Android

The SDK for Android embeds the widget in your app and reports the condition of the challenge with a listener.

Requirements

The following requirements are met:

Requirement	Value
Android	From version 4.1 Jelly Bean, API level 16
Language	Kotlin or Java. The SDK is written in Kotlin.
Credentials	Public sitekey from the Details view

Embed the SDK

Add these entries to the build.gradle file:

repositories {
    mavenCentral()
}

dependencies {
    implementation "eu.eucaptcha.android:eu-captcha-android:1.0.0"
    // Or for `build.gradle.kts`
    // implementation("eu.eucaptcha.android:eu-captcha-android:1.0.0")
}

Make the widget

Make the SDK and the widget in your activity:

import eu.eucaptcha.android.sdk.*

const val EU_CAPTCHA_SITEKEY = "EUCAPTCHA_SITE_KEY"

class MainActivity : ComponentActivity() {
    private val sdk by lazy {
        EuCaptchaSDK(context = this)
    }

    private val widget by lazy {
        sdk.createWidget(sitekey = EU_CAPTCHA_SITEKEY)
    }
}

The optional theme parameter takes the values "light" and "dark". Without a value, the widget follows the light or dark mode of the device.

Show the widget

Show the widget in your interface and read the condition:

val captchaResponse = remember { mutableStateOf("") }
var buttonEnabled by remember { mutableStateOf(false) }

widget.setOnStateChangeListener { event ->
    captchaResponse.value = event.response
    when (event.state) {
        "completed" -> buttonEnabled = true
        "expired"   -> buttonEnabled = false
        "error"     -> buttonEnabled = true
    }
}

AndroidView(factory = { _ -> widget.view })

Button(onClick = { widget.reset() }, enabled = buttonEnabled) {
    Text("Submit")
}

The listener reports these conditions:

Condition	Meaning
completed	The challenge passed. The response field contains the token.
expired	The token expired.
error	An error occurred during the verification.
destroyed	The widget was removed with widget.destroy().

For single events, the setOnCompleteListener, setOnErrorListener, and setOnExpireListener receivers are also available.

The widget.reset() call starts a new challenge. As long as the widget is not loaded, the call has no effect.

The widget.destroy() call hides the widget and releases the resources. After this, the widget reports no more conditions.

Verify the token

Send the token to your server and verify it there. See Verify a client token.