From 50812974e0b9a0d319e7fbbfed3969b021ef8654 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 10 May 2014 20:53:29 +0530
Subject: [PATCH] Edit Book: Update the Table of Contents view automatically
 when the ncx file is edited.

Also avoid unnecessary rebuilds of the Table of Contents view.
---
 src/calibre/ebooks/oeb/polish/toc.py |  3 ++-
 src/calibre/gui2/tweak_book/boss.py  |  4 ++++
 src/calibre/gui2/tweak_book/toc.py   | 25 +++++++++++++++++++------
 src/calibre/gui2/tweak_book/ui.py    |  1 -
 4 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/src/calibre/ebooks/oeb/polish/toc.py b/src/calibre/ebooks/oeb/polish/toc.py
index 967c6cc34f..c614bd489b 100644
--- a/src/calibre/ebooks/oeb/polish/toc.py
+++ b/src/calibre/ebooks/oeb/polish/toc.py
@@ -186,9 +186,10 @@ def get_toc(container, verify_destinations=True):
     toc = find_existing_toc(container)
     if toc is None or not container.has_name(toc):
         ans = TOC()
-        ans.lang = ans.uid = None
+        ans.lang = ans.uid = ans.toc_file_name = None
         return ans
     ans = parse_ncx(container, toc)
+    ans.toc_file_name = toc
     if verify_destinations:
         verify_toc_destinations(container, ans)
     return ans
diff --git a/src/calibre/gui2/tweak_book/boss.py b/src/calibre/gui2/tweak_book/boss.py
index a73bea8ad0..578ec79e0b 100644
--- a/src/calibre/gui2/tweak_book/boss.py
+++ b/src/calibre/gui2/tweak_book/boss.py
@@ -1122,6 +1122,10 @@ class Boss(QObject):
 
     def editor_data_changed(self, editor):
         self.gui.preview.start_refresh_timer()
+        for name, ed in editors.iteritems():
+            if ed is editor:
+                self.gui.toc_view.start_refresh_timer(name)
+                break
 
     def editor_undo_redo_state_changed(self, *args):
         self.apply_current_editor_state()
diff --git a/src/calibre/gui2/tweak_book/toc.py b/src/calibre/gui2/tweak_book/toc.py
index 3c86e358a6..dcebcc6ec5 100644
--- a/src/calibre/gui2/tweak_book/toc.py
+++ b/src/calibre/gui2/tweak_book/toc.py
@@ -118,7 +118,6 @@ class TOCViewer(QWidget):
         self.setLayout(l)
         l.setContentsMargins(0, 0, 0, 0)
 
-        self.is_visible = False
         self.view = QTreeWidget(self)
         self.delegate = Delegate(self.view)
         self.view.setItemDelegate(self.delegate)
@@ -136,9 +135,22 @@ class TOCViewer(QWidget):
 
         self.refresh_action = QAction(QIcon(I('view-refresh.png')), _('&Refresh'), self)
         self.refresh_action.triggered.connect(self.refresh)
+        self.refresh_timer = t = QTimer(self)
+        t.setInterval(1000), t.setSingleShot(True)
+        t.timeout.connect(self.auto_refresh)
+        self.toc_name = None
+        self.currently_editing = None
+
+    def start_refresh_timer(self, name):
+        if self.isVisible() and self.toc_name == name:
+            self.refresh_timer.start()
+
+    def auto_refresh(self):
+        if self.isVisible():
+            self.refresh()
 
     def refresh(self):
-        self.refresh_requested.emit()  # Give boos a chance to commit dirty editors to the container
+        self.refresh_requested.emit()  # Give boss a chance to commit dirty editors to the container
         self.build()
 
     def item_pressed(self, item):
@@ -176,6 +188,7 @@ class TOCViewer(QWidget):
         if c is None:
             return
         toc = get_toc(c, verify_destinations=False)
+        self.toc_name = getattr(toc, 'toc_file_name', None)
 
         def process_node(toc, parent):
             for child in toc:
@@ -191,12 +204,12 @@ class TOCViewer(QWidget):
         self.view.clear()
         process_node(toc, self.view.invisibleRootItem())
 
-    def visibility_changed(self, visible):
-        self.is_visible = visible
-        if visible:
+    def showEvent(self, ev):
+        if self.toc_name is None or not ev.spontaneous():
             self.build()
+        return super(TOCViewer, self).showEvent(ev)
 
     def update_if_visible(self):
-        if self.is_visible:
+        if self.isVisible():
             self.build()
 
diff --git a/src/calibre/gui2/tweak_book/ui.py b/src/calibre/gui2/tweak_book/ui.py
index b4ac60f893..9570bbf95c 100644
--- a/src/calibre/gui2/tweak_book/ui.py
+++ b/src/calibre/gui2/tweak_book/ui.py
@@ -612,7 +612,6 @@ class Main(MainWindow):
         d.setWidget(self.toc_view)
         self.addDockWidget(Qt.LeftDockWidgetArea, d)
         d.close()  # Hidden by default
-        d.visibilityChanged.connect(self.toc_view.visibility_changed)
 
         d = create(_('Checkpoints'), 'checkpoints')
         d.setAllowedAreas(Qt.LeftDockWidgetArea | Qt.RightDockWidgetArea | Qt.BottomDockWidgetArea | Qt.TopDockWidgetArea)