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Diffstat (limited to 'src/layout/nodes/stack.rs')
| -rw-r--r-- | src/layout/nodes/stack.rs | 206 |
1 files changed, 0 insertions, 206 deletions
diff --git a/src/layout/nodes/stack.rs b/src/layout/nodes/stack.rs deleted file mode 100644 index cca64e62..00000000 --- a/src/layout/nodes/stack.rs +++ /dev/null @@ -1,206 +0,0 @@ -use super::*; - -/// A node that stacks and aligns its children. -/// -/// # Alignment -/// Individual layouts can be aligned at `Start`, `Center` or `End` along both -/// axes. These alignments are with processed with respect to the size of the -/// finished layout and not the total usable size. This means that a later -/// layout can have influence on the position of an earlier one. Consider the -/// following example. -/// ```typst -/// [align: right][A word.] -/// [align: left][A sentence with a couple more words.] -/// ``` -/// The resulting layout looks like this: -/// ```text -/// |--------------------------------------| -/// | A word. | -/// | | -/// | A sentence with a couple more words. | -/// |--------------------------------------| -/// ``` -/// The position of the first aligned box thus depends on the length of the -/// sentence in the second box. -#[derive(Debug, Clone, PartialEq)] -pub struct Stack { - pub dirs: Gen2<Dir>, - pub children: Vec<LayoutNode>, - pub aligns: Gen2<GenAlign>, - pub expand: Spec2<bool>, -} - -#[async_trait(?Send)] -impl Layout for Stack { - async fn layout( - &self, - ctx: &mut LayoutContext, - constraints: LayoutConstraints, - ) -> Vec<LayoutItem> { - let mut items = vec![]; - - let size = constraints.spaces[0].size; - let mut space = StackSpace::new(self.dirs, self.expand, size); - let mut i = 0; - - for child in &self.children { - let child_constraints = LayoutConstraints { - spaces: { - let mut remaining = vec![LayoutSpace { - base: space.full_size, - size: space.usable, - }]; - let next = (i + 1).min(constraints.spaces.len() - 1); - remaining.extend(&constraints.spaces[next ..]); - remaining - }, - repeat: constraints.repeat, - }; - - for item in child.layout(ctx, child_constraints).await { - match item { - LayoutItem::Spacing(spacing) => space.push_spacing(spacing), - LayoutItem::Box(mut boxed, aligns) => { - let mut last = false; - while let Err(back) = space.push_box(boxed, aligns) { - boxed = back; - if last { - break; - } - - items.push(LayoutItem::Box(space.finish(), self.aligns)); - - if i + 1 < constraints.spaces.len() { - i += 1; - } else { - last = true; - } - - let size = constraints.spaces[i].size; - space = StackSpace::new(self.dirs, self.expand, size); - } - } - } - } - } - - items.push(LayoutItem::Box(space.finish(), self.aligns)); - items - } -} - -struct StackSpace { - dirs: Gen2<Dir>, - expand: Spec2<bool>, - boxes: Vec<(BoxLayout, Gen2<GenAlign>)>, - full_size: Size, - usable: Size, - used: Size, - ruler: GenAlign, -} - -impl StackSpace { - fn new(dirs: Gen2<Dir>, expand: Spec2<bool>, size: Size) -> Self { - Self { - dirs, - expand, - boxes: vec![], - full_size: size, - usable: size, - used: Size::ZERO, - ruler: GenAlign::Start, - } - } - - fn push_box( - &mut self, - boxed: BoxLayout, - aligns: Gen2<GenAlign>, - ) -> Result<(), BoxLayout> { - let main = self.dirs.main.axis(); - let cross = self.dirs.cross.axis(); - if aligns.main < self.ruler || !self.usable.fits(boxed.size) { - return Err(boxed); - } - - let size = boxed.size.switch(self.dirs); - *self.used.get_mut(cross) = self.used.get(cross).max(size.cross); - *self.used.get_mut(main) += size.main; - *self.usable.get_mut(main) -= size.main; - self.boxes.push((boxed, aligns)); - self.ruler = aligns.main; - - Ok(()) - } - - fn push_spacing(&mut self, spacing: f64) { - let main = self.dirs.main.axis(); - let max = self.usable.get(main); - let trimmed = spacing.min(max); - *self.used.get_mut(main) += trimmed; - *self.usable.get_mut(main) -= trimmed; - - let size = Gen2::new(trimmed, 0.0).switch(self.dirs); - self.boxes.push((BoxLayout::new(size.to_size()), Gen2::default())); - } - - fn finish(mut self) -> BoxLayout { - let dirs = self.dirs; - let main = dirs.main.axis(); - - if self.expand.horizontal { - self.used.width = self.full_size.width; - } - - if self.expand.vertical { - self.used.height = self.full_size.height; - } - - let mut sum = 0.0; - let mut sums = Vec::with_capacity(self.boxes.len() + 1); - - for (boxed, _) in &self.boxes { - sums.push(sum); - sum += boxed.size.get(main); - } - - sums.push(sum); - - let mut layout = BoxLayout::new(self.used); - let used = self.used.switch(dirs); - - for (i, (boxed, aligns)) in self.boxes.into_iter().enumerate() { - let size = boxed.size.switch(dirs); - - let before = sums[i]; - let after = sum - sums[i + 1]; - let main_len = used.main - size.main; - let main_range = if dirs.main.is_positive() { - before .. main_len - after - } else { - main_len - before .. after - }; - - let cross_len = used.cross - size.cross; - let cross_range = if dirs.cross.is_positive() { - 0.0 .. cross_len - } else { - cross_len .. 0.0 - }; - - let main = aligns.main.apply(main_range); - let cross = aligns.cross.apply(cross_range); - let pos = Gen2::new(main, cross).switch(dirs).to_point(); - - layout.push_layout(pos, boxed); - } - - layout - } -} - -impl From<Stack> for LayoutNode { - fn from(stack: Stack) -> Self { - Self::dynamic(stack) - } -} |