From ec8160ef40eef24ce660a740f28aeccdd2201df3 Mon Sep 17 00:00:00 2001
From: Jakub Sobon <jakub.sobon@elohim.sk>
Date: Mon, 18 Feb 2019 15:13:45 -0500
Subject: [PATCH] Don't zoom when only a single column was highlighted.

---
 widgets/linechart/zoom/zoom.go      | 10 ++++-
 widgets/linechart/zoom/zoom_test.go | 67 +++++++++++++++++++++++++++--
 2 files changed, 72 insertions(+), 5 deletions(-)

diff --git a/widgets/linechart/zoom/zoom.go b/widgets/linechart/zoom/zoom.go
index dc54771..73f4b58 100644
--- a/widgets/linechart/zoom/zoom.go
+++ b/widgets/linechart/zoom/zoom.go
@@ -201,8 +201,10 @@ func (t *Tracker) Mouse(m *terminalapi.Mouse) error {
 		if err != nil {
 			return err
 		}
-		t.zoomX = zoom
 		t.highlight.reset()
+		if zoom != nil {
+			t.zoomX = zoom
+		}
 
 	default:
 		t.highlight.reset()
@@ -382,7 +384,13 @@ func findCellPair(base *axes.XDetails, minCell, maxCell int) (*axes.Value, *axes
 }
 
 // zoomToHighlight zooms the base X axis according to the highlighted range.
+// Can return nil axis if the highlight didn't result in zooming.
 func zoomToHighlight(base *axes.XDetails, hr *Range, cvsAr image.Rectangle) (*axes.XDetails, error) {
+	// Only zoom if at least two columns were selected.
+	if got := numbers.Abs(hr.End - hr.Start); got < 2 {
+		return nil, nil
+	}
+
 	minL, maxL, err := findCellPair(base, hr.Start, hr.End-1)
 	if err != nil {
 		return nil, err
diff --git a/widgets/linechart/zoom/zoom_test.go b/widgets/linechart/zoom/zoom_test.go
index 483ba20..777fb8a 100644
--- a/widgets/linechart/zoom/zoom_test.go
+++ b/widgets/linechart/zoom/zoom_test.go
@@ -612,8 +612,14 @@ func TestTracker(t *testing.T) {
 				}); err != nil {
 					return err
 				}
-				return tr.Mouse(&terminalapi.Mouse{
+				if err := tr.Mouse(&terminalapi.Mouse{
 					Position: image.Point{6, 0},
+					Button:   mouse.ButtonLeft,
+				}); err != nil {
+					return err
+				}
+				return tr.Mouse(&terminalapi.Mouse{
+					Position: image.Point{2, 0},
 					Button:   mouse.ButtonRelease,
 				})
 			},
@@ -696,7 +702,7 @@ func TestTracker(t *testing.T) {
 			),
 		},
 		{
-			desc: "highlights of single row maximizes zoom",
+			desc: "highlights of single row doesn't zoom",
 			xp: &axes.XProperties{
 				Min:       0,
 				Max:       5,
@@ -716,6 +722,44 @@ func TestTracker(t *testing.T) {
 					Button:   mouse.ButtonRelease,
 				})
 
+			},
+			wantHighlight: false,
+			wantZoom: mustNewXDetails(
+				image.Rect(0, 0, 8, 8),
+				&axes.XProperties{
+					Min:       0,
+					Max:       5,
+					ReqYWidth: 2,
+				},
+			),
+		},
+		{
+			desc: "highlights of multiple rows maximizes zoom",
+			xp: &axes.XProperties{
+				Min:       0,
+				Max:       5,
+				ReqYWidth: 2,
+			},
+			cvsAr:   image.Rect(0, 0, 8, 8),
+			graphAr: image.Rect(2, 0, 8, 8),
+			mutate: func(tr *Tracker) error {
+				if err := tr.Mouse(&terminalapi.Mouse{
+					Position: image.Point{2, 0},
+					Button:   mouse.ButtonLeft,
+				}); err != nil {
+					return err
+				}
+				if err := tr.Mouse(&terminalapi.Mouse{
+					Position: image.Point{3, 0},
+					Button:   mouse.ButtonLeft,
+				}); err != nil {
+					return err
+				}
+				return tr.Mouse(&terminalapi.Mouse{
+					Position: image.Point{3, 0},
+					Button:   mouse.ButtonRelease,
+				})
+
 			},
 			wantHighlight: false,
 			wantZoom: mustNewXDetails(
@@ -904,7 +948,13 @@ func TestTracker(t *testing.T) {
 					return err
 				}
 				if err := tr.Mouse(&terminalapi.Mouse{
-					Position: image.Point{2, 0},
+					Position: image.Point{3, 0},
+					Button:   mouse.ButtonLeft,
+				}); err != nil {
+					return err
+				}
+				if err := tr.Mouse(&terminalapi.Mouse{
+					Position: image.Point{3, 0},
 					Button:   mouse.ButtonRelease,
 				}); err != nil {
 					return err
@@ -1279,13 +1329,22 @@ func TestZoomToHighlight(t *testing.T) {
 			wantErr: true,
 		},
 		{
-			desc:  "zooms to highlighted area",
+			desc:  "doesn't zoom when only one row selected",
 			cvsAr: image.Rect(0, 0, 4, 4),
 			baseP: &axes.XProperties{
 				Min: 0,
 				Max: 3,
 			},
 			hRange: &Range{Start: 1, End: 2},
+		},
+		{
+			desc:  "zooms to highlighted area",
+			cvsAr: image.Rect(0, 0, 4, 4),
+			baseP: &axes.XProperties{
+				Min: 0,
+				Max: 3,
+			},
+			hRange: &Range{Start: 1, End: 3},
 			wantP: &axes.XProperties{
 				Min: 1,
 				Max: 2,