Initial commit

input/input.go

@@ -0,0 +1,253 @@
+package input
+
+import "unicode"
+import "git.tebibyte.media/sashakoshka/stone"
+
+var selectedInput *Input
+
+func SelectNone () {
+	selectedInput = nil
+}
+
+type Input struct {
+	cursor int
+	text   []rune
+	X, Y, Width int
+	Obscure bool
+	OnDone func ()
+	OnCancel func ()
+}
+
+func (input *Input) HandleButton (button stone.Button, control, shift, alt bool) {
+	switch button {
+	case stone.KeyLeft:
+		if control {
+			input.cursor -= input.distanceToPreviousWordBound()
+		} else if alt {
+			input.cursorToBeginning()
+		} else {
+			input.cursor --
+		}
+		input.constrainCursor()
+		
+	case stone.KeyRight:
+		if control {
+			input.cursor += input.distanceToNextWordBound()
+		} else if alt {
+			input.cursorToEnd()
+		} else {
+			input.cursor ++
+		}
+		input.constrainCursor()
+		
+	case stone.KeyHome:
+		input.cursorToBeginning()
+		input.constrainCursor()
+		
+	case stone.KeyEnd:
+		input.cursorToEnd()
+		input.constrainCursor()
+	
+	case stone.KeyBackspace:
+		if control {
+			input.backspace(input.distanceToPreviousWordBound())
+		} else if alt {
+			input.backspace(input.cursor)
+		} else {
+			input.backspace(1)
+		}
+		input.constrainCursor()
+	
+	case stone.KeyDelete:
+		if control {
+			input.delete(input.distanceToNextWordBound())
+		} else if alt {
+			input.delete(len(input.text))
+		} else {
+			input.delete(1)
+		}
+		input.constrainCursor()
+
+	case stone.KeyEnter:
+		SelectNone()
+		if input.OnDone != nil {
+			input.OnDone()
+		}
+
+	case stone.KeyEscape:
+		SelectNone()
+		if input.OnCancel != nil {
+			input.OnCancel()
+		}
+	
+	default:
+		if button.Printable() {
+			input.text = append(input.text, 0)
+			copy (
+				input.text[input.cursor + 1:],
+				input.text[input.cursor:])
+			input.text[input.cursor] = rune(button)
+			input.cursor ++
+		}
+	}
+
+	return
+}
+
+func (input *Input) Draw (buffer stone.Buffer) {
+	buffer.SetRune(input.X, input.Y, '[')
+	buffer.SetRune(input.X + 1, input.Y, 0)
+	buffer.SetRune(input.X + input.Width - 2, input.Y, 0)
+	buffer.SetRune(input.X + input.Width - 1, input.Y, ']')
+
+	actualWidth := input.Width - 4
+	scroll := 0
+
+	x := input.X + 2
+	for index := 0; index < actualWidth; index ++ {
+		character := input.charAtSafe(index + scroll)
+
+		if input.Selected() && index == input.cursor {
+			buffer.SetRune(x, input.Y, '_')
+		} else if input.Obscure && character > 0 {
+			buffer.SetRune(x, input.Y, '*')
+		} else {
+			buffer.SetRune(x, input.Y, character)
+		}
+		x ++
+	}
+}
+
+func (input *Input) charAtSafe (index int) (character rune) {
+	if index <  0               { return }
+	if index >= len(input.text) { return }
+	character = input.text[index]
+	return
+}
+
+func (input *Input) constrainCursor () (constrained bool) {
+	if input.cursor < 0 {
+		input.cursorToBeginning()
+		constrained = true
+	} else if input.cursor > len(input.text) {
+		input.cursorToEnd()
+		constrained = true
+	}
+
+	return
+}
+
+func (input *Input) distanceToPreviousWordBound () (distance int) {
+	index := input.cursor
+	index    --
+	distance ++
+	
+	for {
+		if index < 0 { break }
+		
+		character := input.text[index]
+		isWordChar :=
+			unicode.IsLetter(character) ||
+			unicode.IsDigit(character)
+		if !isWordChar {
+			distance --
+			break
+		}
+		
+		distance ++
+		index --
+	}
+
+	if distance < 1 {
+		distance ++
+	}
+
+	return
+}
+
+func (input *Input) distanceToNextWordBound () (distance int) {
+	index := input.cursor
+	
+	for {
+		if index >= len(input.text) { break }
+		
+		character := input.text[index]
+		isWordChar :=
+			unicode.IsLetter(character) ||
+			unicode.IsDigit(character)
+		if !isWordChar {
+			break
+		}
+		
+		distance ++
+		index ++
+	}
+
+	if distance < 1 {
+		distance ++
+	}
+
+	return
+}
+
+func (input *Input) backspace (amount int) {
+	if input.cursor - amount < 0 {
+		amount = input.cursor
+	}
+		
+	copy (
+		input.text[input.cursor - amount:],
+		input.text[input.cursor:])
+	input.text = input.text[:len(input.text) - amount]
+	input.cursor -= amount
+}
+
+func (input *Input) delete (amount int) {
+	if input.cursor + amount > len(input.text) {
+		amount = len(input.text) - input.cursor
+	}
+
+	// TODO
+	copy (
+		input.text[input.cursor:],
+		input.text[input.cursor + amount:])
+	input.text = input.text[:len(input.text) - amount]
+}
+
+func (input *Input) cursorToBeginning () {
+	input.cursor = 0
+}
+
+func (input *Input) cursorToEnd () {
+	input.cursor = len(input.text)
+}
+
+func (input *Input) Reset () {
+	input.SetText("")
+}
+
+func (input *Input) Text () (text string) {
+	text = string(input.text)
+	return
+}
+
+func (input *Input) SetText (text string) {
+	input.text = []rune(text)
+	input.cursorToEnd()
+	return
+}
+
+func (input *Input) Selected () (selected bool) {
+	selected = selectedInput == input
+	return
+}
+
+func (input *Input) Select () () {
+	selectedInput = input
+	return
+}
+
+func Selected () (selected *Input) {
+	selected = selectedInput
+	return
+}