From 415ceee46b6ef0870b32de98991286f6c1fa5a5b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6ran=20Karl?=
 <3951388+JoeKar@users.noreply.github.com>
Date: Fri, 13 Oct 2023 01:56:16 +0200
Subject: [PATCH] plugin: Add new `onBufferOptionChanged` callback

This can become handy in the moment a plugin needs to react on e.g. changed
file type.
---
 internal/buffer/settings.go | 11 ++++++++++-
 runtime/help/plugins.md     |  4 ++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/internal/buffer/settings.go b/internal/buffer/settings.go
index 838df4a5..3bb3d0c0 100644
--- a/internal/buffer/settings.go
+++ b/internal/buffer/settings.go
@@ -5,7 +5,9 @@ import (
 	"reflect"
 
 	"github.com/zyedidia/micro/v2/internal/config"
+	ulua "github.com/zyedidia/micro/v2/internal/lua"
 	"github.com/zyedidia/micro/v2/internal/screen"
+	luar "layeh.com/gopher-luar"
 )
 
 func (b *Buffer) ReloadSettings(reloadFiletype bool) {
@@ -46,7 +48,8 @@ func (b *Buffer) ReloadSettings(reloadFiletype bool) {
 }
 
 func (b *Buffer) DoSetOptionNative(option string, nativeValue interface{}) {
-	if reflect.DeepEqual(b.Settings[option], nativeValue) {
+	oldValue := b.Settings[option]
+	if reflect.DeepEqual(oldValue, nativeValue) {
 		return
 	}
 
@@ -117,6 +120,12 @@ func (b *Buffer) DoSetOptionNative(option string, nativeValue interface{}) {
 	if b.OptionCallback != nil {
 		b.OptionCallback(option, nativeValue)
 	}
+
+	if err := config.RunPluginFn("onBufferOptionChanged",
+		luar.New(ulua.L, b), luar.New(ulua.L, option),
+		luar.New(ulua.L, oldValue), luar.New(ulua.L, nativeValue)); err != nil {
+		screen.TermMessage(err)
+	}
 }
 
 func (b *Buffer) SetOptionNative(option string, nativeValue interface{}) error {
diff --git a/runtime/help/plugins.md b/runtime/help/plugins.md
index fbab6469..5d4830fb 100644
--- a/runtime/help/plugins.md
+++ b/runtime/help/plugins.md
@@ -62,6 +62,10 @@ that micro defines:
 * `onBufferOpen(buf)`: runs when a buffer is opened. The input contains
    the buffer object.
 
+* `onBufferOptionChanged(buf, option, old, new)`: runs when an option of the
+   buffer has changed. The input contains the buffer object, the option name,
+   the old and the new value.
+
 * `onBufPaneOpen(bufpane)`: runs when a bufpane is opened. The input
    contains the bufpane object.