How to retrieve the coordinates on-click and save it as a variable?

[hamiddashti]

Hi, I like to retrieve the coordinates when I click on a map and save them in a variable for further processing. There is an example provided by geemap (here):

import ee
import geemap
import ipywidgets as widgets
from ipyleaflet import WidgetControl
Map = geemap.Map()
Map

# Add an output widget to the map
output_widget = widgets.Output(layout={'border': '1px solid black'})
output_control = WidgetControl(widget=output_widget, position='bottomright')
Map.add_control(output_control)

# Capture user interaction with the map
def handle_interaction(**kwargs):
    latlon = kwargs.get('coordinates')
    if kwargs.get('type') == 'click':
        Map.default_style = {'cursor': 'wait'}
        # xy = ee.Geometry.Point(latlon[::-1])

        with output_widget:
            output_widget.clear_output()
            print(latlon)
    Map.default_style = {'cursor': 'pointer'}


Map.on_interaction(handle_interaction)

This shows the coordinates on the map but there are two issues, I don't know how to save the coordinates in a variable that I can use later, and secondly, I cannot move the map since when I click and hold the mouse to move the map, it only returns the coordinates. I wonder is there a way to save and update a variable that contains the on-click coordinates extracted from the above code?

Thanks

[giswqs]

You can create an attribute for the Map (.e.g., Map.points = []), and append points to the list with mouse click events. Then retrieve the points using Map.points

import ee
import geemap
import ipywidgets as widgets
from ipyleaflet import WidgetControl
Map = geemap.Map()
Map.points = []

# Add an output widget to the map
output_widget = widgets.Output(layout={'border': '1px solid black'})
output_control = WidgetControl(widget=output_widget, position='bottomright')
Map.add_control(output_control)

# Capture user interaction with the map
def handle_interaction(**kwargs):
    latlon = kwargs.get('coordinates')
    if kwargs.get('type') == 'click':
        Map.default_style = {'cursor': 'wait'}
        # xy = ee.Geometry.Point(latlon[::-1])

        with output_widget:
            output_widget.clear_output()
            print(latlon)
        Map.points.append(latlon)
    Map.default_style = {'cursor': 'pointer'}

Map.on_interaction(handle_interaction)

Map

Map.points

[KBodolai]

Just to add to this, I recently needed to do something similar, and realised that the code above does as intended, but it will append a point for each interaction with the map, so just moving the mouse around will trigger points being added to the Map.points list.

by rearranging the code a bit you can get it to only save the points:

import ee
import geemap
import ipywidgets as widgets
from ipyleaflet import WidgetControl
Map = geemap.Map()
Map.points = []

# Add an output widget to the map
output_widget = widgets.Output(layout={'border': '1px solid black'})
output_control = WidgetControl(widget=output_widget, position='bottomright')
Map.add_control(output_control)

# Capture user interaction with the map
def handle_interaction(**kwargs):

    if kwargs.get('type') == 'click':
        latlon = kwargs.get('coordinates')
        Map.default_style = {'cursor': 'wait'}

        with output_widget:
            output_widget.clear_output()
            print(latlon)
        Map.points.append(latlon)
        Map.default_style = {'cursor': 'pointer'}

Map.on_interaction(handle_interaction)

Map

Dropping it here in case it helps somebody in the future!

[MauroAndretta]

Thanks for sharing it, just what I was looking for!
By chance do you have also a version for which we get all the information when we draw a polygon on the map?

[giswqs]

Map.user_roi

[MauroAndretta]

Thank you so much!