From 24cc33e7046fc4b90bf8e1b2fd2546c699fc6eee Mon Sep 17 00:00:00 2001
From: rubenwardy <rw@rubenwardy.com>
Date: Sun, 24 Mar 2024 17:19:23 +0000
Subject: [PATCH] Add button_url[] and hypertext element to allow mods to open
 web pages (#13825)

Fixes #12500
---
 builtin/mainmenu/tab_about.lua               |   6 +-
 doc/lua_api.md                               |  19 ++
 games/devtest/mods/testformspec/formspec.lua |   8 +-
 src/client/game.cpp                          |   7 +
 src/gui/CMakeLists.txt                       |   1 +
 src/gui/guiFormSpecMenu.cpp                  |  23 ++-
 src/gui/guiFormSpecMenu.h                    |   1 +
 src/gui/guiHyperText.cpp                     |  14 ++
 src/gui/guiOpenURL.cpp                       | 196 +++++++++++++++++++
 src/gui/guiOpenURL.h                         |  50 +++++
 src/gui/mainmenumanager.h                    |  19 +-
 src/unittest/test_utilities.cpp              |  19 ++
 src/util/CMakeLists.txt                      |   1 +
 src/util/colorize.cpp                        | 113 +++++++++++
 src/util/colorize.h                          |  34 ++++
 src/util/string.cpp                          |  34 ++++
 src/util/string.h                            |  22 +--
 17 files changed, 530 insertions(+), 37 deletions(-)
 create mode 100644 src/gui/guiOpenURL.cpp
 create mode 100644 src/gui/guiOpenURL.h
 create mode 100644 src/util/colorize.cpp
 create mode 100644 src/util/colorize.h

diff --git a/builtin/mainmenu/tab_about.lua b/builtin/mainmenu/tab_about.lua
index 8c5573399..1805acc81 100644
--- a/builtin/mainmenu/tab_about.lua
+++ b/builtin/mainmenu/tab_about.lua
@@ -158,7 +158,7 @@ return {
 			"style[label_button;border=false]" ..
 			"button[0.1,3.4;5.3,0.5;label_button;" ..
 			core.formspec_escape(version.project .. " " .. version.string) .. "]" ..
-			"button[1.5,4.1;2.5,0.8;homepage;minetest.net]" ..
+			"button_url[1.5,4.1;2.5,0.8;homepage;minetest.net;https://www.minetest.net/]" ..
 			"hypertext[5.5,0.25;9.75,6.6;credits;" .. minetest.formspec_escape(hypertext) .. "]"
 
 		-- Render information
@@ -188,10 +188,6 @@ return {
 	end,
 
 	cbf_button_handler = function(this, fields, name, tabdata)
-		if fields.homepage then
-			core.open_url("https://www.minetest.net")
-		end
-
 		if fields.share_debug then
 			local path = core.get_user_path() .. DIR_DELIM .. "debug.txt"
 			core.share_file(path)
diff --git a/doc/lua_api.md b/doc/lua_api.md
index b0bcdf34e..3a2e1f47d 100644
--- a/doc/lua_api.md
+++ b/doc/lua_api.md
@@ -3017,6 +3017,16 @@ Elements
   centered on `H`. With the new coordinate system, `H` will modify the height.
 * `label` is the text on the button
 
+### `button_url[<X>,<Y>;<W>,<H>;<name>;<label>;<url>]`
+
+* Clickable button. When clicked, fields will be sent and the user will be given the
+  option to open the URL in a browser.
+* With the old coordinate system, buttons are a set height, but will be vertically
+  centered on `H`. With the new coordinate system, `H` will modify the height.
+* To make this into an `image_button`, you can use formspec styling.
+* `label` is the text on the button.
+* `url` must be a valid web URL, starting with `http://` or `https://`.
+
 ### `image_button[<X>,<Y>;<W>,<H>;<texture name>;<name>;<label>]`
 
 * `texture name` is the filename of an image
@@ -3043,6 +3053,11 @@ Elements
 * When clicked, fields will be sent and the form will quit.
 * Same as `button` in all other respects.
 
+### `button_url_exit[<X>,<Y>;<W>,<H>;<name>;<label>;<url>]`
+
+* When clicked, fields will be sent and the form will quit.
+* Same as `button_url` in all other respects.
+
 ### `image_button_exit[<X>,<Y>;<W>,<H>;<texture name>;<name>;<label>]`
 
 * When clicked, fields will be sent and the form will quit.
@@ -3538,11 +3553,13 @@ Changes the style of the text.
 Sets global style.
 
 Global only styles:
+
 * `background`: Text background, a `colorspec` or `none`.
 * `margin`: Page margins in pixel.
 * `valign`: Text vertical alignment (`top`, `middle`, `bottom`).
 
 Inheriting styles (affects child elements):
+
 * `color`: Default text color. Given color is a `colorspec`.
 * `hovercolor`: Color of <action> tags when mouse is over.
 * `size`: Default text size.
@@ -3556,6 +3573,7 @@ tags appear.
 `<tag name=... color=... hovercolor=... font=... size=...>`
 
 Defines or redefines tag style. This can be used to define new tags.
+
 * `name`: Name of the tag to define or change.
 * `color`: Text color. Given color is a `colorspec`.
 * `hovercolor`: Text color when element hovered (only for `action` tags). Given color is a `colorspec`.
@@ -3588,6 +3606,7 @@ Other tags can be added using `<tag ...>` tag.
 Make that text a clickable text triggering an action.
 
 * `name`: Name of the action (mandatory).
+* `url`: URL to open when the action is triggered (optional).
 
 When clicked, the formspec is send to the server. The value of the text field
 sent to `on_player_receive_fields` will be "action:" concatenated to the action
diff --git a/games/devtest/mods/testformspec/formspec.lua b/games/devtest/mods/testformspec/formspec.lua
index 48c8763de..6e1dd4946 100644
--- a/games/devtest/mods/testformspec/formspec.lua
+++ b/games/devtest/mods/testformspec/formspec.lua
@@ -1,12 +1,15 @@
 local color = minetest.colorize
 
+-- \208\176 is a cyrillic small a
+local unsafe_url = minetest.formspec_escape("https://u:p@wikipedi\208\176.org:1233/heIIoll?a=b#c")
+
 local clip_fs = [[
 	style_type[label,button,image_button,item_image_button,
 			tabheader,scrollbar,table,animated_image
 			,field,textarea,checkbox,dropdown;noclip=%c]
 
 	label[0,0;A clipping test]
-	button[0,1;3,0.8;clip_button;A clipping test]
+	button_url[0,1;3,0.8;clip_button;A clipping test;]] .. unsafe_url .. [[]
 	image_button[0,2;3,0.8;testformspec_button_image.png;clip_image_button;A clipping test]
 	item_image_button[0,3;3,0.8;testformspec:item;clip_item_image_button;A clipping test]
 	tabheader[0,4.7;3,0.63;clip_tabheader;Clip,Test,Text,Tabs;1;false;false]
@@ -92,6 +95,7 @@ This is a normal text.
 <t_green>color=green</t_green>
 Action: <action name=color><t_green>color=green</t_green></action>
 Action: <action name=hovercolor><t_hover>hovercolor=yellow</t_hover></action>
+Action URL: <action name=open url=https://example.com/?a=b#c>open URL</action>
 <t_size>size=24</t_size>
 <t_mono>font=mono</t_mono>
 <t_multi>color=green font=mono size=24</t_multi>
@@ -145,7 +149,7 @@ local hypertext_fs = "hypertext[0,0;11,9;hypertext;"..minetest.formspec_escape(h
 local style_fs = [[
 	style[one_btn1;bgcolor=red;textcolor=yellow;bgcolor_hovered=orange;
 		bgcolor_pressed=purple]
-	button[0,0;2.5,0.8;one_btn1;Button]
+	button_url_exit[0,0;2.5,0.8;one_btn1;Button;]] .. unsafe_url .. [[]
 
 	style[one_btn2;border=false;textcolor=cyan] ]]..
 	"button[0,1.05;2.5,0.8;one_btn2;Text " .. color("#FF0", "Yellow") .. [[]
diff --git a/src/client/game.cpp b/src/client/game.cpp
index a140b730c..84b2815c8 100644
--- a/src/client/game.cpp
+++ b/src/client/game.cpp
@@ -50,6 +50,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "gui/guiFormSpecMenu.h"
 #include "gui/guiKeyChangeMenu.h"
 #include "gui/guiPasswordChange.h"
+#include "gui/guiOpenURL.h"
 #include "gui/guiVolumeChange.h"
 #include "gui/mainmenumanager.h"
 #include "gui/profilergraph.h"
@@ -1815,6 +1816,12 @@ inline bool Game::handleCallbacks()
 		g_gamecallback->keyconfig_requested = false;
 	}
 
+	if (!g_gamecallback->show_open_url_dialog.empty()) {
+		(new GUIOpenURLMenu(guienv, guiroot, -1,
+				 &g_menumgr, texture_src, g_gamecallback->show_open_url_dialog))->drop();
+		g_gamecallback->show_open_url_dialog.clear();
+	}
+
 	if (g_gamecallback->keyconfig_changed) {
 		input->keycache.populate(); // update the cache with new settings
 		g_gamecallback->keyconfig_changed = false;
diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
index 87575f320..66d6a9ee8 100644
--- a/src/gui/CMakeLists.txt
+++ b/src/gui/CMakeLists.txt
@@ -13,6 +13,7 @@ set(gui_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/guiInventoryList.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/guiItemImage.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/guiKeyChangeMenu.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/guiOpenURL.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/guiPasswordChange.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/guiPathSelectMenu.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/guiScene.cpp
diff --git a/src/gui/guiFormSpecMenu.cpp b/src/gui/guiFormSpecMenu.cpp
index 0c616967c..8b66aa4ed 100644
--- a/src/gui/guiFormSpecMenu.cpp
+++ b/src/gui/guiFormSpecMenu.cpp
@@ -976,14 +976,18 @@ void GUIFormSpecMenu::parseItemImage(parserData* data, const std::string &elemen
 void GUIFormSpecMenu::parseButton(parserData* data, const std::string &element,
 		const std::string &type)
 {
+	int expected_parts = (type == "button_url" || type == "button_url_exit") ? 5 : 4;
 	std::vector<std::string> parts;
-	if (!precheckElement("button", element, 4, 4, parts))
+	if (!precheckElement("button", element, expected_parts, expected_parts, parts))
 		return;
 
 	std::vector<std::string> v_pos = split(parts[0],',');
 	std::vector<std::string> v_geom = split(parts[1],',');
 	std::string name = parts[2];
 	std::string label = parts[3];
+	std::string url;
+	if (type == "button_url" || type == "button_url_exit")
+		url = parts[4];
 
 	MY_CHECKPOS("button",0);
 	MY_CHECKGEOM("button",1);
@@ -1018,8 +1022,10 @@ void GUIFormSpecMenu::parseButton(parserData* data, const std::string &element,
 		258 + m_fields.size()
 	);
 	spec.ftype = f_Button;
-	if(type == "button_exit")
+	if (type == "button_exit" || type == "button_url_exit")
 		spec.is_exit = true;
+	if (type == "button_url" || type == "button_url_exit")
+		spec.url = url;
 
 	GUIButton *e = GUIButton::addButton(Environment, rect, m_tsrc,
 			data->current_parent, spec.fid, spec.flabel.c_str());
@@ -2897,7 +2903,7 @@ void GUIFormSpecMenu::parseElement(parserData* data, const std::string &element)
 		return;
 	}
 
-	if (type == "button" || type == "button_exit") {
+	if (type == "button" || type == "button_exit" || type == "button_url" || type == "button_url_exit") {
 		parseButton(data, description, type);
 		return;
 	}
@@ -4968,6 +4974,17 @@ bool GUIFormSpecMenu::OnEvent(const SEvent& event)
 						m_sound_manager->playSound(0, SoundSpec(s.sound, 1.0f));
 
 					s.send = true;
+
+					if (!s.url.empty()) {
+						if (m_client) {
+							// in game
+							g_gamecallback->showOpenURLDialog(s.url);
+						} else {
+							// main menu
+							porting::open_url(s.url);
+						}
+					}
+
 					if (s.is_exit) {
 						if (m_allowclose) {
 							acceptInput(quit_mode_accept);
diff --git a/src/gui/guiFormSpecMenu.h b/src/gui/guiFormSpecMenu.h
index 9f88e5df5..616971bc6 100644
--- a/src/gui/guiFormSpecMenu.h
+++ b/src/gui/guiFormSpecMenu.h
@@ -137,6 +137,7 @@ class GUIFormSpecMenu : public GUIModalMenu
 		std::string fname;
 		std::wstring flabel;
 		std::wstring fdefault;
+		std::string url;
 		s32 fid;
 		bool send;
 		FormspecFieldType ftype;
diff --git a/src/gui/guiHyperText.cpp b/src/gui/guiHyperText.cpp
index 0929fc99f..2dbdf3b99 100644
--- a/src/gui/guiHyperText.cpp
+++ b/src/gui/guiHyperText.cpp
@@ -27,6 +27,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "inventory.h"
 #include "util/string.h"
 #include "irrlicht_changes/CGUITTFont.h"
+#include "mainmenumanager.h"
+#include "porting.h"
 
 using namespace irr::gui;
 
@@ -1106,6 +1108,18 @@ bool GUIHyperText::OnEvent(const SEvent &event)
 							newEvent.GUIEvent.EventType = EGET_BUTTON_CLICKED;
 							Parent->OnEvent(newEvent);
 						}
+
+						auto url_it = tag->attrs.find("url");
+						if (url_it != tag->attrs.end()) {
+							if (g_gamecallback) {
+								// in game
+								g_gamecallback->showOpenURLDialog(url_it->second);
+							} else {
+								// main menu
+								porting::open_url(url_it->second);
+							}
+						}
+
 						break;
 					}
 				}
diff --git a/src/gui/guiOpenURL.cpp b/src/gui/guiOpenURL.cpp
new file mode 100644
index 000000000..547d52c17
--- /dev/null
+++ b/src/gui/guiOpenURL.cpp
@@ -0,0 +1,196 @@
+/*
+Part of Minetest
+Copyright (C) 2023-24 rubenwardy
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "guiOpenURL.h"
+#include "guiButton.h"
+#include "guiEditBoxWithScrollbar.h"
+#include <IGUIEditBox.h>
+#include <IGUIFont.h>
+#include "client/renderingengine.h"
+#include "porting.h"
+#include "gettext.h"
+#include "util/colorize.h"
+
+namespace {
+	constexpr int ID_url = 256;
+	constexpr int ID_open = 259;
+	constexpr int ID_cancel = 261;
+}
+
+GUIOpenURLMenu::GUIOpenURLMenu(gui::IGUIEnvironment* env,
+		gui::IGUIElement* parent, s32 id,
+		IMenuManager *menumgr,
+		ISimpleTextureSource *tsrc, const std::string &url
+):
+	GUIModalMenu(env, parent, id, menumgr),
+	m_tsrc(tsrc),
+	url(url)
+{
+}
+
+
+void GUIOpenURLMenu::regenerateGui(v2u32 screensize)
+{
+	/*
+		Remove stuff
+	*/
+	removeAllChildren();
+
+	/*
+		Calculate new sizes and positions
+	*/
+	const float s = m_gui_scale;
+	DesiredRect = core::rect<s32>(
+		screensize.X / 2 - 580 * s / 2,
+		screensize.Y / 2 - 250 * s / 2,
+		screensize.X / 2 + 580 * s / 2,
+		screensize.Y / 2 + 250 * s / 2
+	);
+	recalculateAbsolutePosition(false);
+
+	v2s32 size = DesiredRect.getSize();
+	v2s32 topleft_client(40 * s, 0);
+
+	/*
+		Get URL text
+	*/
+	bool ok = true;
+	std::string text;
+#ifdef USE_CURL
+	try {
+		text = colorize_url(url);
+	} catch (const std::exception &e) {
+		text = std::string(e.what()) + " (url = " + url + ")";
+		ok = false;
+	}
+#else
+	text = url;
+#endif
+
+	/*
+		Add stuff
+	*/
+	s32 ypos = 40 * s;
+
+	{
+		core::rect<s32> rect(0, 0, 500 * s, 20 * s);
+		rect += topleft_client + v2s32(20 * s, ypos);
+
+		std::wstring title = ok
+				? wstrgettext("Open URL?")
+				: wstrgettext("Unable to open URL");
+		gui::StaticText::add(Environment, title, rect,
+				false, true, this, -1);
+	}
+
+	ypos += 50 * s;
+
+	{
+		core::rect<s32> rect(0, 0, 440 * s, 60 * s);
+
+		auto font = g_fontengine->getFont(FONT_SIZE_UNSPECIFIED,
+				ok ? FM_Mono : FM_Standard);
+		int scrollbar_width = Environment->getSkin()->getSize(gui::EGDS_SCROLLBAR_SIZE);
+		int max_cols = (rect.getWidth() - scrollbar_width - 10) / font->getDimension(L"x").Width;
+
+		text = wrap_rows(text, max_cols, true);
+
+		rect += topleft_client + v2s32(20 * s, ypos);
+		IGUIEditBox *e = new GUIEditBoxWithScrollBar(utf8_to_wide(text).c_str(), true, Environment,
+				this, ID_url, rect, m_tsrc, false, true);
+		e->setMultiLine(true);
+		e->setWordWrap(true);
+		e->setTextAlignment(gui::EGUIA_UPPERLEFT, gui::EGUIA_UPPERLEFT);
+		e->setDrawBorder(true);
+		e->setDrawBackground(true);
+		e->setOverrideFont(font);
+		e->drop();
+	}
+
+	ypos += 80 * s;
+	if (ok) {
+		core::rect<s32> rect(0, 0, 100 * s, 40 * s);
+		rect = rect + v2s32(size.X / 2 - 150 * s, ypos);
+		GUIButton::addButton(Environment, rect, m_tsrc, this, ID_open,
+				wstrgettext("Open").c_str());
+	}
+	{
+		core::rect<s32> rect(0, 0, 100 * s, 40 * s);
+		rect = rect + v2s32(size.X / 2 + 50 * s, ypos);
+		GUIButton::addButton(Environment, rect, m_tsrc, this, ID_cancel,
+				wstrgettext("Cancel").c_str());
+	}
+}
+
+void GUIOpenURLMenu::drawMenu()
+{
+	gui::IGUISkin *skin = Environment->getSkin();
+	if (!skin)
+		return;
+	video::IVideoDriver *driver = Environment->getVideoDriver();
+
+	video::SColor bgcolor(140, 0, 0, 0);
+	driver->draw2DRectangle(bgcolor, AbsoluteRect, &AbsoluteClippingRect);
+
+	gui::IGUIElement::draw();
+#ifdef __ANDROID__
+	getAndroidUIInput();
+#endif
+}
+
+bool GUIOpenURLMenu::OnEvent(const SEvent &event)
+{
+	if (event.EventType == EET_KEY_INPUT_EVENT) {
+		if ((event.KeyInput.Key == KEY_ESCAPE ||
+				event.KeyInput.Key == KEY_CANCEL) &&
+				event.KeyInput.PressedDown) {
+			quitMenu();
+			return true;
+		}
+		if (event.KeyInput.Key == KEY_RETURN && event.KeyInput.PressedDown) {
+			porting::open_url(url);
+			quitMenu();
+			return true;
+		}
+	}
+
+	if (event.EventType == EET_GUI_EVENT) {
+		if (event.GUIEvent.EventType == gui::EGET_ELEMENT_FOCUS_LOST &&
+				isVisible()) {
+			if (!canTakeFocus(event.GUIEvent.Element)) {
+				infostream << "GUIOpenURLMenu: Not allowing focus change."
+					<< std::endl;
+				// Returning true disables focus change
+				return true;
+			}
+		}
+
+		if (event.GUIEvent.EventType == gui::EGET_BUTTON_CLICKED) {
+			switch (event.GUIEvent.Caller->getID()) {
+			case ID_open:
+				porting::open_url(url);
+				quitMenu();
+				return true;
+			case ID_cancel:
+				quitMenu();
+				return true;
+			}
+		}
+	}
+
+	return Parent != nullptr && Parent->OnEvent(event);
+}
diff --git a/src/gui/guiOpenURL.h b/src/gui/guiOpenURL.h
new file mode 100644
index 000000000..8f873c2fa
--- /dev/null
+++ b/src/gui/guiOpenURL.h
@@ -0,0 +1,50 @@
+/*
+Part of Minetest
+Copyright (C) 2023 rubenwardy
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#pragma once
+
+#include "irrlichttypes_extrabloated.h"
+#include "modalMenu.h"
+#include <string>
+
+class Client;
+class ISimpleTextureSource;
+
+class GUIOpenURLMenu : public GUIModalMenu
+{
+public:
+	GUIOpenURLMenu(gui::IGUIEnvironment *env, gui::IGUIElement *parent, s32 id,
+			IMenuManager *menumgr,
+			ISimpleTextureSource *tsrc, const std::string &url);
+
+	/*
+		Remove and re-add (or reposition) stuff
+	*/
+	void regenerateGui(v2u32 screensize);
+
+	void drawMenu();
+
+	bool OnEvent(const SEvent &event);
+
+protected:
+	std::wstring getLabelByID(s32 id) { return L""; }
+	std::string getNameByID(s32 id) { return ""; }
+
+private:
+	ISimpleTextureSource *m_tsrc;
+	std::string url;
+};
diff --git a/src/gui/mainmenumanager.h b/src/gui/mainmenumanager.h
index 4ba420a75..9ef1457cf 100644
--- a/src/gui/mainmenumanager.h
+++ b/src/gui/mainmenumanager.h
@@ -34,7 +34,7 @@ public:
 	virtual void disconnect() = 0;
 	virtual void changePassword() = 0;
 	virtual void changeVolume() = 0;
-
+	virtual void showOpenURLDialog(const std::string &url) = 0;
 	virtual void signalKeyConfigChange() = 0;
 };
 
@@ -108,44 +108,47 @@ public:
 	MainGameCallback() = default;
 	virtual ~MainGameCallback() = default;
 
-	virtual void exitToOS()
+	void exitToOS() override
 	{
 		shutdown_requested = true;
 	}
 
-	virtual void disconnect()
+	void disconnect() override
 	{
 		disconnect_requested = true;
 	}
 
-	virtual void changePassword()
+	void changePassword() override
 	{
 		changepassword_requested = true;
 	}
 
-	virtual void changeVolume()
+	void changeVolume() override
 	{
 		changevolume_requested = true;
 	}
 
-	virtual void keyConfig()
+	void keyConfig() override
 	{
 		keyconfig_requested = true;
 	}
 
-	virtual void signalKeyConfigChange()
+	void signalKeyConfigChange() override
 	{
 		keyconfig_changed = true;
 	}
 
+	void showOpenURLDialog(const std::string &url) override {
+		show_open_url_dialog = url;
+	}
 
 	bool disconnect_requested = false;
 	bool changepassword_requested = false;
 	bool changevolume_requested = false;
 	bool keyconfig_requested = false;
 	bool shutdown_requested = false;
-
 	bool keyconfig_changed = false;
+	std::string show_open_url_dialog = "";
 };
 
 extern MainGameCallback *g_gamecallback;
diff --git a/src/unittest/test_utilities.cpp b/src/unittest/test_utilities.cpp
index 9ebf3b873..752950abe 100644
--- a/src/unittest/test_utilities.cpp
+++ b/src/unittest/test_utilities.cpp
@@ -24,6 +24,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/numeric.h"
 #include "util/string.h"
 #include "util/base64.h"
+#include "util/colorize.h"
 
 class TestUtilities : public TestBase {
 public:
@@ -59,6 +60,7 @@ public:
 	void testBase64();
 	void testSanitizeDirName();
 	void testIsBlockInSight();
+	void testColorizeURL();
 };
 
 static TestUtilities g_test_instance;
@@ -92,6 +94,7 @@ void TestUtilities::runTests(IGameDef *gamedef)
 	TEST(testBase64);
 	TEST(testSanitizeDirName);
 	TEST(testIsBlockInSight);
+	TEST(testColorizeURL);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -710,3 +713,19 @@ void TestUtilities::testIsBlockInSight()
 		UASSERT(isBlockInSight({-1, 0, 0}, cam_pos, cam_dir, fov, range));
 	}
 }
+
+void TestUtilities::testColorizeURL()
+{
+#ifdef USE_CURL
+	#define RED COLOR_CODE("#faa")
+	#define GREY COLOR_CODE("#aaa")
+	#define WHITE COLOR_CODE("#fff")
+
+	std::string result = colorize_url("http://example.com/");
+	UASSERT(result == (GREY "http://" WHITE "example.com" GREY "/"));
+
+	result = colorize_url(u8"https://u:p@wikipedi\u0430.org:1234/heIIoll?a=b#c");
+	UASSERT(result ==
+		(GREY "https://u:p@" WHITE "wikipedi" RED "%d0%b0" WHITE ".org" GREY ":1234/heIIoll?a=b#c"));
+#endif
+}
diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index d8f106589..68e9eae5f 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -1,6 +1,7 @@
 set(UTIL_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/areastore.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/auth.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/colorize.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/base64.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/directiontables.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/enriched_string.cpp
diff --git a/src/util/colorize.cpp b/src/util/colorize.cpp
new file mode 100644
index 000000000..4cfe46a09
--- /dev/null
+++ b/src/util/colorize.cpp
@@ -0,0 +1,113 @@
+/*
+Part of Minetest
+Copyright (C) 2024 rubenwardy
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "colorize.h"
+
+#ifdef USE_CURL
+
+#include <curl/urlapi.h>
+#include "log.h"
+#include "string.h"
+#include <sstream>
+
+std::string colorize_url(const std::string &url)
+{
+	// Forbid escape codes in URL
+	if (url.find('\x1b') != std::string::npos) {
+		throw std::runtime_error("Unable to open URL as it contains escape codes");
+	}
+
+	auto urlHandleRAII = std::unique_ptr<CURLU, decltype(&curl_url_cleanup)>(
+			curl_url(), curl_url_cleanup);
+	CURLU *urlHandle = urlHandleRAII.get();
+
+	auto rc = curl_url_set(urlHandle, CURLUPART_URL, url.c_str(), 0);
+	if (rc != CURLUE_OK) {
+		throw std::runtime_error("Unable to open URL as it is not valid");
+	}
+
+	auto url_get = [&] (CURLUPart what) -> std::string {
+		char *tmp = nullptr;
+		curl_url_get(urlHandle, what, &tmp, 0);
+		std::string ret(tmp ? tmp : "");
+		curl_free(tmp);
+		return ret;
+	};
+
+	auto scheme = url_get(CURLUPART_SCHEME);
+	auto user = url_get(CURLUPART_USER);
+	auto password = url_get(CURLUPART_PASSWORD);
+	auto host = url_get(CURLUPART_HOST);
+	auto port = url_get(CURLUPART_PORT);
+	auto path = url_get(CURLUPART_PATH);
+	auto query = url_get(CURLUPART_QUERY);
+	auto fragment = url_get(CURLUPART_FRAGMENT);
+	auto zoneid = url_get(CURLUPART_ZONEID);
+
+	std::ostringstream os;
+
+	std::string_view red = COLOR_CODE("#faa");
+	std::string_view white = COLOR_CODE("#fff");
+	std::string_view grey = COLOR_CODE("#aaa");
+
+	os << grey << scheme << "://";
+	if (!user.empty())
+		os << user;
+	if (!password.empty())
+		os << ":" << password;
+	if (!(user.empty() && password.empty()))
+		os << "@";
+
+	// Print hostname, escaping unsafe characters
+	os << white;
+	bool was_alphanum = true;
+	std::string host_s = host;
+	for (size_t i = 0; i < host_s.size(); i++) {
+		char c = host_s[i];
+		bool is_alphanum = isalnum(c) || ispunct(c);
+		if (is_alphanum == was_alphanum) {
+			// skip
+		} else if (is_alphanum) {
+			os << white;
+		} else {
+			os << red;
+		}
+		was_alphanum = is_alphanum;
+
+		if (is_alphanum) {
+			os << c;
+		} else {
+			os << "%" << std::setfill('0') << std::setw(2) << std::hex
+				<< (static_cast<unsigned int>(c) & 0xff);
+		}
+	}
+
+	os << grey;
+	if (!zoneid.empty())
+		os << "%" << zoneid;
+	if (!port.empty())
+		os << ":" << port;
+	os << path;
+	if (!query.empty())
+		os << "?" << query;
+	if (!fragment.empty())
+		os << "#" << fragment;
+
+	return os.str();
+}
+
+#endif
diff --git a/src/util/colorize.h b/src/util/colorize.h
new file mode 100644
index 000000000..dfd1ef921
--- /dev/null
+++ b/src/util/colorize.h
@@ -0,0 +1,34 @@
+/*
+Part of Minetest
+Copyright (C) 2024 rubenwardy
+
+Permission to use, copy, modify, and distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#pragma once
+
+#include <string>
+#include "config.h"
+
+#define COLOR_CODE(color) "\x1b(c@" color ")"
+
+#ifdef USE_CURL
+
+/**
+ * Colorize URL to highlight the hostname and any unsafe characters
+ *
+ * Throws an exception if the url is invalid
+ */
+std::string colorize_url(const std::string &url);
+
+#endif
diff --git a/src/util/string.cpp b/src/util/string.cpp
index 844b6dff8..6c2ae7ca7 100644
--- a/src/util/string.cpp
+++ b/src/util/string.cpp
@@ -593,6 +593,40 @@ void str_replace(std::string &str, char from, char to)
 	std::replace(str.begin(), str.end(), from, to);
 }
 
+std::string wrap_rows(std::string_view from, unsigned row_len, bool has_color_codes)
+{
+	std::string to;
+	to.reserve(from.size());
+	std::string last_color_code;
+
+	unsigned character_idx = 0;
+	bool inside_colorize = false;
+	for (size_t i = 0; i < from.size(); i++) {
+		if (!IS_UTF8_MULTB_INNER(from[i])) {
+			if (inside_colorize) {
+				last_color_code += from[i];
+				if (from[i] == ')') {
+					inside_colorize = false;
+				} else {
+					// keep reading
+				}
+			} else if (has_color_codes && from[i] == '\x1b') {
+				inside_colorize = true;
+				last_color_code = "\x1b";
+			} else {
+				// Wrap string after last inner byte of char
+				if (character_idx > 0 && character_idx % row_len == 0) {
+					to += '\n' + last_color_code;
+				}
+				character_idx++;
+			}
+		}
+		to += from[i];
+	}
+
+	return to;
+}
+
 /* Translated strings have the following format:
  * \x1bT marks the beginning of a translated string
  * \x1bE marks its end
diff --git a/src/util/string.h b/src/util/string.h
index beb75b6d3..0c81a15cb 100644
--- a/src/util/string.h
+++ b/src/util/string.h
@@ -512,7 +512,7 @@ inline bool string_allowed_blacklist(std::string_view str,
  * Create a string based on \p from where a newline is forcefully inserted
  * every \p row_len characters.
  *
- * @note This function does not honour word wraps and blindy inserts a newline
+ * @note This function does not honour word wraps and blindly inserts a newline
  *	every \p row_len characters whether it breaks a word or not.  It is
  *	intended to be used for, for example, showing paths in the GUI.
  *
@@ -521,26 +521,10 @@ inline bool string_allowed_blacklist(std::string_view str,
  *
  * @param from The (utf-8) string to be wrapped into rows.
  * @param row_len The row length (in characters).
+ * @param has_color_codes Whether the source string has colorize codes.
  * @return A new string with the wrapping applied.
  */
-inline std::string wrap_rows(std::string_view from, unsigned row_len)
-{
-	std::string to;
-	to.reserve(from.size());
-
-	unsigned character_idx = 0;
-	for (size_t i = 0; i < from.size(); i++) {
-		if (!IS_UTF8_MULTB_INNER(from[i])) {
-			// Wrap string after last inner byte of char
-			if (character_idx > 0 && character_idx % row_len == 0)
-				to += '\n';
-			character_idx++;
-		}
-		to += from[i];
-	}
-
-	return to;
-}
+std::string wrap_rows(std::string_view from, unsigned row_len, bool has_color_codes = false);
 
 
 /**