New features/APIs
#5996 Port tab navigation algorithm from WPF (including TabIndex support)
#6029 #6183 Transitions for solid color brushes + Gradient animations
#6174 #6310 [OSX] [Windows] Cancellable IClassicDesktopStyleApplicationLifetime.ShutdownRequested event
#6347 Add CornerRadius to TemplatedControl and use it where possible
#6076 Add API to get FrameSize of a window
#6023 TextBox: Add IsUndoEnabled and UndoLimit
#6058 Add PolyLineSegment path segment
#6059 Add ContextRequest event, use it to show ContextFlyout/ContextMenu, allow to open context using keyboard
#6082 Allow setting custom Animator in property to Setter (attached property alternative)
#6133 Add Arc shape control
#6175 Add "Star" static to GridLength
#6210 Add ItemsControl.IsTextSearchEnabled
#6220 Expose EnsureCapacity() on AvaloniaList
#6235 Allow for disabling clipping of adorners. Cleanup AdornerLayer class
#6313 Add ClipGeometry and OpacityMask properties to DrawingGroup
#6322 Properties of PointerEventArgs in TappedEventArgs
#6379 Allow for controlling delay of scrollbar hide/show.
#6430 Add Not value converter to BoolConverters
#6101 [Linux] Adds a pixel format parameter to Linux frame buffer platform setup.
Dev-Tools
#6191 Support for inspecting Popup visual tree
#6074 Configurable startup screen
#6046 #6049 Fix log errors
#6176 Adding more ToString() overloads to improve DevTools
#5998 Enable nullable on Avalonia.Diagnostics project
Bugfixes
#6052 [Linux] Fix dialogs crashing on X11 when Title is set to null
#6188 [Osx] Fix child window activation
#6199 [Osx] Fix com issues
#6212 [Osx] Fix initial keyboard input
#6245 [Osx] Window state - keep field in sync.
#6250 [Osx] Fix window flicker
#6258 [Osx] Fix light dismiss overlay intercepting titlebar hit tests for OSX.
#6407 [Osx] Fix a couple of minimized WindowState bugs
#6425 [Osx] Fix tab shortcuts in NativeMenu
#6266 [Osx] Fix showing window with no specified size.
#6268 [Osx] Fix existing and add missing osx-specific key shortcuts
#6083 [Osx] Fix window state logic.
#6340 Fix DataGrid wheel scroll calculation
#5055 Fix crash when KeyBindings change while they are being handled
#5858 Fix ArgumentNullException in TreeView.ExpandSubTree()
#6016 Fix light dismiss overlay intercepting titlebar hit tests.
#6039 Fix problems with mutable brush being passed to an immutable pen.
#6064 Fix fetching neutral value in animations.
#6066 Fix gradient brush target rectangles.
#6069 Fix RemoteWidget error when width or height is equal to zero. Issue.
#6072 Ensure we unsubscribe from PropertyChanged in AnimationInstance
#6091 Scale flyout transient area.
#6092 Implement measure pass in AdornerLayer.
#6093 ScrollContentPresenter, fix order of operations, set Offset before setting Extent
#6135 Use IsNullOrEmpty instead of IsNullOrWhiteSpace for :empty pseudoclass
#6146 Prevent ScrollSlotIntoView from crashing on start
#6151 Fixes issue with Alt+F4 on ComboBox
#6213 Fixes/textbox crash when focused but not visible
#6242 Invalidating measure on TransformedBounds update
#6244 Fix: Thumb should handle pointer capture loss
#6246 Fix "." (empty) paths with compiled bindings.
#6251 Fix DataGrid column sorting with inherited interface property
#6254 Fix autosizing when DPI changed
#6271 Implement indexed sort for visual children.
#6283 fixes(DataGrid): Fixes DataGridColumn IsVisible binding
#6373 Fix skia OpacityMask push and pop methods
#6380 [OverlayPopupHost] remove render white rect override
#6429 Check if TextBox.Text is null in AutoCompleteBox
Misc
#6341 [Windows] Win32 WindowImpl: Don't change z-order when Position is set
#6351 Add comments about OSX,Linux, Windows platform options
#6187 Allow moving items in ItemsRepeater
#6374 Enable antialiasing for PushGeometryClip
#6024 Remove timer on UndoRedoHelper and manually manage undo/redo snapshots a bit more
#6032 Use immutable data to limit allocations.
#6022 SelectedDate and SelectedTime => TwoWay by default
#6053 Fix caret positioning with empty newlines
#6105 ComboBox: Let Data and Stretch be overridden
#6198 Validate parent/owner when showing windows
#6228 Makes TextBox.UndoRedoState struct readonly
#6275 [DataGrid] Invert ascending/descending arrows for Fluent Theme and match their behaviour with Simple Theme
#6285 Remove TextBox margin hack
#6342 Improve DataGrid scrolling (horizontal wheel + touch)
#6361 Enable multitouch on X11,Windows by default
#6362 Respect CancellationToken in InternalPlatformThreadingInterface.RunLoop.