Live updates for the preview panel

src/calibre/ebooks/oeb/polish/container.py

@@ -368,6 +368,13 @@ class Container(object):  # {{{
             data = self.parse_css(data, self.relpath(path))
         return data
 
+    def raw_data(self, name, decode=True):
+        ans = self.open(name).read()
+        mime = self.mime_map.get(name, guess_type(name))
+        if decode and (mime in OEB_STYLES or mime in OEB_DOCS or mime[-4:] in {'+xml', '/xml'}):
+            ans = self.decode(ans)
+        return ans
+
     def parse_css(self, data, fname):
         from cssutils import CSSParser, log
         log.setLevel(logging.WARN)

src/calibre/gui2/tweak_book/__init__.py

@@ -13,6 +13,7 @@ tprefs.defaults['editor_theme'] = None
 tprefs.defaults['editor_font_family'] = None
 tprefs.defaults['editor_font_size'] = 12
 tprefs.defaults['editor_line_wrap'] = True
+tprefs.defaults['preview_refresh_time'] = 2
 
 _current_container = None
 

src/calibre/gui2/tweak_book/boss.py

@@ -24,6 +24,7 @@ from calibre.gui2.dialogs.confirm_delete import confirm
 from calibre.gui2.tweak_book import set_current_container, current_container, tprefs, actions, editors
 from calibre.gui2.tweak_book.undo import GlobalUndoHistory
 from calibre.gui2.tweak_book.save import SaveManager
+from calibre.gui2.tweak_book.preview import parse_worker
 from calibre.gui2.tweak_book.editor import editor_from_syntax, syntax_from_mime
 
 def get_container(*args, **kwargs):
@@ -232,6 +233,7 @@ class Boss(QObject):
         if editor is None:
             editor = editors[name] = editor_from_syntax(syntax, self.gui.editor_tabs)
             editor.undo_redo_state_changed.connect(self.editor_undo_redo_state_changed)
+            editor.data_changed.connect(self.editor_data_changed)
             c = current_container()
             with c.open(name) as f:
                 editor.data = c.decode(f.read())
@@ -260,6 +262,9 @@ class Boss(QObject):
         if ed is not None:
             ed.redo()
 
+    def editor_data_changed(self, editor):
+        self.gui.preview.refresh_timer.start(tprefs['preview_refresh_time'] * 1000)
+
     def editor_undo_redo_state_changed(self, *args):
         self.apply_current_editor_state(update_keymap=False)
 
@@ -280,7 +285,7 @@ class Boss(QObject):
                 if ed is x:
                     name = n
                     break
-            if name is not None:
+            if name is not None and getattr(ed, 'syntax', None) == 'html':
                 self.gui.preview.show(name)
         else:
             self.gui.keyboard.set_mode('other')
@@ -392,9 +397,10 @@ class Boss(QObject):
         QApplication.instance().quit()
 
     def shutdown(self):
+        self.gui.preview.refresh_timer.stop()
         self.save_state()
         self.save_manager.shutdown()
-        self.gui.preview.parse_worker.shutdown()
+        parse_worker.shutdown()
         self.save_manager.wait(0.1)
 
     def save_state(self):

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

@@ -16,6 +16,7 @@ class Editor(QMainWindow):
 
     modification_state_changed = pyqtSignal(object)
     undo_redo_state_changed = pyqtSignal(object, object)
+    data_changed = pyqtSignal(object)
 
     def __init__(self, syntax, parent=None):
         QMainWindow.__init__(self, parent)
@@ -30,6 +31,10 @@ class Editor(QMainWindow):
         self.redo_available = False
         self.editor.undoAvailable.connect(self._undo_available)
         self.editor.redoAvailable.connect(self._redo_available)
+        self.editor.textChanged.connect(self._data_changed)
+
+    def _data_changed(self):
+        self.data_changed.emit(self)
 
     def _undo_available(self, available):
         self.undo_available = available
@@ -50,6 +55,9 @@ class Editor(QMainWindow):
             self.editor.load_text(val, syntax=self.syntax)
         return property(fget=fget, fset=fset)
 
+    def get_raw_data(self):
+        return unicode(self.editor.toPlainText())
+
     def undo(self):
         self.editor.undo()
 
@@ -74,9 +82,11 @@ class Editor(QMainWindow):
     def break_cycles(self):
         self.modification_state_changed.disconnect()
         self.undo_redo_state_changed.disconnect()
+        self.data_changed.disconnect()
         self.editor.undoAvailable.disconnect()
         self.editor.redoAvailable.disconnect()
         self.editor.modificationChanged.disconnect()
+        self.editor.textChanged.disconnect()
         self.editor.setPlainText('')
 
 def launch_editor(path_to_edit, path_is_raw=False, syntax='html'):

src/calibre/gui2/tweak_book/preview.py

@@ -12,14 +12,14 @@ from Queue import Queue, Empty
 
 from PyQt4.Qt import (
     QWidget, QVBoxLayout, QApplication, QSize, QNetworkAccessManager,
-    QNetworkReply, QTimer, QNetworkRequest, QUrl)
+    QNetworkReply, QTimer, QNetworkRequest, QUrl, Qt, QNetworkDiskCache)
 from PyQt4.QtWebKit import QWebView
 
 from calibre import prints
 from calibre.constants import iswindows
 from calibre.ebooks.oeb.polish.parsing import parse
-from calibre.ebooks.oeb.base import serialize
-from calibre.gui2 import Dispatcher
+from calibre.ebooks.oeb.base import serialize, OEB_DOCS
+from calibre.ptempfile import PersistentTemporaryDirectory
 from calibre.gui2.tweak_book import current_container, editors
 from calibre.gui2.viewer.documentview import apply_settings
 from calibre.gui2.viewer.config import config
@@ -27,29 +27,43 @@ from calibre.utils.ipc.simple_worker import offload_worker
 
 shutdown = object()
 
+def get_data(name):
+    'Get the data for name. Returns a unicode string if name is a text document/stylesheet'
+    if name in editors:
+        return editors[name].get_raw_data()
+    return current_container().raw_data(name)
+
+# Parsing of html to add linenumbers {{{
 def parse_html(raw):
-    root = parse(raw, decoder=lambda x:x.decode('utf-8'), replace_entities=False, line_numbers=True, linenumber_attribute='lnum')
-    return serialize(root, 'text/html').decode('utf-8')
+    root = parse(raw, decoder=lambda x:x.decode('utf-8'), line_numbers=True, linenumber_attribute='lnum')
+    return serialize(root, 'text/html').encode('utf-8')
+
+class ParseItem(object):
+
+    __slots__ = ('name', 'length', 'fingerprint', 'parsed_data')
+
+    def __init__(self, name):
+        self.name = name
+        self.length, self.fingerprint = 0, None
+        self.parsed_data = None
 
 class ParseWorker(Thread):
 
     daemon = True
     SLEEP_TIME = 1
 
-    def __init__(self, callback=lambda x, y: None):
+    def __init__(self):
         Thread.__init__(self)
-        self.worker = offload_worker(priority='low')
         self.requests = Queue()
         self.request_count = 0
-        self.start()
-        self.cache = {}
-        self.callback = callback
+        self.parse_items = {}
 
     def run(self):
         mod, func = 'calibre.gui2.tweak_book.preview', 'parse_html'
         try:
             # Connect to the worker and send a dummy job to initialize it
-            self.worker(mod, func, b'<p></p>')
+            self.worker = offload_worker(priority='low')
+            self.worker(mod, func, '<p></p>')
         except:
             import traceback
             traceback.print_exc()
@@ -69,12 +83,7 @@ class ParseWorker(Thread):
                 break
             request = sorted(requests, reverse=True)[0]
             del requests
-            name, data = request[1:]
-            old_len, old_fp, old_parsed = self.cache.get(name, (None, None, None))
-            length, fp = len(data), hash(data)
-            if length == old_len and fp == old_fp:
-                self.done(name, old_parsed)
-                continue
+            pi, data = request[1:]
             try:
                 res = self.worker(mod, func, data)
             except:
@@ -86,45 +95,75 @@ class ParseWorker(Thread):
                     prints("Parser error:")
                     prints(res['tb'])
                 else:
-                    self.cache[name] = (length, fp, parsed_data)
-                    self.done(name, parsed_data)
-
-    def done(self, name, data):
-        try:
-            self.callback(name, data)
-        except Exception:
-            import traceback
-            traceback.print_exc()
+                    pi.parsed_data = parsed_data
 
     def add_request(self, name):
         data = get_data(name)
-        self.requests.put((self.request_count, name, data))
+        ldata, hdata = len(data), hash(data)
+        pi = self.parse_items.get(name, None)
+        if pi is None:
+            self.parse_items[name] = pi = ParseItem(name)
+        else:
+            if pi.length == ldata and pi.fingerprint == hdata:
+                return
+            pi.parsed_data = None
+        pi.length, pi.fingerprint = ldata, hdata
+        self.requests.put((self.request_count, pi, data))
         self.request_count += 1
 
     def shutdown(self):
         self.requests.put(shutdown)
 
+    def get_data(self, name):
+        return getattr(self.parse_items.get(name, None), 'parsed_data', None)
 
-class LocalNetworkReply(QNetworkReply):
+parse_worker = ParseWorker()
+# }}}
 
-    def __init__(self, parent, request, mime_type, data):
+# Override network access to load data "live" from the editors {{{
+class NetworkReply(QNetworkReply):
+
+    def __init__(self, parent, request, mime_type, name):
         QNetworkReply.__init__(self, parent)
         self.setOpenMode(QNetworkReply.ReadOnly | QNetworkReply.Unbuffered)
-        self.__data = data
         self.setRequest(request)
         self.setUrl(request.url())
-        self.setHeader(QNetworkRequest.ContentTypeHeader, mime_type)
+        self._aborted = False
+        if mime_type in OEB_DOCS:
+            self.resource_name = name
+            QTimer.singleShot(0, self.check_for_parse)
+        else:
+            data = get_data(name)
+            if isinstance(data, type('')):
+                data = data.encode('utf-8')
+                mime_type += '; charset=utf-8'
+            self.__data = data
+            self.setHeader(QNetworkRequest.ContentTypeHeader, mime_type)
+            self.setHeader(QNetworkRequest.ContentLengthHeader, len(self.__data))
+            QTimer.singleShot(0, self.finalize_reply)
+
+    def check_for_parse(self):
+        if self._aborted:
+            return
+        data = parse_worker.get_data(self.resource_name)
+        if data is None:
+            return QTimer.singleShot(10, self.check_for_parse)
+        self.__data = data
+        self.setHeader(QNetworkRequest.ContentTypeHeader, 'text/html; charset=utf-8')
         self.setHeader(QNetworkRequest.ContentLengthHeader, len(self.__data))
-        QTimer.singleShot(0, self.finalize_reply)
+        self.finalize_reply()
 
     def bytesAvailable(self):
-        return len(self.__data)
+        try:
+            return len(self.__data)
+        except AttributeError:
+            return 0
 
     def isSequential(self):
         return True
 
     def abort(self):
-        pass
+        self._aborted = True
 
     def readData(self, maxlen):
         ans, self.__data = self.__data[:maxlen], self.__data[maxlen:]
@@ -132,6 +171,8 @@ class LocalNetworkReply(QNetworkReply):
     read = readData
 
     def finalize_reply(self):
+        if self._aborted:
+            return
         self.setFinished(True)
         self.setAttribute(QNetworkRequest.HttpStatusCodeAttribute, 200)
         self.setAttribute(QNetworkRequest.HttpReasonPhraseAttribute, "Ok")
@@ -140,10 +181,6 @@ class LocalNetworkReply(QNetworkReply):
         self.readyRead.emit()
         self.finished.emit()
 
-def get_data(name):
-    if name in editors:
-        return editors[name].data
-    return current_container().open(name).read()
 
 class NetworkAccessManager(QNetworkAccessManager):
 
@@ -152,9 +189,16 @@ class NetworkAccessManager(QNetworkAccessManager):
                 'Custom')
     }
 
+    def __init__(self, *args):
+        QNetworkAccessManager.__init__(self, *args)
+        self.cache = QNetworkDiskCache(self)
+        self.setCache(self.cache)
+        self.cache.setCacheDirectory(PersistentTemporaryDirectory(prefix='disk_cache_'))
+        self.cache.setMaximumCacheSize(0)
+
     def createRequest(self, operation, request, data):
         url = unicode(request.url().toString())
-        if url.startswith('file://'):
+        if operation == self.GetOperation and url.startswith('file://'):
             path = url[7:]
             if iswindows and path.startswith('/'):
                 path = path[1:]
@@ -162,13 +206,13 @@ class NetworkAccessManager(QNetworkAccessManager):
             name = c.abspath_to_name(path)
             if c.has_name(name):
                 try:
-                    return LocalNetworkReply(self, request, c.mime_map.get(name, 'application/octet-stream'),
-                                             get_data(name) if operation == self.GetOperation else b'')
+                    return NetworkReply(self, request, c.mime_map.get(name, 'application/octet-stream'), name)
                 except Exception:
                     import traceback
-                    traceback.print_stack()
-        return QNetworkAccessManager.createRequest(self, operation, request,
-                data)
+                    traceback.print_exc()
+        return QNetworkAccessManager.createRequest(self, operation, request, data)
+
+# }}}
 
 class WebView(QWebView):
 
@@ -195,6 +239,20 @@ class WebView(QWebView):
     def sizeHint(self):
         return self._size_hint
 
+    def refresh(self):
+        self.pageAction(self.page().Reload).trigger()
+
+    @dynamic_property
+    def scroll_pos(self):
+        def fget(self):
+            mf = self.page().mainFrame()
+            return (mf.scrollBarValue(Qt.Horizontal), mf.scrollBarValue(Qt.Vertical))
+        def fset(self, val):
+            mf = self.page().mainFrame()
+            mf.setScrollBarValue(Qt.Horizontal, val[0])
+            mf.setScrollBarValue(Qt.Vertical, val[1])
+        return property(fget=fget, fset=fset)
+
 class Preview(QWidget):
 
     def __init__(self, parent=None):
@@ -202,21 +260,27 @@ class Preview(QWidget):
         self.l = l = QVBoxLayout()
         self.setLayout(l)
         l.setContentsMargins(0, 0, 0, 0)
-        self.parse_worker = ParseWorker(callback=Dispatcher(self.parsing_done))
         self.view = WebView(self)
         l.addWidget(self.view)
 
         self.current_name = None
-        self.parse_pending = False
         self.last_sync_request = None
+        self.refresh_timer = QTimer(self)
+        self.refresh_timer.timeout.connect(self.refresh)
+        parse_worker.start()
 
     def show(self, name):
-        self.current_name, self.parse_pending = name, True
-        self.parse_worker.add_request(name)
+        if name != self.current_name:
+            self.refresh_timer.stop()
+            self.current_name = name
+            parse_worker.add_request(name)
+            self.view.setUrl(QUrl.fromLocalFile(current_container().name_to_abspath(name)))
 
-    def parsing_done(self, name, data):
-        if name == self.current_name:
-            c = current_container()
-            self.view.setHtml(data, QUrl.fromLocalFile(c.name_to_abspath(name)))
-            self.parse_pending = False
+    def refresh(self):
+        if self.current_name:
+            # This will check if the current html has changed in its editor,
+            # and re-parse it if so
+            parse_worker.add_request(self.current_name)
+            # Tell webkit to reload all html and associated resources
+            self.view.refresh()