Save to disk: Show some feedback while in the collecting data phase

src/calibre/gui2/add.py

@@ -451,7 +451,8 @@ class Saver(QObject): # {{{
         self.callback_called = False
         self.rq = Queue()
         self.ids = [x for x in map(db.id, [r.row() for r in rows]) if x is not None]
-        self.pd.set_max(len(self.ids))
+        self.pd_max = len(self.ids)
+        self.pd.set_max(0)
         self.pd.value = 0
         self.failures = set([])
 
@@ -510,6 +511,8 @@ class Saver(QObject): # {{{
             id, title, ok, tb = self.rq.get_nowait()
         except Empty:
             return
+        if self.pd.max != self.pd_max:
+            self.pd.max = self.pd_max
         self.pd.value += 1
         self.ids.remove(id)
         if not isinstance(title, unicode):

src/calibre/gui2/dialogs/progress.py

@@ -53,6 +53,13 @@ class ProgressDialog(QDialog, Ui_Dialog):
     def set_max(self, max):
         self.bar.setMaximum(max)
 
+    @dynamic_property
+    def max(self):
+        def fget(self): return self.bar.maximum()
+        def fset(self, val): self.bar.setMaximum(val)
+        return property(fget=fget, fset=fset)
+
+
     def _canceled(self, *args):
         self.canceled = True
         self.button_box.setDisabled(True)