Add the About dialog to the project manager

The About button is located in the bottom-right corner of the
project manager.

This allows removing the copyright notice from the window title
(which looked a bit ugly in comparison to other applications).

editor/editor_about.cpp

@@ -38,16 +38,15 @@
 #include "core/version_hash.gen.h"
 
 void EditorAbout::_theme_changed() {
-	Control *base = EditorNode::get_singleton()->get_gui_base();
+	const Ref<Font> font = get_theme_font("source", "EditorFonts");
-	Ref<Font> font = base->get_theme_font("source", "EditorFonts");
+	const int font_size = get_theme_font_size("source_size", "EditorFonts");
-	int font_size = base->get_theme_font_size("source_size", "EditorFonts");
 	_tpl_text->add_theme_font_override("normal_font", font);
 	_tpl_text->add_theme_font_size_override("normal_font_size", font_size);
 	_tpl_text->add_theme_constant_override("line_separation", 6 * EDSCALE);
 	_license_text->add_theme_font_override("normal_font", font);
 	_license_text->add_theme_font_size_override("normal_font_size", font_size);
 	_license_text->add_theme_constant_override("line_separation", 6 * EDSCALE);
-	_logo->set_texture(base->get_theme_icon("Logo", "EditorIcons"));
+	_logo->set_texture(get_theme_icon("Logo", "EditorIcons"));
 }
 
 void EditorAbout::_notification(int p_what) {

editor/editor_about.h

@@ -44,6 +44,10 @@
 
 #include "editor_scale.h"
 
+/**
+ * NOTE: Do not assume the EditorNode singleton to be available in this class' methods.
+ * EditorAbout is also used from the project manager where EditorNode isn't initialized.
+ */
 class EditorAbout : public AcceptDialog {
 	GDCLASS(EditorAbout, AcceptDialog);
 

editor/project_manager.cpp

@@ -1852,6 +1852,9 @@ void ProjectManager::_notification(int p_what) {
 		case NOTIFICATION_WM_CLOSE_REQUEST: {
 			_dim_window();
 		} break;
+		case NOTIFICATION_WM_ABOUT: {
+			_show_about();
+		} break;
 	}
 }
 
@@ -2255,6 +2258,10 @@ void ProjectManager::_erase_missing_projects() {
 	erase_missing_ask->popup_centered();
 }
 
+void ProjectManager::_show_about() {
+	about->popup_centered(Size2(780, 500) * EDSCALE);
+}
+
 void ProjectManager::_language_selected(int p_id) {
 	String lang = language_btn->get_item_metadata(p_id);
 	EditorSettings::get_singleton()->set("interface/editor/editor_language", lang);
@@ -2444,12 +2451,7 @@ ProjectManager::ProjectManager() {
 	}
 
 	// TRANSLATORS: This refers to the application where users manage their Godot projects.
-	if (TS->is_locale_right_to_left(TranslationServer::get_singleton()->get_tool_locale())) {
+	DisplayServer::get_singleton()->window_set_title(VERSION_NAME + String(" - ") + TTR("Project Manager"));
-		// For RTL languages, embed translated part of the title (using control characters) to ensure correct order.
-		DisplayServer::get_singleton()->window_set_title(VERSION_NAME + String(" - ") + String::chr(0x202B) + TTR("Project Manager") + String::chr(0x202C) + String::chr(0x200E) + " - " + String::chr(0xA9) + " 2007-2021 Juan Linietsky, Ariel Manzur & Godot Contributors");
-	} else {
-		DisplayServer::get_singleton()->window_set_title(VERSION_NAME + String(" - ") + TTR("Project Manager") + " - " + String::chr(0xA9) + " 2007-2021 Juan Linietsky, Ariel Manzur & Godot Contributors");
-	}
 
 	FileDialog::set_default_show_hidden_files(EditorSettings::get_singleton()->get("filesystem/file_dialog/show_hidden_files"));
 
@@ -2583,6 +2585,13 @@ ProjectManager::ProjectManager() {
 		erase_missing_btn->set_text(TTR("Remove Missing"));
 		erase_missing_btn->connect("pressed", callable_mp(this, &ProjectManager::_erase_missing_projects));
 		tree_vb->add_child(erase_missing_btn);
+
+		tree_vb->add_spacer();
+
+		about_btn = memnew(Button);
+		about_btn->set_text(TTR("About"));
+		about_btn->connect("pressed", callable_mp(this, &ProjectManager::_show_about));
+		tree_vb->add_child(about_btn);
 	}
 
 	{
@@ -2716,6 +2725,9 @@ ProjectManager::ProjectManager() {
 		open_templates->get_ok_button()->set_text(TTR("Open Asset Library"));
 		open_templates->connect("confirmed", callable_mp(this, &ProjectManager::_open_asset_library));
 		add_child(open_templates);
+
+		about = memnew(EditorAbout);
+		add_child(about);
 	}
 
 	_load_recent_projects();

editor/project_manager.h

@@ -31,6 +31,7 @@
 #ifndef PROJECT_MANAGER_H
 #define PROJECT_MANAGER_H
 
+#include "editor/editor_about.h"
 #include "editor/plugins/asset_library_editor_plugin.h"
 #include "scene/gui/dialogs.h"
 #include "scene/gui/file_dialog.h"
@@ -62,6 +63,7 @@ class ProjectManager : public Control {
 	Button *rename_btn;
 	Button *erase_btn;
 	Button *erase_missing_btn;
+	Button *about_btn;
 
 	EditorAssetLibrary *asset_library;
 
@@ -78,6 +80,7 @@ class ProjectManager : public Control {
 	ConfirmationDialog *multi_scan_ask;
 	ConfirmationDialog *ask_update_settings;
 	ConfirmationDialog *open_templates;
+	EditorAbout *about;
 
 	HBoxContainer *settings_hb;
 
@@ -100,6 +103,7 @@ class ProjectManager : public Control {
 	void _erase_missing_projects();
 	void _erase_project_confirm();
 	void _erase_missing_projects_confirm();
+	void _show_about();
 	void _update_project_buttons();
 	void _language_selected(int p_id);
 	void _restart_confirm();