Kotlin Android Studio - Var is seen as val in SDK 29

Question

I'm experiencing a pretty strange thing in Kotlin. I have

var myClipboard = getSystemService(CLIPBOARD_SERVICE) as ClipboardManager?
var myClip: ClipData? = ClipData.newPlainText( /* my code */ )

As a var variable, I should be able to reassign his value, but when I do

myClipboard?.primaryClip = myClip

It gives me the error

Val cannot be reassigned

The strangest things is that I'm using this code by weeks and it always worked. It stopped working today when I updated to API 29

This is my build.gradle android{}

    android {
    compileSdkVersion 29
    defaultConfig {
        applicationId "com.arfmann.pushnotes"
        minSdkVersion 23
        targetSdkVersion 29
        versionCode 16
        versionName "1.6"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

`myClip` is a `var`, `myClipboard` is a `var`. You are trying to set `myClipboard?.primaryClip`, which is neither of those. Still, your syntax should work. Try switching it to `myClipboard?.setPrimaryClip()` and see what you get. — CommonsWare, Jul 20 '19 at 21:32
The error is referring to `primaryClip` and not `myClipboard`. — forpas, Jul 20 '19 at 21:33

ianhanniballake · Accepted Answer · 2019-07-20T22:12:41.787

39

As seen in the ClipboardManager documentation, getPrimaryClip returns a ClipData? (i.e., a nullable ClipData) while setPrimaryClip() takes a ClipData - a non-null ClipData.

Kotlin does not support var property access when the types are different (and nullability is an important part of Kotlin typing) therefore Kotlin can only give you effectively the val equivalent when you call primaryClip.

The nullability annotation on setPrimaryClip was added in API 29, which is why the behavior is different once you upgrade your compileSdkVersion.

To set the primary clip, you must explicitly use setPrimaryClip() with a non-null ClipData or, on API 28+, use clearPrimaryClip() to completely clear the primary clip.

edited Jul 20 '19 at 22:12

answered Jul 20 '19 at 22:05

ianhanniballake

191,609
30
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hi @ianhannibalake, I have tried but still not working will you please help me https://stackoverflow.com/questions/61359729/val-can-not-be-reassigned-at-clipboardmanager-primaryclip – Siddhpura Amit Apr 22 '20 at 07:46
This helped a lot! Thanks. – waseefakhtar Sep 01 '20 at 14:41

score 10 · Answer 2 · answered Jun 29 '20 at 13:46

10

Use it like this

val clipboard = ctx.getSystemService(CLIPBOARD_SERVICE) as ClipboardManager
val clip = ClipData.newPlainText("Beacon infos", it.toJson())
clipboard.setPrimaryClip(clip)

answered Jun 29 '20 at 13:46

Saurabh Yadav

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1
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score 0 · Answer 3 · answered Jul 21 '19 at 03:13

0

Here is the working copy,

    val myClipboard = getSystemService(CLIPBOARD_SERVICE) as ClipboardManager?
    val myClip: ClipData? = ClipData.newPlainText("", "")

    myClipboard?.primaryClip = myClip

Hope this can help you

answered Jul 21 '19 at 03:13

Suresh Maidaragi

2,173
18
25

Kotlin Android Studio - Var is seen as val in SDK 29

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