Merge pull request #590 from kas-gui/push-ynyyunnrluqz

Fix several sizing bugs

Author: dhardy

Cargo.toml

@@ -167,3 +167,7 @@ members = [
     "examples/mandlebrot",
     "examples/text-editor",
 ]
+
+[patch.crates-io.kas-text]
+git = "https://github.com/kas-gui/kas-text.git"
+rev = "d2965eb7"

crates/kas-core/src/runner/window.rs

@@ -593,6 +593,23 @@ impl<A: AppData, G: GraphicsInstance, T: Theme<G::Shared>> Window<A, G, T> {
         debug_assert!(solve_cache.min(false) <= solve_cache.ideal(false));
         self.widget.resize_popups(&mut cx, data);
 
+        // Update window size restrictions: the new width may have changed height requirements
+        let (restrict_min, restrict_max) = self.widget.properties().restrictions();
+        window.set_min_inner_size(restrict_min.then(|| {
+            window
+                .solve_cache
+                .min(true)
+                .as_physical()
+                .to_logical::<f64>(window.scale_factor())
+        }));
+        window.set_max_inner_size(restrict_max.then(|| {
+            window
+                .solve_cache
+                .ideal(true)
+                .as_physical()
+                .to_logical::<f64>(window.scale_factor())
+        }));
+
         window.set_visible(true);
         window.request_redraw();
         log::trace!(

crates/kas-core/src/text/mod.rs

@@ -14,8 +14,8 @@
 //! [KAS Text]: https://github.com/kas-gui/kas-text/
 
 pub use kas_text::{
-    Align, DPU, Direction, Effect, EffectFlags, MarkerPos, MarkerPosIter, NotReady, OwningVecIter,
-    Range, Status, Text, TextDisplay, Vec2, fonts, format,
+    Align, DPU, Direction, Effect, EffectFlags, Line, MarkerPos, MarkerPosIter, NotReady,
+    OwningVecIter, Status, Text, TextDisplay, Vec2, fonts, format,
 };
 
 mod selection;

crates/kas-core/src/theme/dimensions.rs

@@ -353,7 +353,10 @@ impl<D: 'static> ThemeSize for Window<D> {
                 SizeRules::new(bound, bound, Stretch::Filler)
             }
         } else {
-            let wrap_width = axis.other().map(|w| w.cast()).unwrap_or(f32::INFINITY);
+            let wrap_width = wrap
+                .then(|| axis.other().map(|w| w.cast()))
+                .flatten()
+                .unwrap_or(f32::INFINITY);
             let bound: i32 = text.measure_height(wrap_width).cast_ceil();
             SizeRules::new(bound, bound, Stretch::Filler)
         };

crates/kas-core/src/theme/size.rs

@@ -235,6 +235,9 @@ pub trait ThemeSize {
     fn text_configure(&self, text: &mut dyn SizableText, class: TextClass);
 
     /// Get [`SizeRules`] for a text element
+    ///
+    /// Calculates required text dimensions according to the `class` and uses
+    /// theme-defined margins.
     fn text_rules(&self, text: &mut dyn SizableText, class: TextClass, axis: AxisInfo)
     -> SizeRules;
 }

crates/kas-core/src/theme/text.rs

@@ -15,6 +15,7 @@ use crate::text::fonts::FontSelector;
 use crate::text::format::FormattableText;
 use crate::text::*;
 use crate::{Action, Layout};
+use std::num::NonZeroUsize;
 
 /// Text type-setting object (theme aware)
 ///
@@ -442,13 +443,15 @@ impl<T: FormattableText> Text<T> {
         self.display.measure_width(max_width)
     }
 
-    /// Measure required vertical height
+    /// Measure required vertical height, wrapping as configured
+    ///
+    /// Stops after `max_lines`, if provided.
     ///
     /// May partially prepare the text for display, but does not otherwise
     /// modify `self`.
-    pub fn measure_height(&mut self, wrap_width: f32) -> f32 {
+    pub fn measure_height(&mut self, wrap_width: f32, max_lines: Option<NonZeroUsize>) -> f32 {
         self.prepare_runs();
-        self.display.measure_height(wrap_width)
+        self.display.measure_height(wrap_width, max_lines)
     }
 
     /// Prepare text for display, as necessary
@@ -552,6 +555,20 @@ impl<T: FormattableText> Text<T> {
         Ok(self.wrapped_display()?.num_lines())
     }
 
+    /// Get line properties
+    #[inline]
+    pub fn get_line(&self, index: usize) -> Result<Option<&Line>, NotReady> {
+        Ok(self.wrapped_display()?.get_line(index))
+    }
+
+    /// Iterate over line properties
+    ///
+    /// [Requires status][Self#status-of-preparation]: lines have been wrapped.
+    #[inline]
+    pub fn lines(&self) -> Result<impl Iterator<Item = &Line>, NotReady> {
+        Ok(self.wrapped_display()?.lines())
+    }
+
     /// Find the line containing text `index`
     ///
     /// See [`TextDisplay::find_line`].
@@ -563,14 +580,6 @@ impl<T: FormattableText> Text<T> {
         Ok(self.wrapped_display()?.find_line(index))
     }
 
-    /// Get the range of a line, by line number
-    ///
-    /// See [`TextDisplay::line_range`].
-    #[inline]
-    pub fn line_range(&self, line: usize) -> Result<Option<std::ops::Range<usize>>, NotReady> {
-        Ok(self.wrapped_display()?.line_range(line))
-    }
-
     /// Get the directionality of the current line
     ///
     /// See [`TextDisplay::line_is_rtl`].
@@ -705,6 +714,6 @@ impl<T: FormattableText> SizableText for Text<T> {
     }
 
     fn measure_height(&mut self, wrap_width: f32) -> f32 {
-        Text::measure_height(self, wrap_width)
+        Text::measure_height(self, wrap_width, None)
     }
 }

crates/kas-widgets/src/edit/edit_field.rs

@@ -102,12 +102,15 @@ mod EditField {
                 let dpem = cx.dpem();
                 min = (self.width.0 * dpem).cast_ceil();
                 ideal = (self.width.1 * dpem).cast_ceil();
+            } else if let Some(width) = axis.other() {
+                // Use the height of the first line as a reference
+                let height = self
+                    .text
+                    .measure_height(width.cast(), std::num::NonZero::new(1));
+                min = (self.lines.0 * height).cast_ceil();
+                ideal = (self.lines.1 * height).cast_ceil();
             } else {
-                // TODO: line height depends on the font; 1em is not a good
-                // approximation. This code also misses inter-line spacing.
-                let dpem = cx.dpem();
-                min = (self.lines.0 * dpem).cast_ceil();
-                ideal = (self.lines.1 * dpem).cast_ceil();
+                unreachable!()
             };
 
             let rules = self.text.size_rules(cx, axis);

crates/kas-widgets/src/scroll_label.rs

@@ -46,8 +46,13 @@ mod SelectableText {
     impl Layout for Self {
         fn size_rules(&mut self, cx: &mut SizeCx, axis: AxisInfo) -> SizeRules {
             let mut rules = kas::MacroDefinedLayout::size_rules(self, cx, axis);
-            if axis.is_vertical() {
-                rules.reduce_min_to(cx.dpem().cast_ceil());
+            if axis.is_vertical()
+                && let Some(width) = axis.other()
+            {
+                let height = self
+                    .text
+                    .measure_height(width.cast(), std::num::NonZero::new(3));
+                rules.reduce_min_to(height.cast_ceil());
             }
             rules
         }

crates/kas-widgets/src/stack.rs

@@ -88,13 +88,23 @@ mod Stack {
 
     impl Layout for Self {
         fn size_rules(&mut self, cx: &mut SizeCx, axis: AxisInfo) -> SizeRules {
-            let mut rules = SizeRules::EMPTY;
-            for entry in self.widgets.iter_mut() {
+            let (mut min, mut ideal) = (0, 0);
+            let mut m = (0, 0);
+            let mut stretch = Stretch::None;
+
+            for (i, entry) in self.widgets.iter_mut().enumerate() {
                 if entry.1 != usize::MAX {
-                    rules = rules.max(entry.0.size_rules(cx, axis));
+                    let rules = entry.0.size_rules(cx, axis);
+                    ideal = ideal.max(rules.ideal_size());
+                    m = (m.0.max(rules.margins().0), m.1.max(rules.margins().1));
+                    stretch = stretch.max(rules.stretch());
+                    if i == self.active {
+                        min = rules.min_size();
+                    }
                 }
             }
-            rules
+
+            SizeRules::new(min, ideal, stretch).with_margins(m)
         }
 
         fn set_rect(&mut self, cx: &mut SizeCx, rect: Rect, hints: AlignHints) {

examples/gallery.rs

@@ -723,10 +723,15 @@ KAS_CONFIG_MODE=readwrite
     )
     .unwrap();
 
-    let ui = column![ScrollLabel::new(desc), Separator::new(), EventConfig::new()]
-        .map_any()
-        .on_update(|cx, _, data: &AppData| cx.set_disabled(data.disabled));
-    Page::new(ui)
+    let ui = column![
+        ScrollLabel::new(desc),
+        Separator::new(),
+        ScrollBarRegion::new(EventConfig::new())
+    ];
+    Page::new(
+        ui.map_any()
+            .on_update(|cx, _, data: &AppData| cx.set_disabled(data.disabled)),
+    )
 }
 
 fn main() -> kas::runner::Result<()> {