keys: Implement yank (C-y)

1 files changed, 21 insertions, 4 deletions

diff --git a/up.go b/up.go
index 3900df8..89e7fb5 100644
--- a/up.go
+++ b/up.go
@@ -283,9 +283,10 @@ func NewEditor(prompt string) *Editor {
 
 type Editor struct {
 	// TODO: make editor multiline. Reuse gocui or something for this?
-	prompt []rune
-	value  []rune
-	cursor int
+	prompt    []rune
+	value     []rune
+	killspace []rune
+	cursor    int
 	// lastw is length of value on last Draw; we need it to know how much to erase after backspace
 	lastw int
 }
@@ -341,7 +342,9 @@ func (e *Editor) HandleKey(ev *tcell.EventKey) bool {
 	case ctrlKey(tcell.KeyCtrlE):
 		e.cursor = e.lastw
 	case ctrlKey(tcell.KeyCtrlK):
-		e.value = e.value[:e.cursor]
+		e.kill()
+	case ctrlKey(tcell.KeyCtrlY):
+		e.yank()
 	default:
 		// Unknown key/combination, not handled
 		return false
@@ -366,6 +369,20 @@ func (e *Editor) delete(dx int) {
 	e.cursor = pos
 }
 
+func (e *Editor) kill() {
+	e.killspace = e.value[e.cursor:]
+	e.value = e.value[:e.cursor]
+}
+
+func (e *Editor) yank() {
+	if len(e.killspace) == 0 {
+		return
+	}
+	for _, r := range e.killspace {
+		e.insert(r)
+	}
+}
+
 type BufView struct {
 	// TODO: Wrap bool
 	Y   int // Y of the view in the Buf, for down/up scrolling