Add OSC 8 hyperlink support

This commit adds support for the OSC 8 hyperlink escape sequence [1]. As
this is not a mature feature and there seem to be outstanding security
concerns [2], the setting that controls whether or not OSC 8 is
interpreted is disabled by default.

Just like gnome-terminal, weltschmerz will display a tooltip with the
canonicalized URI when hovering over a hyperlink.

[1] https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
[2] https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda#security

7 files changed, 96 insertions, 15 deletions

diff --git a/Makefile b/Makefile
index 5822595..cfc8ec9 100644
--- a/Makefile
+++ b/Makefile
@@ -7,7 +7,7 @@ VALAC ?= valac
 
 weltschmerz: weltschmerz.vala terminal.vala config.vala resources.c
 	${VALAC} -X -lm --pkg posix --pkg gtk+-3.0 --pkg vte-2.91 --gresources resources.xml \
-		weltschmerz.vala terminal.vala config.vala configreader.vala resources.c
+		weltschmerz.vala terminal.vala config.vala configreader.vala utils.vala resources.c
 
 resources.c: resources.xml terminal.ui terminal.css
 	glib-compile-resources $< --target=$@ --generate-source
diff --git a/config.vala b/config.vala
index 991d015..be3f353 100644
--- a/config.vala
+++ b/config.vala
@@ -5,6 +5,7 @@ class Config {
 	public Pango.FontDescription font;
 	public int scrollback;
 	public bool scrollbar;
+	public bool allow_hyperlinks;
 
 	public Gdk.RGBA? foreground;
 	public Gdk.RGBA? background;
@@ -46,6 +47,7 @@ class Config {
 		font = Pango.FontDescription.from_string(reader.read_string("misc", "font", "Monospace 12"));
 		scrollback = reader.read_integer("misc", "scrollback", 10000);
 		scrollbar = reader.read_boolean("misc", "scrollbar", true);
+		allow_hyperlinks = reader.read_boolean("misc", "allow-hyperlinks", false);
 
 		foreground = reader.read_colour("colours", "foreground", null);
 		background = reader.read_colour("colours", "background", null);
diff --git a/meson.build b/meson.build
index 485ce8e..dc83f80 100644
--- a/meson.build
+++ b/meson.build
@@ -11,7 +11,7 @@ dependencies = [
   dependency('vte-2.91'),
 ]
 
-sources = files('weltschmerz.vala', 'terminal.vala', 'config.vala', 'configreader.vala')
+sources = files('weltschmerz.vala', 'terminal.vala', 'config.vala', 'configreader.vala', 'utils.vala')
 sources += gnome.compile_resources('resources', 'resources.xml')
 
 executable('weltschmerz', sources, dependencies: dependencies, install: true)
diff --git a/terminal.ui b/terminal.ui
index c82a04d..4ba9555 100644
--- a/terminal.ui
+++ b/terminal.ui
@@ -3,6 +3,28 @@
 <interface>
   <requires lib="gtk+" version="3.20"/>
   <requires lib="vte-2.91" version="0.54"/>
+  <object class="GtkImage" id="copy_hyperlink_image">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="icon_name">edit-copy</property>
+  </object>
+  <object class="GtkMenu" id="hyperlink_context_menu">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <child>
+      <object class="GtkImageMenuItem" id="copy_hyperlink_item">
+        <property name="label" translatable="yes">_Copy hyperlink</property>
+        <property name="visible">True</property>
+        <property name="can_focus">False</property>
+        <property name="tooltip_text" translatable="yes">Copy the hyperlink's URI to the clipboard</property>
+        <property name="use_underline">True</property>
+        <property name="image">copy_hyperlink_image</property>
+        <property name="use_stock">False</property>
+        <property name="always_show_image">True</property>
+        <signal name="activate" handler="uri_copy" swapped="no"/>
+      </object>
+    </child>
+  </object>
   <object class="GtkImage" id="copy_url_image">
     <property name="visible">True</property>
     <property name="can_focus">False</property>
@@ -21,7 +43,7 @@
         <property name="image">copy_url_image</property>
         <property name="use_stock">False</property>
         <property name="always_show_image">True</property>
-        <signal name="activate" handler="url_match_copy" swapped="no"/>
+        <signal name="activate" handler="uri_copy" swapped="no"/>
       </object>
     </child>
   </object>
@@ -58,6 +80,7 @@
             <signal name="button-press-event" handler="vte_button_press" swapped="no"/>
             <signal name="button-release-event" handler="vte_button_release" swapped="no"/>
             <signal name="child-exited" handler="gtk_main_quit" swapped="no"/>
+            <signal name="hyperlink-hover-uri-changed" handler="vte_hyperlink_hover" swapped="no"/>
             <signal name="key-press-event" handler="vte_key_press" swapped="no"/>
             <signal name="scroll-event" handler="vte_scroll" swapped="no"/>
             <signal name="window-title-changed" handler="window_set_title" swapped="no"/>
diff --git a/terminal.vala b/terminal.vala
index 99c21ce..5f4f4e0 100644
--- a/terminal.vala
+++ b/terminal.vala
@@ -25,14 +25,17 @@ class Terminal : Gtk.Overlay {
 	[GtkChild] Gtk.Label infobar_label;
 	[GtkChild] Gtk.Menu standard_context_menu;
 	[GtkChild] Gtk.Menu url_context_menu;
+	[GtkChild] Gtk.Menu hyperlink_context_menu;
 	[GtkChild] Gtk.MenuItem copy_item;
 	[GtkChild] Gtk.Revealer search_revealer;
 	[GtkChild] Gtk.ScrolledWindow scrolled_window;
 	[GtkChild] Gtk.SearchEntry search_entry;
 	[GtkChild] Vte.Terminal vte;
+	Gtk.Clipboard clipboard;
 
 	bool has_search;
 	string url_match;
+	string hyperlink_match;
 	uint? infobar_timeout_id;
 	double scroll_delta;
 
@@ -45,8 +48,11 @@ class Terminal : Gtk.Overlay {
 		vte.search_set_wrap_around(true);
 
 		url_context_menu.attach_to_widget(vte, null);
+		hyperlink_context_menu.attach_to_widget(vte, null);
 		standard_context_menu.attach_to_widget(vte, null);
 
+		clipboard = Gtk.Clipboard.get_default(window.get_display());
+
 		try {
 			var regex = new Vte.Regex.for_match(URL_REGEX, URL_REGEX.length, PCRE2_CASELESS | PCRE2_MULTILINE);
 			vte.match_add_regex(regex, 0);
@@ -69,6 +75,8 @@ class Terminal : Gtk.Overlay {
 		Gtk.PolicyType policy = conf.scrollbar ? Gtk.PolicyType.AUTOMATIC : Gtk.PolicyType.NEVER;
 		scrolled_window.set_policy(policy, policy);
 
+		vte.set_allow_hyperlink(conf.allow_hyperlinks);
+
 		vte.set_font(conf.font);
 		var geometry = Gdk.Geometry() {
 			// This must be kept in sync with the padding size in terminal.css
@@ -262,9 +270,9 @@ class Terminal : Gtk.Overlay {
 		search_button_down.set_sensitive(has_search);
 	}
 
-	void url_match_open() {
+	void uri_open(string uri) {
 		try {
-			AppInfo.launch_default_for_uri(url_match, get_display().get_app_launch_context());
+			AppInfo.launch_default_for_uri(uri, get_display().get_app_launch_context());
 		} catch (Error e) {
 			warning(e.message);
 			infobar_show(e.message, Gtk.MessageType.ERROR);
@@ -272,13 +280,12 @@ class Terminal : Gtk.Overlay {
 	}
 
 	[GtkCallback]
-	void url_match_copy() {
-		if (url_match == null) {
-			return;
+	void uri_copy() {
+		if (url_match != null) {
+			clipboard.set_text(url_match, -1);
+		} else if (hyperlink_match != null) {
+			clipboard.set_text(hyperlink_match, -1);
 		}
-
-		Gtk.Clipboard clipboard = Gtk.Clipboard.get_default(window.get_display());
-		clipboard.set_text(url_match, -1);
 	}
 
 	void adjust_font_scale(double scale) {
@@ -309,9 +316,12 @@ class Terminal : Gtk.Overlay {
 	bool vte_button_press(Gdk.EventButton event) {
 		if (match_button(event, 0, Gdk.BUTTON_SECONDARY)) {
 			url_match = vte.match_check_event(event, null);
+			hyperlink_match = vte.hyperlink_check_event(event);
 
 			if (url_match != null) {
 				url_context_menu.popup_at_pointer(event);
+			} else if (hyperlink_match != null) {
+				hyperlink_context_menu.popup_at_pointer(event);
 			} else {
 				copy_item.set_sensitive(vte.get_has_selection());
 				standard_context_menu.popup_at_pointer(event);
@@ -326,8 +336,12 @@ class Terminal : Gtk.Overlay {
 	bool vte_button_release(Gdk.EventButton event) {
 		if (match_button(event, 0, Gdk.BUTTON_PRIMARY)) {
 			url_match = vte.match_check_event(event, null);
+			hyperlink_match = vte.hyperlink_check_event(event);
+
 			if (url_match != null && !vte.get_has_selection()) {
-				url_match_open();
+				uri_open(url_match);
+			} else if (hyperlink_match != null && !vte.get_has_selection()) {
+				uri_open(hyperlink_match);
 			}
 		}
 
@@ -398,6 +412,11 @@ class Terminal : Gtk.Overlay {
 	}
 
 	[GtkCallback]
+	void vte_hyperlink_hover(string? uri, Gdk.Rectangle? box) {
+		vte.set_tooltip_text(Utils.normalize_uri(uri));
+	}
+
+	[GtkCallback]
 	void window_set_title() {
 		string title = null;
 		if (vte.window_title.length > 0) {
diff --git a/utils.vala b/utils.vala
new file mode 100644
index 0000000..845728b
--- /dev/null
+++ b/utils.vala
@@ -0,0 +1,27 @@
+class Utils {
+	public static string? normalize_uri(string? uri) {
+		if (uri == null)
+			return null;
+
+		string? u = Uri.unescape_string(uri, null);
+
+		if (u == null)
+			u = uri;
+
+		if (u.has_prefix("ftp://") || u.has_prefix("http://") || u.has_prefix("https://")) {
+			int a = u.index_of("/", 0) + 2; // character after second slash
+			int b = u.index_of("/", a); // next slash after hostname...
+			if (b < 0)
+				b = u.length; // ... or end of string
+
+			string hostname = u.slice(a, b);
+			string? canon = Hostname.to_unicode(hostname);
+
+			if (canon != null && hostname != canon) {
+				u = u.splice(a, b, canon);
+			}
+		}
+
+		return u;
+	}
+}
diff --git a/weltschmerz.1 b/weltschmerz.1
index f754253..f2481c8 100644
--- a/weltschmerz.1
+++ b/weltschmerz.1
@@ -1,4 +1,4 @@
-.Dd January 17, 2020
+.Dd March 28, 2020
 .Dt WELTSCHMERZ 1
 .Os
 .Sh NAME
@@ -13,8 +13,8 @@
 .Sh DESCRIPTION
 .Nm
 is a terminal emulator using the VTE widget.
-It supports clickable URLs, contains basic search functionality, and can
-reload its configuration whilst running.
+It supports clickable URLs and hyperlinks, contains basic search functionality,
+and can reload its configuration whilst running.
 .Pp
 .Nm
 executes the given command, or the program specified in the
@@ -82,6 +82,16 @@ The options for the
 .Em misc
 group are as follows:
 .Bl -tag -width Ds
+.It Sy allow-hyperlinks
+When set to
+.Sy true ,
+.Nm
+will highlight and process OSC 8 hyperlinks.
+When set to
+.Sy false ,
+hyperlink support will be disabled completely.
+The default is
+.Sy false .
 .It Sy autohide-mouse
 When set to
 .Sy true ,