Tag browser 'Find' improvements:

- Add exact match searching by using '=' as prefix, as in "=Science Fiction"
- Add option to show only categories containing items, as if a '*' prefix had been used
- Override the collapse option using a prefix of ':', as in :foo
- Make Quickview use exact match searching when items are double-clicked

src/calibre/gui2/__init__.py

@@ -150,6 +150,7 @@ def create_defs():
     defs['ui_style'] = 'calibre' if iswindows or isosx else 'system'
     defs['tag_browser_old_look'] = False
     defs['tag_browser_hide_empty_categories'] = False
+    defs['tag_browser_always_autocollapse'] = False
     defs['book_list_tooltips'] = True
     defs['show_layout_buttons'] = False
     defs['bd_show_cover'] = True

src/calibre/gui2/dialogs/quickview.py

@@ -281,7 +281,7 @@ class Quickview(QDialog, Ui_Quickview):
     def item_doubleclicked(self, item):
         tb = self.gui.stack.tb_widget
         tb.set_focus_to_find_box()
-        tb.item_search.lineEdit().setText(self.current_key + ':' + item.text())
+        tb.item_search.lineEdit().setText(self.current_key + ':=' + item.text())
         tb.do_find()
 
     def show_context_menu(self, point):

src/calibre/gui2/preferences/look_feel.py

@@ -412,6 +412,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         r('row_numbers_in_book_list', gprefs)
         r('tag_browser_old_look', gprefs)
         r('tag_browser_hide_empty_categories', gprefs)
+        r('tag_browser_always_autocollapse', gprefs)
         r('tag_browser_show_tooltips', gprefs)
         r('bd_show_cover', gprefs)
         r('bd_overlay_cover_size', gprefs)

src/calibre/gui2/preferences/look_feel.ui

@@ -995,6 +995,18 @@ then the tags will be displayed each on their own line.</string>
          </property>
         </widget>
        </item>
+       <item row="13" column="0" colspan="2">
+        <widget class="QCheckBox" name="opt_tag_browser_always_autocollapse">
+         <property name="toolTip">
+          <string>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.</string>
+         </property>
+         <property name="text">
+          <string>Find &amp;shows all items that match in the Tag browser</string>
+         </property>
+        </widget>
+       </item>
        <item row="1" column="1">
         <widget class="QComboBox" name="opt_tags_browser_partition_method">
          <property name="toolTip">

src/calibre/gui2/tag_browser/model.py

@@ -994,9 +994,19 @@ class TagsModel(QAbstractItemModel):  # {{{
             self.restriction_error.emit()
 
         if self.filter_categories_by:
+            if self.filter_categories_by.startswith('='):
+                use_exact_match = True
+                filter_by = self.filter_categories_by[1:]
+            else:
+                use_exact_match = False
+                filter_by = self.filter_categories_by
             for category in data.keys():
+                if use_exact_match:
                     data[category] = [t for t in data[category]
-                        if lower(t.name).find(self.filter_categories_by) >= 0]
+                        if lower(t.name) == filter_by]
+                else:
+                    data[category] = [t for t in data[category]
+                        if lower(t.name).find(filter_by) >= 0]
 
         # Build a dict of the keys that have data
         tb_categories = self.db.field_metadata

src/calibre/gui2/tag_browser/ui.py

@@ -429,13 +429,16 @@ class TagBrowserBar(QWidget):  # {{{
         self.item_search.setSizeAdjustPolicy(self.item_search.AdjustToMinimumContentsLengthWithIcon)
         self.item_search.initialize('tag_browser_search')
         self.item_search.completer().setCaseSensitivity(Qt.CaseSensitive)
-        self.item_search.setToolTip(_(
-        'Search for items. This is a "contains" search; items containing the\n'
-        'text anywhere in the name will be found. You can limit the search\n'
-        'to particular categories using syntax similar to search. For example,\n'
-        'tags:foo will find foo in any tag, but not in authors etc. Entering\n'
-        '*foo will filter all categories at once, showing only those items\n'
-        'containing the text "foo"'))
+        self.item_search.setToolTip(
+            '<p>' +_(
+                'Search for items. If the text begins with equals (=) the search is '
+                'exact match, otherwise it is "contains" finding items containing '
+                'the text anywhere in the item name. Both exact and contains '
+                'searches ignore case. You can limit the search to particular '
+                'categories using syntax similar to search. For example, '
+                'tags:foo will find foo in any tag, but not in authors etc. Entering '
+                '*foo will collapse all categories then showing only those categories '
+                'with items containing the text "foo"') + '</p')
         ac = QAction(parent)
         parent.addAction(ac)
         parent.keyboard.register_shortcut('tag browser find box',
@@ -639,8 +642,32 @@ class TagBrowserWidget(QFrame):  # {{{
     def find(self):
         model = self.tags_view.model()
         model.clear_boxed()
-        txt = self.find_text
 
+        # When a key is specified don't use the auto-collapsing search.
+        # A colon separates the lookup key from the search string.
+        # A leading colon says not to use autocollapsing search but search all keys
+        txt = self.find_text
+        colon = txt.find(':')
+        if colon >= 0:
+            key = self._parent.library_view.model().db.\
+                        field_metadata.search_term_to_field_key(txt[:colon])
+            if key in self._parent.library_view.model().db.field_metadata:
+                txt = txt[colon+1:]
+            else:
+                key = ''
+                txt = txt[1:] if colon == 0 else txt
+        else:
+            key = None
+
+        # key is None indicates that no colon was found.
+        # key == '' means either a leading : was found or the key is invalid
+
+        # At this point the txt might have a leading =, in which case do an
+        # exact match search
+
+        if (gprefs.get('tag_browser_always_autocollapse', False) and
+                key is None and not txt.startswith('*')):
+            txt = '*' + txt
         if txt.startswith('*'):
             self.tags_view.collapseAll()
             model.set_categories_filter(txt[1:])
@@ -659,18 +686,14 @@ class TagBrowserWidget(QFrame):  # {{{
         self.search_button.setFocus(True)
         self.item_search.lineEdit().blockSignals(False)
 
-        key = None
-        colon = txt.find(':') if len(txt) > 2 else 0
-        if colon > 0:
-            key = self._parent.library_view.model().db.\
-                        field_metadata.search_term_to_field_key(txt[:colon])
-            if key in self._parent.library_view.model().db.field_metadata:
-                txt = txt[colon+1:]
+        if txt.startswith('='):
+            equals_match = True
+            txt = txt[1:]
         else:
-                key = None
-
+            equals_match = False
         self.current_find_position = \
-            model.find_item_node(key, txt, self.current_find_position)
+            model.find_item_node(key, txt, self.current_find_position,
+                                 equals_match=equals_match)
 
         if self.current_find_position:
             self.tags_view.show_item_at_path(self.current_find_position, box=True)