Improve MultiplayerSynchronizer editor usability

* Add a button to add properties (which lets you select node and property)
* Add ability to drag properties and drop them to the editor.
* Made the editor transient (not always visible on the bottom) since its not needed most of the time.
* Added the ability to pin the editor, in case dragging properties from other nodes is desired.

2 files changed, 281 insertions, 6 deletions

diff --git a/editor/plugins/replication_editor_plugin.cpp b/editor/plugins/replication_editor_plugin.cpp
index 2a7b3c7a55..6992b5443b 100644
--- a/editor/plugins/replication_editor_plugin.cpp
+++ b/editor/plugins/replication_editor_plugin.cpp
@@ -37,6 +37,129 @@
 #include "scene/gui/tree.h"
 #include "scene/multiplayer/multiplayer_synchronizer.h"
 
+void ReplicationEditor::_pick_node_filter_text_changed(const String &p_newtext) {
+	TreeItem *root_item = pick_node->get_scene_tree()->get_scene_tree()->get_root();
+
+	Vector<Node *> select_candidates;
+	Node *to_select = nullptr;
+
+	String filter = pick_node->get_filter_line_edit()->get_text();
+
+	_pick_node_select_recursive(root_item, filter, select_candidates);
+
+	if (!select_candidates.is_empty()) {
+		for (int i = 0; i < select_candidates.size(); ++i) {
+			Node *candidate = select_candidates[i];
+
+			if (((String)candidate->get_name()).to_lower().begins_with(filter.to_lower())) {
+				to_select = candidate;
+				break;
+			}
+		}
+
+		if (!to_select) {
+			to_select = select_candidates[0];
+		}
+	}
+
+	pick_node->get_scene_tree()->set_selected(to_select);
+}
+
+void ReplicationEditor::_pick_node_select_recursive(TreeItem *p_item, const String &p_filter, Vector<Node *> &p_select_candidates) {
+	if (!p_item) {
+		return;
+	}
+
+	NodePath np = p_item->get_metadata(0);
+	Node *node = get_node(np);
+
+	if (!p_filter.is_empty() && ((String)node->get_name()).findn(p_filter) != -1) {
+		p_select_candidates.push_back(node);
+	}
+
+	TreeItem *c = p_item->get_first_child();
+
+	while (c) {
+		_pick_node_select_recursive(c, p_filter, p_select_candidates);
+		c = c->get_next();
+	}
+}
+
+void ReplicationEditor::_pick_node_filter_input(const Ref<InputEvent> &p_ie) {
+	Ref<InputEventKey> k = p_ie;
+
+	if (k.is_valid()) {
+		switch (k->get_keycode()) {
+			case Key::UP:
+			case Key::DOWN:
+			case Key::PAGEUP:
+			case Key::PAGEDOWN: {
+				pick_node->get_scene_tree()->get_scene_tree()->gui_input(k);
+				pick_node->get_filter_line_edit()->accept_event();
+			} break;
+			default:
+				break;
+		}
+	}
+}
+
+void ReplicationEditor::_pick_node_selected(NodePath p_path) {
+	Node *root = current->get_node(current->get_root_path());
+	ERR_FAIL_COND(!root);
+	Node *node = get_node(p_path);
+	ERR_FAIL_COND(!node);
+	NodePath path_to = root->get_path_to(node);
+	adding_node_path = path_to;
+	prop_selector->select_property_from_instance(node);
+}
+
+void ReplicationEditor::_pick_new_property() {
+	if (current == nullptr) {
+		EditorNode::get_singleton()->show_warning(TTR("Select a replicator node in order to pick a property to add to it."));
+		return;
+	}
+	Node *root = current->get_node(current->get_root_path());
+	if (!root) {
+		EditorNode::get_singleton()->show_warning(TTR("Not possible to add a new property to synchronize without a root."));
+		return;
+	}
+	pick_node->popup_scenetree_dialog();
+	pick_node->get_filter_line_edit()->clear();
+	pick_node->get_filter_line_edit()->grab_focus();
+}
+
+void ReplicationEditor::_add_sync_property(String p_path) {
+	config = current->get_replication_config();
+
+	if (config.is_valid() && config->has_property(p_path)) {
+		EditorNode::get_singleton()->show_warning(TTR("Property is already being synchronized."));
+		return;
+	}
+
+	UndoRedo *undo_redo = EditorNode::get_singleton()->get_undo_redo();
+	undo_redo->create_action(TTR("Add property to synchronizer"));
+
+	if (config.is_null()) {
+		config.instantiate();
+		current->set_replication_config(config);
+		undo_redo->add_do_method(current, "set_replication_config", config);
+		undo_redo->add_undo_method(current, "set_replication_config", Ref<SceneReplicationConfig>());
+		_update_config();
+	}
+
+	undo_redo->add_do_method(config.ptr(), "add_property", p_path);
+	undo_redo->add_undo_method(config.ptr(), "remove_property", p_path);
+	undo_redo->add_do_method(this, "_update_config");
+	undo_redo->add_undo_method(this, "_update_config");
+	undo_redo->commit_action();
+}
+
+void ReplicationEditor::_pick_node_property_selected(String p_name) {
+	String adding_prop_path = String(adding_node_path) + ":" + p_name;
+
+	_add_sync_property(adding_prop_path);
+}
+
 /// ReplicationEditor
 ReplicationEditor::ReplicationEditor() {
 	set_v_size_flags(SIZE_EXPAND_FILL);
@@ -56,16 +179,44 @@ ReplicationEditor::ReplicationEditor() {
 	vb->set_v_size_flags(SIZE_EXPAND_FILL);
 	add_child(vb);
 
+	pick_node = memnew(SceneTreeDialog);
+	add_child(pick_node);
+	pick_node->register_text_enter(pick_node->get_filter_line_edit());
+	pick_node->set_title(TTR("Pick a node to synchronize:"));
+	pick_node->connect("selected", callable_mp(this, &ReplicationEditor::_pick_node_selected));
+	pick_node->get_filter_line_edit()->connect("text_changed", callable_mp(this, &ReplicationEditor::_pick_node_filter_text_changed));
+	pick_node->get_filter_line_edit()->connect("gui_input", callable_mp(this, &ReplicationEditor::_pick_node_filter_input));
+
+	prop_selector = memnew(PropertySelector);
+	add_child(prop_selector);
+	prop_selector->connect("selected", callable_mp(this, &ReplicationEditor::_pick_node_property_selected));
+
 	HBoxContainer *hb = memnew(HBoxContainer);
 	vb->add_child(hb);
+
+	add_pick_button = memnew(Button);
+	add_pick_button->connect("pressed", callable_mp(this, &ReplicationEditor::_pick_new_property));
+	add_pick_button->set_text(TTR("Add property to sync.."));
+	hb->add_child(add_pick_button);
+	VSeparator *vs = memnew(VSeparator);
+	vs->set_custom_minimum_size(Size2(30 * EDSCALE, 0));
+	hb->add_child(vs);
+	hb->add_child(memnew(Label(TTR("Path:"))));
 	np_line_edit = memnew(LineEdit);
 	np_line_edit->set_placeholder(":property");
 	np_line_edit->set_h_size_flags(SIZE_EXPAND_FILL);
 	hb->add_child(np_line_edit);
-	add_button = memnew(Button);
-	add_button->connect("pressed", callable_mp(this, &ReplicationEditor::_add_pressed));
-	add_button->set_text(TTR("Add"));
-	hb->add_child(add_button);
+	add_from_path_button = memnew(Button);
+	add_from_path_button->connect("pressed", callable_mp(this, &ReplicationEditor::_add_pressed));
+	add_from_path_button->set_text(TTR("Add from path"));
+	hb->add_child(add_from_path_button);
+	vs = memnew(VSeparator);
+	vs->set_custom_minimum_size(Size2(30 * EDSCALE, 0));
+	hb->add_child(vs);
+	pin = memnew(Button);
+	pin->set_flat(true);
+	pin->set_toggle_mode(true);
+	hb->add_child(pin);
 
 	tree = memnew(Tree);
 	tree->set_hide_root(true);
@@ -85,19 +236,88 @@ ReplicationEditor::ReplicationEditor() {
 	tree->connect("item_edited", callable_mp(this, &ReplicationEditor::_tree_item_edited));
 	tree->set_v_size_flags(SIZE_EXPAND_FILL);
 	vb->add_child(tree);
+
+	drop_label = memnew(Label);
+	drop_label->set_text(TTR("Add properties using the buttons above or\ndrag them them from the inspector and drop them here."));
+	drop_label->set_horizontal_alignment(HORIZONTAL_ALIGNMENT_CENTER);
+	drop_label->set_vertical_alignment(VERTICAL_ALIGNMENT_CENTER);
+	tree->add_child(drop_label);
+	drop_label->set_anchors_and_offsets_preset(Control::PRESET_WIDE);
+
+	tree->set_drag_forwarding(this);
 }
 
 void ReplicationEditor::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("_update_config"), &ReplicationEditor::_update_config);
 	ClassDB::bind_method(D_METHOD("_update_checked", "property", "column", "checked"), &ReplicationEditor::_update_checked);
+	ClassDB::bind_method("_can_drop_data_fw", &ReplicationEditor::_can_drop_data_fw);
+	ClassDB::bind_method("_drop_data_fw", &ReplicationEditor::_drop_data_fw);
+
 	ADD_SIGNAL(MethodInfo("keying_changed"));
 }
 
+bool ReplicationEditor::_can_drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from) const {
+	Dictionary d = p_data;
+	if (!d.has("type")) {
+		return false;
+	}
+	String t = d["type"];
+	if (t != "obj_property") {
+		return false;
+	}
+	Object *obj = d["object"];
+	if (!obj) {
+		return false;
+	}
+	Node *node = Object::cast_to<Node>(obj);
+	if (!node) {
+		return false;
+	}
+
+	return true;
+}
+
+void ReplicationEditor::_drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from) {
+	if (current == nullptr) {
+		EditorNode::get_singleton()->show_warning(TTR("Select a replicator node in order to pick a property to add to it."));
+		return;
+	}
+	Node *root = current->get_node(current->get_root_path());
+	if (!root) {
+		EditorNode::get_singleton()->show_warning(TTR("Not possible to add a new property to synchronize without a root."));
+		return;
+	}
+
+	Dictionary d = p_data;
+	if (!d.has("type")) {
+		return;
+	}
+	String t = d["type"];
+	if (t != "obj_property") {
+		return;
+	}
+	Object *obj = d["object"];
+	if (!obj) {
+		return;
+	}
+	Node *node = Object::cast_to<Node>(obj);
+	if (!node) {
+		return;
+	}
+
+	String path = root->get_path_to(node);
+	path += ":" + String(d["property"]);
+
+	_add_sync_property(path);
+}
+
 void ReplicationEditor::_notification(int p_what) {
 	switch (p_what) {
 		case NOTIFICATION_ENTER_TREE:
 		case EditorSettings::NOTIFICATION_EDITOR_SETTINGS_CHANGED: {
 			add_theme_style_override("panel", EditorNode::get_singleton()->get_gui_base()->get_theme_stylebox(SNAME("panel"), SNAME("Panel")));
+			add_pick_button->set_icon(get_theme_icon(SNAME("Add"), SNAME("EditorIcons")));
+			pin->set_icon(get_theme_icon(SNAME("Pin"), SNAME("EditorIcons")));
 		} break;
 
 		case NOTIFICATION_VISIBILITY_CHANGED: {
@@ -236,11 +456,15 @@ void ReplicationEditor::_update_config() {
 	deleting = NodePath();
 	tree->clear();
 	tree->create_item();
+	drop_label->set_visible(true);
 	if (!config.is_valid()) {
 		update_keying();
 		return;
 	}
 	TypedArray<NodePath> props = config->get_properties();
+	if (props.size()) {
+		drop_label->set_visible(false);
+	}
 	for (int i = 0; i < props.size(); i++) {
 		const NodePath path = props[i];
 		_add_property(path, config->property_get_spawn(path), config->property_get_sync(path));
@@ -341,7 +565,9 @@ void ReplicationEditor::property_keyed(const String &p_property) {
 /// ReplicationEditorPlugin
 ReplicationEditorPlugin::ReplicationEditorPlugin() {
 	repl_editor = memnew(ReplicationEditor);
-	EditorNode::get_singleton()->add_bottom_panel_item(TTR("Replication"), repl_editor);
+	button = EditorNode::get_singleton()->add_bottom_panel_item(TTR("Replication"), repl_editor);
+	button->hide();
+	repl_editor->get_pin()->connect("pressed", callable_mp(this, &ReplicationEditorPlugin::_pinned));
 }
 
 ReplicationEditorPlugin::~ReplicationEditorPlugin() {
@@ -378,6 +604,17 @@ void ReplicationEditorPlugin::_node_removed(Node *p_node) {
 		if (repl_editor->is_visible_in_tree()) {
 			EditorNode::get_singleton()->hide_bottom_panel();
 		}
+		button->hide();
+		repl_editor->get_pin()->set_pressed(false);
+	}
+}
+
+void ReplicationEditorPlugin::_pinned() {
+	if (!repl_editor->get_pin()->is_pressed()) {
+		if (repl_editor->is_visible_in_tree()) {
+			EditorNode::get_singleton()->hide_bottom_panel();
+		}
+		button->hide();
 	}
 }
 
@@ -391,6 +628,14 @@ bool ReplicationEditorPlugin::handles(Object *p_object) const {
 
 void ReplicationEditorPlugin::make_visible(bool p_visible) {
 	if (p_visible) {
+		//editor->hide_animation_player_editors();
+		//editor->animation_panel_make_visible(true);
+		button->show();
 		EditorNode::get_singleton()->make_bottom_panel_item_visible(repl_editor);
+	} else if (!repl_editor->get_pin()->is_pressed()) {
+		if (repl_editor->is_visible_in_tree()) {
+			EditorNode::get_singleton()->hide_bottom_panel();
+		}
+		button->hide();
 	}
 }
diff --git a/editor/plugins/replication_editor_plugin.h b/editor/plugins/replication_editor_plugin.h
index 08e86d1617..b6de08a3a8 100644
--- a/editor/plugins/replication_editor_plugin.h
+++ b/editor/plugins/replication_editor_plugin.h
@@ -34,6 +34,10 @@
 #include "editor/editor_plugin.h"
 #include "scene/resources/scene_replication_config.h"
 
+#include "editor/editor_spin_slider.h"
+#include "editor/property_editor.h"
+#include "editor/property_selector.h"
+
 class ConfirmationDialog;
 class MultiplayerSynchronizer;
 class Tree;
@@ -46,14 +50,23 @@ private:
 
 	AcceptDialog *error_dialog = nullptr;
 	ConfirmationDialog *delete_dialog = nullptr;
-	Button *add_button = nullptr;
+	Button *add_pick_button = nullptr;
+	Button *add_from_path_button = nullptr;
 	LineEdit *np_line_edit = nullptr;
 
+	Label *drop_label = nullptr;
+
 	Ref<SceneReplicationConfig> config;
 	NodePath deleting;
 	Tree *tree = nullptr;
 	bool keying = false;
 
+	PropertySelector *prop_selector = nullptr;
+	SceneTreeDialog *pick_node = nullptr;
+	NodePath adding_node_path;
+
+	Button *pin = nullptr;
+
 	Ref<Texture2D> _get_class_icon(const Node *p_node);
 
 	void _add_pressed();
@@ -64,6 +77,19 @@ private:
 	void _dialog_closed(bool p_confirmed);
 	void _add_property(const NodePath &p_property, bool p_spawn = true, bool p_sync = true);
 
+	void _pick_node_filter_text_changed(const String &p_newtext);
+	void _pick_node_select_recursive(TreeItem *p_item, const String &p_filter, Vector<Node *> &p_select_candidates);
+	void _pick_node_filter_input(const Ref<InputEvent> &p_ie);
+	void _pick_node_selected(NodePath p_path);
+
+	void _pick_new_property();
+	void _pick_node_property_selected(String p_name);
+
+	bool _can_drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from) const;
+	void _drop_data_fw(const Point2 &p_point, const Variant &p_data, Control *p_from);
+
+	void _add_sync_property(String p_path);
+
 protected:
 	static void _bind_methods();
 
@@ -76,6 +102,7 @@ public:
 	MultiplayerSynchronizer *get_current() const { return current; }
 	void property_keyed(const String &p_property);
 
+	Button *get_pin() { return pin; }
 	ReplicationEditor();
 	~ReplicationEditor() {}
 };
@@ -84,12 +111,15 @@ class ReplicationEditorPlugin : public EditorPlugin {
 	GDCLASS(ReplicationEditorPlugin, EditorPlugin);
 
 private:
+	Button *button = nullptr;
 	ReplicationEditor *repl_editor = nullptr;
 
 	void _node_removed(Node *p_node);
 	void _keying_changed();
 	void _property_keyed(const String &p_keyed, const Variant &p_value, bool p_advance);
 
+	void _pinned();
+
 protected:
 	void _notification(int p_what);