From 92ab03510189875505ba97f1010ea85e8eebea31 Mon Sep 17 00:00:00 2001
From: vsariola <vsariola@users.noreply.github.com>
Date: Fri, 8 Jan 2021 15:36:11 +0200
Subject: [PATCH] feat(tracker): add row number markers to the left

---
 tracker/layout.go     | 13 +++++++++--
 tracker/rowmarkers.go | 53 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 64 insertions(+), 2 deletions(-)
 create mode 100644 tracker/rowmarkers.go

diff --git a/tracker/layout.go b/tracker/layout.go
index ae05126..0952f71 100644
--- a/tracker/layout.go
+++ b/tracker/layout.go
@@ -42,7 +42,7 @@ func (t *Tracker) Layout(gtx layout.Context) {
 }
 
 func (t *Tracker) layoutTracker(gtx layout.Context) layout.Dimensions {
-	flexTracks := make([]layout.FlexChild, len(t.song.Tracks))
+	flexTracks := make([]layout.FlexChild, len(t.song.Tracks)+1)
 	t.playRowPatMutex.RLock()
 	defer t.playRowPatMutex.RUnlock()
 
@@ -51,8 +51,17 @@ func (t *Tracker) layoutTracker(gtx layout.Context) layout.Dimensions {
 		playPat = -1
 	}
 
+	flexTracks[0] = layout.Rigid(Lowered(t.layoutRowMarkers(
+		len(t.song.Tracks[0].Patterns[0]),
+		len(t.song.Tracks[0].Sequence),
+		t.CursorRow,
+		t.DisplayPattern,
+		t.CursorColumn,
+		t.PlayRow,
+		playPat,
+	)))
 	for i, trk := range t.song.Tracks {
-		flexTracks[i] = layout.Rigid(Lowered(t.layoutTrack(
+		flexTracks[i+1] = layout.Rigid(Lowered(t.layoutTrack(
 			trk.Patterns,
 			trk.Sequence,
 			t.ActiveTrack == i,
diff --git a/tracker/rowmarkers.go b/tracker/rowmarkers.go
new file mode 100644
index 0000000..71e8e45
--- /dev/null
+++ b/tracker/rowmarkers.go
@@ -0,0 +1,53 @@
+package tracker
+
+import (
+	"fmt"
+	"image"
+	"strings"
+
+	"gioui.org/f32"
+	"gioui.org/layout"
+	"gioui.org/op"
+	"gioui.org/op/clip"
+	"gioui.org/op/paint"
+	"gioui.org/widget"
+)
+
+const rowMarkerWidth = 50
+
+func (t *Tracker) layoutRowMarkers(patternRows, sequenceLength, cursorRow, cursorPattern, cursorCol, playRow, playPattern int) layout.Widget {
+	return func(gtx layout.Context) layout.Dimensions {
+		gtx.Constraints.Min.X = rowMarkerWidth
+		gtx.Constraints.Max.X = rowMarkerWidth
+		paint.FillShape(gtx.Ops, inactiveTrackColor, clip.Rect{
+			Max: gtx.Constraints.Max,
+		}.Op())
+		defer op.Push(gtx.Ops).Pop()
+		clip.Rect{Max: gtx.Constraints.Max}.Add(gtx.Ops)
+		op.Offset(f32.Pt(0, float32(gtx.Constraints.Max.Y/2)-trackRowHeight)).Add(gtx.Ops)
+		cursorSongRow := cursorPattern*patternRows + cursorRow
+		playSongRow := playPattern*patternRows + playRow
+		op.Offset(f32.Pt(0, (-1*trackRowHeight)*float32(cursorSongRow))).Add(gtx.Ops)
+		for i := 0; i < sequenceLength; i++ {
+			for j := 0; j < patternRows; j++ {
+				songRow := i*patternRows + j
+				if songRow == playSongRow {
+					paint.FillShape(gtx.Ops, trackerPlayColor, clip.Rect{Max: image.Pt(trackWidth, trackRowHeight)}.Op())
+				}
+				if j == 0 {
+					paint.ColorOp{Color: trackerPatMarker}.Add(gtx.Ops)
+					widget.Label{}.Layout(gtx, textShaper, trackerFont, trackerFontSize, strings.ToUpper(fmt.Sprintf("%02x", i)))
+				}
+				if songRow == cursorSongRow {
+					paint.ColorOp{Color: trackerActiveTextColor}.Add(gtx.Ops)
+				} else {
+					paint.ColorOp{Color: trackerInactiveTextColor}.Add(gtx.Ops)
+				}
+				op.Offset(f32.Pt(rowMarkerWidth/2, 0)).Add(gtx.Ops)
+				widget.Label{}.Layout(gtx, textShaper, trackerFont, trackerFontSize, strings.ToUpper(fmt.Sprintf("%02x", j)))
+				op.Offset(f32.Pt(-rowMarkerWidth/2, trackRowHeight)).Add(gtx.Ops)
+			}
+		}
+		return layout.Dimensions{Size: gtx.Constraints.Max}
+	}
+}