Fixed structure

amcr_viewer/test/utilities.py

@@ -0,0 +1,61 @@
+# coding=utf-8
+"""Common functionality used by regression tests."""
+
+import sys
+import logging
+
+
+LOGGER = logging.getLogger('QGIS')
+QGIS_APP = None  # Static variable used to hold hand to running QGIS app
+CANVAS = None
+PARENT = None
+IFACE = None
+
+
+def get_qgis_app():
+    """ Start one QGIS application to test against.
+
+    :returns: Handle to QGIS app, canvas, iface and parent. If there are any
+        errors the tuple members will be returned as None.
+    :rtype: (QgsApplication, CANVAS, IFACE, PARENT)
+
+    If QGIS is already running the handle to that app will be returned.
+    """
+
+    try:
+        from qgis.PyQt import QtGui, QtCore
+        from qgis.core import QgsApplication
+        from qgis.gui import QgsMapCanvas
+        from .qgis_interface import QgisInterface
+    except ImportError:
+        return None, None, None, None
+
+    global QGIS_APP  # pylint: disable=W0603
+
+    if QGIS_APP is None:
+        gui_flag = True  # All test will run qgis in gui mode
+        #noinspection PyPep8Naming
+        QGIS_APP = QgsApplication(sys.argv, gui_flag)
+        # Make sure QGIS_PREFIX_PATH is set in your env if needed!
+        QGIS_APP.initQgis()
+        s = QGIS_APP.showSettings()
+        LOGGER.debug(s)
+
+    global PARENT  # pylint: disable=W0603
+    if PARENT is None:
+        #noinspection PyPep8Naming
+        PARENT = QtGui.QWidget()
+
+    global CANVAS  # pylint: disable=W0603
+    if CANVAS is None:
+        #noinspection PyPep8Naming
+        CANVAS = QgsMapCanvas(PARENT)
+        CANVAS.resize(QtCore.QSize(400, 400))
+
+    global IFACE  # pylint: disable=W0603
+    if IFACE is None:
+        # QgisInterface is a stub implementation of the QGIS plugin interface
+        #noinspection PyPep8Naming
+        IFACE = QgisInterface(CANVAS)
+
+    return QGIS_APP, CANVAS, IFACE, PARENT