1 files changed, 106 insertions, 0 deletions
diff --git a/gui/cmd/spike/main.go b/gui/cmd/spike/main.go
new file mode 100644
index 0000000..442df52
--- /dev/null
+++ b/gui/cmd/spike/main.go
@@ -0,0 +1,106 @@
+// Spike: prove that a Plan 9 GUI can be written in Go with nothing but the
+// standard library -- no C, no cgo, no libdraw, no window system.
+//
+// Draws a panel layout and a cursor block that tracks the mouse.
+// Button 3 quits; so does the deadline, so a forgotten instance on a VM
+// does not sit on /dev/draw forever.
+package main
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"9front/gui/draw"
+)
+
+func main() {
+	if err := run(); err != nil {
+		fmt.Fprintf(os.Stderr, "spike: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func run() error {
+	d, err := draw.Init("/dev")
+	if err != nil {
+		return err
+	}
+	defer d.Close()
+	if d.Screen == nil {
+		return fmt.Errorf("draw device gave no screen image")
+	}
+	scr := d.Screen
+	r := scr.Rect()
+	fmt.Fprintf(os.Stderr, "spike: screen %dx%d\n", r.Dx(), r.Dy())
+
+	col := map[string]uint32{}
+	img := map[string]*draw.Image{}
+	for name, v := range map[string]uint32{
+		"bg":     0x2B3A42FF,
+		"panel":  0x3F5765FF,
+		"accent": 0xBDD4DEFF,
+		"hot":    0xEFA00BFF,
+	} {
+		col[name] = v
+		if img[name], err = d.Color(v); err != nil {
+			return err
+		}
+	}
+
+	// Static layout: a header bar and three panels, laid out by arithmetic
+	// rather than by hand-placed constants.  This is the seam where a real
+	// layout pass would go.
+	repaint := func() {
+		draw.Draw(scr, r, img["bg"], nil, draw.ZP)
+		hdr := draw.Rect(r.Min.X, r.Min.Y, r.Max.X, r.Min.Y+40)
+		draw.Draw(scr, hdr, img["accent"], nil, draw.ZP)
+
+		const gap = 12
+		top := r.Min.Y + 40 + gap
+		w := (r.Dx() - 4*gap) / 3
+		for i := int32(0); i < 3; i++ {
+			x := r.Min.X + gap + i*(w+gap)
+			p := draw.Rect(x, top, x+w, r.Max.Y-gap)
+			draw.Draw(scr, p, img["panel"], nil, draw.ZP)
+		}
+	}
+	repaint()
+	d.Flush()
+
+	mc, err := draw.OpenMouse("/dev")
+	if err != nil {
+		return err
+	}
+	defer mc.Close()
+
+	deadline := time.After(10 * time.Minute)
+	cursor := draw.Rect(0, 0, 28, 28)
+	var last draw.Rectangle
+	for {
+		select {
+		case m, ok := <-mc.C:
+			if !ok {
+				return nil
+			}
+			if m.Buttons&4 != 0 {
+				return nil
+			}
+			// Damage repair without a full repaint: erase where the
+			// block was, then draw it where the mouse is now.
+			if last != (draw.Rectangle{}) {
+				repaint()
+			}
+			now := cursor.Add(draw.Point{X: m.X - 14, Y: m.Y - 14})
+			draw.Draw(scr, now, img["hot"], nil, draw.ZP)
+			d.Flush()
+			last = now
+		case <-mc.Resize:
+			r = scr.Rect()
+			repaint()
+			d.Flush()
+		case <-deadline:
+			return nil
+		}
+	}
+}