// OnEvent process a particularevent on the button.
func (b *Button) OnEvent(e interface{}) {
switch e.(type) {
case sparta.CloseEvent:
if b.closeFn != nil {
b.closeFn(b, e)
}
case sparta.ConfigureEvent:
b.geometry = e.(sparta.ConfigureEvent).Rect
if b.configFn != nil {
b.configFn(b, e)
}
case sparta.CommandEvent:
if b.commFn != nil {
if b.commFn(b, e) {
return
}
}
b.parent.OnEvent(e)
case sparta.ExposeEvent:
if b.exposeFn != nil {
b.exposeFn(b, e)
}
b.win.SetColor(sparta.Foreground, foreColor)
if len(b.caption) > 0 {
x := (b.geometry.Dx() - (len(b.caption) * sparta.WidthUnit)) / 2
y := (b.geometry.Dy() - sparta.HeightUnit) / 2
b.win.Text(image.Pt(x, y), b.caption)
}
rect := image.Rect(0, 0, b.geometry.Dx()-1, b.geometry.Dy()-1)
b.win.Rectangle(rect, false)
case sparta.KeyEvent:
if sparta.IsBlock() {
if !sparta.IsBlocker(b) {
return
}
}
if b.keyFn != nil {
if b.keyFn(b, e) {
return
}
}
case sparta.MouseEvent:
if sparta.IsBlock() {
if !sparta.IsBlocker(b) {
return
}
}
if b.mouseFn != nil {
if b.mouseFn(b, e) {
return
}
}
ev := e.(sparta.MouseEvent)
if ev.Button == sparta.MouseLeft {
sparta.SendEvent(b.target, sparta.CommandEvent{Source: b, Value: b.value})
}
}
}
func main() {
rand.Seed(time.Now().Unix())
// The main window.
m := widget.NewMainWindow("main", "Event Window")
// Functions to capture the events.
//
// Capture close event.This event is produced when attepting to
// close a rootless widget (such as MainWindow), or when a child
// is closed.
m.Capture(sparta.CloseEv, closeFunc)
// Capture command event. This event is produced when another
// process, or a widget send a message to another widget.
m.Capture(sparta.Command, commandFunc)
// Capture configure event. This event is produced when a widget
// changes its size.
m.Capture(sparta.Configure, configureFunc)
// Capture Expose event. This event is produced when a previously
// obscured part of a widget is exposed (in some backends, other
// backends save obscured part of the widget and simply copy them
// when the widget is exposed. Expose event are also produced when
// the widget is resized (configure), and when an explicit update
// method is called.
m.Capture(sparta.Expose, exposeFunc)
// Capture Key event. This event is produced when a key in the
// keyboard is pressed or released.
m.Capture(sparta.KeyEv, keyFunc)
// Capture Mouse event. This event is produced when the mouse is
// moved, a button is pressed or released.
m.Capture(sparta.Mouse, mouseFunc)
// this helper function is used to send command events to the window.
// it will send a random number each second.
go func() {
for {
time.Sleep(10 * time.Second)
sparta.SendEvent(m, sparta.CommandEvent{Value: rand.Intn(255)})
}
}()
sparta.Run()
}
// OnEvent process a particular event on the list.
func (l *List) OnEvent(e interface{}) {
switch e.(type) {
case sparta.CloseEvent:
if l.closeFn != nil {
l.closeFn(l, e)
}
l.scroll.OnEvent(e)
case sparta.ConfigureEvent:
rect := e.(sparta.ConfigureEvent).Rect
l.geometry = rect
if l.configFn != nil {
l.configFn(l, e)
}
l.scroll.SetProperty(sparta.Geometry, image.Rect(rect.Dx()-10, 0, rect.Dx(), rect.Dy()))
l.scroll.SetProperty(ScrollPage, l.geometry.Dy()/sparta.HeightUnit)
case sparta.CommandEvent:
if l.commFn != nil {
if l.commFn(l, e) {
return
}
}
ev := e.(sparta.CommandEvent)
if ev.Source == l.scroll {
l.Update()
return
}
l.parent.OnEvent(e)
case sparta.ExposeEvent:
if l.exposeFn != nil {
l.exposeFn(l, e)
}
l.win.SetColor(sparta.Foreground, foreColor)
if (l.list != nil) && (l.list.Len() > 0) {
pos := l.scroll.Property(ScrollPos).(int)
if pos < 0 {
pos = 0
}
page := l.scroll.Property(ScrollPage).(int)
for i := 0; i <= page; i++ {
j := i + pos
if j >= l.list.Len() {
break
}
if l.list.IsSel(j) {
y := (i * sparta.HeightUnit) + 2
l.win.Text(image.Pt(2, y), ">")
}
l.win.Text(image.Pt(2+sparta.WidthUnit, (i*sparta.HeightUnit)+2), l.list.Item(j))
}
}
rect := image.Rect(0, 0, l.geometry.Dx()-1, l.geometry.Dy()-1)
l.win.Rectangle(rect, false)
case sparta.KeyEvent:
if s.keyFn != nil {
if s.keyFn(s, e) {
return
}
}
pos := l.scroll.Property(ScrollPos).(int)
page := l.scroll.Property(ScrollPage).(int)
ev := e.(sparta.KeyEvent)
switch ev.Key {
case sparta.KeyDown:
l.scroll.SetProperty(ScrollPos, pos+1)
case sparta.KeyUp:
l.scroll.SetProperty(ScrollPos, pos-1)
case sparta.KeyPageUp:
l.scroll.SetProperty(ScrollPos, pos-page)
case sparta.KeyPageDown:
l.scroll.SetProperty(ScrollPos, pos+page)
case sparta.KeyHome:
l.scroll.SetProperty(ScrollPos, 0)
case sparta.KeyEnd:
s.SetProperty(ScrollPos, l.list.Len())
default:
l.parent.OnEvent(e)
}
case sparta.MouseEvent:
if l.mouseFn != nil {
if l.mouseFn(l, e) {
return
}
}
pos := l.scroll.Property(ScrollPos).(int)
ev := e.(sparta.MouseEvent)
switch ev.Button {
case -sparta.MouseWheel:
l.scroll.SetProperty(ScrollPos, pos+1)
case sparta.MouseWheel:
l.scroll.SetProperty(ScrollPos, pos-1)
case sparta.MouseLeft:
p := ((ev.Loc.Y - 2) / sparta.HeightUnit) + pos
sparta.SendEvent(l.target, sparta.CommandEvent{Source: l, Value: p})
case sparta.MouseRight:
p := ((ev.Loc.Y - 2) / sparta.HeightUnit) + pos
sparta.SendEvent(l.target, sparta.CommandEvent{Source: l, Value: -(p + 1)})
}
}
}
// SetProperty sets a property of the scroll.
func (s *Scroll) SetProperty(p sparta.Property, v interface{}) {
switch p {
case sparta.Data:
s.data = v
case sparta.Geometry:
val := v.(image.Rectangle)
if !s.geometry.Eq(val) {
s.win.SetProperty(sparta.Geometry, val)
}
case sparta.Parent:
if v == nil {
s.parent = nil
}
case sparta.Name:
val := v.(string)
if s.name != val {
s.name = val
}
case sparta.Foreground:
val := v.(color.RGBA)
if s.fore != val {
s.fore = val
s.win.SetProperty(sparta.Foreground, val)
}
case sparta.Background:
val := v.(color.RGBA)
if s.back != val {
s.back = val
s.win.SetProperty(sparta.Background, val)
}
case sparta.Target:
val := v.(sparta.Widget)
if val == nil {
val = s.parent
}
if s.target == val {
break
}
s.target = val
case ScrollPage:
val := v.(int)
if val < 0 {
break
}
if s.page == val {
break
}
s.page = val
if ((s.size - s.page) > 0) && (s.pos > (s.size - s.page)) {
s.pos = s.size - s.page
sparta.SendEvent(s.target, sparta.CommandEvent{Source: s, Value: s.pos})
}
s.Update()
case ScrollPos:
val := v.(int)
if val < 0 {
val = 0
} else if val > (s.size - s.page) {
val = s.size - s.page
}
if s.pos == val {
break
}
s.pos = val
sparta.SendEvent(s.target, sparta.CommandEvent{Source: s, Value: s.pos})
s.Update()
case ScrollSize:
val := v.(int)
if val < 0 {
break
}
if s.size == val {
break
}
s.size = val
if s.size == 0 {
s.page = 0
s.pos = 0
} else if (s.page < s.size) && (s.pos > (s.size - s.page)) {
s.pos = s.size - s.page
sparta.SendEvent(s.target, sparta.CommandEvent{Source: s, Value: s.pos})
}
s.Update()
}
}