Resolves #170, thang can be directly placed by dragging onto the map

app/lib/surface/Surface.coffee

@@ -103,6 +103,7 @@ module.exports = Surface = class Surface extends CocoClass
     @stage.removeAllChildren()
     @stage.removeEventListener 'stagemousemove', @onMouseMove
     @stage.removeEventListener 'stagemousedown', @onMouseDown
+    @stage.removeEventListener 'stagemouseup', @onMouseUp
     @stage.removeAllEventListeners()
     @stage.enableDOMEvents false
     @stage.enableMouseOver 0
@@ -416,6 +417,7 @@ module.exports = Surface = class Surface extends CocoClass
     @stage.enableMouseOver(10)
     @stage.addEventListener 'stagemousemove', @onMouseMove
     @stage.addEventListener 'stagemousedown', @onMouseDown
+    @stage.addEventListener 'stagemouseup', @onMouseUp
     @canvas.on 'mousewheel', @onMouseWheel
     @hookUpChooseControls() if @options.choosing
     createjs.Ticker.timingMode = createjs.Ticker.RAF_SYNCHED
@@ -539,6 +541,11 @@ module.exports = Surface = class Surface extends CocoClass
     onBackground = not @stage.hitTest e.stageX, e.stageY
     Backbone.Mediator.publish 'surface:stage-mouse-down', onBackground: onBackground, x: e.stageX, y: e.stageY, originalEvent: e
 
+  onMouseUp: (e) =>
+    return if @disabled
+    onBackground = not @stage.hitTest e.stageX, e.stageY
+    Backbone.Mediator.publish 'surface:stage-mouse-up', onBackground: onBackground, x: e.stageX, y: e.stageY, originalEvent: e
+
   onMouseWheel: (e) =>
     # https://github.com/brandonaaron/jquery-mousewheel
     e.preventDefault()

app/views/editor/level/thangs_tab_view.coffee

@@ -43,7 +43,7 @@ module.exports = class ThangsTabView extends View
     'sprite:dragged': 'onSpriteDragged'
     'sprite:mouse-up': 'onSpriteMouseUp'
     'sprite:double-clicked': 'onSpriteDoubleClicked'
-    'surface:stage-mouse-down': 'onStageMouseDown'
+    'surface:stage-mouse-up': 'onStageMouseUp'
 
   events:
     'click #extant-thangs-filter button': 'onFilterExtantThangs'
@@ -108,7 +108,7 @@ module.exports = class ThangsTabView extends View
   afterRender: ->
     super()
     return unless @supermodel.finished()
-    $('.tab-content').click @selectAddThang
+    $('.tab-content').mousedown @selectAddThang
     $('#thangs-list').bind 'mousewheel', @preventBodyScrollingInThangList
     @$el.find('#extant-thangs-filter button:first').button('toggle')
     $(window).resize @onWindowResize
@@ -185,7 +185,7 @@ module.exports = class ThangsTabView extends View
     if e.originalEvent.nativeEvent.button == 2
       @onSpriteContextMenu e
 
-  onStageMouseDown: (e) ->
+  onStageMouseUp: (e) ->
     if @addThangSprite
       # If we click on the background, we need to add @addThangSprite, but not if onSpriteMouseDown will fire.
       @backgroundAddClickTimeout = _.defer => @onExtantThangSelected {}