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tomo-old/elements/basic/textbox.go

372 lines
9.2 KiB
Go

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/textmanip"
import "git.tebibyte.media/sashakoshka/tomo/elements/core"
// TextBox is a single-line text input.
type TextBox struct {
*core.Core
core core.CoreControl
enabled bool
selected bool
cursor int
scroll int
placeholder string
text []rune
placeholderDrawer artist.TextDrawer
valueDrawer artist.TextDrawer
onKeyDown func (key tomo.Key, modifiers tomo.Modifiers) (handled bool)
onChange func ()
onSelectionRequest func () (granted bool)
onSelectionMotionRequest func (tomo.SelectionDirection) (granted bool)
onScrollBoundsChange func ()
}
// NewTextBox creates a new text box with the specified placeholder text, and
// a value. When the value is empty, the placeholder will be displayed in gray
// text.
func NewTextBox (placeholder, value 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([]rune(placeholder))
element.updateMinimumSize()
element.SetValue(value)
return
}
func (element *TextBox) Resize (width, height int) {
element.core.AllocateCanvas(width, height)
element.scrollToCursor()
element.draw()
if element.onScrollBoundsChange != nil {
element.onScrollBoundsChange()
}
}
func (element *TextBox) HandleMouseDown (x, y int, button tomo.Button) {
if !element.enabled { return }
if !element.selected { element.Select() }
}
func (element *TextBox) HandleMouseUp (x, y int, button tomo.Button) { }
func (element *TextBox) HandleMouseMove (x, y int) { }
func (element *TextBox) HandleMouseScroll (x, y int, deltaX, deltaY float64) { }
func (element *TextBox) HandleKeyDown(key tomo.Key, modifiers tomo.Modifiers) {
if element.onKeyDown != nil && element.onKeyDown(key, modifiers) {
return
}
scrollMemory := element.scroll
altered := true
textChanged := false
switch {
case key == tomo.KeyBackspace:
if len(element.text) < 1 { break }
element.text, element.cursor = textmanip.Backspace (
element.text,
element.cursor,
modifiers.Control)
textChanged = true
case key == tomo.KeyDelete:
if len(element.text) < 1 { break }
element.text, element.cursor = textmanip.Delete (
element.text,
element.cursor,
modifiers.Control)
textChanged = true
case key == tomo.KeyLeft:
element.cursor = textmanip.MoveLeft (
element.text,
element.cursor,
modifiers.Control)
case key == tomo.KeyRight:
element.cursor = textmanip.MoveRight (
element.text,
element.cursor,
modifiers.Control)
case key.Printable():
element.text, element.cursor = textmanip.Type (
element.text,
element.cursor,
rune(key))
textChanged = true
default:
altered = false
}
if textChanged {
element.runOnChange()
element.valueDrawer.SetText(element.text)
}
if altered {
element.scrollToCursor()
}
if (textChanged || scrollMemory != element.scroll) &&
element.onScrollBoundsChange != nil {
element.onScrollBoundsChange()
}
if altered && element.core.HasImage () {
element.draw()
element.core.DamageAll()
}
}
func (element *TextBox) HandleKeyUp(key tomo.Key, modifiers tomo.Modifiers) { }
func (element *TextBox) Selected () (selected bool) {
return element.selected
}
func (element *TextBox) Select () {
if element.onSelectionRequest != nil {
element.onSelectionRequest()
}
}
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.DamageAll()
}
return true
}
func (element *TextBox) HandleDeselection () {
element.selected = false
if element.core.HasImage() {
element.draw()
element.core.DamageAll()
}
}
func (element *TextBox) OnSelectionRequest (callback func () (granted bool)) {
element.onSelectionRequest = callback
}
func (element *TextBox) OnSelectionMotionRequest (
callback func (direction tomo.SelectionDirection) (granted bool),
) {
element.onSelectionMotionRequest = callback
}
func (element *TextBox) SetEnabled (enabled bool) {
if element.enabled == enabled { return }
element.enabled = enabled
if element.core.HasImage () {
element.draw()
element.core.DamageAll()
}
}
func (element *TextBox) SetPlaceholder (placeholder string) {
if element.placeholder == placeholder { return }
element.placeholder = placeholder
element.placeholderDrawer.SetText([]rune(placeholder))
element.updateMinimumSize()
if element.core.HasImage () {
element.draw()
element.core.DamageAll()
}
}
func (element *TextBox) SetValue (text string) {
// if element.text == text { return }
element.text = []rune(text)
element.runOnChange()
element.valueDrawer.SetText(element.text)
if element.cursor > element.valueDrawer.Length() {
element.cursor = element.valueDrawer.Length()
}
element.scrollToCursor()
if element.core.HasImage () {
element.draw()
element.core.DamageAll()
}
}
func (element *TextBox) Value () (value string) {
return string(element.text)
}
func (element *TextBox) Filled () (filled bool) {
return len(element.text) > 0
}
func (element *TextBox) OnKeyDown (
callback func (key tomo.Key, modifiers tomo.Modifiers) (handled bool),
) {
element.onKeyDown = callback
}
func (element *TextBox) OnChange (callback func ()) {
element.onChange = callback
}
// ScrollContentBounds returns the full content size of the element.
func (element *TextBox) ScrollContentBounds () (bounds image.Rectangle) {
bounds = element.valueDrawer.LayoutBounds()
return bounds.Sub(bounds.Min)
}
// ScrollViewportBounds returns the size and position of the element's viewport
// relative to ScrollBounds.
func (element *TextBox) ScrollViewportBounds () (bounds image.Rectangle) {
return image.Rect (
element.scroll,
0,
element.scroll + element.scrollViewportWidth(),
0)
}
func (element *TextBox) scrollViewportWidth () (width int) {
return element.Bounds().Inset(theme.Padding()).Dx()
}
// ScrollTo scrolls the viewport to the specified point relative to
// ScrollBounds.
func (element *TextBox) ScrollTo (position image.Point) {
// constrain to minimum
element.scroll = position.X
if element.scroll < 0 { element.scroll = 0 }
// constrain to maximum
contentBounds := element.ScrollContentBounds()
maxPosition := contentBounds.Max.X - element.scrollViewportWidth()
if element.scroll > maxPosition { element.scroll = maxPosition }
if element.core.HasImage () {
element.draw()
element.core.DamageAll()
}
if element.onScrollBoundsChange != nil {
element.onScrollBoundsChange()
}
}
// ScrollAxes returns the supported axes for scrolling.
func (element *TextBox) ScrollAxes () (horizontal, vertical bool) {
return true, false
}
func (element *TextBox) OnScrollBoundsChange (callback func ()) {
element.onScrollBoundsChange = callback
}
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) runOnChange () {
if element.onChange != nil {
element.onChange()
}
}
func (element *TextBox) scrollToCursor () {
if !element.core.HasImage() { return }
bounds := element.core.Bounds().Inset(theme.Padding())
bounds.Max.X -= element.valueDrawer.Em().Round()
cursorPosition := element.valueDrawer.PositionOf(element.cursor)
cursorPosition.X -= element.scroll
maxX := bounds.Max.X
minX := maxX
if cursorPosition.X > maxX {
element.scroll += cursorPosition.X - maxX
} else if cursorPosition.X < minX {
element.scroll -= minX - cursorPosition.X
if element.scroll < 0 { element.scroll = 0 }
}
}
func (element *TextBox) draw () {
bounds := element.core.Bounds()
artist.FillRectangle (
element.core,
theme.InputPattern (
element.enabled,
element.Selected()),
bounds)
if len(element.text) == 0 && !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() - element.scroll,
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))
}
}
}