Import iface in lazy manner

ee_plugin/Map.py

@@ -13,8 +13,17 @@
     QgsProject,
     QgsRectangle,
 )
+from qgis import gui
 from qgis.PyQt.QtCore import QEventLoop, QTimer, QCoreApplication, QThread
-from qgis.utils import iface
+
+from . import utils
+
+
+def get_iface() -> gui.QgisInterface:
+    # Lazy import to ensure that iface is available after gqis is initialized
+    from qgis.utils import iface
+
+    return iface
 
 
 def addLayer(eeObject, visParams=None, name=None, shown=True, opacity=1.0):
@@ -27,8 +36,6 @@ def addLayer(eeObject, visParams=None, name=None, shown=True, opacity=1.0):
         >>> from ee_plugin import Map
         >>> Map.addLayer(.....)
     """
-    from . import utils
-
     utils.add_or_update_ee_layer(eeObject, visParams, name, shown, opacity)
 
 
@@ -67,7 +74,7 @@ def centerObject(feature, zoom=None):
         rect_proj = geo2proj.transform(rect)
 
         # center geometry
-        iface.mapCanvas().zoomToFeatureExtent(rect_proj)
+        get_iface().mapCanvas().zoomToFeatureExtent(rect_proj)
     else:
         # set map center to feature centroid at a specified zoom
         center = feature.geometry().centroid().coordinates().getInfo()
@@ -85,7 +92,7 @@ def getBounds(asGeoJSON=False):
         >>> bounds = Map.getBounds(True)
         >>> Map.addLayer(bounds, {}, 'bounds')
     """
-    ex = iface.mapCanvas().extent()
+    ex = get_iface().mapCanvas().extent()
     # return ex
     xmax = ex.xMaximum()
     ymax = ex.yMaximum()
@@ -97,7 +104,7 @@ def getBounds(asGeoJSON=False):
         return [xmin, ymin, xmax, ymax]
 
     # return as geometry
-    crs = iface.mapCanvas().mapSettings().destinationCrs().authid()
+    crs = get_iface().mapCanvas().mapSettings().destinationCrs().authid()
 
     return ee.Geometry.Rectangle([xmin, ymin, xmax, ymax], crs, False)
 
@@ -113,9 +120,9 @@ def getCenter():
         >>> center = Map.getCenter()
         >>> Map.addLayer(center, { 'color': 'red' }, 'center')
     """
-    center = iface.mapCanvas().center()
+    center = get_iface().mapCanvas().center()
 
-    crs = iface.mapCanvas().mapSettings().destinationCrs().authid()
+    crs = get_iface().mapCanvas().mapSettings().destinationCrs().authid()
 
     return ee.Geometry.Point([center.x(), center.y()], crs)
 
@@ -143,13 +150,13 @@ def setCenter(lon, lat, zoom=None):
     xform = QgsCoordinateTransform(crsSrc, crsDest, QgsProject.instance())
     # forward transformation: src -> dest
     center_point = xform.transform(center_point_in)
-    iface.mapCanvas().setCenter(center_point)
+    get_iface().mapCanvas().setCenter(center_point)
 
     ### zoom
     if zoom is not None:
         # transform the zoom level to scale
         scale_value = 591657550.5 / 2 ** (zoom - 1)
-        iface.mapCanvas().zoomScale(scale_value)
+        get_iface().mapCanvas().zoomScale(scale_value)
 
 
 def getScale():
@@ -163,7 +170,7 @@ def getScale():
         >>> print(Map.getScale())
     """
 
-    return iface.mapCanvas().scale() / 1000
+    return get_iface().mapCanvas().scale() / 1000
 
 
 def getZoom():
@@ -180,8 +187,8 @@ def getZoom():
     """
 
     # from https://gis.stackexchange.com/questions/268890/get-current-zoom-level-from-qgis-map-canvas
-    scale = iface.mapCanvas().scale()
-    dpi = iface.mainWindow().physicalDpiX()
+    scale = get_iface().mapCanvas().scale()
+    dpi = get_iface().mainWindow().physicalDpiX()
     maxScalePerPixel = 156543.04
     inchesPerMeter = 39.37
     zoom = math.log((dpi * inchesPerMeter * maxScalePerPixel / scale), 2)