From bfece0bebacb5cec4fdf5682b886333e03b6549b Mon Sep 17 00:00:00 2001
From: Elias Naur <mail@eliasnaur.com>
Date: Thu, 1 Aug 2019 10:06:19 +0200
Subject: [PATCH] ui: change area ops to use rectangles, not sizes

And then use the more general rectangles to add a buffer around
text.Editor click and scroll area.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
---
 ui/app/internal/input/pointer.go | 30 +++++++++++++++++++++---------
 ui/internal/ops/ops.go           |  2 +-
 ui/layout/list.go                |  2 +-
 ui/pointer/pointer.go            | 16 +++++++++-------
 ui/text/editor.go                |  8 +++++++-
 5 files changed, 39 insertions(+), 19 deletions(-)

diff --git a/ui/app/internal/input/pointer.go b/ui/app/internal/input/pointer.go
index 4f7b79eb..a6d6cd47 100644
--- a/ui/app/internal/input/pointer.go
+++ b/ui/app/internal/input/pointer.go
@@ -47,7 +47,7 @@ type pointerHandler struct {
 
 type areaOp struct {
 	kind areaKind
-	size image.Point
+	rect image.Rectangle
 }
 
 type areaNode struct {
@@ -268,28 +268,40 @@ func (op *areaOp) Decode(d []byte) {
 		panic("invalid op")
 	}
 	bo := binary.LittleEndian
-	size := image.Point{
-		X: int(bo.Uint32(d[2:])),
-		Y: int(bo.Uint32(d[6:])),
+	rect := image.Rectangle{
+		Min: image.Point{
+			X: int(int32(bo.Uint32(d[2:]))),
+			Y: int(int32(bo.Uint32(d[6:]))),
+		},
+		Max: image.Point{
+			X: int(int32(bo.Uint32(d[10:]))),
+			Y: int(int32(bo.Uint32(d[14:]))),
+		},
 	}
 	*op = areaOp{
 		kind: areaKind(d[1]),
-		size: size,
+		rect: rect,
 	}
 }
 
 func (op *areaOp) Hit(pos f32.Point) bool {
+	min := f32.Point{
+		X: float32(op.rect.Min.X),
+		Y: float32(op.rect.Min.Y),
+	}
+	pos = pos.Sub(min)
+	size := op.rect.Size()
 	switch op.kind {
 	case areaRect:
-		if 0 <= pos.X && pos.X < float32(op.size.X) &&
-			0 <= pos.Y && pos.Y < float32(op.size.Y) {
+		if 0 <= pos.X && pos.X < float32(size.X) &&
+			0 <= pos.Y && pos.Y < float32(size.Y) {
 			return true
 		} else {
 			return false
 		}
 	case areaEllipse:
-		rx := float32(op.size.X) / 2
-		ry := float32(op.size.Y) / 2
+		rx := float32(size.X) / 2
+		ry := float32(size.Y) / 2
 		rx2 := rx * rx
 		ry2 := ry * ry
 		xh := pos.X - rx
diff --git a/ui/internal/ops/ops.go b/ui/internal/ops/ops.go
index abc8f581..0cb6fe02 100644
--- a/ui/internal/ops/ops.go
+++ b/ui/internal/ops/ops.go
@@ -35,7 +35,7 @@ const (
 	TypeImageLen          = 1 + 4*4
 	TypeDrawLen           = 1 + 4*4
 	TypeColorLen          = 1 + 4
-	TypeAreaLen           = 1 + 1 + 2*4
+	TypeAreaLen           = 1 + 1 + 4*4
 	TypePointerHandlerLen = 1 + 1
 	TypePassLen           = 1 + 1
 	TypeKeyHandlerLen     = 1 + 1
diff --git a/ui/layout/list.go b/ui/layout/list.go
index 2df153db..96c79558 100644
--- a/ui/layout/list.go
+++ b/ui/layout/list.go
@@ -243,7 +243,7 @@ func (l *List) Layout() Dimens {
 	}
 	dims := axisPoint(l.Axis, mainc.Constrain(pos), maxCross)
 	l.macro.Stop()
-	pointer.RectAreaOp{Size: dims}.Add(ops)
+	pointer.RectAreaOp{Rect: image.Rectangle{Max: dims}}.Add(ops)
 	l.scroll.Add(ops)
 	l.macro.Add(ops)
 	return Dimens{Size: dims}
diff --git a/ui/pointer/pointer.go b/ui/pointer/pointer.go
index f19331aa..92b43ab6 100644
--- a/ui/pointer/pointer.go
+++ b/ui/pointer/pointer.go
@@ -25,17 +25,17 @@ type Event struct {
 }
 
 type RectAreaOp struct {
-	Size image.Point
+	Rect image.Rectangle
 }
 
 type EllipseAreaOp struct {
-	Size image.Point
+	Rect image.Rectangle
 }
 
 // Must match the structure in input.areaOp
 type areaOp struct {
 	kind areaKind
-	size image.Point
+	rect image.Rectangle
 }
 
 type HandlerOp struct {
@@ -83,14 +83,14 @@ const (
 func (op RectAreaOp) Add(ops *ui.Ops) {
 	areaOp{
 		kind: areaRect,
-		size: op.Size,
+		rect: op.Rect,
 	}.add(ops)
 }
 
 func (op EllipseAreaOp) Add(ops *ui.Ops) {
 	areaOp{
 		kind: areaEllipse,
-		size: op.Size,
+		rect: op.Rect,
 	}.add(ops)
 }
 
@@ -99,8 +99,10 @@ func (op areaOp) add(o *ui.Ops) {
 	data[0] = byte(ops.TypeArea)
 	data[1] = byte(op.kind)
 	bo := binary.LittleEndian
-	bo.PutUint32(data[2:], uint32(op.size.X))
-	bo.PutUint32(data[6:], uint32(op.size.Y))
+	bo.PutUint32(data[2:], uint32(op.rect.Min.X))
+	bo.PutUint32(data[6:], uint32(op.rect.Min.Y))
+	bo.PutUint32(data[10:], uint32(op.rect.Max.X))
+	bo.PutUint32(data[14:], uint32(op.rect.Max.Y))
 	o.Write(data)
 }
 
diff --git a/ui/text/editor.go b/ui/text/editor.go
index 3659ee5b..327abfb7 100644
--- a/ui/text/editor.go
+++ b/ui/text/editor.go
@@ -248,7 +248,13 @@ func (e *Editor) Layout(cfg ui.Config, queue input.Queue, ops *ui.Ops, cs layout
 	stack.Pop()
 
 	baseline := e.padTop + e.dims.Baseline
-	pointer.RectAreaOp{Size: e.viewSize}.Add(ops)
+	pointerPadding := cfg.Px(ui.Dp(4))
+	r := image.Rectangle{Max: e.viewSize}
+	r.Min.X -= pointerPadding
+	r.Min.Y -= pointerPadding
+	r.Max.X += pointerPadding
+	r.Max.X += pointerPadding
+	pointer.RectAreaOp{Rect: r}.Add(ops)
 	e.scroller.Add(ops)
 	e.clicker.Add(ops)
 	return layout.Dimens{Size: e.viewSize, Baseline: baseline}