startup: add a progress bar when cloning

Show a progress bar when cloning repositories so that the user knows
that the GUI is busy doing the clone.

Closes #312

Suggested-by: Raghavendra Karunanidhi <raghu.k@openly.co>
Signed-off-by: David Aguilar <davvid@gmail.com>

cola/cmds.py

@@ -807,18 +807,25 @@ def __init__(self, url, new_directory, spawn=True):
         self.new_directory = new_directory
         self.spawn = spawn
 
+        self.ok = False
+        self.error_message = ''
+        self.error_details = ''
+
     def do(self):
         status, out, err = self.model.git.clone(self.url, self.new_directory)
-        if status != 0:
-            Interaction.information(
-                    N_('Error: could not clone "%s"') % self.url,
+        self.ok = status == 0
+
+        if self.ok:
+            if self.spawn:
+                core.fork([sys.executable, sys.argv[0],
+                           '--repo', self.new_directory])
+        else:
+            self.error_message = N_('Error: could not clone "%s"') % self.url
+            self.error_details = (
                     (N_('git clone returned exit code %s') % status) +
-                    ((out+err) and ('\n\n' + out + err) or ''))
-            return False
-        if self.spawn:
-            core.fork([sys.executable, sys.argv[0],
-                       '--repo', self.new_directory])
-        return True
+                     ((out+err) and ('\n\n' + out + err) or ''))
+
+        return self
 
 
 class GitXBaseContext(object):

cola/guicmds.py

@@ -122,11 +122,11 @@ def open_new_repo():
     cmds.do(cmds.OpenRepo, dirname)
 
 
-def clone_repo(spawn=True):
+def prompt_for_clone():
     """
-    Present GUI controls for cloning a repository
+    Present a GUI for cloning a repository.
 
-    A new cola session is invoked when 'spawn' is True.
+    Returns the target directory and URL
 
     """
     url, ok = qtutils.prompt(N_('Path or URL to clone (Env. $VARS okay)'))
@@ -175,9 +175,8 @@ def clone_repo(spawn=True):
     while core.exists(destdir):
         destdir = olddestdir + str(count)
         count += 1
-    if cmds.do(cmds.Clone, url, destdir, spawn=spawn):
-        return destdir
-    return None
+
+    return url, destdir
 
 
 def export_patches():

cola/widgets/main.py

@@ -53,11 +53,14 @@
 from cola.widgets.log import LogWidget
 from cola.widgets.patch import apply_patches
 from cola.widgets.prefs import preferences
+from cola.widgets.progress import ProgressDialog
 from cola.widgets.recent import browse_recent_files
 from cola.widgets.status import StatusWidget
 from cola.widgets.search import search
 from cola.widgets.standard import MainWindow
 from cola.widgets.stash import stash
+from cola.widgets.tasks import TaskRunner
+from cola.widgets.tasks import CloneTask
 
 
 class MainView(MainWindow):
@@ -78,6 +81,11 @@ def __init__(self, model, parent=None, settings=None):
         # Keeps track of merge messages we've seen
         self.merge_message_hash = ''
 
+        # Runs asynchronous tasks
+        self.task_runner = TaskRunner(self)
+        self.clone_progress = ProgressDialog(N_('Clone Repository'),
+                                             N_('Cloning'), self)
+
         cfg = gitcfg.instance()
         self.browser_dockable = (cfg.get('cola.browserdockable') or
                                  cfg.get('cola.classicdockable'))
@@ -223,7 +231,7 @@ def __init__(self, model, parent=None, settings=None):
                 N_('Stash...'), stash, 'Alt+Shift+S')
 
         self.clone_repo_action = add_action(self,
-                N_('Clone...'), guicmds.clone_repo)
+                N_('Clone...'), self.clone_repo)
         self.clone_repo_action.setIcon(qtutils.git_icon())
 
         self.help_docs_action = add_action(self,
@@ -724,3 +732,26 @@ def rebase_skip(self):
 
     def rebase_abort(self):
         cmds.do(cmds.RebaseAbort)
+
+    def clone_repo(self):
+        result = guicmds.prompt_for_clone()
+        if result is None:
+            return
+        self.setEnabled(False)
+        self.clone_progress.setEnabled(True)
+        self.clone_progress.show()
+
+        # Use a thread to update in the background
+        url, destdir = result
+        task = CloneTask(self.task_runner, url, destdir, True)
+        self.task_runner.start(task, self.clone_task_done)
+
+    def clone_task_done(self, task):
+        """Continuation function called when the clone is complete"""
+        self.setEnabled(True)
+        self.clone_progress.hide()
+        if task.cmd is None:
+            return
+        if not task.cmd.ok:
+            Interaction.information(task.cmd.error_message,
+                                    task.cmd.error_details)

cola/widgets/startup.py

@@ -7,17 +7,23 @@
 """
 from __future__ import division, absolute_import, unicode_literals
 
+from PyQt4 import QtCore
 from PyQt4 import QtGui
 from PyQt4.QtCore import Qt
 from PyQt4.QtCore import SIGNAL
 
+from cola import cmds
 from cola import core
 from cola import guicmds
 from cola import qtutils
 from cola.compat import ustr
 from cola.i18n import N_
+from cola.interaction import Interaction
 from cola.settings import Settings
 from cola.widgets import defs
+from cola.widgets.progress import ProgressDialog
+from cola.widgets.tasks import TaskRunner
+from cola.widgets.tasks import CloneTask
 
 
 class StartupDialog(QtGui.QDialog):
@@ -28,6 +34,7 @@ def __init__(self, parent=None):
         self.setWindowTitle(N_('git-cola'))
 
         self.repodir = None
+        self.task_runner = TaskRunner(self)
 
         self.new_button = QtGui.QPushButton(N_('New...'))
         self.new_button.setIcon(qtutils.new_icon())
@@ -46,6 +53,13 @@ def __init__(self, parent=None):
         self.bookmarks_label = QtGui.QLabel(N_('Select Repository...'))
         self.bookmarks_label.setAlignment(Qt.AlignCenter)
 
+        # Gather widgets for easy enable/disable swapping
+        self.widgets = [
+                self.new_button,
+                self.open_button,
+                self.clone_button,
+                self.close_button,
+        ]
 
         self.bookmarks_model = QtGui.QStandardItemModel()
 
@@ -94,6 +108,8 @@ def __init__(self, parent=None):
         self.main_layout.addLayout(self.button_layout)
         self.setLayout(self.main_layout)
 
+        self.progress = ProgressDialog(N_('Clone Repository'),
+                                       N_('Cloning'), self)
 
         qtutils.connect_button(self.open_button, self.open_repo)
         qtutils.connect_button(self.clone_button, self.clone_repo)
@@ -129,10 +145,34 @@ def open_repo(self):
             self.accept()
 
     def clone_repo(self):
-        repodir = guicmds.clone_repo(spawn=False)
-        if repodir:
-            self.repodir = repodir
+        result = guicmds.prompt_for_clone()
+        if result is None:
+            return
+
+        for widget in self.widgets:
+            widget.setEnabled(False)
+
+        # Show a nice progress bar
+        self.progress.show()
+
+        # Use a thread to update in the background
+        url, destdir = result
+        task = CloneTask(self.task_runner, url, destdir, False)
+        self.task_runner.start(task, self.clone_task_done)
+
+    def clone_task_done(self, task):
+        for widget in self.widgets:
+            widget.setEnabled(True)
+        self.progress.hide()
+
+        if task.cmd is None:
+            return
+        if task.cmd.ok:
+            self.repodir = task.destdir
             self.accept()
+        else:
+            Interaction.information(task.cmd.error_message,
+                                    task.cmd.error_details)
 
     def new_repo(self):
         repodir = guicmds.new_repo()

cola/widgets/tasks.py

@@ -0,0 +1,65 @@
+from PyQt4 import QtCore
+from PyQt4.QtCore import SIGNAL
+
+from cola import cmds
+
+
+class TaskRunner(QtCore.QObject):
+    """Runs QRunnable instances and transfers control when they finish"""
+
+    def __init__(self, parent):
+        QtCore.QObject.__init__(self, parent)
+        self.tasks = []
+        self.task_callbacks = {}
+        self.connect(self, Task.FINISHED, self.finish)
+
+    def start(self, task, callback):
+        """Start the task and register a callback"""
+        self.tasks.append(task)
+        if callback is not None:
+            task_id = id(task)
+            self.task_callbacks[task_id] = callback
+        QtCore.QThreadPool.globalInstance().start(task)
+
+    def finish(self, task, *args, **kwargs):
+        task_id = id(task)
+        try:
+            self.tasks.remove(task)
+        except:
+            pass
+        try:
+            callback = self.task_callbacks[task_id]
+            del self.task_callbacks[task_id]
+        except KeyError:
+            return
+        callback(task, *args, **kwargs)
+
+
+class Task(QtCore.QRunnable):
+    """Base class for concrete tasks"""
+
+    FINISHED = SIGNAL('finished')
+
+    def __init__(self, sender):
+        QtCore.QRunnable.__init__(self)
+        self.sender = sender
+
+    def finish(self, *args, **kwargs):
+        self.sender.emit(self.FINISHED, self, *args, **kwargs)
+
+
+class CloneTask(Task):
+    """Clones a Git repository"""
+
+    def __init__(self, sender, url, destdir, spawn):
+        Task.__init__(self, sender)
+        self.url = url
+        self.destdir = destdir
+        self.spawn = spawn
+        self.cmd = None
+
+    def run(self):
+        """Runs the model action and captures the result"""
+        self.cmd = cmds.do(cmds.Clone, self.url, self.destdir,
+                           spawn=self.spawn)
+        self.finish()

share/doc/git-cola/relnotes.rst

@@ -9,6 +9,10 @@ Usability, bells and whistles
 
   https://github.com/git-cola/git-cola/issue/335
 
+* We now show a progress bar when cloning repositories.
+
+  https://github.com/git-cola/git-cola/issue/312
+
 git-cola v2.0.5
 ===============
 Usability, bells and whistles

share/doc/git-cola/thanks.rst

@@ -60,6 +60,7 @@ Thanks
 * Paolo G. Giarrusso
 * Paul Hildebrandt
 * Peter Júnoš
+* Raghavendra Karunanidhi
 * Rustam Safin
 * Samsul Ma'arif
 * Sergey Leschina