Selections are only cleared when cursor is explicitly moved

This allows multiple selections to be modified without changes to an earlier selection clearing later selections. It means we can remove the `modifySelections` method from `CompositeSelection` and just call methods on selections in a loop.

spec/atom/editor-spec.coffee

@@ -1893,4 +1893,4 @@ describe "Editor", ->
 
       eventHandler.reset()
       editor.buffer.setPath("new.txt")
-      expect(eventHandler).toHaveBeenCalled()
+      expect(eventHandler).toHaveBeenCalled()

src/atom/composite-cursor.coffee

@@ -21,7 +21,6 @@ class CompositeCursor
     cursor = new Cursor(@editor)
     @cursors.push(cursor)
     @editor.lines.append(cursor)
-    @editor.addSelectionForCursor(cursor)
     cursor
 
   addCursorAtScreenPosition: (screenPosition) ->

src/atom/composite-selection.coffee

@@ -35,6 +35,7 @@ class CompositeSeleciton
     selection = new Selection({@editor, cursor})
     @selections.push(selection)
     @editor.lines.append(selection)
+    selection
 
   addSelectionForBufferRange: (bufferRange, options) ->
     cursor = @editor.compositeCursor.addCursor()
@@ -66,26 +67,20 @@ class CompositeSeleciton
     fn(selection) for selection in @getSelections()
     @mergeIntersectingSelections(reverse: true)
 
-  modifySelectedText: (fn) ->
-    selection.retainSelection = true for selection in @getSelections()
-    for selection in @getSelections()
-      selection.retainSelection = false
-      fn(selection)
-
   insertText: (text) ->
-    @modifySelectedText (selection) -> selection.insertText(text)
+    selection.insertText(text) for selection in @getSelections()
 
   backspace: ->
-    @modifySelectedText (selection) -> selection.backspace()
+    selection.backspace() for selection in @getSelections()
 
   backspaceToBeginningOfWord: ->
-    @modifySelectedText (selection) -> selection.backspaceToBeginningOfWord()
+    selection.backspaceToBeginningOfWord() for selection in @getSelections()
 
   delete: ->
-    @modifySelectedText (selection) -> selection.delete()
+    selection.delete() for selection in @getSelections()
 
   deleteToEndOfWord: ->
-    @modifySelectedText (selection) -> selection.deleteToEndOfWord()
+    selection.deleteToEndOfWord() for selection in @getSelections()
 
   selectToScreenPosition: (position) ->
     @getLastSelection().selectToScreenPosition(position)
@@ -122,7 +117,7 @@ class CompositeSeleciton
 
   cut: ->
     maintainPasteboard = false
-    @modifySelectedText (selection) ->
+    for selection in @getSelections()
       selection.cut(maintainPasteboard)
       maintainPasteboard = true
 
@@ -140,4 +135,4 @@ class CompositeSeleciton
         if selection.intersectsWith(otherSelection)
           selection.merge(otherSelection, options)
           @mergeIntersectingSelections(options)
-          return
+          return

src/atom/cursor.coffee

@@ -14,6 +14,7 @@ class Cursor extends View
 
   initialize: (@editor) ->
     @anchor = new Anchor(@editor)
+    @selection = @editor.compositeSelection.addSelectionForCursor(this)
     @one 'attach', => @updateAppearance()
 
   handleBufferChange: (e) ->
@@ -31,6 +32,7 @@ class Cursor extends View
   setBufferPosition: (bufferPosition) ->
     @anchor.setBufferPosition(bufferPosition)
     @refreshScreenPosition()
+    @clearSelection()
 
   getScreenPosition: ->
     @anchor.getScreenPosition()
@@ -38,6 +40,7 @@ class Cursor extends View
   setScreenPosition: (position, options={}) ->
     @anchor.setScreenPosition(position, options)
     @refreshScreenPosition(position, options)
+    @clearSelection()
 
   refreshScreenPosition: ->
     @goalColumn = null
@@ -48,6 +51,9 @@ class Cursor extends View
     window.clearTimeout(@idleTimeout) if @idleTimeout
     @idleTimeout = window.setTimeout (=> @addClass 'idle'), 200
 
+  clearSelection: ->
+    @selection.clearSelection() unless @selection.retainSelection
+
   getCurrentBufferLine: ->
     @editor.lineForBufferRow(@getBufferPosition().row)
 

src/atom/selection.coffee

@@ -16,11 +16,7 @@ class Selection extends View
 
   initialize: ({@editor, @cursor}) ->
     @regions = []
-    @cursor.on 'cursor:position-changed', =>
-      if @retainSelection
-        @updateAppearance()
-      else
-        @clearSelection()
+    @cursor.on 'cursor:position-changed', => @updateAppearance()
 
   handleBufferChange: (e) ->
     return unless @anchor
@@ -106,6 +102,7 @@ class Selection extends View
     { text, shouldOutdent } = @autoIndentText(text)
     @editor.buffer.change(@getBufferRange(), text)
     @autoOutdentText() if shouldOutdent
+    @clearSelection()
 
   autoIndentText: (text) ->
     if @editor.autoIndent