Added temporary tabs

lib/main.coffee

@@ -13,6 +13,10 @@ module.exports =
     tabScrollingThreshold:
       type: 'integer'
       default: 120
+    usePreviewTabs:
+      type: 'boolean'
+      default: true
+      description: 'Tabs will only stay open if they are modified or double-clicked'
 
   activate: ->
     @tabBarViews = []

lib/tab-bar-view.coffee

@@ -2,7 +2,7 @@ BrowserWindow = null # Defer require until actually used
 RendererIpc = require 'ipc'
 
 {$, View} = require 'atom-space-pen-views'
-{CompositeDisposable} = require 'atom'
+{CompositeDisposable, TextEditor} = require 'atom'
 _ = require 'underscore-plus'
 TabView = require './tab-view'
 
@@ -46,7 +46,11 @@ class TabBarView extends View
     @subscriptions.add @pane.onDidRemoveItem ({item}) =>
       @removeTabForItem(item)
 
-    @subscriptions.add @pane.onDidChangeActiveItem =>
+    @subscriptions.add @pane.onDidChangeActiveItem (item) =>
+      if atom.config.get('tabs.usePreviewTabs') and item instanceof TextEditor
+        if @getTabs().length > 1 and @tab.item isnt item and @tab.isPreviewTab
+          @pane.destroyItem @tab.item
+        @tab = @tabForItem(item)
       @updateActiveTab()
 
     @subscriptions.add atom.config.observe 'tabs.tabScrolling', => @updateTabScrolling()
@@ -88,6 +92,8 @@ class TabBarView extends View
   addTabForItem: (item, index) ->
     tabView = new TabView()
     tabView.initialize(item)
+    if atom.config.get('tabs.usePreviewTabs') and not @tab and item instanceof TextEditor
+      @tab = tabView
     @insertTabAtIndex(tabView, index)
 
   moveItemTabToIndex: (item, index) ->

lib/tab-view.coffee

@@ -1,12 +1,21 @@
 path = require 'path'
 {$} = require 'atom-space-pen-views'
+{TextEditor} = require 'atom'
 
 module.exports =
 class TabView extends HTMLElement
   initialize: (@item) ->
+    @isPreviewTab = false
+    if atom.config.get('tabs.usePreviewTabs') and @item instanceof TextEditor
+      @isPreviewTab = true
+      @addEventListener 'dblclick', =>
+        @isPreviewTab = false
+        @itemTitle.classList.remove('temp')
+
     @classList.add('tab', 'sortable')
 
     @itemTitle = document.createElement('div')
+    @itemTitle.classList.add('temp') if @isPreviewTab
     @itemTitle.classList.add('title')
     @appendChild(@itemTitle)
 
@@ -156,6 +165,9 @@ class TabView extends HTMLElement
 
   updateModifiedStatus: ->
     if @item.isModified?()
+      if atom.config.get('tabs.usePreviewTabs')
+        @isPreviewTab = false
+        @itemTitle.classList.remove('temp')
       @classList.add('modified') unless @isModified
       @isModified = true
     else

spec/tabs-spec.coffee

@@ -709,3 +709,86 @@ describe "TabBarView", ->
         pane.destroyItem(item2)
         expect(pane.getItems().length).toBe 1
         expect(tabBar.element).toHaveClass 'hidden'
+
+  describe "when usePreviewTabs is true in package settings", ->
+    beforeEach ->
+      atom.config.set("tabs.usePreviewTabs", true)
+      pane.destroyItems()
+
+    describe "when opening a new tab", ->
+      it "adds tab with class 'temp'", ->
+        editor1 = null
+        waitsForPromise ->
+          atom.project.open('sample.txt').then (o) -> editor1 = o
+        runs ->
+          pane.activateItem(editor1)
+          expect(tabBar.find('.tab .temp').length).toBe 1
+          expect(tabBar.find('.tab:eq(0) .title')).toHaveClass 'temp'
+
+    describe "when there is a temp tab already", ->
+      it "it will replace an existing temporary tab", ->
+        editor1 = null
+        editor2 = null
+
+        waitsForPromise ->
+          atom.project.open('sample.txt').then (o) ->
+            editor1 = o
+            pane.activateItem(editor1)
+            atom.project.open('sample2.txt').then (o) ->
+              editor2 = o
+              pane.activateItem(editor2)
+
+        runs ->
+          expect(editor1.isDestroyed()).toBe true
+          expect(editor2.isDestroyed()).toBe false
+          expect(tabBar.tabForItem(editor1)).not.toExist()
+          expect($(tabBar.tabForItem(editor2)).find('.title')).toHaveClass 'temp'
+      it 'makes the tab permanent when dbl clicking the tab', ->
+        editor2 = null
+
+        waitsForPromise ->
+          atom.project.open('sample.txt').then (o) -> editor2 = o
+
+        runs ->
+          pane.activateItem(editor2)
+          dbclickEvt = document.createEvent 'MouseEvents'
+          dbclickEvt.initEvent 'dblclick'
+          tabBar.tabForItem(editor2).dispatchEvent dbclickEvt
+          expect($(tabBar.tabForItem(editor2)).find('.title')).not.toHaveClass 'temp'
+
+    describe 'when opening views that do not contain an editor', ->
+      editor2 = null
+      settingsView = null
+
+      beforeEach ->
+        waitsForPromise ->
+          atom.project.open('sample.txt').then (o) ->
+            editor2 = o
+            pane.activateItem(editor2)
+
+        waitsForPromise ->
+          atom.packages.activatePackage('settings-view').then ->
+            atom.workspace.open('atom://config').then (o) ->
+              settingsView = o
+              pane.activateItem(settingsView)
+
+      it 'creates a permanent tab', ->
+        expect(tabBar.tabForItem(settingsView)).toExist()
+        expect($(tabBar.tabForItem(settingsView)).find('.title')).not.toHaveClass 'temp'
+
+      it 'keeps an existing temp tab', ->
+        expect(tabBar.tabForItem(editor2)).toExist()
+        expect($(tabBar.tabForItem(editor2)).find('.title')).toHaveClass 'temp'
+
+    describe 'when editing a file', ->
+      it 'makes the tab permanent', ->
+        editor1 = null
+        waitsForPromise ->
+          atom.workspace.open('sample.txt').then (o) ->
+            editor1 = o
+            pane.activateItem(editor1)
+            editor1.insertText('x')
+            advanceClock(editor1.buffer.stoppedChangingDelay)
+
+        runs ->
+          expect($(tabBar.tabForItem(editor1)).find('.title')).not.toHaveClass 'temp'

styles/tabs.less

@@ -31,6 +31,9 @@
       overflow: hidden;
       white-space: nowrap;
       text-overflow: ellipsis;
+      &.temp {
+        font-style: italic;
+      }
     }
 
     .hide-icon {