Merge pull request #400 from kartoza/timlinux/issue388

Implementation for #388 point a nd line analysis

config.json

@@ -16,7 +16,7 @@
     "author": "Kartoza",
     "email": "[email protected]",
     "description": "Gender Enabling Environments Spatial Tool",
-    "version": "0.1.1",
+    "version": "0.1.4",
     "changelog": "",
     "server": false
   }

geest/core/algorithms/area_iterator.py

@@ -0,0 +1,129 @@
+from qgis.core import (
+    QgsFeatureRequest,
+    QgsMessageLog,
+    QgsVectorLayer,
+    QgsProject,
+    QgsGeometry,
+    Qgis,
+)
+from typing import Iterator, Tuple
+
+
+class AreaIterator:
+    """
+    An iterator to yield pairs of geometries from polygon and bbox layers
+    found in a GeoPackage file, along with a progress percentage.
+
+    Attributes:
+        gpkg_path (str): The path to the GeoPackage file.
+
+    Precondition:
+        study_area_polygons (QgsVectorLayer): The vector layer containing polygons.
+        study_area_bboxes (QgsVectorLayer): The vector layer containing bounding boxes.
+
+        There should be a one-to-one correspondence between the polygons and bounding boxes.
+
+    Example usage:
+        To use the iterator, simply pass the path to the GeoPackage:
+
+        ```python
+        gpkg_path = '/path/to/your/geopackage.gpkg'
+        area_iterator = AreaIterator(gpkg_path)
+
+        for polygon_geometry, bbox_geometry, progress_percent in area_iterator:
+            QgsMessageLog.logMessage(f"Polygon Geometry: {polygon_geometry.asWkt()}", 'Geest')
+            QgsMessageLog.logMessage(f"BBox Geometry: {bbox_geometry.asWkt()}", 'Geest')
+            QgsMessageLog.logMessage(f"Progress: {progress_percent:.2f}%", 'Geest')
+        ```
+    """
+
+    def __init__(self, gpkg_path: str) -> None:
+        """
+        Initialize the AreaIterator with the path to the GeoPackage.
+
+        Args:
+            gpkg_path (str): The file path to the GeoPackage.
+        """
+        self.gpkg_path = gpkg_path
+
+        # Load the polygon and bbox layers from the GeoPackage
+        self.polygon_layer: QgsVectorLayer = QgsVectorLayer(
+            f"{gpkg_path}|layername=study_area_polygons", "study_area_polygons", "ogr"
+        )
+        self.bbox_layer: QgsVectorLayer = QgsVectorLayer(
+            f"{gpkg_path}|layername=study_area_bboxes", "study_area_bboxes", "ogr"
+        )
+
+        # Verify that both layers were loaded correctly
+        if not self.polygon_layer.isValid():
+            QgsMessageLog.logMessage(
+                "Error: 'study_area_polygons' layer failed to load from the GeoPackage",
+                "Geest",
+                level=Qgis.Critical,
+            )
+            raise ValueError(
+                "Failed to load 'study_area_polygons' layer from the GeoPackage."
+            )
+
+        if not self.bbox_layer.isValid():
+            QgsMessageLog.logMessage(
+                "Error: 'study_area_bboxes' layer failed to load from the GeoPackage",
+                "Geest",
+                level=Qgis.Critical,
+            )
+            raise ValueError(
+                "Failed to load 'study_area_bboxes' layer from the GeoPackage."
+            )
+
+        # Get the total number of polygon features for progress calculation
+        self.total_features: int = self.polygon_layer.featureCount()
+
+    def __iter__(self) -> Iterator[Tuple[QgsGeometry, QgsGeometry, float]]:
+        """
+        Iterator that yields pairs of geometries from the polygon layer and the corresponding bbox layer,
+        along with a progress percentage.
+
+        Yields:
+            Iterator[Tuple[QgsGeometry, QgsGeometry, float]]: Yields a tuple of polygon and bbox geometries,
+            along with a progress value representing the percentage of the iteration completed.
+        """
+        try:
+            # Ensure both layers have the same CRS
+            if self.polygon_layer.crs() != self.bbox_layer.crs():
+                QgsMessageLog.logMessage(
+                    "Warning: CRS mismatch between polygon and bbox layers",
+                    "Geest",
+                    level=Qgis.Warning,
+                )
+                return
+
+            # Iterate over each polygon feature and calculate progress
+            for index, polygon_feature in enumerate(self.polygon_layer.getFeatures()):
+                polygon_id: int = polygon_feature.id()
+
+                # Request the corresponding bbox feature based on the polygon's ID
+                bbox_request: QgsFeatureRequest = QgsFeatureRequest().setFilterFid(
+                    polygon_id
+                )
+                bbox_feature = next(self.bbox_layer.getFeatures(bbox_request), None)
+
+                if bbox_feature:
+                    # Calculate the progress as the percentage of features processed
+                    progress_percent: float = ((index + 1) / self.total_features) * 100
+
+                    # Yield a tuple with polygon geometry, bbox geometry, and progress percentage
+                    yield polygon_feature.geometry(), bbox_feature.geometry(), progress_percent
+
+                else:
+                    QgsMessageLog.logMessage(
+                        f"Warning: No matching bbox found for polygon ID {polygon_id}",
+                        "Geest",
+                        level=Qgis.Warning,
+                    )
+
+        except Exception as e:
+            QgsMessageLog.logMessage(
+                f"Critical: Error during iteration - {str(e)}",
+                "Geest",
+                level=Qgis.Critical,
+            )