grass.jupyter: Allow users to draw simple geometries and save it as vector

python/grass/jupyter/interactivemap.py

@@ -22,6 +22,7 @@
     reproject_region,
     update_region,
     get_location_proj_string,
+    save_vector,
 )
 
 
@@ -353,6 +354,101 @@ def add_layer_control(self, **kwargs):
         else:
             self.layer_control_object = self._ipyleaflet.LayersControl(**kwargs)
 
+    def setup_drawing_interface(self):
+        """
+        Allow Users to draw Geometry and Save/Delete them.
+        """
+        import ipywidgets as widgets  # pylint: disable=import-outside-toplevel
+
+        draw_control = self._ipyleaflet.DrawControl(edit=False, remove=False)
+        drawn_geometries = []
+        geo_json_layers = {}
+        save_button_control = None
+
+        def handle_draw(_target, action, geo_json):
+            if action == "created":
+                drawn_geometries.append(geo_json)
+                print(f"Geometry created: {geo_json}")
+
+        draw_control.on_draw(handle_draw)
+
+        draw_button = widgets.ToggleButton(
+            icon="pencil",
+            value=False,
+            tooltip="Click to draw geometries",
+            layout=widgets.Layout(width="33px", margin="0px 0px 0px 0px"),
+        )
+
+        def toggle_geometry(change):
+            if change["new"]:
+                self.map.add_control(draw_control)
+                show_interface()
+            else:
+                drawn_geometries.clear()
+                self.map.remove_control(draw_control)
+                hide_interface()
+
+        draw_button.observe(toggle_geometry, names="value")
+
+        def show_interface():
+            nonlocal save_button_control
+
+            name_input = widgets.Text(
+                description="New vector map name:",
+                style={"description_width": "initial"},
+                layout=widgets.Layout(
+                    width="80%",
+                    margin="1px 1px 1px 1px",
+                ),
+            )
+            save_button = widgets.Button(
+                description="Save",
+                layout=widgets.Layout(width="20%", margin="1px 1px 1px 1px"),
+            )
+
+            def save_geometries(_b):
+                name = name_input.value
+                if name and drawn_geometries:
+                    for geometry in drawn_geometries:
+                        geometry["properties"]["name"] = name
+                    geo_json = {
+                        "type": "FeatureCollection",
+                        "features": drawn_geometries,
+                    }
+                    save_vector(name, geo_json)
+                    geo_json_layer = self._ipyleaflet.GeoJSON(data=geo_json, name=name)
+                    geo_json_layers[name] = geo_json_layer
+                    self.map.add_layer(geo_json_layer)
+                    draw_control.clear()
+                    drawn_geometries.clear()
+
+            save_button.on_click(save_geometries)
+
+            hbox_layout = widgets.Layout(
+                display="flex",
+                flex_flow="row",
+                align_items="stretch",
+                width="300px",
+                justify_content="space-between",
+            )
+
+            save_button_control = self._ipyleaflet.WidgetControl(
+                widget=widgets.HBox([name_input, save_button], layout=hbox_layout),
+                position="topright",
+            )
+
+            self.map.add_control(save_button_control)
+
+        def hide_interface():
+            nonlocal save_button_control
+            drawn_geometries.clear()
+            if save_button_control:
+                self.map.remove_control(save_button_control)
+                save_button_control = None
+
+        toggle_control = self._ipyleaflet.WidgetControl(widget=draw_button)
+        self.map.add_control(toggle_control)
+
     def draw_computational_region(self):
         """
         Allow users to draw the computational region and modify it.
@@ -481,6 +577,8 @@ def show(self):
             return fig
 
         # ipyleaflet
+        if self._ipyleaflet:
+            self.setup_drawing_interface()
         self.map.add(self.layer_control_object)
         return self.map
 

python/grass/jupyter/utils.py

@@ -10,6 +10,9 @@
 #            for details.
 
 """Utility functions warpping existing processes in a suitable way"""
+import tempfile
+import json
+
 from pathlib import Path
 import grass.script as gs
 
@@ -201,6 +204,23 @@ def get_rendering_size(region, width, height, default_width=600, default_height=
     return (default_width, round(default_width * region_height / region_width))
 
 
+def save_vector(name, geo_json):
+    """
+    Saves the user drawn vector.
+
+    param geojson_filename: name of the geojson file to be saved
+    param name: name with which vector should be saved
+    """
+    with tempfile.NamedTemporaryFile(
+        suffix=".geojson", delete=False, mode="w"
+    ) as temp_file:
+        temp_filename = temp_file.name
+        for each in geo_json["features"]:
+            each["properties"].clear()
+        json.dump(geo_json, temp_file)
+    gs.run_command("v.import", input=temp_filename, output=name)
+
+
 def get_region_bounds_latlon():
     """Gets the current computational region bounds in latlon."""
     region = gs.parse_command("g.region", flags="gbp")