allow events bound to widget classes

example/main.lua

@@ -60,7 +60,7 @@ local mainForm = { title = "Test window", id = 'mainWindow', type = 'panel',
         { type = 'sash', width = 4, },
         { type = 'panel', id = 'rightSideBox', width = 200,
             { type = 'panel', text = 'A slider', align = 'bottom', height = 24, padding = 4 },
-            { type = 'slider', height = 32, padding = 4 },
+            { type = 'slider', height = 32, padding = 4, id = 'slidey', },
             { type = 'panel', text = 'A stepper', align = 'bottom', height = 24, padding = 4 },
             { type = 'stepper', height = 32, padding = 4, options = {
                 { value = 1, text = 'Thing One' },
@@ -89,6 +89,11 @@ layout.leftSideBox:addChild {
     align = 'middle right'
 }
 
+layout.slidey:onMotion(function (event)
+    layout.statusbar.text = event.x
+    return false
+end)
+
 --[[
 local KEY_ESCAPE = 27
 

luigi/event.lua

@@ -3,22 +3,26 @@ local ROOT = (...):gsub('[^.]*$', '')
 local Base = require(ROOT .. 'base')
 local Hooker = require(ROOT .. 'hooker')
 
-local Event = Base:extend({ name = 'Event' })
+local Event = Base:extend { name = 'Event' }
 
-function Event:emit (observer, data, defaultAction)
+function Event:emit (target, data, defaultAction)
-    local callbacks = self.registry[observer]
+    while target do
-    if not callbacks then
+        local handlers = rawget(target, 'eventHandlers')
-        if defaultAction then defaultAction() end
+        local callbacks = handlers and handlers[self.name]
-        return
+        if callbacks then
+            local result = callbacks(data or {})
+            if result ~= nil then return result end
+        end
+        target = target.widgetClass
     end
-    local result = callbacks(data or {})
-    if result ~= nil then return result end
     if defaultAction then defaultAction() end
 end
 
-function Event:bind (observer, callback)
+function Event:bind (target, callback)
-    local registry = self.registry
+    if not rawget(target, 'eventHandlers') then
-    return Hooker.hook(registry, observer, callback)
+        target.eventHandlers = {}
+    end
+    return Hooker.hook(target.eventHandlers, self.name, callback)
 end
 
 local eventNames = {
@@ -30,10 +34,7 @@ local eventNames = {
 local weakKeyMeta = { __mode = 'k' }
 
 for i, name in ipairs(eventNames) do
-    Event[name] = Event:extend({
+    Event[name] = Event:extend { name = name }
-        name = name,
-        registry = setmetatable({}, weakKeyMeta),
-    })
 end
 
 function Event.injectBinders (t)

luigi/renderer.lua

@@ -252,7 +252,7 @@ function Renderer:renderChildren (widget)
 end
 
 function Renderer:render (widget)
-    Event.Display:emit(widget, {}, function()
+    Event.Display:emit(widget, { target = widget }, function()
         self:renderBackground(widget)
         self:renderOutline(widget)
         self:renderSlices(widget)

luigi/widget.lua

@@ -25,6 +25,9 @@ function Widget.create (layout, data)
 end
 
 function Widget:constructor (layout, data)
+    local meta = getmetatable(self)
+    local metaIndex = meta.__index
+    self.widgetClass = metaIndex
     self.type = 'generic'
     self.layout = layout
     self.children = {}
@@ -33,15 +36,13 @@ function Widget:constructor (layout, data)
     self:extract(data)
     layout:addWidget(self)
     local widget = self
-    local meta = getmetatable(self)
-    local metaIndex = meta.__index
     function meta:__index(property)
         local value = metaIndex[property]
-        local style = widget.layout.style
-        local theme = widget.layout.theme
         if value ~= nil then return value end
+        local style = widget.layout.style
         value = style and style:getProperty(self, property)
         if value ~= nil then return value end
+        local theme = widget.layout.theme
         return theme and theme:getProperty(self, property)
     end
 end

luigi/widget/sash.lua

@@ -2,36 +2,32 @@ local Widget = require((...):gsub('%.[^.]*$', ''))
 
 local Sash = Widget:extend()
 
-function Sash:constructor (layout, data)
+Sash:onPressDrag(function (event)
-    Widget.constructor(self, layout, data)
+    local self = event.target
+    local axis = self.parent.flow
+    if axis == 'x' then
+        dimension = 'width'
+    else
+        axis = 'y'
+        dimension = 'height'
+    end
+    local prevSibling = self:getPrevious()
+    local nextSibling = self:getNext()
+    local prevSize = prevSibling and prevSibling[dimension]
+    local nextSize = nextSibling and nextSibling[dimension]
+    if prevSize then
+        prevSibling:setDimension(dimension,
+                event[axis] - prevSibling:calculatePosition(axis))
+    end
+    if nextSize then
+        nextSibling:setDimension(dimension,
+                nextSibling:calculatePosition(axis) +
+                nextSibling[dimension] - event[axis])
+    end
 
-    self:onPressDrag(function (event)
+    prevSibling:reflow()
-        local axis = self.parent.flow
+    nextSibling:reflow()
-        if axis == 'x' then
+    self:reflow()
-            dimension = 'width'
+end)
-        else
-            axis = 'y'
-            dimension = 'height'
-        end
-        local prevSibling = self:getPrevious()
-        local nextSibling = self:getNext()
-        local prevSize = prevSibling and prevSibling[dimension]
-        local nextSize = nextSibling and nextSibling[dimension]
-        if prevSize then
-            prevSibling:setDimension(dimension,
-                    event[axis] - prevSibling:calculatePosition(axis))
-        end
-        if nextSize then
-            nextSibling:setDimension(dimension,
-                    nextSibling:calculatePosition(axis) +
-                    nextSibling[dimension] - event[axis])
-        end
-
-        prevSibling:reflow()
-        nextSibling:reflow()
-        self:reflow()
-    end)
-
-end
 
 return Sash

luigi/widget/slider.lua

@@ -6,47 +6,48 @@ function Slider:constructor (layout, data)
     Widget.constructor(self, layout, data)
 
     self.value = 0.5
-
-    self:onPressDrag(function (event)
-        local x1, y1, x2, y2 = self:getRectangle(true, true)
-        self.value = (event.x - x1) / (x2 - x1)
-        if self.value < 0 then self.value = 0 end
-        if self.value > 1 then self.value = 1 end
-    end)
-
-    self:onDisplay(function (event)
-        local x1, y1, x2, y2 = self:getRectangle(true, true)
-        local padding = self.padding or 0
-
-        local sx1 = math.floor(x1 + self.value * (x2 - x1) - padding) + 0.5
-        local sy1 = math.floor(y1 + padding) + 0.5
-        local sx2 = padding * 2
-        local sy2 = y2 - y1 - padding
-
-        love.graphics.push('all')
-
-        love.graphics.setColor(self.outline)
-
-        love.graphics.rectangle('fill',
-            x1,
-            y1 + ((y2 - y1) / 2),
-            x2 - x1,
-            padding
-        )
-
-        love.graphics.setColor(self.background)
-
-        love.graphics.rectangle('fill', sx1, sy1, sx2, sy2)
-
-        love.graphics.setColor(self.outline)
-
-        love.graphics.rectangle('line', sx1, sy1, sx2, sy2)
-
-        love.graphics.pop()
-
-        return false
-    end)
-
 end
 
+Slider:onPressDrag(function (event)
+    local self = event.target
+    local x1, y1, x2, y2 = self:getRectangle(true, true)
+    self.value = (event.x - x1) / (x2 - x1)
+    if self.value < 0 then self.value = 0 end
+    if self.value > 1 then self.value = 1 end
+end)
+
+Slider:onDisplay(function (event)
+    local self = event.target
+    local x1, y1, x2, y2 = self:getRectangle(true, true)
+    local padding = self.padding or 0
+
+    local sx1 = math.floor(x1 + self.value * (x2 - x1) - padding) + 0.5
+    local sy1 = math.floor(y1 + padding) + 0.5
+    local sx2 = padding * 2
+    local sy2 = y2 - y1 - padding
+
+    love.graphics.push('all')
+
+    love.graphics.setColor(self.outline)
+
+    love.graphics.rectangle('fill',
+        x1,
+        y1 + ((y2 - y1) / 2),
+        x2 - x1,
+        padding
+    )
+
+    love.graphics.setColor(self.background)
+
+    love.graphics.rectangle('fill', sx1, sy1, sx2, sy2)
+
+    love.graphics.setColor(self.outline)
+
+    love.graphics.rectangle('line', sx1, sy1, sx2, sy2)
+
+    love.graphics.pop()
+
+    return false
+end)
+
 return Slider