Merge pull request #18087 from atom/aw/gutter-measurement-update

Update soft wrap margins on gutter re-measurement

spec/text-editor-component-spec.js

@@ -2085,6 +2085,26 @@ describe('TextEditorComponent', () => {
       const bLabels = Array.from(bNumbers, e => e.textContent)
       expect(bLabels).toEqual(['b - 0', 'b - 1', 'b - 2', 'b - 3', 'b - 4', 'b - 5'])
     })
+
+    it("updates the editor's soft wrap width when a custom gutter's measurement is available", () => {
+      const {component, element, editor} = buildComponent({
+        lineNumberGutterVisible: false,
+        width: 400,
+        softWrapped: true,
+        attach: false,
+      })
+      const gutter = editor.addGutter({name: 'a', priority: 10})
+      gutter.getElement().style.width = '100px'
+
+      jasmine.attachToDOM(element)
+
+      expect(component.getGutterContainerWidth()).toBe(100)
+
+      // Component client width - gutter container width - vertical scrollbar width
+      const softWrapColumn = Math.floor(
+        (400 - 100 - component.getVerticalScrollbarWidth()) / component.getBaseCharacterWidth())
+      expect(editor.getSoftWrapColumn()).toBe(softWrapColumn)
+    })
   })
 
   describe('block decorations', () => {

src/text-editor-component.js

@@ -387,8 +387,9 @@ class TextEditorComponent {
   }
 
   measureContentDuringUpdateSync () {
+    let gutterDimensionsChanged = false
     if (this.remeasureGutterDimensions) {
-      this.measureGutterDimensions()
+      gutterDimensionsChanged = this.measureGutterDimensions()
       this.remeasureGutterDimensions = false
     }
     const wasHorizontalScrollbarVisible = (
@@ -419,7 +420,7 @@ class TextEditorComponent {
     this.linesToMeasure.clear()
     this.measuredContent = true
 
-    return wasHorizontalScrollbarVisible !== isHorizontalScrollbarVisible
+    return gutterDimensionsChanged || wasHorizontalScrollbarVisible !== isHorizontalScrollbarVisible
   }
 
   updateSyncAfterMeasuringContent () {