Drag to rearrange Tabs and TabContainer

6 files changed, 347 insertions, 4 deletions

diff --git a/editor/editor_node.cpp b/editor/editor_node.cpp
index 141769b16a..c31bec9a1b 100644
--- a/editor/editor_node.cpp
+++ b/editor/editor_node.cpp
@@ -3892,6 +3892,53 @@ void EditorNode::_update_dock_slots_visibility() {
 	}
 }
 
+void EditorNode::_dock_tab_changed(int p_tab) {
+
+	// update visibility but dont set current tab
+	VSplitContainer *splits[DOCK_SLOT_MAX / 2] = {
+		left_l_vsplit,
+		left_r_vsplit,
+		right_l_vsplit,
+		right_r_vsplit,
+	};
+
+	if (!docks_visible) {
+
+		for (int i = 0; i < DOCK_SLOT_MAX; i++) {
+			dock_slot[i]->hide();
+		}
+
+		for (int i = 0; i < DOCK_SLOT_MAX / 2; i++) {
+			splits[i]->hide();
+		}
+
+		right_hsplit->hide();
+		bottom_panel->hide();
+	} else {
+		for (int i = 0; i < DOCK_SLOT_MAX; i++) {
+
+			if (dock_slot[i]->get_tab_count())
+				dock_slot[i]->show();
+			else
+				dock_slot[i]->hide();
+		}
+
+		for (int i = 0; i < DOCK_SLOT_MAX / 2; i++) {
+			bool in_use = dock_slot[i * 2 + 0]->get_tab_count() || dock_slot[i * 2 + 1]->get_tab_count();
+			if (in_use)
+				splits[i]->show();
+			else
+				splits[i]->hide();
+		}
+		bottom_panel->show();
+
+		if (right_l_vsplit->is_visible() || right_r_vsplit->is_visible())
+			right_hsplit->show();
+		else
+			right_hsplit->hide();
+	}
+}
+
 void EditorNode::_load_docks_from_config(Ref<ConfigFile> p_layout, const String &p_section) {
 
 	for (int i = 0; i < DOCK_SLOT_MAX; i++) {
@@ -4762,6 +4809,7 @@ void EditorNode::_bind_methods() {
 	ClassDB::bind_method("_dock_popup_exit", &EditorNode::_dock_popup_exit);
 	ClassDB::bind_method("_dock_move_left", &EditorNode::_dock_move_left);
 	ClassDB::bind_method("_dock_move_right", &EditorNode::_dock_move_right);
+	ClassDB::bind_method("_dock_tab_changed", &EditorNode::_dock_tab_changed);
 
 	ClassDB::bind_method("_layout_menu_option", &EditorNode::_layout_menu_option);
 
@@ -5121,6 +5169,9 @@ EditorNode::EditorNode() {
 		dock_slot[i]->set_popup(dock_select_popup);
 		dock_slot[i]->connect("pre_popup_pressed", this, "_dock_pre_popup", varray(i));
 		dock_slot[i]->set_tab_align(TabContainer::ALIGN_LEFT);
+		dock_slot[i]->set_drag_to_rearrange_enabled(true);
+		dock_slot[i]->set_tabs_rearrange_group(1);
+		dock_slot[i]->connect("tab_changed", this, "_dock_tab_changed");
 	}
 
 	dock_drag_timer = memnew(Timer);
@@ -5158,6 +5209,7 @@ EditorNode::EditorNode() {
 	scene_tabs->set_tab_align(Tabs::ALIGN_LEFT);
 	scene_tabs->set_tab_close_display_policy((bool(EDITOR_DEF("interface/scene_tabs/always_show_close_button", false)) ? Tabs::CLOSE_BUTTON_SHOW_ALWAYS : Tabs::CLOSE_BUTTON_SHOW_ACTIVE_ONLY));
 	scene_tabs->set_min_width(int(EDITOR_DEF("interface/scene_tabs/minimum_width", 50)) * EDSCALE);
+	scene_tabs->set_drag_to_rearrange_enabled(true);
 	scene_tabs->connect("tab_changed", this, "_scene_tab_changed");
 	scene_tabs->connect("right_button_pressed", this, "_scene_tab_script_edited");
 	scene_tabs->connect("tab_close", this, "_scene_tab_closed");
diff --git a/editor/editor_node.h b/editor/editor_node.h
index 90bebffca6..f774fa0a2e 100644
--- a/editor/editor_node.h
+++ b/editor/editor_node.h
@@ -569,6 +569,7 @@ private:
 	void _save_docks_to_config(Ref<ConfigFile> p_layout, const String &p_section);
 	void _load_docks_from_config(Ref<ConfigFile> p_layout, const String &p_section);
 	void _update_dock_slots_visibility();
+	void _dock_tab_changed(int p_tab);
 
 	bool restoring_scenes;
 	void _save_open_scenes_to_config(Ref<ConfigFile> p_layout, const String &p_section);
diff --git a/scene/gui/tab_container.cpp b/scene/gui/tab_container.cpp
index 6e85ce5eb4..0363dd44c2 100644
--- a/scene/gui/tab_container.cpp
+++ b/scene/gui/tab_container.cpp
@@ -31,6 +31,9 @@
 #include "tab_container.h"
 
 #include "message_queue.h"
+#include "scene/gui/box_container.h"
+#include "scene/gui/label.h"
+#include "scene/gui/texture_rect.h"
 
 int TabContainer::_get_top_margin() const {
 
@@ -492,6 +495,141 @@ void TabContainer::_update_current_tab() {
 		set_current_tab(current);
 }
 
+Variant TabContainer::get_drag_data(const Point2 &p_point) {
+
+	if (!drag_to_rearrange_enabled)
+		return Variant();
+
+	int tab_over = get_tab_idx_at_point(p_point);
+
+	if (tab_over < 0)
+		return Variant();
+
+	HBoxContainer *drag_preview = memnew(HBoxContainer);
+
+	Ref<Texture> icon = get_tab_icon(tab_over);
+	if (!icon.is_null()) {
+		TextureRect *tf = memnew(TextureRect);
+		tf->set_texture(icon);
+		drag_preview->add_child(tf);
+	}
+	Label *label = memnew(Label(get_tab_title(tab_over)));
+	drag_preview->add_child(label);
+	set_drag_preview(drag_preview);
+
+	Dictionary drag_data;
+	drag_data["type"] = "tabc_element";
+	drag_data["tabc_element"] = tab_over;
+	drag_data["from_path"] = get_path();
+	return drag_data;
+}
+
+bool TabContainer::can_drop_data(const Point2 &p_point, const Variant &p_data) const {
+
+	if (!drag_to_rearrange_enabled)
+		return false;
+
+	Dictionary d = p_data;
+	if (!d.has("type"))
+		return false;
+
+	if (String(d["type"]) == "tabc_element") {
+
+		NodePath from_path = d["from_path"];
+		NodePath to_path = get_path();
+		if (from_path == to_path) {
+			return true;
+		} else if (get_tabs_rearrange_group() != -1) {
+			// drag and drop between other TabContainers
+			Node *from_node = get_node(from_path);
+			TabContainer *from_tabc = Object::cast_to<TabContainer>(from_node);
+			if (from_tabc && from_tabc->get_tabs_rearrange_group() == get_tabs_rearrange_group()) {
+				return true;
+			}
+		}
+	}
+	return false;
+}
+
+void TabContainer::drop_data(const Point2 &p_point, const Variant &p_data) {
+
+	if (!drag_to_rearrange_enabled)
+		return;
+
+	int hover_now = get_tab_idx_at_point(p_point);
+
+	Dictionary d = p_data;
+	if (!d.has("type"))
+		return;
+
+	if (String(d["type"]) == "tabc_element") {
+
+		int tab_from_id = d["tabc_element"];
+		NodePath from_path = d["from_path"];
+		NodePath to_path = get_path();
+		if (from_path == to_path) {
+			if (hover_now < 0)
+				hover_now = get_tab_count() - 1;
+			move_child(get_tab_control(tab_from_id), hover_now);
+			set_current_tab(hover_now);
+		} else if (get_tabs_rearrange_group() != -1) {
+			// drag and drop between TabContainers
+			Node *from_node = get_node(from_path);
+			TabContainer *from_tabc = Object::cast_to<TabContainer>(from_node);
+			if (from_tabc && from_tabc->get_tabs_rearrange_group() == get_tabs_rearrange_group()) {
+				Control *moving_tabc = from_tabc->get_tab_control(tab_from_id);
+				from_tabc->remove_child(moving_tabc);
+				add_child(moving_tabc);
+				if (hover_now < 0)
+					hover_now = get_tab_count() - 1;
+				move_child(moving_tabc, hover_now);
+				set_current_tab(hover_now);
+				emit_signal("tab_changed", hover_now);
+			}
+		}
+	}
+	update();
+}
+
+int TabContainer::get_tab_idx_at_point(const Point2 &p_point) const {
+
+	if (get_tab_count() == 0)
+		return -1;
+
+	// must be on tabs in the tab header area.
+	if (p_point.x < tabs_ofs_cache || p_point.y > _get_top_margin())
+		return -1;
+
+	Size2 size = get_size();
+	int right_ofs = 0;
+
+	if (popup) {
+		Ref<Texture> menu = get_icon("menu");
+		right_ofs += menu->get_width();
+	}
+	if (buttons_visible_cache) {
+		Ref<Texture> increment = get_icon("increment");
+		Ref<Texture> decrement = get_icon("decrement");
+		right_ofs += increment->get_width() + decrement->get_width();
+	}
+	if (p_point.x > size.width - right_ofs) {
+		return -1;
+	}
+
+	// get the tab at the point
+	Vector<Control *> tabs = _get_tabs();
+	int px = p_point.x;
+	px -= tabs_ofs_cache;
+	for (int i = first_tab_cache; i <= last_tab_cache; i++) {
+		int tab_width = _get_tab_width(i);
+		if (px < tab_width) {
+			return i;
+		}
+		px -= tab_width;
+	}
+	return -1;
+}
+
 void TabContainer::set_tab_align(TabAlign p_align) {
 
 	ERR_FAIL_INDEX(p_align, 3);
@@ -500,6 +638,7 @@ void TabContainer::set_tab_align(TabAlign p_align) {
 
 	_change_notify("tab_align");
 }
+
 TabContainer::TabAlign TabContainer::get_tab_align() const {
 
 	return align;
@@ -643,6 +782,21 @@ Popup *TabContainer::get_popup() const {
 	return popup;
 }
 
+void TabContainer::set_drag_to_rearrange_enabled(bool p_enabled) {
+	drag_to_rearrange_enabled = p_enabled;
+}
+
+bool TabContainer::get_drag_to_rearrange_enabled() const {
+	return drag_to_rearrange_enabled;
+}
+void TabContainer::set_tabs_rearrange_group(int p_group_id) {
+	tabs_rearrange_group = p_group_id;
+}
+
+int TabContainer::get_tabs_rearrange_group() const {
+	return tabs_rearrange_group;
+}
+
 void TabContainer::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("_gui_input"), &TabContainer::_gui_input);
@@ -664,6 +818,10 @@ void TabContainer::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_tab_disabled", "tab_idx"), &TabContainer::get_tab_disabled);
 	ClassDB::bind_method(D_METHOD("set_popup", "popup"), &TabContainer::set_popup);
 	ClassDB::bind_method(D_METHOD("get_popup"), &TabContainer::get_popup);
+	ClassDB::bind_method(D_METHOD("set_drag_to_rearrange_enabled", "enabled"), &TabContainer::set_drag_to_rearrange_enabled);
+	ClassDB::bind_method(D_METHOD("get_drag_to_rearrange_enabled"), &TabContainer::get_drag_to_rearrange_enabled);
+	ClassDB::bind_method(D_METHOD("set_tabs_rearrange_group", "group_id"), &TabContainer::set_tabs_rearrange_group);
+	ClassDB::bind_method(D_METHOD("get_tabs_rearrange_group"), &TabContainer::get_tabs_rearrange_group);
 
 	ClassDB::bind_method(D_METHOD("_child_renamed_callback"), &TabContainer::_child_renamed_callback);
 	ClassDB::bind_method(D_METHOD("_on_theme_changed"), &TabContainer::_on_theme_changed);
@@ -676,6 +834,7 @@ void TabContainer::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "tab_align", PROPERTY_HINT_ENUM, "Left,Center,Right"), "set_tab_align", "get_tab_align");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "current_tab", PROPERTY_HINT_RANGE, "-1,4096,1", PROPERTY_USAGE_EDITOR), "set_current_tab", "get_current_tab");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "tabs_visible"), "set_tabs_visible", "are_tabs_visible");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "drag_to_rearrange_enabled"), "set_drag_to_rearrange_enabled", "get_drag_to_rearrange_enabled");
 
 	BIND_ENUM_CONSTANT(ALIGN_LEFT);
 	BIND_ENUM_CONSTANT(ALIGN_CENTER);
@@ -694,4 +853,6 @@ TabContainer::TabContainer() {
 	align = ALIGN_CENTER;
 	tabs_visible = true;
 	popup = NULL;
+	drag_to_rearrange_enabled = false;
+	tabs_rearrange_group = -1;
 }
diff --git a/scene/gui/tab_container.h b/scene/gui/tab_container.h
index 4bc6e00145..1afe5f7541 100644
--- a/scene/gui/tab_container.h
+++ b/scene/gui/tab_container.h
@@ -58,6 +58,8 @@ private:
 	Control *_get_tab(int p_idx) const;
 	int _get_top_margin() const;
 	Popup *popup;
+	bool drag_to_rearrange_enabled;
+	int tabs_rearrange_group;
 
 	Vector<Control *> _get_tabs() const;
 	int _get_tab_width(int p_index) const;
@@ -71,6 +73,11 @@ protected:
 	virtual void add_child_notify(Node *p_child);
 	virtual void remove_child_notify(Node *p_child);
 
+	Variant get_drag_data(const Point2 &p_point);
+	bool can_drop_data(const Point2 &p_point, const Variant &p_data) const;
+	void drop_data(const Point2 &p_point, const Variant &p_data);
+	int get_tab_idx_at_point(const Point2 &p_point) const;
+
 	static void _bind_methods();
 
 public:
@@ -104,6 +111,11 @@ public:
 	void set_popup(Node *p_popup);
 	Popup *get_popup() const;
 
+	void set_drag_to_rearrange_enabled(bool p_enabled);
+	bool get_drag_to_rearrange_enabled() const;
+	void set_tabs_rearrange_group(int p_group_id);
+	int get_tabs_rearrange_group() const;
+
 	TabContainer();
 };
 
diff --git a/scene/gui/tabs.cpp b/scene/gui/tabs.cpp
index dee32aef7a..b114264de1 100644
--- a/scene/gui/tabs.cpp
+++ b/scene/gui/tabs.cpp
@@ -31,6 +31,9 @@
 #include "tabs.h"
 
 #include "message_queue.h"
+#include "scene/gui/box_container.h"
+#include "scene/gui/label.h"
+#include "scene/gui/texture_rect.h"
 
 Size2 Tabs::get_minimum_size() const {
 
@@ -624,20 +627,105 @@ void Tabs::remove_tab(int p_idx) {
 
 Variant Tabs::get_drag_data(const Point2 &p_point) {
 
-	return get_tab_idx_at_point(p_point);
+	if (!drag_to_rearrange_enabled)
+		return Variant();
+
+	int tab_over = get_tab_idx_at_point(p_point);
+
+	if (tab_over < 0)
+		return Variant();
+
+	HBoxContainer *drag_preview = memnew(HBoxContainer);
+
+	if (!tabs[tab_over].icon.is_null()) {
+		TextureRect *tf = memnew(TextureRect);
+		tf->set_texture(tabs[tab_over].icon);
+		drag_preview->add_child(tf);
+	}
+	Label *label = memnew(Label(tabs[tab_over].text));
+	drag_preview->add_child(label);
+	if (!tabs[tab_over].right_button.is_null()) {
+		TextureRect *tf = memnew(TextureRect);
+		tf->set_texture(tabs[tab_over].right_button);
+		drag_preview->add_child(tf);
+	}
+	set_drag_preview(drag_preview);
+
+	Dictionary drag_data;
+	drag_data["type"] = "tab_element";
+	drag_data["tab_element"] = tab_over;
+	drag_data["from_path"] = get_path();
+	return drag_data;
 }
 
 bool Tabs::can_drop_data(const Point2 &p_point, const Variant &p_data) const {
 
-	return get_tab_idx_at_point(p_point) > -1;
+	if (!drag_to_rearrange_enabled)
+		return false;
+
+	Dictionary d = p_data;
+	if (!d.has("type"))
+		return false;
+
+	if (String(d["type"]) == "tab_element") {
+
+		NodePath from_path = d["from_path"];
+		NodePath to_path = get_path();
+		if (from_path == to_path) {
+			return true;
+		} else if (get_tabs_rearrange_group() != -1) {
+			// drag and drop between other Tabs
+			Node *from_node = get_node(from_path);
+			Tabs *from_tabs = Object::cast_to<Tabs>(from_node);
+			if (from_tabs && from_tabs->get_tabs_rearrange_group() == get_tabs_rearrange_group()) {
+				return true;
+			}
+		}
+	}
+	return false;
 }
 
 void Tabs::drop_data(const Point2 &p_point, const Variant &p_data) {
 
+	if (!drag_to_rearrange_enabled)
+		return;
+
 	int hover_now = get_tab_idx_at_point(p_point);
 
-	ERR_FAIL_INDEX(hover_now, tabs.size());
-	emit_signal("reposition_active_tab_request", hover_now);
+	Dictionary d = p_data;
+	if (!d.has("type"))
+		return;
+
+	if (String(d["type"]) == "tab_element") {
+
+		int tab_from_id = d["tab_element"];
+		NodePath from_path = d["from_path"];
+		NodePath to_path = get_path();
+		if (from_path == to_path) {
+			if (hover_now < 0)
+				hover_now = get_tab_count() - 1;
+			move_tab(tab_from_id, hover_now);
+			emit_signal("reposition_active_tab_request", hover_now);
+			set_current_tab(hover_now);
+		} else if (get_tabs_rearrange_group() != -1) {
+			// drag and drop between Tabs
+			Node *from_node = get_node(from_path);
+			Tabs *from_tabs = Object::cast_to<Tabs>(from_node);
+			if (from_tabs && from_tabs->get_tabs_rearrange_group() == get_tabs_rearrange_group()) {
+				if (tab_from_id >= from_tabs->get_tab_count())
+					return;
+				Tab moving_tab = from_tabs->tabs[tab_from_id];
+				if (hover_now < 0)
+					hover_now = get_tab_count();
+				tabs.insert(hover_now, moving_tab);
+				from_tabs->remove_tab(tab_from_id);
+				set_current_tab(hover_now);
+				emit_signal("tab_changed", hover_now);
+				_update_cache();
+			}
+		}
+	}
+	update();
 }
 
 int Tabs::get_tab_idx_at_point(const Point2 &p_point) const {
@@ -817,6 +905,21 @@ bool Tabs::get_scrolling_enabled() const {
 	return scrolling_enabled;
 }
 
+void Tabs::set_drag_to_rearrange_enabled(bool p_enabled) {
+	drag_to_rearrange_enabled = p_enabled;
+}
+
+bool Tabs::get_drag_to_rearrange_enabled() const {
+	return drag_to_rearrange_enabled;
+}
+void Tabs::set_tabs_rearrange_group(int p_group_id) {
+	tabs_rearrange_group = p_group_id;
+}
+
+int Tabs::get_tabs_rearrange_group() const {
+	return tabs_rearrange_group;
+}
+
 void Tabs::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("_gui_input"), &Tabs::_gui_input);
@@ -842,6 +945,10 @@ void Tabs::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("get_tab_close_display_policy"), &Tabs::get_tab_close_display_policy);
 	ClassDB::bind_method(D_METHOD("set_scrolling_enabled", "enabled"), &Tabs::set_scrolling_enabled);
 	ClassDB::bind_method(D_METHOD("get_scrolling_enabled"), &Tabs::get_scrolling_enabled);
+	ClassDB::bind_method(D_METHOD("set_drag_to_rearrange_enabled", "enabled"), &Tabs::set_drag_to_rearrange_enabled);
+	ClassDB::bind_method(D_METHOD("get_drag_to_rearrange_enabled"), &Tabs::get_drag_to_rearrange_enabled);
+	ClassDB::bind_method(D_METHOD("set_tabs_rearrange_group", "group_id"), &Tabs::set_tabs_rearrange_group);
+	ClassDB::bind_method(D_METHOD("get_tabs_rearrange_group"), &Tabs::get_tabs_rearrange_group);
 
 	ADD_SIGNAL(MethodInfo("tab_changed", PropertyInfo(Variant::INT, "tab")));
 	ADD_SIGNAL(MethodInfo("right_button_pressed", PropertyInfo(Variant::INT, "tab")));
@@ -854,6 +961,7 @@ void Tabs::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "tab_align", PROPERTY_HINT_ENUM, "Left,Center,Right"), "set_tab_align", "get_tab_align");
 	ADD_PROPERTYNZ(PropertyInfo(Variant::INT, "tab_close_display_policy", PROPERTY_HINT_ENUM, "Show Never,Show Active Only,Show Always"), "set_tab_close_display_policy", "get_tab_close_display_policy");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "scrolling_enabled"), "set_scrolling_enabled", "get_scrolling_enabled");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "drag_to_rearrange_enabled"), "set_drag_to_rearrange_enabled", "get_drag_to_rearrange_enabled");
 
 	BIND_ENUM_CONSTANT(ALIGN_LEFT);
 	BIND_ENUM_CONSTANT(ALIGN_CENTER);
@@ -884,4 +992,6 @@ Tabs::Tabs() {
 	scrolling_enabled = true;
 	buttons_visible = false;
 	hover = -1;
+	drag_to_rearrange_enabled = false;
+	tabs_rearrange_group = -1;
 }
diff --git a/scene/gui/tabs.h b/scene/gui/tabs.h
index 246b3cba67..3b38e7f2cb 100644
--- a/scene/gui/tabs.h
+++ b/scene/gui/tabs.h
@@ -90,6 +90,8 @@ private:
 	int hover; // hovered tab
 	int min_width;
 	bool scrolling_enabled;
+	bool drag_to_rearrange_enabled;
+	int tabs_rearrange_group;
 
 	int get_tab_width(int p_idx) const;
 	void _ensure_no_over_offset();
@@ -143,6 +145,11 @@ public:
 	void set_scrolling_enabled(bool p_enabled);
 	bool get_scrolling_enabled() const;
 
+	void set_drag_to_rearrange_enabled(bool p_enabled);
+	bool get_drag_to_rearrange_enabled() const;
+	void set_tabs_rearrange_group(int p_group_id);
+	int get_tabs_rearrange_group() const;
+
 	void ensure_tab_visible(int p_idx);
 	void set_min_width(int p_width);