feat(desktop): page and filter database nests on the server

The Database-mode Open dialog no longer downloads every record. It
browses through NestBrowseSession, which sends one bounded query per
change: the filter box (300 ms debounce) searches on the server and
returns to the first page, column headers sort every match on the
server (a second click reverses), and Previous/Next page by 100 with a
range and total in the status line. A response superseded by a newer
request is cancelled and discarded, refresh steps back when the current
page was emptied, and failures clear the rows and show the error
without a modal box per keystroke.

OpenNest.Data/NestBrowseSession.cs

@@ -0,0 +1,170 @@
+using System.Globalization;
+
+namespace OpenNest.Data;
+
+/// <summary>
+/// Browse state for the Database-mode Open dialog: the requested search, sort and page,
+/// and the last page applied. Every change issues one bounded server query. A response
+/// that a later request superseded is discarded (and the earlier request is cancelled),
+/// so an older result can never replace a newer one. Call from one thread (the UI thread).
+/// </summary>
+public sealed class NestBrowseSession : IDisposable
+{
+    private readonly INestRepository _repository;
+    private CancellationTokenSource? _pending;
+    private int _generation;
+    private bool _disposed;
+
+    public NestBrowseSession(INestRepository repository, int pageSize = NestQuery.DefaultLimit)
+    {
+        ArgumentNullException.ThrowIfNull(repository);
+        if (pageSize < 1 || pageSize > NestQuery.MaxLimit)
+            throw new ArgumentOutOfRangeException(nameof(pageSize), pageSize, $"Page size must be 1 to {NestQuery.MaxLimit}.");
+
+        _repository = repository;
+        PageSize = pageSize;
+    }
+
+    public int PageSize { get; }
+
+    /// <summary>Trimmed search text of the latest request.</summary>
+    public string Search { get; private set; } = "";
+
+    public NestSortField Sort { get; private set; } = NestSortField.SavedAt;
+
+    public bool Descending { get; private set; } = true;
+
+    /// <summary>Offset of the latest request.</summary>
+    public int Offset { get; private set; }
+
+    /// <summary>The latest applied page; null before the first result and after a failed request.</summary>
+    public NestPage? Page { get; private set; }
+
+    public bool CanGoPrevious => Offset > 0;
+
+    public bool CanGoNext => Page is { } page && page.Offset + page.Items.Count < page.Total;
+
+    /// <summary>Operator-facing summary of <see cref="Page"/>, such as "Showing 101-200 of 1,234 nests".</summary>
+    public string Summary
+    {
+        get
+        {
+            if (Page is not { } page)
+                return "";
+            if (page.Total == 0)
+                return Search.Length == 0 ? "No nests on the server." : "No nests match the filter.";
+            if (page.Items.Count == 0)
+                return $"No nests on this page ({Count(page.Total)} in total).";
+
+            return $"Showing {Count(page.Offset + 1)}-{Count(page.Offset + page.Items.Count)} of {Count(page.Total)} nests";
+        }
+    }
+
+    /// <summary>Applies new search text and returns to the first page.</summary>
+    public Task<bool> SetSearchAsync(string? search)
+    {
+        Search = (search ?? "").Trim();
+        Offset = 0;
+        return RunAsync();
+    }
+
+    /// <summary>Sorts by a column: a new column starts ascending, the same column reverses.</summary>
+    public Task<bool> SortByAsync(NestSortField field)
+    {
+        Descending = field == Sort && !Descending;
+        Sort = field;
+        Offset = 0;
+        return RunAsync();
+    }
+
+    public Task<bool> NextPageAsync()
+    {
+        if (!CanGoNext)
+            return Task.FromResult(false);
+
+        Offset = Page!.Offset + PageSize;
+        return RunAsync();
+    }
+
+    public Task<bool> PreviousPageAsync()
+    {
+        if (!CanGoPrevious)
+            return Task.FromResult(false);
+
+        Offset = System.Math.Max(0, Offset - PageSize);
+        return RunAsync();
+    }
+
+    /// <summary>Re-reads the current page; steps back to the last page if it is now past the end.</summary>
+    public Task<bool> RefreshAsync() => RunAsync();
+
+    /// <summary>
+    /// Sends the current request. Returns true when its page was applied, false when a later
+    /// request superseded it. Failures of the latest request clear <see cref="Page"/> and propagate;
+    /// failures of superseded requests are ignored.
+    /// </summary>
+    private async Task<bool> RunAsync()
+    {
+        ObjectDisposedException.ThrowIf(_disposed, this);
+        // Superseded sources are cancelled but not disposed: their request may still observe the token.
+        _pending?.Cancel();
+        var cancellation = new CancellationTokenSource();
+        _pending = cancellation;
+        var generation = ++_generation;
+
+        try
+        {
+            var page = await QueryAsync(cancellation.Token);
+            if (generation != _generation)
+                return false;
+
+            // A deletion or another PC can leave the requested page past the end.
+            if (page.Items.Count == 0 && page.Offset > 0 && page.Total > 0)
+            {
+                Offset = (page.Total - 1) / PageSize * PageSize;
+                page = await QueryAsync(cancellation.Token);
+                if (generation != _generation)
+                    return false;
+            }
+
+            Page = page;
+            return true;
+        }
+        catch (Exception) when (generation != _generation)
+        {
+            return false;
+        }
+        catch
+        {
+            Page = null;
+            throw;
+        }
+    }
+
+    private Task<NestPage> QueryAsync(CancellationToken cancellationToken) =>
+        _repository.QueryAsync(
+            new NestQuery
+            {
+                Search = Search,
+                Sort = Sort,
+                Descending = Descending,
+                Offset = Offset,
+                Limit = PageSize,
+            },
+            cancellationToken);
+
+    private static string Count(int value) => value.ToString("N0", CultureInfo.CurrentCulture);
+
+    /// <summary>Cancels any request in flight; the repository is not owned and stays open.</summary>
+    public void Dispose()
+    {
+        if (_disposed)
+            return;
+
+        _disposed = true;
+        _generation++;
+        _pending?.Cancel();
+        _pending?.Dispose();
+        _pending = null;
+    }
+}

OpenNest.Tests/Data/NestBrowseSessionTests.cs

@@ -0,0 +1,244 @@
+using OpenNest.Data;
+
+namespace OpenNest.Tests.Data;
+
+public class NestBrowseSessionTests
+{
+    [Fact]
+    public async Task Refresh_RequestsTheFirstBoundedPageNewestSavedFirst()
+    {
+        var repository = new PagedRepository(25);
+        using var session = new NestBrowseSession(repository, pageSize: 10);
+
+        Assert.True(await session.RefreshAsync());
+
+        var query = Assert.Single(repository.Queries);
+        Assert.Equal("", query.Search);
+        Assert.Equal(NestSortField.SavedAt, query.Sort);
+        Assert.True(query.Descending);
+        Assert.Equal(0, query.Offset);
+        Assert.Equal(10, query.Limit);
+        Assert.Equal(10, session.Page!.Items.Count);
+        Assert.Equal("Showing 1-10 of 25 nests", session.Summary);
+    }
+
+    [Fact]
+    public async Task NextAndPrevious_StayWithinTheMatches()
+    {
+        var repository = new PagedRepository(25);
+        using var session = new NestBrowseSession(repository, pageSize: 10);
+        await session.RefreshAsync();
+        Assert.False(session.CanGoPrevious);
+        Assert.True(session.CanGoNext);
+
+        Assert.True(await session.NextPageAsync());
+        Assert.Equal("Showing 11-20 of 25 nests", session.Summary);
+        Assert.True(await session.NextPageAsync());
+        Assert.Equal("Showing 21-25 of 25 nests", session.Summary);
+        Assert.False(session.CanGoNext);
+        Assert.True(session.CanGoPrevious);
+
+        var sent = repository.Queries.Count;
+        Assert.False(await session.NextPageAsync());
+        Assert.Equal(sent, repository.Queries.Count);
+
+        Assert.True(await session.PreviousPageAsync());
+        Assert.Equal(10, repository.Queries[^1].Offset);
+        Assert.Equal("Showing 11-20 of 25 nests", session.Summary);
+    }
+
+    [Fact]
+    public async Task SetSearch_TrimsTextAndReturnsToTheFirstPage()
+    {
+        var repository = new PagedRepository(25);
+        using var session = new NestBrowseSession(repository, pageSize: 10);
+        await session.RefreshAsync();
+        await session.NextPageAsync();
+
+        await session.SetSearchAsync("  beta works ");
+
+        var query = repository.Queries[^1];
+        Assert.Equal("beta works", query.Search);
+        Assert.Equal(0, query.Offset);
+        Assert.Equal("beta works", session.Search);
+    }
+
+    [Fact]
+    public async Task SortBy_NewColumnAscends_SameColumnReverses_AndResetsTheOffset()
+    {
+        var repository = new PagedRepository(25);
+        using var session = new NestBrowseSession(repository, pageSize: 10);
+        await session.RefreshAsync();
+        await session.NextPageAsync();
+
+        await session.SortByAsync(NestSortField.Customer);
+        Assert.Equal((NestSortField.Customer, false, 0), Last(repository));
+
+        await session.SortByAsync(NestSortField.Customer);
+        Assert.Equal((NestSortField.Customer, true, 0), Last(repository));
+
+        await session.SortByAsync(NestSortField.Thickness);
+        Assert.Equal((NestSortField.Thickness, false, 0), Last(repository));
+
+        await session.SortByAsync(NestSortField.SavedAt);
+        await session.SortByAsync(NestSortField.SavedAt);
+        Assert.Equal((NestSortField.SavedAt, true, 0), Last(repository));
+    }
+
+    [Fact]
+    public async Task OlderResponse_ArrivingLast_NeverReplacesTheNewerResult()
+    {
+        var repository = new ControlledRepository();
+        using var session = new NestBrowseSession(repository);
+        var older = session.SetSearchAsync("a");
+        var newer = session.SetSearchAsync("ab");
+        var newerPage = Page("ab result");
+
+        repository.Requests[1].Reply.SetResult(newerPage);
+        Assert.True(await newer);
+        repository.Requests[0].Reply.SetResult(Page("a result"));
+        Assert.False(await older);
+
+        Assert.Same(newerPage, session.Page);
+        Assert.True(repository.Requests[0].Token.IsCancellationRequested);
+        Assert.False(repository.Requests[1].Token.IsCancellationRequested);
+    }
+
+    [Fact]
+    public async Task SupersededFailure_IsIgnored_LatestFailure_ClearsThePageAndPropagates()
+    {
+        var repository = new ControlledRepository();
+        using var session = new NestBrowseSession(repository);
+        var older = session.SetSearchAsync("a");
+        var newer = session.SetSearchAsync("ab");
+
+        repository.Requests[0].Reply.SetException(new IOException("superseded failure"));
+        Assert.False(await older);
+        repository.Requests[1].Reply.SetResult(Page("ab result"));
+        Assert.True(await newer);
+        Assert.NotNull(session.Page);
+
+        var failing = session.RefreshAsync();
+        repository.Requests[2].Reply.SetException(new IOException("server offline"));
+        var error = await Assert.ThrowsAsync<IOException>(() => failing);
+
+        Assert.Equal("server offline", error.Message);
+        Assert.Null(session.Page);
+        Assert.Equal("", session.Summary);
+    }
+
+    [Fact]
+    public async Task Refresh_AfterTheLastPageWasEmptied_StepsBackToTheNewLastPage()
+    {
+        var repository = new PagedRepository(21);
+        using var session = new NestBrowseSession(repository, pageSize: 10);
+        await session.RefreshAsync();
+        await session.NextPageAsync();
+        await session.NextPageAsync();
+        Assert.Equal("Showing 21-21 of 21 nests", session.Summary);
+
+        repository.RemoveLast();
+        Assert.True(await session.RefreshAsync());
+
+        Assert.Equal(new[] { 20, 10 }, repository.Queries.TakeLast(2).Select(q => q.Offset));
+        Assert.Equal(10, session.Offset);
+        Assert.Equal("Showing 11-20 of 20 nests", session.Summary);
+    }
+
+    [Theory]
+    [InlineData("", "No nests on the server.")]
+    [InlineData("no such text", "No nests match the filter.")]
+    public async Task Summary_DistinguishesAnEmptyServerFromNoMatches(string search, string expected)
+    {
+        using var session = new NestBrowseSession(new PagedRepository(0));
+
+        await session.SetSearchAsync(search);
+
+        Assert.Equal(expected, session.Summary);
+    }
+
+    [Fact]
+    public async Task Dispose_CancelsTheRequestAndDiscardsItsLateResponse()
+    {
+        var repository = new ControlledRepository();
+        var session = new NestBrowseSession(repository);
+        var pending = session.SetSearchAsync("a");
+
+        session.Dispose();
+        repository.Requests[0].Reply.SetResult(Page("late"));
+
+        Assert.True(repository.Requests[0].Token.IsCancellationRequested);
+        Assert.False(await pending);
+        Assert.Null(session.Page);
+        await Assert.ThrowsAsync<ObjectDisposedException>(() => session.RefreshAsync());
+    }
+
+    [Theory]
+    [InlineData(0)]
+    [InlineData(NestQuery.MaxLimit + 1)]
+    public void Constructor_RejectsPageSizesTheServerWouldRefuse(int pageSize)
+    {
+        Assert.Throws<ArgumentOutOfRangeException>(() => new NestBrowseSession(new PagedRepository(0), pageSize));
+    }
+
+    private static (NestSortField, bool, int) Last(PagedRepository repository)
+    {
+        var query = repository.Queries[^1];
+        return (query.Sort, query.Descending, query.Offset);
+    }
+
+    private static NestPage Page(string name) =>
+        new() { Items = new[] { new NestRecord { Id = Guid.NewGuid(), Name = name } }, Total = 1, Limit = 100 };
+
+    /// <summary>Serves pages of an in-memory set and records each query.</summary>
+    private sealed class PagedRepository : RepositoryBase
+    {
+        private readonly List<NestRecord> _records;
+
+        public PagedRepository(int count) =>
+            _records = Enumerable.Range(0, count).Select(i => new NestRecord { Id = Guid.NewGuid(), Name = $"Nest {i}" }).ToList();
+
+        public List<NestQuery> Queries { get; } = new();
+
+        public void RemoveLast() => _records.RemoveAt(_records.Count - 1);
+
+        public override Task<NestPage> QueryAsync(NestQuery query, CancellationToken cancellationToken = default)
+        {
+            Queries.Add(query);
+            var matches = query.NormalizedSearch.Length == 0 ? _records : new List<NestRecord>();
+            return Task.FromResult(new NestPage
+            {
+                Items = matches.Skip(query.Offset).Take(query.Limit).ToArray(),
+                Total = matches.Count,
+                Offset = query.Offset,
+                Limit = query.Limit,
+            });
+        }
+    }
+
+    /// <summary>Leaves every query pending until the test completes it.</summary>
+    private sealed class ControlledRepository : RepositoryBase
+    {
+        public List<(NestQuery Query, TaskCompletionSource<NestPage> Reply, CancellationToken Token)> Requests { get; } = new();
+
+        public override Task<NestPage> QueryAsync(NestQuery query, CancellationToken cancellationToken = default)
+        {
+            var reply = new TaskCompletionSource<NestPage>();
+            Requests.Add((query, reply, cancellationToken));
+            return reply.Task;
+        }
+    }
+
+    private abstract class RepositoryBase : INestRepository
+    {
+        public abstract Task<NestPage> QueryAsync(NestQuery query, CancellationToken cancellationToken = default);
+
+        public Task<IReadOnlyList<NestRecord>> ListAsync(CancellationToken ct = default) => throw new NotSupportedException();
+        public Task<NestRecord?> GetMetadataAsync(Guid id, CancellationToken ct = default) => throw new NotSupportedException();
+        public Task<byte[]?> GetFileAsync(Guid id, CancellationToken ct = default) => throw new NotSupportedException();
+        public Task<NestRecord> UploadAsync(byte[] file, NestRecord record, CancellationToken ct = default) => throw new NotSupportedException();
+        public Task<NestRecord> UpdateFileAsync(Guid id, byte[] file, NestRecord record, CancellationToken ct = default) => throw new NotSupportedException();
+        public Task<NestRecord> UpdateMetadataAsync(Guid id, NestRecord record, CancellationToken ct = default) => throw new NotSupportedException();
+        public Task DeleteAsync(Guid id, CancellationToken ct = default) => throw new NotSupportedException();
+    }
+}

OpenNest/Forms/SavedNestsForm.cs

@@ -1,7 +1,5 @@
 using System;
-using System.Data;
 using System.Drawing;
-using System.Linq;
 using System.Threading.Tasks;
 using System.Windows.Forms;
 using OpenNest.Data;
@@ -9,18 +7,26 @@ using OpenNest.Data;
 namespace OpenNest.Forms;
 
 /// <summary>
-/// File &gt; Open (Database mode): lists nests from the shared nest server with
-/// filterable/sortable metadata columns, and lets the operator open or delete one.
+/// File &gt; Open (Database mode): browses nests on the shared nest server one bounded
+/// page at a time. Filtering, sorting and paging run on the server through
+/// <see cref="NestBrowseSession"/>; this form only renders its state.
 /// </summary>
 public sealed class SavedNestsForm : Form
 {
+    private const string IdColumn = "Id";
+    private const string LoadingText = "Loading...";
+
     private readonly INestRepository repository;
+    private readonly NestBrowseSession session;
     private readonly DataGridView grid;
     private readonly TextBox searchBox;
+    private readonly Timer searchTimer;
     private readonly Button openButton;
     private readonly Button deleteButton;
-    private readonly Button refreshButton;
-    private NestRecord[] records = Array.Empty<NestRecord>();
+    private readonly Button previousButton;
+    private readonly Button nextButton;
+    private readonly ToolStripStatusLabel statusLabel;
+    private int pendingRequests;
 
     /// <summary>Set to the chosen record's id when the dialog closes with OK.</summary>
     public Guid SelectedId { get; private set; }
@@ -28,6 +34,7 @@ public sealed class SavedNestsForm : Form
     public SavedNestsForm(INestRepository repository)
     {
         this.repository = repository;
+        session = new NestBrowseSession(repository);
 
         Text = "Open Nest — Database";
         StartPosition = FormStartPosition.CenterParent;
@@ -36,15 +43,37 @@ public sealed class SavedNestsForm : Form
         MaximizeBox = false;
         ShowInTaskbar = false;
 
-        var topPanel = new Panel { Dock = DockStyle.Top, Height = 34, Padding = new Padding(6) };
-        var searchLabel = new Label { Text = "Filter:", AutoSize = true, Location = new Point(6, 10) };
-        searchBox = new TextBox { Location = new Point(50, 6), Width = 300 };
-        searchBox.TextChanged += (_, _) => ApplyFilter();
-        refreshButton = new Button { Text = "Refresh", AutoSize = true, Location = new Point(360, 5) };
-        refreshButton.Click += async (_, _) => await LoadAsync();
+        var topPanel = new FlowLayoutPanel
+        {
+            Dock = DockStyle.Top,
+            Height = 34,
+            Padding = new Padding(3),
+            WrapContents = false,
+        };
+        var searchLabel = new Label { Text = "Filter:", AutoSize = true, Margin = new Padding(3, 7, 0, 0) };
+        searchBox = new TextBox { Width = 300, MaxLength = NestQuery.MaxSearchLength };
+        searchTimer = new Timer { Interval = 300 };
+        searchTimer.Tick += async (_, _) =>
+        {
+            searchTimer.Stop();
+            await RunAsync(() => session.SetSearchAsync(searchBox.Text));
+        };
+        searchBox.TextChanged += (_, _) =>
+        {
+            searchTimer.Stop();
+            searchTimer.Start();
+        };
+        var refreshButton = new Button { Text = "Refresh", AutoSize = true };
+        refreshButton.Click += async (_, _) => await RunAsync(session.RefreshAsync);
+        previousButton = new Button { Text = "< Previous", AutoSize = true, Enabled = false };
+        previousButton.Click += async (_, _) => await RunAsync(session.PreviousPageAsync);
+        nextButton = new Button { Text = "Next >", AutoSize = true, Enabled = false };
+        nextButton.Click += async (_, _) => await RunAsync(session.NextPageAsync);
         topPanel.Controls.Add(searchLabel);
         topPanel.Controls.Add(searchBox);
         topPanel.Controls.Add(refreshButton);
+        topPanel.Controls.Add(previousButton);
+        topPanel.Controls.Add(nextButton);
 
         grid = new DataGridView
         {
@@ -56,6 +85,32 @@ public sealed class SavedNestsForm : Form
             MultiSelect = false,
             AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.DisplayedCells,
         };
+        AddColumn("Name", NestSortField.Name, typeof(string));
+        AddColumn("Customer", NestSortField.Customer, typeof(string));
+        AddColumn("Status", NestSortField.Status, typeof(string));
+        AddColumn("Material", NestSortField.Material, typeof(string));
+        AddColumn("Date Created", NestSortField.DateCreated, typeof(DateTime));
+        AddColumn("Date Modified", NestSortField.DateModified, typeof(DateTime));
+        AddColumn("Thickness", NestSortField.Thickness, typeof(double));
+        AddColumn("Plates", NestSortField.PlateCount, typeof(int));
+        AddColumn("Parts", NestSortField.PartCount, typeof(int));
+        AddColumn("Made By", NestSortField.MadeBy, typeof(string));
+        AddColumn("Comments", NestSortField.Comments, typeof(string));
+        AddColumn("File Size", NestSortField.FileSize, typeof(long));
+        AddColumn("Saved", NestSortField.SavedAt, typeof(DateTime));
+        grid.Columns.Add(new DataGridViewTextBoxColumn
+        {
+            Name = IdColumn,
+            ValueType = typeof(Guid),
+            Visible = false,
+            SortMode = DataGridViewColumnSortMode.NotSortable,
+        });
+        // Sorting a page locally would misrepresent the archive; the server sorts all matches.
+        grid.ColumnHeaderMouseClick += async (_, e) =>
+        {
+            if (e.Button == MouseButtons.Left && grid.Columns[e.ColumnIndex].Tag is NestSortField field)
+                await RunAsync(() => session.SortByAsync(field));
+        };
         grid.CellDoubleClick += (_, e) =>
         {
             if (e.RowIndex >= 0)
@@ -78,6 +133,10 @@ public sealed class SavedNestsForm : Form
         buttons.Controls.Add(openButton);
         buttons.Controls.Add(deleteButton);
 
+        var statusStrip = new StatusStrip { SizingGrip = false };
+        statusLabel = new ToolStripStatusLabel { Spring = true, TextAlign = ContentAlignment.MiddleLeft };
+        statusStrip.Items.Add(statusLabel);
+
         grid.SelectionChanged += (_, _) =>
         {
             var hasSelection = grid.SelectedRows.Count > 0;
@@ -88,91 +147,72 @@ public sealed class SavedNestsForm : Form
         Controls.Add(grid);
         Controls.Add(topPanel);
         Controls.Add(buttons);
+        Controls.Add(statusStrip);
         CancelButton = cancel;
 
-        Shown += async (_, _) => await LoadAsync();
+        Shown += async (_, _) => await RunAsync(session.RefreshAsync);
     }
 
-    private async Task LoadAsync()
+    private void AddColumn(string name, NestSortField sortField, Type valueType)
     {
-        Cursor = Cursors.WaitCursor;
+        grid.Columns.Add(new DataGridViewTextBoxColumn
+        {
+            Name = name,
+            HeaderText = name,
+            ValueType = valueType,
+            SortMode = DataGridViewColumnSortMode.Programmatic,
+            Tag = sortField,
+        });
+    }
+
+    /// <summary>
+    /// Sends one browse request and renders its page. A request superseded by a newer one
+    /// renders nothing; a failure clears the rows and shows the error in the status line.
+    /// </summary>
+    private async Task RunAsync(Func<Task<bool>> request)
+    {
+        pendingRequests++;
+        UpdateNavigation();
+        statusLabel.Text = LoadingText;
         try
         {
-            var list = await repository.ListAsync();
-            if (IsDisposed)
-                return;
-            records = list.ToArray();
-            ApplyFilter();
+            if (await request() && !IsDisposed)
+                Populate(session.Page);
         }
         catch (Exception ex)
         {
             if (!IsDisposed)
-                MessageBox.Show(
-                    this,
-                    $"Could not load nests from the server: {ex.Message}",
-                    "Open Nest — Database",
-                    MessageBoxButtons.OK,
-                    MessageBoxIcon.Error
-                );
+            {
+                grid.Rows.Clear();
+                statusLabel.Text = $"Could not load nests from the server: {ex.Message}";
+            }
         }
         finally
         {
+            pendingRequests--;
             if (!IsDisposed)
-                Cursor = Cursors.Default;
+            {
+                UpdateNavigation();
+                // A request that was declined or superseded renders nothing of its own.
+                if (pendingRequests == 0 && statusLabel.Text == LoadingText)
+                    statusLabel.Text = session.Summary;
+            }
         }
     }
 
-    private void ApplyFilter()
+    private void UpdateNavigation()
     {
-        var filter = searchBox.Text.Trim();
-        var filtered = string.IsNullOrEmpty(filter)
-            ? records
-            : records
-                .Where(r =>
-                    Contains(r.Name, filter)
-                    || Contains(r.Customer, filter)
-                    || Contains(r.Material, filter)
-                    || Contains(r.MadeBy, filter)
-                    || Contains(r.Comments, filter)
-                    || Contains(r.Status.ToString(), filter)
-                    || Contains(FormatStatus(r.Status), filter)
-                    || Contains(r.DateCreated.ToString("g"), filter)
-                    || Contains(r.DateModified.ToString("g"), filter)
-                    || Contains(r.SavedAt.ToString("g"), filter)
-                    || Contains(r.Thickness.ToString(), filter)
-                    || Contains(r.PlateCount.ToString(), filter)
-                    || Contains(r.PartCount.ToString(), filter)
-                    || Contains(r.FileSize.ToString(), filter)
-                )
-                .ToArray();
-
-        Populate(filtered);
+        var idle = pendingRequests == 0;
+        previousButton.Enabled = idle && session.CanGoPrevious;
+        nextButton.Enabled = idle && session.CanGoNext;
     }
 
-    private static bool Contains(string value, string filter) =>
-        !string.IsNullOrEmpty(value) && value.Contains(filter, StringComparison.OrdinalIgnoreCase);
-
-    private void Populate(NestRecord[] rows)
+    private void Populate(NestPage page)
     {
-        var table = new DataTable();
-        table.Columns.Add("Name", typeof(string));
-        table.Columns.Add("Customer", typeof(string));
-        table.Columns.Add("Status", typeof(string));
-        table.Columns.Add("Material", typeof(string));
-        table.Columns.Add("Date Created", typeof(DateTime));
-        table.Columns.Add("Date Modified", typeof(DateTime));
-        table.Columns.Add("Thickness", typeof(double));
-        table.Columns.Add("Plates", typeof(int));
-        table.Columns.Add("Parts", typeof(int));
-        table.Columns.Add("Made By", typeof(string));
-        table.Columns.Add("Comments", typeof(string));
-        table.Columns.Add("File Size", typeof(long));
-        table.Columns.Add("Saved", typeof(DateTime));
-        table.Columns.Add("Id", typeof(Guid));
-
-        foreach (var record in rows.OrderByDescending(r => r.SavedAt))
+        grid.Rows.Clear();
+        foreach (var record in page.Items)
         {
-            table.Rows.Add(
+            grid.Rows.Add(
                 record.Name,
                 record.Customer,
                 FormatStatus(record.Status),
@@ -190,9 +230,14 @@ public sealed class SavedNestsForm : Form
             );
         }
 
-        grid.DataSource = table;
-        if (grid.Columns.Contains("Id"))
-            grid.Columns["Id"].Visible = false;
+        foreach (DataGridViewColumn column in grid.Columns)
+        {
+            column.HeaderCell.SortGlyphDirection = column.Tag is NestSortField field && field == session.Sort
+                ? session.Descending ? SortOrder.Descending : SortOrder.Ascending
+                : SortOrder.None;
+        }
+
+        statusLabel.Text = session.Summary;
     }
 
     private static string FormatStatus(NestStatus status) => status switch
@@ -207,7 +252,7 @@ public sealed class SavedNestsForm : Form
     {
         if (grid.SelectedRows.Count == 0)
             return;
-        SelectedId = (Guid)grid.SelectedRows[0].Cells["Id"].Value;
+        SelectedId = (Guid)grid.SelectedRows[0].Cells[IdColumn].Value;
         DialogResult = DialogResult.OK;
         Close();
     }
@@ -217,7 +262,7 @@ public sealed class SavedNestsForm : Form
         if (grid.SelectedRows.Count == 0)
             return;
 
-        var id = (Guid)grid.SelectedRows[0].Cells["Id"].Value;
+        var id = (Guid)grid.SelectedRows[0].Cells[IdColumn].Value;
         var name = grid.SelectedRows[0].Cells["Name"].Value?.ToString() ?? "";
 
         var confirm = MessageBox.Show(
@@ -235,7 +280,7 @@ public sealed class SavedNestsForm : Form
         {
             await repository.DeleteAsync(id);
             if (!IsDisposed)
-                await LoadAsync();
+                await RunAsync(session.RefreshAsync);
         }
         catch (Exception ex)
         {
@@ -254,4 +299,15 @@ public sealed class SavedNestsForm : Form
                 deleteButton.Enabled = grid.SelectedRows.Count > 0;
         }
     }
+
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing)
+        {
+            searchTimer.Dispose();
+            session.Dispose();
+        }
+
+        base.Dispose(disposing);
+    }
 }

docs/nest-storage.md

@@ -4,9 +4,13 @@ The desktop app can save nests two ways:
 
 - **File mode** (default, unchanged behavior): Save/Save As write a `.nest` ZIP
   archive to disk via the normal file dialog. See [nest-file-format.md](nest-file-format.md).
-- **Database mode**: Open lists server records with filterable metadata and
-  sortable columns; Save creates a record on first save and updates that same
-  record afterward. Save As creates a new record (a copy). A failed save keeps
+- **Database mode**: Open browses server records 100 at a time. The filter box
+  searches name, customer, material, made by, comments and status on the server
+  after a short typing pause; clicking a column header sorts every match on the
+  server (click again to reverse); Previous/Next move between pages and the
+  status line shows the range and total. Dates and numbers are not searched as
+  text; sort their column instead. Save creates a record on first save and
+  updates that same record afterward. Save As creates a new record (a copy). A failed save keeps
   the previous record association; switching server URLs creates a record on the
   new server rather than updating an id from the previous one. Delete in the
   saved-nest list permanently removes the selected server record after confirmation.