Convert label zoom range

felt/core/fsl_converter.py

@@ -46,6 +46,8 @@
     QgsStringUtils
 )
 
+from .map_utils import MapUtils
+
 
 class LogLevel(Enum):
     """
@@ -1192,6 +1194,11 @@ def label_settings_to_fsl(settings: QgsPalLayerSettings,
         )
         if settings.autoWrapLength > 0:
             converted_format['maxLineChars'] = settings.autoWrapLength
+        if settings.scaleVisibility:
+            converted_format['minZoom'] = MapUtils.map_scale_to_leaflet_tile_zoom(
+                settings.minimumScale)
+            converted_format['maxZoom'] = MapUtils.map_scale_to_leaflet_tile_zoom(
+                settings.maximumScale)
 
         res = {
             'config': {
@@ -1200,9 +1207,6 @@ def label_settings_to_fsl(settings: QgsPalLayerSettings,
             'label': converted_format
         }
 
-        # maxZoom
-        # minZoom
-
         # For now, we don't convert these and leave them to the Felt
         # defaults -- there's too many other unsupported placement
         # related configuration settings in QGIS which impact on the

felt/core/map_utils.py

@@ -1,4 +1,3 @@
-# -*- coding: utf-8 -*-
 """Map utilities
 
 .. note:: This program is free software; you can redistribute it and/or modify
@@ -7,12 +6,6 @@
 (at your option) any later version.
 """
 
-__author__ = '(C) 2018 by Nyall Dawson'
-__date__ = '20/04/2018'
-__copyright__ = 'Copyright 2018, North Road'
-# This will get replaced with a git SHA1 when you do a git archive
-__revision__ = '$Format:%H$'
-
 from qgis.PyQt.QtCore import (
     QSize
 )
@@ -54,6 +47,23 @@ class MapUtils:
         70.5310735
     ]
 
+    @staticmethod
+    def map_scale_to_leaflet_tile_zoom(
+            scale: float
+    ) -> int:
+        """
+        Returns the leaflet tile zoom level roughly
+        corresponding to a QGIS map scale
+        """
+        for level, min_scale in enumerate(MapUtils.ZOOM_LEVEL_SCALE_BREAKS):
+            if min_scale < scale:
+                # we play it safe and zoom out a step -- this is because
+                # we don't know the screen size or DPI on which the map
+                # will actually be viewed, so we err on the conservative side
+                return level - 1
+
+        return len(MapUtils.ZOOM_LEVEL_SCALE_BREAKS) - 1
+
     @staticmethod
     def calculate_leaflet_tile_zoom_for_extent(
             extent: QgsReferencedRectangle,
@@ -74,12 +84,4 @@ def calculate_leaflet_tile_zoom_for_extent(
         map_settings.setOutputSize(target_map_size)
 
         scale = map_settings.scale()
-
-        for level, min_scale in enumerate(MapUtils.ZOOM_LEVEL_SCALE_BREAKS):
-            if min_scale < scale:
-                # we play it safe and zoom out a step -- this is because
-                # we don't know the screen size or DPI on which the map
-                # will actually be viewed, so we err on the conservative side
-                return level - 1
-
-        return len(MapUtils.ZOOM_LEVEL_SCALE_BREAKS) - 1
+        return MapUtils.map_scale_to_leaflet_tile_zoom(scale)

felt/test/test_fsl_conversion.py

@@ -1655,6 +1655,25 @@ def test_label_settings(self):
         )
         label_settings.autoWrapLength = 0
 
+        # zoom ranges
+        label_settings.scaleVisibility = True
+        label_settings.minimumScale = 5677474
+        label_settings.maximumScale = 34512
+        self.assertEqual(
+            FslConverter.label_settings_to_fsl(label_settings, context),
+            {'config': {'labelAttribute': 'my_field'},
+             'label': {'color': 'rgba(255, 0, 0, 0.3)',
+                       'fontSize': 13,
+                       'fontStyle': 'normal',
+                       'fontWeight': 400,
+                       'haloColor': 'rgba(0, 0, 0, 0)',
+                       'haloWidth': 4,
+                       'letterSpacing': 0.0,
+                       'lineHeight': 1.0,
+                       'maxZoom': 14,
+                       'minZoom': 6}}
+        )
+
 
 if __name__ == "__main__":
     suite = unittest.makeSuite(FslConversionTest)