layout/engine: fix double positioning absolute boxes

by checking if the box has been positioned before. Not a very
good solution, but it works...

2 files changed, 11 insertions, 0 deletions

diff --git a/src/layout/box.nim b/src/layout/box.nim
index c2b6a449..583e0d75 100644
--- a/src/layout/box.nim
+++ b/src/layout/box.nim
@@ -118,6 +118,9 @@ type
     viewport*: Viewport
     offset*: Offset
 
+    #TODO this should not be needed.
+    was_positioned*: bool
+
     # This is the padding width/height.
     width*: int
     height*: int
diff --git a/src/layout/engine.nim b/src/layout/engine.nim
index eebc7ef0..02e7398e 100644
--- a/src/layout/engine.nim
+++ b/src/layout/engine.nim
@@ -839,6 +839,12 @@ proc positionBlocks(box: BlockBox) =
   template defer_out_of_flow() =
     # Skip absolute, fixed, sticky
     while i < box.nested.len:
+      if box.nested[i].was_positioned: # already positioned, ignore.
+        #TODO: this is actually an ugly hack to avoid absolute boxes being
+        # positioned twice. A proper fix would be to appropriately place
+        # them in the tree *before* positioning (i.e. in buildBlock.)
+        inc i
+        continue
       case box.nested[i].computed{"position"}
       of POSITION_STATIC, POSITION_RELATIVE:
         break
@@ -916,6 +922,7 @@ proc positionBlocks(box: BlockBox) =
     child.offset.x += child.margin_left
     if box.computed{"position"} == POSITION_RELATIVE:
       box.positionRelative(child)
+    child.was_positioned = true #TODO see above
 
   box.height += box.padding_bottom
 
@@ -926,6 +933,7 @@ proc positionBlocks(box: BlockBox) =
   box.width += box.padding_right
 
   for child in deferred:
+    child.was_positioned = true #TODO see above
     case child.computed{"position"}
     of POSITION_ABSOLUTE:
       positionAbsolute(child)