Implement going to references in Go to...

src/pyj/read_book/goto.pyj

@@ -86,17 +86,30 @@ def create_location_overlay(current_position_data, overlay, container):
             error_dialog(_('No such location'), _(
                 'No location {} found').format(cfi))
 
+    def goto_ref(ref):
+        if ui_operations.goto_reference(ref):
+            overlay.hide()
+        else:
+            error_dialog(_('No such reference'), _(
+                'No reference {} found').format(ref))
+
     if current_position_data.book_length > 0:
         container.appendChild(
             E.div(style='margin: 1rem', _('Current position: {}').format(
                 format_pos(current_position_data.progress_frac, current_position_data.book_length))))
 
+    container.appendChild(
+        E.div(style='margin: 1rem', _(
+            'Type the position, location or reference below. For a reference type ref: followed by the reference:')))
+
     def goto_pos():
         src = document.querySelector(f'#{container_id} [name=newpos]').value
         if not src:
             return
         if src.indexOf('epubcfi(') is 0:
             return goto_cfi(src)
+        if src.indexOf('ref:') is 0:
+            return goto_ref(src[len('ref:'):])
         try:
             ui_operations.goto_book_position(float(src))
         except:

src/pyj/read_book/overlay.pyj

@@ -646,7 +646,7 @@ class Overlay:
     def show_ask_for_location(self):
         self.hide_current_panel()
         self.panels.push(SimpleOverlay(
-            self, create_location_overlay.bind(None, self.view.current_position_data), _('Go to location or position…')))
+            self, create_location_overlay.bind(None, self.view.current_position_data), _('Go to location, position or reference…')))
         self.show_current_panel()
 
     def show_search(self):

src/pyj/read_book/ui.pyj

@@ -68,6 +68,7 @@ class ReadUI:
         ui_operations.goto_cfi = self.goto_cfi.bind(self)
         ui_operations.goto_frac = self.goto_frac.bind(self)
         ui_operations.goto_book_position = self.goto_book_position.bind(self)
+        ui_operations.goto_book_position = self.goto_reference.bind(self)
         ui_operations.delete_book = self.delete_book.bind(self)
         ui_operations.focus_iframe = self.focus_iframe.bind(self)
         ui_operations.toggle_toc = self.toggle_toc.bind(self)
@@ -170,6 +171,9 @@ class ReadUI:
     def goto_book_position(self, bpos):
         return self.view.goto_book_position(bpos)
 
+    def goto_reference(self, ref):
+        return self.view.goto_reference(ref)
+
     def delete_book(self, book, proceed):
         self.db.delete_book(book, proceed)
 

src/pyj/viewer-main.pyj

@@ -327,6 +327,8 @@ if window is window.top:
         return view.goto_frac(frac)
     ui_operations.goto_book_position = def(bpos):
         return view.goto_book_position(bpos)
+    ui_operations.goto_reference = def(ref):
+        return view.goto_reference(ref)
     ui_operations.toggle_toc = def():
         to_python.toggle_toc()
     ui_operations.toggle_bookmarks = def():