Downgrade

CHANGELOG.md

@@ -6,13 +6,14 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [0.3.0]
 ### Features
-- Allows app uninstall by right clicking it.
+- Allows app uninstall and downgrade by right clicking it.
 
 ### Improvements
 - Adding tooltips to toolbar buttons
 - "Update ?" column renamed to "Upgrade ?"
 - Management panel title renamed
 - Showing runtime apps when no app is available
+- Allowing to specify a custom app translation with the environment variable FPAKMAN_LOCALE
 
 ## [0.2.1] - 2019-06-24
 ### Features

README.md

@@ -42,6 +42,7 @@ In order to autostart the application, use your Desktop Environment settings to
 You can change some application settings via environment variables:
 - **FPAKMAN_UPDATE_NOTIFICATION**: enable or disable system updates notifications. Use **0** (disable) or **1** (enable, default).
 - **FPAKMAN_CHECK_INTERVAL**: define the updates check interval in seconds. Default: 60.
+- **FPAKMAN_LOCALE**: define a custom app translation for a given locale key (e.g: 'pt', 'en', 'es', ...). Default: system locale.
 
 ### Roadmap
 - Search and install applications

fpakman/app.py

@@ -16,7 +16,7 @@ parser = argparse.ArgumentParser(prog='fpakman', description="GUI for Flatpak ap
 parser.add_argument('-v', '--version', action='version', version='%(prog)s {}'.format(__version__))
 args = parser.parse_args()
 
-locale_keys = util.get_locale_keys()
+locale_keys = util.get_locale_keys(os.getenv('FPAKMAN_LOCALE', None))
 
 app = QApplication(sys.argv)
 app.setWindowIcon(QIcon(resource.get_path('img/flathub_45.svg')))
@@ -26,6 +26,7 @@ controller = FlatpakController(manager)
 
 trayIcon = TrayIcon(locale_keys=locale_keys,
                     controller=controller,
+                    manager=manager,
                     check_interval=int(os.getenv('FPAKMAN_CHECK_INTERVAL', 60)))
 trayIcon.show()
 

fpakman/core/flatpak.py

@@ -1,4 +1,5 @@
 import re
+import subprocess
 from typing import List
 
 from fpakman.core import system
@@ -32,20 +33,33 @@ def app_str_to_json(line: str, version: str) -> dict:
     else:
         raise Exception('Unsupported version')
 
-    info = re.findall(r'\w+:\s.+', get_app_info(app['id'], app['branch']))
+    extra_fields = get_app_info_fields(app['id'], app['branch'], ['origin', 'arch', 'ref', 'commit'], check_runtime=True)
-    fields_to_get = ['origin', 'arch', 'ref']
+    app.update(extra_fields)
+
+    return app
+
+
+def get_app_info_fields(app_id: str, branch: str, fields: List[str], check_runtime: bool = False):
+    info = re.findall(r'\w+:\s.+', get_app_info(app_id, branch))
+    data = {}
+    fields_to_retrieve = len(fields) + (1 if check_runtime and 'ref' not in fields else 0)
 
     for field in info:
+
+        if fields_to_retrieve == 0:
+            break
+
         field_val = field.split(':')
         field_name = field_val[0].lower()
 
-        if field_name in fields_to_get:
+        if field_name in fields or (check_runtime and field_name == 'ref'):
-            app[field_name] = field_val[1].strip()
+            data[field_name] = field_val[1].strip()
+            fields_to_retrieve -= 1
 
-        if field_name == 'ref':
+        if check_runtime and field_name == 'ref':
-            app['runtime'] = app['ref'].startswith('runtime/')
+            data['runtime'] = data['ref'].startswith('runtime/')
 
-    return app
+    return data
 
 
 def get_version():
@@ -92,3 +106,20 @@ def uninstall_and_stream(app_ref: str):
 
 def list_updates_as_str():
     return system.run_cmd('flatpak update', ignore_return_code=True)
+
+
+def downgrade_and_stream(app_ref: str, commit: str, root_password: str):
+
+    pwdin, downgrade_cmd = None, []
+
+    if root_password is not None:
+        downgrade_cmd.extend(['sudo', '-S'])
+        pwdin = subprocess.Popen(['echo', root_password], stdout=subprocess.PIPE).stdout
+
+    downgrade_cmd.extend(['flatpak', 'update', '--commit={}'.format(commit), app_ref, '-y'])
+    return subprocess.Popen(downgrade_cmd, stdin=pwdin, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL).stdout
+
+
+def get_app_commits(app_ref: str, origin: str) -> List[str]:
+    log = system.run_cmd('flatpak remote-info --log {} {}'.format(origin, app_ref))
+    return re.findall(r'Commit+:\s(.+)', log)

fpakman/core/model.py

@@ -2,9 +2,6 @@ from threading import Lock, Thread
 from typing import List
 
 import requests
-from PyQt5.QtCore import QUrl
-from PyQt5.QtGui import QPixmap, QIcon
-from PyQt5.QtNetwork import QNetworkAccessManager, QNetworkRequest
 
 from fpakman.core import flatpak
 
@@ -12,6 +9,10 @@ __FLATHUB_URL__ = 'https://flathub.org'
 __FLATHUB_API_URL__ = __FLATHUB_URL__ + '/api/v1'
 
 
+class ImpossibleDowngradeException(Exception):
+    pass
+
+
 class FlatpakManager:
 
     def __init__(self):
@@ -122,3 +123,20 @@ class FlatpakManager:
 
             if app_found:
                 return flatpak.uninstall_and_stream(ref)
+
+    def downgrade_app(self, ref: str, root_password: str):
+
+        if self.apps:
+
+            app_found = self._find_by_ref(ref)
+
+            if app_found:
+                commits = flatpak.get_app_commits(app_found['ref'], app_found['origin'])
+
+                commit_idx = commits.index(app_found['commit'])
+
+                # downgrade is not possible if the app current commit in the first one:
+                if commit_idx == len(commits) - 1:
+                    raise ImpossibleDowngradeException()
+
+                return flatpak.downgrade_and_stream(app_found['ref'], commits[commit_idx + 1], root_password)

fpakman/core/util.py

@@ -4,11 +4,15 @@ from fpakman.core import resource
 import glob
 
 
-def get_locale_keys():
+def get_locale_keys(key: str = None):
 
-    current_locale = locale.getdefaultlocale()
     locale_path = None
 
+    if key is None:
+        current_locale = locale.getdefaultlocale()
+    else:
+        current_locale = [key]
+
     if current_locale:
         current_locale = current_locale[0]
 

fpakman/resources/img/downgrade.svg

@@ -0,0 +1,72 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   version="1.1"
+   viewBox="0 0 48 48"
+   enable-background="new 0 0 26 26"
+   id="svg8"
+   sodipodi:docname="downgrade.svg"
+   inkscape:version="0.92.3 (2405546, 2018-03-11)"
+   width="48"
+   height="48">
+  <metadata
+     id="metadata14">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title></dc:title>
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs12" />
+  <sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="1366"
+     inkscape:window-height="739"
+     id="namedview10"
+     showgrid="false"
+     showborder="false"
+     inkscape:zoom="9.0769231"
+     inkscape:cx="-0.33050843"
+     inkscape:cy="20.813559"
+     inkscape:window-x="0"
+     inkscape:window-y="260"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="svg8"
+     fit-margin-top="0"
+     fit-margin-left="0"
+     fit-margin-right="0"
+     fit-margin-bottom="0" />
+  <g
+     id="g6"
+     transform="matrix(1.8461538,0,0,2,0,-2)"
+     style="fill:#ff0000">
+    <path
+       d="m 25,17 h -2 c -0.6,0 -1,0.4 -1,1 v 2.5 C 22,20.8 21.8,21 21.5,21 H 4.5 C 4.2,21 4,20.8 4,20.5 V 18 C 4,17.4 3.6,17 3,17 H 1 c -0.6,0 -1,0.4 -1,1 v 6 c 0,0.6 0.4,1 1,1 h 24 c 0.6,0 1,-0.4 1,-1 v -6 c 0,-0.6 -0.4,-1 -1,-1 z"
+       id="path2"
+       inkscape:connector-curvature="0"
+       style="fill:#ff0000" />
+    <path
+       d="m 12.3,16.7 c 0.2,0.2 0.5,0.3 0.7,0.3 0.2,0 0.5,-0.1 0.7,-0.3 l 6,-6 C 19.9,10.5 20,10.3 20,10 20,9.7 19.9,9.5 19.7,9.3 L 18.3,7.9 C 18.1,7.7 17.9,7.6 17.6,7.6 c -0.3,0 -0.5,0.1 -0.7,0.3 l -1,1 C 15.6,9.2 15,9 15,8.5 V 2 C 15,1.4 14.6,1 14,1 H 12 C 11.4,1 11,1.4 11,2 V 8.6 C 11,9 10.5,9.3 10.1,9 L 9.1,8 C 8.9,7.8 8.7,7.7 8.4,7.7 8.1,7.7 7.9,7.8 7.7,8 L 6.3,9.4 C 6.1,9.6 6,9.8 6,10.1 c 0,0.3 0.1,0.5 0.3,0.7 z"
+       id="path4"
+       inkscape:connector-curvature="0"
+       style="fill:#ff0000" />
+  </g>
+</svg>

fpakman/resources/locale/en

@@ -10,15 +10,27 @@ manage_window.columns.update=Upgrade ?
 manage_window.apps_table.row.actions.uninstall=Uninstall
 manage_window.apps_table.row.actions.uninstall.popup.title=Uninstall
 manage_window.apps_table.row.actions.uninstall.popup.body=Remove {} ?
+manage_window.apps_table.row.actions.downgrade=Downgrade
+manage_window.apps_table.row.actions.downgrade.popup.body=Do you really want to downgrade {} ?
 manage_window.checkbox.only_apps=Apps
 manage_window.label.updates=Updates
 manage_window.status.refreshing=Refreshing
 manage_window.status.upgrading=Upgrading
 manage_window.status.uninstalling=Uninstalling
+manage_window.status.downgrading=Downgrading
 manage_window.bt.refresh.tooltip=Reload the data about installed applications
 manage_window.bt.upgrade.tooltip=Upgrade all selected applications
 popup.flatpak_not_installed.title=Error
 popup.flatpak_not_installed.msg=flatpak seems not to be installed. Exiting
+popup.root.title=Requires root privileges
+popup.root.password=Password
+popup.root.bad_password.title=Error
+popup.root.bad_password.body=Wrong password
+popup.downgrade.impossible.title=Impossible to downgrade
+popup.downgrade.impossible.body=The app is in its first version
+popup.button.yes=Yes
+popup.button.no=No
+popup.button.cancel=Cancel
 tray.action.manage=Manage applications
 tray.action.exit=Exit
 notification.new_updates=Updates found

fpakman/resources/locale/es

@@ -2,7 +2,7 @@ manage_window.title=Administrador de Aplicativos Flatpak
 manage_window.columns.name=Nombre
 manage_window.columns.version=Versión
 manage_window.columns.latest_version=Ultima Versión
-manage_window.columns.branch=Branch
+manage_window.columns.branch=Rama
 manage_window.columns.arch=Arch
 manage_window.columns.ref=Ref
 manage_window.columns.origin=Origen
@@ -10,15 +10,27 @@ manage_window.columns.update=¿Actualizar?
 manage_window.apps_table.row.actions.uninstall=Desinstalar
 manage_window.apps_table.row.actions.uninstall.popup.title=Desinstalación
 manage_window.apps_table.row.actions.uninstall.popup.body=¿Eliminar {}?
+manage_window.apps_table.row.actions.downgrade=Revertir versión
+manage_window.apps_table.row.actions.downgrade.popup.body=¿Realmente quieres revertir la versión actual de {}?
 manage_window.checkbox.only_apps=Apps
 manage_window.label.updates=Actualizaciones
 manage_window.status.refreshing=Recargando
 manage_window.status.upgrading=Actualizando
 manage_window.status.uninstalling=Desinstalando
+manage_window.status.downgrading=Revirtiendo
 manage_window.bt.refresh.tooltip=Recarga los datos sobre los aplicativos instalados
 manage_window.bt.upgrade.tooltip=Actualiza todos los aplicativos seleccionados
 popup.flatpak_not_installed.title=Error
 popup.flatpak_not_installed.msg=flatpak no parece estar instalado. Saliendo
+popup.root.title=Requiere privilegios de root
+popup.root.password=Contraseña
+popup.root.bad_password.title=Error
+popup.root.bad_password.body=Contraseña incorrecta
+popup.downgrade.impossible.title=Imposible revertir la versión
+popup.downgrade.impossible.body=El aplicativo está en su primera versión
+popup.button.yes=Sí
+popup.button.no=No
+popup.button.cancel=Cancelar
 tray.action.manage=Administrar aplicativos
 tray.action.exit=Salir
 notification.new_updates=Actualizaciones encontradas

fpakman/resources/locale/pt

@@ -10,15 +10,27 @@ manage_window.columns.update=Atualizar ?
 manage_window.apps_table.row.actions.uninstall=Desinstalar
 manage_window.apps_table.row.actions.uninstall.popup.title=Desinstalação
 manage_window.apps_table.row.actions.uninstall.popup.body=Remover {}?
+manage_window.apps_table.row.actions.downgrade=Reverter versão
+manage_window.apps_table.row.actions.downgrade.popup.body=Você realmente quer reverter a versão atual de {} ?
 manage_window.checkbox.only_apps=Apps
 manage_window.label.updates=Atualizações
 manage_window.status.refreshing=Recarregando
 manage_window.status.upgrading=Atualizando
 manage_window.status.uninstalling=Desinstalando
+manage_window.status.downgrading=Revertendo
 manage_window.bt.refresh.tooltip=Recarrega os dados sobre os aplicativos instalados
 manage_window.bt.upgrade.tooltip=Atualiza todos os aplicativos selecionados
 popup.flatpak_not_installed.title=Erro
 popup.flatpak_not_installed.msg=flatpak não parece estar instalado. Saindo
+popup.root.title=Requer privilégios de root
+popup.root.password=Senha
+popup.root.bad_password.title=Erro
+popup.root.bad_password.body=Senha incorreta
+popup.downgrade.impossible.title=Impossível reverter a versão
+popup.downgrade.impossible.body=O aplicativo está na sua primeira versão
+popup.button.yes=Sim
+popup.button.no=Não
+popup.button.cancel=Cancelar
 tray.action.manage=Gerenciar aplicativos
 tray.action.exit=Sair
 notification.new_updates=Atualizações encontradas

fpakman/view/qt/apps_table.py

@@ -8,6 +8,7 @@ from PyQt5.QtWidgets import QTableWidget, QTableView, QMenu, QAction, QTableWidg
 
 from fpakman.core import resource
 from fpakman.core.controller import FlatpakController
+from fpakman.view.qt import dialog
 
 
 class UpdateToggleButton(QToolButton):
@@ -48,6 +49,7 @@ class AppsTable(QTableWidget):
         self.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
         self.icon_flathub = QIcon(resource.get_path('img/flathub_45.svg'))
         self.icon_uninstall = QIcon(resource.get_path('img/uninstall.svg'))
+        self.icon_downgrade = QIcon(resource.get_path('img/downgrade.svg'))
 
         self.network_man = QNetworkAccessManager()
         self.network_man.finished.connect(self._load_icon)
@@ -60,21 +62,39 @@ class AppsTable(QTableWidget):
         action_uninstall = QAction(self.parent.locale_keys["manage_window.apps_table.row.actions.uninstall"])
         action_uninstall.setIcon(self.icon_uninstall)
         action_uninstall.triggered.connect(self._uninstall_app)
-
         menu_row.addAction(action_uninstall)
+
+        app = self._get_selected_app()
+
+        if not app['model']['runtime']:  # downgrade only allowed for apps
+            action_downgrade = QAction(self.parent.locale_keys["manage_window.apps_table.row.actions.downgrade"])
+            action_downgrade.triggered.connect(self._downgrade_app)
+            action_downgrade.setIcon(self.icon_downgrade)
+            menu_row.addAction(action_downgrade)
+
         menu_row.adjustSize()
         menu_row.popup(QCursor.pos())
         menu_row.exec_()
 
-    def _uninstall_app(self):
+    def _get_selected_app(self):
-        selected_app = self.parent.apps[self.currentRow()]
+        return self.parent.apps[self.currentRow()]
 
-        confirmation = QMessageBox.question(self, self.parent.locale_keys['manage_window.apps_table.row.actions.uninstall.popup.title'],
+    def _uninstall_app(self):
-                                            self.parent.locale_keys['manage_window.apps_table.row.actions.uninstall.popup.body'].format(selected_app['model']['name']),
+        selected_app = self._get_selected_app()
-                                            QMessageBox.Yes | QMessageBox.No, QMessageBox.No)
+
-        if confirmation == QMessageBox.Yes:
+        if dialog.ask_confirmation(title=self.parent.locale_keys['manage_window.apps_table.row.actions.uninstall.popup.title'],
+                                   body=self.parent.locale_keys['manage_window.apps_table.row.actions.uninstall.popup.body'].format(selected_app['model']['name']),
+                                   locale_keys=self.parent.locale_keys):
             self.parent.uninstall_app(selected_app['model']['ref'])
 
+    def _downgrade_app(self):
+        selected_app = self._get_selected_app()
+
+        if dialog.ask_confirmation(title=self.parent.locale_keys['manage_window.apps_table.row.actions.downgrade'],
+                                   body=self.parent.locale_keys['manage_window.apps_table.row.actions.downgrade.popup.body'].format(selected_app['model']['name']),
+                                   locale_keys=self.parent.locale_keys):
+            self.parent.downgrade_app(selected_app['model']['ref'])
+
     def _load_icon(self, http_response):
         icon_url = http_response.url().toString()
         pixmap = QPixmap()
@@ -122,7 +142,7 @@ class AppsTable(QTableWidget):
                 col_release.setFlags(Qt.ItemIsSelectable | Qt.ItemIsEnabled)
                 self.setItem(idx, 2, col_release)
 
-                if app['model']['update']:
+                if app['model']['version'] and app['model']['latest_version'] and app['model']['version'] < app['model']['latest_version']:
                     col_release.setForeground(QColor('orange'))
 
                 col_branch = QTableWidgetItem()

fpakman/view/qt/dialog.py

@@ -0,0 +1,31 @@
+from PyQt5.QtGui import QIcon
+from PyQt5.QtWidgets import QMessageBox
+
+from fpakman.core import resource
+
+
+def show_error(title: str, body: str, icon: QIcon = QIcon(resource.get_path('img/flathub_45.svg'))):
+    error_msg = QMessageBox()
+    error_msg.setIcon(QMessageBox.Critical)
+    error_msg.setWindowTitle(title)
+    error_msg.setText(body)
+
+    if icon:
+        error_msg.setWindowIcon(icon)
+    error_msg.exec_()
+
+
+def ask_confirmation(title: str, body: str, locale_keys: dict, icon: QIcon = QIcon(resource.get_path('img/flathub_45.svg'))):
+    dialog_confirmation = QMessageBox()
+    dialog_confirmation.setIcon(QMessageBox.Critical)
+    dialog_confirmation.setWindowTitle(title)
+    dialog_confirmation.setText(body)
+    bt_yes = dialog_confirmation.addButton(locale_keys['popup.button.yes'], QMessageBox.YesRole)
+    dialog_confirmation.addButton(locale_keys['popup.button.no'], QMessageBox.NoRole)
+
+    if icon:
+        dialog_confirmation.setWindowIcon(icon)
+
+    dialog_confirmation.exec_()
+
+    return dialog_confirmation.clickedButton() == bt_yes

fpakman/view/qt/root.py

@@ -0,0 +1,39 @@
+import os
+import subprocess
+
+from PyQt5.QtWidgets import QInputDialog, QLineEdit
+
+from fpakman.view.qt.dialog import show_error
+
+
+def is_root():
+    return os.getuid() == 0
+
+
+def ask_root_password(locale_keys: dict):
+
+    dialog_pwd = QInputDialog()
+    dialog_pwd.setInputMode(QInputDialog.TextInput)
+    dialog_pwd.setTextEchoMode(QLineEdit.Password)
+    dialog_pwd.setWindowTitle(locale_keys['popup.root.title'])
+    dialog_pwd.setLabelText(locale_keys['popup.root.password'] + ':')
+    dialog_pwd.setCancelButtonText(locale_keys['popup.button.cancel'])
+    dialog_pwd.resize(400, 200)
+
+    ok = dialog_pwd.exec_()
+
+    if ok:
+        if not validate_password(dialog_pwd.textValue()):
+            show_error(title=locale_keys['popup.root.bad_password.title'],
+                       body=locale_keys['popup.root.bad_password.body'])
+            ok = False
+
+    return dialog_pwd.textValue(), ok
+
+
+def validate_password(password: str) -> bool:
+    f = os.popen('echo {} | sudo -S whoami'.format(password))
+    res = f.read()
+    f.close()
+
+    return bool(res.strip())

fpakman/view/qt/systray.py

@@ -4,6 +4,7 @@ import time
 from PyQt5.QtCore import QThread, pyqtSignal, QCoreApplication
 from PyQt5.QtGui import QIcon
 from PyQt5.QtWidgets import QSystemTrayIcon, QMenu
+from fpakman.core.model import FlatpakManager
 
 from fpakman.core import resource
 from fpakman.core.controller import FlatpakController
@@ -34,10 +35,11 @@ class UpdateCheck(QThread):
 
 class TrayIcon(QSystemTrayIcon):
 
-    def __init__(self, locale_keys: dict, controller: FlatpakController, check_interval: int = 60):
+    def __init__(self, locale_keys: dict, controller: FlatpakController, manager: FlatpakManager, check_interval: int = 60):
         super(TrayIcon, self).__init__()
         self.locale_keys = locale_keys
         self.controller = controller
+        self.manager = manager
 
         self.icon_default = QIcon(resource.get_path('img/flathub_45.svg'))
         self.icon_update = QIcon(resource.get_path('img/update_logo.svg'))
@@ -50,7 +52,7 @@ class TrayIcon(QSystemTrayIcon):
         self.action_exit.triggered.connect(lambda: QCoreApplication.exit())
         self.setContextMenu(self.menu)
 
-        self.manage_window = ManageWindow(locale_keys=self.locale_keys, controller=controller, tray_icon=self)
+        self.manage_window = ManageWindow(locale_keys=self.locale_keys, controller=controller, manager=self.manager, tray_icon=self)
         self.check_thread = UpdateCheck(check_interval=check_interval, controller=self.controller)
         self.check_thread.signal.connect(self.notify_updates)
         self.check_thread.start()

fpakman/view/qt/window.py

@@ -7,18 +7,21 @@ from PyQt5.QtCore import QThread, pyqtSignal, QEvent
 from PyQt5.QtGui import QIcon, QWindowStateChangeEvent
 from PyQt5.QtWidgets import QWidget, QVBoxLayout, QApplication, QCheckBox, QHeaderView, QToolButton, QToolBar, \
     QSizePolicy, QLabel, QMessageBox, QPlainTextEdit
+from fpakman.core.model import FlatpakManager, ImpossibleDowngradeException
 
 from fpakman import __version__
 from fpakman.core import resource
 from fpakman.core.controller import FlatpakController
+from fpakman.view.qt import dialog
 from fpakman.view.qt.apps_table import AppsTable
+from fpakman.view.qt.root import is_root, ask_root_password
 
 
 class ManageWindow(QWidget):
 
     __BASE_HEIGHT__ = 400
 
-    def __init__(self, locale_keys: dict, controller: FlatpakController, tray_icon = None):
+    def __init__(self, locale_keys: dict, controller: FlatpakController, manager: FlatpakManager, tray_icon = None):
         super(ManageWindow, self).__init__()
         self.locale_keys = locale_keys
         self.column_names = [locale_keys['manage_window.columns.name'],
@@ -30,6 +33,7 @@ class ManageWindow(QWidget):
                              locale_keys['manage_window.columns.origin'],
                              locale_keys['manage_window.columns.update']]
         self.controller = controller
+        self.manager = manager
         self.tray_icon = tray_icon
         self.thread_lock = Lock()
         self.working = False  # restrict the number of threaded actions
@@ -104,6 +108,10 @@ class ManageWindow(QWidget):
         self.thread_uninstall.signal_output.connect(self._update_action_output)
         self.thread_uninstall.signal_finished.connect(self._finish_uninstall)
 
+        self.thread_downgrade = DowngradeApp(self.manager)
+        self.thread_downgrade.signal_output.connect(self._update_action_output)
+        self.thread_downgrade.signal_finished.connect(self._finish_downgrade)
+
         self.toolbar_bottom = QToolBar()
         self.label_updates = QLabel('')
         self.toolbar_bottom.addWidget(self.label_updates)
@@ -132,12 +140,9 @@ class ManageWindow(QWidget):
     def _check_flatpak_installed(self):
 
         if not self.controller.check_installed():
-            error_msg = QMessageBox()
+            dialog.show_error(title=self.locale_keys['popup.flatpak_not_installed.title'],
-            error_msg.setIcon(QMessageBox.Critical)
+                              body=self.locale_keys['popup.flatpak_not_installed.msg'] + '...',
-            error_msg.setWindowTitle(self.locale_keys['popup.flatpak_not_installed.title'])
+                              icon=self.icon_flathub)
-            error_msg.setText(self.locale_keys['popup.flatpak_not_installed.msg'] + '...')
-            error_msg.setWindowIcon(self.icon_flathub)
-            error_msg.exec_()
             exit(1)
 
         if self.label_flatpak:
@@ -199,6 +204,11 @@ class ManageWindow(QWidget):
         self._release_lock()
         self.refresh(clear_output=False)
 
+    def _finish_downgrade(self):
+        self.finish_action()
+        self._release_lock()
+        self.refresh(clear_output=False)
+
     def filter_only_apps(self, only_apps: int):
 
         if self.apps:
@@ -318,6 +328,29 @@ class ManageWindow(QWidget):
         self.table_apps.setEnabled(True)
         self.label_status.setText('')
 
+    def downgrade_app(self, app_ref: str):
+
+        self._check_flatpak_installed()
+
+        if self._acquire_lock():
+
+            pwd = None
+
+            if not is_root():
+                pwd, ok = ask_root_password(self.locale_keys)
+
+                if not ok:
+                    self._release_lock()
+                    return
+
+            self.textarea_output.clear()
+            self.textarea_output.setVisible(True)
+            self._begin_action(self.locale_keys['manage_window.status.downgrading'] + '...')
+
+            self.thread_downgrade.app_ref = app_ref
+            self.thread_downgrade.root_password = pwd
+            self.thread_downgrade.start()
+
 
 # Threaded actions
 class UpdateSelectedApps(QThread):
@@ -372,3 +405,31 @@ class UninstallApp(QThread):
                     self.signal_output.emit(line)
 
             self.signal_finished.emit()
+
+
+class DowngradeApp(QThread):
+    signal_finished = pyqtSignal()
+    signal_output = pyqtSignal(str)
+
+    def __init__(self, manager: FlatpakManager):
+        super(DowngradeApp, self).__init__()
+        self.manager = manager
+        self.app_ref = None
+        self.root_password = None
+
+    def run(self):
+        if self.app_ref:
+            try:
+                for output in self.manager.downgrade_app(self.app_ref, self.root_password):
+                    line = output.decode().strip()
+                    if line:
+                        self.signal_output.emit(line)
+
+            except ImpossibleDowngradeException:
+                dialog.show_error(title=self.locale_keys['popup.downgrade.impossible.title'],
+                                  body=self.locale_keys['popup.downgrade.impossible.body'],
+                                  icon=self.icon_flathub)
+
+            self.app_ref = None
+            self.root_password = None
+            self.signal_finished.emit()