Very basic text input

artist/text.go

@@ -19,6 +19,7 @@ type wordLayout struct {
 	spaceAfter  int
 	breaksAfter int
 	text        []characterLayout
+	whitespace  []characterLayout
 }
 
 // Align specifies a text alignment method.
@@ -184,6 +185,32 @@ func (drawer *TextDrawer) ReccomendedHeightFor (width int) (height int) {
 	return dot.Y.Round()
 }
 
+// PositionOf returns the position of the character at the specified index
+// relative to the baseline.
+func (drawer *TextDrawer) PositionOf (index int) (position image.Point) {
+	if !drawer.layoutClean { drawer.recalculate() }
+	index ++
+	for _, word := range drawer.layout {
+		position = word.position
+		for _, character := range word.text {
+			index --
+			position.X = word.position.X + character.x
+			if index < 1 { return }
+		}
+		for _, character := range word.whitespace {
+			index --
+			position.X = word.position.X + character.x
+			if index < 1 { return }
+		}
+	}
+	return
+}
+
+// Length returns the amount of runes in the drawer's text.
+func (drawer *TextDrawer) Length () (length int) {
+	return len(drawer.runes)
+}
+
 func (drawer *TextDrawer) recalculate () {
 	drawer.layoutClean = true
 	drawer.layout = nil
@@ -194,7 +221,8 @@ func (drawer *TextDrawer) recalculate () {
 	metrics := drawer.face.Metrics()
 	dot := fixed.Point26_6 { 0, 0 }
 	index := 0
-	horizontalExtent := 0
+	horizontalExtent  := 0
+	currentCharacterX := fixed.Int26_6(0)
 
 	previousCharacter := rune(-1)
 	for index < len(drawer.runes) {
@@ -203,7 +231,7 @@ func (drawer *TextDrawer) recalculate () {
 		word.position.Y = dot.Y.Round()
 
 		// process a word
-		currentCharacterX := fixed.Int26_6(0)
+		currentCharacterX  = 0
 		wordWidth         := fixed.Int26_6(0)
 		for index < len(drawer.runes) && !unicode.IsSpace(drawer.runes[index]) {
 			character := drawer.runes[index]
@@ -243,31 +271,37 @@ func (drawer *TextDrawer) recalculate () {
 			dot.X = wordWidth
 		}
 
-		// skip over whitespace, going onto a new line if there is a
+		// process whitespace, going onto a new line if there is a
 		// newline character
+		spaceWidth := fixed.Int26_6(0)
 		for index < len(drawer.runes) && unicode.IsSpace(drawer.runes[index]) {
 			character := drawer.runes[index]
+			_, advance, ok := drawer.face.GlyphBounds(character)
+			index ++
+			if !ok { continue }
+			word.whitespace = append(word.whitespace, characterLayout {
+				x: currentCharacterX.Round(),
+				character: character,
+			})
+			spaceWidth        += advance
+			currentCharacterX += advance
+			
 			if character == '\n' {
 				dot.Y += metrics.Height
 				dot.X = 0
 				word.breaksAfter ++
-				previousCharacter = character
-				index ++
+				break
 			} else {
-				_, advance, ok := drawer.face.GlyphBounds(character)
-				word.spaceAfter = advance.Round()
-				index ++
-				if !ok { continue }
-				
 				dot.X += advance
 				if previousCharacter >= 0 {
 					dot.X += drawer.face.Kern (
 						previousCharacter,
 						character)
 				}
-				previousCharacter = character
 			}
+			previousCharacter = character
 		}
+		word.spaceAfter = spaceWidth.Round()
 
 		// add the word to the layout
 		drawer.layout = append(drawer.layout, word)
@@ -293,6 +327,16 @@ func (drawer *TextDrawer) recalculate () {
 		}
 	}
 
+	// add a little null to the last character
+	if len(drawer.layout) > 0 {
+		lastWord := &drawer.layout[len(drawer.layout) - 1]
+		lastWord.whitespace = append (
+			lastWord.whitespace,
+			characterLayout {
+				x: currentCharacterX.Round(),
+			})
+	}
+
 	if drawer.wrap {
 		drawer.layoutBounds.Max.X = drawer.width
 	} else {

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))
+		}
+	}
+}

examples/input/main.go

@@ -0,0 +1,34 @@
+package main
+
+import "git.tebibyte.media/sashakoshka/tomo"
+import "git.tebibyte.media/sashakoshka/tomo/layouts"
+import "git.tebibyte.media/sashakoshka/tomo/elements/basic"
+import _ "git.tebibyte.media/sashakoshka/tomo/backends/x"
+
+func main () {
+	tomo.Run(run)
+}
+
+func run () {
+	window, _ := tomo.NewWindow(2, 2)
+	window.SetTitle("Approaching")
+	container := basic.NewContainer(layouts.Vertical { true, true })
+	window.Adopt(container)
+
+	firstName    := basic.NewTextBox("First name", "")
+	lastName     := basic.NewTextBox("Last name", "")
+	fingerLength := basic.NewTextBox("Length of fingers", "")
+	button       := basic.NewButton("Ok")
+	
+	container.Adopt(basic.NewLabel("Choose your words carefully.", false), true)
+	container.Adopt(firstName, false)
+	container.Adopt(lastName, false)
+	container.Adopt(fingerLength, false)
+	container.Adopt(basic.NewSpacer(true), false)
+	container.Adopt(button, false)
+
+	firstName.Select()
+	
+	window.OnClose(tomo.Stop)
+	window.Show()
+}

theme/input.go

@@ -0,0 +1,33 @@
+package theme
+
+import "git.tebibyte.media/sashakoshka/tomo/artist"
+
+var inputPattern = artist.NewMultiBorder (
+	artist.Border { Weight: 1, Stroke: strokePattern },
+	artist.Border {
+		Weight: 1,
+		Stroke: artist.Chiseled {
+			Highlight: artist.NewUniform(hex(0x89925AFF)),
+			Shadow:    artist.NewUniform(hex(0xD2CB9AFF)),
+		},
+	},
+	artist.Border { Stroke: artist.NewUniform(hex(0xD2CB9AFF)) })
+var selectedInputPattern = artist.NewMultiBorder (
+	artist.Border { Weight: 1, Stroke: strokePattern },
+	artist.Border { Weight: 1, Stroke: accentPattern },
+	artist.Border { Stroke: artist.NewUniform(hex(0xD2CB9AFF)) })
+var disabledInputPattern = artist.NewMultiBorder (
+	artist.Border { Weight: 1, Stroke: weakForegroundPattern },
+	artist.Border { Stroke: backgroundPattern })
+
+func InputPattern (enabled, selected bool) (artist.Pattern) {
+	if enabled {
+		if selected {
+			return selectedInputPattern
+		} else {
+			return inputPattern
+		}
+	} else {
+		return disabledInputPattern
+	}
+}