Add a very basic selection mode

filter.go

@@ -38,6 +38,13 @@ var highlight tcell.Style
 var selectedStyle tcell.Style
 var helpStyle tcell.Style
 
+type State struct {
+	Current         int
+	InSelectionMode bool
+	UpperBound      int
+	LowerBound      int
+}
+
 // Draws the given `text` to the screen `s` at the given coordinates. Remember that
 // the text will be wrapped if it overflow.
 func drawText(s tcell.Screen, x1, y1, x2, y2 int, style tcell.Style, text string) {
@@ -135,6 +142,8 @@ func main() {
 
 	lowerBound := 0
 	upperBound := min(ymax-3, len(*input))
+	inSelectedMode := false
+	startOfSelection := 0
 
 	// Event loop
 	for !done {
@@ -189,7 +198,13 @@ func main() {
 				upperBound = ymax - 2
 				lowerBound = 0
 				currentLine = 0
-
+			} else if ev.Key() == tcell.KeyCtrlSpace {
+				if inSelectedMode {
+					toggleItems(input, startOfSelection, currentLine)
+				} else {
+					startOfSelection = currentLine
+				}
+				inSelectedMode = !inSelectedMode
 			}
 		}
 	}

utils.go

@@ -36,6 +36,12 @@ func NewItem(text string) *Item {
 	}
 }
 
+func toggleItems(items Items, start int, end int) {
+	for _, item := range (*items)[start:end] {
+		item.Selected = !item.Selected
+	}
+}
+
 // Pffff Golang, right? :D
 func min(a, b int) int {
 	if a < b {