module refactor completion

flexlove/Grid.lua

@@ -0,0 +1,136 @@
+-- ====================
+-- Grid Layout System
+-- ====================
+
+local modulePath = (...):match("(.-)[^%.]+$")
+local utils = require(modulePath .. "utils")
+local enums = utils.enums
+
+local Positioning = enums.Positioning
+local AlignItems = enums.AlignItems
+
+--- Simple grid layout calculations
+local Grid = {}
+
+--- Layout grid items within a grid container using simple row/column counts
+---@param element Element -- Grid container element
+function Grid.layoutGridItems(element)
+  local rows = element.gridRows or 1
+  local columns = element.gridColumns or 1
+
+  -- Calculate space reserved by absolutely positioned siblings
+  local reservedLeft = 0
+  local reservedRight = 0
+  local reservedTop = 0
+  local reservedBottom = 0
+
+  for _, child in ipairs(element.children) do
+    -- Only consider absolutely positioned children with explicit positioning
+    if child.positioning == 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 child.left then
+        reservedLeft = math.max(reservedLeft, child.left + childBorderBoxWidth)
+      end
+      if child.right then
+        reservedRight = math.max(reservedRight, child.right + childBorderBoxWidth)
+      end
+      if child.top then
+        reservedTop = math.max(reservedTop, child.top + childBorderBoxHeight)
+      end
+      if child.bottom then
+        reservedBottom = math.max(reservedBottom, child.bottom + childBorderBoxHeight)
+      end
+    end
+  end
+
+  -- Calculate available space (accounting for padding and reserved space)
+  -- BORDER-BOX MODEL: element.width and element.height are already content dimensions
+  local availableWidth = element.width - reservedLeft - reservedRight
+  local availableHeight = element.height - reservedTop - reservedBottom
+
+  -- Get gaps
+  local columnGap = element.columnGap or 0
+  local rowGap = element.rowGap or 0
+
+  -- Calculate cell sizes (equal distribution)
+  local totalColumnGaps = (columns - 1) * columnGap
+  local totalRowGaps = (rows - 1) * rowGap
+  local cellWidth = (availableWidth - totalColumnGaps) / columns
+  local cellHeight = (availableHeight - totalRowGaps) / rows
+
+  -- Get children that participate in grid layout
+  local gridChildren = {}
+  for _, child in ipairs(element.children) do
+    if not (child.positioning == Positioning.ABSOLUTE and child._explicitlyAbsolute) then
+      table.insert(gridChildren, child)
+    end
+  end
+
+  -- Place children in grid cells
+  for i, child in ipairs(gridChildren) do
+    -- Calculate row and column (0-indexed for calculation)
+    local index = i - 1
+    local col = index % columns
+    local row = math.floor(index / columns)
+
+    -- Skip if we've exceeded the grid
+    if row >= rows then
+      break
+    end
+
+    -- Calculate cell position (accounting for reserved space)
+    local cellX = element.x + element.padding.left + reservedLeft + (col * (cellWidth + columnGap))
+    local cellY = element.y + element.padding.top + reservedTop + (row * (cellHeight + rowGap))
+
+    -- Apply alignment within grid cell (default to stretch)
+    local effectiveAlignItems = element.alignItems or AlignItems.STRETCH
+
+    -- Stretch child to fill cell by default
+    -- BORDER-BOX MODEL: Set border-box dimensions, content area adjusts automatically
+    if effectiveAlignItems == AlignItems.STRETCH or effectiveAlignItems == "stretch" then
+      child.x = cellX
+      child.y = cellY
+      child._borderBoxWidth = cellWidth
+      child._borderBoxHeight = cellHeight
+      child.width = math.max(0, cellWidth - child.padding.left - child.padding.right)
+      child.height = math.max(0, cellHeight - child.padding.top - child.padding.bottom)
+      -- Disable auto-sizing when stretched by grid
+      child.autosizing.width = false
+      child.autosizing.height = false
+    elseif effectiveAlignItems == AlignItems.CENTER or effectiveAlignItems == "center" then
+      local childBorderBoxWidth = child:getBorderBoxWidth()
+      local childBorderBoxHeight = child:getBorderBoxHeight()
+      child.x = cellX + (cellWidth - childBorderBoxWidth) / 2
+      child.y = cellY + (cellHeight - childBorderBoxHeight) / 2
+    elseif effectiveAlignItems == AlignItems.FLEX_START or effectiveAlignItems == "flex-start" or effectiveAlignItems == "start" then
+      child.x = cellX
+      child.y = cellY
+    elseif effectiveAlignItems == AlignItems.FLEX_END or effectiveAlignItems == "flex-end" or effectiveAlignItems == "end" then
+      local childBorderBoxWidth = child:getBorderBoxWidth()
+      local childBorderBoxHeight = child:getBorderBoxHeight()
+      child.x = cellX + cellWidth - childBorderBoxWidth
+      child.y = cellY + cellHeight - childBorderBoxHeight
+    else
+      -- Default to stretch
+      child.x = cellX
+      child.y = cellY
+      child._borderBoxWidth = cellWidth
+      child._borderBoxHeight = cellHeight
+      child.width = math.max(0, cellWidth - child.padding.left - child.padding.right)
+      child.height = math.max(0, cellHeight - child.padding.top - child.padding.bottom)
+      -- Disable auto-sizing when stretched by grid
+      child.autosizing.width = false
+      child.autosizing.height = false
+    end
+
+    -- Layout child's children if it has any
+    if #child.children > 0 then
+      child:layoutChildren()
+    end
+  end
+end
+
+return Grid