From 639810fb13a2e1050abef7592ab0a0b2a81fca4b Mon Sep 17 00:00:00 2001
From: Sasha Koshka <sashakoshka@tebibyte.media>
Date: Fri, 4 Aug 2023 21:59:52 -0400
Subject: [PATCH] Added dot selection visualization

---
 textbox.go | 72 +++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 61 insertions(+), 11 deletions(-)

diff --git a/textbox.go b/textbox.go
index 797714c..003ab6d 100644
--- a/textbox.go
+++ b/textbox.go
@@ -3,6 +3,7 @@ package x
 import "image"
 import "image/color"
 import "golang.org/x/image/font"
+import "golang.org/x/image/math/fixed"
 import "git.tebibyte.media/tomo/tomo"
 import "git.tebibyte.media/tomo/typeset"
 import "git.tebibyte.media/tomo/tomo/text"
@@ -24,6 +25,7 @@ type textBox struct {
 
 	selectable bool
 	dot        text.Dot
+	dotColor   color.Color
 	
 	drawer typeset.Drawer
 	
@@ -98,6 +100,14 @@ func (this *textBox) SetSelectable (selectable bool) {
 	this.selectable = selectable
 }
 
+func (this *textBox) SetDotColor (c color.Color) {
+	if this.dotColor == c { return }
+	this.dotColor = c
+	if !this.dot.Empty() {
+		this.invalidateDraw()
+	}
+}
+
 func (this *textBox) Select (dot text.Dot) {
 	if !this.selectable { return }
 	if this.dot == dot  { return }
@@ -144,24 +154,64 @@ func (this *textBox) Draw (can canvas.Canvas) {
 	this.drawer.Draw(can, this.textColor, this.textOffset())
 }
 
+func roundPt (point fixed.Point26_6) image.Point {
+	return image.Pt(point.X.Round(), point.Y.Round())
+}
+
+func fixPt (point image.Point) fixed.Point26_6 {
+	return fixed.P(point.X, point.Y)
+}
+
 func (this *textBox) drawDot (can canvas.Canvas) {
 	pen := can.Pen()
 	pen.Fill(color.Transparent)
 	pen.Stroke(this.textColor)
 	pen.StrokeWeight(1)
+
+	bounds  := this.InnerBounds()
+	metrics := this.face.Metrics()
+	dot     := this.dot.Canon()
+	start   := this.drawer.PositionAt(dot.Start).Add(fixPt(this.textOffset()))
+	end     := this.drawer.PositionAt(dot.End  ).Add(fixPt(this.textOffset()))
+	height  := this.drawer.LineHeight().Round()
+	ascent  := fixed.Point26_6 { Y: metrics.Descent }
+	descent := fixed.Point26_6 { Y: metrics.Ascent  }
 	
-	// TODO draw dot
-	if this.dot.Empty() {
-		metrics := this.face.Metrics()
-		position := this.drawer.PositionAt(this.dot.Start)
-		roundPos :=
-			image.Pt(position.X.Round(), position.Y.Round()).
-			Add(this.textOffset())
-		pen.Path (
-			roundPos.Add(image.Pt(0, metrics.Descent.Round())),
-			roundPos.Sub(image.Pt(0, metrics.Ascent.Round())))
-	} else {
+	switch {
+	case dot.Empty():
+		pen.Path(roundPt(start.Add(ascent)), roundPt(start.Sub(descent)))
 		
+	case start.Y == end.Y:
+		pen.Fill(this.dotColor)
+		pen.StrokeWeight(0)
+		pen.Rectangle(image.Rectangle {
+			Min: roundPt(start.Add(ascent)),
+			Max: roundPt(end.Sub(descent)),
+		})
+		
+	default:
+		pen.Fill(this.dotColor)
+		pen.StrokeWeight(0)
+		
+		rect := image.Rectangle {
+			Min: roundPt(start.Add(ascent)),
+			Max: roundPt(start.Sub(descent)),
+		}
+		rect.Max.X = bounds.Max.X
+		pen.Rectangle(rect)
+		if end.Y - start.Y > fixed.I(height) {
+			rect.Min.X = bounds.Min.X
+			rect.Min.Y = roundPt(start.Sub(descent)).Y + height
+			rect.Max.X = bounds.Max.X
+			rect.Max.Y = roundPt(end.Add(ascent)).Y - height
+			pen.Rectangle(rect)
+		}
+		rect = image.Rectangle {
+			Min: roundPt(end.Add(ascent)),
+			Max: roundPt(end.Sub(descent)),
+		}
+		rect.Min.X = bounds.Min.X
+		pen.Rectangle(rect)
 	}
 }