Add feedback components 106-130; inert scope, focus return, two-step deploy

feedback/loadingscreen.go

@@ -0,0 +1,38 @@
+package feedback
+
+import (
+	"strings"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type LoadingScreenOptions struct {
+	// Tips take turns, four seconds each.
+	Tips []string
+	// Width is in dots; zero means 240.
+	Width int
+}
+
+// LoadingScreen shows NOW LOADING, stepping dots and a tip.
+func LoadingScreen(c *ui.Context, o LoadingScreenOptions) *ui.Element {
+	k := pixel.K(c)
+	w := pixel.Or("LoadingScreen Width", o.Width, 240)
+	title := k.Msg("loading")
+	return ui.Box(c).Role(ui.RoleStatus).Label(title).Size(k.D(w), k.D(2*pixel.LineHeight+8+2*pixel.LineHeight)).Draw(func(p *ui.Painter, r ui.Rect) {
+		g := k.Canvas(p, r)
+		n := g.Busy(4)
+		line := title + strings.Repeat(".", n%4)
+		x := (w - pixel.Measure(title+"...")*2) / 2
+		g.Text(x+2, 2, line, pixel.Shade, 2)
+		g.Text(x, 0, line, pixel.Accent, 2)
+		if len(o.Tips) == 0 {
+			return
+		}
+		tip := o.Tips[n/16%len(o.Tips)]
+		for i, l := range pixel.Wrap(tip, w, 2) {
+			g.Text((w-pixel.Measure(l))/2, 2*pixel.LineHeight+8+i*pixel.LineHeight, l, pixel.Faint, 1)
+		}
+	})
+}