Move generalization/specialization methods 🚚

4 files changed, 43 insertions, 17 deletions

diff --git a/src/layout/flex.rs b/src/layout/flex.rs
index c136ad0d..a65391da 100644
--- a/src/layout/flex.rs
+++ b/src/layout/flex.rs
@@ -129,7 +129,7 @@ impl FlexLayouter {
     /// Layout a content box into the current flex run or start a new run if
     /// it does not fit.
     fn layout_box(&mut self, boxed: Layout) -> LayoutResult<()> {
-        let size = boxed.dimensions.generalized(self.ctx.axes);
+        let size = self.ctx.axes.generalize(boxed.dimensions);
 
         let space = self.space.unwrap_or(Size::zero());
         let new_run_size = self.run.size.x + space + size.x;
@@ -166,14 +166,14 @@ impl FlexLayouter {
     fn finish_run(&mut self) -> LayoutResult<()> {
         let mut actions = LayoutActionList::new();
         for (x, layout) in self.run.content.drain(..) {
-            let position = Size2D::with_x(x).specialized(self.ctx.axes);
+            let position = self.ctx.axes.specialize(Size2D::with_x(x));
             actions.add_layout(position, layout);
         }
 
         self.run.size.y += self.ctx.flex_spacing;
 
         self.stack.add(Layout {
-            dimensions: self.run.size.specialized(self.ctx.axes),
+            dimensions: self.ctx.axes.specialize(self.run.size),
             actions: actions.into_vec(),
             debug_render: false,
         })?;
@@ -183,6 +183,11 @@ impl FlexLayouter {
         Ok(())
     }
 
+    /// Update the axes in use by this flex layouter.
+    pub fn set_axes(&self, axes: LayoutAxes) {
+
+    }
+
     /// This layouter's context.
     pub fn ctx(&self) -> FlexContext {
         self.ctx
diff --git a/src/layout/mod.rs b/src/layout/mod.rs
index 2bafd792..442747b5 100644
--- a/src/layout/mod.rs
+++ b/src/layout/mod.rs
@@ -199,10 +199,30 @@ pub struct LayoutAxes {
 }
 
 impl LayoutAxes {
+    /// Returns the generalized version of a `Size2D` dependent on
+    /// the layouting axes, that is:
+    /// - The x coordinate describes the primary axis instead of the horizontal one.
+    /// - The y coordinate describes the secondary axis instead of the vertical one.
+    pub fn generalize(&self, space: Size2D) -> Size2D {
+        if self.primary.axis.is_horizontal() {
+            space
+        } else {
+            Size2D { x: space.y, y: space.x }
+        }
+    }
+
+    /// Returns the specialized version of this generalized Size2D.
+    /// (Inverse to `generalized`).
+    pub fn specialize(&self, space: Size2D) -> Size2D {
+        // In fact, generalized is its own inverse. For reasons of clarity
+        // at the call site, we still have this second function.
+        self.generalize(space)
+    }
+
     /// The position of the anchor specified by the two aligned axes
     /// in the given generalized space.
-    pub fn anchor(&self, area: Size2D) -> Size2D {
-        Size2D::new(self.primary.anchor(area.x), self.secondary.anchor(area.y))
+    pub fn anchor(&self, space: Size2D) -> Size2D {
+        Size2D::new(self.primary.anchor(space.x), self.secondary.anchor(space.y))
     }
 }
 
diff --git a/src/layout/stacked.rs b/src/layout/stacked.rs
index cc6caa5e..91bb09b5 100644
--- a/src/layout/stacked.rs
+++ b/src/layout/stacked.rs
@@ -29,7 +29,7 @@ pub struct StackContext {
 impl StackLayouter {
     /// Create a new stack layouter.
     pub fn new(ctx: StackContext) -> StackLayouter {
-        let usable = ctx.spaces[0].usable().generalized(ctx.axes);
+        let usable = ctx.axes.generalize(ctx.spaces[0].usable());
         StackLayouter {
             ctx,
             layouts: MultiLayout::new(),
@@ -44,7 +44,7 @@ impl StackLayouter {
 
     /// Add a sublayout.
     pub fn add(&mut self, layout: Layout) -> LayoutResult<()> {
-        let size = layout.dimensions.generalized(self.ctx.axes);
+        let size = self.ctx.axes.generalize(layout.dimensions);
         let mut new_dimensions = self.size_with(size);
 
         // Search for a suitable space to insert the box.
@@ -114,7 +114,7 @@ impl StackLayouter {
 
         for (offset, layout_anchor, layout) in self.boxes.drain(..) {
             let general_position = anchor - layout_anchor + Size2D::with_y(offset * factor);
-            let position = start + general_position.specialized(self.ctx.axes);
+            let position = start + self.ctx.axes.specialize(general_position);
 
             actions.add_layout(position, layout);
         }
@@ -137,11 +137,16 @@ impl StackLayouter {
     /// content is added to it.
     fn start_new_space(&mut self, include_empty: bool) {
         self.active_space = self.next_space();
-        self.usable = self.ctx.spaces[self.active_space].usable().generalized(self.ctx.axes);
+        self.usable = self.ctx.axes.generalize(self.ctx.spaces[self.active_space].usable());
         self.dimensions = start_dimensions(self.usable, self.ctx.axes);
         self.include_empty = include_empty;
     }
 
+    /// Update the axes in use by this stack layouter.
+    pub fn set_axes(&self, axes: LayoutAxes) {
+
+    }
+
     /// This layouter's context.
     pub fn ctx(&self) -> StackContext {
         self.ctx
@@ -154,9 +159,9 @@ impl StackLayouter {
 
     /// The remaining spaces for new layouts in the current space.
     pub fn remaining(&self, shrink_to_fit: bool) -> LayoutSpaces {
+        let remains = Size2D::new(self.usable.x, self.usable.y - self.dimensions.y);
         let mut spaces = smallvec![LayoutSpace {
-            dimensions: Size2D::new(self.usable.x, self.usable.y - self.dimensions.y)
-                .specialized(self.ctx.axes),
+            dimensions: self.ctx.axes.specialize(remains),
             padding: SizeBox::zero(),
             shrink_to_fit,
         }];
diff --git a/src/layout/tree.rs b/src/layout/tree.rs
index ca2051f4..2957420d 100644
--- a/src/layout/tree.rs
+++ b/src/layout/tree.rs
@@ -100,12 +100,8 @@ impl<'a, 'p> TreeLayouter<'a, 'p> {
 
             Command::SetStyle(style) => *self.style.to_mut() = style,
             Command::SetAxes(axes) => {
-                if axes.secondary != self.ctx.axes.secondary {
-                    self.stack.set_axis(axes.secondary);
-                } else if axes.primary != self.ctx.axes.primary {
-                    self.flex.set_axis(axes.primary);
-                }
-
+                self.stack.set_axes(axes);
+                self.flex.set_axes(axes);
                 self.ctx.axes = axes;
             }
         }