fix(fullscreen): On Mac OS X, green window control defaults to fullscreen

src/sheet-toolbar.cjsx

@@ -71,13 +71,35 @@ class ToolbarBack extends React.Component
 
 class ToolbarWindowControls extends React.Component
   @displayName: 'ToolbarWindowControls'
+  constructor: (@props) ->
+    @state = {alt: false}
+
+  componentDidMount: =>
+    if process.platform is 'darwin'
+      window.addEventListener('keydown', @_onAlt)
+      window.addEventListener('keyup', @_onAlt)
+
+  componentWillUnmount: =>
+    if process.platform is 'darwin'
+      window.removeEventListener('keydown', @_onAlt)
+      window.removeEventListener('keyup', @_onAlt)
+
   render: =>
-    <div name="ToolbarWindowControls" className="toolbar-window-controls">
+    <div name="ToolbarWindowControls" className="toolbar-window-controls alt-#{@state.alt}">
       <button className="close" onClick={ -> atom.close()}></button>
       <button className="minimize" onClick={ -> atom.minimize()}></button>
-      <button className="maximize" onClick={ -> atom.maximize()}></button>
+      <button className="maximize" onClick={@_onMaximize}></button>
     </div>
 
+  _onAlt: (event) =>
+    @setState(alt: event.altKey) if @state.alt isnt event.altKey
+
+  _onMaximize: (event) =>
+    if process.platform is 'darwin' and not event.altKey
+      atom.setFullScreen(!atom.isFullScreen())
+    else
+      atom.maximize()
+
 class ToolbarMenuControl extends React.Component
   @displayName: 'ToolbarMenuControl'
   render: =>

static/workspace.less

@@ -107,10 +107,15 @@ atom-workspace {
   .minimize {
     background-image: url("images/application-frame/minimize@1x.png");
   }
+  .maximize {
+    background-image: url("images/application-frame/fullscreen@1x.png");
+  }
+  &.alt-true {
     .maximize {
       background-image: url("images/application-frame/maximize@1x.png");
     }
   }
+}
 
 @media (-webkit-min-device-pixel-ratio: 2) {
   .toolbar-window-controls {
@@ -120,11 +125,16 @@ atom-workspace {
     .minimize {
       background-image: url("images/application-frame/minimize@2x.png");
     }
+    .maximize {
+      background-image: url("images/application-frame/fullscreen@2x.png");
+    }
+    &.alt-true {
       .maximize {
         background-image: url("images/application-frame/maximize@2x.png");
       }
     }
   }
+}
 
 body.is-blurred {
   .toolbar-window-controls {