Documentation: example using startActivityForResult with bind(on_activity_result=)

[arlowhite]

I'd like to contribute some documentation. This code opens the Android Photo Gallery and gets the filepath of the selected image.
It took me a few hours to figure out how to do this. The only discussion on it I could find was here:
https://groups.google.com/forum/#!msg/kivy-users/bjsG2j9bptI/-Oe_aGo0newJ

I think it would helpful if an example like this was in the official documentation somewhere. However, I'm not sure if it should be in the p4a or pyjnius docs.
http://python-for-android.readthedocs.org/en/latest/examples/
http://pyjnius.readthedocs.org/en/latest/android.html#accessing-the-activity

I'd be willing to create the documentation and do a pull request, just let me know:

1. Where the documentation should go
2. Any problems with the code below that sets a bad example or other things to change in the example

Just realized, should I activity.unbind at the end of the on_activity_result function?

from kivy.logger import Logger
from kivy.clock import Clock

from jnius import autoclass
from jnius import cast

# python-for-android provides this
from android import activity

PythonActivity = autoclass('org.renpy.android.PythonActivity')
Intent = autoclass('android.content.Intent')
Uri = autoclass('android.net.Uri')

# Value of MediaStore.Images.Media.DATA
MediaStore_Images_Media_DATA = "_data"

# Custom request codes
RESULT_LOAD_IMAGE = 1

Activity = autoclass('android.app.Activity')
# Activity is only used to get these codes. Could just hardcode them.
    # /** Standard activity result: operation canceled. */
    # public static final int RESULT_CANCELED    = 0;
    # /** Standard activity result: operation succeeded. */
    # public static final int RESULT_OK           = -1;
    # /** Start of user-defined activity results. */
    # Not sure what this means
    # public static final int RESULT_FIRST_USER   = 1;

def user_select_image(callback):
    """Open Gallery Activity and call callback with absolute image filepath of image user selected.
    None if user canceled.
    """

    # PythonActivity.mActivity is the instance of the current Activity
    # BUT, startActivity is a method from the Activity class, not from our
    # PythonActivity.
    # We need to cast our class into an activity and use it
    currentActivity = cast('android.app.Activity', PythonActivity.mActivity)

    # Forum discussion: https://groups.google.com/forum/#!msg/kivy-users/bjsG2j9bptI/-Oe_aGo0newJ
    def on_activity_result(request_code, result_code, intent):
        if request_code != RESULT_LOAD_IMAGE:
            Logger.warning('user_select_image: ignoring activity result that was not RESULT_LOAD_IMAGE')
            return

        if result_code == Activity.RESULT_CANCELED:
            Clock.schedule_once(lambda dt: callback(None), 0)
            return

        if result_code != Activity.RESULT_OK:
            # This may just go into the void...
            raise NotImplementedError('Unknown result_code "{}"'.format(result_code))

        selectedImage = intent.getData();  # Uri
        filePathColumn = [MediaStore_Images_Media_DATA]; # String[]
        # Cursor
        cursor = currentActivity.getContentResolver().query(selectedImage,
                filePathColumn, None, None, None);
        cursor.moveToFirst();

        # int
        columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        # String
        picturePath = cursor.getString(columnIndex);
        cursor.close();
        Logger.info('android_ui: user_select_image() selected %s', picturePath)

        # This is possibly in a different thread?
        Clock.schedule_once(lambda dt: callback(picturePath), 0)

    # See: http://pyjnius.readthedocs.org/en/latest/android.html
    activity.bind(on_activity_result=on_activity_result)

    intent = Intent()

    # http://programmerguru.com/android-tutorial/how-to-pick-image-from-gallery/
    # http://stackoverflow.com/questions/18416122/open-gallery-app-in-android
    intent.setAction(Intent.ACTION_PICK)
    # TODO internal vs external?
    intent.setData(Uri.parse('content://media/internal/images/media'))
    # TODO setType(Image)?

    currentActivity.startActivityForResult(intent, RESULT_LOAD_IMAGE)

[tito]

Good point, i've no idea either where it should go. Maybe python-for-android in the examples sections. Check the docs/ directory :)

[btatlisu]

please delete me from thıs group
19:07, 6 декабря 2015 пользователь Alexander Taylor notifications@github.com написал:

    Closed #388.

    —Reply to this email directly or view it on GitHub.

[inclement]

@btatlisu I don't think we can do anything, fix your github notification settings.

[mnural]

This example is wonderful and instructive
I think it should be in the /docs directory or kivy examples package.
Nice tutorial @arlowhite thanks.

[kamathln]

Just a doubt. Can this go into the Garden As well ?

[aqulline]

ok I have read it but I really don't know how and where to use it like can someone show me a working example pls because i am stuck here

[arlowhite]

this is 5 years old, I no longer do Kivy development. good luck

[ZXTube]

This was probably introduced in a new android API that didn't exist 5 years ago but when I tried to set the source of an image to the path of the image the user picked I got this error: Error loading </storage/emulated/0/DCIM/Camera/IMG_20220824_235832.jpg>

Even when I had READ_EXTERNAL_STORAGE in the permissions in buildozer.spec

And I had to do this to stop the error:

from android.permissions import request_permissions, Permission
request_permissions([Permission.READ_EXTERNAL_STORAGE], callback) # The callback is optional so you can remove it 

def callback(permissions, results):
    print(permissions) # The permissions you requested e.g. [android.permissions.Permission.READ_EXTERNAL_STORAGE, android.per]   etc.
    print(results) # A boolean list of the accepted and rejected permissions e.g. [true, true, false, true] etc.