def __init__(self, directory=".", debug=False):
        """
            Initialisation method, setting the directory.

            :param directory:
                Root directory of the git repository.
        """
        QMainWindow.__init__(self)

        self._ui = Ui_MainWindow()
        self._ui.setupUi(self)

        self._modifications_shown = True
        self._directory = directory

        self.current_branch = None

        self._models = {}
        self.set_current_directory(directory)

        self.enable_modifications_buttons(False)

        self.filter_main_class = FilterMainClass(self, directory, self._models)
        self.rebase_main_class = RebaseMainClass(self, directory, self._models)

        self.reset_history()

        self._applying = False

        self.connect_slots()
class MainWindow(QMainWindow):
    """
        Main Window of gitbuster.
    """

    def __init__(self, directory=".", debug=False):
        """
            Initialisation method, setting the directory.

            :param directory:
                Root directory of the git repository.
        """
        QMainWindow.__init__(self)

        self._ui = Ui_MainWindow()
        self._ui.setupUi(self)

        self._modifications_shown = True
        self._directory = directory

        self.current_branch = None

        self._models = {}
        self.set_current_directory(directory)

        self.enable_modifications_buttons(False)

        self.filter_main_class = FilterMainClass(self, directory, self._models)
        self.rebase_main_class = RebaseMainClass(self, directory, self._models)

        self.reset_history()

        self._applying = False

        self.connect_slots()

    def create_new_branch_from_model(self, indexes, name=False):
        """
            This method creates a new branch from a given set of indexes.
            The first row of the index set will be used.
        """
        if not name:
            msgBox = BranchNameDialog(self)
            ret = msgBox.exec_()

            if ret:
                new_name = msgBox.get_new_name()
            else:
                return
        else:
            new_name = name

        from_model = indexes[0].model()

        selected_rows = set([index.row() for index in indexes])
        from_row = min(selected_rows)

        model = QEditableGitModel(self._models, directory=self._directory,
                                  fake_branch_name=new_name,
                                  from_model_row=(from_model, from_row),
                                  parent=self)
        model.populate()
        self.add_new_model(model)

        self.enable_modifications_buttons(True)

    def connect_slots(self):
        """
            Connect the slots to the objects.
        """
        gui = self._ui
        # Bottom bar connections
        _connect_button(gui.applyButton, self.apply)
        _connect_button(gui.refreshButton, self.refresh)

        # Connecting actions
        self.connect(gui.actionChange_repository,
                     SIGNAL("triggered(bool)"),
                     self.change_directory)

        action_shortcuts = (
            (gui.actionUndo, QKeySequence.Undo, self.undo_history),
            (gui.actionRedo, QKeySequence.Redo, self.redo_history),
            (gui.actionQuit, QKeySequence.Quit, self.quit),
            (gui.actionShow_modifications, None, self.show_modifications),
            (gui.actionHide_modifications, None, self.hide_modifications),
            (gui.actionNew_branch, None, self.new_remote_branch),
            (gui.actionApply, None, self.apply),
            (gui.actionAbout_Gitbuster, None, self.about_box))
        for action, shortcut, slot in action_shortcuts:
            if shortcut:
                action.setShortcut(shortcut)
            QObject.connect(action, SIGNAL("triggered()"), slot)

        self.connect(self.rebase_main_class, SIGNAL("newHistAction"),
                     self.add_history_action)
        self.connect(self.rebase_main_class, SIGNAL("newBranchFromCommit"),
                     self.create_new_branch_from_model)

        shortcut = QShortcut(QKeySequence(QKeySequence.Delete), self)
        QObject.connect(shortcut, SIGNAL("activated()"), self.remove_rows)

    def remove_rows(self):
        """
            Finds out which tab is activated, and forwards the command.
        """
        if self._ui.mainTabWidget.currentIndex() == 0:
            self.rebase_main_class.remove_rows()
        else:
            self.filter_main_class.remove_rows()

    def refresh(self, force=False):
        """
            This method is called when the refresh button is pressed.

            :param force:
                This allows test scripts not to have to deal with the
                QMessageBox.
        """
        if not force:
            msgBox = QMessageBox(self)
            msgBox.setText("You will lose all modifications.")
            msgBox.setInformativeText("Do you still want to refresh ?")
            msgBox.setStandardButtons(msgBox.Cancel | msgBox.Apply)
            msgBox.setDefaultButton(msgBox.Cancel)
            ret = (msgBox.exec_() == msgBox.Apply)
        else:
            ret = True

        if ret:
            self.set_current_directory(self._directory, reset_all=True)

    def about_box(self):
        """
            Displays an about box with information on Gitbuster.
        """
        title = "About Gitbuster v%s" % __version__
        text = "(c) 2010-2011 Julien Miotte <mike dot perdide at gmail dot " + \
               "com>\nWritten in Python, using PyQt4 and GitPython."
        QMessageBox.information(self, title, text, QMessageBox.Ok)

    def new_remote_branch(self):
        """
            Create a new branch.
            This can be a branch build with a directory repository or with an
            URL repository.
        """
        dialog = RemoteBranchDialog(self, self._directory)
        ret = dialog.exec_()

        if ret:
            new_remote = dialog.get_remote()
            new_model = QGitModel(self._directory, remote_ref=new_remote,
                                 parent=self)
            self.add_new_model(new_model)

    def add_new_model(self, model):
        """
            This adds the given model to the two tabs.
        """
        if not isinstance(model, QGitModel):
            model.setMerge(False)
        model.enable_option("filters")

        new_branch = model.get_current_branch() or model.get_remote_ref()
        self._models[new_branch] = model
        QObject.connect(model, SIGNAL("newHistoryEvent"),
                        self.new_history_event)

        self.filter_main_class.add_new_model(model)
        self.rebase_main_class.add_new_model(model)

    def remove_model(self, model):
        """
            This remove a previously displayed model.
        """
        self.filter_main_class.remove_model(model)
        self.rebase_main_class.remove_model(model)

    def reset_history(self):
        """
            Reset the history (for instance when the apply is finished
            successfully.
        """
        # This first history event is None, the history event for a given state
        # is given by self._history_state + 1
        self._history = [None, ]
        # The first state is 0
        self._history_state = 0

    def new_history_event(self):
        """
            When a history event occurs, we store the tab index, the displayed
            models and the model that was modified.
        """
        while self._history_state < len(self._history) - 1:
            self._history.pop()

        self._history_state += 1

        model = self.sender()
        activated_index = self._ui.mainTabWidget.currentIndex()
        if activated_index == 0:
            opened_model_index = self._ui.currentBranchComboBox.currentIndex()

            self._history.append([activated_index, opened_model_index,
                                  model, []])

        else:
            checkboxes = []
            for checkbox in self.rebase_main_class._checkboxes:
                if checkbox.isChecked():
                    checkboxes.append(checkbox)

            self._history.append([activated_index, checkboxes, model, []])

        self.enable_modifications_buttons(True)

    def enable_modifications_buttons(self, enable):
        """
            Hide or show the two modifications buttons.
        """
        self._ui.actionShow_modifications.setEnabled(enable)
        self._ui.actionHide_modifications.setEnabled(enable)

    def undo_history(self):
        """
            Reverts the history one event back, application wide.
        """
        if self._applying:
            return

        if self._history_state == 0:
            return

        model, actions = self.reproduce_conditions(self._history_state)
        model.undo_history()

        for action in actions:
            action.undo()

        self._history_state -= 1

        we_have_fake_models = [model for model in self._models.values()
                               if model.is_fake_model()]
        if self._history_state == 0 and not we_have_fake_models:
            self.enable_modifications_buttons(False)

    def redo_history(self):
        """
            Replays the history one event forward, application wide.
        """
        if self._applying:
            return

        if self._history_state == len(self._history) - 1:
            # If the current history state is the last one (as the first state
            # is None), we have an offset
            return

        model, actions = self.reproduce_conditions(self._history_state + 1)
        model.redo_history()

        for action in actions:
            action.redo()

        self._history_state += 1

        self.enable_modifications_buttons(True)

    def add_history_action(self, action):
        """
            Add special history actions (actions related to the GUI, not covered
            by the model history). For instance: setting the branch name in the
            name button.
        """
        self._history[self._history_state][3].append(action)

    def reproduce_conditions(self, history_state):
        """
            This method reproduces the settings of the application stored when
            the history event occured.

            :return:
                The model that was modified.
        """
        tab_index, index_or_checkboxes, model, actions = \
                                        self._history[history_state]

        self._ui.mainTabWidget.setCurrentIndex(tab_index)
        if tab_index == 0:
            self._ui.currentBranchComboBox.setCurrentIndex(index_or_checkboxes)
        else:
            for checkbox in self.rebase_main_class._checkboxes:
                if checkbox in index_or_checkboxes:
                    checkbox.setChecked(True)
                else:
                    checkbox.setChecked(False)

        return model, actions

    def set_current_directory(self, directory, reset_all=False):
        """
            Sets the current directory.

            :param directory:
                The git directory.
        """
        self._models = {}
        a_model = QGitModel(directory)
        self.current_branch = a_model.get_current_branch()

        for branch in a_model.get_branches():
            model = QEditableGitModel(self._models, directory=directory,
                                      parent=self)
            model.set_current_branch(branch)
            model.setMerge(False)
            model.enable_option("filters")
            model.populate()
            self._models[branch] = model

            QObject.connect(model, SIGNAL("newHistoryEvent"),
                            self.new_history_event)

        if reset_all:
            self.rebase_main_class.reset_interface(self._models)
            self.filter_main_class.reset_interface(self._models)

    def change_directory(self):
        """
            When the change directory action is triggered, pop up a dialog to
            select the new directory and set the directory of the model.
        """
        directory = select_git_directory()
        if directory:
            self.set_current_directory(directory, reset_all=True)

    def show_modifications(self):
        if not self._modifications_shown:
            self.toggle_modifications()

    def hide_modifications(self):
        if self._modifications_shown:
            self.toggle_modifications()

    def toggle_modifications(self):
        """
            When the toggleModifications button is pressed, change the displayed
            model.
        """
        self._modifications_shown = not self._modifications_shown

        self.filter_main_class.toggle_modifications(self._modifications_shown)
        self.rebase_main_class.toggle_modifications(self._modifications_shown)

    def apply(self):
        """
            Write the modifications to the git repository.
        """
        if self._applying:
            # Can't apply if we're already applying
            return

        self._applying = True

        def get_to_write_models():
            return [model for model in self._models.values()
                    if model.should_be_written()]

        to_write_models = run_long_operation("Counting modifications",
                                             get_to_write_models,
                                             parent=self)

        if to_write_models:
            msgBox = ConfirmDialog(to_write_models)
            ret = msgBox.exec_()

            if ret and msgBox.checked_models():
                log = msgBox.log_checked()
                force_committed_date = msgBox.force_checked()

                self.apply_models(msgBox.checked_models(), log,
                                  force_committed_date)

        self._applying = False

    def apply_models(self, models, log, force_committed_date):
        """
            Applies the given models.
        """
        write_results = {}

        self.apply_started()
        for model in models:
            def write_wait(log, force_committed_date, dont_populate=True):
                """
                    This is like write(), except we wait for the write to
                    finish.
                """
                model.write(log, force_committed_date, dont_populate)

                while not(model.is_finished_writing()):
                    time.sleep(1)

                return model.is_write_success()

            args = (log, force_committed_date)
            kwargs = {"dont_populate": True}
            result = run_long_operation("Applying %s" % model.name_to_display(),
                                        write_wait, args, kwargs,
                                        progress_method=model.progress,
                                        parent=self)

            write_results[model] = result

        self.apply_finished(write_results)

    def apply_started(self):
        """
            This method is called when the progress thread is started.
        """
        self._applying = True

    def apply_finished(self, write_results):
        """
            This method is called when the progress thread is finished.
        """
        self._applying = False
        self._ui.applyButton.setEnabled(True)

        a_repo = Repo(self._directory)

        for model, success in write_results.items():
            if success and model.is_fake_model():
                # If the applied models were fake, rebuild them.
                branch_name = model.name_to_display()
                new_branch = [branch for branch in a_repo.branches
                              if branch.name == branch_name][0]
                new_model = QEditableGitModel(self._models,
                                              directory=self._directory,
                                              parent=self)
                new_model.set_current_branch(new_branch)
                new_model.populate()
                self.remove_model(model)
                self.add_new_model(new_model)

            elif not success:
                if model.write_errors():
                    for error in model.write_errors():
                        print error
                else:
                    model.reset()
                    conflicting_index = model.get_conflicting_index()
                    self.rebase_main_class.commit_clicked(conflicting_index)
            elif success:
                model.populate()

        if True in write_results.values():
            # Reset history
            self.reset_history()

    def quit(self):
        """
            Display a message if gitbuster is in applying state and quit if the
            user still wants to.
        """
        ret = True
        if self._applying:
            msgBox = QMessageBox(self)
            msgBox.setText("Gitbuster is currently applying !")
            msgBox.setInformativeText("Do you still want to quit ?")
            msgBox.setStandardButtons(msgBox.Cancel | msgBox.Apply)
            msgBox.setDefaultButton(msgBox.Cancel)
            ret = (msgBox.exec_() == msgBox.Apply)

        if ret:
            self.close()

    def closeEvent(self, event):
        """
            Catching the close event to do some cleanup
        """
        def run_command(command):
            handle = Popen(command, shell=True, stdout=PIPE, stderr=PIPE)
            handle.wait()

        a_repo = Repo(self._directory)
        os.chdir(self._directory)

        try:
            active_branch_name = a_repo.active_branch.name
            should_be_cleaned = a_repo.active_branch.name == 'gitbuster_rebase'
        except TypeError:
            should_be_cleaned = True

        if should_be_cleaned:
            if a_repo.is_dirty():
                run_command("git reset --hard")

            fallback_branch_name = [branch.name for branch in a_repo.branches
                                    if branch.name != 'gitbuster_rebase'][0]
            run_command("git checkout %s" % fallback_branch_name)
            run_command("git branch -D gitbuster_rebase")