Merge pull request #4390 from atom/bo-panel-for-item

Add Workspace::panelForItem()

spec/workspace-spec.coffee

@@ -543,3 +543,13 @@ describe "Workspace", ->
         itemView = atom.views.getView(atom.workspace.getModalPanels()[0].getItem())
         expect(itemView instanceof TestItemElement).toBe(true)
         expect(itemView.getModel()).toBe(model)
+
+    describe "::panelForItem(item)", ->
+      it "returns the panel associated with the item", ->
+        item = new TestItem
+        panel = atom.workspace.addLeftPanel(item: item)
+
+        itemWithNoPanel = new TestItem
+
+        expect(atom.workspace.panelForItem(item)).toBe panel
+        expect(atom.workspace.panelForItem(itemWithNoPanel)).toBe null

src/panel-container.coffee

@@ -48,6 +48,11 @@ class PanelContainer
     @emitter.emit 'did-add-panel', {panel, index}
     panel
 
+  panelForItem: (item) ->
+    for panel in @panels
+      return panel if panel.getItem() is item
+    null
+
   panelDestroyed: (panel) ->
     index = @panels.indexOf(panel)
     if index > -1

src/workspace.coffee

@@ -750,6 +750,16 @@ class Workspace extends Model
   addModalPanel: (options={}) ->
     @addPanel('modal', options)
 
+  # Essential: Returns the {Panel} associated with the given item. Returns
+  # `null` when the item has no panel.
+  #
+  # * `item` Item the panel contains
+  panelForItem: (item) ->
+    for location, container of @panelContainers
+      panel = container.panelForItem(item)
+      return panel if panel?
+    null
+
   getPanels: (location) ->
     @panelContainers[location].getPanels()