add log panel to expanded widgets

cwidgets/expanded/logs.go

@@ -0,0 +1,80 @@
+package expanded
+
+import (
+	ui "github.com/gizak/termui"
+)
+
+type LogLines struct {
+	ts   []string
+	data []string
+}
+
+func NewLogLines(max int) *LogLines {
+	ll := &LogLines{
+		ts:   make([]string, max),
+		data: make([]string, max),
+	}
+	return ll
+}
+
+func (ll *LogLines) tail(n int) []string {
+	lines := make([]string, n)
+	for i := 0; i < n; i++ {
+		lines = append(lines, ll.data[len(ll.data)-i])
+	}
+	return lines
+}
+func (ll *LogLines) getLines(start, end int) []string {
+	if end < 0 {
+		return ll.data[start:]
+	}
+	return ll.data[start:end]
+}
+
+func (ll *LogLines) add(s string) {
+	if len(ll.data) == cap(ll.data) {
+		ll.data = append(ll.data[:0], ll.data[1:]...)
+		ll.ts = append(ll.ts[:0], ll.ts[1:]...)
+	}
+	ll.ts = append(ll.ts, "timestamp")
+	ll.data = append(ll.data, s)
+	log.Debugf("recorded log line: %v", s)
+}
+
+type Logs struct {
+	*ui.List
+	lines *LogLines
+}
+
+func NewLogs(stream chan string) *Logs {
+	p := ui.NewList()
+	p.Y = ui.TermHeight() / 2
+	p.X = 0
+	p.Height = ui.TermHeight() - p.Y
+	p.Width = ui.TermWidth()
+	//p.Overflow = "wrap"
+	p.ItemFgColor = ui.ThemeAttr("par.text.fg")
+	i := &Logs{p, NewLogLines(4098)}
+	go func() {
+		for line := range stream {
+			i.lines.add(line)
+			ui.Render(i)
+		}
+	}()
+	return i
+}
+
+func (w *Logs) Align() {
+	w.X = colWidth[0]
+	w.List.Align()
+}
+
+func (w *Logs) Buffer() ui.Buffer {
+	maxLines := w.Height - 2
+	offset := len(w.lines.data) - maxLines
+	w.Items = w.lines.getLines(offset, -1)
+	return w.List.Buffer()
+}
+
+// number of rows a line will occupy at current panel width
+func (w *Logs) lineHeight(s string) int { return (len(s) / w.InnerWidth()) + 1 }