Fix horizontal text alignment

core/src/renderer/null.rs

@@ -87,8 +87,8 @@ impl text::Paragraph for () {
         text::Difference::None
     }
 
-    fn horizontal_alignment(&self) -> alignment::Horizontal {
+    fn horizontal_alignment(&self) -> Option<alignment::Horizontal> {
-        alignment::Horizontal::Left
+        None
     }
 
     fn vertical_alignment(&self) -> alignment::Vertical {

core/src/text.rs

@@ -34,7 +34,7 @@ pub struct Text<Content = String, Font = crate::Font> {
     pub font: Font,
 
     /// The horizontal alignment of the [`Text`].
-    pub horizontal_alignment: alignment::Horizontal,
+    pub horizontal_alignment: Option<alignment::Horizontal>,
 
     /// The vertical alignment of the [`Text`].
     pub vertical_alignment: alignment::Vertical,

core/src/text/paragraph.rs

@@ -24,7 +24,7 @@ pub trait Paragraph: Sized + Default {
     fn compare(&self, text: Text<(), Self::Font>) -> Difference;
 
     /// Returns the horizontal alignment of the [`Paragraph`].
-    fn horizontal_alignment(&self) -> alignment::Horizontal;
+    fn horizontal_alignment(&self) -> Option<alignment::Horizontal>;
 
     /// Returns the vertical alignment of the [`Paragraph`].
     fn vertical_alignment(&self) -> alignment::Vertical;
@@ -108,7 +108,7 @@ impl<P: Paragraph> Plain<P> {
     }
 
     /// Returns the horizontal alignment of the [`Paragraph`].
-    pub fn horizontal_alignment(&self) -> alignment::Horizontal {
+    pub fn horizontal_alignment(&self) -> Option<alignment::Horizontal> {
         self.raw.horizontal_alignment()
     }
 

core/src/widget/text.rs

@@ -67,7 +67,7 @@ where
     line_height: LineHeight,
     width: Length,
     height: Length,
-    horizontal_alignment: alignment::Horizontal,
+    horizontal_alignment: Option<alignment::Horizontal>,
     vertical_alignment: alignment::Vertical,
     font: Option<Renderer::Font>,
     shaping: Shaping,
@@ -89,7 +89,7 @@ where
             font: None,
             width: Length::Shrink,
             height: Length::Shrink,
-            horizontal_alignment: alignment::Horizontal::Left,
+            horizontal_alignment: None,
             vertical_alignment: alignment::Vertical::Top,
             shaping: Shaping::default(),
             wrapping: Wrapping::default(),
@@ -140,7 +140,7 @@ where
         mut self,
         alignment: impl Into<alignment::Horizontal>,
     ) -> Self {
-        self.horizontal_alignment = alignment.into();
+        self.horizontal_alignment = Some(alignment.into());
         self
     }
 
@@ -290,7 +290,7 @@ pub fn layout<Renderer>(
     line_height: LineHeight,
     size: Option<Pixels>,
     font: Option<Renderer::Font>,
-    horizontal_alignment: alignment::Horizontal,
+    horizontal_alignment: Option<alignment::Horizontal>,
     vertical_alignment: alignment::Vertical,
     shaping: Shaping,
     wrapping: Wrapping,
@@ -345,9 +345,9 @@ pub fn draw<Renderer>(
     let bounds = layout.bounds();
 
     let x = match paragraph.horizontal_alignment() {
-        alignment::Horizontal::Left => bounds.x,
+        None | Some(alignment::Horizontal::Left) => bounds.x,
-        alignment::Horizontal::Center => bounds.center_x(),
+        Some(alignment::Horizontal::Center) => bounds.center_x(),
-        alignment::Horizontal::Right => bounds.x + bounds.width,
+        Some(alignment::Horizontal::Right) => bounds.x + bounds.width,
     };
 
     let y = match paragraph.vertical_alignment() {

graphics/src/geometry/text.rs

@@ -10,11 +10,14 @@ pub struct Text {
     /// The contents of the text
     pub content: String,
     /// The position of the text relative to the alignment properties.
+    ///
     /// By default, this position will be relative to the top-left corner coordinate meaning that
     /// if the horizontal and vertical alignments are unchanged, this property will tell where the
     /// top-left corner of the text should be placed.
+    ///
     /// By changing the horizontal_alignment and vertical_alignment properties, you are are able to
     /// change what part of text is placed at this positions.
+    ///
     /// For example, when the horizontal_alignment and vertical_alignment are set to Center, the
     /// center of the text will be placed at the given position NOT the top-left coordinate.
     pub position: Point,

graphics/src/text.rs

@@ -54,7 +54,7 @@ pub enum Text {
         /// The font of the text.
         font: Font,
         /// The horizontal alignment of the text.
-        horizontal_alignment: alignment::Horizontal,
+        horizontal_alignment: Option<alignment::Horizontal>,
         /// The vertical alignment of the text.
         vertical_alignment: alignment::Vertical,
         /// The shaping strategy of the text.
@@ -84,7 +84,7 @@ impl Text {
                 Rectangle::new(*position, paragraph.min_bounds)
                     .intersection(clip_bounds)
                     .map(|bounds| bounds * *transformation),
-                Some(paragraph.horizontal_alignment),
+                paragraph.horizontal_alignment,
                 Some(paragraph.vertical_alignment),
             ),
             Text::Editor {
@@ -108,7 +108,7 @@ impl Text {
                 ..
             } => (
                 bounds.intersection(clip_bounds),
-                Some(*horizontal_alignment),
+                *horizontal_alignment,
                 Some(*vertical_alignment),
             ),
             Text::Raw { raw, .. } => (Some(raw.clip_bounds), None, None),
@@ -242,15 +242,19 @@ impl PartialEq for Raw {
 }
 
 /// Measures the dimensions of the given [`cosmic_text::Buffer`].
-pub fn measure(buffer: &cosmic_text::Buffer) -> Size {
+pub fn measure(buffer: &cosmic_text::Buffer) -> (Size, bool) {
-    let (width, height) =
+    let (width, height, has_rtl) = buffer.layout_runs().fold(
-        buffer
+        (0.0, 0.0, false),
-            .layout_runs()
+        |(width, height, has_rtl), run| {
-            .fold((0.0, 0.0), |(width, height), run| {
+            (
-                (run.line_w.max(width), height + run.line_height)
+                run.line_w.max(width),
-            });
+                height + run.line_height,
+                has_rtl || run.rtl,
+            )
+        },
+    );
 
-    Size::new(width, height)
+    (Size::new(width, height), has_rtl)
 }
 
 /// Returns the attributes of the given [`Font`].
@@ -309,6 +313,14 @@ fn to_style(style: font::Style) -> cosmic_text::Style {
     }
 }
 
+fn to_align(alignment: alignment::Horizontal) -> cosmic_text::Align {
+    match alignment {
+        alignment::Horizontal::Left => cosmic_text::Align::Left,
+        alignment::Horizontal::Center => cosmic_text::Align::Center,
+        alignment::Horizontal::Right => cosmic_text::Align::Right,
+    }
+}
+
 /// Converts some [`Shaping`] strategy to a [`cosmic_text::Shaping`] strategy.
 pub fn to_shaping(shaping: Shaping) -> cosmic_text::Shaping {
     match shaping {

graphics/src/text/cache.rs

@@ -58,7 +58,16 @@ impl Cache {
                 text::to_shaping(key.shaping),
             );
 
-            let bounds = text::measure(&buffer);
+            let (bounds, has_rtl) = text::measure(&buffer);
+
+            if has_rtl {
+                buffer.set_size(
+                    font_system,
+                    Some(bounds.width),
+                    Some(bounds.height),
+                );
+            }
+
             let _ = entry.insert(Entry {
                 buffer,
                 min_bounds: bounds,

graphics/src/text/editor.rs

@@ -450,7 +450,10 @@ impl editor::Editor for Editor {
     fn min_bounds(&self) -> Size {
         let internal = self.internal();
 
-        text::measure(buffer_from_editor(&internal.editor))
+        let (bounds, _has_rtl) =
+            text::measure(buffer_from_editor(&internal.editor));
+
+        bounds
     }
 
     fn update(

graphics/src/text/paragraph.rs

@@ -18,7 +18,7 @@ struct Internal {
     font: Font,
     shaping: Shaping,
     wrapping: Wrapping,
-    horizontal_alignment: alignment::Horizontal,
+    horizontal_alignment: Option<alignment::Horizontal>,
     vertical_alignment: alignment::Vertical,
     bounds: Size,
     min_bounds: Size,
@@ -89,7 +89,8 @@ impl core::text::Paragraph for Paragraph {
             text::to_shaping(text.shaping),
         );
 
-        let min_bounds = text::measure(&buffer);
+        let min_bounds =
+            align(&mut buffer, &mut font_system, text.horizontal_alignment);
 
         Self(Arc::new(Internal {
             buffer,
@@ -159,7 +160,8 @@ impl core::text::Paragraph for Paragraph {
             None,
         );
 
-        let min_bounds = text::measure(&buffer);
+        let min_bounds =
+            align(&mut buffer, &mut font_system, text.horizontal_alignment);
 
         Self(Arc::new(Internal {
             buffer,
@@ -186,8 +188,10 @@ impl core::text::Paragraph for Paragraph {
             Some(new_bounds.height),
         );
 
+        let (min_bounds, _has_rtl) = text::measure(&paragraph.buffer);
+
         paragraph.bounds = new_bounds;
-        paragraph.min_bounds = text::measure(&paragraph.buffer);
+        paragraph.min_bounds = min_bounds;
     }
 
     fn compare(&self, text: Text<()>) -> core::text::Difference {
@@ -212,7 +216,7 @@ impl core::text::Paragraph for Paragraph {
         }
     }
 
-    fn horizontal_alignment(&self) -> alignment::Horizontal {
+    fn horizontal_alignment(&self) -> Option<alignment::Horizontal> {
         self.internal().horizontal_alignment
     }
 
@@ -354,6 +358,42 @@ impl core::text::Paragraph for Paragraph {
     }
 }
 
+fn align(
+    buffer: &mut cosmic_text::Buffer,
+    font_system: &mut text::FontSystem,
+    align_x: Option<alignment::Horizontal>,
+) -> Size {
+    let (min_bounds, has_rtl) = text::measure(buffer);
+    let mut needs_relayout = has_rtl;
+
+    if let Some(align_x) = align_x {
+        let has_multiple_lines = buffer.lines.len() > 1
+            || buffer.lines.first().is_some_and(|line| {
+                line.layout_opt().is_some_and(|layout| layout.len() > 1)
+            });
+
+        if has_multiple_lines {
+            for line in &mut buffer.lines {
+                let _ = line.set_align(Some(text::to_align(align_x)));
+            }
+
+            needs_relayout = true;
+        }
+    }
+
+    if needs_relayout {
+        log::trace!("Relayouting paragraph...");
+
+        buffer.set_size(
+            font_system.raw(),
+            Some(min_bounds.width),
+            Some(min_bounds.height),
+        );
+    }
+
+    min_bounds
+}
+
 impl Default for Paragraph {
     fn default() -> Self {
         Self(Arc::new(Internal::default()))
@@ -397,7 +437,7 @@ impl Default for Internal {
             font: Font::default(),
             shaping: Shaping::default(),
             wrapping: Wrapping::default(),
-            horizontal_alignment: alignment::Horizontal::Left,
+            horizontal_alignment: None,
             vertical_alignment: alignment::Vertical::Top,
             bounds: Size::ZERO,
             min_bounds: Size::ZERO,
@@ -413,7 +453,7 @@ pub struct Weak {
     /// The minimum bounds of the [`Paragraph`].
     pub min_bounds: Size,
     /// The horizontal alignment of the [`Paragraph`].
-    pub horizontal_alignment: alignment::Horizontal,
+    pub horizontal_alignment: Option<alignment::Horizontal>,
     /// The vertical alignment of the [`Paragraph`].
     pub vertical_alignment: alignment::Vertical,
 }

tiny_skia/src/geometry.rs

@@ -231,7 +231,7 @@ impl geometry::frame::Backend for Frame {
                 size,
                 line_height: line_height.to_absolute(size),
                 font: text.font,
-                horizontal_alignment: text.horizontal_alignment,
+                horizontal_alignment: Some(text.horizontal_alignment),
                 vertical_alignment: text.vertical_alignment,
                 shaping: text.shaping,
                 clip_bounds: Rectangle::with_size(Size::INFINITY),

tiny_skia/src/text.rs

@@ -92,7 +92,7 @@ impl Pipeline {
             editor.buffer(),
             Rectangle::new(position, editor.bounds()),
             color,
-            alignment::Horizontal::Left,
+            None,
             alignment::Vertical::Top,
             pixels,
             clip_mask,
@@ -108,7 +108,7 @@ impl Pipeline {
         size: Pixels,
         line_height: Pixels,
         font: Font,
-        horizontal_alignment: alignment::Horizontal,
+        horizontal_alignment: Option<alignment::Horizontal>,
         vertical_alignment: alignment::Vertical,
         shaping: Shaping,
         pixels: &mut tiny_skia::PixmapMut<'_>,
@@ -177,7 +177,7 @@ impl Pipeline {
                 ),
             ),
             color,
-            alignment::Horizontal::Left,
+            None,
             alignment::Vertical::Top,
             pixels,
             clip_mask,
@@ -197,7 +197,7 @@ fn draw(
     buffer: &cosmic_text::Buffer,
     bounds: Rectangle,
     color: Color,
-    horizontal_alignment: alignment::Horizontal,
+    horizontal_alignment: Option<alignment::Horizontal>,
     vertical_alignment: alignment::Vertical,
     pixels: &mut tiny_skia::PixmapMut<'_>,
     clip_mask: Option<&tiny_skia::Mask>,
@@ -206,9 +206,9 @@ fn draw(
     let bounds = bounds * transformation;
 
     let x = match horizontal_alignment {
-        alignment::Horizontal::Left => bounds.x,
+        None | Some(alignment::Horizontal::Left) => bounds.x,
-        alignment::Horizontal::Center => bounds.x - bounds.width / 2.0,
+        Some(alignment::Horizontal::Center) => bounds.x - bounds.width / 2.0,
-        alignment::Horizontal::Right => bounds.x - bounds.width,
+        Some(alignment::Horizontal::Right) => bounds.x - bounds.width,
     };
 
     let y = match vertical_alignment {

wgpu/src/geometry.rs

@@ -336,7 +336,7 @@ impl geometry::frame::Backend for Frame {
                 size,
                 line_height: line_height.to_absolute(size),
                 font: text.font,
-                horizontal_alignment: text.horizontal_alignment,
+                horizontal_alignment: Some(text.horizontal_alignment),
                 vertical_alignment: text.vertical_alignment,
                 shaping: text.shaping,
                 clip_bounds: self.clip_bounds,

wgpu/src/lib.rs

@@ -417,7 +417,7 @@ impl Renderer {
                         size: Pixels(20.0),
                         line_height: core::text::LineHeight::default(),
                         font: Font::MONOSPACE,
-                        horizontal_alignment: alignment::Horizontal::Left,
+                        horizontal_alignment: None,
                         vertical_alignment: alignment::Vertical::Top,
                         shaping: core::text::Shaping::Basic,
                         wrapping: core::text::Wrapping::Word,

wgpu/src/text.rs

@@ -540,7 +540,7 @@ fn prepare(
                     (
                         editor.buffer(),
                         Rectangle::new(*position, editor.bounds()),
-                        alignment::Horizontal::Left,
+                        None,
                         alignment::Vertical::Top,
                         *color,
                         *clip_bounds,
@@ -591,7 +591,7 @@ fn prepare(
                                 height.unwrap_or(layer_bounds.height),
                             ),
                         ),
-                        alignment::Horizontal::Left,
+                        None,
                         alignment::Vertical::Top,
                         raw.color,
                         raw.clip_bounds,
@@ -603,9 +603,11 @@ fn prepare(
             let bounds = bounds * transformation * layer_transformation;
 
             let left = match horizontal_alignment {
-                alignment::Horizontal::Left => bounds.x,
+                None | Some(alignment::Horizontal::Left) => bounds.x,
-                alignment::Horizontal::Center => bounds.x - bounds.width / 2.0,
+                Some(alignment::Horizontal::Center) => {
-                alignment::Horizontal::Right => bounds.x - bounds.width,
+                    bounds.x - bounds.width / 2.0
+                }
+                Some(alignment::Horizontal::Right) => bounds.x - bounds.width,
             };
 
             let top = match vertical_alignment {

widget/src/checkbox.rs

@@ -293,7 +293,7 @@ where
                     self.text_line_height,
                     self.text_size,
                     self.font,
-                    alignment::Horizontal::Left,
+                    None,
                     alignment::Vertical::Top,
                     self.text_shaping,
                     self.text_wrapping,
@@ -416,7 +416,9 @@ where
                         size,
                         line_height: *line_height,
                         bounds: bounds.size(),
-                        horizontal_alignment: alignment::Horizontal::Center,
+                        horizontal_alignment: Some(
+                            alignment::Horizontal::Center,
+                        ),
                         vertical_alignment: alignment::Vertical::Center,
                         shaping: *shaping,
                         wrapping: text::Wrapping::default(),

widget/src/overlay/menu.rs

@@ -552,7 +552,7 @@ where
                     size: text_size,
                     line_height: self.text_line_height,
                     font: self.font.unwrap_or_else(|| renderer.default_font()),
-                    horizontal_alignment: alignment::Horizontal::Left,
+                    horizontal_alignment: None,
                     vertical_alignment: alignment::Vertical::Center,
                     shaping: self.text_shaping,
                     wrapping: text::Wrapping::default(),

widget/src/pick_list.rs

@@ -371,7 +371,7 @@ where
             size: text_size,
             line_height: self.text_line_height,
             font,
-            horizontal_alignment: alignment::Horizontal::Left,
+            horizontal_alignment: None,
             vertical_alignment: alignment::Vertical::Center,
             shaping: self.text_shaping,
             wrapping: text::Wrapping::default(),
@@ -639,7 +639,7 @@ where
                         bounds.width,
                         f32::from(line_height.to_absolute(size)),
                     ),
-                    horizontal_alignment: alignment::Horizontal::Right,
+                    horizontal_alignment: Some(alignment::Horizontal::Right),
                     vertical_alignment: alignment::Vertical::Center,
                     shaping,
                     wrapping: text::Wrapping::default(),
@@ -669,7 +669,7 @@ where
                         bounds.width - self.padding.horizontal(),
                         f32::from(self.text_line_height.to_absolute(text_size)),
                     ),
-                    horizontal_alignment: alignment::Horizontal::Left,
+                    horizontal_alignment: None,
                     vertical_alignment: alignment::Vertical::Center,
                     shaping: self.text_shaping,
                     wrapping: text::Wrapping::default(),

widget/src/radio.rs

@@ -314,7 +314,7 @@ where
                     self.text_line_height,
                     self.text_size,
                     self.font,
-                    alignment::Horizontal::Left,
+                    None,
                     alignment::Vertical::Top,
                     self.text_shaping,
                     self.text_wrapping,

widget/src/text/rich.rs

@@ -31,7 +31,7 @@ pub struct Rich<
     width: Length,
     height: Length,
     font: Option<Renderer::Font>,
-    align_x: alignment::Horizontal,
+    align_x: Option<alignment::Horizontal>,
     align_y: alignment::Vertical,
     wrapping: Wrapping,
     class: Theme::Class<'a>,
@@ -56,7 +56,7 @@ where
             width: Length::Shrink,
             height: Length::Shrink,
             font: None,
-            align_x: alignment::Horizontal::Left,
+            align_x: None,
             align_y: alignment::Vertical::Top,
             wrapping: Wrapping::default(),
             class: Theme::default(),
@@ -116,7 +116,7 @@ where
         mut self,
         alignment: impl Into<alignment::Horizontal>,
     ) -> Self {
-        self.align_x = alignment.into();
+        self.align_x = Some(alignment.into());
         self
     }
 
@@ -476,7 +476,7 @@ fn layout<Link, Renderer>(
     line_height: LineHeight,
     size: Option<Pixels>,
     font: Option<Renderer::Font>,
-    horizontal_alignment: alignment::Horizontal,
+    horizontal_alignment: Option<alignment::Horizontal>,
     vertical_alignment: alignment::Vertical,
     wrapping: Wrapping,
 ) -> layout::Node

widget/src/text_editor.rs

@@ -955,7 +955,7 @@ where
                             .unwrap_or_else(|| renderer.default_size()),
                         line_height: self.line_height,
                         font,
-                        horizontal_alignment: alignment::Horizontal::Left,
+                        horizontal_alignment: None,
                         vertical_alignment: alignment::Vertical::Top,
                         shaping: text::Shaping::Advanced,
                         wrapping: self.wrapping,

widget/src/text_input.rs

@@ -319,7 +319,7 @@ where
             content: self.placeholder.as_str(),
             bounds: Size::new(f32::INFINITY, text_bounds.height),
             size: text_size,
-            horizontal_alignment: alignment::Horizontal::Left,
+            horizontal_alignment: None,
             vertical_alignment: alignment::Vertical::Center,
             shaping: text::Shaping::Advanced,
             wrapping: text::Wrapping::default(),
@@ -344,7 +344,7 @@ where
                 font: icon.font,
                 size: icon.size.unwrap_or_else(|| renderer.default_size()),
                 bounds: Size::new(f32::INFINITY, text_bounds.height),
-                horizontal_alignment: alignment::Horizontal::Center,
+                horizontal_alignment: Some(alignment::Horizontal::Center),
                 vertical_alignment: alignment::Vertical::Center,
                 shaping: text::Shaping::Advanced,
                 wrapping: text::Wrapping::default(),
@@ -1727,7 +1727,7 @@ fn replace_paragraph<Renderer>(
         content: &value.to_string(),
         bounds: Size::new(f32::INFINITY, text_bounds.height),
         size: text_size,
-        horizontal_alignment: alignment::Horizontal::Left,
+        horizontal_alignment: None,
         vertical_alignment: alignment::Vertical::Center,
         shaping: text::Shaping::Advanced,
         wrapping: text::Wrapping::default(),

widget/src/toggler.rs

@@ -93,7 +93,7 @@ pub struct Toggler<
     size: f32,
     text_size: Option<Pixels>,
     text_line_height: text::LineHeight,
-    text_alignment: alignment::Horizontal,
+    text_alignment: Option<alignment::Horizontal>,
     text_shaping: text::Shaping,
     text_wrapping: text::Wrapping,
     spacing: f32,
@@ -127,7 +127,7 @@ where
             size: Self::DEFAULT_SIZE,
             text_size: None,
             text_line_height: text::LineHeight::default(),
-            text_alignment: alignment::Horizontal::Left,
+            text_alignment: None,
             text_shaping: text::Shaping::default(),
             text_wrapping: text::Wrapping::default(),
             spacing: Self::DEFAULT_SIZE / 2.0,
@@ -195,8 +195,11 @@ where
     }
 
     /// Sets the horizontal alignment of the text of the [`Toggler`]
-    pub fn text_alignment(mut self, alignment: alignment::Horizontal) -> Self {
+    pub fn text_alignment(
-        self.text_alignment = alignment;
+        mut self,
+        alignment: impl Into<alignment::Horizontal>,
+    ) -> Self {
+        self.text_alignment = Some(alignment.into());
         self
     }
 

winit/src/program/window_manager.rs

@@ -338,7 +338,7 @@ where
                     .unwrap_or_else(|| renderer.default_size()),
                 line_height: text::LineHeight::default(),
                 font: renderer.default_font(),
-                horizontal_alignment: alignment::Horizontal::Left,
+                horizontal_alignment: None,
                 vertical_alignment: alignment::Vertical::Top,
                 shaping: text::Shaping::Advanced,
                 wrapping: text::Wrapping::None,