From ff300988131d001634790bea3fa5219c42544d47 Mon Sep 17 00:00:00 2001
From: Nuno Cruces <ncruces@users.noreply.github.com>
Date: Mon, 12 Apr 2021 03:02:21 +0100
Subject: [PATCH] Calendar (unix).

---
 date.go      | 22 ++++++++++++++++++++++
 date_test.go | 38 ++++++++++++++++++++++++++++++++++++++
 date_unix.go | 34 ++++++++++++++++++++++++++++++++++
 zenity.go    |  3 +++
 4 files changed, 97 insertions(+)
 create mode 100644 date.go
 create mode 100644 date_test.go
 create mode 100644 date_unix.go

diff --git a/date.go b/date.go
new file mode 100644
index 0000000..4aedf9d
--- /dev/null
+++ b/date.go
@@ -0,0 +1,22 @@
+package zenity
+
+import (
+	"time"
+)
+
+// Calendar displays the calendar dialog.
+//
+// Returns zero on cancel.
+//
+// Valid options: Title, Width, Height, OKLabel, CancelLabel, ExtraButton,
+// Icon, Date.
+func Calendar(text string, options ...Option) (time.Time, error) {
+	return calendar(text, applyOptions(options))
+}
+
+// DefaultDate returns an Option to set the date.
+func DefaultDate(year int, month time.Month, day int) Option {
+	return funcOption(func(o *options) {
+		o.year, o.month, o.day = year, int(month), day
+	})
+}
diff --git a/date_test.go b/date_test.go
new file mode 100644
index 0000000..c5cccf5
--- /dev/null
+++ b/date_test.go
@@ -0,0 +1,38 @@
+package zenity_test
+
+import (
+	"context"
+	"errors"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/ncruces/zenity"
+)
+
+func ExampleCalendar() {
+	zenity.Calendar("Select a date from below:",
+		zenity.DefaultDate(2006, time.January, 1))
+	// Output:
+}
+
+func TestCalendarTimeout(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second/10)
+
+	_, err := zenity.Calendar("", zenity.Context(ctx))
+	if !os.IsTimeout(err) {
+		t.Error("did not timeout:", err)
+	}
+
+	cancel()
+}
+
+func TestCalendarCancel(t *testing.T) {
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	_, err := zenity.Calendar("", zenity.Context(ctx))
+	if !errors.Is(err, context.Canceled) {
+		t.Error("was not canceled:", err)
+	}
+}
diff --git a/date_unix.go b/date_unix.go
new file mode 100644
index 0000000..7197150
--- /dev/null
+++ b/date_unix.go
@@ -0,0 +1,34 @@
+// +build !windows,!darwin
+
+package zenity
+
+import (
+	"strconv"
+	"time"
+
+	"github.com/ncruces/zenity/internal/zenutil"
+)
+
+func calendar(text string, opts options) (time.Time, error) {
+	args := []string{"--calendar", "--text", text, "--date-format=%F"}
+	args = appendTitle(args, opts)
+	args = appendButtons(args, opts)
+	args = appendWidthHeight(args, opts)
+	args = appendIcon(args, opts)
+	if opts.day != 0 {
+		args = append(args, "--day", strconv.Itoa(opts.day))
+	}
+	if opts.month != 0 {
+		args = append(args, "--month", strconv.Itoa(opts.month))
+	}
+	if opts.year != 0 {
+		args = append(args, "--year", strconv.Itoa(opts.year))
+	}
+
+	out, err := zenutil.Run(opts.ctx, args)
+	str, ok, err := strResult(opts, out, err)
+	if ok {
+		return time.Parse("2006-01-02", str)
+	}
+	return time.Time{}, err
+}
diff --git a/zenity.go b/zenity.go
index b3314f0..1e33d34 100644
--- a/zenity.go
+++ b/zenity.go
@@ -53,6 +53,9 @@ type options struct {
 	disallowEmpty bool
 	defaultItems  []string
 
+	// Calendar options
+	year, month, day int
+
 	// File selection options
 	directory        bool
 	confirmOverwrite bool