refactor<*>: rewrite all with AvaloniaUI

src/ViewModels/Discard.cs

@@ -0,0 +1,50 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+namespace SourceGit.ViewModels {
+    public class DiscardModeAll { }
+    public class DiscardModeSingle { public string File { get; set; } }
+    public class DiscardModeMulti { public int Count { get; set; } }
+
+    public class Discard : Popup {
+
+        public object Mode {
+            get;
+            private set;
+        }
+
+        public Discard(Repository repo, List<Models.Change> changes = null) {
+            _repo = repo;
+            _changes = changes;
+
+            if (_changes == null) {
+                Mode = new DiscardModeAll();
+            } else if (_changes.Count == 1) {
+                Mode = new DiscardModeSingle() { File = _changes[0].Path };
+            } else {
+                Mode = new DiscardModeMulti() { Count = _changes.Count };
+            }
+
+            View = new Views.Discard() { DataContext = this };
+        }
+
+        public override Task<bool> Sure() {
+            _repo.SetWatcherEnabled(false);
+            return Task.Run(() => {
+                if (_changes == null) {
+                    SetProgressDescription("Discard all local changes ...");
+                    Commands.Discard.All(_repo.FullPath);
+                } else {
+                    SetProgressDescription($"Discard total {_changes.Count} changes ...");
+                    Commands.Discard.Changes(_repo.FullPath, _changes);
+                }
+
+                CallUIThread(() => _repo.SetWatcherEnabled(true));
+                return true;
+            });
+        }
+
+        private Repository _repo = null;
+        private List<Models.Change> _changes = null;
+    }
+}