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tomo-old/elements/basic/button.go

210 lines
5.1 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/elements/core"
// Button is a clickable button.
type Button struct {
*core.Core
core core.CoreControl
pressed bool
enabled bool
selected bool
text string
drawer artist.TextDrawer
onClick func ()
onSelectionRequest func () (granted bool)
onSelectionMotionRequest func (tomo.SelectionDirection) (granted bool)
}
// NewButton creates a new button with the specified label text.
func NewButton (text string) (element *Button) {
element = &Button { enabled: true }
element.Core, element.core = core.NewCore(element)
element.drawer.SetFace(theme.FontFaceRegular())
element.SetText(text)
return
}
func (element *Button) Resize (width, height int) {
element.core.AllocateCanvas(width, height)
element.draw()
}
func (element *Button) HandleMouseDown (x, y int, button tomo.Button) {
if !element.enabled { return }
if !element.selected { element.Select() }
if button != tomo.ButtonLeft { return }
element.pressed = true
if element.core.HasImage() {
element.draw()
element.core.DamageAll()
}
}
func (element *Button) HandleMouseUp (x, y int, button tomo.Button) {
if button != tomo.ButtonLeft { return }
element.pressed = false
if element.core.HasImage() {
element.draw()
element.core.DamageAll()
}
within := image.Point { x, y }.
In(element.Bounds())
if !element.enabled { return }
if within && element.onClick != nil {
element.onClick()
}
}
func (element *Button) HandleMouseMove (x, y int) { }
func (element *Button) HandleMouseScroll (x, y int, deltaX, deltaY float64) { }
func (element *Button) HandleKeyDown (key tomo.Key, modifiers tomo.Modifiers) {
if !element.enabled { return }
if key == tomo.KeyEnter {
element.pressed = true
if element.core.HasImage() {
element.draw()
element.core.DamageAll()
}
}
}
func (element *Button) HandleKeyUp(key tomo.Key, modifiers tomo.Modifiers) {
if key == tomo.KeyEnter && element.pressed {
element.pressed = false
if element.core.HasImage() {
element.draw()
element.core.DamageAll()
}
if !element.enabled { return }
if element.onClick != nil {
element.onClick()
}
}
}
func (element *Button) Selected () (selected bool) {
return element.selected
}
func (element *Button) Select () {
if !element.enabled { return }
if element.onSelectionRequest != nil {
element.onSelectionRequest()
}
}
func (element *Button) 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 *Button) HandleDeselection () {
element.selected = false
if element.core.HasImage() {
element.draw()
element.core.DamageAll()
}
}
func (element *Button) OnSelectionRequest (callback func () (granted bool)) {
element.onSelectionRequest = callback
}
func (element *Button) OnSelectionMotionRequest (
callback func (direction tomo.SelectionDirection) (granted bool),
) {
element.onSelectionMotionRequest = callback
}
// OnClick sets the function to be called when the button is clicked.
func (element *Button) OnClick (callback func ()) {
element.onClick = callback
}
// SetEnabled sets whether this button can be clicked or not.
func (element *Button) SetEnabled (enabled bool) {
if element.enabled == enabled { return }
element.enabled = enabled
if element.core.HasImage () {
element.draw()
element.core.DamageAll()
}
}
// SetText sets the button's label text.
func (element *Button) SetText (text string) {
if element.text == text { return }
element.text = text
element.drawer.SetText([]rune(text))
textBounds := element.drawer.LayoutBounds()
element.core.SetMinimumSize (
theme.Padding() * 2 + textBounds.Dx(),
theme.Padding() * 2 + textBounds.Dy())
if element.core.HasImage () {
element.draw()
element.core.DamageAll()
}
}
func (element *Button) draw () {
bounds := element.core.Bounds()
artist.FillRectangle (
element.core,
theme.ButtonPattern (
element.enabled,
element.Selected(),
element.pressed),
bounds)
innerBounds := bounds
innerBounds.Min.X += theme.Padding()
innerBounds.Min.Y += theme.Padding()
innerBounds.Max.X -= theme.Padding()
innerBounds.Max.Y -= theme.Padding()
textBounds := element.drawer.LayoutBounds()
offset := image.Point {
X: theme.Padding() + (innerBounds.Dx() - textBounds.Dx()) / 2,
Y: theme.Padding() + (innerBounds.Dy() - textBounds.Dy()) / 2,
}
// account for the fact that the bounding rectangle will be shifted over
// due to the bounds origin being at the baseline of the first line
offset.Y -= textBounds.Min.Y
offset.X -= textBounds.Min.X
if element.pressed {
offset = offset.Add(theme.SinkOffsetVector())
}
foreground := theme.ForegroundPattern(element.enabled)
element.drawer.Draw(element.core, foreground, offset)
}