Refactor SettingsProvider methods to properties

- Change `appInForeground()` to `appInForeground` property
- Change `trustSystemCerts()` to `trustSystemCerts` property
- Update usages in CustomCertManager and MainActivity

Author: rfc2822

lib/src/main/java/at/bitfire/cert4android/CustomCertManager.kt

@@ -50,8 +50,8 @@ class CustomCertManager @JvmOverloads constructor(
         if (!certStore.isTrusted(
                 chain,
                 authType,
-                trustSystemCerts = settings.trustSystemCerts(),
-                appInForeground = settings.appInForeground()
+                trustSystemCerts = settings.trustSystemCerts,
+                appInForeground = settings.appInForeground
             )
         )
             throw CertificateException("Certificate chain not trusted")
@@ -81,7 +81,7 @@ class CustomCertManager @JvmOverloads constructor(
                         arrayOf(cert),
                         "RSA",
                         trustSystemCerts = false,
-                        appInForeground = settings.appInForeground()
+                        appInForeground = settings.appInForeground
                     )
                 )
                     return true

lib/src/main/java/at/bitfire/cert4android/SettingsProvider.kt

@@ -11,27 +11,27 @@
 package at.bitfire.cert4android
 
 /**
- * Provides settings for cert4android.
+ * Provides settings for cert4android. Implementations can override the getters.
  *
  * Usually implemented by the app which uses cert4android, and then passed to cert4android classes
  * which need it.
  */
 interface SettingsProvider {
 
     /**
-     * Returns the app foreground status:
+     * The app foreground status:
      *
      * - `true`: foreground – directly launch UI ([TrustCertificateActivity]) and show notification (if possible)
      * - `false`: background – only show notification (if possible)
      * - `null`: non-interactive mode – don't show notification or launch activity
      */
-    fun appInForeground(): Boolean?
+    val appInForeground: Boolean?
 
     /**
-     * Returns whether system certificates shall be trusted.
+     * Whether system certificates shall be trusted.
      *
      * @return `true` if system certificates are considered trustworthy, `false` otherwise
      */
-    fun trustSystemCerts(): Boolean
+    val trustSystemCerts: Boolean
 
 }

sample-app/src/main/java/at/bitfire/cert4android/demo/MainActivity.kt

@@ -1,3 +1,13 @@
+/*
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ */
+
 package at.bitfire.cert4android.demo
 
 import android.Manifest
@@ -33,6 +43,7 @@ import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.viewModelScope
 import at.bitfire.cert4android.CustomCertManager
 import at.bitfire.cert4android.CustomCertStore
+import at.bitfire.cert4android.SettingsProvider
 import at.bitfire.cert4android.ThemeManager
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -62,7 +73,7 @@ class MainActivity : ComponentActivity() {
                     .padding(8.dp)
                     .verticalScroll(rememberScrollState())) {
                     Row {
-                        Checkbox(model.appInForeground.collectAsState().value, onCheckedChange = { foreground ->
+                        Checkbox(model.foreground.collectAsState().value, onCheckedChange = { foreground ->
                             model.setInForeground(foreground)
                         })
                         Text("App in foreground")
@@ -131,7 +142,8 @@ class MainActivity : ComponentActivity() {
         val context: Context
             get() = getApplication()
 
-        val appInForeground = MutableStateFlow(true)
+        val foreground = MutableStateFlow(true)
+
         val resultMessage = MutableLiveData<String>()
 
         init {
@@ -145,7 +157,7 @@ class MainActivity : ComponentActivity() {
         }
 
         fun setInForeground(foreground: Boolean) {
-            appInForeground.value = foreground
+            this.foreground.value = foreground
         }
 
         fun testAccess(url: String, trustSystemCerts: Boolean = true) = viewModelScope.launch(Dispatchers.IO) {
@@ -177,8 +189,12 @@ class MainActivity : ComponentActivity() {
             // set cert4android TrustManager and HostnameVerifier
             val certManager = CustomCertManager(
                 certStore = CustomCertStore.getInstance(context),
-                trustSystemCerts = trustSystemCerts,
-                appInForeground = appInForeground
+                settings = object : SettingsProvider {
+                    override val appInForeground
+                        get() = foreground.value
+                    override val trustSystemCerts
+                        get() = trustSystemCerts
+                }
             )
 
             val sslContext = SSLContext.getInstance("TLS")