🐎 Avoid to measure invisible lines when dragging

spec/lines-yardstick-spec.coffee

@@ -44,8 +44,7 @@ describe "LinesYardstick", ->
       mockLineNodesProvider =
         updateSync: (state) -> availableScreenRows = state
         lineNodeForLineIdAndScreenRow: (lineId, screenRow) ->
-          if availableScreenRows[lineId] isnt screenRow
-            throw new Error("No line node found!")
+          return if availableScreenRows[lineId] isnt screenRow
 
           buildLineNode(screenRow)
 
@@ -120,6 +119,18 @@ describe "LinesYardstick", ->
       expect(linesYardstick.pixelPositionForScreenPosition([0, 9]).left).toBe 67
       expect(linesYardstick.pixelPositionForScreenPosition([0, 11]).left).toBe 84
 
+    it "doesn't measure invisible lines if it is explicitly told so", ->
+      atom.styles.addStyleSheet """
+      * {
+        font-size: 12px;
+        font-family: monospace;
+      }
+      """
+
+      expect(linesYardstick.pixelPositionForScreenPosition([0, 0], true, true)).toEqual({left: 0, top: 0})
+      expect(linesYardstick.pixelPositionForScreenPosition([0, 1], true, true)).toEqual({left: 0, top: 0})
+      expect(linesYardstick.pixelPositionForScreenPosition([0, 5], true, true)).toEqual({left: 0, top: 0})
+
     describe "::screenPositionForPixelPosition(pixelPosition)", ->
       it "converts pixel positions to screen positions", ->
         atom.styles.addStyleSheet """
@@ -152,3 +163,15 @@ describe "LinesYardstick", ->
         expect(linesYardstick.screenPositionForPixelPosition(top: Infinity, left: Infinity)).toEqual [12, 2]
         expect(linesYardstick.screenPositionForPixelPosition(top: (editor.getLastScreenRow() + 1) * 14, left: 0)).toEqual [12, 2]
         expect(linesYardstick.screenPositionForPixelPosition(top: editor.getLastScreenRow() * 14, left: 0)).toEqual [12, 0]
+
+      it "doesn't measure invisible lines if it is explicitly told so", ->
+        atom.styles.addStyleSheet """
+        * {
+          font-size: 12px;
+          font-family: monospace;
+        }
+        """
+
+        expect(linesYardstick.screenPositionForPixelPosition({top: 0, left: 13}, true)).toEqual([0, 0])
+        expect(linesYardstick.screenPositionForPixelPosition({top: 14, left: 20}, true)).toEqual([1, 0])
+        expect(linesYardstick.screenPositionForPixelPosition({top: 28, left: 100}, true)).toEqual([2, 0])

src/lines-yardstick.coffee

@@ -20,7 +20,7 @@ class LinesYardstick
   clearScreenRowsForMeasurement: ->
     @presenter.clearScreenRowsToMeasure()
 
-  screenPositionForPixelPosition: (pixelPosition) ->
+  screenPositionForPixelPosition: (pixelPosition, measureVisibleLinesOnly) ->
     targetTop = pixelPosition.top
     targetLeft = pixelPosition.left
     defaultCharWidth = @model.getDefaultCharWidth()
@@ -30,7 +30,7 @@ class LinesYardstick
     row = Math.min(row, @model.getLastScreenRow())
     row = Math.max(0, row)
 
-    @prepareScreenRowsForMeasurement([row])
+    @prepareScreenRowsForMeasurement([row]) unless measureVisibleLinesOnly
 
     line = @model.tokenizedLineForScreenRow(row)
     lineNode = @lineNodesProvider.lineNodeForLineIdAndScreenRow(line?.id, row)
@@ -78,26 +78,26 @@ class LinesYardstick
         previousColumn = column
         column += charLength
 
-    @clearScreenRowsForMeasurement()
+    @clearScreenRowsForMeasurement() unless measureVisibleLinesOnly
 
     if targetLeft <= previousLeft + (charWidth / 2)
       new Point(row, previousColumn)
     else
       new Point(row, column)
 
-  pixelPositionForScreenPosition: (screenPosition, clip=true) ->
+  pixelPositionForScreenPosition: (screenPosition, clip=true, measureVisibleLinesOnly) ->
     screenPosition = Point.fromObject(screenPosition)
     screenPosition = @model.clipScreenPosition(screenPosition) if clip
 
     targetRow = screenPosition.row
     targetColumn = screenPosition.column
 
-    @prepareScreenRowsForMeasurement([targetRow])
+    @prepareScreenRowsForMeasurement([targetRow]) unless measureVisibleLinesOnly
 
     top = targetRow * @model.getLineHeightInPixels()
     left = @leftPixelPositionForScreenPosition(targetRow, targetColumn)
 
-    @clearScreenRowsForMeasurement()
+    @clearScreenRowsForMeasurement() unless measureVisibleLinesOnly
 
     {top, left}
 

src/text-editor-component.coffee

@@ -423,14 +423,14 @@ class TextEditorComponent
   getVisibleRowRange: ->
     @presenter.getVisibleRowRange()
 
-  pixelPositionForScreenPosition: (screenPosition) ->
-    @linesYardstick.pixelPositionForScreenPosition(screenPosition)
+  pixelPositionForScreenPosition: ->
+    @linesYardstick.pixelPositionForScreenPosition(arguments...)
 
-  screenPositionForPixelPosition: (pixelPosition) ->
-    @linesYardstick.screenPositionForPixelPosition(pixelPosition)
+  screenPositionForPixelPosition: ->
+    @linesYardstick.screenPositionForPixelPosition(arguments...)
 
-  pixelRectForScreenRange: (screenRange) ->
-    @linesYardstick.pixelRectForScreenRange(screenRange)
+  pixelRectForScreenRange: ->
+    @linesYardstick.pixelRectForScreenRange(arguments...)
 
   pixelRangeForScreenRange: (screenRange, clip=true) ->
     {start, end} = Range.fromObject(screenRange)
@@ -850,7 +850,7 @@ class TextEditorComponent
 
   screenPositionForMouseEvent: (event, linesClientRect) ->
     pixelPosition = @pixelPositionForMouseEvent(event, linesClientRect)
-    @screenPositionForPixelPosition(pixelPosition)
+    @screenPositionForPixelPosition(pixelPosition, true)
 
   pixelPositionForMouseEvent: (event, linesClientRect) ->
     {clientX, clientY} = event