From ce18e928813526e59462e391c09e868c62facb42 Mon Sep 17 00:00:00 2001
From: Koni Marti <koni.marti@gmail.com>
Date: Mon, 18 Apr 2022 16:06:27 +0200
Subject: statusline: refactor to make it more customizable

Refactor statusline by clearly separating the rendering part from the
text display. Use printf-like format string for statusline
customization.

Document printf-like format string to customize the statusline.

Allow to completely mute the statusline (except for push notifications)
with a format specifier.

Provide a display mode with unicode icons for the status elements.

Implements: https://todo.sr.ht/~rjarry/aerc/34
Signed-off-by: Koni Marti <koni.marti@gmail.com>
Acked-by: Robin Jarry <robin@jarry.cc>
---
 lib/statusline/renderer.go | 194 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 194 insertions(+)
 create mode 100644 lib/statusline/renderer.go

(limited to 'lib/statusline/renderer.go')

diff --git a/lib/statusline/renderer.go b/lib/statusline/renderer.go
new file mode 100644
index 00000000..2ab05dd9
--- /dev/null
+++ b/lib/statusline/renderer.go
@@ -0,0 +1,194 @@
+package statusline
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"unicode"
+
+	"github.com/mattn/go-runewidth"
+)
+
+type renderParams struct {
+	width int
+	sep   string
+	acct  *accountState
+	fldr  *folderState
+}
+
+type renderFunc func(r renderParams) string
+
+func newRenderer(renderFormat, textMode string) renderFunc {
+	var texter Texter
+	switch strings.ToLower(textMode) {
+	case "icon":
+		texter = &icon{}
+	default:
+		texter = &text{}
+	}
+
+	return renderer(texter, renderFormat)
+}
+
+func renderer(texter Texter, renderFormat string) renderFunc {
+	var leftFmt, rightFmt string
+	if idx := strings.Index(renderFormat, "%>"); idx < 0 {
+		leftFmt = renderFormat
+	} else {
+		leftFmt, rightFmt = renderFormat[:idx], strings.Replace(renderFormat[idx:], "%>", "", 1)
+	}
+
+	return func(r renderParams) string {
+		lfmtStr, largs, err := parseStatuslineFormat(leftFmt, texter, r)
+		if err != nil {
+			return err.Error()
+		}
+		rfmtStr, rargs, err := parseStatuslineFormat(rightFmt, texter, r)
+		if err != nil {
+			return err.Error()
+		}
+		leftText, rightText := fmt.Sprintf(lfmtStr, largs...), fmt.Sprintf(rfmtStr, rargs...)
+		return runewidth.FillRight(leftText, r.width-len(rightText)-1) + rightText
+	}
+}
+
+func connectionInfo(acct *accountState, texter Texter) (conn string) {
+	if acct.ConnActivity != "" {
+		conn += acct.ConnActivity
+	} else {
+		if acct.Connected {
+			conn += texter.Connected()
+		} else {
+			conn += texter.Disconnected()
+		}
+	}
+	return
+}
+
+func contentInfo(acct *accountState, fldr *folderState, texter Texter) []string {
+	var status []string
+	if fldr.FilterActivity != "" {
+		status = append(status, fldr.FilterActivity)
+	} else {
+		if fldr.Filter != "" {
+			status = append(status, texter.FormatFilter(fldr.Filter))
+		}
+	}
+	if fldr.Search != "" {
+		status = append(status, texter.FormatSearch(fldr.Search))
+	}
+	return status
+}
+
+func trayInfo(acct *accountState, fldr *folderState, texter Texter) []string {
+	var tray []string
+	if fldr.Sorting {
+		tray = append(tray, texter.Sorting())
+	}
+	if fldr.Threading {
+		tray = append(tray, texter.Threading())
+	}
+	if acct.Passthrough {
+		tray = append(tray, texter.Passthrough())
+	}
+	return tray
+}
+
+func parseStatuslineFormat(format string, texter Texter, r renderParams) (string, []interface{}, error) {
+	retval := make([]byte, 0, len(format))
+	var args []interface{}
+	mute := false
+
+	var c rune
+	for i, ni := 0, 0; i < len(format); {
+		ni = strings.IndexByte(format[i:], '%')
+		if ni < 0 {
+			ni = len(format)
+			retval = append(retval, []byte(format[i:ni])...)
+			break
+		}
+		ni += i + 1
+		// Check for fmt flags
+		if ni == len(format) {
+			goto handle_end_error
+		}
+		c = rune(format[ni])
+		if c == '+' || c == '-' || c == '#' || c == ' ' || c == '0' {
+			ni++
+		}
+
+		// Check for precision and width
+		if ni == len(format) {
+			goto handle_end_error
+		}
+		c = rune(format[ni])
+		for unicode.IsDigit(c) {
+			ni++
+			c = rune(format[ni])
+		}
+		if c == '.' {
+			ni++
+			c = rune(format[ni])
+			for unicode.IsDigit(c) {
+				ni++
+				c = rune(format[ni])
+			}
+		}
+
+		retval = append(retval, []byte(format[i:ni])...)
+		// Get final format verb
+		if ni == len(format) {
+			goto handle_end_error
+		}
+		c = rune(format[ni])
+		switch c {
+		case '%':
+			retval = append(retval, '%')
+		case 'a':
+			retval = append(retval, 's')
+			args = append(args, r.acct.Name)
+		case 'c':
+			retval = append(retval, 's')
+			args = append(args, connectionInfo(r.acct, texter))
+		case 'd':
+			retval = append(retval, 's')
+			args = append(args, r.fldr.Name)
+		case 'm':
+			mute = true
+		case 'S':
+			var status []string
+			if conn := connectionInfo(r.acct, texter); conn != "" {
+				status = append(status, conn)
+			}
+
+			if r.acct.Connected {
+				status = append(status, contentInfo(r.acct, r.fldr, texter)...)
+			}
+			retval = append(retval, 's')
+			args = append(args, strings.Join(status, r.sep))
+		case 'T':
+			var tray []string
+			if r.acct.Connected {
+				tray = trayInfo(r.acct, r.fldr, texter)
+			}
+			retval = append(retval, 's')
+			args = append(args, strings.Join(tray, r.sep))
+		default:
+			// Just ignore it and print as is
+			// so %k in index format becomes %%k to Printf
+			retval = append(retval, '%')
+			retval = append(retval, byte(c))
+		}
+		i = ni + 1
+	}
+
+	if mute {
+		return "", nil, nil
+	}
+
+	return string(retval), args, nil
+
+handle_end_error:
+	return "", nil,
+		errors.New("reached end of string while parsing statusline format")
+}
-- 
cgit