Merge remote-tracking branch 'refs/remotes/origin/dev'

.travis.yml

@@ -20,3 +20,7 @@ install:
 
 script:
   - busted
+
+branches:
+  only:
+    - master

scene.lua

@@ -12,6 +12,12 @@ local function min_bounds(x, y, half_width, half_height)
   return x - half_width, y - half_height
 end
 
+local function insert_all(src, dest)
+  for _, value in ipairs(src) do
+    table.insert(dest, value)
+  end
+end
+
 --[[
 A node representing a local transform.
 --]]
@@ -36,6 +42,7 @@ function node:init(params)
   self.halfw = (params and params.halfw) or 0
   self.halfh = (params and params.halfh) or 0
   self._id = (params and params.id) or nil
+  self.listeners = {}
 end
 
 -- Adds id to id tables of all ancestors
@@ -187,6 +194,83 @@ function node:calc_bounds()
   end
 end
 
+function node:on(event_type, listener)
+  self.listeners[event_type] = self.listeners[event_type] or {}
+  table.insert(self.listeners[event_type], listener)
+  return listener
+end
+
+function node:off(event_type, listener)
+  if listener == nil then
+    self.listeners[event_type] = nil
+  else
+    local pos = nil
+    for i, value in ipairs(self.listeners[event_type]) do
+      if value == listener then
+        pos = i
+        break
+      end
+    end
+
+    if pos ~= nil then
+      table.remove(self.listeners[event_type], pos)
+    end
+  end
+end
+
+-- Sends event to current node only
+function node:fire(event_type, ...)
+  for _, listener in ipairs(self.listeners[event_type]) do
+    local stopLocal, stopGlobal = listener(...)
+    if stopGlobal then
+      return false
+    elseif stopLocal then
+      break
+    end
+  end
+
+  return true
+end
+
+-- Sends event to root
+function node:emit(event_type, ...)
+  if not self:fire(event_type, ...) then
+    return
+  end
+
+  if self.parent then
+    self.parent:emit(event_type, ...)
+  end
+end
+
+-- Sends event to descendents
+function node:broadcast(event_type, ...)
+  if not self:fire(event_type, ...) then
+    return
+  end
+
+  if not self.children then
+    return
+  end
+
+  -- Breadth first traversal of scene tree
+  local queue = {}
+  local qpos = 1
+  insert_all(self.children, queue)
+  while qpos <= #queue do
+    local next = queue[qpos]
+    if not next:fire(event_type, ...) then
+      return
+    end
+
+    if next.children then
+      insert_all(next.children, queue)
+    end
+
+    qpos = qpos + 1
+  end
+end
+
 scene.node = node
 
 -----------------------------------------------

spec/event_spec.lua

@@ -0,0 +1,74 @@
+local scene = require('scene')
+
+local describe = require('busted').describe
+local it = require('busted').it
+
+describe("event listeners", function()
+  it("can be attached to nodes", function()
+    local node = scene.node()
+    node:on("test", function(obj)
+      obj.test_value = true
+    end)
+
+    local event = {test_value=false}
+    node:fire("test", event)
+    assert.is_true(event.test_value)
+  end)
+
+  it("can be removed", function()
+    local node = scene.node()
+    local listener = node:on("test", function()
+      print("will be removed")
+    end)
+
+    assert.is_equal(#node.listeners["test"], 1)
+    node:off("test", listener)
+    assert.is_equal(#node.listeners["test"], 0)
+  end)
+
+  it("can be emitted", function()
+    local node1 = scene.node()
+    local node2 = scene.node()
+    local node3 = scene.node()
+
+    node1:attach(node2)
+    node2:attach(node3)
+
+    local listener = node1:on("test", function(obj)
+      obj.test_value = obj.test_value + 1
+    end)
+    node2:on("test", listener)
+    node3:on("test", listener)
+
+    local test_obj = {test_value=0}
+    node3:emit("test", test_obj)
+
+    assert.is_equal(test_obj.test_value, 3)
+  end)
+
+  it("can be broadcasted", function()
+    local node1 = scene.node{id="1"}
+    local node2 = scene.node{id="2"}
+    local node3 = scene.node{id="3"}
+
+    node1:attach(node2)
+    node1:attach(node3)
+
+    node1:on("test", function(obj)
+      table.insert(obj.received, node1)
+    end)
+    node2:on("test", function(obj)
+      table.insert(obj.received, node2)
+    end)
+    node3:on("test", function(obj)
+      table.insert(obj.received, node3)
+    end)
+
+    local test_obj = {received={}}
+    node1:broadcast("test", test_obj)
+
+    assert.is_equal(test_obj.received[1], node1)
+    assert.is_equal(test_obj.received[2], node2)
+    assert.is_equal(test_obj.received[3], node3)
+  end)
+end)