event handler and scrollmanager

modules/EventHandler.lua

@@ -0,0 +1,403 @@
+-- ====================
+-- Event Handler Module
+-- ====================
+-- Handles all user input events (mouse, keyboard, touch) for UI elements
+-- Manages event state, click detection, drag tracking, hover, and focus
+
+local modulePath = (...):match("(.-)[^%.]+$")
+local function req(name)
+  return require(modulePath .. name)
+end
+
+local InputEvent = req("InputEvent")
+local GuiState = req("GuiState")
+
+-- Get keyboard modifiers helper
+local function getModifiers()
+  return {
+    shift = love.keyboard.isDown("lshift") or love.keyboard.isDown("rshift"),
+    ctrl = love.keyboard.isDown("lctrl") or love.keyboard.isDown("rctrl"),
+    alt = love.keyboard.isDown("lalt") or love.keyboard.isDown("ralt"),
+    meta = love.keyboard.isDown("lgui") or love.keyboard.isDown("rgui"),
+  }
+end
+
+---@class EventHandler
+local EventHandler = {}
+EventHandler.__index = EventHandler
+
+--- Create a new EventHandler instance
+---@param config table Configuration options
+---@return EventHandler
+function EventHandler.new(config)
+  config = config or {}
+  
+  local self = setmetatable({}, EventHandler)
+  
+  -- Event callback
+  self.onEvent = config.onEvent
+  
+  -- Mouse button state tracking {button -> boolean}
+  self._pressed = config._pressed or {}
+  
+  -- Click detection state
+  self._lastClickTime = config._lastClickTime
+  self._lastClickButton = config._lastClickButton
+  self._clickCount = config._clickCount or 0
+  
+  -- Drag tracking per button {button -> position}
+  self._dragStartX = config._dragStartX or {}
+  self._dragStartY = config._dragStartY or {}
+  self._lastMouseX = config._lastMouseX or {}
+  self._lastMouseY = config._lastMouseY or {}
+  
+  -- Touch state tracking {touchId -> boolean}
+  self._touchPressed = config._touchPressed or {}
+  
+  -- Hover state
+  self._hovered = config._hovered or false
+  
+  -- Reference to parent element (set via initialize)
+  self._element = nil
+  
+  -- Scrollbar press tracking flag
+  self._scrollbarPressHandled = false
+  
+  return self
+end
+
+--- Initialize EventHandler with parent element reference
+---@param element Element The parent element
+function EventHandler:initialize(element)
+  self._element = element
+end
+
+--- Get state for persistence (for immediate mode)
+---@return table State data
+function EventHandler:getState()
+  return {
+    _pressed = self._pressed,
+    _lastClickTime = self._lastClickTime,
+    _lastClickButton = self._lastClickButton,
+    _clickCount = self._clickCount,
+    _dragStartX = self._dragStartX,
+    _dragStartY = self._dragStartY,
+    _lastMouseX = self._lastMouseX,
+    _lastMouseY = self._lastMouseY,
+    _hovered = self._hovered,
+  }
+end
+
+--- Restore state from persistence (for immediate mode)
+---@param state table State data
+function EventHandler:setState(state)
+  if not state then return end
+  
+  self._pressed = state._pressed or {}
+  self._lastClickTime = state._lastClickTime
+  self._lastClickButton = state._lastClickButton
+  self._clickCount = state._clickCount or 0
+  self._dragStartX = state._dragStartX or {}
+  self._dragStartY = state._dragStartY or {}
+  self._lastMouseX = state._lastMouseX or {}
+  self._lastMouseY = state._lastMouseY or {}
+  self._hovered = state._hovered or false
+end
+
+--- Process mouse button events in the update cycle
+---@param mx number Mouse X position
+---@param my number Mouse Y position
+---@param isHovering boolean Whether mouse is over element
+---@param isActiveElement boolean Whether this is the top element at mouse position
+function EventHandler:processMouseEvents(mx, my, isHovering, isActiveElement)
+  if not self._element then
+    return
+  end
+  
+  local element = self._element
+  
+  -- Check if currently dragging (allows drag continuation even if occluded)
+  local isDragging = false
+  for _, button in ipairs({ 1, 2, 3 }) do
+    if self._pressed[button] and love.mouse.isDown(button) then
+      isDragging = true
+      break
+    end
+  end
+  
+  -- Can only process events if we have handler, element is enabled, and is active or dragging
+  local canProcessEvents = (self.onEvent or element.editable) and not element.disabled and (isActiveElement or isDragging)
+  
+  if not canProcessEvents then
+    return
+  end
+  
+  -- Process all three mouse buttons
+  local buttons = { 1, 2, 3 } -- left, right, middle
+  
+  for _, button in ipairs(buttons) do
+    if isHovering or isDragging then
+      if love.mouse.isDown(button) then
+        -- Button is pressed down
+        if not self._pressed[button] then
+          -- Just pressed - fire press event
+          self:_handleMousePress(mx, my, button)
+        else
+          -- Button is still pressed - check for drag
+          self:_handleMouseDrag(mx, my, button, isHovering)
+        end
+      elseif self._pressed[button] then
+        -- Button was just released - fire click and release events
+        self:_handleMouseRelease(mx, my, button)
+      end
+    else
+      -- Mouse left the element - reset pressed state and drag tracking
+      if self._pressed[button] then
+        self._pressed[button] = false
+        self._dragStartX[button] = nil
+        self._dragStartY[button] = nil
+      end
+    end
+  end
+end
+
+--- Handle mouse button press
+---@param mx number Mouse X position
+---@param my number Mouse Y position
+---@param button number Mouse button (1=left, 2=right, 3=middle)
+function EventHandler:_handleMousePress(mx, my, button)
+  if not self._element then return end
+  
+  local element = self._element
+  
+  -- Check if press is on scrollbar first (skip if already handled)
+  if button == 1 and not self._scrollbarPressHandled and element._handleScrollbarPress then
+    if element:_handleScrollbarPress(mx, my, button) then
+      -- Scrollbar consumed the event, mark as pressed to prevent onEvent
+      self._pressed[button] = true
+      self._scrollbarPressHandled = true
+      return
+    end
+  end
+  
+  -- Fire press event
+  if self.onEvent then
+    local modifiers = getModifiers()
+    local pressEvent = InputEvent.new({
+      type = "press",
+      button = button,
+      x = mx,
+      y = my,
+      modifiers = modifiers,
+      clickCount = 1,
+    })
+    self.onEvent(element, pressEvent)
+  end
+  
+  self._pressed[button] = true
+  
+  -- Set mouse down position for text selection on left click
+  if button == 1 and element._textEditor then
+    element._mouseDownPosition = element._textEditor:mouseToTextPosition(mx, my)
+    element._textDragOccurred = false -- Reset drag flag on press
+  end
+  
+  -- Record drag start position per button
+  self._dragStartX[button] = mx
+  self._dragStartY[button] = my
+  self._lastMouseX[button] = mx
+  self._lastMouseY[button] = my
+end
+
+--- Handle mouse drag (while button is pressed and mouse moves)
+---@param mx number Mouse X position
+---@param my number Mouse Y position
+---@param button number Mouse button
+---@param isHovering boolean Whether mouse is over element
+function EventHandler:_handleMouseDrag(mx, my, button, isHovering)
+  if not self._element then return end
+  
+  local element = self._element
+  
+  local lastX = self._lastMouseX[button] or mx
+  local lastY = self._lastMouseY[button] or my
+  
+  if lastX ~= mx or lastY ~= my then
+    -- Mouse has moved - fire drag event only if still hovering
+    if self.onEvent and isHovering then
+      local modifiers = getModifiers()
+      local dx = mx - self._dragStartX[button]
+      local dy = my - self._dragStartY[button]
+      
+      local dragEvent = InputEvent.new({
+        type = "drag",
+        button = button,
+        x = mx,
+        y = my,
+        dx = dx,
+        dy = dy,
+        modifiers = modifiers,
+        clickCount = 1,
+      })
+      self.onEvent(element, dragEvent)
+    end
+    
+    -- Handle text selection drag for editable elements
+    if button == 1 and element.editable and element._focused and element._handleTextDrag then
+      element:_handleTextDrag(mx, my)
+    end
+    
+    -- Update last known position for this button
+    self._lastMouseX[button] = mx
+    self._lastMouseY[button] = my
+  end
+end
+
+--- Handle mouse button release
+---@param mx number Mouse X position
+---@param my number Mouse Y position
+---@param button number Mouse button
+function EventHandler:_handleMouseRelease(mx, my, button)
+  if not self._element then return end
+  
+  local element = self._element
+  
+  local currentTime = love.timer.getTime()
+  local modifiers = getModifiers()
+  
+  -- Determine click count (double-click detection)
+  local clickCount = 1
+  local doubleClickThreshold = 0.3 -- 300ms for double-click
+  
+  if self._lastClickTime and self._lastClickButton == button and (currentTime - self._lastClickTime) < doubleClickThreshold then
+    clickCount = self._clickCount + 1
+  else
+    clickCount = 1
+  end
+  
+  self._clickCount = clickCount
+  self._lastClickTime = currentTime
+  self._lastClickButton = button
+  
+  -- Determine event type based on button
+  local eventType = "click"
+  if button == 2 then
+    eventType = "rightclick"
+  elseif button == 3 then
+    eventType = "middleclick"
+  end
+  
+  -- Fire click event
+  if self.onEvent then
+    local clickEvent = InputEvent.new({
+      type = eventType,
+      button = button,
+      x = mx,
+      y = my,
+      modifiers = modifiers,
+      clickCount = clickCount,
+    })
+    self.onEvent(element, clickEvent)
+  end
+  
+  self._pressed[button] = false
+  
+  -- Clean up drag tracking
+  self._dragStartX[button] = nil
+  self._dragStartY[button] = nil
+  
+  -- Clean up text selection drag tracking
+  if button == 1 then
+    element._mouseDownPosition = nil
+  end
+  
+  -- Focus editable elements on left click
+  if button == 1 and element.editable then
+    -- Only focus if not already focused (to avoid moving cursor to end)
+    local wasFocused = element:isFocused()
+    if not wasFocused then
+      element:focus()
+    end
+    
+    -- Handle text click for cursor positioning and word selection
+    -- Only process click if no text drag occurred (to preserve drag selection)
+    if element._handleTextClick and not element._textDragOccurred then
+      element:_handleTextClick(mx, my, clickCount)
+    end
+    
+    -- Reset drag flag after release
+    element._textDragOccurred = false
+  end
+  
+  -- Fire release event
+  if self.onEvent then
+    local releaseEvent = InputEvent.new({
+      type = "release",
+      button = button,
+      x = mx,
+      y = my,
+      modifiers = modifiers,
+      clickCount = clickCount,
+    })
+    self.onEvent(element, releaseEvent)
+  end
+end
+
+--- Process touch events in the update cycle
+function EventHandler:processTouchEvents()
+  if not self._element or not self.onEvent then
+    return
+  end
+  
+  local element = self._element
+  
+  local bx = element.x
+  local by = element.y
+  local bw = element._borderBoxWidth or (element.width + element.padding.left + element.padding.right)
+  local bh = element._borderBoxHeight or (element.height + element.padding.top + element.padding.bottom)
+  
+  local touches = love.touch.getTouches()
+  for _, id in ipairs(touches) do
+    local tx, ty = love.touch.getPosition(id)
+    if tx >= bx and tx <= bx + bw and ty >= by and ty <= by + bh then
+      self._touchPressed[id] = true
+    elseif self._touchPressed[id] then
+      -- Create touch event (treat as left click)
+      local touchEvent = InputEvent.new({
+        type = "click",
+        button = 1,
+        x = tx,
+        y = ty,
+        modifiers = getModifiers(),
+        clickCount = 1,
+      })
+      self.onEvent(element, touchEvent)
+      self._touchPressed[id] = false
+    end
+  end
+end
+
+--- Reset scrollbar press flag (called each frame)
+function EventHandler:resetScrollbarPressFlag()
+  self._scrollbarPressHandled = false
+end
+
+--- Check if any mouse button is pressed
+---@return boolean True if any button is pressed
+function EventHandler:isAnyButtonPressed()
+  for _, pressed in pairs(self._pressed) do
+    if pressed then
+      return true
+    end
+  end
+  return false
+end
+
+--- Check if a specific button is pressed
+---@param button number Mouse button (1=left, 2=right, 3=middle)
+---@return boolean True if button is pressed
+function EventHandler:isButtonPressed(button)
+  return self._pressed[button] == true
+end
+
+return EventHandler