Widgets will now always line break at `\n` characters

CHANGELOG.md

@@ -19,11 +19,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 * Add `Slider::clamp_to_range(bool)`: if set, clamp the incoming and outgoing values to the slider range.
 * Add: `ui.spacing()`, `ui.spacing_mut()`, `ui.visuals()`, `ui.visuals_mut()`.
 * Add: `ctx.set_visuals()`.
+* You can now control text wrapping with `Style::wrap`.
 
 ### Changed 🔧
 
 * Text will now wrap at newlines, spaces, dashes, punctuation or in the middle of a words if necessary, in that order of priority.
-* `mouse` has be renamed `pointer` everywhere (to make it clear it includes touches too).
+* Widgets will now always line break at `\n` characters.
+* `mouse` has been renamed `pointer` everywhere (to make it clear it includes touches too).
 * Most parts of `Response` are now methods, so `if ui.button("…").clicked {` is now `if ui.button("…").clicked() {`.
 * `Response::active` is now gone. You can use `response.dragged()` or `response.clicked()` instead.
 * Backend: pointer (mouse/touch) position and buttons are now passed to egui in the event stream.

egui/src/containers/collapsing_header.rs

@@ -134,9 +134,7 @@ pub struct CollapsingHeader {
 impl CollapsingHeader {
     /// The `CollapsingHeader` starts out collapsed unless you call `default_open`.
     pub fn new(label: impl Into<String>) -> Self {
-        let label = Label::new(label)
-            .text_style(TextStyle::Button)
-            .multiline(false);
+        let label = Label::new(label).text_style(TextStyle::Button).wrap(false);
         let id_source = Id::new(label.text());
         Self {
             label,

egui/src/containers/combo_box.rs

@@ -64,7 +64,7 @@ pub fn combo_box(
 
         let text_style = TextStyle::Button;
         let font = &ui.fonts()[text_style];
-        let galley = font.layout_single_line(selected.into());
+        let galley = font.layout_no_wrap(selected.into());
 
         let width = galley.size.x + ui.spacing().item_spacing.x + icon_size.x;
         let width = width.at_least(full_minimum_width);

egui/src/containers/window.rs

@@ -38,9 +38,7 @@ impl<'open> Window<'open> {
     pub fn new(title: impl Into<String>) -> Self {
         let title = title.into();
         let area = Area::new(&title);
-        let title_label = Label::new(title)
-            .text_style(TextStyle::Heading)
-            .multiline(false);
+        let title_label = Label::new(title).text_style(TextStyle::Heading).wrap(false);
         Self {
             title_label,
             open: None,

egui/src/introspection.rs

@@ -116,7 +116,7 @@ impl Widget for &epaint::stats::PaintStats {
 }
 
 pub fn label(ui: &mut Ui, alloc_info: &epaint::stats::AllocInfo, what: &str) -> Response {
-    ui.add(Label::new(alloc_info.format(what)).multiline(false))
+    ui.add(Label::new(alloc_info.format(what)).wrap(false))
 }
 
 impl Widget for &mut epaint::TessellationOptions {

egui/src/style.rs

@@ -17,6 +17,11 @@ pub struct Style {
     /// Default `TextStyle` for normal text (i.e. for `Label` and `TextEdit`).
     pub body_text_style: TextStyle,
 
+    /// If set, labels buttons wtc will use this to determine whether or not
+    /// to wrap the text at the right edge of the `Ui` they are in.
+    /// By default this is `None`.
+    pub wrap: Option<bool>,
+
     pub spacing: Spacing,
     pub interaction: Interaction,
     pub visuals: Visuals,
@@ -263,6 +268,7 @@ impl Default for Style {
     fn default() -> Self {
         Self {
             body_text_style: TextStyle::Body,
+            wrap: None,
             spacing: Spacing::default(),
             interaction: Interaction::default(),
             visuals: Visuals::default(),
@@ -460,6 +466,7 @@ impl Style {
     pub fn ui(&mut self, ui: &mut crate::Ui) {
         let Self {
             body_text_style,
+            wrap: _,
             spacing,
             interaction,
             visuals,

egui/src/ui.rs

@@ -170,6 +170,17 @@ impl Ui {
         self.placer.layout()
     }
 
+    /// Should text wrap in this `Ui`?
+    /// This is determined first by [`Style::wrap`], and then by the layout of this `Ui`.
+    pub fn wrap_text(&self) -> bool {
+        if let Some(wrap) = self.style.wrap {
+            wrap
+        } else {
+            // In vertical layouts we wrap text, but in horizontal we keep going.
+            self.layout().is_vertical()
+        }
+    }
+
     /// Create a painter for a sub-region of this Ui.
     ///
     /// The clip-rect of the returned `Painter` will be the intersection

egui/src/widgets/button.rs

@@ -87,19 +87,19 @@ impl Widget for Button {
             small,
             frame,
         } = self;
-        let font = &ui.fonts()[text_style];
-
-        let single_line = ui.layout().is_horizontal();
-        let galley = if single_line {
-            font.layout_single_line(text)
-        } else {
-            font.layout_multiline(text, ui.available_width())
-        };
 
         let mut button_padding = ui.spacing().button_padding;
         if small {
             button_padding.y = 0.0;
         }
+        let total_extra = button_padding + button_padding;
+
+        let font = &ui.fonts()[text_style];
+        let galley = if ui.wrap_text() {
+            font.layout_multiline(text, ui.available_width() - total_extra.x)
+        } else {
+            font.layout_no_wrap(text)
+        };
 
         let mut desired_size = galley.size + 2.0 * button_padding;
         if !small {
@@ -180,11 +180,10 @@ impl<'a> Widget for Checkbox<'a> {
         let button_padding = spacing.button_padding;
         let total_extra = button_padding + vec2(icon_width + icon_spacing, 0.0) + button_padding;
 
-        let single_line = ui.layout().is_horizontal();
-        let galley = if single_line {
-            font.layout_single_line(text)
-        } else {
+        let galley = if ui.wrap_text() {
             font.layout_multiline(text, ui.available_width() - total_extra.x)
+        } else {
+            font.layout_no_wrap(text)
         };
 
         let mut desired_size = total_extra + galley.size;
@@ -272,11 +271,10 @@ impl Widget for RadioButton {
         let button_padding = ui.spacing().button_padding;
         let total_extra = button_padding + vec2(icon_width + icon_spacing, 0.0) + button_padding;
 
-        let single_line = ui.layout().is_horizontal();
-        let galley = if single_line {
-            font.layout_single_line(text)
-        } else {
+        let galley = if ui.wrap_text() {
             font.layout_multiline(text, ui.available_width() - total_extra.x)
+        } else {
+            font.layout_no_wrap(text)
         };
 
         let mut desired_size = total_extra + galley.size;

egui/src/widgets/label.rs

@@ -5,7 +5,7 @@ use crate::{paint::Galley, *};
 pub struct Label {
     // TODO: not pub
     pub(crate) text: String,
-    pub(crate) multiline: Option<bool>,
+    pub(crate) wrap: Option<bool>,
     pub(crate) text_style: Option<TextStyle>,
     pub(crate) background_color: Color32,
     pub(crate) text_color: Option<Color32>,
@@ -21,7 +21,7 @@ impl Label {
     pub fn new(text: impl Into<String>) -> Self {
         Self {
             text: text.into(),
-            multiline: None,
+            wrap: None,
             text_style: None,
             background_color: Color32::TRANSPARENT,
             text_color: None,
@@ -39,16 +39,21 @@ impl Label {
     }
 
     /// If `true`, the text will wrap at the `max_width`.
-    /// By default `multiline` will be true in vertical layouts
+    /// By default [`wrap`] will be true in vertical layouts
     /// and horizontal layouts with wrapping,
     /// and false on non-wrapping horizontal layouts.
     ///
-    /// If the text has any newlines (`\n`) in it, multiline will automatically turn on.
-    pub fn multiline(mut self, multiline: bool) -> Self {
-        self.multiline = Some(multiline);
+    /// Note that any `\n` in the text label will always produce a new line.
+    pub fn wrap(mut self, wrap: bool) -> Self {
+        self.wrap = Some(wrap);
         self
     }
 
+    #[deprecated = "Use Label::wrap instead"]
+    pub fn multiline(self, multiline: bool) -> Self {
+        self.wrap(multiline)
+    }
+
     /// The default is [`Style::body_text_style`] (generally [`TextStyle::Body`]).
     pub fn text_style(mut self, text_style: TextStyle) -> Self {
         self.text_style = Some(text_style);
@@ -122,11 +127,12 @@ impl Label {
     pub fn layout_width(&self, ui: &Ui, max_width: f32) -> Galley {
         let text_style = self.text_style_or_default(ui.style());
         let font = &ui.fonts()[text_style];
-        if self.is_multiline(ui) {
-            font.layout_multiline(self.text.clone(), max_width) // TODO: avoid clone
+        let wrap_width = if self.should_wrap(ui) {
+            max_width
         } else {
-            font.layout_single_line(self.text.clone()) // TODO: avoid clone
-        }
+            f32::INFINITY
+        };
+        font.layout_multiline(self.text.clone(), wrap_width) // TODO: avoid clone
     }
 
     pub fn font_height(&self, fonts: &paint::text::Fonts, style: &Style) -> f32 {
@@ -207,19 +213,17 @@ impl Label {
         self.text_style.unwrap_or(style.body_text_style)
     }
 
-    fn is_multiline(&self, ui: &Ui) -> bool {
-        self.multiline.unwrap_or_else(|| {
+    fn should_wrap(&self, ui: &Ui) -> bool {
+        self.wrap.or(ui.style().wrap).unwrap_or_else(|| {
             let layout = ui.layout();
-            layout.is_vertical()
-                || layout.is_horizontal() && layout.main_wrap()
-                || self.text.contains('\n')
+            layout.is_vertical() || layout.is_horizontal() && layout.main_wrap()
         })
     }
 }
 
 impl Widget for Label {
     fn ui(self, ui: &mut Ui) -> Response {
-        if self.is_multiline(ui)
+        if self.should_wrap(ui)
             && ui.layout().main_dir() == Direction::LeftToRight
             && ui.layout().main_wrap()
         {

egui/src/widgets/selected_label.rs

@@ -29,11 +29,10 @@ impl Widget for SelectableLabel {
         let button_padding = ui.spacing().button_padding;
         let total_extra = button_padding + button_padding;
 
-        let single_line = ui.layout().is_horizontal();
-        let galley = if single_line {
-            font.layout_single_line(text)
-        } else {
+        let galley = if ui.wrap_text() {
             font.layout_multiline(text, ui.available_width() - total_extra.x)
+        } else {
+            font.layout_no_wrap(text)
         };
 
         let mut desired_size = total_extra + galley.size;

egui/src/widgets/slider.rs

@@ -324,12 +324,7 @@ impl<'a> Slider<'a> {
     fn label_ui(&mut self, ui: &mut Ui) {
         if let Some(label_text) = self.text.as_deref() {
             let text_color = self.text_color.unwrap_or_else(|| ui.visuals().text_color());
-
-            ui.add(
-                Label::new(label_text)
-                    .multiline(false)
-                    .text_color(text_color),
-            );
+            ui.add(Label::new(label_text).wrap(false).text_color(text_color));
         }
     }
 

epaint/src/text/font.rs

@@ -275,6 +275,9 @@ impl Font {
     /// Typeset the given text onto one row.
     /// Any `\n` will show up as the replacement character.
     /// Always returns exactly one `Row` in the `Galley`.
+    ///
+    /// Most often you probably want `\n` to produce a new row,
+    /// and so [`Self::layout_no_wrap`] may be a better choice.
     pub fn layout_single_line(&self, text: String) -> Galley {
         let x_offsets = self.layout_single_row_fragment(&text);
         let row = Row {
@@ -295,6 +298,13 @@ impl Font {
     }
 
     /// Always returns at least one row.
+    /// Will line break at `\n`.
+    pub fn layout_no_wrap(&self, text: String) -> Galley {
+        self.layout_multiline(text, f32::INFINITY)
+    }
+
+    /// Always returns at least one row.
+    /// Will wrap text at the given width.
     pub fn layout_multiline(&self, text: String, max_width_in_points: f32) -> Galley {
         self.layout_multiline_with_indentation_and_max_width(text, 0.0, max_width_in_points)
     }