The tag browser notes/links icon stuff.

Clicking the "buttons" works because of how mouse tracking works. The user must move the mouse over/into the current item line before clicking a button, which causes that line to be painted. When the line is painted the horizontal positions of the buttons on the line are recorded. If/when a click happens, the click X point is checked to see if it is in the ranges defined by the horizontal positions.

src/calibre/gui2/__init__.py

@@ -423,6 +423,8 @@ def create_defs():
     defs['tb_search_order'] = {'0': 1, '1': 2, '2': 3, '3': 4, '4': 0}
     defs['search_tool_bar_shows_text'] = True
     defs['allow_keyboard_search_in_library_views'] = True
+    defs['show_links_in_tag_brouser'] = False
+    defs['show_notes_in_tag_brouser'] = False
 
     def migrate_tweak(tweak_name, pref_name):
         # If the tweak has been changed then leave the tweak in the file so

src/calibre/gui2/preferences/look_feel.py

@@ -646,6 +646,8 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         r('language', prefs, choices=choices, restart_required=True, setting=LanguageSetting)
 
         r('show_avg_rating', config)
+        r('show_links_in_tag_brouser', gprefs)
+        r('show_notes_in_tag_brouser', gprefs)
         r('disable_animations', config)
         r('systray_icon', config, restart_required=True)
         r('show_splash_screen', gprefs)

src/calibre/gui2/preferences/look_feel.ui

@@ -1290,66 +1290,99 @@ structure and you want to use the same column order for each one.&lt;/p&gt;</str
           </item>
          </layout>
         </item>
-        <item row="5" column="0">
-         <widget class="QCheckBox" name="opt_show_avg_rating">
-          <property name="text">
-           <string>Show &amp;average ratings</string>
-          </property>
-          <property name="checked">
-           <bool>true</bool>
-          </property>
-         </widget>
-        </item>
-        <item row="5" column="2">
-         <widget class="QCheckBox" name="opt_tag_browser_show_tooltips">
-          <property name="text">
-           <string>Show &amp;tooltips</string>
-          </property>
-         </widget>
-        </item>
-        <item row="6" column="0">
-         <widget class="QCheckBox" name="opt_tag_browser_show_counts">
-          <property name="toolTip">
-           <string>&lt;p&gt;Show counts for items in the Tag browser. Such as the number of books
+        <item row="5" column="0" colspan="3">
+         <layout class="QGridLayout" name="gridlayout_22">
+          <item row="0" column="0">
+           <widget class="QCheckBox" name="opt_show_avg_rating">
+            <property name="text">
+             <string>Show &amp;average ratings</string>
+            </property>
+            <property name="toolTip">
+             <string>Show the average rating per item indication in the Tag browser</string>
+            </property>
+            <property name="checked">
+             <bool>true</bool>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="1">
+           <widget class="QCheckBox" name="opt_show_links_in_tag_brouser">
+            <property name="text">
+             <string>Show &amp;links icons</string>
+            </property>
+            <property name="toolTip">
+             <string>Show an icon if the item has an attached link</string>
+            </property>
+            <property name="checked">
+             <bool>true</bool>
+            </property>
+           </widget>
+          </item>
+          <item row="0" column="2">
+           <widget class="QCheckBox" name="opt_tag_browser_show_tooltips">
+            <property name="text">
+             <string>Show &amp;tooltips</string>
+            </property>
+           </widget>
+          </item>
+          <item row="1" column="0">
+           <widget class="QCheckBox" name="opt_tag_browser_show_counts">
+            <property name="toolTip">
+             <string>&lt;p&gt;Show counts for items in the Tag browser. Such as the number of books
 by each author, the number of authors, etc. If you turn it off, you can still
 see the counts by hovering your mouse over any item.&lt;/p&gt;</string>
-          </property>
-          <property name="text">
-           <string>Show &amp;counts</string>
-          </property>
-         </widget>
-        </item>
-        <item row="6" column="2">
-         <widget class="QCheckBox" name="opt_tag_browser_old_look">
-          <property name="text">
-           <string>Use &amp;alternating row colors</string>
-          </property>
-         </widget>
-        </item>
-        <item row="7" column="0">
-         <widget class="QCheckBox" name="opt_tag_browser_hide_empty_categories">
-          <property name="toolTip">
-           <string>&lt;p&gt;When checked, calibre will automatically hide any category
+            </property>
+            <property name="text">
+             <string>Show &amp;counts</string>
+            </property>
+           </widget>
+          </item>
+          <item row="1" column="1">
+           <widget class="QCheckBox" name="opt_show_notes_in_tag_brouser">
+            <property name="text">
+             <string>Show &amp;notes icons</string>
+            </property>
+            <property name="toolTip">
+             <string>Show an icon if the item has an attached note</string>
+            </property>
+            <property name="checked">
+             <bool>true</bool>
+            </property>
+           </widget>
+          </item>
+          <item row="1" column="2">
+           <widget class="QCheckBox" name="opt_tag_browser_old_look">
+            <property name="text">
+             <string>Use &amp;alternating row colors</string>
+            </property>
+           </widget>
+          </item>
+          <item row="2" column="0">
+           <widget class="QCheckBox" name="opt_tag_browser_hide_empty_categories">
+            <property name="toolTip">
+             <string>&lt;p&gt;When checked, calibre will automatically hide any category
 (a column, custom or standard) that has no items to show. For example, some
 categories might not have values when using Virtual libraries. Checking this
 box will cause these empty categories to be hidden.&lt;/p&gt;</string>
-          </property>
-          <property name="text">
-           <string>Hide empt&amp;y categories (columns)</string>
-          </property>
-         </widget>
-        </item>
-        <item row="7" column="2">
-         <widget class="QCheckBox" name="opt_tag_browser_always_autocollapse">
-          <property name="toolTip">
-           <string>&lt;p&gt;When checked, Find in the Tag browser will show all items
+            </property>
+            <property name="text">
+             <string>Hide empt&amp;y categories (columns)</string>
+            </property>
+           </widget>
+          </item>
+          <item row="2" column="2">
+           <widget class="QCheckBox" name="opt_tag_browser_always_autocollapse">
+            <property name="toolTip">
+             <string>&lt;p&gt;When checked, Find in the Tag browser will show all items
 that match the search instead of the first one. If Hide empty categories is
 also checked then only categories containing a matched item will be shown.&lt;/p&gt;</string>
-          </property>
-          <property name="text">
-           <string>Find &amp;shows all items that match</string>
-          </property>
-         </widget>
+            </property>
+            <property name="text">
+             <string>Find &amp;shows all items that match</string>
+            </property>
+           </widget>
+          </item>
+         </layout>
         </item>
         <item row="8" column="0" colspan="3">
          <layout class="QVBoxLayout" name="verticalLayout">

src/calibre/gui2/tag_browser/model.py

@@ -235,10 +235,16 @@ class TagTreeItem:  # {{{
                 ar = self.average_rating
                 if ar:
                     tt.append(_('Average rating for books in this category: %.1f') % ar)
-                elif self.type == self.TAG and ar is not None:
-                    tt.append(_('Books in this category are unrated'))
-                if self.type == self.TAG and tag.category != 'search':
-                    tt.append(_('Number of books: %s') % self.item_count)
+                elif self.type == self.TAG:
+                    if ar is not None:
+                        tt.append(_('Books in this category are unrated'))
+                    if tag.category != 'search':
+                        tt.append(_('Number of books: %s') % self.item_count)
+                    from calibre.gui2.ui import get_gui
+                    db = get_gui().current_db.new_api
+                    link = db.get_link_map(tag.category).get(tag.original_name)
+                    if link:
+                        tt.append(_('Link: %s') % link)
                 return '\n'.join(tt)
             return None
         if role == DRAG_IMAGE_ROLE:
@@ -365,6 +371,7 @@ class TagsModel(QAbstractItemModel):  # {{{
         self._build_in_progress = False
         self.reread_collapse_model({}, rebuild=False)
         self.show_error_after_event_loop_tick_signal.connect(self.on_show_error_after_event_loop_tick, type=Qt.ConnectionType.QueuedConnection)
+        self.reset_notes_and_link_maps()
 
     @property
     def gui_parent(self):
@@ -441,6 +448,43 @@ class TagsModel(QAbstractItemModel):  # {{{
         self._run_rebuild()
         self.endResetModel()
 
+    def _cached_notes_map(self, category):
+        if self.notes_map is None:
+            self.notes_map = {}
+        if category not in self.notes_map:
+            try:
+                self.notes_map[category] = (self.db.new_api.get_all_items_that_have_notes(category),
+                                            self.db.new_api.get_item_name_map(category))
+            except:
+                self.notes_map[category] = (frozenset(), {})
+        return self.notes_map[category]
+
+    def _cached_link_map(self, category):
+        if self.link_map is None:
+            self.link_map = {}
+        if category not in self.link_map:
+            try:
+                self.link_map[category] = self.db.new_api.get_link_map(category)
+            except Exception:
+                self.link_map[category] = {}
+        return self.link_map[category]
+
+    def category_has_notes(self, category):
+        return len(self._cached_notes_map(category)[0]) > 0
+
+    def item_has_note(self, category, item_name):
+        notes_map, item_id_map = self._cached_notes_map(category)
+        return item_id_map.get(item_name) in notes_map
+
+    def category_has_links(self, category):
+        return len(self._cached_link_map(category)) > 0
+
+    def item_has_link(self, category, item_name):
+        return item_name in self._cached_link_map(category)
+
+    def reset_notes_and_link_maps(self):
+        self.link_map = self.notes_map = None
+
     def rebuild_node_tree(self, state_map={}):
         if self._build_in_progress:
             print('Tag browser build already in progress')
@@ -455,6 +499,7 @@ class TagsModel(QAbstractItemModel):  # {{{
         self._build_in_progress = False
 
     def _run_rebuild(self, state_map={}):
+        self.reset_notes_and_link_maps()
         for node in itervalues(self.node_map):
             node.break_cycles()
         del node  # Clear reference to node in the current frame

src/calibre/gui2/tag_browser/ui.py

@@ -514,6 +514,7 @@ class TagBrowserMixin:  # {{{
         m = self.library_view.model()
         ids = [m.id(r) for r in rows]
 
+        self.tags_view.model().reset_notes_and_link_maps()
         m.refresh(reset=False)
         m.research()
         self.library_view.select_rows(ids)

src/calibre/gui2/tag_browser/view.py

@@ -22,7 +22,7 @@ from calibre.constants import config_dir
 from calibre.ebooks.metadata import rating_to_stars
 from calibre.gui2 import (
     FunctionDispatcher, choose_files, config, empty_index, gprefs, pixmap_to_data,
-    question_dialog, rating_font,
+    question_dialog, rating_font, safe_open_url,
 )
 from calibre.gui2.dialogs.edit_category_notes import EditNoteDialog
 from calibre.gui2.complete2 import EditWithComplete
@@ -43,6 +43,9 @@ class TagDelegate(QStyledItemDelegate):  # {{{
         self.rating_pat = re.compile(r'[%s]' % rating_to_stars(3, True))
         self.rating_font = QFont(rating_font())
         self.tags_view = tags_view
+        self.links_icon = QIcon.ic('external-link.png')
+        self.notes_icon = QIcon.ic('notes.png')
+        self.blank_icon = QIcon()
 
     def draw_average_rating(self, item, style, painter, option, widget):
         rating = item.average_rating
@@ -86,6 +89,30 @@ class TagDelegate(QStyledItemDelegate):  # {{{
         hover = option.state & QStyle.StateFlag.State_MouseOver
         is_search = (True if item.type == TagTreeItem.TAG and
                             item.tag.category == 'search' else False)
+
+        show_notes = gprefs['show_notes_in_tag_brouser']
+        show_links = gprefs['show_links_in_tag_brouser']
+        if item.type == TagTreeItem.TAG:
+            category = item.tag.category
+            name = item.tag.original_name
+            m = self.tags_view._model
+            if show_notes and m.category_has_notes(category):
+                icon = self.notes_icon if m.item_has_note(category, name) else self.blank_icon
+                width = int(tr.height()/2)
+                r = QRect(tr)
+                r.setRight(r.right() - 1), r.setLeft(r.right() - width - 4)
+                self.tags_view.current_note_button_position = (r.left(), r.left()+r.width())
+                icon.paint(painter, r, option.decorationAlignment, QIcon.Mode.Normal, QIcon.State.On)
+                tr.setRight(r.left() - 1)
+
+            if show_links and m.category_has_links(category):
+                icon = self.links_icon if m.item_has_link(category, name) else self.blank_icon
+                width = int(tr.height()/2)
+                r = QRect(tr)
+                r.setRight(r.right() - 1), r.setLeft(r.right() - width - 4)
+                self.tags_view.current_link_button_position = (r.left(), r.left()+r.width())
+                icon.paint(painter, r, option.decorationAlignment, QIcon.Mode.Normal, QIcon.State.On)
+                tr.setRight(r.left() - 1)
         if not is_search and (hover or gprefs['tag_browser_show_counts']):
             count = str(index.data(COUNT_ROLE))
             width = painter.fontMetrics().boundingRect(count).width()
@@ -202,6 +229,8 @@ class TagsView(QTreeView):  # {{{
         self.setTabKeyNavigation(True)
         self.setAnimated(True)
         self.setHeaderHidden(True)
+        self.current_note_button_position = (-1, -1)
+        self.current_link_button_position = (-1, -1)
         self.setItemDelegate(TagDelegate(tags_view=self))
         self.made_connections = False
         self.setAcceptDrops(True)
@@ -428,10 +457,29 @@ class TagsView(QTreeView):  # {{{
         except:
             pass
 
+    def number_in_range(self, val, range_tuple):
+        return range_tuple[0] <= val <= range_tuple[1]
+
     def mousePressEvent(self, event):
         if event.buttons() & Qt.MouseButton.LeftButton:
             # Only remember a possible drag start if the item is drag enabled
             dex = self.indexAt(event.pos())
+            t = self._model.data(dex, Qt.UserRole)
+            if t.type == TagTreeItem.TAG:
+                db = self._model.db.new_api
+                tag = t.tag
+                x = event.pos().x()
+                if self.number_in_range(x, self.current_note_button_position):
+                    from calibre.gui2.dialogs.show_category_note import ShowNoteDialog
+                    item_id = db.get_item_id(tag.category, tag.original_name)
+                    if db.notes_for(tag.category, item_id):
+                        ShowNoteDialog(tag.category, item_id, db, parent=self).show()
+                        return
+                elif self.number_in_range(x, self.current_link_button_position):
+                    link = db.get_link_map(tag.category).get(tag.original_name)
+                    if link:
+                        safe_open_url(link)
+                        return
             if self._model.flags(dex) & Qt.ItemFlag.ItemIsDragEnabled:
                 self.possible_drag_start = event.pos()
             else:
@@ -811,6 +859,19 @@ class TagsView(QTreeView):  # {{{
                             self.context_menu.addAction(_('Edit link for %s')%display_name(tag),
                                     partial(self.context_menu_handler,
                                             action='edit_author_link', index=tag.id)).setIcon(QIcon.ic('insert-link.png'))
+                        elif self.db.new_api.has_link_map(key):
+                            self.context_menu.addAction(_('Edit link for %s')%display_name(tag),
+                                    partial(self.context_menu_handler, action='open_editor',
+                                            category=tag.original_name if tag else None,
+                                            key=key))
+
+                        if self.db.new_api.field_supports_notes(key):
+                            item_id = self.db.new_api.get_item_id(tag.category, tag.original_name)
+                            has_note = self._model.item_has_note(key, tag.original_name) #bool(self.db.new_api.notes_for(tag.category, item_id))
+                            self.context_menu.addAction(self.edit_metadata_icon,
+                                (_('Edit note for %s') if has_note else _('Create note for %s'))%display_name(tag),
+                                partial(self.context_menu_handler, action='edit_note',
+                                        index=index, extra=item_id, category=tag.category))
 
                         # is_editable is also overloaded to mean 'can be added
                         # to a User category'
@@ -848,14 +909,6 @@ class TagsView(QTreeView):  # {{{
                             m.addAction(self.minus_icon,
                                 _('Remove %s from selected books') % display_name(tag),
                                 partial(self.context_menu_handler, action='remove_tag', index=index))
-
-                        item_id = self.db.new_api.get_item_id(tag.category, tag.original_name)
-                        has_note = bool(self.db.new_api.notes_for(tag.category, item_id))
-                        self.context_menu.addAction(self.edit_metadata_icon,
-                            (_('Edit note for %s') if has_note else _('Create note for %s'))%display_name(tag),
-                            partial(self.context_menu_handler, action='edit_note',
-                                    index=index, extra=item_id, category=tag.category))
-
                     elif key == 'search' and tag.is_searchable:
                         self.context_menu.addAction(self.rename_icon,
                                                     _('Rename %s')%display_name(tag),