From f22f9513aea21408ebf6febd01912e630e9ad5e6 Mon Sep 17 00:00:00 2001
From: Laurenz <laurmaedje@gmail.com>
Date: Thu, 17 Oct 2019 10:12:34 +0200
Subject: =?UTF-8?q?Add=20pagebreak=20function=20=E2=8F=AD?=
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---
 src/layout/flex.rs    |  4 +++-
 src/layout/stacked.rs |  1 +
 src/layout/tree.rs    | 18 +++++++++++++++---
 3 files changed, 19 insertions(+), 4 deletions(-)

(limited to 'src/layout')

diff --git a/src/layout/flex.rs b/src/layout/flex.rs
index 98cca2f9..39c16aef 100644
--- a/src/layout/flex.rs
+++ b/src/layout/flex.rs
@@ -17,6 +17,7 @@ use super::*;
 /// flows into a new line. A _glue_ layout is typically used for a space character
 /// since it prevents a space from appearing in the beginning or end of a line.
 /// However, it can be any layout.
+#[derive(Debug, Clone)]
 pub struct FlexLayouter {
     ctx: FlexContext,
     units: Vec<FlexUnit>,
@@ -64,6 +65,7 @@ impl FlexContext {
     }
 }
 
+#[derive(Debug, Clone)]
 enum FlexUnit {
     /// A content unit to be arranged flexibly.
     Boxed(Layout),
@@ -73,6 +75,7 @@ enum FlexUnit {
     Glue(Size2D),
 }
 
+#[derive(Debug, Clone)]
 struct FlexRun {
     content: Vec<(Size, Layout)>,
     size: Size2D,
@@ -168,7 +171,6 @@ impl FlexLayouter {
     }
 
     fn layout_glue(&mut self, glue: Size2D) {
-        self.flush_glue();
         self.cached_glue = Some(glue);
     }
 
diff --git a/src/layout/stacked.rs b/src/layout/stacked.rs
index 0b7bfd4f..d87e5394 100644
--- a/src/layout/stacked.rs
+++ b/src/layout/stacked.rs
@@ -3,6 +3,7 @@ use super::*;
 /// Layouts boxes stack-like.
 ///
 /// The boxes are arranged vertically, each layout gettings it's own "line".
+#[derive(Debug, Clone)]
 pub struct StackLayouter {
     ctx: StackContext,
     layouts: MultiLayout,
diff --git a/src/layout/tree.rs b/src/layout/tree.rs
index d125bc84..bd4adb8a 100644
--- a/src/layout/tree.rs
+++ b/src/layout/tree.rs
@@ -7,6 +7,7 @@ pub fn layout_tree(tree: &SyntaxTree, ctx: LayoutContext) -> LayoutResult<MultiL
     layouter.finish()
 }
 
+#[derive(Debug, Clone)]
 struct TreeLayouter<'a, 'p> {
     ctx: LayoutContext<'a, 'p>,
     stack: StackLayouter,
@@ -85,13 +86,18 @@ impl<'a, 'p> TreeLayouter<'a, 'p> {
 
     /// Layout a function.
     fn layout_func(&mut self, func: &FuncCall) -> LayoutResult<()> {
+        // Finish the current flex layout on a copy to find out how
+        // much space would be remaining if we finished.
+        let mut lookahead_stack = self.stack.clone();
+        let layouts = self.flex.clone().finish()?;
+        lookahead_stack.add_many(layouts)?;
+        let remaining = lookahead_stack.remaining();
+
         let mut ctx = self.ctx;
         ctx.style = &self.style;
         ctx.shrink_to_fit = true;
-
-        ctx.space.dimensions = self.stack.remaining();
+        ctx.space.dimensions = remaining;
         ctx.space.padding = SizeBox::zero();
-
         if let Some(space) = ctx.followup_spaces.as_mut() {
             *space = space.usable_space();
         }
@@ -127,6 +133,12 @@ impl<'a, 'p> TreeLayouter<'a, 'p> {
                 Command::SetStyle(style) => {
                     *self.style.to_mut() = style;
                 }
+
+                Command::FinishLayout => {
+                    self.finish_flex()?;
+                    self.stack.finish_layout(true)?;
+                    self.start_new_flex();
+                }
             }
         }
 
-- 
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