Very basic text input

elements/basic/textbox.go

@@ -0,0 +1,202 @@
+package basic
+
+import "image"
+import "git.tebibyte.media/sashakoshka/tomo"
+import "git.tebibyte.media/sashakoshka/tomo/theme"
+import "git.tebibyte.media/sashakoshka/tomo/artist"
+import "git.tebibyte.media/sashakoshka/tomo/elements/core"
+
+type TextBox struct {
+	*core.Core
+	core core.CoreControl
+	
+	enabled  bool
+	selected bool
+
+	cursor int
+	placeholder string
+	text        string
+	placeholderDrawer artist.TextDrawer
+	valueDrawer       artist.TextDrawer
+}
+
+func NewTextBox (placeholder, text string) (element *TextBox) {
+	element = &TextBox { enabled: true }
+	element.Core, element.core = core.NewCore(element)
+	element.placeholderDrawer.SetFace(theme.FontFaceRegular())
+	element.valueDrawer.SetFace(theme.FontFaceRegular())
+	element.placeholder = placeholder
+	element.placeholderDrawer.SetText(placeholder)
+	element.updateMinimumSize()
+	element.SetText(text)
+	return
+}
+
+func (element *TextBox) Resize (width, height int) {
+	element.core.AllocateCanvas(width, height)
+	element.draw()
+}
+
+func (element *TextBox) HandleMouseDown (x, y int, button tomo.Button) {
+	element.Select()
+}
+
+func (element *TextBox) HandleMouseUp (x, y int, button tomo.Button) { }
+func (element *TextBox) HandleMouseMove (x, y int) { }
+func (element *TextBox) HandleScroll (x, y int, deltaX, deltaY float64) { }
+
+func (element *TextBox) HandleKeyDown (
+	key tomo.Key,
+	modifiers tomo.Modifiers,
+	repeated bool,
+) {
+	switch {
+	case key == tomo.KeyBackspace:
+		if len(element.text) < 1 { break }
+		element.cursor --
+		element.SetText(element.text[:len(element.text) - 1])
+	case key.Printable():
+		element.cursor ++
+		element.SetText(element.text + string(rune(key)))
+	}
+}
+
+func (element *TextBox) HandleKeyUp(key tomo.Key, modifiers tomo.Modifiers) { }
+
+func (element *TextBox) Selected () (selected bool) {
+	return element.selected
+}
+
+func (element *TextBox) Select () {
+	element.core.RequestSelection()
+}
+
+func (element *TextBox) HandleSelection (
+	direction tomo.SelectionDirection,
+) (
+	accepted bool,
+) {
+	direction = direction.Canon()
+	if !element.enabled { return false }
+	if element.selected && direction != tomo.SelectionDirectionNeutral {
+		return false
+	}
+	
+	element.selected = true
+	if element.core.HasImage() {
+		element.draw()
+		element.core.PushAll()
+	}
+	return true
+}
+
+func (element *TextBox) HandleDeselection () {
+	element.selected = false
+	if element.core.HasImage() {
+		element.draw()
+		element.core.PushAll()
+	}
+}
+
+func (element *TextBox) SetEnabled (enabled bool) {
+	if element.enabled == enabled { return }
+	element.enabled = enabled
+	if element.core.HasImage () {
+		element.draw()
+		element.core.PushAll()
+	}
+}
+
+func (element *TextBox) SetPlaceholder (placeholder string) {
+	if element.placeholder == placeholder { return }
+	
+	element.placeholder = placeholder
+	element.placeholderDrawer.SetText(placeholder)
+	
+	element.updateMinimumSize()
+	if element.core.HasImage () {
+		element.draw()
+		element.core.PushAll()
+	}
+}
+
+func (element *TextBox) updateMinimumSize () {
+	textBounds := element.placeholderDrawer.LayoutBounds()
+	element.core.SetMinimumSize (
+		textBounds.Dx() +
+		theme.Padding() * 2,
+		element.placeholderDrawer.LineHeight().Round() +
+		theme.Padding() * 2)
+}
+
+func (element *TextBox) SetText (text string) {
+	if element.text == text { return }
+
+	element.text = text
+	element.valueDrawer.SetText(text)
+	if element.cursor > element.valueDrawer.Length() {
+		element.cursor = element.valueDrawer.Length()
+	}
+	
+	if element.core.HasImage () {
+		element.draw()
+		element.core.PushAll()
+	}
+}
+
+func (element *TextBox) draw () {
+	bounds := element.core.Bounds()
+
+	artist.FillRectangle (
+		element.core,
+		theme.InputPattern (
+			element.enabled,
+			element.Selected()),
+		bounds)
+		
+	innerBounds := bounds
+	innerBounds.Min.X += theme.Padding()
+	innerBounds.Min.Y += theme.Padding()
+	innerBounds.Max.X -= theme.Padding()
+	innerBounds.Max.Y -= theme.Padding()
+
+	if element.text == "" && !element.selected {
+		// draw placeholder
+		textBounds := element.placeholderDrawer.LayoutBounds()
+		offset := image.Point {
+			X: theme.Padding(),
+			Y: theme.Padding(),
+		}
+		foreground := theme.ForegroundPattern(false)
+		element.placeholderDrawer.Draw (
+			element.core,
+			foreground,
+			offset.Sub(textBounds.Min))
+	} else {
+		// draw input value
+		textBounds := element.valueDrawer.LayoutBounds()
+		offset := image.Point {
+			X: theme.Padding(),
+			Y: theme.Padding(),
+		}
+		foreground := theme.ForegroundPattern(element.enabled)
+		element.valueDrawer.Draw (
+			element.core,
+			foreground,
+			offset.Sub(textBounds.Min))
+
+		if element.selected {
+			// cursor
+			cursorPosition := element.valueDrawer.PositionOf (
+				element.cursor)
+			artist.Line (
+				element.core,
+				theme.ForegroundPattern(true), 1,
+				cursorPosition.Add(offset),
+				image.Pt (
+					cursorPosition.X,
+					cursorPosition.Y + element.valueDrawer.
+					LineHeight().Round()).Add(offset))
+		}
+	}
+}