optimize<*>: reduce memory usage

src/ViewModels/CommitDetail.cs

@@ -114,6 +114,24 @@ namespace SourceGit.ViewModels {
             _repo = repo;
         }
 
+        public void Cleanup() {
+            _repo = null;
+            _commit = null;
+            if (_changes != null) _changes.Clear();
+            if (_visibleChanges != null) _visibleChanges.Clear();
+            if (_changeTree != null) _changeTree.Clear();
+            _selectedChange = null;
+            _selectedChangeNode = null;
+            _searchChangeFilter = null;
+            _diffContext = null;
+            if (_revisionFiles != null) _revisionFiles.Clear();
+            if (_revisionFilesTree != null) _revisionFilesTree.Clear();
+            _selectedRevisionFileNode = null;
+            _searchFileFilter = null;
+            _viewRevisionFileContent = null;
+            _cancelToken = null;
+        }
+
         public void NavigateTo(string commitSHA) {
             var repo = Preference.FindRepository(_repo);
             if (repo != null) repo.NavigateToCommit(commitSHA);

src/ViewModels/Histories.cs

@@ -56,6 +56,22 @@ namespace SourceGit.ViewModels {
             _repo = repo;
         }
 
+        public void Cleanup() {
+            Commits = new List<Models.Commit>();
+
+            _repo = null;
+            _graph = null;
+            _autoSelectedCommit = null;
+
+            if (_detailContext is CommitDetail cd) {
+                cd.Cleanup();
+            } else if (_detailContext is RevisionCompare rc) {
+                rc.Cleanup();
+            }
+
+            _detailContext = null;
+        }
+
         public void NavigateTo(string commitSHA) {
             var commit = _commits.Find(x => x.SHA.StartsWith(commitSHA));
             if (commit != null) {

src/ViewModels/Launcher.cs

@@ -1,5 +1,8 @@
 using Avalonia.Collections;
+using Avalonia.Markup.Xaml.MarkupExtensions;
 using CommunityToolkit.Mvvm.ComponentModel;
+using System;
+using System.Collections.Generic;
 using System.IO;
 
 namespace SourceGit.ViewModels {
@@ -74,8 +77,6 @@ namespace SourceGit.ViewModels {
             LauncherPage page = param as LauncherPage;
             if (page == null) page = _activePage;
 
-            CloseRepositoryInTab(page);
-
             var removeIdx = Pages.IndexOf(page);
             var activeIdx = Pages.IndexOf(_activePage);
             if (removeIdx == activeIdx) {
@@ -85,31 +86,37 @@ namespace SourceGit.ViewModels {
                     ActivePage = Pages[removeIdx + 1];
                 }
 
+                CloseRepositoryInTab(page);
                 Pages.RemoveAt(removeIdx);
                 OnPropertyChanged(nameof(Pages));
             } else if (removeIdx + 1 == activeIdx) {
+                CloseRepositoryInTab(page);
                 Pages.RemoveAt(removeIdx);
                 OnPropertyChanged(nameof(Pages));
             } else {
+                CloseRepositoryInTab(page);
                 Pages.RemoveAt(removeIdx);
             }
+
+            GC.Collect();
         }
 
         public void CloseOtherTabs(object param) {
             if (Pages.Count == 1) return;
 
-            LauncherPage page = param as LauncherPage;
+            var page = param as LauncherPage;
             if (page == null) page = _activePage;
 
+            ActivePage = page;
+
             foreach (var one in Pages) {
-                if (one.Node.Id != page.Node.Id) {
-                    CloseRepositoryInTab(one);
-                }
+                if (one.Node.Id != page.Node.Id) CloseRepositoryInTab(one);
             }
 
-            ActivePage = page;
             Pages = new AvaloniaList<LauncherPage> { page };
             OnPropertyChanged(nameof(Pages));
+
+            GC.Collect();
         }
 
         public void CloseRightTabs(object param) {
@@ -126,6 +133,8 @@ namespace SourceGit.ViewModels {
                 CloseRepositoryInTab(Pages[i]);
                 Pages.Remove(Pages[i]);
             }
+
+            GC.Collect();
         }
 
         public void OpenRepositoryInTab(RepositoryNode node, LauncherPage page) {
@@ -164,13 +173,15 @@ namespace SourceGit.ViewModels {
         }
 
         private void CloseRepositoryInTab(LauncherPage page) {
-            if (!page.Node.IsRepository) return;
+            if (page.Node.IsRepository) {
+                var repo = Preference.FindRepository(page.Node.Id);
+                if (repo != null) {
+                    Commands.AutoFetch.RemoveRepository(repo.FullPath);
+                    repo.Close();
+                }
+            }
 
-            var repo = Preference.FindRepository(page.Node.Id);
-            if (repo == null) return;
-
-            Commands.AutoFetch.RemoveRepository(repo.FullPath);
-            repo.Close();
+            page.View = null;
         }
 
         private LauncherPage _activePage = null;

src/ViewModels/Repository.cs

@@ -189,12 +189,17 @@ namespace SourceGit.ViewModels {
         }
 
         public void Close() {
+            SelectedView = 0.0; // Do NOT modify. Used to remove exists widgets for GC.Collect
+
             _watcher.Dispose();
+            _histories.Cleanup();
+            _workingCopy.Cleanup();
+            _stashesPage.Cleanup();
+
             _watcher = null;
             _histories = null;
             _workingCopy = null;
             _stashesPage = null;
-            _selectedView = null;
             _isSearching = false;
             _searchCommitFilter = string.Empty;
 
@@ -205,8 +210,6 @@ namespace SourceGit.ViewModels {
             _tags.Clear();
             _submodules.Clear();
             _searchedCommits.Clear();
-
-            GC.Collect();
         }
 
         public void OpenInFileManager() {

src/ViewModels/RevisionCompare.cs

@@ -96,6 +96,17 @@ namespace SourceGit.ViewModels {
             });
         }
 
+        public void Cleanup() {
+            _repo = null;
+            if (_changes != null) _changes.Clear();
+            if (_visibleChanges != null) _visibleChanges.Clear();
+            if (_changeTree != null) _changeTree.Clear();
+            _selectedChange = null;
+            _selectedNode = null;
+            _searchFilter = null;
+            _diffContext = null;
+        }
+
         public void NavigateTo(string commitSHA) {
             var repo = Preference.FindRepository(_repo);
             if (repo != null) repo.NavigateToCommit(commitSHA);

src/ViewModels/StashesPage.cs

@@ -67,6 +67,15 @@ namespace SourceGit.ViewModels {
             _repo = repo;
         }
 
+        public void Cleanup() {
+            _repo = null;
+            if (_stashes != null) _stashes.Clear();
+            _selectedStash = null;
+            if (_changes != null) _changes.Clear();
+            _selectedChange = null;
+            _diffContext = null;
+        }
+
         public void Apply(object param) {
             if (param is Models.Stash stash) {
                 Task.Run(() => {

src/ViewModels/WorkingCopy.cs

@@ -78,6 +78,17 @@ namespace SourceGit.ViewModels {
             _repo = repo;
         }
 
+        public void Cleanup() {
+            _repo = null;
+            if (_unstaged != null) _unstaged.Clear();
+            if (_staged != null) _staged.Clear();
+            if (_unstagedTree != null) _unstagedTree.Clear();
+            if (_stagedTree != null) _stagedTree.Clear();
+            _lastViewChange = null;
+            _detailContext = null;
+            _commitMessage = string.Empty;
+        }
+
         public bool SetData(List<Models.Change> changes) {
             var unstaged = new List<Models.Change>();
             var staged = new List<Models.Change>();

src/Views/Repository.axaml

@@ -466,6 +466,10 @@
             <DataTemplate DataType="vm:StashesPage">
               <v:StashesPage/>
             </DataTemplate>
+
+            <DataTemplate DataType="x:Double">
+              <Border/>
+            </DataTemplate>
           </ContentControl.DataTemplates>
         </ContentControl>
       </Grid>