func NewControlPoint(value, colValue values.Value) canvas.Item {
cp := new(ControlPoint)
cp.value = value
cp.col = image.Black
cp.colValue = colValue
cp.backing = (*canvas.Canvas)(nil)
go cp.listener()
return canvas.Draggable(cp)
}
func (ctxt *context) setFractal(f Fractal, centre draw.Point) {
if ctxt.item != nil {
ctxt.tiler.Stop()
ctxt.cvs.Delete(ctxt.item)
}
ctxt.f = f
ctxt.tiler = NewTiler(f, ctxt.cache, *tileSize)
ctxt.item = canvas.Draggable(canvas.Moveable(ctxt.tiler))
ctxt.item.SetCentre(centre)
ctxt.cvs.AddItem(ctxt.item)
ctxt.cvs.Flush()
}
func main() {
win, err := x11.NewWindow()
if win == nil {
log.Fatalf("no window: %v", err)
}
screen := win.Screen()
bg := canvas.NewBackground(screen.(*image.RGBA), image.White, flushFunc(win))
cvs = canvas.NewCanvas(nil, bg.Rect())
bg.SetItem(cvs)
item := canvas.Draggable(canvas.Moveable(
canvas.NewText(
image.ZP,
0,
"Hello, world",
defaultFont(),
30,
nil)))
item.SetCentre(image.Pt(cvs.Rect().Dx()/2, cvs.Rect().Dy()/3))
cvs.AddItem(item)
// txtitem := canvas.NewText(
// image.Pt(100, 100),
// 0,
// "Working?",
// defaultFont(),
// 20,
// nil)
// img := canvas.ImageOf(txtitem)
// cvs.AddItem(canvas.NewImage(img, false, image.Pt(cvs.Width() / 2, cvs.Height()*2/3)))
cvs.Flush()
ec := win.EventChan()
for {
switch e := (<-ec).(type) {
case nil:
log.Fatal("quitting")
return
case draw.MouseEvent:
if e.Buttons == 0 {
break
}
cvs.HandleMouse(cvs, e, ec)
}
}
}
func monitor(mkball <-chan ball, delball <-chan bool, pause <-chan bool) {
ballcountText := canvas.NewText(
image.Pt(window.Rect().Max.X-5, 5), canvas.N|canvas.E, "0 balls", defaultFont(), 30, nil)
window.AddItem(canvas.Draggable(ballcountText))
ballcountText.SetFill(image.NewUniform(red))
window.Flush()
ctl := make(chan (chan<- bool))
nballs := 0
for {
select {
case b := <-mkball:
go animateBall(ctl, b)
nballs++
ballcountText.SetText(fmt.Sprintf("%d balls", nballs))
window.Flush()
case <-pause:
reply := make(chan bool)
for i := 0; i < nballs; i++ {
ctl <- reply
}
<-pause
for i := 0; i < nballs; i++ {
<-reply
}
case <-delball:
// delete a random ball
if nballs > 0 {
ctl <- nil
nballs--
ballcountText.SetText(fmt.Sprintf("%d balls", nballs))
window.Flush()
}
}
}
}
func makeRect(r image.Rectangle, col color.Color) {
img := canvas.Box(r.Dx(), r.Dy(), image.NewUniform(col), 1, image.Black)
item := canvas.NewImage(img, opaqueColor(col), r.Min)
window.AddItem(canvas.Draggable(item))
}