Data binding in Cocoa/Toffee

Elements Oxygene
1

I’m going to be starting my first real macOS app in elements. Could someone give me some pointers as to how Cocoa bindings work compared to .net binding? Any help would be appreciated!

2

Pretty simple:

  1. have read/write properties on your Controller (mark am optionally as [Notify] for clarity and/or to make sure they dont get name mangled or optimized away)
  2. in the Binding pane oin Interface Builder, select to bund to “File’s Owner” and specify the path, eg “self.myproperty”

See the new SharedUI sample thats in .2319 for an example.

3

I’m sorry Marc
the example works fine but not on Net… Oxygene at least

4

What part doesn’t work, and how does it fail?

5

I have changed in the constructor withController :

namespace SharedUI.Shared;
{$IF ECHOES}

uses
  System.Windows,
  System.Windows.Controls;

type
  MainWindow = public partial class(System.Windows.Window)
  public

    constructor withController(aController: MainWindowController);
    begin
      //DataContext := aController;
   // To this:
      controller := aController;
      InitializeComponent();
    end;
6

that’s wrong.

7

Ok but without the App crashes:

~> Process SharedUI.WPF started
~> An exception of type: System.NullReferenceException occurred and was ignored

Unbehandelte Ausnahme: System.NullReferenceException: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.
bei SharedUI.Shared.MainWindow.CalculateResult_Click(Object aSender, RoutedEventArgs e) in C:\Users\Public\Documents\RemObjects Samples\RemObjects Oxygene (Cross-Platform)\SharedUI\SharedUI.Shared\MainWindow.xaml.pas:Zeile 28.
bei System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
bei System.Windows.RouteItem.InvokeHandler(RoutedEventArgs routedEventArgs)
bei System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
bei System.Windows.EventRoute.InvokeHandlers(Object source, RoutedEventArgs args)
bei System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
bei System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
bei System.Windows.Controls.Primitives.ButtonBase.OnClick()
bei System.Windows.Controls.Button.OnClick()
bei System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
bei System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e)
bei System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
bei System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
bei System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
bei System.Windows.RouteItem.InvokeHandler(RoutedEventArgs routedEventArgs)
bei System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
bei System.Windows.EventRoute.ReInvokeHandlers(Object source, RoutedEventArgs args)
bei System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
bei System.Windows.UIElement.CrackMouseButtonEventAndReRaiseEvent(DependencyObject sender, MouseButtonEventArgs e)
bei System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e)
bei System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
bei System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
bei System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
bei System.Windows.RouteItem.InvokeHandler(RoutedEventArgs routedEventArgs)
bei System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
bei System.Windows.EventRoute.InvokeHandlers(Object source, RoutedEventArgs args)
bei System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
bei System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
bei System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
bei System.Windows.Input.InputManager.ProcessStagingArea()
bei System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
bei System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
bei System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
bei System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
bei System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
bei MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
bei MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
bei System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
bei System.Windows.Threading.Dispatcher.WrappedInvoke(Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
bei System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
bei System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
bei MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
bei MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
bei System.Windows.Threading.Dispatcher.TranslateAndDispatchMessage(MSG& msg)
bei System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
bei System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
bei System.Windows.Threading.Dispatcher.Run()
bei System.Windows.Application.RunDispatcher(Object ignore)
bei System.Windows.Application.RunInternal(Window window)
bei System.Windows.Application.Run(Window window)
bei System.Windows.Application.Run()
bei SharedUI.WPF.App.Main() in C:\Users\Public\Documents\RemObjects Samples\RemObjects Oxygene (Cross-Platform)\SharedUI\SharedUI.WPF\App.xaml:Zeile 2.
~> Process SharedUI.WPF terminated with exit code 0

8

Oh, oops, it looks like this got lost in converting the sample from C#. the property should be

    property controller: MainWindowController read DataContext as MainWindowController;
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