Modernized progress window GUI

Following the refactoring that has been initiated in pdfmasher's
"vala" branch, I pushed more progress window logic into the
core.

The UI code is now a bit dumber than it used to be, and the core
now directly decides when the progress window is shown and
hidden. The "job finished" notification is also directly sent by the
core. Job description update logic is handled by a core gui
textfield.

Job description contsants also moved to the core, triggering
a localisation migration from "ui" to "core".

core/app.py

@@ -15,13 +15,16 @@ import time
 import shutil
 
 from send2trash import send2trash
+from jobprogress import job
 from hscommon.reg import RegistrableApplication
 from hscommon.notify import Broadcaster
 from hscommon.path import Path
 from hscommon.conflict import smart_move, smart_copy
+from hscommon.gui.progress_window import ProgressWindow
 from hscommon.util import (delete_if_empty, first, escape, nonone, format_time_decimal, allsame,
     rem_file_ext)
 from hscommon.trans import tr
+from hscommon.plat import ISWINDOWS
 
 from . import directories, results, scanner, export, fs
 from .gui.deletion_options import DeletionOptions
@@ -51,6 +54,16 @@ class JobType:
     Copy = 'job_copy'
     Delete = 'job_delete'
 
+JOBID2TITLE = {
+    JobType.Scan: tr("Scanning for duplicates"),
+    JobType.Load: tr("Loading"),
+    JobType.Move: tr("Moving"),
+    JobType.Copy: tr("Copying"),
+    JobType.Delete: tr("Sending to Trash"),
+}
+if ISWINDOWS:
+    JOBID2TITLE[JobType.Delete] = tr("Sending files to the recycle bin")
+
 def format_timestamp(t, delta):
     if delta:
         return format_time_decimal(t)
@@ -86,7 +99,6 @@ class DupeGuru(RegistrableApplication, Broadcaster):
     #--- View interface
     # open_path(path)
     # reveal_path(path)
-    # start_job(jobid, func, args=()) ( func(j, *args) )
     # ask_yes_no(prompt) --> bool
     # show_results_window()
     # show_problem_dialog()
@@ -123,6 +135,7 @@ class DupeGuru(RegistrableApplication, Broadcaster):
         self.stats_label = StatsLabel(self)
         self.result_table = self._create_result_table()
         self.deletion_options = DeletionOptions()
+        self.progress_window = ProgressWindow(self._job_completed)
         children = [self.result_table, self.directory_tree, self.stats_label, self.details_panel]
         for child in children:
             child.connect()
@@ -225,12 +238,16 @@ class DupeGuru(RegistrableApplication, Broadcaster):
             if self.results.get_group_of_duplicate(d) is not None]
         self.notify('results_changed')
     
-    def _job_completed(self, jobid, exc):
-        # Must be called by subclasses when they detect that an async job is completed. If an
-        # exception was raised during the job, `exc` will be set. Return True when the error was
-        # handled. If we return False when exc is set, a the exception will be re-raised.
-        if exc is not None:
-            return False # We don't handle any exception in here
+    def _start_job(self, jobid, func, args=()):
+        title = JOBID2TITLE[jobid]
+        try:
+            self.progress_window.run(jobid, title, func, args=args) 
+        except job.JobInProgressError:
+            msg = tr("A previous action is still hanging in there. You can't start a new one yet. Wait a few seconds, then try again.")
+            self.view.show_message(msg)
+    
+    def _job_completed(self, jobid):
+        print("complete!", jobid)
         if jobid == JobType.Scan:
             self._results_changed()
             if not self.results.groups:
@@ -362,7 +379,7 @@ class DupeGuru(RegistrableApplication, Broadcaster):
         if destination:
             desttype = self.options['copymove_dest_type']
             jobid = JobType.Copy if copy else JobType.Move
-            self.view.start_job(jobid, do)
+            self._start_job(jobid, do)
     
     def delete_marked(self):
         if not self._check_demo():
@@ -375,7 +392,7 @@ class DupeGuru(RegistrableApplication, Broadcaster):
         args = [self.deletion_options.link_deleted, self.deletion_options.use_hardlinks,
             self.deletion_options.direct]
         logging.debug("Starting deletion job with args %r", args)
-        self.view.start_job(JobType.Delete, self._do_delete, args=args)
+        self._start_job(JobType.Delete, self._do_delete, args=args)
     
     def export_to_xhtml(self):
         colnames, rows = self._get_export_data()
@@ -439,7 +456,8 @@ class DupeGuru(RegistrableApplication, Broadcaster):
     def load_from(self, filename):
         def do(j):
             self.results.load_from_xml(filename, self._get_file, j)
-        self.view.start_job(JobType.Load, do)
+            print("load finished")
+        self._start_job(JobType.Load, do)
     
     def make_selected_reference(self):
         dupes = self.without_ref(self.selected_dupes)
@@ -580,7 +598,7 @@ class DupeGuru(RegistrableApplication, Broadcaster):
             return
         self.results.groups = []
         self._results_changed()
-        self.view.start_job(JobType.Scan, do)
+        self._start_job(JobType.Scan, do)
     
     def toggle_selected_mark_state(self):
         selected = self.without_ref(self.selected_dupes)