Merge pull request #2258 from atom/ns-react-scroll-perf

Improve scroll performance of the React editor

src/selection.coffee

@@ -563,6 +563,12 @@ class Selection extends Model
   intersectsBufferRange: (bufferRange) ->
     @getBufferRange().intersectsWith(bufferRange)
 
+  intersectsScreenRowRange: (startRow, endRow) ->
+    @getScreenRange().intersectsRowRange(startRow, endRow)
+
+  intersectsScreenRow: (screenRow) ->
+    @getScreenRange().intersectsRow(screenRow)
+
   # Public: Identifies if a selection intersects with another selection.
   #
   # otherSelection - A {Selection} to check against.
@@ -595,47 +601,6 @@ class Selection extends Model
   compare: (otherSelection) ->
     @getBufferRange().compare(otherSelection.getBufferRange())
 
-  # Get the pixel dimensions of rectangular regions that cover selection's area
-  # on the screen. Used by SelectionComponent for rendering.
-  getRegionRects: ->
-    lineHeight = @editor.getLineHeight()
-    {start, end} = @getScreenRange()
-    rowCount = end.row - start.row + 1
-    startPixelPosition = @editor.pixelPositionForScreenPosition(start)
-    endPixelPosition = @editor.pixelPositionForScreenPosition(end)
-
-    if rowCount is 1
-      # Single line selection
-      rects = [{
-        top: startPixelPosition.top
-        height: lineHeight
-        left: startPixelPosition.left
-        width: endPixelPosition.left - startPixelPosition.left
-      }]
-    else
-      # Multi-line selection
-      rects = []
-
-      # First row, extending from selection start to the right side of screen
-      rects.push {
-        top: startPixelPosition.top
-        left: startPixelPosition.left
-        height: lineHeight
-        right: 0
-      }
-      if rowCount > 2
-        # Middle rows, extending from left side to right side of screen
-        rects.push {
-          top: startPixelPosition.top + lineHeight
-          height: (rowCount - 2) * lineHeight
-          left: 0
-          right: 0
-        }
-      # Last row, extending from left side of screen to selection end
-      rects.push {top: endPixelPosition.top, height: lineHeight, left: 0, width: endPixelPosition.left }
-
-    rects
-
   screenRangeChanged: ->
     screenRange = @getScreenRange()
     @emit 'screen-range-changed', screenRange