Cursor improvements

cmd/micro/buffer/cursor.go

@@ -48,7 +48,7 @@ func (c *Cursor) Goto(b Cursor) {
 // the current cursor its selection too
 func (c *Cursor) GotoLoc(l Loc) {
 	c.X, c.Y = l.X, l.Y
-	c.LastVisualX = c.GetVisualX()
+	c.StoreVisualX()
 }
 
 // GetVisualX returns the x value of the cursor in visual spaces
@@ -89,11 +89,13 @@ func (c *Cursor) GetCharPosInLine(b []byte, visualPos int) int {
 			width += runewidth.RuneWidth(r)
 		}
 
-		i++
-
 		if width >= visualPos {
+			if width == visualPos {
+				i++
+			}
 			break
 		}
+		i++
 	}
 
 	return i
@@ -155,6 +157,21 @@ func (c *Cursor) DeleteSelection() {
 	}
 }
 
+// Deselect closes the cursor's current selection
+// Start indicates whether the cursor should be placed
+// at the start or end of the selection
+func (c *Cursor) Deselect(start bool) {
+	if c.HasSelection() {
+		if start {
+			c.Loc = c.CurSelection[0]
+		} else {
+			c.Loc = c.CurSelection[1]
+		}
+		c.ResetSelection()
+		c.StoreVisualX()
+	}
+}
+
 // GetSelection returns the cursor's selection
 func (c *Cursor) GetSelection() []byte {
 	if InBounds(c.CurSelection[0], c.Buf) && InBounds(c.CurSelection[1], c.Buf) {
@@ -244,7 +261,7 @@ func (c *Cursor) Left() {
 		c.Up()
 		c.End()
 	}
-	c.LastVisualX = c.GetVisualX()
+	c.StoreVisualX()
 }
 
 // Right moves the cursor right one cell (if possible) or
@@ -259,7 +276,7 @@ func (c *Cursor) Right() {
 		c.Down()
 		c.Start()
 	}
-	c.LastVisualX = c.GetVisualX()
+	c.StoreVisualX()
 }
 
 // Relocate makes sure that the cursor is inside the bounds
@@ -278,3 +295,7 @@ func (c *Cursor) Relocate() {
 		c.X = utf8.RuneCount(c.Buf.LineBytes(c.Y))
 	}
 }
+
+func (c *Cursor) StoreVisualX() {
+	c.LastVisualX = c.GetVisualX()
+}