[android] OfflineManager#setResourceTransform to allow transforming URLs prior to internet requests

1 files changed, 32 insertions, 0 deletions

diff --git a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/offline/OfflineManager.java b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/offline/OfflineManager.java
index d2371fcc2f..09acda792c 100644
--- a/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/offline/OfflineManager.java
+++ b/platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/offline/OfflineManager.java
@@ -10,6 +10,7 @@ import android.support.annotation.NonNull;
 
 import com.mapbox.mapboxsdk.Mapbox;
 import com.mapbox.mapboxsdk.constants.MapboxConstants;
+import com.mapbox.mapboxsdk.storage.Resource;
 
 import java.io.File;
 
@@ -81,6 +82,22 @@ public class OfflineManager {
     void onError(String error);
   }
 
+  /**
+   * This callback allows implementors to transform URLs before they are requested
+   * from the internet. This can be used add or remove custom parameters, or reroute
+   * certain requests to other servers or endpoints.
+   */
+  public interface ResourceTransformCallback {
+    /**
+     * Called whenever a URL needs to be transformed.
+     *
+     * @param kind The kind of URL to be transformed.
+     * @param offlineRegions The original URL to be transformed.
+     * @return A URL that will now be downloaded.
+     */
+    String onURL(@Resource.Kind int kind, String url);
+  }
+
   /*
    * Constructors
    */
@@ -265,6 +282,18 @@ public class OfflineManager {
     });
   }
 
+  /**
+   * Sets a callback for transforming URLs requested from the internet
+   * <p>
+   * The callback will be executed on the main thread once for every requested URL.
+   * </p>
+   *
+   * @param callback the callback to be invoked
+   */
+  public void setResourceTransform(@NonNull final ResourceTransformCallback callback) {
+    setResourceTransform(mDefaultFileSourcePtr, callback);
+  }
+
   /*
   * Changing or bypassing this limit without permission from Mapbox is prohibited
   * by the Mapbox Terms of Service.
@@ -291,6 +320,9 @@ public class OfflineManager {
     long defaultFileSourcePtr, OfflineRegionDefinition definition,
     byte[] metadata, CreateOfflineRegionCallback callback);
 
+  private native void setResourceTransform(
+    long defaultFileSourcePtr, ResourceTransformCallback callback);
+
   private native void setOfflineMapboxTileCountLimit(
     long defaultFileSourcePtr, long limit);