Emit 'marker-added/removed' when buffer markers are created/destroyed

spec/app/text-buffer-spec.coffee

@@ -781,6 +781,12 @@ describe 'Buffer', ->
         expect(buffer.positionForCharacterIndex(20)).toEqual [3, 0]
 
   describe "markers", ->
+    [markerAddedHandler, markerRemovedHandler] = []
+
+    beforeEach ->
+      buffer.on('marker-added', markerAddedHandler = jasmine.createSpy("markerAddedHandler"))
+      buffer.on('marker-removed', markerRemovedHandler = jasmine.createSpy("markerRemovedHandler"))
+
     describe "marker creation", ->
       it "allows markers to be created with ranges and positions", ->
         marker1 = buffer.markRange([[4, 20], [4, 23]])
@@ -800,6 +806,10 @@ describe 'Buffer', ->
         expect(marker.getHeadPosition()).toEqual [4, 20]
         expect(marker.getTailPosition()).toEqual [4, 23]
 
+      it "emits the 'marker-added' event when markers are created", ->
+        marker = buffer.markRange([[4, 20], [4, 23]])
+        expect(markerAddedHandler).toHaveBeenCalledWith(marker)
+
     describe "marker manipulation", ->
       marker = null
       beforeEach ->
@@ -995,6 +1005,10 @@ describe 'Buffer', ->
         buffer.undo()
         expect(buffer.getMarker(marker2.id)).toBeUndefined()
 
+      it "emits 'marker-removed' when markers are destroyed", ->
+        marker.destroy()
+        expect(markerRemovedHandler).toHaveBeenCalledWith(marker)
+
     describe "marker updates due to buffer changes", ->
       [marker1, marker2, marker3] = []
 

src/app/text-buffer.coffee

@@ -476,6 +476,8 @@ class Buffer
       attributes
     }, options))
     @validMarkers[marker.id] = marker
+    @trigger 'marker-added', marker
+    marker
 
   # Public: Constructs a new marker at a given position.
   #
@@ -645,8 +647,10 @@ class Buffer
   ###
 
   destroyMarker: (id) ->
-    delete @validMarkers[id]
-    delete @invalidMarkers[id]
+    if marker = @validMarkers[id] ? @invalidMarkers[id]
+      delete @validMarkers[id]
+      delete @invalidMarkers[id]
+      @trigger 'marker-removed', marker
 
   scheduleModifiedEvents: ->
     clearTimeout(@stoppedChangingTimeout) if @stoppedChangingTimeout