test_pdfcontroller: Get rid of platform specifics

As system() called PDF controllers are removed, test_pdfcontroller can be
simplified because PyMuPDF will use the mocked screen.
Get rid of the platform-dependent screen size obtaining which gets rid of
the Xlib dependency.

scripts/check_dependencies.py

@@ -58,7 +58,6 @@ LINUX_MODULES = [
     # Optical drive detection.
     'dbus',
     'distro',
-    'Xlib',
 ]
 
 MACOSX_MODULES = [

setup.py

@@ -138,7 +138,6 @@ using a computer and a data projector.""",
             'pysword',
             'pytest',
             'pytest-qt',
-            'python-xlib; platform_system=="Linux"',
             'flake8',
         ]
     },

tests/functional/openlp_plugins/presentations/test_pdfcontroller.py

@@ -26,12 +26,10 @@ import pytest
 from pathlib import Path
 from shutil import rmtree
 from tempfile import mkdtemp
-from unittest import skipIf
 from unittest.mock import MagicMock
 
 from PyQt5 import QtCore, QtGui
 
-from openlp.core.common import is_macosx, is_linux, is_win
 from openlp.core.display.screens import ScreenList
 from openlp.plugins.presentations.lib.pdfcontroller import PdfController, PdfDocument
 from tests.utils.constants import RESOURCE_PATH
@@ -47,41 +45,11 @@ def pdf_env(settings, mock_plugin, mocked_qapp):
     mocked_qapp.primaryScreen = MagicMock()
     mocked_qapp.primaryScreen.return_value = mocked_screen
     ScreenList.create(mocked_qapp)
-    yield settings, mock_plugin, temp_folder_path, thumbnail_folder_path
+    yield mock_plugin, temp_folder_path, thumbnail_folder_path
     rmtree(thumbnail_folder_path)
     rmtree(temp_folder_path)
 
 
-SCREEN = {
-    'primary': False,
-    'number': 1,
-    'size': QtCore.QRect(0, 0, 1024, 768)
-}
-IS_CI = 'GITLAB_CI' in os.environ or 'APPVEYOR' in os.environ
-IS_QT_QPA_PLATFORM_OFFSCREEN = 'QT_QPA_PLATFORM' in os.environ and os.environ['QT_QPA_PLATFORM'] == 'offscreen'
-
-
-def get_screen_resolution():
-    """
-    Get the screen resolution
-    """
-    if is_macosx():
-        # Magic numbers... don't ask me why
-        return 1024, 768
-    elif is_win():
-        from win32api import GetSystemMetrics
-        return GetSystemMetrics(0), GetSystemMetrics(1)
-    elif is_linux():
-        if IS_CI:
-            return 1024, 768
-        else:
-            from Xlib.display import Display
-            resolution = Display().screen().root.get_geometry()
-            return resolution.width, resolution.height
-    else:
-        return 1024, 768
-
-
 def test_constructor(settings, mock_plugin):
     """
     Test the Constructor from the PdfController
@@ -104,9 +72,9 @@ def load_pdf(pdf_env):
     test_file_path = RESOURCE_PATH / 'presentations' / 'pdf_test1.pdf'
 
     # WHEN: The Pdf is loaded
-    mock_plugin = pdf_env[1]
-    temp_folder_path = pdf_env[2]
-    thumbnail_folder_path = pdf_env[3]
+    mock_plugin = pdf_env[0]
+    temp_folder_path = pdf_env[1]
+    thumbnail_folder_path = pdf_env[2]
     controller = PdfController(plugin=mock_plugin)
     controller.temp_folder = temp_folder_path
     controller.thumbnail_folder = thumbnail_folder_path
@@ -118,7 +86,6 @@ def load_pdf(pdf_env):
     assert 3 == document.get_slide_count(), 'The pagecount of the PDF should be 3.'
 
 
-@skipIf(IS_QT_QPA_PLATFORM_OFFSCREEN, 'This test fails when QT_QPA_PLATFORM is set to "offscreen".')
 def load_pdf_pictures(pdf_env):
     """
     Test loading a Pdf and check the generated pictures' size
@@ -127,9 +94,9 @@ def load_pdf_pictures(pdf_env):
     test_file_path = RESOURCE_PATH / 'presentations' / 'pdf_test1.pdf'
 
     # WHEN: The Pdf is loaded
-    mock_plugin = pdf_env[1]
-    temp_folder_path = pdf_env[2]
-    thumbnail_folder_path = pdf_env[3]
+    mock_plugin = pdf_env[0]
+    temp_folder_path = pdf_env[1]
+    thumbnail_folder_path = pdf_env[2]
     controller = PdfController(plugin=mock_plugin)
     controller.temp_folder = temp_folder_path
     controller.thumbnail_folder = thumbnail_folder_path
@@ -139,9 +106,8 @@ def load_pdf_pictures(pdf_env):
     # THEN: The load should succeed and pictures should be created and have been scaled to fit the screen
     assert loaded is True, 'The loading of the PDF should succeed.'
     image = QtGui.QImage(os.path.join(str(temp_folder_path), 'pdf_test1.pdf', 'mainslide001.png'))
-    # Based on the converter used the resolution will differ a bit
-    width, height = get_screen_resolution()
     # Calculate the width of the PDF based on the aspect ratio of the PDF
+    height = 768
     width = int(round(height * 0.70703125, 0))
     assert image.height() == height, 'The height should be {height}'.format(height=height)
     assert image.width() == width, 'The width should be {width}'.format(width=width)