Add ability to override text color with `visuals.override_text_color`

This is kind of hacky; I may redesign this later

egui/src/containers/combo_box.rs

@@ -94,15 +94,15 @@ fn button_frame(
 
     let mut response = ui.interact(outer_rect, id, sense);
     response.active |= button_active;
-    let style = ui.style().interact(&response);
+    let visuals = ui.style().interact(&response);
 
     ui.painter().set(
         where_to_put_background,
         PaintCmd::Rect {
             rect: outer_rect,
-            corner_radius: style.corner_radius,
-            fill: style.bg_fill,
-            stroke: style.bg_stroke,
+            corner_radius: visuals.corner_radius,
+            fill: visuals.bg_fill,
+            stroke: visuals.bg_stroke,
         },
     );
 

egui/src/style.rs

@@ -99,6 +99,22 @@ pub struct Interaction {
 #[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub struct Visuals {
+    /// Override default text color for all text.
+    ///
+    /// This is great for setting the color of text for any widget.
+    ///
+    /// If `text_color` is `None` (default), then the text color will be the same as the
+    /// foreground stroke color (`WidgetVisuals::fg_stroke`)
+    /// and will depend on wether or not the widget is being interacted with.
+    ///
+    /// In the future we may instead modulate
+    /// the `text_color` based on wether or not it is interacted with
+    /// so that `visuals.text_color` is always used,
+    /// but its alpha may be different based on whether or not
+    /// it is disabled, non-interactive, hovered etc.
+    pub override_text_color: Option<Srgba>,
+
+    /// Visual styles of widgets
     pub widgets: Widgets,
 
     /// e.g. the background of the slider or text edit,
@@ -128,7 +144,8 @@ impl Visuals {
     }
 
     pub fn text_color(&self) -> Srgba {
-        self.widgets.noninteractive.text_color()
+        self.override_text_color
+            .unwrap_or_else(|| self.widgets.noninteractive.text_color())
     }
 }
 
@@ -230,6 +247,7 @@ impl Default for Interaction {
 impl Default for Visuals {
     fn default() -> Self {
         Self {
+            override_text_color: None,
             widgets: Default::default(),
             dark_bg_color: Srgba::black_alpha(140),
             window_corner_radius: 10.0,
@@ -409,6 +427,7 @@ impl Visuals {
         }
 
         let Self {
+            override_text_color: _,
             widgets,
             dark_bg_color,
             window_corner_radius,

egui/src/widgets/mod.rs

@@ -197,7 +197,7 @@ impl Widget for Hyperlink {
             ui.ctx().output().open_url = Some(url.clone());
         }
 
-        let style = ui.style().interact(&response);
+        let visuals = ui.style().interact(&response);
 
         if response.hovered {
             // Underline:
@@ -209,7 +209,7 @@ impl Widget for Hyperlink {
                 let max_x = pos.x + line.max_x();
                 ui.painter().line_segment(
                     [pos2(min_x, y), pos2(max_x, y)],
-                    (style.fg_stroke.width, color),
+                    (visuals.fg_stroke.width, color),
                 );
             }
         }
@@ -301,16 +301,22 @@ impl Widget for Button {
         let rect = ui.allocate_space(desired_size);
 
         let response = ui.interact(rect, id, sense);
-        let style = ui.style().interact(&response);
+        let visuals = ui.style().interact(&response);
         // let text_cursor = response.rect.center() - 0.5 * galley.size; // centered-centered (looks bad for justified drop-down menus
         let text_cursor = pos2(
             response.rect.left() + button_padding.x,
             response.rect.center().y - 0.5 * galley.size.y,
         ); // left-centered
-        let fill = fill.unwrap_or(style.bg_fill);
-        ui.painter()
-            .rect(response.rect, style.corner_radius, fill, style.bg_stroke);
-        let text_color = text_color.unwrap_or_else(|| style.text_color());
+        let fill = fill.unwrap_or(visuals.bg_fill);
+        ui.painter().rect(
+            response.rect,
+            visuals.corner_radius,
+            fill,
+            visuals.bg_stroke,
+        );
+        let text_color = text_color
+            .or(ui.style().visuals.override_text_color)
+            .unwrap_or_else(|| visuals.text_color());
         ui.painter()
             .galley(text_cursor, galley, text_style, text_color);
         response
@@ -397,7 +403,9 @@ impl<'a> Widget for Checkbox<'a> {
             });
         }
 
-        let text_color = text_color.unwrap_or_else(|| visuals.text_color());
+        let text_color = text_color
+            .or(ui.style().visuals.override_text_color)
+            .unwrap_or_else(|| visuals.text_color());
         ui.painter()
             .galley(text_cursor, galley, text_style, text_color);
         response
@@ -481,7 +489,9 @@ impl Widget for RadioButton {
             });
         }
 
-        let text_color = text_color.unwrap_or_else(|| visuals.text_color());
+        let text_color = text_color
+            .or(ui.style().visuals.override_text_color)
+            .unwrap_or_else(|| visuals.text_color());
         painter.galley(text_cursor, galley, text_style, text_color);
         response
     }

egui/src/widgets/text_edit.rs

@@ -216,7 +216,9 @@ impl<'t> Widget for TextEdit<'t> {
             }
         }
 
-        let text_color = text_color.unwrap_or_else(|| visuals.text_color());
+        let text_color = text_color
+            .or(ui.style().visuals.override_text_color)
+            .unwrap_or_else(|| visuals.text_color());
         painter.galley(response.rect.min, galley, text_style, text_color);
         ui.memory().text_edit.insert(id, state);
         response