onDidChangeSelectionRange emits object with ranges + selection

spec/editor-spec.coffee

@@ -901,6 +901,22 @@ describe "Editor", ->
     beforeEach ->
       selection = editor.getLastSelection()
 
+    describe "when the selection range changes", ->
+      it "emits an event with the old range, new range, and the selection that moved", ->
+        editor.setSelectedBufferRange([[3, 0], [4, 5]])
+
+        editor.onDidChangeSelectionRange rangeChangedHandler = jasmine.createSpy()
+        editor.selectToBufferPosition([6, 2])
+
+        expect(rangeChangedHandler).toHaveBeenCalled()
+        eventObject = rangeChangedHandler.mostRecentCall.args[0]
+
+        expect(eventObject.oldBufferRange).toEqual [[3, 0], [4, 5]]
+        expect(eventObject.oldScreenRange).toEqual [[3, 0], [4, 5]]
+        expect(eventObject.newBufferRange).toEqual [[3, 0], [6, 2]]
+        expect(eventObject.newScreenRange).toEqual [[3, 0], [6, 2]]
+        expect(eventObject.selection).toBe selection
+
     describe ".selectUp/Down/Left/Right()", ->
       it "expands each selection to its cursor's new location", ->
         editor.setSelectedBufferRanges([[[0,9], [0,13]], [[3,16], [3,21]]])

src/editor.coffee

@@ -2088,9 +2088,9 @@ class Editor extends Model
       false
 
   # Called by the selection
-  selectionRangeChanged: (selection) ->
-    @emit 'selection-screen-range-changed', selection
-    @emitter.emit 'did-change-selection-range', selection
+  selectionRangeChanged: (event) ->
+    @emit 'selection-screen-range-changed', event
+    @emitter.emit 'did-change-selection-range', event
 
   ###
   Section: Searching and Replacing

src/selection.coffee

@@ -21,7 +21,7 @@ class Selection extends Model
     @cursor.selection = this
     @decoration = @editor.decorateMarker(@marker, type: 'highlight', class: 'selection')
 
-    @marker.onDidChange => @screenRangeChanged()
+    @marker.onDidChange (e) => @screenRangeChanged(e)
     @marker.onDidDestroy =>
       unless @editor.isDestroyed()
         @destroyed = true
@@ -686,10 +686,20 @@ class Selection extends Model
   Section: Private Utilities
   ###
 
-  screenRangeChanged: ->
-    @emit 'screen-range-changed', @getScreenRange()
+  screenRangeChanged: (e) ->
+    {oldHeadBufferPosition, oldTailBufferPosition} = e
+    {oldHeadScreenPosition, oldTailScreenPosition} = e
+
+    eventObject =
+      oldBufferRange: new Range(oldHeadBufferPosition, oldTailBufferPosition)
+      oldScreenRange: new Range(oldHeadScreenPosition, oldTailScreenPosition)
+      newBufferRange: @getBufferRange()
+      newScreenRange: @getScreenRange()
+      selection: this
+
+    @emit 'screen-range-changed', @getScreenRange() # old event
     @emitter.emit 'did-change-range'
-    @editor.selectionRangeChanged(this)
+    @editor.selectionRangeChanged(eventObject)
 
   finalize: ->
     @initialScreenRange = null unless @initialScreenRange?.isEqual(@getScreenRange())