Improve cursor drawing

SwiftNeoVim/Grid.swift

@@ -174,6 +174,18 @@ class Grid: CustomStringConvertible {
     self.cells[position.row][position.column].marked = false
   }
 
+  func isNextCellEmpty(position: Position) -> Bool {
+    if self.cells[position.row][min(position.column + 1, self.size.width - 1)].string.characters.count == 0 {
+      return true
+    }
+
+    return false
+  }
+
+  func nextCellPosition(position: Position) -> Position {
+    return Position(row: position.row, column: min(position.column + 1, self.size.width - 1))
+  }
+
   private func clearRegion(region: Region) {
     // FIXME: sometimes clearRegion gets called without first resizing the Grid. Should we handle this?
     guard self.hasData else {

SwiftNeoVim/NeoVimView.swift

@@ -143,12 +143,9 @@ public class NeoVimView: NSView {
 //    Swift.print("\(#function): \(cursorPosition)")
 
     var cursorRect = self.cellRect(row: cursorPosition.row, column: cursorPosition.column)
-    Swift.print("@@@@@@@@@@@@@@@@@ original \(cursorRect)")
-    let nextColumn = min(cursorPosition.column + 1, self.grid.size.width)
-    let nextString = self.grid.cells[cursorPosition.row][nextColumn].string
-    if nextString.characters.count == 0 {
-      cursorRect = cursorRect.union(self.cellRect(row: cursorPosition.row, column:nextColumn))
-      Swift.print("@@@@@@@@@@@@@@@@@ new \(cursorRect)")
+    if self.grid.isNextCellEmpty(cursorPosition) {
+      let nextPosition = self.grid.nextCellPosition(cursorPosition)
+      cursorRect = cursorRect.union(self.cellRect(row: nextPosition.row, column:nextPosition.column))
     }
 
     ColorUtils.colorFromCodeIgnoringAlpha(background).set()

SwiftNeoVim/NeoVimViewUiBridge.swift

@@ -46,11 +46,9 @@ extension NeoVimView: NeoVimUiBridgeProtocol {
   public func cursorGotoRow(row: Int32, column: Int32) {
     DispatchUtils.gui {
       Swift.print("### goto: \(row):\(column)")
-      self.setNeedsDisplayAt(position: self.grid.position)
-
-      let newPosition = Position(row: Int(row), column: Int(column))
-      self.grid.goto(newPosition)
-      self.setNeedsDisplayAt(position: newPosition)
+      self.setCursorNeedsDisplay()
+      self.grid.goto(Position(row: Int(row), column: Int(column)))
+      self.setCursorNeedsDisplay()
     }
   }
   
@@ -113,7 +111,15 @@ extension NeoVimView: NeoVimUiBridgeProtocol {
       if string.characters.count == 0 {
         self.setNeedsDisplayAt(row: curPos.row, column: max(curPos.column - 1, 0))
       }
-      self.setNeedsDisplayAt(position: self.grid.position) // cursor
+      self.setCursorNeedsDisplay()
+    }
+  }
+
+  private func setCursorNeedsDisplay() {
+    let position = self.grid.position
+    self.setNeedsDisplayAt(position: position)
+    if self.grid.isNextCellEmpty(position) {
+      self.setNeedsDisplayAt(position: self.grid.nextCellPosition(position))
     }
   }
 
@@ -127,7 +133,7 @@ extension NeoVimView: NeoVimUiBridgeProtocol {
       if markedText.characters.count == 0 {
         self.setNeedsDisplayAt(row: curPos.row, column: max(curPos.column - 1, 0))
       }
-      self.setNeedsDisplayAt(position: self.grid.position) // cursor
+      self.setCursorNeedsDisplay()
     }
   }
 
@@ -136,7 +142,7 @@ extension NeoVimView: NeoVimUiBridgeProtocol {
 //      Swift.print("\(#function): \(row):\(column)")
       self.grid.unmarkCell(Position(row: Int(row), column: Int(column)))
       self.setNeedsDisplayAt(row: Int(row), column: Int(column))
-      self.setNeedsDisplayAt(position: self.grid.position) // cursor
+      self.setCursorNeedsDisplay()
     }
   }