Added ability to get a list of project settings changed.

Author: MauriceButler

core/config/project_settings.cpp

@@ -277,6 +277,12 @@ String ProjectSettings::globalize_path(const String &p_path) const {
 bool ProjectSettings::_set(const StringName &p_name, const Variant &p_value) {
 	_THREAD_SAFE_METHOD_
 
+	// Capture old value before making changes
+	Variant old_value;
+	if (props.has(p_name)) {
+		old_value = props[p_name].variant;
+	}
+
 	if (p_value.get_type() == Variant::NIL) {
 		props.erase(p_name);
 		if (p_name.operator String().begins_with("autoload/")) {
@@ -298,7 +304,10 @@ bool ProjectSettings::_set(const StringName &p_name, const Variant &p_value) {
 			}
 
 			_version++;
-			_queue_changed();
+
+			if (old_value != p_value) {
+				_queue_changed(p_name);
+			}
 			return true;
 		}
 
@@ -344,7 +353,10 @@ bool ProjectSettings::_set(const StringName &p_name, const Variant &p_value) {
 	}
 
 	_version++;
-	_queue_changed();
+
+	if (old_value != p_value) {
+		_queue_changed(p_name);
+	}
 	return true;
 }
 
@@ -528,12 +540,32 @@ void ProjectSettings::_queue_changed() {
 	callable_mp(this, &ProjectSettings::_emit_changed).call_deferred();
 }
 
+void ProjectSettings::_queue_changed(const StringName &p_name) {
+	if (!MessageQueue::get_singleton() || MessageQueue::get_singleton()->get_max_buffer_usage() == 0) {
+		return;
+	}
+
+	// Track this setting as changed
+	changed_settings.insert(p_name);
+
+	// Only queue the deferred call once per frame
+	if (!is_changed) {
+		is_changed = true;
+		callable_mp(this, &ProjectSettings::_emit_changed).call_deferred();
+	}
+}
+
 void ProjectSettings::_emit_changed() {
 	if (!is_changed) {
 		return;
 	}
 	is_changed = false;
+
+	// Emit the general settings_changed signal to indicate changes are complete.
 	emit_signal("settings_changed");
+
+	// Clear the changed settings after emitting the signal
+	clear_changed_settings();
 }
 
 bool ProjectSettings::load_resource_pack(const String &p_pack, bool p_replace_files, int p_offset) {
@@ -1313,6 +1345,31 @@ Variant ProjectSettings::get_setting(const String &p_setting, const Variant &p_d
 	}
 }
 
+PackedStringArray ProjectSettings::get_changed_settings() const {
+	PackedStringArray arr;
+	for (const String &setting : changed_settings) {
+		arr.push_back(setting);
+	}
+	return arr;
+}
+
+bool ProjectSettings::check_changed_settings_in_group(const String &p_setting_prefix) const {
+	for (const String &setting : changed_settings) {
+		if (setting.begins_with(p_setting_prefix)) {
+			return true;
+		}
+	}
+	return false;
+}
+
+void ProjectSettings::mark_setting_changed(const String &p_setting) {
+	changed_settings.insert(p_setting);
+}
+
+void ProjectSettings::clear_changed_settings() {
+	changed_settings.clear();
+}
+
 void ProjectSettings::refresh_global_class_list() {
 	// This is called after mounting a new PCK file to pick up class changes.
 	is_global_class_list_loaded = false; // Make sure we read from the freshly mounted PCK.
@@ -1509,6 +1566,12 @@ void ProjectSettings::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("save_custom", "file"), &ProjectSettings::_save_custom_bnd);
 
+	// Change tracking methods
+	ClassDB::bind_method(D_METHOD("get_changed_settings"), &ProjectSettings::get_changed_settings);
+	ClassDB::bind_method(D_METHOD("check_changed_settings_in_group", "setting_prefix"), &ProjectSettings::check_changed_settings_in_group);
+	ClassDB::bind_method(D_METHOD("mark_setting_changed", "setting"), &ProjectSettings::mark_setting_changed);
+	ClassDB::bind_method(D_METHOD("clear_changed_settings"), &ProjectSettings::clear_changed_settings);
+
 	ADD_SIGNAL(MethodInfo("settings_changed"));
 }
 

core/config/project_settings.h

@@ -46,6 +46,9 @@ class ProjectSettings : public Object {
 	// and will always detect the initial project settings as a "change".
 	uint32_t _version = 1;
 
+	// Track changed settings for get_changed_settings functionality
+	HashSet<String> changed_settings;
+
 public:
 	typedef HashMap<String, Variant> CustomMap;
 	static inline const String PROJECT_DATA_DIR_NAME_SUFFIX = "godot";
@@ -119,6 +122,7 @@ class ProjectSettings : public Object {
 	bool _property_get_revert(const StringName &p_name, Variant &r_property) const;
 
 	void _queue_changed();
+	void _queue_changed(const StringName &p_name);
 	void _emit_changed();
 
 	static inline ProjectSettings *singleton = nullptr;
@@ -209,6 +213,12 @@ class ProjectSettings : public Object {
 
 	bool has_custom_feature(const String &p_feature) const;
 
+	// Change tracking methods
+	PackedStringArray get_changed_settings() const;
+	bool check_changed_settings_in_group(const String &p_setting_prefix) const;
+	void mark_setting_changed(const String &p_setting);
+	void clear_changed_settings();
+
 	const HashMap<StringName, AutoloadInfo> &get_autoload_list() const;
 	void add_autoload(const AutoloadInfo &p_autoload);
 	void remove_autoload(const StringName &p_autoload);

doc/classes/ProjectSettings.xml

@@ -54,13 +54,32 @@
 				[b]Note:[/b] Setting [code]"usage"[/code] for the property is not supported. Use [method set_as_basic], [method set_restart_if_changed], and [method set_as_internal] to modify usage flags.
 			</description>
 		</method>
+		<method name="check_changed_settings_in_group" qualifiers="const">
+			<return type="bool" />
+			<param index="0" name="setting_prefix" type="String" />
+			<description>
+				Checks if any settings with the prefix [param setting_prefix] exist in the set of changed settings. See also [method get_changed_settings].
+			</description>
+		</method>
 		<method name="clear">
 			<return type="void" />
 			<param index="0" name="name" type="String" />
 			<description>
 				Clears the whole configuration (not recommended, may break things).
 			</description>
 		</method>
+		<method name="clear_changed_settings">
+			<return type="void" />
+			<description>
+				Clears the list of changed settings. Note that internally [code]changed_settings[/code] is cleared after a successful save, so generally the most appropriate place to use this method is when processing [signal settings_changed].
+			</description>
+		</method>
+		<method name="get_changed_settings" qualifiers="const">
+			<return type="PackedStringArray" />
+			<description>
+				Gets an array of the settings which have been changed since the last save. Note that internally [code]changed_settings[/code] is cleared after a successful save, so generally the most appropriate place to use this method is when processing [signal settings_changed].
+			</description>
+		</method>
 		<method name="get_global_class_list">
 			<return type="Dictionary[]" />
 			<description>
@@ -172,6 +191,13 @@
 				Returns the localized path (starting with [code]res://[/code]) corresponding to the absolute, native OS [param path]. See also [method globalize_path].
 			</description>
 		</method>
+		<method name="mark_setting_changed">
+			<return type="void" />
+			<param index="0" name="setting" type="String" />
+			<description>
+				Marks the passed project setting as being changed, see [method get_changed_settings]. Only settings which exist (see [method has_setting]) will be accepted.
+			</description>
+		</method>
 		<method name="save">
 			<return type="int" enum="Error" />
 			<description>