{

/// <summary>

/// Contain a reference to the collection of properties to show in the parent PropertyGrid.

/// </summary>

readonly List<PropertyDescriptor> m_PropertyDescriptors = new List<PropertyDescriptor>();

/// <summary>

/// Contain a reference to the array of properties to display in the PropertyGrid.

/// </summary>

AttributeCollection m_HiddenAttributes = null, m_BrowsableAttributes = null;

/// <summary>

/// Contain references to the arrays of properties or categories to hide.

/// </summary>

string[] m_BrowsableProperties = null, m_HiddenProperties = null;

/// <summary>

/// Contain a reference to the wrapper that contains the object to be displayed into the PropertyGrid.

/// </summary>

ObjectWrapper m_Wrapper = null;

/// <summary>

/// Public constructor.

/// </summary>

public FilteredGrid() => base.SelectedObject = m_Wrapper;

/// <summary>

///

/// </summary>

public new AttributeCollection BrowsableAttributes

{

get => m_BrowsableAttributes;

set

{

if (value == m_BrowsableAttributes) return;

m_HiddenAttributes = null;

m_BrowsableAttributes = value;

RefreshProperties();

}

}

/// <summary>

/// Get or set the categories to hide.

/// </summary>

public AttributeCollection HiddenAttributes

{

get => m_HiddenAttributes;

set

{

if (value == m_HiddenAttributes) return;

m_HiddenAttributes = value;

m_BrowsableAttributes = null;

RefreshProperties();

}

}

/// <summary>

/// Get or set the properties to show.

/// </summary>

public string[] BrowsableProperties

{

get => m_BrowsableProperties;

set

{

if (value == m_BrowsableProperties) return;

m_BrowsableProperties = value;

RefreshProperties();

}

}

/// <summary>

/// Get or set the properties to hide.

/// </summary>

public string[] HiddenProperties

{

get => m_HiddenProperties;

set

{

if (value == m_HiddenProperties) return;

m_HiddenProperties = value;

RefreshProperties();

}

}

/// <summary>

/// Overwrite the PropertyGrid.SelectedObject property.

/// </summary>

public new object SelectedObject

{

get => m_Wrapper != null ? ((ObjectWrapper)base.SelectedObject).SelectedObject : null;

set

{

if (value != null)

{

if (m_Wrapper is null)

{

m_Wrapper = new ObjectWrapper(value);

RefreshProperties();

}

else if (m_Wrapper.SelectedObject != value)

{

var needrefresh = value.GetType() != m_Wrapper.SelectedObject.GetType();

m_Wrapper.SelectedObject = value;

if (needrefresh) RefreshProperties();

}

// Set the list of properties to the wrapper.

m_Wrapper.PropertyDescriptors = m_PropertyDescriptors;

// Link the wrapper to the parent PropertyGrid.

base.SelectedObject = m_Wrapper;

}

else

{

m_Wrapper = null;

base.SelectedObject = null;

}

}

}

/// <summary>

/// Called when the browsable properties have changed.

/// </summary>

void OnBrowsablePropertiesChanged()

{

}

/// <summary>

/// Build the list of the properties to be displayed in the PropertyGrid, following the filters defined the Browsable and Hidden properties.

/// </summary>

void RefreshProperties()

{

if (m_Wrapper is null) return;

// Clear the list of properties to be displayed.

m_PropertyDescriptors.Clear();

// Check whether the list is filtered

if (!m_BrowsableAttributes.IsNullOrEmpty())

{

// Add to the list the attributes that need to be displayed.

foreach(Attribute attribute in m_BrowsableAttributes) ShowAttribute(attribute);

}

else

{

// Fill the collection with all the properties.

var originalpropertydescriptors = TypeDescriptor.GetProperties(m_Wrapper.SelectedObject);

foreach(PropertyDescriptor propertydescriptor in originalpropertydescriptors) m_PropertyDescriptors.Add(propertydescriptor);

// Remove from the list the attributes that mustn't be displayed.

if(m_HiddenAttributes != null) foreach(Attribute attribute in m_HiddenAttributes) HideAttribute(attribute);

}

// Get all the properties of the SelectedObject

var allproperties = TypeDescriptor.GetProperties(m_Wrapper.SelectedObject);

// Hide if necessary, some properties

if (!m_HiddenProperties.IsNullOrEmpty())

{

// Remove from the list the properties that mustn't be displayed.

foreach(var propertyname in m_HiddenProperties)

{

try

{

// Remove from the list the property

HideProperty(allproperties[propertyname]);

}

catch(Exception ex)

{

throw new ArgumentException(ex.Message);

}

}

}

if (!m_BrowsableProperties.IsNullOrEmpty())

{

// Clear properties to filter the list from scratch BY IAP

m_PropertyDescriptors.Clear();

foreach(string propertyname in m_BrowsableProperties)

{

try

{

ShowProperty(allproperties[propertyname]);

}

catch (Exception)

{

throw new ArgumentException("Property not found.", propertyname);

}

}

}

m_PropertyDescriptors.Sort(CompareDescriptors);

}

/// <summary>

/// Compare two property descriptors.

/// </summary>

static int CompareDescriptors(PropertyDescriptor a, PropertyDescriptor b)

{

if (a is null) return b is null ? 0 : -1;

if (b is null) return 1;

int value = string.Compare(a.Category, b.Category);

return value == 0 ? string.Compare(a.DisplayName, b.DisplayName) : value;

}

/// <summary>

/// Allows to hide a set of properties to the parent PropertyGrid.

/// </summary>

void HideAttribute(Attribute attribute)

{

var collection = TypeDescriptor.GetProperties(m_Wrapper.SelectedObject, new[] { attribute });

if(collection.IsNullOrEmpty()) throw new ArgumentException("Attribute not found", attribute.ToString());

foreach(PropertyDescriptor propertydescriptor in collection) HideProperty(propertydescriptor);

}

/// <summary>

/// Add all the properties that match an attribute to the list of properties to be displayed in the PropertyGrid.

/// </summary>

void ShowAttribute(Attribute attribute)

{

var collection = TypeDescriptor.GetProperties(m_Wrapper.SelectedObject,new[] { attribute });

if (collection.IsNullOrEmpty()) throw new ArgumentException("Attribute not found", attribute.ToString());

foreach(PropertyDescriptor propertydescriptor in collection) ShowProperty(propertydescriptor);

}

/// <summary>

/// Add a property to the list of properties to be displayed in the PropertyGrid.

/// </summary>

void ShowProperty(PropertyDescriptor property)

{

if (!m_PropertyDescriptors.Contains(property)) m_PropertyDescriptors.Add(property);

}

/// <summary>

/// Allows to hide a property to the parent PropertyGrid.

/// </summary>

void HideProperty(PropertyDescriptor property)

{

if (m_PropertyDescriptors.Contains(property)) m_PropertyDescriptors.Remove(property);

}

{

/// <summary>

/// Simple constructor.

/// </summary>

/// <param name="obj">A reference to the selected object that will linked to the parent PropertyGrid.</param>

internal ObjectWrapper(object obj) => SelectedObject = obj;

/// <summary>

/// Get or set a reference to the selected object that will linked to the parent PropertyGrid.

/// </summary>

public object SelectedObject { get; set; }

/// <summary>

/// Get or set a reference to the collection of properties to show in the parent PropertyGrid.

/// </summary>

public List<PropertyDescriptor> PropertyDescriptors { get; set; } = new List<PropertyDescriptor>();

#region ICustomTypeDescriptor Members

public PropertyDescriptorCollection GetProperties(Attribute[] attributes) => GetProperties();

public PropertyDescriptorCollection GetProperties() => new PropertyDescriptorCollection(PropertyDescriptors.ToArray(), true);

public AttributeCollection GetAttributes() => TypeDescriptor.GetAttributes(SelectedObject, true);

public string GetClassName() => TypeDescriptor.GetClassName(SelectedObject, true);

public string GetComponentName() => TypeDescriptor.GetComponentName(SelectedObject, true);

public TypeConverter GetConverter() => TypeDescriptor.GetConverter(SelectedObject, true);

public EventDescriptor GetDefaultEvent() => TypeDescriptor.GetDefaultEvent(SelectedObject, true);

public PropertyDescriptor GetDefaultProperty() => TypeDescriptor.GetDefaultProperty(SelectedObject, true);

public object GetEditor(Type editorBaseType) => TypeDescriptor.GetEditor(this, editorBaseType, true);

public EventDescriptorCollection GetEvents(Attribute[] attributes) => TypeDescriptor.GetEvents(SelectedObject, attributes, true);

public EventDescriptorCollection GetEvents() => TypeDescriptor.GetEvents(SelectedObject, true);

public object GetPropertyOwner(PropertyDescriptor pd) => SelectedObject;

#endregion