1 files changed, 20 insertions, 13 deletions

diff --git a/lua-bindings/diaphragm.lua b/lua-bindings/diaphragm.lua
index ad8aac6..57f065f 100644
--- a/lua-bindings/diaphragm.lua
+++ b/lua-bindings/diaphragm.lua
@@ -173,19 +173,9 @@ function M.rectangle.new(params)
 end
 
 function M.rectangle.surrounding(content, params)
-        params = params or {}
-        local margin = params.margin or 0
-        local margin_left = params.margin_left or margin
-        local margin_right = params.margin_right or margin
-        local margin_top = params.margin_top or margin
-        local margin_bottom = params.margin_bottom or margin
-
-        return M.rectangle.new(M.util.tbl_extend({
-                left = content.left - margin_left,
-                right = content.right + margin_right,
-                top = content.top - margin_top,
-                bottom = content.bottom + margin_bottom,
-        }, params))
+        local result = M.rectangle.new(params)
+        M.constraint.inset(content, result, params)
+        return result
 end
 
 M.straight_path = {}
@@ -270,6 +260,8 @@ end
 
 -- TODO: factor with vstack
 -- TODO: also as just a set of constraints
+-- TODO: add support for "growing" element height (or elements have same size)
+-- TODO: add orientation (ltr or rtl)
 function M.layout.hstack(params)
         local result = M.shape(params)
 
@@ -398,6 +390,21 @@ function M.constraint.same_width(elems)
         end
 end
 
+-- TODO: factor with rectangle surrounding
+function M.constraint.inset(child, parent, params)
+        params = params or {}
+        local margin = params.margin or 0
+        local margin_left = params.margin_left or margin
+        local margin_right = params.margin_right or margin
+        local margin_top = params.margin_top or margin
+        local margin_bottom = params.margin_bottom or margin
+
+        M.constrain(parent.left:eq(child.left - margin_left))
+        M.constrain(parent.right:eq(child.right + margin_right))
+        M.constrain(parent.top:eq(child.top - margin_top))
+        M.constrain(parent.bottom:eq(child.bottom + margin_bottom))
+end
+
 M.constrain = M.core.constrain
 M.draw = function(params)
         M.core.draw(M.util.tbl_extend(params, {