Add ThemeOwner type for managing theme propagation and lookup

2 files changed, 446 insertions, 0 deletions

diff --git a/scene/theme/theme_owner.cpp b/scene/theme/theme_owner.cpp
new file mode 100644
index 0000000000..1ac1d0f9fe
--- /dev/null
+++ b/scene/theme/theme_owner.cpp
@@ -0,0 +1,373 @@
+/*************************************************************************/
+/*  theme_owner.cpp                                                      */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "theme_owner.h"
+
+#include "scene/gui/control.h"
+#include "scene/main/window.h"
+#include "scene/theme/theme_db.h"
+
+// Theme owner node.
+
+void ThemeOwner::set_owner_node(Node *p_node) {
+	owner_control = nullptr;
+	owner_window = nullptr;
+
+	Control *c = Object::cast_to<Control>(p_node);
+	if (c) {
+		owner_control = c;
+		return;
+	}
+
+	Window *w = Object::cast_to<Window>(p_node);
+	if (w) {
+		owner_window = w;
+		return;
+	}
+}
+
+Node *ThemeOwner::get_owner_node() const {
+	if (owner_control) {
+		return owner_control;
+	} else if (owner_window) {
+		return owner_window;
+	}
+	return nullptr;
+}
+
+bool ThemeOwner::has_owner_node() const {
+	return bool(owner_control || owner_window);
+}
+
+// Theme propagation.
+
+void ThemeOwner::propagate_theme_changed(Node *p_to_node, Node *p_owner_node, bool p_notify, bool p_assign) {
+	Control *c = Object::cast_to<Control>(p_to_node);
+	Window *w = c == nullptr ? Object::cast_to<Window>(p_to_node) : nullptr;
+
+	if (!c && !w) {
+		// Theme inheritance chains are broken by nodes that aren't Control or Window.
+		return;
+	}
+
+	bool assign = p_assign;
+	if (c) {
+		if (c != p_owner_node && c->get_theme().is_valid()) {
+			// Has a theme, so we don't want to change the theme owner,
+			// but we still want to propagate in case this child has theme items
+			// it inherits from the theme this node uses.
+			// See https://github.com/godotengine/godot/issues/62844.
+			assign = false;
+		}
+
+		if (assign) {
+			c->set_theme_owner_node(p_owner_node);
+		}
+
+		if (p_notify) {
+			c->notification(Control::NOTIFICATION_THEME_CHANGED);
+		}
+	} else if (w) {
+		if (w != p_owner_node && w->get_theme().is_valid()) {
+			// Same as above.
+			assign = false;
+		}
+
+		if (assign) {
+			w->set_theme_owner_node(p_owner_node);
+		}
+
+		if (p_notify) {
+			w->notification(Window::NOTIFICATION_THEME_CHANGED);
+		}
+	}
+
+	for (int i = 0; i < p_to_node->get_child_count(); i++) {
+		propagate_theme_changed(p_to_node->get_child(i), p_owner_node, p_notify, assign);
+	}
+}
+
+// Theme lookup.
+
+void ThemeOwner::get_theme_type_dependencies(const Node *p_for_node, const StringName &p_theme_type, List<StringName> *r_list) const {
+	const Control *for_c = Object::cast_to<Control>(p_for_node);
+	const Window *for_w = Object::cast_to<Window>(p_for_node);
+	ERR_FAIL_COND_MSG(!for_c && !for_w, "Only Control and Window nodes and derivatives can be polled for theming.");
+
+	Ref<Theme> default_theme = ThemeDB::get_singleton()->get_default_theme();
+	Ref<Theme> project_theme = ThemeDB::get_singleton()->get_project_theme();
+
+	StringName type_variation;
+	if (for_c) {
+		type_variation = for_c->get_theme_type_variation();
+	} else if (for_w) {
+		type_variation = for_w->get_theme_type_variation();
+	}
+
+	if (p_theme_type == StringName() || p_theme_type == p_for_node->get_class_name() || p_theme_type == type_variation) {
+		if (project_theme.is_valid() && project_theme->get_type_variation_base(type_variation) != StringName()) {
+			project_theme->get_type_dependencies(p_for_node->get_class_name(), type_variation, r_list);
+		} else {
+			default_theme->get_type_dependencies(p_for_node->get_class_name(), type_variation, r_list);
+		}
+	} else {
+		default_theme->get_type_dependencies(p_theme_type, StringName(), r_list);
+	}
+}
+
+Node *ThemeOwner::_get_next_owner_node(Node *p_from_node) const {
+	Node *parent = p_from_node->get_parent();
+
+	Control *parent_c = Object::cast_to<Control>(parent);
+	if (parent_c) {
+		return parent_c->get_theme_owner_node();
+	} else {
+		Window *parent_w = Object::cast_to<Window>(parent);
+		if (parent_w) {
+			return parent_w->get_theme_owner_node();
+		}
+	}
+
+	return nullptr;
+}
+
+Variant ThemeOwner::get_theme_item_in_types(Theme::DataType p_data_type, const StringName &p_name, List<StringName> p_theme_types) {
+	ERR_FAIL_COND_V_MSG(p_theme_types.size() == 0, Variant(), "At least one theme type must be specified.");
+
+	// First, look through each control or window node in the branch, until no valid parent can be found.
+	// Only nodes with a theme resource attached are considered.
+	Node *owner_node = get_owner_node();
+
+	while (owner_node) {
+		// For each theme resource check the theme types provided and see if p_name exists with any of them.
+		for (const StringName &E : p_theme_types) {
+			Ref<Theme> owner_theme;
+
+			Control *owner_c = Object::cast_to<Control>(owner_node);
+			if (owner_c) {
+				owner_theme = owner_c->get_theme();
+			}
+			Window *owner_w = Object::cast_to<Window>(owner_node);
+			if (owner_w) {
+				owner_theme = owner_w->get_theme();
+			}
+
+			if (owner_theme.is_valid() && owner_theme->has_theme_item(p_data_type, p_name, E)) {
+				return owner_theme->get_theme_item(p_data_type, p_name, E);
+			}
+		}
+
+		owner_node = _get_next_owner_node(owner_node);
+	}
+
+	// Secondly, check the project-defined Theme resource.
+	if (ThemeDB::get_singleton()->get_project_theme().is_valid()) {
+		for (const StringName &E : p_theme_types) {
+			if (ThemeDB::get_singleton()->get_project_theme()->has_theme_item(p_data_type, p_name, E)) {
+				return ThemeDB::get_singleton()->get_project_theme()->get_theme_item(p_data_type, p_name, E);
+			}
+		}
+	}
+
+	// Lastly, fall back on the items defined in the default Theme, if they exist.
+	for (const StringName &E : p_theme_types) {
+		if (ThemeDB::get_singleton()->get_default_theme()->has_theme_item(p_data_type, p_name, E)) {
+			return ThemeDB::get_singleton()->get_default_theme()->get_theme_item(p_data_type, p_name, E);
+		}
+	}
+
+	// If they don't exist, use any type to return the default/empty value.
+	return ThemeDB::get_singleton()->get_default_theme()->get_theme_item(p_data_type, p_name, p_theme_types[0]);
+}
+
+bool ThemeOwner::has_theme_item_in_types(Theme::DataType p_data_type, const StringName &p_name, List<StringName> p_theme_types) {
+	ERR_FAIL_COND_V_MSG(p_theme_types.size() == 0, false, "At least one theme type must be specified.");
+
+	// First, look through each control or window node in the branch, until no valid parent can be found.
+	// Only nodes with a theme resource attached are considered.
+	Node *owner_node = get_owner_node();
+
+	while (owner_node) {
+		// For each theme resource check the theme types provided and see if p_name exists with any of them.
+		for (const StringName &E : p_theme_types) {
+			Ref<Theme> owner_theme;
+
+			Control *owner_c = Object::cast_to<Control>(owner_node);
+			if (owner_c) {
+				owner_theme = owner_c->get_theme();
+			}
+			Window *owner_w = Object::cast_to<Window>(owner_node);
+			if (owner_w) {
+				owner_theme = owner_w->get_theme();
+			}
+
+			if (owner_theme.is_valid() && owner_theme->has_theme_item(p_data_type, p_name, E)) {
+				return true;
+			}
+		}
+
+		owner_node = _get_next_owner_node(owner_node);
+	}
+
+	// Secondly, check the project-defined Theme resource.
+	if (ThemeDB::get_singleton()->get_project_theme().is_valid()) {
+		for (const StringName &E : p_theme_types) {
+			if (ThemeDB::get_singleton()->get_project_theme()->has_theme_item(p_data_type, p_name, E)) {
+				return true;
+			}
+		}
+	}
+
+	// Lastly, fall back on the items defined in the default Theme, if they exist.
+	for (const StringName &E : p_theme_types) {
+		if (ThemeDB::get_singleton()->get_default_theme()->has_theme_item(p_data_type, p_name, E)) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
+float ThemeOwner::get_theme_default_base_scale() {
+	// First, look through each control or window node in the branch, until no valid parent can be found.
+	// Only nodes with a theme resource attached are considered.
+	// For each theme resource see if their assigned theme has the default value defined and valid.
+	Node *owner_node = get_owner_node();
+
+	while (owner_node) {
+		Ref<Theme> owner_theme;
+
+		Control *owner_c = Object::cast_to<Control>(owner_node);
+		if (owner_c) {
+			owner_theme = owner_c->get_theme();
+		}
+		Window *owner_w = Object::cast_to<Window>(owner_node);
+		if (owner_w) {
+			owner_theme = owner_w->get_theme();
+		}
+
+		if (owner_theme.is_valid() && owner_theme->has_default_base_scale()) {
+			return owner_theme->get_default_base_scale();
+		}
+
+		owner_node = _get_next_owner_node(owner_node);
+	}
+
+	// Secondly, check the project-defined Theme resource.
+	if (ThemeDB::get_singleton()->get_project_theme().is_valid()) {
+		if (ThemeDB::get_singleton()->get_project_theme()->has_default_base_scale()) {
+			return ThemeDB::get_singleton()->get_project_theme()->get_default_base_scale();
+		}
+	}
+
+	// Lastly, fall back on the default Theme.
+	if (ThemeDB::get_singleton()->get_default_theme()->has_default_base_scale()) {
+		return ThemeDB::get_singleton()->get_default_theme()->get_default_base_scale();
+	}
+	return ThemeDB::get_singleton()->get_fallback_base_scale();
+}
+
+Ref<Font> ThemeOwner::get_theme_default_font() {
+	// First, look through each control or window node in the branch, until no valid parent can be found.
+	// Only nodes with a theme resource attached are considered.
+	// For each theme resource see if their assigned theme has the default value defined and valid.
+	Node *owner_node = get_owner_node();
+
+	while (owner_node) {
+		Ref<Theme> owner_theme;
+
+		Control *owner_c = Object::cast_to<Control>(owner_node);
+		if (owner_c) {
+			owner_theme = owner_c->get_theme();
+		}
+		Window *owner_w = Object::cast_to<Window>(owner_node);
+		if (owner_w) {
+			owner_theme = owner_w->get_theme();
+		}
+
+		if (owner_theme.is_valid() && owner_theme->has_default_font()) {
+			return owner_theme->get_default_font();
+		}
+
+		owner_node = _get_next_owner_node(owner_node);
+	}
+
+	// Secondly, check the project-defined Theme resource.
+	if (ThemeDB::get_singleton()->get_project_theme().is_valid()) {
+		if (ThemeDB::get_singleton()->get_project_theme()->has_default_font()) {
+			return ThemeDB::get_singleton()->get_project_theme()->get_default_font();
+		}
+	}
+
+	// Lastly, fall back on the default Theme.
+	if (ThemeDB::get_singleton()->get_default_theme()->has_default_font()) {
+		return ThemeDB::get_singleton()->get_default_theme()->get_default_font();
+	}
+	return ThemeDB::get_singleton()->get_fallback_font();
+}
+
+int ThemeOwner::get_theme_default_font_size() {
+	// First, look through each control or window node in the branch, until no valid parent can be found.
+	// Only nodes with a theme resource attached are considered.
+	// For each theme resource see if their assigned theme has the default value defined and valid.
+	Node *owner_node = get_owner_node();
+
+	while (owner_node) {
+		Ref<Theme> owner_theme;
+
+		Control *owner_c = Object::cast_to<Control>(owner_node);
+		if (owner_c) {
+			owner_theme = owner_c->get_theme();
+		}
+		Window *owner_w = Object::cast_to<Window>(owner_node);
+		if (owner_w) {
+			owner_theme = owner_w->get_theme();
+		}
+
+		if (owner_theme.is_valid() && owner_theme->has_default_font_size()) {
+			return owner_theme->get_default_font_size();
+		}
+
+		owner_node = _get_next_owner_node(owner_node);
+	}
+
+	// Secondly, check the project-defined Theme resource.
+	if (ThemeDB::get_singleton()->get_project_theme().is_valid()) {
+		if (ThemeDB::get_singleton()->get_project_theme()->has_default_font_size()) {
+			return ThemeDB::get_singleton()->get_project_theme()->get_default_font_size();
+		}
+	}
+
+	// Lastly, fall back on the default Theme.
+	if (ThemeDB::get_singleton()->get_default_theme()->has_default_font_size()) {
+		return ThemeDB::get_singleton()->get_default_theme()->get_default_font_size();
+	}
+	return ThemeDB::get_singleton()->get_fallback_font_size();
+}
diff --git a/scene/theme/theme_owner.h b/scene/theme/theme_owner.h
new file mode 100644
index 0000000000..38344c3d9e
--- /dev/null
+++ b/scene/theme/theme_owner.h
@@ -0,0 +1,73 @@
+/*************************************************************************/
+/*  theme_owner.h                                                        */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef THEME_OWNER_H
+#define THEME_OWNER_H
+
+#include "core/object/object.h"
+#include "scene/resources/theme.h"
+
+class Control;
+class Node;
+class Window;
+
+class ThemeOwner : public Object {
+	Control *owner_control = nullptr;
+	Window *owner_window = nullptr;
+
+	Node *_get_next_owner_node(Node *p_from_node) const;
+
+public:
+	// Theme owner node.
+
+	void set_owner_node(Node *p_node);
+	Node *get_owner_node() const;
+	bool has_owner_node() const;
+
+	// Theme propagation.
+
+	void propagate_theme_changed(Node *p_to_node, Node *p_owner_node, bool p_notify, bool p_assign);
+
+	// Theme lookup.
+
+	void get_theme_type_dependencies(const Node *p_for_node, const StringName &p_theme_type, List<StringName> *r_list) const;
+
+	Variant get_theme_item_in_types(Theme::DataType p_data_type, const StringName &p_name, List<StringName> p_theme_types);
+	bool has_theme_item_in_types(Theme::DataType p_data_type, const StringName &p_name, List<StringName> p_theme_types);
+
+	float get_theme_default_base_scale();
+	Ref<Font> get_theme_default_font();
+	int get_theme_default_font_size();
+
+	ThemeOwner() {}
+	~ThemeOwner() {}
+};
+
+#endif // THEME_OWNER_H