Use WidgetText for Window title

egui/src/containers/window.rs

@@ -1,6 +1,6 @@
 // WARNING: the code in here is horrible. It is a behemoth that needs breaking up into simpler parts.
 
-use crate::{widgets::*, *};
+use crate::{widget_text::WidgetTextGalley, *};
 use epaint::*;
 
 use super::*;
@@ -23,7 +23,7 @@ use super::*;
 /// });
 #[must_use = "You should call .show()"]
 pub struct Window<'open> {
-    title_label: Label,
+    title: WidgetText,
     open: Option<&'open mut bool>,
     area: Area,
     frame: Option<Frame>,
@@ -37,13 +37,14 @@ impl<'open> Window<'open> {
     /// The window title is used as a unique [`Id`] and must be unique, and should not change.
     /// This is true even if you disable the title bar with `.title_bar(false)`.
     /// If you need a changing title, you must call `window.id(…)` with a fixed id.
-    #[allow(clippy::needless_pass_by_value)]
-    pub fn new(title: impl ToString) -> Self {
-        let title = title.to_string();
-        let area = Area::new(&title);
-        let title_label = Label::new(title).text_style(TextStyle::Heading).wrap(false);
+    pub fn new(title: impl Into<WidgetText>) -> Self {
+        let title = title
+            .into()
+            .fallback_text_style(TextStyle::Heading)
+            .wrap(false);
+        let area = Area::new(title.text());
         Self {
-            title_label,
+            title,
             open: None,
             area,
             frame: None,
@@ -250,7 +251,7 @@ impl<'open> Window<'open> {
         add_contents: Box<dyn FnOnce(&mut Ui) -> R + 'c>,
     ) -> Option<InnerResponse<Option<R>>> {
         let Window {
-            title_label,
+            title,
             open,
             area,
             frame,
@@ -299,7 +300,7 @@ impl<'open> Window<'open> {
             .and_then(|window_interaction| {
                 // Calculate roughly how much larger the window size is compared to the inner rect
                 let title_bar_height = if with_title_bar {
-                    title_label.font_height(ctx.fonts(), &ctx.style()) + title_content_spacing
+                    title.font_height(ctx.fonts(), &ctx.style()) + title_content_spacing
                 } else {
                     0.0
                 };
@@ -336,7 +337,7 @@ impl<'open> Window<'open> {
             let title_bar = if with_title_bar {
                 let title_bar = show_title_bar(
                     &mut frame.content_ui,
-                    title_label,
+                    title,
                     show_close_button,
                     collapsing_id,
                     &mut collapsing,
@@ -745,22 +746,21 @@ fn paint_frame_interaction(
 
 struct TitleBar {
     id: Id,
-    title_label: Label,
-    title_galley: std::sync::Arc<Galley>,
+    title_galley: WidgetTextGalley,
     min_rect: Rect,
     rect: Rect,
 }
 
 fn show_title_bar(
     ui: &mut Ui,
-    title_label: Label,
+    title: WidgetText,
     show_close_button: bool,
     collapsing_id: Id,
     collapsing: &mut collapsing_header::State,
     collapsible: bool,
 ) -> TitleBar {
     let inner_response = ui.horizontal(|ui| {
-        let height = title_label
+        let height = title
             .font_height(ui.fonts(), ui.style())
             .max(ui.spacing().interact_size.y);
         ui.set_min_height(height);
@@ -782,7 +782,7 @@ fn show_title_bar(
             collapsing_header::paint_icon(ui, openness, &collapse_button_response);
         }
 
-        let title_galley = title_label.layout(ui);
+        let title_galley = title.layout(ui, f32::INFINITY, TextStyle::Heading);
 
         let minimum_width = if collapsible || show_close_button {
             // If at least one button is shown we make room for both buttons (since title is centered):
@@ -795,7 +795,6 @@ fn show_title_bar(
 
         TitleBar {
             id,
-            title_label,
             title_galley,
             min_rect,
             rect: Rect::NAN, // Will be filled in later
@@ -830,20 +829,13 @@ impl TitleBar {
             }
         }
 
-        // Always have inactive style for the window.
-        // It is VERY annoying to e.g. change it when moving the window.
-        let style = ui.visuals().widgets.inactive;
-
-        self.title_label = self.title_label.text_color(style.fg_stroke.color);
-
         let full_top_rect = Rect::from_x_y_ranges(self.rect.x_range(), self.min_rect.y_range());
         let text_pos =
             emath::align::center_size_in_rect(self.title_galley.size(), full_top_rect).left_top();
-        let text_pos = text_pos - self.title_galley.rect.min.to_vec2();
+        let text_pos = text_pos - self.title_galley.galley().rect.min.to_vec2();
         let text_pos = text_pos - 1.5 * Vec2::Y; // HACK: center on x-height of text (looks better)
-        let text_color = ui.visuals().text_color();
-        self.title_label
-            .paint_galley(ui, text_pos, self.title_galley, false, text_color);
+        self.title_galley
+            .paint_with_color(ui, text_pos, ui.visuals().text_color());
 
         if let Some(content_response) = &content_response {
             // paint separator between title and content:

egui/src/widget_text.rs

@@ -35,6 +35,13 @@ impl RichText {
         self
     }
 
+    /// Set the [`TextStyle`] unless it has already been set
+    #[inline]
+    pub fn fallback_text_style(mut self, text_style: TextStyle) -> Self {
+        self.text_style.get_or_insert(text_style);
+        self
+    }
+
     /// Use [`TextStyle::Heading`].
     #[inline]
     pub fn heading(self) -> Self {
@@ -67,12 +74,20 @@ impl RichText {
         self
     }
 
+    pub fn font_height(&self, fonts: &epaint::text::Fonts, style: &crate::Style) -> f32 {
+        let text_style = self
+            .text_style
+            .or(style.override_text_style)
+            .unwrap_or(style.body_text_style);
+        fonts.row_height(text_style)
+    }
+
     pub fn layout(
         self,
         ui: &Ui,
         wrap_width: f32,
         default_text_style: TextStyle,
-    ) -> WidgetTextLayout {
+    ) -> WidgetTextGalley {
         let Self {
             text,
             text_style,
@@ -92,7 +107,7 @@ impl RichText {
         if let Some(text_color) = text_color {
             let galley = ui.fonts().layout(text, text_style, text_color, wrap_width);
 
-            WidgetTextLayout {
+            WidgetTextGalley {
                 galley,
                 galley_has_color: true,
             }
@@ -101,7 +116,7 @@ impl RichText {
                 .fonts()
                 .layout_delayed_color(text, text_style, wrap_width);
 
-            WidgetTextLayout {
+            WidgetTextGalley {
                 galley,
                 galley_has_color: false,
             }
@@ -142,6 +157,15 @@ impl WidgetText {
         }
     }
 
+    /// Set the [`TextStyle`] unless it has already been set
+    #[inline]
+    pub fn fallback_text_style(self, text_style: TextStyle) -> Self {
+        match self {
+            Self::RichText(text) => Self::RichText(text.fallback_text_style(text_style)),
+            Self::LayoutJob(_) | Self::Galley(_) => self,
+        }
+    }
+
     /// Override text color if, and only if, this is a [`RichText`].
     #[inline]
     pub fn color(self, color: impl Into<Color32>) -> Self {
@@ -160,22 +184,36 @@ impl WidgetText {
         }
     }
 
+    pub fn font_height(&self, fonts: &epaint::text::Fonts, style: &crate::Style) -> f32 {
+        match self {
+            Self::RichText(text) => text.font_height(fonts, style),
+            Self::LayoutJob(job) => job.font_height(fonts),
+            Self::Galley(galley) => {
+                if let Some(row) = galley.rows.first() {
+                    row.height()
+                } else {
+                    galley.size().y
+                }
+            }
+        }
+    }
+
     pub fn layout(
         self,
         ui: &Ui,
         wrap_width: f32,
         default_text_style: TextStyle,
-    ) -> WidgetTextLayout {
+    ) -> WidgetTextGalley {
         match self {
             Self::RichText(text) => text.layout(ui, wrap_width, default_text_style),
             Self::LayoutJob(mut job) => {
                 job.wrap_width = wrap_width;
-                WidgetTextLayout {
+                WidgetTextGalley {
                     galley: ui.fonts().layout_job(job),
                     galley_has_color: true,
                 }
             }
-            Self::Galley(galley) => WidgetTextLayout {
+            Self::Galley(galley) => WidgetTextGalley {
                 galley,
                 galley_has_color: true,
             },
@@ -221,12 +259,12 @@ impl From<Arc<Galley>> for WidgetText {
 // ----------------------------------------------------------------------------
 
 /// Text that has been layed out and ready to be painted.
-pub struct WidgetTextLayout {
+pub struct WidgetTextGalley {
     galley: Arc<Galley>,
     galley_has_color: bool,
 }
 
-impl WidgetTextLayout {
+impl WidgetTextGalley {
     /// Size of the layed out text.
     #[inline]
     pub fn size(&self) -> crate::Vec2 {
@@ -239,6 +277,11 @@ impl WidgetTextLayout {
         self.galley.text()
     }
 
+    #[inline]
+    pub fn galley(&self) -> &Arc<Galley> {
+        &self.galley
+    }
+
     pub fn paint(self, ui: &Ui, text_pos: Pos2, visuals: &WidgetVisuals) {
         if self.galley_has_color {
             ui.painter().galley(text_pos, self.galley);
@@ -247,4 +290,9 @@ impl WidgetTextLayout {
                 .galley_with_color(text_pos, self.galley, visuals.text_color());
         }
     }
+
+    pub fn paint_with_color(self, ui: &Ui, text_pos: Pos2, text_color: Color32) {
+        ui.painter()
+            .galley_with_color(text_pos, self.galley, text_color);
+    }
 }

epaint/src/text/text_layout_types.rs

@@ -134,6 +134,15 @@ impl LayoutJob {
             format,
         });
     }
+
+    /// The height of the tallest used font in the job.
+    pub fn font_height(&self, fonts: &crate::Fonts) -> f32 {
+        let mut max_height = 0.0_f32;
+        for section in &self.sections {
+            max_height = max_height.max(fonts.row_height(section.format.style));
+        }
+        max_height
+    }
 }
 
 impl std::hash::Hash for LayoutJob {