ui/input/system: introduce package for system events

And add ProfileOp and ProfileEvent for registering and receiving
profile data.

Remove the Profiling field and Timings method from app.Window.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

ui/app/internal/input/router.go

@@ -7,6 +7,7 @@ import (
 
 	"gioui.org/ui"
 	"gioui.org/ui/input"
+	"gioui.org/ui/input/system"
 	"gioui.org/ui/internal/ops"
 	"gioui.org/ui/key"
 	"gioui.org/ui/pointer"
@@ -21,9 +22,13 @@ type Router struct {
 	handlers handlerEvents
 
 	reader ui.OpsReader
+
 	// InvalidateOp summary.
 	redraw     bool
 	redrawTime time.Time
+
+	// ProfileOp summary.
+	profHandlers []input.Key
 }
 
 type handlerEvents struct {
@@ -38,6 +43,7 @@ func (q *Router) Events(k input.Key) []input.Event {
 func (q *Router) Frame(ops *ui.Ops) {
 	q.handlers.Clear()
 	q.redraw = false
+	q.profHandlers = q.profHandlers[:0]
 	q.reader.Reset(ops)
 	q.collect()
 
@@ -69,10 +75,24 @@ func (q *Router) collect() {
 				q.redraw = true
 				q.redrawTime = op.At
 			}
+		case ops.TypeProfile:
+			var op system.ProfileOp
+			op.Decode(encOp.Data, encOp.Refs)
+			q.profHandlers = append(q.profHandlers, op.Key)
 		}
 	}
 }
 
+func (q *Router) AddProfile(e system.ProfileEvent) {
+	for _, h := range q.profHandlers {
+		q.handlers.Add(h, e)
+	}
+}
+
+func (q *Router) Profiling() bool {
+	return len(q.profHandlers) > 0
+}
+
 func (q *Router) RedrawTime() (time.Time, bool) {
 	return q.redrawTime, q.redraw
 }

ui/app/window.go

@@ -13,6 +13,7 @@ import (
 	"gioui.org/ui/app/internal/gpu"
 	iinput "gioui.org/ui/app/internal/input"
 	"gioui.org/ui/input"
+	"gioui.org/ui/input/system"
 	"gioui.org/ui/key"
 )
 
@@ -23,13 +24,10 @@ type WindowOptions struct {
 }
 
 type Window struct {
-	Profiling bool
-
 	driver     *window
 	lastFrame  time.Time
 	drawStart  time.Time
 	gpu        *gpu.GPU
-	timings    string
 	inputState key.TextInputState
 	err        error
 
@@ -74,10 +72,6 @@ func (w *Window) Events() <-chan Event {
 	return w.events
 }
 
-func (w *Window) Timings() string {
-	return w.timings
-}
-
 func (w *Window) setTextInput(s key.TextInputState) {
 	if s != w.inputState && (s == key.TextInputClose || s == key.TextInputOpen) {
 		w.driver.setTextInput(s)
@@ -134,7 +128,7 @@ func (w *Window) Draw(root *ui.Ops) {
 			return
 		}
 	}
-	w.gpu.Draw(w.Profiling, size, root)
+	w.gpu.Draw(w.router.Profiling(), size, root)
 	w.router.Frame(root)
 	now := time.Now()
 	w.mu.Lock()
@@ -142,9 +136,10 @@ func (w *Window) Draw(root *ui.Ops) {
 	frameDur := now.Sub(w.lastFrame)
 	frameDur = frameDur.Truncate(100 * time.Microsecond)
 	w.lastFrame = now
-	if w.Profiling {
+	if w.router.Profiling() {
 		q := 100 * time.Microsecond
-		w.timings = fmt.Sprintf("tot:%7s cpu:%7s %s", frameDur.Round(q), drawDur.Round(q), w.gpu.Timings())
+		timings := fmt.Sprintf("tot:%7s cpu:%7s %s", frameDur.Round(q), drawDur.Round(q), w.gpu.Timings())
+		w.router.AddProfile(system.ProfileEvent{Timings: timings})
 		w.setNextFrame(time.Time{})
 	}
 	if t, ok := w.router.RedrawTime(); ok {

ui/input/system/system.go

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+// Package system contain ops and types for
+// system events.
+package system
+
+import (
+	"gioui.org/ui"
+	"gioui.org/ui/input"
+	"gioui.org/ui/internal/ops"
+)
+
+// ProfileOp registers a handler for receiving
+// ProfileEvents.
+type ProfileOp struct {
+	Key input.Key
+}
+
+// ProfileEvent contain profile data from a single
+// rendered frame.
+type ProfileEvent struct {
+	// String with timings. Very likely to change.
+	Timings string
+}
+
+func (p ProfileOp) Add(o *ui.Ops) {
+	data := make([]byte, ops.TypeProfileLen)
+	data[0] = byte(ops.TypeProfile)
+	o.Write(data, p.Key)
+}
+
+func (p *ProfileOp) Decode(d []byte, refs []interface{}) {
+	if ops.OpType(d[0]) != ops.TypeProfile {
+		panic("invalid op")
+	}
+	*p = ProfileOp{
+		Key: refs[0].(input.Key),
+	}
+}
+
+func (p ProfileEvent) ImplementsInputEvent() {}

ui/internal/ops/ops.go

@@ -23,6 +23,7 @@ const (
 	TypePop
 	TypeAux
 	TypeClip
+	TypeProfile
 )
 
 const (
@@ -43,6 +44,7 @@ const (
 	TypePopLen            = 1
 	TypeAuxLen            = 1 + 4
 	TypeClipLen           = 1 + 4*4
+	TypeProfileLen        = 1
 )
 
 func (t OpType) Size() int {
@@ -64,12 +66,13 @@ func (t OpType) Size() int {
 		TypePopLen,
 		TypeAuxLen,
 		TypeClipLen,
+		TypeProfileLen,
 	}[t-firstOpIndex]
 }
 
 func (t OpType) NumRefs() int {
 	switch t {
-	case TypeBlock, TypeImage, TypeKeyHandler, TypePointerHandler:
+	case TypeBlock, TypeImage, TypeKeyHandler, TypePointerHandler, TypeProfile:
 		return 1
 	default:
 		return 0