Start work on saving

src/calibre/gui2/tweak_book/boss.py

@@ -16,14 +16,16 @@ from calibre.ebooks.oeb.polish.main import SUPPORTED
 from calibre.ebooks.oeb.polish.container import get_container, clone_container
 from calibre.gui2.tweak_book import set_current_container, current_container, tprefs
 from calibre.gui2.tweak_book.undo import GlobalUndoHistory
+from calibre.gui2.tweak_book.save import SaveManager
 
 class Boss(QObject):
 
-    def __init__(self, parent=None):
+    def __init__(self, parent):
         QObject.__init__(self, parent)
         self.global_undo = GlobalUndoHistory()
         self.container_count = 0
         self.tdir = None
+        self.save_manager = SaveManager(parent)
 
     def __call__(self, gui):
         self.gui = gui
@@ -40,6 +42,7 @@ class Boss(QObject):
     def open_book(self, path=None):
         if not self.check_dirtied():
             return
+        # TODO: Check if a save is in progress and abort if it is
 
         if not hasattr(path, 'rpartition'):
             path = choose_files(self.gui, 'open-book-for-tweaking', _('Choose book'),
@@ -119,7 +122,10 @@ class Boss(QObject):
         # TODO: Update other GUI elements
 
     def save_book(self):
-        pass
+        self.gui.action_save.setEnabled(False)
+        tdir = tempfile.mkdtemp(prefix='save-%05d-' % self.container_count, dir=self.tdir)
+        container = clone_container(current_container(), tdir)
+        self.save_manager.schedule(tdir, container)
 
     def quit(self):
         if not self.confirm_quit():

src/calibre/gui2/tweak_book/save.py

@@ -0,0 +1,125 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+from __future__ import (unicode_literals, division, absolute_import,
+                        print_function)
+
+__license__ = 'GPL v3'
+__copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
+
+import shutil
+from threading import Thread
+from Queue import LifoQueue, Empty
+
+from PyQt4.Qt import (QObject, pyqtSignal, QLabel, QWidget, QHBoxLayout, Qt)
+
+from calibre.utils import join_with_timeout
+from calibre.gui2.progress_indicator import ProgressIndicator
+
+class SaveWidget(QWidget):
+
+    def __init__(self, parent=None):
+        QWidget.__init__(self, parent)
+        self.l = l = QHBoxLayout(self)
+        self.setLayout(l)
+        self.label = QLabel('')
+        self.pi = ProgressIndicator(self, 24)
+        l.addWidget(self.label)
+        l.addWidget(self.pi)
+        l.setContentsMargins(0, 0, 0, 0)
+        self.pi.setVisible(False)
+        self.stop()
+
+    def start(self):
+        self.pi.setVisible(True)
+        self.pi.startAnimation()
+        self.label.setText(_('Saving...'))
+
+    def stop(self):
+        self.pi.setVisible(False)
+        self.pi.stopAnimation()
+        self.label.setText(_('Saved'))
+
+class SaveManager(QObject):
+
+    start_save = pyqtSignal()
+    report_error = pyqtSignal(object)
+    save_done = pyqtSignal()
+
+    def __init__(self, parent):
+        QObject.__init__(self, parent)
+        self.count = 0
+        self.last_saved = -1
+        self.requests = LifoQueue()
+        t = Thread(name='save-thread', target=self.run)
+        t.daemon = True
+        t.start()
+        self.status_widget = w = SaveWidget(parent)
+        self.start_save.connect(w.start, type=Qt.QueuedConnection)
+        self.save_done.connect(w.stop, type=Qt.QueuedConnection)
+
+    def schedule(self, tdir, container):
+        self.count += 1
+        self.requests.put((self.count, tdir, container))
+
+    def run(self):
+        while True:
+            x = self.requests.get()
+            if x is None:
+                self.requests.task_done()
+                self.__empty_queue()
+                break
+            try:
+                count, tdir, container = x
+                self.process_save(count, tdir, container)
+            except:
+                import traceback
+                traceback.print_exc()
+            finally:
+                self.requests.task_done()
+
+    def __empty_queue(self):
+        ' Only to be used during shutdown '
+        while True:
+            try:
+                self.requests.get_nowait()
+            except Empty:
+                break
+            else:
+                self.requests.task_done()
+
+    def process_save(self, count, tdir, container):
+        if count <= self.last_saved:
+            shutil.rmtree(tdir, ignore_errors=True)
+            return
+        self.last_saved = count
+        self.start_save.emit()
+        try:
+            self.do_save(tdir, container)
+        except:
+            import traceback
+            self.report_error.emit(traceback.format_exc())
+        self.save_done.emit()
+
+    def do_save(self, tdir, container):
+        try:
+            import time
+            time.sleep(10)
+        finally:
+            shutil.rmtree(tdir, ignore_errors=True)
+
+    @property
+    def has_tasks(self):
+        return bool(self.requests.unfinished_tasks)
+
+    def wait(self, timeout=30):
+        if timeout is None:
+            self.requests.join()
+        else:
+            try:
+                join_with_timeout(self.requests, timeout)
+            except RuntimeError:
+                return False
+        return True
+
+    def shutdown(self):
+        self.requests.put(None)

src/calibre/gui2/tweak_book/ui.py

@@ -8,6 +8,7 @@ __copyright__ = '2013, Kovid Goyal <kovid at kovidgoyal.net>'
 
 from PyQt4.Qt import QDockWidget, Qt, QLabel, QIcon, QAction, QApplication
 
+from calibre.constants import __appname__, get_version
 from calibre.gui2.main_window import MainWindow
 from calibre.gui2.tweak_book import current_container, tprefs
 from calibre.gui2.tweak_book.file_list import FileListWidget
@@ -39,6 +40,11 @@ class Main(MainWindow):
 
         self.status_bar = self.statusBar()
         self.l = QLabel('Placeholder')
+        self.status_bar.addPermanentWidget(self.boss.save_manager.status_widget)
+        self.status_bar.addWidget(QLabel(_('%s %s created by %s') % (__appname__, get_version(), 'Kovid Goyal')))
+        f = self.status_bar.font()
+        f.setBold(True)
+        self.status_bar.setFont(f)
 
         self.setCentralWidget(self.l)
         self.boss(self)