Add pagination to ListObjects()

Fixes #36

Add pagination support to ListObjects() method.

* Add a new overload for `ListObjectsAsync` in `IObjectService` interface to take a 'Cursor'-value and a max entries parameter.
* Update `ListObjectsOptions` class to include a `MaxEntries` property and update the `ToSWIG` method to include this property.
* Implement the new overload for `ListObjectsAsync` in `ObjectService` class to handle the 'Cursor'-value and max entries parameter.
* Update `BucketContentViewModel` class to use the new overload of `ListObjectsAsync` with 'Cursor'-value and max entries parameter.
* Add a new test method in `ObjectServiceTest` to verify the new overload of `ListObjectsAsync` with 'Cursor'-value and max entries parameter.

---

For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/TopperDEL/uplink.net/issues/36?shareId=XXXX-XXXX-XXXX-XXXX).

uplink.NET/uplink.NET.Sample/uplink.NET.Sample.Shared/ViewModels/BucketContentViewModel.cs

@@ -115,7 +115,7 @@ public async Task InitAsync()
             {
                 var bucket = await _bucketService.GetBucketAsync(BucketName);
                 var listOptions = new ListObjectsOptions();
-                var objects = await _objectService.ListObjectsAsync(bucket, listOptions);
+                var objects = await _objectService.ListObjectsAsync(bucket, listOptions, null, 1000);
                 foreach (var obj in objects.Items)
                 {
                     var entry = new BucketEntryViewModel(this, _bucketService, _objectService);

uplink.NET/uplink.NET.Test/ObjectServiceTest.cs

@@ -606,6 +606,36 @@ public async Task CopyObject_CopiesObject_InDifferentBucket()
             }
         }
 
+        [TestMethod]
+        public async Task ListObjects_WithCursorAndMaxEntries()
+        {
+            string bucketname = "listobject-with-cursor-maxentries";
+
+            await _bucketService.CreateBucketAsync(bucketname);
+            var bucket = await _bucketService.GetBucketAsync(bucketname);
+            byte[] bytesToUpload = GetRandomBytes(2048);
+
+            var uploadOperation1 = await _objectService.UploadObjectAsync(bucket, "myfile1.txt", new UploadOptions(), bytesToUpload, false);
+            await uploadOperation1.StartUploadAsync();
+            var uploadOperation2 = await _objectService.UploadObjectAsync(bucket, "myfile2.txt", new UploadOptions(), bytesToUpload, false);
+            await uploadOperation2.StartUploadAsync();
+            var uploadOperation3 = await _objectService.UploadObjectAsync(bucket, "myfile3.txt", new UploadOptions(), bytesToUpload, false);
+            await uploadOperation3.StartUploadAsync();
+
+            var listOptions = new ListObjectsOptions { MaxEntries = 2 };
+            var objectList = await _objectService.ListObjectsAsync(bucket, listOptions);
+
+            Assert.AreEqual(2, objectList.Items.Count);
+            Assert.AreEqual("myfile1.txt", objectList.Items[0].Key);
+            Assert.AreEqual("myfile2.txt", objectList.Items[1].Key);
+
+            listOptions.Cursor = objectList.Items[1].Key;
+            var objectList2 = await _objectService.ListObjectsAsync(bucket, listOptions);
+
+            Assert.AreEqual(1, objectList2.Items.Count);
+            Assert.AreEqual("myfile3.txt", objectList2.Items[0].Key);
+        }
+
         public static byte[] GetRandomBytes(long length)
         {
             byte[] bytes = new byte[length];
@@ -640,6 +670,7 @@ public async Task CleanupAsync()
             await DeleteBucketAsync("copyobject-copies-object-samebucket");
             await DeleteBucketAsync("copyobject-copies-object-diffbucket1");
             await DeleteBucketAsync("copyobject-copies-object-diffbucket2");            
+            await DeleteBucketAsync("listobject-with-cursor-maxentries");
         }
 
         private async Task DeleteBucketAsync(string bucketName)

uplink.NET/uplink.NET/Interfaces/IObjectService.cs

@@ -106,6 +106,15 @@ public interface IObjectService
         /// <returns>The list of found objects within the bucket and with the given ListOptions or throws an ObjectListException</returns>
         Task<ObjectList> ListObjectsAsync(Bucket bucket, ListObjectsOptions listObjectsOptions);
         /// <summary>
+        /// Lists objects within a bucket with pagination support
+        /// </summary>
+        /// <param name="bucket">The Bucket to list entries from</param>
+        /// <param name="listOptions">Options for the listing</param>
+        /// <param name="cursor">The cursor value to start listing from</param>
+        /// <param name="maxEntries">The maximum number of entries to return</param>
+        /// <returns>The list of found objects within the bucket and with the given ListOptions or throws an ObjectListException</returns>
+        Task<ObjectList> ListObjectsAsync(Bucket bucket, ListObjectsOptions listObjectsOptions, string cursor, int maxEntries);
+        /// <summary>
         /// Gets the specific object
         /// </summary>
         /// <param name="bucket">The Bucket where the object resides in</param>

uplink.NET/uplink.NET/Models/ListObjectsOptions.cs

@@ -29,6 +29,10 @@ public class ListObjectsOptions
         /// Custom includes CustomMetadata in the results.
         /// </summary>
         public bool Custom { get; set; }
+        /// <summary>
+        /// MaxEntries sets the maximum number of entries to return.
+        /// </summary>
+        public int MaxEntries { get; set; }
 
         internal SWIG.UplinkListObjectsOptions ToSWIG()
         {
@@ -38,6 +42,7 @@ internal SWIG.UplinkListObjectsOptions ToSWIG()
             ret.recursive = Recursive;
             ret.system = System;
             ret.custom = Custom;
+            ret.max_entries = MaxEntries;
 
             return ret;
         }

uplink.NET/uplink.NET/Services/ObjectService.cs

@@ -158,6 +158,13 @@ public async Task<ObjectList> ListObjectsAsync(Bucket bucket, ListObjectsOptions
             }
         }
 
+        public async Task<ObjectList> ListObjectsAsync(Bucket bucket, ListObjectsOptions listObjectsOptions, string cursor, int maxEntries)
+        {
+            listObjectsOptions.Cursor = cursor;
+            listObjectsOptions.MaxEntries = maxEntries;
+            return await ListObjectsAsync(bucket, listObjectsOptions).ConfigureAwait(false);
+        }
+
         public async Task<uplink.NET.Models.Object> GetObjectAsync(Bucket bucket, string targetPath)
         {
             using (var objectResult = await Task.Run(() => SWIG.storj_uplink.uplink_stat_object(_access._project, bucket.Name, targetPath)).ConfigureAwait(false))