[SDK-500] Follow the system light/dark theme in HTML in-app messages

CHANGELOG.md

@@ -5,8 +5,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 ## [Unreleased]
 ### Added
 - `IterableConfig.Builder.setExpiringAuthTokenRefreshPeriod(double)` accepts fractional seconds, matching the iOS, React Native and Flutter SDKs. Previously Android only accepted whole seconds, so a value like `0.5` behaved differently here than on other platforms. The existing `Long` overload is deprecated but still works, so no code changes are required.
+- Added `IterableConfig.Builder.setInAppColorScheme()` and `setInAppColorSchemeProvider()` to control the color scheme reported to HTML in-app messages. The provider is evaluated for each new in-app message, allowing apps that keep their theme in Jetpack Compose state to return the current `LIGHT` or `DARK` scheme.
 
 ### Fixed
+- HTML in-app messages now follow the host activity's Android light-dark configuration instead of always rendering as if the device were in dark mode. Previously the in-app container always reported `prefers-color-scheme: dark` to the message HTML, so a campaign with an `@media (prefers-color-scheme: dark)` block rendered its dark styles even in light mode. Those campaigns now render their light styles in light mode; campaigns that don't declare dark styles, and rendering in dark mode, are unaffected.
 - Fixed the keychain treating a transient crypto timeout as a permanent decryption failure. A slow AndroidKeyStore operation that exceeded the 500 ms timeout would wipe the stored email, userId, and auth token and disable encryption, forcing the user to re-authenticate (and request a new auth token) on the next launch. Crypto timeouts are now handled as transient without wiping credentials or disabling encryption for the device: a read that times out returns no value for that call (the stored ciphertext is left intact for the next attempt), and a write that times out stores that one value unencrypted (as the non-encrypted fallback already did) rather than clearing everything. The timed-out crypto operation is also cancelled so it no longer blocks subsequent reads/writes.
 - `setExpiringAuthTokenRefreshPeriod` now validates its input instead of silently producing a broken refresh schedule. Previously a negative value was converted to a negative millisecond period and then *subtracted* when computing the refresh time, scheduling the refresh after the token had already expired; a very large value overflowed to a negative period with the same effect; and `null` threw a `NullPointerException` on unboxing. Invalid values (`null`, `NaN`, negatives) are now logged and ignored, leaving the period at whatever it was before the call — the 60 second default unless an earlier call set something else. Values above ~10 years are clamped to that ceiling rather than ignored. Zero remains valid and means the token is refreshed only once it has expired.
 - Fixed a `NullPointerException` in `EmbeddedSessionManager.updateDisplayCountAndDuration()` that could crash apps calling embedded session methods off the main thread. `EmbeddedSessionManager` is now internally synchronized, which also fixes concurrent modification of its impression map and duplicate session tracking when `endSession()` raced with itself. Thanks to [@Shamyyoun](https://github.com/Shamyyoun) for the report and initial fix.

iterableapi/src/main/java/com/iterable/iterableapi/IterableConfig.java

@@ -156,6 +156,17 @@ public class IterableConfig {
      */
     final IterableInAppDisplayMode inAppDisplayMode;
 
+    /**
+     * Controls the color scheme reported to HTML in-app messages.
+     */
+    final IterableInAppColorScheme inAppColorScheme;
+
+    /**
+     * Supplies the current in-app color scheme when an in-app message is created.
+     */
+    @Nullable
+    final IterableInAppColorSchemeProvider inAppColorSchemeProvider;
+
     /**
      * Base URL for Webview content loading. Specifically used to enable CORS for external resources.
      * If null or empty, defaults to empty string (original behavior with about:blank origin).
@@ -200,6 +211,8 @@ private IterableConfig(Builder builder) {
         mobileFrameworkInfo = builder.mobileFrameworkInfo;
         webViewBaseUrl = builder.webViewBaseUrl;
         inAppDisplayMode = builder.inAppDisplayMode;
+        inAppColorScheme = builder.inAppColorScheme;
+        inAppColorSchemeProvider = builder.inAppColorSchemeProvider;
     }
 
     public static class Builder {
@@ -229,6 +242,8 @@ public static class Builder {
         private IterableUnknownUserHandler iterableUnknownUserHandler;
         private String webViewBaseUrl;
         private IterableInAppDisplayMode inAppDisplayMode = IterableInAppDisplayMode.FORCE_EDGE_TO_EDGE;
+        private IterableInAppColorScheme inAppColorScheme = IterableInAppColorScheme.AUTOMATIC;
+        private IterableInAppColorSchemeProvider inAppColorSchemeProvider;
 
         public Builder() {}
 
@@ -530,6 +545,36 @@ public Builder setInAppDisplayMode(@NonNull IterableInAppDisplayMode inAppDispla
             return this;
         }
 
+        /**
+         * Set the color scheme reported to HTML in-app messages. Defaults to
+         * {@link IterableInAppColorScheme#AUTOMATIC}, which follows the host activity's
+         * Android UI mode. Setting a fixed value clears any color scheme provider.
+         *
+         * @param inAppColorScheme the color scheme for HTML in-app messages
+         */
+        @NonNull
+        public Builder setInAppColorScheme(@NonNull IterableInAppColorScheme inAppColorScheme) {
+            this.inAppColorScheme = inAppColorScheme;
+            this.inAppColorSchemeProvider = null;
+            return this;
+        }
+
+        /**
+         * Set a provider that supplies the current color scheme whenever an HTML in-app
+         * message is created. Use this when the app's theme is held outside Android's
+         * configuration, such as theme state managed in Jetpack Compose. Setting a provider
+         * replaces any fixed color scheme.
+         *
+         * @param provider the provider for the current in-app color scheme
+         */
+        @NonNull
+        public Builder setInAppColorSchemeProvider(
+                @NonNull IterableInAppColorSchemeProvider provider) {
+            this.inAppColorScheme = IterableInAppColorScheme.AUTOMATIC;
+            this.inAppColorSchemeProvider = provider;
+            return this;
+        }
+
         /**
          * Set the base URL for WebView content loading. Used to enable CORS for external resources.
          * If not set or null, defaults to empty string (original behavior with about:blank origin).
@@ -548,4 +593,4 @@ public IterableConfig build() {
         }
     }
 
-}
+}

iterableapi/src/main/java/com/iterable/iterableapi/IterableInAppColorScheme.java

@@ -0,0 +1,21 @@
+package com.iterable.iterableapi;
+
+/**
+ * Controls the color scheme reported to HTML in-app messages.
+ */
+public enum IterableInAppColorScheme {
+    /**
+     * Follow the host activity's Android UI mode.
+     */
+    AUTOMATIC,
+
+    /**
+     * Report a light color scheme to in-app message HTML.
+     */
+    LIGHT,
+
+    /**
+     * Report a dark color scheme to in-app message HTML.
+     */
+    DARK
+}

iterableapi/src/main/java/com/iterable/iterableapi/IterableInAppColorSchemeProvider.java

@@ -0,0 +1,17 @@
+package com.iterable.iterableapi;
+
+import androidx.annotation.NonNull;
+
+/**
+ * Supplies the color scheme to use when an HTML in-app message is created.
+ */
+@FunctionalInterface
+public interface IterableInAppColorSchemeProvider {
+    /**
+     * Returns the current color scheme for HTML in-app messages.
+     *
+     * @return the color scheme to use
+     */
+    @NonNull
+    IterableInAppColorScheme getInAppColorScheme();
+}

iterableapi/src/main/java/com/iterable/iterableapi/IterableInAppColorSchemeResolver.java

@@ -0,0 +1,60 @@
+package com.iterable.iterableapi;
+
+import androidx.annotation.NonNull;
+
+final class IterableInAppColorSchemeResolver {
+    private static final String TAG = "IterableInAppColorScheme";
+
+    private IterableInAppColorSchemeResolver() {
+    }
+
+    @NonNull
+    static IterableInAppColorScheme resolve() {
+        IterableConfig config = IterableApi.sharedInstance == null
+                ? null
+                : IterableApi.sharedInstance.config;
+        if (config == null) {
+            return IterableInAppColorScheme.AUTOMATIC;
+        }
+
+        IterableInAppColorSchemeProvider provider = config.inAppColorSchemeProvider;
+        if (provider == null) {
+            return config.inAppColorScheme;
+        }
+
+        try {
+            IterableInAppColorScheme colorScheme = provider.getInAppColorScheme();
+            if (colorScheme != null) {
+                return colorScheme;
+            }
+            IterableLogger.e(TAG, "Color scheme provider returned null; using AUTOMATIC");
+        } catch (Exception e) {
+            IterableLogger.e(TAG, "Color scheme provider failed; using AUTOMATIC", e);
+        }
+        return IterableInAppColorScheme.AUTOMATIC;
+    }
+
+    static int resolveDialogTheme() {
+        switch (resolve()) {
+            case LIGHT:
+                return R.style.Iterable_InAppDialog_Light;
+            case DARK:
+                return R.style.Iterable_InAppDialog_Dark;
+            case AUTOMATIC:
+            default:
+                return R.style.Iterable_InAppDialog;
+        }
+    }
+
+    static int resolveFragmentTheme() {
+        switch (resolve()) {
+            case LIGHT:
+                return R.style.Iterable_InAppFragment_Light;
+            case DARK:
+                return R.style.Iterable_InAppFragment_Dark;
+            case AUTOMATIC:
+            default:
+                return R.style.Iterable_InAppFragment;
+        }
+    }
+}

iterableapi/src/main/java/com/iterable/iterableapi/IterableInAppDialogNotification.kt

@@ -47,7 +47,10 @@ class IterableInAppDialogNotification internal constructor(
     private val webViewService: InAppWebViewService = InAppServices.webView,
     private val orientationService: InAppOrientationService = InAppServices.orientation,
     private val displayModeService: InAppDisplayModeService = InAppServices.displayMode
-) : Dialog(hostActivity, R.style.Iterable_InAppDialog), IterableWebView.HTMLNotificationCallbacks {
+) : Dialog(
+    hostActivity,
+    IterableInAppColorSchemeResolver.resolveDialogTheme()
+), IterableWebView.HTMLNotificationCallbacks {
 
     private var webView: IterableWebView? = null
     private var loaded: Boolean = false
@@ -522,4 +525,3 @@ class IterableInAppDialogNotification internal constructor(
         trackingService.removeMessage(message)
     }
 }
-

iterableapi/src/main/java/com/iterable/iterableapi/IterableInAppFragmentHTMLNotification.java

@@ -123,7 +123,9 @@
         this.backgroundAlpha = 0;
         this.messageId = "";
         insetPadding = new Rect();
-        this.setStyle(DialogFragment.STYLE_NO_FRAME, androidx.appcompat.R.style.Theme_AppCompat_NoActionBar);
+        this.setStyle(
+                DialogFragment.STYLE_NO_FRAME,
+                IterableInAppColorSchemeResolver.resolveFragmentTheme());
     }
 
     @Override
@@ -210,7 +212,9 @@
             return null;
         }
 
-        webView = createWebViewSafely(getContext());
+        // The WebView derives the CSS prefers-color-scheme value from its context theme's
+        // isLightTheme, so it needs the dialog's themed context and not the host activity's.
+        webView = createWebViewSafely(getDialog().getContext());
         if (webView == null) {
             dismissAllowingStateLoss();
             return null;

iterableapi/src/main/res/values-v29/styles.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+    <style name="Iterable.InAppDialog.Light">
+        <item name="android:isLightTheme">true</item>
+    </style>
+
+    <style name="Iterable.InAppDialog.Dark">
+        <item name="android:isLightTheme">false</item>
+    </style>
+
+    <style name="Iterable.InAppFragment.Light">
+        <item name="android:isLightTheme">true</item>
+    </style>
+
+    <style name="Iterable.InAppFragment.Dark">
+        <item name="android:isLightTheme">false</item>
+    </style>
+</resources>

iterableapi/src/main/res/values/styles.xml

@@ -11,13 +11,15 @@
     </style>
 
     <!-- Theme for IterableInAppDialogNotification. Mirrors the DialogFragment-side
-         STYLE_NO_FRAME + Theme_AppCompat_NoActionBar combination. windowIsFloating stays
-         true (the Dialog default) so the host activity's status/navigation bars remain
-         visible — RESPECT_BOUNDS depends on this. windowMinWidth*=100% overrides the
-         floating-dialog small-card sizing so the in-app can fill the activity content
-         area when it wants to. Modes that need to cover the bars (FORCE_FULLSCREEN,
-         FORCE_EDGE_TO_EDGE) add FLAG_LAYOUT_NO_LIMITS explicitly at runtime. -->
-    <style name="Iterable.InAppDialog" parent="Theme.AppCompat.NoActionBar">
+         STYLE_NO_FRAME + Theme_AppCompat_DayNight_NoActionBar combination. The DayNight
+         parent is what lets the WebView report the right prefers-color-scheme to the
+         in-app HTML. windowIsFloating stays true (the Dialog default) so the host
+         activity's status/navigation bars remain visible — RESPECT_BOUNDS depends on
+         this. windowMinWidth*=100% overrides the floating-dialog small-card sizing so
+         the in-app can fill the activity content area when it wants to. Modes that need
+         to cover the bars (FORCE_FULLSCREEN, FORCE_EDGE_TO_EDGE) add
+         FLAG_LAYOUT_NO_LIMITS explicitly at runtime. -->
+    <style name="Iterable.InAppDialog" parent="Theme.AppCompat.DayNight.NoActionBar">
         <item name="android:windowBackground">@android:color/transparent</item>
         <item name="android:windowContentOverlay">@null</item>
         <item name="android:windowNoTitle">true</item>
@@ -27,4 +29,14 @@
         <item name="android:windowMinWidthMajor">100%</item>
         <item name="android:windowMinWidthMinor">100%</item>
     </style>
-</resources>
+
+    <style name="Iterable.InAppDialog.Light" />
+
+    <style name="Iterable.InAppDialog.Dark" />
+
+    <style name="Iterable.InAppFragment" parent="Theme.AppCompat.DayNight.NoActionBar" />
+
+    <style name="Iterable.InAppFragment.Light" />
+
+    <style name="Iterable.InAppFragment.Dark" />
+</resources>

iterableapi/src/test/java/com/iterable/iterableapi/IterableConfigTest.kt

@@ -36,6 +36,37 @@ class IterableConfigTest {
         val config: IterableConfig = configBuilder.build()
         assertThat(config.webViewBaseUrl, `is`("https://app.iterable.com"))
     }
+
+    @Test
+    fun defaultInAppColorSchemeIsAutomatic() {
+        val config = IterableConfig.Builder().build()
+
+        assertEquals(IterableInAppColorScheme.AUTOMATIC, config.inAppColorScheme)
+        assertNull(config.inAppColorSchemeProvider)
+    }
+
+    @Test
+    fun setInAppColorSchemeUsesFixedValue() {
+        val config = IterableConfig.Builder()
+            .setInAppColorSchemeProvider { IterableInAppColorScheme.LIGHT }
+            .setInAppColorScheme(IterableInAppColorScheme.DARK)
+            .build()
+
+        assertEquals(IterableInAppColorScheme.DARK, config.inAppColorScheme)
+        assertNull(config.inAppColorSchemeProvider)
+    }
+
+    @Test
+    fun setInAppColorSchemeProviderUsesProvider() {
+        val provider = IterableInAppColorSchemeProvider { IterableInAppColorScheme.DARK }
+        val config = IterableConfig.Builder()
+            .setInAppColorScheme(IterableInAppColorScheme.LIGHT)
+            .setInAppColorSchemeProvider(provider)
+            .build()
+
+        assertEquals(IterableInAppColorScheme.AUTOMATIC, config.inAppColorScheme)
+        assertSame(provider, config.inAppColorSchemeProvider)
+    }
 
     @Test
     fun defaultDisableKeychainEncryption() {