Kotlin as a language is comfy though, barring the ...

# android

[Gavin Ray]

Kotlin as a language is comfy though, barring the Android bit.

[Mikael Alfredsson]

Moving to a thread since you have a big question.
I think you have over-engineered the dialog popup, but I don’t know all requirements so im not sure.

[Mikael Alfredsson]

you can inherit from DialogFragment and just open it as a normal fragment instead of dealing with “window” objects directly.

[Gavin Ray]

I didn't engineer any of this at all, which is part of the problem (I have never even done Android development before). This app was outsourced to foreign developers before I came on to the company =/

[Gavin Ray]

Sorry for the long series of texts, I should have definitely put it in a thread on the first comment, my mistake.

[Mikael Alfredsson]

so you basically just want to add a new button opening the same dialog as you can open from another page as well?

[Gavin Ray]

Yeah, if you see the image, that pop-up screen on the bottom of the two screens is currently triggered from the join button on the left screen.

I just need to trigger that from the new floating Join button on the right screen

[Mikael Alfredsson]

where does the joinGameButton() function live? (in which class)

[Gavin Ray]

The function to trigger it is coded as a private method into GameFragment though. I tried making it public, doing val gameFragment = GameFragment.newInstance() inside of DetailFragment and then gameFragment.joinGamePopup() but it breaks because of Dialog(context) inside of the joinGamePopup() method in GameFragment

[Gavin Ray]

where does the joinGameButton() function live? (in which class) 

GameFragment

[Mikael Alfredsson]

does it use alot of other data from GameFragment, or could you extract it to a new class?

[Mikael Alfredsson]

context is easy to pass in as an argument to the new class, but do you need anything else?

[Mikael Alfredsson]

let me explain the problem. a fragment doesn’t actually have a context, the context is the activity that the fragment is attached to, so if you just create a new instance of a fragment and then try to get the context, you will get null

[Gavin Ray]

So the arguments that it takes are an instance of JoinGameModel, which has some information about the game the player is trying to join, and position, which after several hours I figured out is a magic variable that gets passed into fragments denoting their index.

I was able to recreate the JoinGameModel instance because it gets gameData from the parent fragment (GameFragment), and I tried hardcoding `0`/`1` as the position to try to trigger it on the first or second fragment.

[Mikael Alfredsson]

so if you can extract the function to its own class, make sure that you pass JoinGameModel in as a parameter (from either screen that opens this dialog) and context as a second parameter, this should work nicely

[Gavin Ray]

It looks like Dialog(context) is where most of the stuff happens in that method. This seems to create the pop-up window and populate it with info.

So assuming I can have the right context value in there, it should work right?

[Gavin Ray]

Yeah but what is context

[Gavin Ray]

class GamesFragment: Fragment(), SwipeRefreshLayout.OnRefreshListener{

    var context: MainActivity? = null

[Gavin Ray]

private fun joinGamePopup(gameJoin: JoinGameModel,position:Int) {
            val dialog = Dialog(context)

[Gavin Ray]

2020-03-11 13:22:50.418 26091-26091/com.plei.dev E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.plei.dev, PID: 26091
    java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources$Theme android.content.Context.getTheme()' on a null object reference
        at android.app.Dialog.<init>(Dialog.java:175)
        at android.app.Dialog.<init>(Dialog.java:149)
        at com.plei.screens.games.fragment.GamesFragment.joinGamePopup(GamesFragment.kt:246)
        at com.plei.screens.games.fragment.DetailFragment$_initialize$1.onClick(DetailFragment.kt:92)

[Mikael Alfredsson]

context is and object in android that holds more or less all important stuff. It tells you the current theme, language, resourcefile pointers, screen measurements and what not.
Application, Activity and Services has contexts (with minor differences) but fragments doesn’t so they have to get teh context form the outside (e.g Activity)

[Mikael Alfredsson]

joinGamePopup(context:Context, gameJoin: JoinGameModel,position:Int)

[Gavin Ray]

So I need to figure out how to get the context from the parent GameFragment into the DetailFragment function here to pass into context?

[Mikael Alfredsson]

no, you should not try to pass contexts between fragments yourself. the OS will make sure you have a context in your fragment when its showing on the screen

[Mikael Alfredsson]

refactor the method to take context as a parameter and move it to a separate class so you don’t have to instantiate GameFragment for this

[Mikael Alfredsson]

(normally people use a DialogFragment instead which handles basically everything you have in line 2 to 18)

[Gavin Ray]

Okay uhm, I can add the context as an argument but moving it to a separate class may very well be out of the scope of my abilities with 48 hours of Android/Kotlin experience.

[Mikael Alfredsson]

learning by doing.. I think it will be fine.

[Mikael Alfredsson]

just create a new kotlin class GamePopup or something

[Mikael Alfredsson]

move the popup function into that new class

[Mikael Alfredsson]

(not trying to make something nice right now, only getting it to work)

[Gavin Ray]

Screenshot from 2020-03-11 13-30-00.png

[Mikael Alfredsson]

you could also just copy the function into your other fragment as well, but that will be really ugly

[Gavin Ray]

Wait how is this even working if it says context is a type-mismatch?

[Gavin Ray]

but that will be really ugly

This whole codebase is... shudder

[Mikael Alfredsson]

it expects a non null variable and you are giving it a nullable variable

[Gavin Ray]

The dev used ID selectors to read values from text instead of data

[Mikael Alfredsson]

replace context with requireContext (runtime you will get the same exception. but the IDE might be happier)

[Mikael Alfredsson]

or context!

[Gavin Ray]

`

var context: MainActivity?

[Gavin Ray]

Replace MainActivity? with context!?

[Mikael Alfredsson]

no, but where you use it

[Mikael Alfredsson]

Activities are contexts so MainActivity can be casted to Context without any problem, but you have MainActivity? which can only be casted to Context? (notice the ?, aka nullable sign)

[Gavin Ray]

Ohhh

[Gavin Ray]

I didn't know Kotlin allowed types to be multiple things at once

[Mikael Alfredsson]

you have inheritance, so you can always just extend a base object, or/and you can add interfaces to a class allowing the class to be typecasted to any ancestor or interface type.

[Gavin Ray]

Okay so select the entire joinGamePopup and refactor it to a new class?

[Mikael Alfredsson]

Lets see if that is possible (depending on how many things it uses from the GameFragment) but yes, start with that

[Gavin Ray]

image.png

[Gavin Ray]

They really single-purposed this ;..;

[Mikael Alfredsson]

no problem, just continue 🙂

[Gavin Ray]

Okay its extracted

[Gavin Ray]

package com.plei.screens.games.fragment

import androidx.fragment.app.Fragment
import com.plei.models.JoinGameModel

open class GamesFragment1 : Fragment() {
    fun joinGamePopup(gameJoin: JoinGameModel, position: Int) {

[Mikael Alfredsson]

you should not have it in a fragment, just a class called GamePopup

[Mikael Alfredsson]

class GamePopup {
    fun joinGamePopup(gameJoin: JoinGameModel, position: Int) {

[Gavin Ray]

Which of the "refactor" options is that?

[Gavin Ray]

(also where should I put the class file?)

[Mikael Alfredsson]

oh, sorry, with refactor i just ment the act of refactoring, not any special IDE tricks.

[Gavin Ray]

Ohh kk

[Gavin Ray]

So just create a file called GamePopup.kt anywhere and paste that method in there

[Gavin Ray]

Put it in screens/games/fragment?

[Mikael Alfredsson]

yep, the placement of the file is less important

[Gavin Ray]

kk

[Gavin Ray]

Done 👌

[Mikael Alfredsson]

in your GameFragment you can now create a

val gamePopup = GamePopup()

[Mikael Alfredsson]

somewhere in the beginning (still not super solution, but easiest to explain 🙂 )

[Gavin Ray]

It's got a ton of un-resolved references

[Gavin Ray]

Because it calls other methods and imports from the fragment

[Mikael Alfredsson]

GameFragment or GamePopup?

[Gavin Ray]

GamePopup

[Mikael Alfredsson]

ok, yea, that is what i was afraid of. Imports are easy, the IDE will help you with that

[Mikael Alfredsson]

lets see which methods it complains about

[Gavin Ray]

Unresolved reference: paymentProcessPopup
Unresolved reference: Intent
Unresolved reference: startActivity
Unresolved reference: R
Unresolved reference: PaymentActivity
Unresolved reference: isPaymentAdded
Unresolved reference: joinGame
Unresolved reference: positiveButton
Unresolved reference: getButton
Unresolved reference: sharedPreference
Unresolved reference: AlertDialog
Unresolved reference: setBackgroundDrawable
Unresolved reference: Dialog
Unresolved reference: WindowManager

[Christophe Smet]

Just pay a senior Android dev to look at it ?

[Gavin Ray]

@Christophe Smet Lol no chance the business owners would pay money for that, but I eventually got it after 14 hours 👍

[Christophe Smet]

haha too bad, welcome to Kotlin and Android tho 😉