theme manager module

modules/ThemeManager.lua

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+--- ThemeManager.lua
+--- Manages theme application, state transitions, and property resolution for Elements
+--- Extracted from Element.lua as part of element-refactor-modularization task 06
+
+-- Setup module path for relative requires
+local modulePath = (...):match("(.-)[^%.]+$")
+local function req(name)
+  return require(modulePath .. name)
+end
+
+local Theme = req("Theme")
+
+---@class ThemeManager
+---@field theme string? -- Theme name to use
+---@field themeComponent string? -- Component name from theme (e.g., "button", "panel")
+---@field _themeState string -- Current theme state (normal, hover, pressed, active, disabled)
+---@field disabled boolean -- If true, element is disabled
+---@field active boolean -- If true, element is in active state (e.g., focused input)
+---@field disableHighlight boolean -- If true, disable pressed highlight overlay
+---@field scaleCorners number? -- Scale multiplier for 9-patch corners/edges
+---@field scalingAlgorithm string? -- "nearest" or "bilinear" scaling for 9-patch
+---@field _element table? -- Reference to parent Element
+local ThemeManager = {}
+ThemeManager.__index = ThemeManager
+
+--- Create new ThemeManager instance
+---@param config table Configuration options
+---@return ThemeManager
+function ThemeManager.new(config)
+  local self = setmetatable({}, ThemeManager)
+
+  -- Theme configuration
+  self.theme = config.theme
+  self.themeComponent = config.themeComponent
+  self.disabled = config.disabled or false
+  self.active = config.active or false
+  self.disableHighlight = config.disableHighlight
+  self.scaleCorners = config.scaleCorners
+  self.scalingAlgorithm = config.scalingAlgorithm
+
+  -- Internal state
+  self._themeState = "normal"
+  self._element = nil
+
+  return self
+end
+
+--- Initialize ThemeManager with parent element reference
+---@param element table The parent Element
+function ThemeManager:initialize(element)
+  self._element = element
+end
+
+--- Update theme state based on interaction state
+---@param isHovered boolean Whether element is hovered
+---@param isPressed boolean Whether element is pressed
+---@param isFocused boolean Whether element is focused
+---@param isDisabled boolean Whether element is disabled
+---@return string The new theme state
+function ThemeManager:updateState(isHovered, isPressed, isFocused, isDisabled)
+  local newState = "normal"
+
+  -- State priority: disabled > active > pressed > hover > normal
+  if isDisabled or self.disabled then
+    newState = "disabled"
+  elseif self.active then
+    newState = "active"
+  elseif isPressed then
+    newState = "pressed"
+  elseif isHovered then
+    newState = "hover"
+  end
+
+  self._themeState = newState
+  return newState
+end
+
+--- Get current theme state
+---@return string The current theme state
+function ThemeManager:getState()
+  return self._themeState
+end
+
+--- Set theme state directly
+---@param state string The theme state to set
+function ThemeManager:setState(state)
+  self._themeState = state
+end
+
+--- Check if this ThemeManager has a theme component
+---@return boolean
+function ThemeManager:hasThemeComponent()
+  return self.themeComponent ~= nil
+end
+
+--- Get the theme component name
+---@return string?
+function ThemeManager:getThemeComponent()
+  return self.themeComponent
+end
+
+--- Get the theme to use (element-specific or active theme)
+---@return table? The theme object or nil
+function ThemeManager:getTheme()
+  if self.theme then
+    return Theme.get(self.theme)
+  end
+  return Theme.getActive()
+end
+
+--- Get the component definition from the theme
+---@return table? The component definition or nil
+function ThemeManager:getComponent()
+  if not self.themeComponent then
+    return nil
+  end
+
+  local themeToUse = self:getTheme()
+  if not themeToUse or not themeToUse.components[self.themeComponent] then
+    return nil
+  end
+
+  return themeToUse.components[self.themeComponent]
+end
+
+--- Get the current state's component definition (including state-specific overrides)
+---@return table? The component definition for current state or nil
+function ThemeManager:getStateComponent()
+  local component = self:getComponent()
+  if not component then
+    return nil
+  end
+
+  -- Check for state-specific override
+  local state = self._themeState
+  if state and state ~= "normal" and component.states and component.states[state] then
+    return component.states[state]
+  end
+
+  return component
+end
+
+--- Get property value from theme for current state
+---@param property string The property name
+---@return any? The property value or nil
+function ThemeManager:getStyle(property)
+  local stateComponent = self:getStateComponent()
+  if not stateComponent then
+    return nil
+  end
+
+  return stateComponent[property]
+end
+
+--- Get the scaled content padding for current theme state
+---@param borderBoxWidth number The element's border box width
+---@param borderBoxHeight number The element's border box height
+---@return table? {left, top, right, bottom} or nil if no contentPadding
+function ThemeManager:getScaledContentPadding(borderBoxWidth, borderBoxHeight)
+  if not self.themeComponent then
+    return nil
+  end
+
+  local themeToUse = self:getTheme()
+  if not themeToUse or not themeToUse.components[self.themeComponent] then
+    return nil
+  end
+
+  local component = themeToUse.components[self.themeComponent]
+
+  -- Check for state-specific override
+  local state = self._themeState or "normal"
+  if state and state ~= "normal" and component.states and component.states[state] then
+    component = component.states[state]
+  end
+
+  if not component._ninePatchData or not component._ninePatchData.contentPadding then
+    return nil
+  end
+
+  local contentPadding = component._ninePatchData.contentPadding
+
+  -- Scale contentPadding to match the actual rendered size
+  local atlasImage = component._loadedAtlas or themeToUse.atlas
+  if atlasImage and type(atlasImage) ~= "string" then
+    local originalWidth, originalHeight = atlasImage:getDimensions()
+    local scaleX = borderBoxWidth / originalWidth
+    local scaleY = borderBoxHeight / originalHeight
+
+    return {
+      left = contentPadding.left * scaleX,
+      top = contentPadding.top * scaleY,
+      right = contentPadding.right * scaleX,
+      bottom = contentPadding.bottom * scaleY,
+    }
+  end
+
+  return nil
+end
+
+--- Get contentAutoSizingMultiplier from theme
+---@return number? The multiplier or nil
+function ThemeManager:getContentAutoSizingMultiplier()
+  if not self.themeComponent then
+    return nil
+  end
+
+  local themeToUse = self:getTheme()
+  if not themeToUse then
+    return nil
+  end
+
+  -- First check if themeComponent has a multiplier
+  if self.themeComponent then
+    local component = themeToUse.components[self.themeComponent]
+    if component and component.contentAutoSizingMultiplier then
+      return component.contentAutoSizingMultiplier
+    elseif themeToUse.contentAutoSizingMultiplier then
+      -- Fall back to theme default
+      return themeToUse.contentAutoSizingMultiplier
+    end
+  end
+
+  -- Fall back to theme default
+  if themeToUse.contentAutoSizingMultiplier then
+    return themeToUse.contentAutoSizingMultiplier
+  end
+
+  return nil
+end
+
+--- Get default font family from theme
+---@return string? The font name or path, or nil
+function ThemeManager:getDefaultFontFamily()
+  local themeToUse = self:getTheme()
+  if themeToUse and themeToUse.fonts and themeToUse.fonts["default"] then
+    return themeToUse.fonts["default"]
+  end
+  return nil
+end
+
+--- Set theme and component
+---@param themeName string? The theme name
+---@param componentName string? The component name
+function ThemeManager:setTheme(themeName, componentName)
+  self.theme = themeName
+  self.themeComponent = componentName
+end
+
+--- Get scale corners multiplier
+---@return number?
+function ThemeManager:getScaleCorners()
+  return self.scaleCorners
+end
+
+--- Get scaling algorithm
+---@return string?
+function ThemeManager:getScalingAlgorithm()
+  return self.scalingAlgorithm
+end
+
+return ThemeManager