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using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.CompilerServices;
using System.Windows;
using Pfz.Caching;
using Pfz.DataTypes;
using Pfz.Threading.Contexts;
namespace Pfz.WpfControls
{
/// <summary>
/// Base class for PropertyBoundControls that are generic.
/// </summary>
public abstract class PropertyBoundControlBase:
BoundControl
{
internal void _Register(object dataContext)
{
if (dataContext == null)
return;
var hashset = PropertyBoundControl._boundControls.GetOrCreateValue(dataContext);
hashset.Add(this);
}
internal void _Unregister(object dataContext)
{
if (dataContext == null)
return;
WeakHashSet<PropertyBoundControlBase> hashset;
if (PropertyBoundControl._boundControls.TryGetValue(dataContext, out hashset))
hashset.Remove(this);
}
/// <summary>
/// Gets or sets the value of this controls.
/// </summary>
[SuppressMessage("Microsoft.Naming", "CA1721:PropertyNamesShouldNotMatchGetMethods")]
public abstract object Value { get; set; }
/// <summary>
/// Reads (refreshes) the value of the control from the data-source.
/// </summary>
public abstract void ReadFromDataSource();
/// <summary>
/// Sets the actual value of the control to the data-source.
/// </summary>
public abstract void ApplyToDataSource();
}
/// <summary>
/// A control bound to a property of an object.
/// </summary>
/// <typeparam name="ObjectType">The type of the DataSource property.</typeparam>
public class PropertyBoundControl<ObjectType>:
PropertyBoundControlBase
{
private ValueControl _valueControl = new ValueControl();
/// <summary>
/// Creates a new PropertyBoundControl instance.
/// </summary>
public PropertyBoundControl()
{
_valueControl.ValueChanged += _ValueControl_ValueChanged;
_valueControl.ValueChangeThrownException += _ValueControl_ValueChangeThrownException;
Content = _valueControl;
DataContextChanged += _DataContextChanged;
}
private void _DataContextChanged(object sender, DependencyPropertyChangedEventArgs e)
{
_Unregister(e.OldValue);
ReadFromDataSource();
_Register(e.NewValue);
}
void _ValueControl_ValueChangeThrownException(object sender, ValueExceptionEventArgs args)
{
args.RoutedEvent = ValueControl.ValueChangeThrownExceptionEvent;
RaiseEvent(args);
}
private void _ValueControl_ValueChanged(object sender, ValueChangedEventArgs args)
{
OnValueChanged(args);
ApplyToDataSource();
}
private PropertyBinding _propertyBinding;
/// <summary>
/// Gets or sets the PropertyBinding of this control.
/// </summary>
public PropertyBinding PropertyBinding
{
get
{
return _propertyBinding;
}
set
{
if (value == _propertyBinding)
return;
var dataContext = DataContext;
_Unregister(dataContext);
if (value != null)
value.Freeze();
_propertyBinding = value;
CreateContentNowIfNeeded();
_Register(dataContext);
}
}
/// <summary>
/// Applies the changes done to this control to its data-source.
/// </summary>
public override void ApplyToDataSource()
{
var binding = _propertyBinding;
if (binding == null)
return;
var property = binding.Property;
if (property == null)
return;
var dataSource = DataSource;
if (dataSource == null)
return;
if (_IsReadOnly())
return;
using(new ThreadErrors(dataSource))
{
try
{
object value = Value;
property.SetValue(dataSource, value, null);
}
catch(Exception exception)
{
ThreadErrors.AddError(property, exception.GetBaseException().Message);
}
if (ThreadErrors.HasErrors)
{
_CorrectErrors(ThreadErrors.GetGlobalErrors());
foreach(var hashset in ThreadErrors.GetErrorsDictionary().Values)
_CorrectErrors(hashset);
}
}
}
private void _CorrectErrors(HashSet<object> hashSet)
{
List<object> errorsToCorrect = new List<object>();
foreach(var error in hashSet)
if (!(error is PropertyError))
errorsToCorrect.Add(error);
var propertyInfo = _propertyBinding.Property;
foreach(var error in errorsToCorrect)
{
hashSet.Remove(error);
hashSet.Add(new PropertyError(propertyInfo, error));
}
}
private bool _canShowDisplayName = true;
/// <summary>
/// Gets or sets a value indicating is the DisplayName can be shown.
/// </summary>
[DefaultValue(true)]
public bool CanShowDisplayName
{
get
{
return _canShowDisplayName;
}
set
{
if (value == _canShowDisplayName)
return;
_canShowDisplayName = value;
if (value)
{
var binding = _propertyBinding;
if (binding == null)
_valueControl.DisplayName = null;
else
_valueControl.DisplayName = binding.ToString();
}
else
_valueControl.DisplayName = null;
}
}
/// <summary>
/// Gets or sets the object that is read/written as the data-source.
/// </summary>
public ObjectType DataSource
{
get
{
var result = DataContext;
if (!(result is ObjectType))
return default(ObjectType);
return (ObjectType)result;
}
set
{
DataContext = value;
}
}
/// <summary>
/// Gets or sets the value of this controls.
/// </summary>
public override object Value
{
get
{
return _valueControl.Value;
}
set
{
_valueControl.Value = value;
}
}
/// <summary>
/// Reads (refreshes) the value of the control from the data-source.
/// </summary>
public override void ReadFromDataSource()
{
var dataSource = DataSource;
if (dataSource == null)
{
_valueControl.Clear();
_valueControl.IsReadOnly = true;
return;
}
_valueControl.IsReadOnly = _IsReadOnly();
_valueControl.Value = _GetBoundValue();
}
private bool _IsReadOnly()
{
var binding = _propertyBinding;
if (binding == null)
return true;
var property = binding.Property;
if (property == null)
return true;
if (!property.CanWrite)
return true;
return IsReadOnly || BoundControl.IsDataSourceReadOnly(DataSource);
}
private object _GetBoundValue()
{
var dataSource = DataSource;
if (dataSource == null)
return null;
var binding = _propertyBinding;
if (binding == null)
return null;
var property = binding.Property;
if (property == null)
return null;
return property.GetValue(dataSource, null);
}
/// <summary>
/// Creates its content.
/// </summary>
protected override void OnCreateContent()
{
base.OnCreateContent();
var binding = _propertyBinding;
if (binding == null)
{
_valueControl.DataType = null;
_valueControl.DisplayName = null;
return;
}
if (_canShowDisplayName)
_valueControl.DisplayName = binding.ToString();
else
_valueControl.DisplayName = null;
var property = binding.Property;
if (property != null)
_valueControl.DataType = property.PropertyType;
ReadFromDataSource();
}
/// <summary>
/// Method invoked when the value of this control changes.
/// </summary>
protected virtual void OnValueChanged(ValueChangedEventArgs args)
{
args.RoutedEvent = ValueControl.ValueChangedEvent;
RaiseEvent(args);
}
/// <summary>
/// Event invoked when the value of this control changes.
/// </summary>
public event EventHandler<ValueChangedEventArgs> ValueChanged
{
add
{
AddHandler(ValueControl.ValueChangedEvent, value);
}
remove
{
RemoveHandler(ValueControl.ValueChangedEvent, value);
}
}
/// <summary>
/// Event invoked when an exception is thrown during the process of
/// ValueChange.
/// </summary>
public event EventHandler<ValueExceptionEventArgs> ValueChangeThrownException
{
add
{
AddHandler(ValueControl.ValueChangeThrownExceptionEvent, value);
}
remove
{
RemoveHandler(ValueControl.ValueChangeThrownExceptionEvent, value);
}
}
/// <summary>
/// Updates the internal Control IsReadOnlyProperty.
/// </summary>
protected override void OnIsReadOnlyChanged()
{
_valueControl.IsReadOnly = _IsReadOnly();
}
}
/// <summary>
/// A property-bound control that uses the DataSource as a System.Object.
/// </summary>
public sealed class PropertyBoundControl:
PropertyBoundControl<object>
{
internal static ConditionalWeakTable<object, WeakHashSet<PropertyBoundControlBase>> _boundControls = new ConditionalWeakTable<object, WeakHashSet<PropertyBoundControlBase>>();
/// <summary>
/// Gets all the PropertyBoundControls bound to an specific object.
/// </summary>
public static List<PropertyBoundControlBase> GetControlsBoundTo(object dataSource)
{
WeakHashSet<PropertyBoundControlBase> hashset;
if (_boundControls.TryGetValue(dataSource, out hashset))
return hashset.ToList();
return null;
}
/// <summary>
/// Applies all changes from PropertyBoundControls bound to the given dataSource.
/// </summary>
public static void ApplyToDataSource(object dataSource)
{
if (dataSource == null)
throw new ArgumentNullException("dataSource");
WeakHashSet<PropertyBoundControlBase> controls;
if (!_boundControls.TryGetValue(dataSource, out controls))
return;
using(new ThreadErrors(dataSource))
foreach(var control in controls)
control.ApplyToDataSource();
}
}
}
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I started to program computers when I was 11 years old, as a hobbyist, programming in AMOS Basic and Blitz Basic for Amiga.
At 12 I had my first try with assembler, but it was too difficult at the time. Then, in the same year, I learned C and, after learning C, I was finally able to learn assembler (for Motorola 680x0).
Not sure, but probably between 12 and 13, I started to learn C++. I always programmed "in an object oriented way", but using function pointers instead of virtual methods.
At 15 I started to learn Pascal at school and to use Delphi. At 16 I started my first internship (using Delphi). At 18 I started to work professionally using C++ and since then I've developed my programming skills as a professional developer in C++ and C#, generally creating libraries that help other developers do their work easier, faster and with less errors.
Want more info or simply want to contact me?
Take a look at:
http://paulozemek.azurewebsites.net/
Or e-mail me at: paulozemek@outlook.com
Codeproject MVP 2012, 2015 & 2016
Microsoft MVP 2013-2014 (in October 2014 I started working at Microsoft, so I can't be a Microsoft MVP anymore).