From 95a977e12e1a3163c2fca7dff4648555144e69f0 Mon Sep 17 00:00:00 2001
From: Bart Louwers <bart@emeel.net>
Date: Fri, 14 Aug 2026 16:37:28 +0200
Subject: [PATCH] Reduce Android AAR size with header-only Prefab (#4483)

---
 include/mbgl/style/layers/custom_layer_host.hpp   |  6 +++++-
 platform/android/MapLibreAndroid/build.gradle.kts | 12 +++++++++++-
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/include/mbgl/style/layers/custom_layer_host.hpp b/include/mbgl/style/layers/custom_layer_host.hpp
index 6561be1aa..4abe092a3 100644
--- a/include/mbgl/style/layers/custom_layer_host.hpp
+++ b/include/mbgl/style/layers/custom_layer_host.hpp
@@ -1,10 +1,14 @@
 #pragma once
 
-#include <mbgl/gfx/context.hpp>
 #include <mbgl/style/layers/custom_layer_init_parameters.hpp>
 #include <mbgl/style/layers/custom_layer_render_parameters.hpp>
 
 namespace mbgl {
+
+namespace gfx {
+class Context;
+} // namespace gfx
+
 namespace style {
 
 class CustomLayerHost {
diff --git a/platform/android/MapLibreAndroid/build.gradle.kts b/platform/android/MapLibreAndroid/build.gradle.kts
index 5a645ac39..eef6ee1d1 100644
--- a/platform/android/MapLibreAndroid/build.gradle.kts
+++ b/platform/android/MapLibreAndroid/build.gradle.kts
@@ -204,7 +204,7 @@ android {
     prefab {
         create("maplibre") {
             headers = "../prefab-headers"
-            libraryName = "libmaplibre"
+            headerOnly = true
         }
     }
 
@@ -240,6 +240,16 @@ tasks.configureEach {
     }
 }
 
+// AGP 9.1.1 still adds the native build output to the AAR even when the Prefab module is
+// declared header-only. Keep the header-only metadata and omit that redundant unstripped copy.
+tasks.withType<org.gradle.api.tasks.bundling.Zip>().configureEach {
+    if (name.startsWith("bundle") && name.endsWith("Aar")) {
+        // The Prefab artifact is added under a `prefab/` destination by a nested copy spec,
+        // so its paths are still relative to the Prefab root when exclusions are evaluated.
+        exclude("modules/maplibre/libs/**")
+    }
+}
+
 configurations {
     getByName("implementation") {
         exclude(group = "commons-logging", module = "commons-logging")