From 481fd5ae4c44fa2264d5613f5e80ea1f3ce2bd76 Mon Sep 17 00:00:00 2001
From: viliusle <www.viliusl@gmail.com>
Date: Sat, 3 Apr 2021 23:06:56 +0300
Subject: [PATCH] exit confirmation

---
 src/js/core/base-gui.js          | 14 ++++++++++++++
 src/js/core/base-layers.js       |  2 +-
 src/js/modules/tools/settings.js |  4 ++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/src/js/core/base-gui.js b/src/js/core/base-gui.js
index 0644ebe..f0f51ad 100644
--- a/src/js/core/base-gui.js
+++ b/src/js/core/base-gui.js
@@ -4,6 +4,7 @@
  */
 
 import config from './../config.js';
+import Base_layers_class from './base-layers.js';
 import GUI_tools_class from './gui/gui-tools.js';
 import GUI_preview_class from './gui/gui-preview.js';
 import GUI_colors_class from './gui/gui-colors.js';
@@ -12,6 +13,7 @@ import GUI_information_class from './gui/gui-information.js';
 import GUI_details_class from './gui/gui-details.js';
 import GUI_menu_class from './gui/gui-menu.js';
 import Tools_translate_class from './../modules/tools/translate.js';
+import Tools_settings_class from './../modules/tools/settings.js';
 import Helper_class from './../libs/helpers.js';
 import alertify from './../../../node_modules/alertifyjs/build/alertify.min.js';
 
@@ -30,6 +32,7 @@ class Base_gui_class {
 		instance = this;
 
 		this.Helper = new Helper_class();
+		this.Base_layers = new Base_layers_class();
 
 		//last used menu id
 		this.last_menu = '';
@@ -62,6 +65,7 @@ class Base_gui_class {
 		this.GUI_details = new GUI_details_class(this);
 		this.GUI_menu = new GUI_menu_class();
 		this.Tools_translate = new Tools_translate_class();
+		this.Tools_settings = new Tools_settings_class();
 		this.modules = {};
 	}
 
@@ -205,6 +209,16 @@ class Base_gui_class {
 			config.need_render = true;
 		}, false);
 		this.check_canvas_offset();
+
+		//confirmation on exit
+		var exit_confirm = this.Tools_settings.get_setting('exit_confirm');
+		window.addEventListener('beforeunload', function (e) {
+			if(exit_confirm && (config.layers.length > 1 || _this.Base_layers.is_layer_empty(config.layer.id) == false)){
+				e.preventDefault();
+				e.returnValue = '';
+			}
+			return undefined;
+		});
 	}
 
 	check_canvas_offset() {
diff --git a/src/js/core/base-layers.js b/src/js/core/base-layers.js
index 0869ba8..4234be8 100644
--- a/src/js/core/base-layers.js
+++ b/src/js/core/base-layers.js
@@ -501,7 +501,7 @@ class Base_layers_class {
 	is_layer_empty(id) {
 		var link = this.get_layer(id);
 
-		if (link.width == 0 && link.height == 0 && link.data == null) {
+		if ((link.width == 0 || link.width === null) && (link.height == 0 || link.height === null) && link.data == null) {
 			return true;
 		}
 
diff --git a/src/js/modules/tools/settings.js b/src/js/modules/tools/settings.js
index 0c37933..7bf3a65 100644
--- a/src/js/modules/tools/settings.js
+++ b/src/js/modules/tools/settings.js
@@ -21,6 +21,7 @@ class Tools_settings_class {
 		var snap = this.get_setting('snap');
 		var guides = this.get_setting('guides');
 		var safe_search = this.get_setting('safe_search');
+		var exit_confirm = this.get_setting('exit_confirm');
 
 		var settings = {
 			title: 'Settings',
@@ -33,6 +34,7 @@ class Tools_settings_class {
 				{name: "snap", title: "Enable snap:", value: snap},
 				{name: "guides", title: "Enable guides:", value: guides},
 				{name: "safe_search", title: "Safe search:", value: safe_search},
+				{name: "exit_confirm", title: "Exit confirmation:", value: exit_confirm},
 			],
 			on_change: function (params) {
 				this.Base_gui.change_theme(params.theme);
@@ -57,6 +59,7 @@ class Tools_settings_class {
 		this.save_setting('snap', params.snap);
 		this.save_setting('guides', params.guides);
 		this.save_setting('safe_search', params.safe_search);
+		this.save_setting('exit_confirm', params.exit_confirm);
 
 		//update config
 		config.TRANSPARENCY = this.get_setting('transparency');
@@ -102,6 +105,7 @@ class Tools_settings_class {
 			'snap': true,
 			'guides': true,
 			'safe_search': false,
+			'exit_confirm': true,
 		};
 
 		var value = this.Helper.getCookie(key);