Move the webengine part into a separate module for clarity

manual/creating_plugins.rst

@@ -266,6 +266,9 @@ The important part of the plugin is in two functions:
 .. literalinclude:: plugin_examples/webengine_demo/ui.py
     :lines: 47-
 
+.. literalinclude:: plugin_examples/webengine_demo/main.py
+    :lines: 12-
+
 
 The ``show_demo()`` function asks the user for a URL and then runs
 the ``main()`` function passing it that URL. The ``main()`` function

manual/plugin_examples/webengine_demo/main.py

@@ -1,154 +1,22 @@
 #!/usr/bin/env python2
-# vim:fileencoding=UTF-8:ts=4:sw=4:sta:et:sts=4:ai
+# vim:fileencoding=utf-8
+# License: GPL v3 Copyright: 2019, Kovid Goyal <kovid at kovidgoyal.net>
+
 from __future__ import absolute_import, division, print_function, unicode_literals
 
-__license__   = 'GPL v3'
+from PyQt5.Qt import QUrl
-__copyright__ = '2011, Kovid Goyal <kovid@kovidgoyal.net>'
+from PyQt5.QtWebEngineWidgets import QWebEngineView
-__docformat__ = 'restructuredtext en'
 
-if False:
+from calibre.gui2 import Application
-    # This is here to keep my python error checker from complaining about
-    # the builtin functions that will be defined by the plugin loading system
-    # You do not need this code in your plugins
-    get_icons = get_resources = None
-
-from PyQt5.Qt import QDialog, QVBoxLayout, QPushButton, QMessageBox, QLabel
-
-from calibre_plugins.interface_demo.config import prefs
 
 
-class DemoDialog(QDialog):
+def main(url):
-
+    # This function is run in a separate process and can do anything it likes,
-    def __init__(self, gui, icon, do_user_config):
+    # including use QWebEngine. Here it simply opens the passed in URL
-        QDialog.__init__(self, gui)
+    # in a QWebEngineView
-        self.gui = gui
+    app = Application([])
-        self.do_user_config = do_user_config
+    w = QWebEngineView()
-
+    w.setUrl(QUrl(url))
-        # The current database shown in the GUI
+    w.show()
-        # db is an instance of the class LibraryDatabase from db/legacy.py
+    w.raise_()
-        # This class has many, many methods that allow you to do a lot of
+    app.exec_()
-        # things. For most purposes you should use db.new_api, which has
-        # a much nicer interface from db/cache.py
-        self.db = gui.current_db
-
-        self.l = QVBoxLayout()
-        self.setLayout(self.l)
-
-        self.label = QLabel(prefs['hello_world_msg'])
-        self.l.addWidget(self.label)
-
-        self.setWindowTitle('Interface Plugin Demo')
-        self.setWindowIcon(icon)
-
-        self.about_button = QPushButton('About', self)
-        self.about_button.clicked.connect(self.about)
-        self.l.addWidget(self.about_button)
-
-        self.marked_button = QPushButton(
-            'Show books with only one format in the calibre GUI', self)
-        self.marked_button.clicked.connect(self.marked)
-        self.l.addWidget(self.marked_button)
-
-        self.view_button = QPushButton(
-            'View the most recently added book', self)
-        self.view_button.clicked.connect(self.view)
-        self.l.addWidget(self.view_button)
-
-        self.update_metadata_button = QPushButton(
-            'Update metadata in a book\'s files', self)
-        self.update_metadata_button.clicked.connect(self.update_metadata)
-        self.l.addWidget(self.update_metadata_button)
-
-        self.conf_button = QPushButton(
-                'Configure this plugin', self)
-        self.conf_button.clicked.connect(self.config)
-        self.l.addWidget(self.conf_button)
-
-        self.resize(self.sizeHint())
-
-    def about(self):
-        # Get the about text from a file inside the plugin zip file
-        # The get_resources function is a builtin function defined for all your
-        # plugin code. It loads files from the plugin zip file. It returns
-        # the bytes from the specified file.
-        #
-        # Note that if you are loading more than one file, for performance, you
-        # should pass a list of names to get_resources. In this case,
-        # get_resources will return a dictionary mapping names to bytes. Names that
-        # are not found in the zip file will not be in the returned dictionary.
-        text = get_resources('about.txt')
-        QMessageBox.about(self, 'About the Interface Plugin Demo',
-                text.decode('utf-8'))
-
-    def marked(self):
-        ''' Show books with only one format '''
-        db = self.db.new_api
-        matched_ids = {book_id for book_id in db.all_book_ids() if len(db.formats(book_id)) == 1}
-        # Mark the records with the matching ids
-        # new_api does not know anything about marked books, so we use the full
-        # db object
-        self.db.set_marked_ids(matched_ids)
-
-        # Tell the GUI to search for all marked records
-        self.gui.search.setEditText('marked:true')
-        self.gui.search.do_search()
-
-    def view(self):
-        ''' View the most recently added book '''
-        most_recent = most_recent_id = None
-        db = self.db.new_api
-        for book_id, timestamp in db.all_field_for('timestamp', db.all_book_ids()).items():
-            if most_recent is None or timestamp > most_recent:
-                most_recent = timestamp
-                most_recent_id = book_id
-
-        if most_recent_id is not None:
-            # Get a reference to the View plugin
-            view_plugin = self.gui.iactions['View']
-            # Ask the view plugin to launch the viewer for row_number
-            view_plugin._view_calibre_books([most_recent_id])
-
-    def update_metadata(self):
-        '''
-        Set the metadata in the files in the selected book's record to
-        match the current metadata in the database.
-        '''
-        from calibre.ebooks.metadata.meta import set_metadata
-        from calibre.gui2 import error_dialog, info_dialog
-
-        # Get currently selected books
-        rows = self.gui.library_view.selectionModel().selectedRows()
-        if not rows or len(rows) == 0:
-            return error_dialog(self.gui, 'Cannot update metadata',
-                             'No books selected', show=True)
-        # Map the rows to book ids
-        ids = list(map(self.gui.library_view.model().id, rows))
-        db = self.db.new_api
-        for book_id in ids:
-            # Get the current metadata for this book from the db
-            mi = db.get_metadata(book_id, get_cover=True, cover_as_data=True)
-            fmts = db.formats(book_id)
-            if not fmts:
-                continue
-            for fmt in fmts:
-                fmt = fmt.lower()
-                # Get a python file object for the format. This will be either
-                # an in memory file or a temporary on disk file
-                ffile = db.format(book_id, fmt, as_file=True)
-                ffile.seek(0)
-                # Set metadata in the format
-                set_metadata(ffile, mi, fmt)
-                ffile.seek(0)
-                # Now replace the file in the calibre library with the updated
-                # file. We dont use add_format_with_hooks as the hooks were
-                # already run when the file was first added to calibre.
-                db.add_format(book_id, fmt, ffile, run_hooks=False)
-
-        info_dialog(self, 'Updated files',
-                'Updated the metadata in the files of %d book(s)'%len(ids),
-                show=True)
-
-    def config(self):
-        self.do_user_config(parent=self)
-        # Apply the changes
-        self.label.setText(prefs['hello_world_msg'])

manual/plugin_examples/webengine_demo/ui.py

@@ -11,7 +11,7 @@ if False:
 
 # The class that all interface action plugins must inherit from
 from calibre.gui2.actions import InterfaceAction
-from PyQt5.Qt import QInputDialog, QUrl
+from PyQt5.Qt import QInputDialog
 
 
 class InterfacePlugin(InterfaceAction):
@@ -52,21 +52,4 @@ class InterfacePlugin(InterfaceAction):
             return
         # Launch a separate process to view the URL in WebEngine
         self.gui.job_manager.launch_gui_app('webengine-dialog', kwargs={
-            'module':'calibre_plugins.webengine_demo.ui', 'url':url})
+            'module':'calibre_plugins.webengine_demo.main', 'url':url})
-
-
-def main(url):
-    # This function is run in a separate process and can do anything it likes,
-    # including use QWebEngine. Here it simply opens the passed in URL
-    # in a QWebEngineView
-
-    # This import must happen before creating the Application() object
-    from PyQt5.QtWebEngineWidgets import QWebEngineView
-
-    from calibre.gui2 import Application
-    app = Application([])
-    w = QWebEngineView()
-    w.setUrl(QUrl(url))
-    w.show()
-    w.raise_()
-    app.exec_()