Complete layout tree generation

1 files changed, 25 insertions, 14 deletions

diff --git a/src/layout.nim b/src/layout.nim
index cfec966..2be0610 100644
--- a/src/layout.nim
+++ b/src/layout.nim
@@ -8,6 +8,12 @@ import print
 # Note that Nim's UFCS means that typically calls to get() look like value.get(T()).
 # (T() is an object constructor, and [] are both openarray accesses and generic brackets)
 
+const
+  window_width = 500
+  window_height = 500
+  hstep = 13
+  vstep = 18
+
 # const inline_elements = []
 
 const block_elements = [
@@ -23,7 +29,7 @@ const block_elements = [
 # The Document layout is included because pages can
 # have multiple Documents through the use of iframes.
 type LayoutKind = enum
-  Inline, Block, Document
+  Document, Block, Inline
 
 # Improve error messages: suggest a ref object when failing from recursion
 type Layout = ref object
@@ -34,12 +40,13 @@ type Layout = ref object
   x, y, width, height: float
   cursorX, cursorY: float
   case kind: LayoutKind:
-    of Inline:
-      weight: int
-    of Block:
-      discard
     of Document:
       discard
+    of Block:
+      discard
+    of Inline:
+      cx, cy: float # cursor
+      weight: int
 
 # The layout tree is constructed in a two-part process:
 # 1. We iterate through the node tree to create a simple layout tree.
@@ -79,34 +86,38 @@ func get(self: Option[Layout]): auto =
 func calculate_position(self: Layout) =
   case self.kind:
   of Document:
-    self.x = 1
-    self.y = 1
-    self.width = 500
-    self.height = 500
-  of Inline:
+    self.width = window_width - 2*hstep
+    self.x = hstep
+    self.y = vstep
+  of Block:
     self.x = self.parent.get.x # every object starts at its parent's left edge...
     self.y = # if there is no previous sibiling, they start at their parent's top edge...
       if self.previous.isSome(): self.previous.get.y + self.previous.get.height
       else: self.parent.get.y
     self.width = self.parent.get.width # by default, objects are greedy and take up all the space they can get...
-  of Block:
+  of Inline:
     self.x = self.parent.get.x
     self.y =
       if self.previous.isSome(): self.previous.get.y + self.previous.get.height
       else: self.parent.get.y
     self.width = self.parent.get.width
+    self.cx = self.x
+    self.cy = self.y
 
   for child in self.children:
     calculate_position(child)
 
   case self.kind:
-  of Inline:
-    self.height = 0
+  of Document:
+    self.height =
+      if self.children.len != 0: self.children.map(x => x.height).foldl(a + b) + 2*vstep
+      else: 2*vstep
   of Block:
     self.height = # height calculation must come after the recursive call
       if self.children.len != 0: self.children.map(x => x.height).foldl(a + b)
       else: 0
-  else: discard # the Document layout doesn't matter
+  of Inline:
+    self.height = self.cy - self.y
 
 # These implicitly-mutating parameters are a bit gross, but
 # really seem like the best way to build this layout tree.