Add legacy panel classes to support old theme selectors

Signed-off-by: Max Brunsfeld <maxbrunsfeld@gmail.com>

spec/panel-container-element-spec.coffee

@@ -51,6 +51,7 @@ describe "PanelContainerElement", ->
         container.addPanel(panel1)
         expect(element.childNodes.length).toBe 1
         expect(element.childNodes[0]).toHaveClass 'left'
+        expect(element.childNodes[0]).toHaveClass 'panel-left' # legacy selector support
 
         expect(element.childNodes[0].tagName).toBe 'ATOM-PANEL'
 
@@ -80,6 +81,7 @@ describe "PanelContainerElement", ->
         container.addPanel(panel1)
         expect(element.childNodes.length).toBe 1
         expect(element.childNodes[0]).toHaveClass 'bottom'
+        expect(element.childNodes[0]).toHaveClass 'panel-bottom' # legacy selector support
         expect(element.childNodes[0].tagName).toBe 'ATOM-PANEL'
         expect(panel1.getView()).toHaveClass 'one'
 
@@ -116,3 +118,11 @@ describe "PanelContainerElement", ->
 
       expect(panel1.getView().style.display).not.toBe 'none'
       expect(panel2.getView().style.display).toBe 'none'
+
+    it "adds the 'modal' class to panels", ->
+      panel1 = new Panel({viewRegistry, item: new TestPanelContainerItem()})
+      container.addPanel(panel1)
+
+      expect(panel1.getView()).toHaveClass 'modal'
+      expect(panel1.getView()).toHaveClass 'overlay' # legacy selector support
+      expect(panel1.getView()).toHaveClass 'from-top' # legacy selector support

src/panel-container-element.coffee

@@ -15,6 +15,11 @@ class PanelContainerElement extends HTMLElement
   panelAdded: ({panel, index}) ->
     panelElement = panel.getView()
     panelElement.classList.add(@model.getLocation())
+    if @model.isModal()
+      panelElement.classList.add("overlay")
+    else
+      panelElement.classList.add("panel-#{@model.getLocation()}")
+
     if index >= @childNodes.length
       @appendChild(panelElement)
     else

src/panel-element.coffee

@@ -12,6 +12,7 @@ class PanelElement extends HTMLElement
     @appendChild(view)
     callAttachHooks(view) # for backward compatibility with SpacePen views
 
+    @classList.add("tool-panel")
     @classList.add(@model.getClassName().split(' ')...) if @model.getClassName()?
     @subscriptions.add @model.onDidChangeVisible(@visibleChanged.bind(this))
     @subscriptions.add @model.onDidDestroy(@destroyed.bind(this))