// - If it was not present, the _regular_ class will be removed.
+    /// - If it was present, the _regular_ class will be added in case the
+    ///   other style class is not present.
+    pub fn toggle_class(&mut self, class: FontClass) {
+        if self.classes.contains(&class) {
+            self.classes.retain(|x| x != &class);
+            if (class == FontClass::Italic && !self.classes.contains(&FontClass::Bold))
+               || (class == FontClass::Bold && !self.classes.contains(&FontClass::Italic)) {
+                self.classes.push(FontClass::Regular);
+            }
+        } else {
+            if class == FontClass::Italic || class == FontClass::Bold {
+                self.classes.retain(|x| x != &FontClass::Regular);
+            }
+            self.classes.push(class);
+        }
+    }
+}
+
 impl Default for TextStyle {
     fn default() -> TextStyle {
-        use FontFamily::*;
+        use FontClass::*;
         TextStyle {
-            // Default font family, font size and line spacing.
-            font_families: vec![Serif, SansSerif, Monospace],
-            italic: false,
-            bold: false,
+            classes: vec![Regular],
+            fallback: vec![Serif],
             font_size: 11.0,
             line_spacing: 1.2,
             paragraph_spacing: 1.5,