From c1256862160b2023b92701e1a2a5d56147603baf Mon Sep 17 00:00:00 2001
From: Artem Lavrenov <git@lavrenov.net>
Date: Thu, 29 Aug 2019 21:15:39 +0300
Subject: [PATCH] For mouse support in list widget need export TopRow for
 calculate SelectedRow under mouse cursor.

---
 _examples/list.go  | 15 +++++++++++++--
 v3/widgets/list.go | 24 ++++++++++++------------
 2 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/_examples/list.go b/_examples/list.go
index 06571912..23090434 100644
--- a/_examples/list.go
+++ b/_examples/list.go
@@ -46,9 +46,20 @@ func main() {
 		switch e.ID {
 		case "q", "<C-c>":
 			return
-		case "j", "<Down>":
+		case "<MouseLeft>":
+			payload := e.Payload.(ui.Mouse)
+			border := 0
+			if l.BorderTop {
+				border = 1
+			}
+			x0, y0 := l.Inner.Min.X, l.Inner.Min.Y
+			x1, y1 := l.Inner.Max.X, l.Inner.Max.Y
+			if x0 < payload.X && payload.X < x1 && y0 < payload.Y && payload.Y < y1 {
+				l.SelectedRow = payload.Y - l.Rectangle.Min.Y - border + l.TopRow
+			}
+		case "j", "<Down>", "<MouseWheelDown>":
 			l.ScrollDown()
-		case "k", "<Up>":
+		case "k", "<Up>", "<MouseWheelUp>":
 			l.ScrollUp()
 		case "<C-d>":
 			l.ScrollHalfPageDown()
diff --git a/v3/widgets/list.go b/v3/widgets/list.go
index a4a6cb1b..d833a170 100644
--- a/v3/widgets/list.go
+++ b/v3/widgets/list.go
@@ -18,7 +18,7 @@ type List struct {
 	WrapText         bool
 	TextStyle        Style
 	SelectedRow      int
-	topRow           int
+	TopRow           int
 	SelectedRowStyle Style
 }
 
@@ -36,14 +36,14 @@ func (self *List) Draw(buf *Buffer) {
 	point := self.Inner.Min
 
 	// adjusts view into widget
-	if self.SelectedRow >= self.Inner.Dy()+self.topRow {
-		self.topRow = self.SelectedRow - self.Inner.Dy() + 1
-	} else if self.SelectedRow < self.topRow {
-		self.topRow = self.SelectedRow
+	if self.SelectedRow >= self.Inner.Dy()+self.TopRow {
+		self.TopRow = self.SelectedRow - self.Inner.Dy() + 1
+	} else if self.SelectedRow < self.TopRow {
+		self.TopRow = self.SelectedRow
 	}
 
 	// draw rows
-	for row := self.topRow; row < len(self.Rows) && point.Y < self.Inner.Max.Y; row++ {
+	for row := self.TopRow; row < len(self.Rows) && point.Y < self.Inner.Max.Y; row++ {
 		cells := ParseStyles(self.Rows[row], self.TextStyle)
 		if self.WrapText {
 			cells = WrapCells(cells, uint(self.Inner.Dx()))
@@ -69,7 +69,7 @@ func (self *List) Draw(buf *Buffer) {
 	}
 
 	// draw UP_ARROW if needed
-	if self.topRow > 0 {
+	if self.TopRow > 0 {
 		buf.SetCell(
 			NewCell(UP_ARROW, NewStyle(ColorWhite)),
 			image.Pt(self.Inner.Max.X-1, self.Inner.Min.Y),
@@ -77,7 +77,7 @@ func (self *List) Draw(buf *Buffer) {
 	}
 
 	// draw DOWN_ARROW if needed
-	if len(self.Rows) > int(self.topRow)+self.Inner.Dy() {
+	if len(self.Rows) > int(self.TopRow)+self.Inner.Dy() {
 		buf.SetCell(
 			NewCell(DOWN_ARROW, NewStyle(ColorWhite)),
 			image.Pt(self.Inner.Max.X-1, self.Inner.Max.Y-1),
@@ -86,8 +86,8 @@ func (self *List) Draw(buf *Buffer) {
 }
 
 // ScrollAmount scrolls by amount given. If amount is < 0, then scroll up.
-// There is no need to set self.topRow, as this will be set automatically when drawn,
-// since if the selected item is off screen then the topRow variable will change accordingly.
+// There is no need to set self.TopRow, as this will be set automatically when drawn,
+// since if the selected item is off screen then the TopRow variable will change accordingly.
 func (self *List) ScrollAmount(amount int) {
 	if len(self.Rows)-int(self.SelectedRow) <= amount {
 		self.SelectedRow = len(self.Rows) - 1
@@ -108,8 +108,8 @@ func (self *List) ScrollDown() {
 
 func (self *List) ScrollPageUp() {
 	// If an item is selected below top row, then go to the top row.
-	if self.SelectedRow > self.topRow {
-		self.SelectedRow = self.topRow
+	if self.SelectedRow > self.TopRow {
+		self.SelectedRow = self.TopRow
 	} else {
 		self.ScrollAmount(-self.Inner.Dy())
 	}