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tomo-old/elements/core/core.go

237 lines
6.7 KiB
Go

package core
import "image"
import "image/color"
import "golang.org/x/image/font"
import "git.tebibyte.media/sashakoshka/tomo/theme"
import "git.tebibyte.media/sashakoshka/tomo/config"
import "git.tebibyte.media/sashakoshka/tomo/canvas"
import "git.tebibyte.media/sashakoshka/tomo/artist"
// Core is a struct that implements some core functionality common to most
// widgets. It is meant to be embedded directly into a struct.
type Core struct {
canvas canvas.Canvas
metrics struct {
minimumWidth int
minimumHeight int
}
config config.Config
theme theme.Theme
c theme.Case
handleSizeChange func ()
handleConfigChange func ()
handleThemeChange func ()
onMinimumSizeChange func ()
onDamage func (region canvas.Canvas)
}
// NewCore creates a new element core and its corresponding control.
func NewCore (
handleSizeChange func (),
handleConfigChange func (),
handleThemeChange func (),
c theme.Case,
) (
core *Core,
control CoreControl,
) {
core = &Core {
handleSizeChange: handleSizeChange,
handleConfigChange: handleConfigChange,
handleThemeChange: handleThemeChange,
c: c,
}
control = CoreControl { core: core }
return
}
// ColorModel fulfills the draw.Image interface.
func (core *Core) ColorModel () (model color.Model) {
return color.RGBAModel
}
// ColorModel fulfills the draw.Image interface.
func (core *Core) At (x, y int) (pixel color.Color) {
if core.canvas == nil { return }
return core.canvas.At(x, y)
}
// ColorModel fulfills the draw.Image interface.
func (core *Core) Bounds () (bounds image.Rectangle) {
if core.canvas == nil { return }
return core.canvas.Bounds()
}
// ColorModel fulfills the draw.Image interface.
func (core *Core) Set (x, y int, c color.Color) () {
if core.canvas == nil { return }
core.canvas.Set(x, y, c)
}
// Buffer fulfills the canvas.Canvas interface.
func (core *Core) Buffer () (data []color.RGBA, stride int) {
if core.canvas == nil { return }
return core.canvas.Buffer()
}
// MinimumSize fulfils the tomo.Element interface. This should not need to be
// overridden.
func (core *Core) MinimumSize () (width, height int) {
return core.metrics.minimumWidth, core.metrics.minimumHeight
}
// DrawTo fulfills the tomo.Element interface. This should not need to be
// overridden.
func (core *Core) DrawTo (canvas canvas.Canvas) {
core.canvas = canvas
if core.handleSizeChange != nil {
core.handleSizeChange()
}
}
// OnDamage fulfils the tomo.Element interface. This should not need to be
// overridden.
func (core *Core) OnDamage (callback func (region canvas.Canvas)) {
core.onDamage = callback
}
// OnMinimumSizeChange fulfils the tomo.Element interface. This should not need
// to be overridden.
func (core *Core) OnMinimumSizeChange (callback func ()) {
core.onMinimumSizeChange = callback
}
// SetConfig fulfills the elements.Configurable interface. This should not need
// to be overridden.
func (core *Core) SetConfig (config config.Config) {
core.config = config
if core.handleConfigChange != nil {
core.handleConfigChange()
}
}
// SetTheme fulfills the elements.Themeable interface. This should not need
// to be overridden.
func (core *Core) SetTheme (theme theme.Theme) {
core.theme = theme
if core.handleThemeChange != nil {
core.handleThemeChange()
}
}
// CoreControl is a struct that can exert control over a Core struct. It can be
// used as a canvas. It must not be directly embedded into an element, but
// instead kept as a private member. When a Core struct is created, a
// corresponding CoreControl struct is linked to it and returned alongside it.
type CoreControl struct {
core *Core
}
// HasImage returns true if the core has an allocated image buffer, and false if
// it doesn't.
func (control CoreControl) HasImage () (has bool) {
return control.core.canvas != nil && !control.core.canvas.Bounds().Empty()
}
// DamageRegion pushes the selected region of pixels to the parent element. This
// does not need to be called when responding to a resize event.
func (control CoreControl) DamageRegion (bounds image.Rectangle) {
if control.core.onDamage != nil {
control.core.onDamage(canvas.Cut(control.core, bounds))
}
}
// DamageAll pushes all pixels to the parent element. This does not need to be
// called when redrawing in response to a change in size.
func (control CoreControl) DamageAll () {
control.DamageRegion(control.core.Bounds())
}
// SetMinimumSize sets the minimum size of this element, notifying the parent
// element in the process.
func (control CoreControl) SetMinimumSize (width, height int) {
core := control.core
if width == core.metrics.minimumWidth &&
height == core.metrics.minimumHeight {
return
}
core.metrics.minimumWidth = width
core.metrics.minimumHeight = height
if control.core.onMinimumSizeChange != nil {
control.core.onMinimumSizeChange()
}
}
// ConstrainSize contstrains the specified width and height to the minimum width
// and height, and returns wether or not anything ended up being constrained.
func (control CoreControl) ConstrainSize (
inWidth, inHeight int,
) (
outWidth, outHeight int,
constrained bool,
) {
core := control.core
outWidth = inWidth
outHeight = inHeight
if outWidth < core.metrics.minimumWidth {
outWidth = core.metrics.minimumWidth
constrained = true
}
if outHeight < core.metrics.minimumHeight {
outHeight = core.metrics.minimumHeight
constrained = true
}
return
}
// Config returns the current configuration.
func (control CoreControl) Config () (config.Config) {
return control.core.config
}
// Theme returns the current theme.
func (control CoreControl) Theme () (theme.Theme) {
return control.core.theme
}
// FontFace is like Theme.FontFace, but it automatically applies the correct
// case.
func (control CoreControl) FontFace (
style theme.FontStyle,
size theme.FontSize,
) (
face font.Face,
) {
return control.core.theme.FontFace(style, size, control.core.c)
}
// Icon is like Theme.Icon, but it automatically applies the correct case.
func (control CoreControl) Icon (name string) (artist.Pattern) {
return control.core.theme.Icon(name, control.core.c)
}
// Pattern is like Theme.Pattern, but it automatically applies the correct case.
func (control CoreControl) Pattern (
id theme.Pattern,
state theme.PatternState,
) (
pattern artist.Pattern,
) {
return control.core.theme.Pattern(id, control.core.c, state)
}
// Inset is like Theme.Inset, but it automatically applies the correct case.
func (control CoreControl) Inset (id theme.Pattern) (inset theme.Inset) {
return control.core.theme.Inset(id, control.core.c)
}
// Sink is like Theme.Sink, but it automatically applies the correct case.
func (control CoreControl) Sink (id theme.Pattern) (offset image.Point) {
return control.core.theme.Sink(id, control.core.c)
}