internal object GetEditor(object instance, Type editorBaseType)
{
EditorAttribute typeAttr;
// For instances, the design time object for them may want to redefine the
// attributes. So, we search the attribute here based on the instance. If found,
// we then search on the same attribute based on type. If the two don't match, then
// we cannot cache the value and must re-create every time. It is rare for a designer
// to override these attributes, so we want to be smart here.
//
if (instance != null)
{
typeAttr = GetEditorAttribute(TypeDescriptor.GetAttributes(_type), editorBaseType);
EditorAttribute instanceAttr = GetEditorAttribute(TypeDescriptor.GetAttributes(instance), editorBaseType);
if (typeAttr != instanceAttr)
{
Type editorType = GetTypeFromName(instanceAttr.EditorTypeName);
if (editorType != null && editorBaseType.GetTypeInfo().IsAssignableFrom(editorType))
{
return ReflectTypeDescriptionProvider.CreateInstance(editorType, _type);
}
}
}
// If we got here, we return our type-based editor.
//
lock (this)
{
for (int idx = 0; idx < _editorCount; idx++)
{
if (_editorTypes[idx] == editorBaseType)
{
return _editors[idx];
}
}
}
// Editor is not cached yet. Look in the attributes.
//
object editor = null;
typeAttr = GetEditorAttribute(TypeDescriptor.GetAttributes(_type), editorBaseType);
if (typeAttr != null)
{
Type editorType = GetTypeFromName(typeAttr.EditorTypeName);
if (editorType != null && editorBaseType.GetTypeInfo().IsAssignableFrom(editorType))
{
editor = ReflectTypeDescriptionProvider.CreateInstance(editorType, _type);
}
}
// Editor is not in the attributes. Search intrinsic tables.
//
if (editor == null)
{
Hashtable intrinsicEditors = ReflectTypeDescriptionProvider.GetEditorTable(editorBaseType);
if (intrinsicEditors != null)
{
editor = ReflectTypeDescriptionProvider.SearchIntrinsicTable(intrinsicEditors, _type);
}
// As a quick sanity check, check to see that the editor we got back is of
// the correct type.
//
if (editor != null && !editorBaseType.GetTypeInfo().IsInstanceOfType(editor))
{
Debug.Fail("Editor " + editor.GetType().FullName + " is not an instance of " + editorBaseType.FullName + " but it is in that base types table.");
editor = null;
}
}
if (editor != null)
{
lock (this)
{
if (_editorTypes == null || _editorTypes.Length == _editorCount)
{
int newLength = (_editorTypes == null ? 4 : _editorTypes.Length * 2);
Type[] newTypes = new Type[newLength];
object[] newEditors = new object[newLength];
if (_editorTypes != null)
{
_editorTypes.CopyTo(newTypes, 0);
_editors.CopyTo(newEditors, 0);
}
_editorTypes = newTypes;
_editors = newEditors;
_editorTypes[_editorCount] = editorBaseType;
_editors[_editorCount++] = editor;
}
}
}
return editor;
}
