Modifiers key modifier for directive on of Vue.js 2.0 (#4034)

* Modifiers key modifier for directive on

* meta modifier key modifier for directive on

* Code format

Author: KingMario

src/compiler/codegen/events.js

@@ -18,7 +18,11 @@ const keyCodes = {
 const modifierCode = {
   stop: '$event.stopPropagation();',
   prevent: '$event.preventDefault();',
-  self: 'if($event.target !== $event.currentTarget)return;'
+  self: 'if($event.target !== $event.currentTarget)return;',
+  ctrl: 'if(!$event.ctrlKey)return;',
+  shift: 'if(!$event.shiftKey)return;',
+  alt: 'if(!$event.altKey)return;',
+  meta: 'if(!$event.metaKey)return;'
 }
 
 export function genHandlers (events: ASTElementHandlers, native?: boolean): string {

test/unit/modules/compiler/codegen.spec.js

@@ -224,6 +224,22 @@ describe('codegen', () => {
       '<input @input.self="onInput">',
       `with(this){return _h('input',{on:{"input":function($event){if($event.target !== $event.currentTarget)return;onInput($event)}}})}`
     )
+    assertCodegen(
+      '<input @input.ctrl="onInput">',
+      `with(this){return _h('input',{on:{"input":function($event){if(!$event.ctrlKey)return;onInput($event)}}})}`
+    )
+    assertCodegen(
+      '<input @input.shift="onInput">',
+      `with(this){return _h('input',{on:{"input":function($event){if(!$event.shiftKey)return;onInput($event)}}})}`
+    )
+    assertCodegen(
+      '<input @input.alt="onInput">',
+      `with(this){return _h('input',{on:{"input":function($event){if(!$event.altKey)return;onInput($event)}}})}`
+    )
+    assertCodegen(
+      '<input @input.meta="onInput">',
+      `with(this){return _h('input',{on:{"input":function($event){if(!$event.metaKey)return;onInput($event)}}})}`
+    )
   })
 
   it('generate events with multiple modifers', () => {