Add auto-scrolling list example

_examples/autoscroll.go

@@ -0,0 +1,88 @@
+// Copyright 2017 Zack Guo <[email protected]>. All rights reserved.
+// Use of this source code is governed by a MIT license that can
+// be found in the LICENSE file.
+
+// +build ignore
+
+package main
+
+import (
+	"fmt"
+	"log"
+	"time"
+
+	ui "github.com/gizak/termui/v3"
+	"github.com/gizak/termui/v3/widgets"
+)
+
+func main() {
+	if err := ui.Init(); err != nil {
+		log.Fatalf("failed to initialize termui: %v", err)
+	}
+	defer ui.Close()
+
+	l := widgets.NewList()
+	l.Title = "List"
+	l.Rows = []string{
+		"[0] github.com/gizak/termui/v3",
+		"[1] [你好，世界](fg:blue)",
+		"[2] [こんにちは世界](fg:red)",
+	}
+	l.TextStyle = ui.NewStyle(ui.ColorYellow)
+	l.WrapText = false
+	l.SetRect(0, 0, 25, 8)
+
+	ui.Render(l)
+
+	previousKey := ""
+	tick := time.NewTicker(1 * time.Second)
+	uiEvents := ui.PollEvents()
+	counter := 3
+	for {
+		select {
+		case <-tick.C:
+			counter++
+			lenRows := len(l.Rows)
+			l.Rows = append(l.Rows, fmt.Sprintf("[%d] New element", counter))
+
+			if l.SelectedRow == lenRows-1 {
+				l.ScrollPageDown()
+			}
+			ui.Render(l)
+
+		case e := <-uiEvents:
+			switch e.ID {
+			case "q", "<C-c>":
+				return
+			case "j", "<Down>":
+				l.ScrollDown()
+			case "k", "<Up>":
+				l.ScrollUp()
+			case "<C-d>":
+				l.ScrollHalfPageDown()
+			case "<C-u>":
+				l.ScrollHalfPageUp()
+			case "<C-f>":
+				l.ScrollPageDown()
+			case "<C-b>":
+				l.ScrollPageUp()
+			case "g":
+				if previousKey == "g" {
+					l.ScrollTop()
+				}
+			case "<Home>":
+				l.ScrollTop()
+			case "G", "<End>":
+				l.ScrollBottom()
+			}
+
+			if previousKey == "g" {
+				previousKey = ""
+			} else {
+				previousKey = e.ID
+			}
+
+			ui.Render(l)
+		}
+	}
+}