Edit Book: Add keyboard shortcuts to jumpt to opening and closing tag…

…s (Ctrl+{ and Ctrl+})

manual/edit.rst

@@ -837,3 +837,12 @@ text. The editor allows you to insert a snippet with only a few key strokes.
 The snippets are very powerful, with many features, such as placeholders you
 can jump between, automatic mirroring of repeated text and so on.
 For more information, see :doc:`snippets`.
+
+
+Matching tags
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+When editing HTML or XML files, the closest tag containing the current cursor
+position is automatically highlighted. You can jump to either the opening tag
+or the closing tag using the keyboard shortcuts, :kbd:`Ctrl+{` and
+:kbd:`Ctrl+}`.

src/calibre/gui2/tweak_book/editor/smarts/html.py

@@ -311,7 +311,7 @@ def __init__(self, *args, **kwargs):
             Smarts.self_closing_pat = re.compile(r'/\s*>')
             Smarts.complete_attr_pat = re.compile(r'''([a-zA-Z0-9_-]+)\s*=\s*(?:'([^']*)|"([^"]*))$''')
         NullSmarts.__init__(self, *args, **kwargs)
-        self.last_matched_tag = None
+        self.last_matched_tag = self.last_matched_closing_tag = None
 
     def get_extra_selections(self, editor):
         ans = []
@@ -332,13 +332,24 @@ def add_tag(tag):
         c = editor.textCursor()
         block, offset = c.block(), c.positionInBlock()
         tag = self.last_matched_tag = find_closest_containing_tag(block, offset, max_tags=2000)
+        self.last_matched_closing_tag = None
         if tag is not None:
             add_tag(tag)
-            tag = find_closing_tag(tag, max_tags=4000)
+            tag = self.last_matched_closing_tag = find_closing_tag(tag, max_tags=4000)
             if tag is not None:
                 add_tag(tag)
         return ans
 
+    def jump_to_enclosing_tag(self, editor, start=True):
+        editor.highlighter.join()
+        tag = self.last_matched_tag if start else self.last_matched_closing_tag
+        if tag is None:
+            return False
+        c = editor.textCursor()
+        c.setPosition(tag.start_block.position() + tag.start_offset + (1 if start else 2))
+        editor.setTextCursor(c)
+        return True
+
     def rename_block_tag(self, editor, new_name):
         editor.highlighter.join()
         c = editor.textCursor()
@@ -621,6 +632,12 @@ def handle_key_press(self, ev, editor):
         if key == Qt.Key_Backspace and smart_backspace(editor, ev):
             return True
 
+        if key in (Qt.Key_BraceLeft, Qt.Key_BraceRight):
+            mods = ev.modifiers()
+            if int(mods & Qt.ControlModifier):
+                if self.jump_to_enclosing_tag(editor, key == Qt.Key_BraceLeft):
+                    return True
+
         return False
 
     def replace_possible_entity(self, editor):