event-popover: Support the maps URI for opening locations

Open gnome-maps (or other map application) when clicking on a map icon
next to the location address.

Resolves: https://gitlab.gnome.org/GNOME/gnome-calendar/-/issues/326
Signed-off-by: Alistair Francis <alistair@alistair23.me>
Part-of: <https://gitlab.gnome.org/GNOME/gnome-calendar/-/merge_requests/590>

src/gui/gcal-event-popover.blp

@@ -138,25 +138,43 @@ template $GcalEventPopover: Popover {
         Separator {}
 
         Box {
-          orientation: vertical;
           margin-top: 12;
           margin-bottom: 12;
           margin-start: 18;
           margin-end: 18;
+          spacing: 12;
 
-          Label {
-            halign: start;
-            label: _("Location");
+          Box {
+            orientation: vertical;
 
-            styles [
-              "heading",
-            ]
+            Label {
+              halign: start;
+              label: _("Location");
+
+              styles [
+                "heading",
+              ]
+            }
+
+            Label location_label {
+              halign: start;
+              selectable: true;
+              ellipsize: end;
+            }
           }
 
-          Label location_label {
-            halign: start;
-            selectable: true;
-            ellipsize: end;
+          Button {
+            halign: end;
+            hexpand: true;
+            valign: center;
+            tooltip-text: _("Open Location");
+            icon-name: "map-symbolic";
+
+            styles [
+              "circular",
+            ]
+
+            clicked => $on_map_button_clicked_cb(template) not-swapped;
           }
         }
       }

src/gui/gcal-event-popover.c

@@ -642,6 +642,31 @@ on_join_meeting_cb (GcalMeetingRow   *meeting_row,
                            g_object_ref (self));
 }
 
+static void
+on_map_button_clicked_cb (GtkButton        *action_button,
+                          GcalEventPopover *self)
+{
+  g_autoptr (GtkUriLauncher) uri_launcher = NULL;
+  g_autofree gchar *location = NULL;
+  g_autofree gchar *uri = NULL;
+  GtkWindow *window;
+
+  window = GTK_WINDOW (gtk_widget_get_root (GTK_WIDGET (self)));
+  g_assert (window != NULL);
+
+  location = g_strdup (gcal_event_get_location (self->event));
+  g_strstrip (location);
+
+  uri = g_strconcat ("maps:q=", location, NULL);
+  g_assert (g_uri_is_valid (uri, G_URI_FLAGS_NONE, NULL));
+  uri_launcher = gtk_uri_launcher_new (uri);
+  gtk_uri_launcher_launch (uri_launcher,
+                           window,
+                           NULL,
+                           on_uri_launched_cb,
+                           g_object_ref (self));
+}
+
 static void
 on_time_format_changed_cb (GcalEventPopover *self)
 {
@@ -771,6 +796,7 @@ gcal_event_popover_class_init (GcalEventPopoverClass *klass)
 
   gtk_widget_class_bind_template_callback (widget_class, on_action_button_clicked_cb);
   gtk_widget_class_bind_template_callback (widget_class, on_ics_export_button_clicked_cb);
+  gtk_widget_class_bind_template_callback (widget_class, on_map_button_clicked_cb);
 }
 
 static void

src/gui/icons/icons.gresource.xml

@@ -16,5 +16,6 @@
     <file compressed="true">info-outline-symbolic.svg</file>
     <file compressed="true">loupe-large-symbolic.svg</file>
     <file compressed="true">share-symbolic.svg</file>
+    <file compressed="true">map-symbolic.svg</file>
   </gresource>
 </gresources>

src/gui/icons/map-symbolic.svg

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" height="16px" viewBox="0 0 16 16" width="16px"><path d="m 15 2 v 10 l -5 3 l -5 -3 l -5 3 v -10 l 5 -3 l 5 3 z m -10 1 v 8 l 5 3 v -8 z m 0 0" fill="#222222"/></svg>