fixes for the absolute positioning bug

FlexLove.lua

@@ -1083,7 +1083,7 @@ end
 --- If called before FlexLove.init(), the element creation will be automatically queued and executed after initialization
 ---@param props ElementProps
 ---@param callback? function Optional callback function(element) that will be called with the created element (useful when queued)
----@return Element|nil element Returns element if initialized, nil if queued for later creation
+---@return Element -- Returns element if initialized, nil if queued for later creation
 function flexlove.new(props, callback)
   props = props or {}
 
@@ -1102,8 +1102,7 @@ function flexlove.new(props, callback)
         )
       end
     end
-
+    return nil
-    return nil -- Element will be created later
   end
 
   -- Determine effective mode: props.mode takes precedence over global mode

flexlove-0.7.1-1.rockspec

@@ -1,85 +0,0 @@
-package = "flexlove"
-version = "0.7.1-1"
-
-source = {
-  url = "git+https://github.com/mikefreno/FlexLove.git",
-  tag = "v0.7.1",
-}
-
-description = {
-  summary = "A comprehensive UI library providing flexbox/grid layouts, theming, animations, and event handling for LÖVE2D games",
-  detailed = [[
-      FlexLöve is a lightweight, flexible GUI library for LÖVE2D that implements a
-      flexbox-based layout system. The goals of this project are two-fold: first,
-      anyone with basic CSS knowledge should be able to use this library with minimal
-      learning curve. Second, this library should take you from early prototyping to
-      production.
-
-      Features:
-      - Flexbox and Grid Layout systems
-      - Modern theming with 9-patch support
-      - Animations and transitions
-      - Image rendering with CSS-like object-fit
-      - Touch events and gesture recognition
-      - Text input with rich editing features
-      - Responsive design with viewport units
-      - Both immediate and retained rendering modes
-
-      Going this route, you will need to link the luarocks path to your project:
-      (for mac/linux)
-      ```lua
-      package.path = package.path .. ";/Users/<username>/.luarocks/share/lua/<version>/?.lua"
-      package.path = package.path .. ";/Users/<username>/.luarocks/share/lua/<version>/?/init.lua"
-      package.cpath = package.cpath .. ";/Users/<username>/.luarocks/lib/lua/<version>/?.so"
-      ```
-   ]],
-  homepage = "https://mikefreno.github.io/FlexLove/",
-  license = "MIT",
-  maintainer = "Mike Freno",
-}
-
-dependencies = {
-  "lua >= 5.1",
-  "luautf8 >= 0.1.3",
-}
-
-build = {
-  type = "builtin",
-  modules = {
-    ["FlexLove"] = "FlexLove.lua",
-    ["FlexLove.modules.Animation"] = "modules/Animation.lua",
-    ["FlexLove.modules.Blur"] = "modules/Blur.lua",
-    ["FlexLove.modules.Calc"] = "modules/Calc.lua",
-    ["FlexLove.modules.Color"] = "modules/Color.lua",
-    ["FlexLove.modules.Context"] = "modules/Context.lua",
-    ["FlexLove.modules.Element"] = "modules/Element.lua",
-    ["FlexLove.modules.ErrorHandler"] = "modules/ErrorHandler.lua",
-    ["FlexLove.modules.EventHandler"] = "modules/EventHandler.lua",
-    ["FlexLove.modules.FFI"] = "modules/FFI.lua",
-    ["FlexLove.modules.GestureRecognizer"] = "modules/GestureRecognizer.lua",
-    ["FlexLove.modules.Grid"] = "modules/Grid.lua",
-    ["FlexLove.modules.ImageCache"] = "modules/ImageCache.lua",
-    ["FlexLove.modules.ImageRenderer"] = "modules/ImageRenderer.lua",
-    ["FlexLove.modules.ImageScaler"] = "modules/ImageScaler.lua",
-    ["FlexLove.modules.InputEvent"] = "modules/InputEvent.lua",
-    ["FlexLove.modules.LayoutEngine"] = "modules/LayoutEngine.lua",
-    ["FlexLove.modules.MemoryScanner"] = "modules/MemoryScanner.lua",
-    ["FlexLove.modules.ModuleLoader"] = "modules/ModuleLoader.lua",
-    ["FlexLove.modules.NinePatch"] = "modules/NinePatch.lua",
-    ["FlexLove.modules.Performance"] = "modules/Performance.lua",
-    ["FlexLove.modules.Renderer"] = "modules/Renderer.lua",
-    ["FlexLove.modules.RoundedRect"] = "modules/RoundedRect.lua",
-    ["FlexLove.modules.ScrollManager"] = "modules/ScrollManager.lua",
-    ["FlexLove.modules.StateManager"] = "modules/StateManager.lua",
-    ["FlexLove.modules.TextEditor"] = "modules/TextEditor.lua",
-    ["FlexLove.modules.Theme"] = "modules/Theme.lua",
-    ["FlexLove.modules.types"] = "modules/types.lua",
-    ["FlexLove.modules.Units"] = "modules/Units.lua",
-    ["FlexLove.modules.UTF8"] = "modules/UTF8.lua",
-    ["FlexLove.modules.utils"] = "modules/utils.lua",
-  },
-  --copy_directories = {
-  --"docs",
-  --"examples",
-  --},
-}

modules/Element.lua

@@ -1308,6 +1308,91 @@ function Element.new(props)
       self._originalPositioning = nil -- No explicit positioning
       self._explicitlyAbsolute = false
     end
+
+    -- Handle positioning properties for elements without parent
+    -- Handle top positioning with units
+    if props.top then
+      local isCalc = Element._Calc and Element._Calc.isCalc(props.top)
+      if type(props.top) == "string" or isCalc then
+        local value, unit = Element._Units.parse(props.top)
+        self.units.top = { value = value, unit = unit }
+        local resolvedTop = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportHeight)
+        if type(resolvedTop) ~= "number" then
+          Element._ErrorHandler:warn("Element", "LAY_003", {
+            issue = "top resolution returned non-number value",
+            type = type(resolvedTop),
+          })
+          resolvedTop = 0
+        end
+        self.top = resolvedTop
+      else
+        self.top = props.top
+        self.units.top = { value = props.top, unit = "px" }
+      end
+    end
+
+    -- Handle right positioning with units
+    if props.right then
+      local isCalc = Element._Calc and Element._Calc.isCalc(props.right)
+      if type(props.right) == "string" or isCalc then
+        local value, unit = Element._Units.parse(props.right)
+        self.units.right = { value = value, unit = unit }
+        local resolvedRight = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportWidth)
+        if type(resolvedRight) ~= "number" then
+          Element._ErrorHandler:warn("Element", "LAY_003", {
+            issue = "right resolution returned non-number value",
+            type = type(resolvedRight),
+          })
+          resolvedRight = 0
+        end
+        self.right = resolvedRight
+      else
+        self.right = props.right
+        self.units.right = { value = props.right, unit = "px" }
+      end
+    end
+
+    -- Handle bottom positioning with units
+    if props.bottom then
+      local isCalc = Element._Calc and Element._Calc.isCalc(props.bottom)
+      if type(props.bottom) == "string" or isCalc then
+        local value, unit = Element._Units.parse(props.bottom)
+        self.units.bottom = { value = value, unit = unit }
+        local resolvedBottom = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportHeight)
+        if type(resolvedBottom) ~= "number" then
+          Element._ErrorHandler:warn("Element", "LAY_003", {
+            issue = "bottom resolution returned non-number value",
+            type = type(resolvedBottom),
+          })
+          resolvedBottom = 0
+        end
+        self.bottom = resolvedBottom
+      else
+        self.bottom = props.bottom
+        self.units.bottom = { value = props.bottom, unit = "px" }
+      end
+    end
+
+    -- Handle left positioning with units
+    if props.left then
+      local isCalc = Element._Calc and Element._Calc.isCalc(props.left)
+      if type(props.left) == "string" or isCalc then
+        local value, unit = Element._Units.parse(props.left)
+        self.units.left = { value = value, unit = unit }
+        local resolvedLeft = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportWidth)
+        if type(resolvedLeft) ~= "number" then
+          Element._ErrorHandler:warn("Element", "LAY_003", {
+            issue = "left resolution returned non-number value",
+            type = type(resolvedLeft),
+          })
+          resolvedLeft = 0
+        end
+        self.left = resolvedLeft
+      else
+        self.left = props.left
+        self.units.left = { value = props.left, unit = "px" }
+      end
+    end
   else
     -- Set positioning first and track if explicitly set
     self._originalPositioning = props.positioning -- Track original intent
@@ -1468,106 +1553,94 @@ function Element.new(props)
       end
     end
 
+    -- Handle positioning properties BEFORE adding to parent (so they're available during layout)
+    -- Handle top positioning with units
+    if props.top then
+      local isCalc = Element._Calc and Element._Calc.isCalc(props.top)
+      if type(props.top) == "string" or isCalc then
+        local value, unit = Element._Units.parse(props.top)
+        self.units.top = { value = value, unit = unit }
+        local resolvedTop = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportHeight)
+        if type(resolvedTop) ~= "number" then
+          Element._ErrorHandler:warn("Element", "LAY_003", {
+            issue = "top resolution returned non-number value",
+            type = type(resolvedTop),
+          })
+          resolvedTop = 0
+        end
+        self.top = resolvedTop
+      else
+        self.top = props.top
+        self.units.top = { value = props.top, unit = "px" }
+      end
+    end
+
+    -- Handle right positioning with units
+    if props.right then
+      local isCalc = Element._Calc and Element._Calc.isCalc(props.right)
+      if type(props.right) == "string" or isCalc then
+        local value, unit = Element._Units.parse(props.right)
+        self.units.right = { value = value, unit = unit }
+        local resolvedRight = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportWidth)
+        if type(resolvedRight) ~= "number" then
+          Element._ErrorHandler:warn("Element", "LAY_003", {
+            issue = "right resolution returned non-number value",
+            type = type(resolvedRight),
+          })
+          resolvedRight = 0
+        end
+        self.right = resolvedRight
+      else
+        self.right = props.right
+        self.units.right = { value = props.right, unit = "px" }
+      end
+    end
+
+    -- Handle bottom positioning with units
+    if props.bottom then
+      local isCalc = Element._Calc and Element._Calc.isCalc(props.bottom)
+      if type(props.bottom) == "string" or isCalc then
+        local value, unit = Element._Units.parse(props.bottom)
+        self.units.bottom = { value = value, unit = unit }
+        local resolvedBottom = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportHeight)
+        if type(resolvedBottom) ~= "number" then
+          Element._ErrorHandler:warn("Element", "LAY_003", {
+            issue = "bottom resolution returned non-number value",
+            type = type(resolvedBottom),
+          })
+          resolvedBottom = 0
+        end
+        self.bottom = resolvedBottom
+      else
+        self.bottom = props.bottom
+        self.units.bottom = { value = props.bottom, unit = "px" }
+      end
+    end
+
+    -- Handle left positioning with units
+    if props.left then
+      local isCalc = Element._Calc and Element._Calc.isCalc(props.left)
+      if type(props.left) == "string" or isCalc then
+        local value, unit = Element._Units.parse(props.left)
+        self.units.left = { value = value, unit = unit }
+        local resolvedLeft = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportWidth)
+        if type(resolvedLeft) ~= "number" then
+          Element._ErrorHandler:warn("Element", "LAY_003", {
+            issue = "left resolution returned non-number value",
+            type = type(resolvedLeft),
+          })
+          resolvedLeft = 0
+        end
+        self.left = resolvedLeft
+      else
+        self.left = props.left
+        self.units.left = { value = props.left, unit = "px" }
+      end
+    end
+
     props.parent:addChild(self)
   end
 
-  -- Handle positioning properties for ALL elements (with or without parent)
-  -- Handle top positioning with units
-  if props.top then
-    local isCalc = Element._Calc and Element._Calc.isCalc(props.top)
-    if type(props.top) == "string" or isCalc then
-      local value, unit = Element._Units.parse(props.top)
-      self.units.top = { value = value, unit = unit }
-      local resolvedTop = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportHeight)
-      if type(resolvedTop) ~= "number" then
-        Element._ErrorHandler:warn("Element", "LAY_003", {
-          issue = "top resolution returned non-number value",
-          type = type(resolvedTop),
-        })
-        resolvedTop = 0
-      end
-      self.top = resolvedTop
-    else
-      self.top = props.top
-      self.units.top = { value = props.top, unit = "px" }
-    end
-  else
-    self.top = nil
-    self.units.top = nil
-  end
-
-  -- Handle right positioning with units
-  if props.right then
-    local isCalc = Element._Calc and Element._Calc.isCalc(props.right)
-    if type(props.right) == "string" or isCalc then
-      local value, unit = Element._Units.parse(props.right)
-      self.units.right = { value = value, unit = unit }
-      local resolvedRight = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportWidth)
-      if type(resolvedRight) ~= "number" then
-        Element._ErrorHandler:warn("Element", "LAY_003", {
-          issue = "right resolution returned non-number value",
-          type = type(resolvedRight),
-        })
-        resolvedRight = 0
-      end
-      self.right = resolvedRight
-    else
-      self.right = props.right
-      self.units.right = { value = props.right, unit = "px" }
-    end
-  else
-    self.right = nil
-    self.units.right = nil
-  end
-
-  -- Handle bottom positioning with units
-  if props.bottom then
-    local isCalc = Element._Calc and Element._Calc.isCalc(props.bottom)
-    if type(props.bottom) == "string" or isCalc then
-      local value, unit = Element._Units.parse(props.bottom)
-      self.units.bottom = { value = value, unit = unit }
-      local resolvedBottom = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportHeight)
-      if type(resolvedBottom) ~= "number" then
-        Element._ErrorHandler:warn("Element", "LAY_003", {
-          issue = "bottom resolution returned non-number value",
-          type = type(resolvedBottom),
-        })
-        resolvedBottom = 0
-      end
-      self.bottom = resolvedBottom
-    else
-      self.bottom = props.bottom
-      self.units.bottom = { value = props.bottom, unit = "px" }
-    end
-  else
-    self.bottom = nil
-    self.units.bottom = nil
-  end
-
-  -- Handle left positioning with units
-  if props.left then
-    local isCalc = Element._Calc and Element._Calc.isCalc(props.left)
-    if type(props.left) == "string" or isCalc then
-      local value, unit = Element._Units.parse(props.left)
-      self.units.left = { value = value, unit = unit }
-      local resolvedLeft = Element._Units.resolve(value, unit, viewportWidth, viewportHeight, viewportWidth)
-      if type(resolvedLeft) ~= "number" then
-        Element._ErrorHandler:warn("Element", "LAY_003", {
-          issue = "left resolution returned non-number value",
-          type = type(resolvedLeft),
-        })
-        resolvedLeft = 0
-      end
-      self.left = resolvedLeft
-    else
-      self.left = props.left
-      self.units.left = { value = props.left, unit = "px" }
-    end
-  else
-    self.left = nil
-    self.units.left = nil
-  end
-
   if self.positioning == Element._utils.enums.Positioning.FLEX then
     -- Validate enum properties
     if props.flexDirection then
@@ -2135,6 +2208,9 @@ function Element:addChild(child)
 
   table.insert(self.children, child)
 
+  -- Mark parent as having dirty children to trigger layout recalculation
+  self._childrenDirty = true
+
   -- Only recalculate auto-sizing if the child participates in layout
   -- (CSS: absolutely positioned children don't affect parent auto-sizing)
   if not child._explicitlyAbsolute then

modules/LayoutEngine.lua

@@ -123,6 +123,8 @@ end
 --- Apply CSS positioning offsets (top, right, bottom, left) to a child element
 ---@param child Element The element to apply offsets to
 function LayoutEngine:applyPositioningOffsets(child)
+
+  
   if not child then
     return
   end
@@ -139,7 +141,7 @@ function LayoutEngine:applyPositioningOffsets(child)
     or child.positioning == self._Positioning.GRID
     or (child.positioning == self._Positioning.ABSOLUTE and not child._explicitlyAbsolute)
 
-  if not isFlexChild then
+  if not isFlexChild and child._explicitlyAbsolute then
     -- Apply absolute positioning for explicitly absolute children
     -- Apply top offset (distance from parent's content box top edge)
     if child.top then
@@ -224,6 +226,7 @@ end
 
 --- Layout children within this element according to positioning mode
 function LayoutEngine:layoutChildren()
+  
   -- Start performance timing first (before any early returns)
   local timerName = nil
   if LayoutEngine._Performance and LayoutEngine._Performance.enabled and self.element then
@@ -250,9 +253,23 @@ function LayoutEngine:layoutChildren()
   if self.positioning == self._Positioning.ABSOLUTE or self.positioning == self._Positioning.RELATIVE then
     -- Absolute/Relative positioned containers don't layout their children according to flex rules,
     -- but they should still apply CSS positioning offsets to their children
+    local baseX = (self.element.x or 0) + self.element.padding.left
+    local baseY = (self.element.y or 0) + self.element.padding.top
+    
     for _, child in ipairs(self.element.children) do
+      -- Apply CSS positioning offsets to children with absolute positioning
       if child.top or child.right or child.bottom or child.left then
         self:applyPositioningOffsets(child)
+      elseif child.positioning == self._Positioning.RELATIVE then
+        -- Reposition relative children to match parent's new position
+        -- This is needed when the parent (absolute container) moves after children are created
+        child.x = baseX
+        child.y = baseY
+        
+        -- If child has children, recursively layout them
+        if #child.children > 0 then
+          child:layoutChildren()
+        end
       end
     end
 
@@ -316,81 +333,45 @@ function LayoutEngine:layoutChildren()
     end
   end
 
+  -- CSS-compliant behavior: absolutely positioned elements are completely removed from normal flow
+  -- They do NOT reserve space or affect flex layout calculations at all
+  
+  -- If no flex children, skip flex layout but still position absolute children
   if #flexChildren == 0 then
-    return
+    -- Position absolutely positioned children even when there are no flex children
-  end
+    for i, child in ipairs(self.element.children) do
-
+      if child.positioning == self._Positioning.ABSOLUTE and child._explicitlyAbsolute then
-  -- Calculate space reserved by absolutely positioned siblings with explicit positioning
+        self:applyPositioningOffsets(child)
-  local reservedMainStart = 0 -- Space reserved at the start of main axis (left for horizontal, top for vertical)
+        
-  local reservedMainEnd = 0 -- Space reserved at the end of main axis (right for horizontal, bottom for vertical)
+        -- If child has children, layout them after position change
-  local reservedCrossStart = 0 -- Space reserved at the start of cross axis (top for horizontal, left for vertical)
+        if #child.children > 0 then
-  local reservedCrossEnd = 0 -- Space reserved at the end of cross axis (bottom for horizontal, right for vertical)
+          child:layoutChildren()
-
-  for _, child in ipairs(self.element.children) do
-    -- Only consider absolutely positioned children with explicit positioning
-    if child.positioning == self._Positioning.ABSOLUTE and child._explicitlyAbsolute then
-      -- BORDER-BOX MODEL: Use border-box dimensions for space calculations
-      local childBorderBoxWidth = child:getBorderBoxWidth()
-      local childBorderBoxHeight = child:getBorderBoxHeight()
-
-      if self.flexDirection == self._FlexDirection.HORIZONTAL then
-        -- Horizontal layout: main axis is X, cross axis is Y
-        -- Check for left positioning (reserves space at main axis start)
-        if child.left then
-          local spaceNeeded = child.left + childBorderBoxWidth
-          reservedMainStart = math.max(reservedMainStart, spaceNeeded)
-        end
-        -- Check for right positioning (reserves space at main axis end)
-        if child.right then
-          local spaceNeeded = child.right + childBorderBoxWidth
-          reservedMainEnd = math.max(reservedMainEnd, spaceNeeded)
-        end
-        -- Check for top positioning (reserves space at cross axis start)
-        if child.top then
-          local spaceNeeded = child.top + childBorderBoxHeight
-          reservedCrossStart = math.max(reservedCrossStart, spaceNeeded)
-        end
-        -- Check for bottom positioning (reserves space at cross axis end)
-        if child.bottom then
-          local spaceNeeded = child.bottom + childBorderBoxHeight
-          reservedCrossEnd = math.max(reservedCrossEnd, spaceNeeded)
-        end
-      else
-        -- Vertical layout: main axis is Y, cross axis is X
-        -- Check for top positioning (reserves space at main axis start)
-        if child.top then
-          local spaceNeeded = child.top + childBorderBoxHeight
-          reservedMainStart = math.max(reservedMainStart, spaceNeeded)
-        end
-        -- Check for bottom positioning (reserves space at main axis end)
-        if child.bottom then
-          local spaceNeeded = child.bottom + childBorderBoxHeight
-          reservedMainEnd = math.max(reservedMainEnd, spaceNeeded)
-        end
-        -- Check for left positioning (reserves space at cross axis start)
-        if child.left then
-          local spaceNeeded = child.left + childBorderBoxWidth
-          reservedCrossStart = math.max(reservedCrossStart, spaceNeeded)
-        end
-        -- Check for right positioning (reserves space at cross axis end)
-        if child.right then
-          local spaceNeeded = child.right + childBorderBoxWidth
-          reservedCrossEnd = math.max(reservedCrossEnd, spaceNeeded)
         end
       end
     end
+    
+    -- Detect overflow after children positioning
+    if self.element._detectOverflow then
+      self.element:_detectOverflow()
+    end
+    
+    -- Stop performance timing
+    if timerName and LayoutEngine._Performance then
+      LayoutEngine._Performance:stopTimer(timerName)
+    end
+    return
   end
-
+  
-  -- Calculate available space (accounting for padding and reserved space)
+  -- Calculate available space (accounting for padding only, NOT absolute children)
   -- BORDER-BOX MODEL: element.width and element.height are already content dimensions (padding subtracted)
   local availableMainSize = 0
   local availableCrossSize = 0
   if self.flexDirection == self._FlexDirection.HORIZONTAL then
-    availableMainSize = self.element.width - reservedMainStart - reservedMainEnd
+    availableMainSize = self.element.width
-    availableCrossSize = self.element.height - reservedCrossStart - reservedCrossEnd
+    availableCrossSize = self.element.height
   else
-    availableMainSize = self.element.height - reservedMainStart - reservedMainEnd
+    availableMainSize = self.element.height
-    availableCrossSize = self.element.width - reservedCrossStart - reservedCrossEnd
+    availableCrossSize = self.element.width
   end
 
   -- Handle flex wrap: create lines of children
@@ -614,9 +595,9 @@ function LayoutEngine:layoutChildren()
       if self.flexDirection == self._FlexDirection.HORIZONTAL then
         -- Horizontal layout: main axis is X, cross axis is Y
         -- Position child at border box (x, y represents top-left including padding)
-        -- Add reservedMainStart and left margin to account for absolutely positioned siblings and margins
+        -- CSS-compliant: absolute children don't affect flex positioning, so no reserved space offset
         local childMarginLeft = childMargin.left
-        child.x = elementX + elementPaddingLeft + reservedMainStart + currentMainPos + childMarginLeft
+        child.x = elementX + elementPaddingLeft + currentMainPos + childMarginLeft
 
         -- BORDER-BOX MODEL: Use border-box dimensions for alignment calculations
         local childBorderBoxHeight = child:getBorderBoxHeight()
@@ -625,16 +606,15 @@ function LayoutEngine:layoutChildren()
         local childTotalCrossSize = childBorderBoxHeight + childMarginTop + childMarginBottom
 
         if effectiveAlign == alignItems_FLEX_START then
-          child.y = elementY + elementPaddingTop + reservedCrossStart + currentCrossPos + childMarginTop
+          child.y = elementY + elementPaddingTop + currentCrossPos + childMarginTop
         elseif effectiveAlign == alignItems_CENTER then
           child.y = elementY
             + elementPaddingTop
-            + reservedCrossStart
             + currentCrossPos
             + ((lineHeight - childTotalCrossSize) / 2)
             + childMarginTop
         elseif effectiveAlign == alignItems_FLEX_END then
-          child.y = elementY + elementPaddingTop + reservedCrossStart + currentCrossPos + lineHeight - childTotalCrossSize + childMarginTop
+          child.y = elementY + elementPaddingTop + currentCrossPos + lineHeight - childTotalCrossSize + childMarginTop
         elseif effectiveAlign == alignItems_STRETCH then
           -- STRETCH: Only apply if height was not explicitly set
           if childAutosizing and childAutosizing.height then
@@ -643,7 +623,7 @@ function LayoutEngine:layoutChildren()
             child._borderBoxHeight = availableHeight
             child.height = math.max(0, availableHeight - childPadding.top - childPadding.bottom)
           end
-          child.y = elementY + elementPaddingTop + reservedCrossStart + currentCrossPos + childMarginTop
+          child.y = elementY + elementPaddingTop + currentCrossPos + childMarginTop
         end
 
         -- Apply positioning offsets (top, right, bottom, left)
@@ -659,9 +639,9 @@ function LayoutEngine:layoutChildren()
       else
         -- Vertical layout: main axis is Y, cross axis is X
         -- Position child at border box (x, y represents top-left including padding)
-        -- Add reservedMainStart and top margin to account for absolutely positioned siblings and margins
+        -- CSS-compliant: absolute children don't affect flex positioning, so no reserved space offset
         local childMarginTop = childMargin.top
-        child.y = elementY + elementPaddingTop + reservedMainStart + currentMainPos + childMarginTop
+        child.y = elementY + elementPaddingTop + currentMainPos + childMarginTop
 
         -- BORDER-BOX MODEL: Use border-box dimensions for alignment calculations
         local childBorderBoxWidth = child:getBorderBoxWidth()
@@ -671,16 +651,15 @@ function LayoutEngine:layoutChildren()
         local elementPaddingLeft = elementPadding.left
 
         if effectiveAlign == alignItems_FLEX_START then
-          child.x = elementX + elementPaddingLeft + reservedCrossStart + currentCrossPos + childMarginLeft
+          child.x = elementX + elementPaddingLeft + currentCrossPos + childMarginLeft
         elseif effectiveAlign == alignItems_CENTER then
           child.x = elementX
             + elementPaddingLeft
-            + reservedCrossStart
             + currentCrossPos
             + ((lineHeight - childTotalCrossSize) / 2)
             + childMarginLeft
         elseif effectiveAlign == alignItems_FLEX_END then
-          child.x = elementX + elementPaddingLeft + reservedCrossStart + currentCrossPos + lineHeight - childTotalCrossSize + childMarginLeft
+          child.x = elementX + elementPaddingLeft + currentCrossPos + lineHeight - childTotalCrossSize + childMarginLeft
         elseif effectiveAlign == alignItems_STRETCH then
           -- STRETCH: Only apply if width was not explicitly set
           if childAutosizing and childAutosizing.width then
@@ -689,7 +668,7 @@ function LayoutEngine:layoutChildren()
             child._borderBoxWidth = availableWidth
             child.width = math.max(0, availableWidth - childPadding.left - childPadding.right)
           end
-          child.x = elementX + elementPaddingLeft + reservedCrossStart + currentCrossPos + childMarginLeft
+          child.x = elementX + elementPaddingLeft + currentCrossPos + childMarginLeft
         end
 
         -- Apply positioning offsets (top, right, bottom, left)
@@ -710,7 +689,7 @@ function LayoutEngine:layoutChildren()
   end
 
   -- Position explicitly absolute children after flex layout
-  for _, child in ipairs(self.element.children) do
+  for i, child in ipairs(self.element.children) do
     if child.positioning == self._Positioning.ABSOLUTE and child._explicitlyAbsolute then
       -- Apply positioning offsets (top, right, bottom, left)
       self:applyPositioningOffsets(child)

testing/__tests__/absolute_positioning_test.lua

@@ -0,0 +1,267 @@
+package.path = package.path .. ";./?.lua;./modules/?.lua"
+local originalSearchers = package.searchers or package.loaders
+table.insert(originalSearchers, 2, function(modname)
+  if modname:match("^FlexLove%.modules%.") then
+    local moduleName = modname:gsub("^FlexLove%.modules%.", "")
+    return function()
+      return require("modules." .. moduleName)
+    end
+  end
+end)
+require("testing.loveStub")
+local luaunit = require("testing.luaunit")
+
+-- Load FlexLove
+local FlexLove = require("FlexLove")
+
+TestAbsolutePositioning = {}
+
+function TestAbsolutePositioning:setUp()
+  FlexLove.init()
+end
+
+function TestAbsolutePositioning:testAbsoluteBottomRightInFlexParent()
+  -- Create a flex parent
+  local parent = FlexLove.new({
+    positioning = "flex",
+    width = 400,
+    height = 400,
+  })
+
+  -- Create an absolutely positioned child with bottom and right offsets
+  local child = FlexLove.new({
+    parent = parent,
+    positioning = "absolute",
+    bottom = 0,
+    right = 0,
+    width = 100,
+    height = 100,
+  })
+
+  -- Child should be positioned at bottom-right
+  luaunit.assertEquals(child.x, 300, "Child x should be 300 (400 - 100)")
+  luaunit.assertEquals(child.y, 300, "Child y should be 300 (400 - 100)")
+end
+
+function TestAbsolutePositioning:testAbsoluteTopLeftInFlexParent()
+  -- Create a flex parent
+  local parent = FlexLove.new({
+    positioning = "flex",
+    width = 400,
+    height = 400,
+  })
+
+  -- Create an absolutely positioned child with top and left offsets
+  local child = FlexLove.new({
+    parent = parent,
+    positioning = "absolute",
+    top = 10,
+    left = 10,
+    width = 100,
+    height = 100,
+  })
+
+  -- Child should be positioned at top-left with 10px offset
+  luaunit.assertEquals(child.x, 10, "Child x should be 10")
+  luaunit.assertEquals(child.y, 10, "Child y should be 10")
+end
+
+function TestAbsolutePositioning:testAbsoluteWithPaddingParent()
+  -- Create a flex parent with padding
+  local parent = FlexLove.new({
+    positioning = "flex",
+    width = 400,
+    height = 400,
+    padding = 20,
+  })
+
+  -- Create an absolutely positioned child
+  local child = FlexLove.new({
+    parent = parent,
+    positioning = "absolute",
+    bottom = 0,
+    right = 0,
+    width = 100,
+    height = 100,
+  })
+
+  -- Absolute positioning is relative to parent's padding box
+  -- Parent content box: 400 - 20 (left padding) - 20 (right padding) = 360
+  -- Child x: parent.x (0) + padding.left (20) + content.width (360) - right (0) - child.width (100) = 280
+  luaunit.assertEquals(child.x, 280, "Child x should account for parent padding")
+  luaunit.assertEquals(child.y, 280, "Child y should account for parent padding")
+end
+
+function TestAbsolutePositioning:testAbsoluteDoesNotAffectFlexLayout()
+  -- Create a flex parent
+  local parent = FlexLove.new({
+    positioning = "flex",
+    flexDirection = "horizontal",
+    width = 400,
+    height = 400,
+  })
+
+  -- Add flex children
+  local flexChild1 = FlexLove.new({
+    parent = parent,
+    width = 100,
+    height = 100,
+  })
+
+  local flexChild2 = FlexLove.new({
+    parent = parent,
+    width = 100,
+    height = 100,
+  })
+
+  -- Add absolutely positioned child
+  local absChild = FlexLove.new({
+    parent = parent,
+    positioning = "absolute",
+    top = 0,
+    left = 0,
+    width = 50,
+    height = 50,
+  })
+
+  -- Flex children should be positioned normally (absolute child doesn't affect layout)
+  luaunit.assertEquals(flexChild1.x, 0, "First flex child at x=0")
+  luaunit.assertEquals(flexChild2.x, 100, "Second flex child at x=100")
+
+  -- Absolute child should be at top-left
+  luaunit.assertEquals(absChild.x, 0, "Absolute child at x=0")
+  luaunit.assertEquals(absChild.y, 0, "Absolute child at y=0")
+end
+
+function TestAbsolutePositioning:testMultipleAbsoluteChildren()
+  -- Create a flex parent
+  local parent = FlexLove.new({
+    positioning = "flex",
+    width = 400,
+    height = 400,
+  })
+
+  -- Create multiple absolutely positioned children
+  local topLeft = FlexLove.new({
+    parent = parent,
+    positioning = "absolute",
+    top = 0,
+    left = 0,
+    width = 50,
+    height = 50,
+  })
+
+  local topRight = FlexLove.new({
+    parent = parent,
+    positioning = "absolute",
+    top = 0,
+    right = 0,
+    width = 50,
+    height = 50,
+  })
+
+  local bottomLeft = FlexLove.new({
+    parent = parent,
+    positioning = "absolute",
+    bottom = 0,
+    left = 0,
+    width = 50,
+    height = 50,
+  })
+
+  local bottomRight = FlexLove.new({
+    parent = parent,
+    positioning = "absolute",
+    bottom = 0,
+    right = 0,
+    width = 50,
+    height = 50,
+  })
+
+  -- Verify positions
+  luaunit.assertEquals(topLeft.x, 0, "Top-left x")
+  luaunit.assertEquals(topLeft.y, 0, "Top-left y")
+
+  luaunit.assertEquals(topRight.x, 350, "Top-right x")
+  luaunit.assertEquals(topRight.y, 0, "Top-right y")
+
+  luaunit.assertEquals(bottomLeft.x, 0, "Bottom-left x")
+  luaunit.assertEquals(bottomLeft.y, 350, "Bottom-left y")
+
+  luaunit.assertEquals(bottomRight.x, 350, "Bottom-right x")
+  luaunit.assertEquals(bottomRight.y, 350, "Bottom-right y")
+end
+
+function TestAbsolutePositioning:testAbsoluteInImmediateMode()
+  FlexLove.setMode("immediate")
+
+  local parent, child
+
+  local function createUI()
+    parent = FlexLove.new({
+      positioning = "flex",
+      width = 400,
+      height = 400,
+    })
+
+    child = FlexLove.new({
+      parent = parent,
+      positioning = "absolute",
+      bottom = 0,
+      right = 0,
+      width = 100,
+      height = 100,
+    })
+  end
+
+  -- First frame
+  FlexLove.beginFrame()
+  createUI()
+  FlexLove.endFrame()
+
+  luaunit.assertEquals(child.x, 300, "Frame 1: Child x should be 300")
+  luaunit.assertEquals(child.y, 300, "Frame 1: Child y should be 300")
+
+  -- Second frame (recreate UI)
+  FlexLove.beginFrame()
+  createUI()
+  FlexLove.endFrame()
+
+  luaunit.assertEquals(child.x, 300, "Frame 2: Child x should be 300")
+  luaunit.assertEquals(child.y, 300, "Frame 2: Child y should be 300")
+
+  FlexLove.setMode("retained")
+end
+
+function TestAbsolutePositioning:testExplicitlyAbsoluteFlagIsSet()
+  local parent = FlexLove.new({
+    positioning = "flex",
+    width = 400,
+    height = 400,
+  })
+
+  -- Child with explicit absolute positioning
+  local absoluteChild = FlexLove.new({
+    parent = parent,
+    positioning = "absolute",
+    width = 100,
+    height = 100,
+  })
+
+  -- Child without explicit positioning (participates in flex)
+  local flexChild = FlexLove.new({
+    parent = parent,
+    width = 100,
+    height = 100,
+  })
+
+  luaunit.assertEquals(absoluteChild._explicitlyAbsolute, true, "Explicitly absolute child should have _explicitlyAbsolute = true")
+  luaunit.assertEquals(absoluteChild._originalPositioning, "absolute", "Absolute child should have _originalPositioning = 'absolute'")
+
+  luaunit.assertEquals(flexChild._explicitlyAbsolute, false, "Flex child should have _explicitlyAbsolute = false")
+  luaunit.assertEquals(flexChild._originalPositioning, nil, "Flex child should have _originalPositioning = nil")
+end
+
+if not _G.RUNNING_ALL_TESTS then
+  os.exit(luaunit.LuaUnit.run())
+end

testing/runAll.lua

@@ -36,6 +36,7 @@ end
 local luaunit = require("testing.luaunit")
 
 local testFiles = {
+  "testing/__tests__/absolute_positioning_test.lua",
   "testing/__tests__/animation_test.lua",
   "testing/__tests__/blur_test.lua",
   "testing/__tests__/calc_test.lua",