Wire up the completion worker into the editor widget

src/calibre/gui2/tweak_book/boss.py

@@ -83,7 +83,8 @@ class Boss(QObject):
         setup_cssutils_serialization()
         _boss = self
         self.gui = parent
-        completion_worker()
+        completion_worker().result_callback = self.handle_completion_result
+        self.completion_request_count = 0
 
     def __call__(self, gui):
         self.gui = gui
@@ -671,6 +672,17 @@ class Boss(QObject):
         ' Mark the book as having been modified '
         self.gui.action_save.setEnabled(True)
 
+    def request_completion(self, name, completion_type, completion_data, query=None):
+        request_id = (self.completion_request_count, name)
+        self.completion_request_count += 1
+        completion_worker().queue_completion(request_id, completion_type, completion_data, query)
+
+    def handle_completion_result(self, result):
+        name = result.request_id[1]
+        editor = editors.get(name)
+        if editor is not None:
+            editor.handle_completion_result(result)
+
     def fix_html(self, current):
         if current:
             ed = self.gui.central.current_editor
@@ -1164,6 +1176,8 @@ class Boss(QObject):
             editor.link_clicked.connect(self.editor_link_clicked)
         if getattr(editor, 'syntax', None) == 'html':
             editor.smart_highlighting_updated.connect(self.gui.live_css.sync_to_editor)
+        if hasattr(editor, 'set_request_completion'):
+            editor.set_request_completion(partial(self.request_completion, name), name)
         if data is not None:
             if use_template:
                 editor.init_from_template(data)

src/calibre/gui2/tweak_book/completion/basic.py

@@ -79,7 +79,7 @@ class HandleDataRequest(QObject):
 
     # Ensure data is obtained in the GUI thread
 
-    call = pyqtSignal(object, object, object)
+    call = pyqtSignal(object, object)
 
     def __init__(self):
         QObject.__init__(self)

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

@@ -33,3 +33,6 @@ class NullSmarts(object):
 
     def handle_key_press(self, ev, editor):
         return False
+
+    def get_completion_data(self, editor, ev=None):
+        return None

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

@@ -16,7 +16,7 @@ from calibre import prepare_string_for_xml, xml_entity_to_unicode
 from calibre.gui2 import error_dialog
 from calibre.gui2.tweak_book.editor.syntax.html import ATTR_NAME, ATTR_END, ATTR_START, ATTR_VALUE
 from calibre.utils.icu import utf16_length
-from calibre.gui2.tweak_book import tprefs
+from calibre.gui2.tweak_book import tprefs, current_container
 from calibre.gui2.tweak_book.editor.smarts import NullSmarts
 from calibre.gui2.tweak_book.editor.smarts.utils import (
     no_modifiers, get_leading_whitespace_on_block, get_text_before_cursor,
@@ -288,6 +288,7 @@ class Smarts(NullSmarts):
             Smarts.closing_tag_pat = re.compile(r'<\s*/[^>]+>')
             Smarts.closing_pat = re.compile(r'<\s*/')
             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
 
@@ -625,7 +626,29 @@ class Smarts(NullSmarts):
         editor.setTextCursor(c)
         return True
 
-if __name__ == '__main__':
+    def get_completion_data(self, editor, ev=None):
+        c = editor.textCursor()
+        block, offset = c.block(), c.positionInBlock()
+        oblock, boundary = next_tag_boundary(block, offset, forward=False)
+        if boundary is None or not boundary.is_start or boundary.closing:
+            # Not inside a opening tag definition
+            return
+        tagname = boundary.name.lower()
+        startpos = oblock.position() + boundary.offset
+        c.setPosition(c.position()), c.setPosition(startpos, c.KeepAnchor)
+        text = c.selectedText()
+        m = self.complete_attr_pat.search(text)
+        if m is None:
+            return
+        attr = m.group(1).lower().split(':')[-1]
+        doc_name = editor.highlighter.doc_name
+        if doc_name and attr in {'href', 'src'}:
+            # A link
+            query = m.group(2) or m.group(3)
+            names_type = {'a':'text_link', 'img':'image', 'image':'image', 'link':'stylesheet'}.get(tagname)
+            return 'complete_names', (names_type, doc_name, current_container().root), query
+
+if __name__ == '__main__':  # {{{
     from calibre.gui2.tweak_book.editor.widget import launch_editor
     launch_editor('''\
 <!DOCTYPE html>
@@ -657,3 +680,4 @@ if __name__ == '__main__':
     </body>
 </html>
 ''', path_is_raw=True, syntax='xml')
+# }}}

src/calibre/gui2/tweak_book/editor/text.py

@@ -19,6 +19,7 @@ from PyQt5.Qt import (
 from calibre import prepare_string_for_xml
 from calibre.constants import isosx
 from calibre.gui2.tweak_book import tprefs, TOP
+from calibre.gui2.tweak_book.completion.popup import CompletionPopup
 from calibre.gui2.tweak_book.editor import (
     SYNTAX_PROPERTY, SPELL_PROPERTY, SPELL_LOCALE_PROPERTY, store_locale, LINK_PROPERTY)
 from calibre.gui2.tweak_book.editor.themes import get_theme, theme_color, theme_format
@@ -138,6 +139,8 @@ class TextEdit(PlainTextEdit):
 
     def __init__(self, parent=None, expected_geometry=(100, 50)):
         PlainTextEdit.__init__(self, parent)
+        self.completion_popup = CompletionPopup(self)
+        self.request_completion = self.completion_doc_name = None
         self.gutter_width = 0
         self.tw = 2
         self.expected_geometry = expected_geometry
@@ -769,8 +772,21 @@ class TextEdit(PlainTextEdit):
             ev.setAccepted(False)
             return
         if self.smarts.handle_key_press(ev, self):
+            self.handle_keypress_completion(ev)
             return
         QPlainTextEdit.keyPressEvent(self, ev)
+        self.handle_keypress_completion(ev)
+
+    def handle_keypress_completion(self, ev):
+        if self.request_completion is None:
+            return
+        result = self.smarts.get_completion_data(self, ev)
+        if result is None:
+            return
+        self.request_completion(*result)
+
+    def handle_completion_result(self, result):
+        print (result)
 
     def replace_possible_unicode_sequence(self):
         c = self.textCursor()

src/calibre/gui2/tweak_book/editor/widget.py

@@ -173,6 +173,7 @@ class Editor(QMainWindow):
 
     def change_document_name(self, newname):
         self.editor.change_document_name(newname)
+        self.editor.completion_doc_name = newname
 
     def get_raw_data(self):
         # The EPUB spec requires NFC normalization, see section 1.3.6 of
@@ -220,6 +221,13 @@ class Editor(QMainWindow):
         tprefs['insert_tag_mru'] = mru
         self._build_insert_tag_button_menu()
 
+    def set_request_completion(self, callback=None, doc_name=None):
+        self.editor.request_completion = callback
+        self.editor.completion_doc_name = doc_name
+
+    def handle_completion_result(self, result):
+        return self.editor.handle_completion_result(result)
+
     def undo(self):
         self.editor.undo()
 
@@ -367,6 +375,7 @@ class Editor(QMainWindow):
         self.editor.smart_highlighting_updated.disconnect()
         self.editor.setPlainText('')
         self.editor.smarts = None
+        self.editor.request_completion = None
 
     def _modification_state_changed(self):
         self.is_synced_to_container = self.is_modified