Remove suitability check for calling object after permission result callback

[jmarkovic]

With the current implementation, EasyPermissions library assumes the calling object (actually, the object provided in EasyPermissions.onRequestPermissionsResultmethod) is of type Activity or Fragment. While the assumption may be valid, it can be beneficial for the user to forward the response to another component that is not an Activity nor a Fragment.

This PR removes the call to EasyPermissions#checkCallingObjectSuitability(Object object); from onRequestPermissionsResult. I have not noticed the need to perform this check at this callback method since the object is never cast to Activity. With this, any object can be provided as long as it either has a method with AfterPermissionGranted annotation or it implements PermissionCallbacks interface.

There's also a question - is there a plan for a feature/fix that would require this object to be an Activity inside this method? I fail to see a good reason for that.

Usecase

I've put a very trivial example of how this could be used. There's a new class called FeatureComponent which requires a permission to run some logic. Traditionally, this is communicated to the Activity of Fragment. With EasyPermissions, this isn't required, except the permission callback receiver must be an Activity which would then forward all events back to the component. With this check removed, this is no longer required - component itself can take these callbacks.

A few issues I've noticed

With this approach, the object which calls the request for permissions still has to override onRequestPermissionsResult, which isn't surprising. But, instead of specifying this, it has to provide the exact component which expects the result. For example:

EasyPermissions.onRequestPermissionsResult(
  requestCode,
  permissions,
  grantResults,
  featureComponent // this component should get the result
);

Example app also shows that the call to EasyPermissions.onRequestPermissionsResult must be repeated with different objects supplied. Example is below:

        EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);
        // Example when the {@code object} instance is not an Activity or Fragment.
        // Consider making object a vararg parameter.
        EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, featureComponent);

While this isn't really an issue in this example, having more than two components might not be pretty. Could we consider having a vararg parameter for objects instead?

Another issue - when a component implements PermissionCallbacks, they need to implement a method from ActivityCompat.OnRequestPermissionsResultCallback. Is this extension really needed for this interface? I've checked, its method is never called in the library.

[samtstern]

I am open to allowing objects not in the [Activity, Fragment] set to receive the callbacks, but I share your concern about the repeated onRequestPermissionResult calls looking ugly and being a little hard to maintain.

Do you have any alternative way to achieve this without complicating the API surface? After all it is called easy permissions and this is a somewhat advanced use case.

[jmarkovic]

You reflected my concern to the point - what makes it easy but not complicated? When thinking about it, I believe making the object a vararg parameter would be the most beneficial while not breaking much (or anything).

I could make an edit to this PR in order to create an example, if that's OK with you.

As a side question, do you have a roadmap or any rough plans with this lib? It might be beneficial for you and the lib to create some ground rules over which we can discuss further development.

[jmarkovic]

I took the liberty to create an example of what I meant. The following changes are relevant:

• onRequestPermissionResult method in EasyPermissions class now accepts a vararg parameter of Objects
• MainActivity now has a single line example of how to use the method mentioned above.

EasyPermissions.onRequestPermissionsResult(
  requestCode,
  permissions,
  grantResults,
  activity, fragment, featureComponent // vararg
)

It looks really simple and it does not break any existing usage. I do hope it does not clash with some of your plans.

[samtstern]

Can we revert this back? EasyPermissions has some outstanding issues with 2.14.1

[samtstern]

@jmarkovic with the varargs param this looks much better! I am happy to merge it, given my comments above. Let's just delete the sample pieces and then this is good to go.

[samtstern]

Awesome! Thanks for sticking through this. I am going to use the 'squash and merge' option here to make the 6 commits into one, so you may have to update your fork.

[jmarkovic]

@samtstern I believe I reverted everything you asked me. It might be wise for you to squash this.
Please notify me if there are any more issues.

[samtstern]

@jmarkovic you read my mind, thanks again!

[jmarkovic]

No problem. I find this lib very useful so I plan to stick with it for quite some time :)