Merge pull request #1078 from atom/ks-soft-wrap-resize

Update soft wrap column on editor resize

spec/editor-spec.coffee

@@ -1656,6 +1656,7 @@ describe "Editor", ->
 
   describe "when soft-wrap is enabled", ->
     beforeEach ->
+      jasmine.unspy(window, 'setTimeout')
       editSession.setSoftWrap(true)
       editor.attachToDom()
       setEditorHeightInLines(editor, 20)
@@ -1735,6 +1736,19 @@ describe "Editor", ->
       expect(otherEditor.setWidthInChars).toHaveBeenCalled()
       otherEditor.remove()
 
+    describe "when the editor's width changes", ->
+      it "updates the width in characters on the edit session", ->
+        previousSoftWrapColumn = editSession.getSoftWrapColumn()
+
+        spyOn(editor, 'setWidthInChars').andCallThrough()
+        editor.width(editor.width() / 2)
+
+        waitsFor ->
+          editor.setWidthInChars.callCount > 0
+
+        runs ->
+          expect(editSession.getSoftWrapColumn()).toBeLessThan previousSoftWrapColumn
+
   describe "gutter rendering", ->
     beforeEach ->
       editor.attachToDom(heightInLines: 5.5)

src/display-buffer.coffee

@@ -106,8 +106,10 @@ class DisplayBuffer
   #
   # editorWidthInChars - A {Number} of characters.
   setEditorWidthInChars: (editorWidthInChars) ->
+    previousWidthInChars = @state.get('editorWidthInChars')
     @state.set('editorWidthInChars', editorWidthInChars)
-    @updateWrappedScreenLines() if @getSoftWrap()
+    if editorWidthInChars isnt previousWidthInChars and @getSoftWrap()
+      @updateWrappedScreenLines()
 
   getSoftWrapColumn: ->
     editorWidthInChars = @state.get('editorWidthInChars')

src/editor.coffee

@@ -704,6 +704,12 @@ class Editor extends View
       else
         @gutter.addClass('drop-shadow')
 
+    # Listen for overflow events to detect when the editor's width changes
+    # to update the soft wrap column.
+    updateWidthInChars = _.debounce((=> @setWidthInChars()), 100)
+    @scrollView.on 'overflowchanged', =>
+      updateWidthInChars() if @[0].classList.contains('soft-wrap')
+
   handleInputEvents: ->
     @on 'cursor:moved', =>
       return unless @isFocused