Refactor iframe communications client side code into a separate class

src/pyj/read_book/comm.pyj

@@ -2,9 +2,11 @@
 # License: GPL v3 Copyright: 2017, Kovid Goyal <kovid at kovidgoyal.net>
 from __python__ import bound_methods, hash_literals
 
+import traceback
 from aes import GCM
+from gettext import gettext as _, install
 
-from book_list.globals import main_js, get_translations
+from book_list.globals import get_translations, main_js
 from book_list.theme import get_font_family
 from dom import ensure_id
 
@@ -142,3 +144,63 @@ class IframeWrapper:
         self.encrypted_communications = True
         if callback:
             callback()
+
+
+class IframeClient:
+
+    def __init__(self, handlers):
+        self.encrypted_communications = False
+        self.handlers = {k: handlers[k] for k in handlers}
+        self.initialize_handler = handlers.initialize
+        self.handlers.initialize = self.initialize
+        self.ready_sent = False
+        window.addEventListener('message', self.handle_message, False)
+        window.addEventListener('load', def():
+            if not self.ready_sent:
+                self.send_message('ready', {})
+                self.ready_sent = True
+        )
+
+    def initialize(self, data):
+        nonlocal print
+        self.gcm_from_parent, self.gcm_to_parent = GCM(data.secret.subarray(0, 32)), GCM(data.secret.subarray(32))
+        if data.translations:
+            install(data.translations)
+        print = self.print_to_parent
+        self.encrypted_communications = True
+        if self.initialize_handler:
+            self.initialize_handler(data)
+
+    def print_to_parent(self, *args):
+        self.send_message('print', string=' '.join(map(str, args)))
+
+    def handle_message(self, event):
+        if event.source is not window.parent:
+            return
+        msg = event.data
+        data = msg.data
+        if msg.encrypted:
+            # We cannot use self.encrypted_communications as the 'display'
+            # message has to be unencrypted as it transports Blob objects
+            try:
+                data = JSON.parse(self.gcm_from_parent.decrypt(data))
+            except Exception as e:
+                print('Could not process message from parent:')
+                console.log(e)
+                return
+        func = self.handlers[data.action]
+        if func:
+            try:
+                func(data)
+            except Exception as e:
+                console.log('Error in iframe message handler:')
+                console.log(e)
+                self.send_message('error', title=_('Error in message handler'), details=traceback.format_exc(), msg=e.toString())
+        else:
+            print('Unknown action in message to iframe from parent: ' + data.action)
+
+    def send_message(self, action, data):
+        data.action = action
+        if self.encrypted_communications:
+            data = self.gcm_to_parent.encrypt(JSON.stringify(data))
+        window.parent.postMessage(data, '*')

src/pyj/read_book/content_popup.pyj

@@ -6,6 +6,7 @@ from elementmaker import E
 from gettext import gettext as _
 
 from dom import add_extra_css, build_rule, clear, svgicon
+from read_book.comm import IframeWrapper
 
 CLASS_NAME = 'book-content-popup-container'
 TOP_LEVEL_DISPLAY = 'flex'
@@ -38,15 +39,21 @@ class ContentPopupOverlay:
         self.view = view
         c = self.container
         c.classList.add(CLASS_NAME)
+        iframe = E.iframe(seamless=True, sandbox='allow-scripts')
 
         c.appendChild(E.div(
             E.div(),
-            E.iframe(seamless=True, sandbox='allow-scripts')
+            iframe
         ))
         c.addEventListener('click', self.hide)
         c.firstChild.addEventListener('click', def(ev):
             ev.stopPropagation(), ev.preventDefault()
         )
+        handlers = {
+            'ready': self.on_iframe_ready,
+        }
+        self.iframe_wrapper = IframeWrapper(handlers, iframe, 'popup', _('Loading data, please wait...'))
+        self.pending_load = None
 
     @property
     def container(self):
@@ -54,7 +61,7 @@ class ContentPopupOverlay:
 
     @property
     def iframe(self):
-        return self.container.querySelector('iframe')
+        return self.iframe_wrapper.iframe
 
     @property
     def is_visible(self):
@@ -67,6 +74,9 @@ class ContentPopupOverlay:
         c = self.container
         c.style.display = TOP_LEVEL_DISPLAY
 
+    def on_iframe_ready(self, msg):
+        return self.do_pending_load
+
     def apply_color_scheme(self, bg, fg):
         c = self.container.firstChild
         c.style.backgroundColor = bg

src/pyj/read_book/iframe.pyj

@@ -3,10 +3,10 @@
 from __python__ import bound_methods, hash_literals
 
 import traceback
-from aes import GCM
+from gettext import gettext as _
-from gettext import gettext as _, install
 
 from read_book.cfi import at_current, scroll_to as scroll_to_cfi
+from read_book.comm import IframeClient
 from read_book.flow_mode import (
     anchor_funcs as flow_anchor_funcs, flow_onkeydown, flow_onwheel,
     flow_to_scroll_fraction, handle_gesture as flow_handle_gesture,
@@ -66,7 +66,6 @@ class IframeBoss:
 
     def __init__(self):
         window.navigator.epubReadingSystem = EPUBReadingSystem()
-        self.ready_sent = False
         self.last_cfi = None
         self.replace_history_on_next_cfi_update = True
         self.encrypted_communications = False
@@ -74,14 +73,8 @@ class IframeBoss:
         self.resource_urls = {}
         self.content_ready = False
         self.last_window_width = self.last_window_height = -1
-        window.addEventListener('message', self.handle_message, False)
-        window.addEventListener('load', def():
-            if not self.ready_sent:
-                self.send_message('ready')
-                self.ready_sent = True
-        )
         set_boss(self)
-        self.handlers = {
+        handlers = {
             'initialize':self.initialize,
             'display': self.display,
             'scroll_to_anchor': self.on_scroll_to_anchor,
@@ -92,40 +85,12 @@ class IframeBoss:
             'find': self.find,
             'window_size': self.received_window_size,
         }
+        self.comm = IframeClient(handlers)
         self.last_window_ypos = 0
         self.length_before = None
 
-    def handle_message(self, event):
-        if event.source is not window.parent:
-            return
-        msg = event.data
-        data = msg.data
-        if msg.encrypted:
-            # We cannot use self.encrypted_communications as the 'display'
-            # message has to be unencrypted as it transports Blob objects
-            try:
-                data = JSON.parse(self.gcm_from_parent.decrypt(data))
-            except Exception as e:
-                print('Could not process message from parent:')
-                console.log(e)
-                return
-        func = self.handlers[data.action]
-        if func:
-            try:
-                func(data)
-            except Exception as e:
-                console.log('Error in iframe message handler:')
-                console.log(e)
-                self.send_message('error', title=_('Error in message handler'), details=traceback.format_exc(), msg=e.toString())
-        else:
-            print('Unknown action in message to iframe from parent: ' + data.action)
-
     def initialize(self, data):
-        nonlocal print
-        self.gcm_from_parent, self.gcm_to_parent = GCM(data.secret.subarray(0, 32)), GCM(data.secret.subarray(32))
         scroll_viewport.update_window_size(data.width, data.height)
-        if data.translations:
-            install(data.translations)
         window.onerror = self.onerror
         window.addEventListener('scroll', debounce(self.onscroll, 1000))
         window.addEventListener('resize', debounce(self.onresize, 500))
@@ -133,13 +98,8 @@ class IframeBoss:
         window.addEventListener('keydown', self.onkeydown)
         document.documentElement.addEventListener('contextmenu', self.oncontextmenu)
         self.color_scheme = data.color_scheme
-        self.encrypted_communications = True
-        print = self.print_to_parent
         create_touch_handlers()
 
-    def print_to_parent(self, *args):
-        self.send_message('print', string=' '.join(map(str, args)))
-
     def onerror(self, msg, script_url, line_number, column_number, error_object):
         if error_object is None:
             # This happens for cross-domain errors (probably javascript injected
@@ -365,10 +325,7 @@ class IframeBoss:
             self.send_message('show_chrome')
 
     def send_message(self, action, **data):
-        data.action = action
+        self.comm.send_message(action, data)
-        if self.encrypted_communications:
-            data = self.gcm_to_parent.encrypt(JSON.stringify(data))
-        window.parent.postMessage(data, '*')
 
     def connect_links(self):
         link_attr = 'data-' + self.book.manifest.link_uid
@@ -430,3 +387,5 @@ def init():
         script = document.getElementById('bootstrap')
         script.parentNode.removeChild(script)  # free up some memory
         IframeBoss()
+    # elif window.iframe_type is 'popup':
+    #     PopupIframeBoss()

src/pyj/read_book/view.pyj

@@ -325,6 +325,7 @@ class View:
         is_current_book = self.book and self.book.key == book.key
         if not is_current_book:
             self.iframe_wrapper.reset()
+            self.content_popup_overlay.iframe_wrapper.reset()
         self.book = current_book.book = book
         self.ui.db.update_last_read_time(book)
         self.loaded_resources = {}