move stuff out

hui/src/element/builtin/image.rs

@@ -4,7 +4,7 @@ use crate::{
   background::BackgroundColor,
   draw::{ImageHandle, RoundedCorners, UiDrawCommand},
   element::{MeasureContext, ProcessContext, UiElement},
-  layout::{Size, Size2d},
+  layout::{compute_size, Size, Size2d},
   measure::Response,
   rectangle::Corners,
 };
@@ -57,31 +57,18 @@ impl UiElement for Image {
 
   fn measure(&self, ctx: MeasureContext) -> Response {
     let dim = ctx.images.get_size(self.image).expect("invalid image handle");
+    let pre_size = compute_size(ctx.layout, self.size, dim.as_vec2());
     Response {
-      size: vec2(
-        match self.size.width {
-          Size::Auto => {
-            match self.size.height {
-              Size::Auto => dim.x as f32,
-              Size::Fraction(f) => ((f * ctx.layout.max_size.y) / dim.y as f32) * dim.x as f32,
-              Size::Static(pixels) => (pixels / dim.y as f32) * dim.x as f32,
-            }
-          },
-          Size::Fraction(percentage) => ctx.layout.max_size.x * percentage,
-          Size::Static(pixels) => pixels,
+      size: compute_size(ctx.layout, self.size, vec2(
+        match self.size.height {
+          Size::Auto => dim.x as f32,
+          _ => (pre_size.y / dim.y as f32) * dim.x as f32,
         },
         match self.size.height {
-          Size::Auto => {
-            match self.size.width {
-              Size::Auto => dim.y as f32,
-              Size::Fraction(f) => ((f * ctx.layout.max_size.x) / dim.x as f32) * dim.y as f32,
-              Size::Static(pixels) => (pixels / dim.x as f32) * dim.y as f32,
-            }
-          },
-          Size::Fraction(percentage) => ctx.layout.max_size.y * percentage,
-          Size::Static(pixels) => pixels,
+          Size::Auto => dim.x as f32,
+          _ => (pre_size.y / dim.y as f32) * dim.x as f32,
         },
-      ),
+      )),
       ..Default::default()
     }
   }

hui/src/element/builtin/progress_bar.rs

@@ -4,7 +4,7 @@ use crate::{
   background::BackgroundColor,
   draw::{RoundedCorners, UiDrawCommand},
   element::{MeasureContext, ProcessContext, UiElement},
-  layout::{Size, Size2d},
+  layout::{compute_size, Size, Size2d},
   measure::Response,
   rectangle::Corners
 };
@@ -55,18 +55,10 @@ impl UiElement for ProgressBar {
 
   fn measure(&self, ctx: MeasureContext) -> Response {
     Response {
-      size: vec2(
-        match self.size.width {
-          Size::Auto => ctx.layout.max_size.x.max(300.),
-          Size::Fraction(p) => ctx.layout.max_size.x * p,
-          Size::Static(p) => p,
-        },
-        match self.size.height {
-          Size::Auto => Self::DEFAULT_HEIGHT,
-          Size::Fraction(p) => ctx.layout.max_size.y * p,
-          Size::Static(p) => p,
-        }
-      ),
+      size: compute_size(ctx.layout, self.size, vec2(
+        ctx.layout.max_size.x.max(300.),
+        Self::DEFAULT_HEIGHT,
+      )),
       hints: Default::default(),
       user_data: None,
       ..Default::default()

hui/src/layout.rs

@@ -1,6 +1,6 @@
 //! element layout, alignment and sizing
 
-use glam::Vec2;
+use glam::{vec2, Vec2};
 
 /// Alignment along a single axis
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Default, PartialOrd, Ord)]
@@ -160,3 +160,19 @@ pub struct LayoutInfo {
   /// (Usually matches direction of the parent container)
   pub direction: Direction,
 }
+
+/// Helper function to calculate the size of an element based on its layout and size information\
+/// Used to help reduce code duplication in the `measure` method of UI elements
+pub fn compute_size(layout: &LayoutInfo, size: Size2d, comfy_size: Vec2) -> Vec2 {
+  let width = match size.width {
+    Size::Auto => comfy_size.x,
+    Size::Fraction(fraction) => layout.max_size.x * fraction,
+    Size::Static(size) => size,
+  };
+  let height = match size.height {
+    Size::Auto => comfy_size.y,
+    Size::Fraction(fraction) => layout.max_size.y * fraction,
+    Size::Static(size) => size,
+  };
+  vec2(width, height)
+}