/// <summary>
/// Gets a list of <see cref="IGalleryItem"/>s from the given <see cref="IDragDropObject">data wrapper</see>.
/// </summary>
/// <param name="dataObject">The data wrapper object.</param>
/// <returns>A <see cref="IList{T}"/> of <see cref="IGalleryItem"/>s, or null if the wrapper did not contain a list of 0 or more IGalleryItems.</returns>
protected IList<IGalleryItem> ExtractGalleryItemList(IDragDropObject dataObject)
{
IList<IGalleryItem> itemlist = null;
if (dataObject.HasData<IList<IGalleryItem>>())
{
itemlist = dataObject.GetData<IList<IGalleryItem>>();
}
foreach (string format in dataObject.GetFormats())
{
object obj = dataObject.GetData(format);
if (obj is IList<IGalleryItem>)
itemlist = obj as IList<IGalleryItem>;
}
if (itemlist != null && itemlist.Count == 0)
return null;
return itemlist;
}
/// <summary>
///
/// </summary>
/// <param name="droppedData"></param>
/// <param name="targetItem"></param>
/// <param name="action"></param>
/// <param name="modifiers"></param>
/// <returns></returns>
public override sealed DragDropOption PerformDrop(IDragDropObject droppedData, IGalleryItem targetItem, DragDropOption action, ModifierFlags modifiers)
{
DragDropOption performedAction;
IList <IGalleryItem> droppedItems = ExtractGalleryItemList(droppedData);
if (droppedItems != null)
{
if (_draggedItems == droppedItems)
{
performedAction = PerformDropLocalItems(droppedItems, targetItem, action, modifiers);
}
else
{
performedAction = PerformDropForeignItems(droppedItems, targetItem, action, modifiers);
}
}
else
{
performedAction = PerformDropForeignObject(droppedData, targetItem, action, modifiers);
}
return(performedAction);
}
/// <summary>
/// Checks for allowed drag & drop actions involving the specified foreign data and the given target on this component.
/// </summary>
/// <param name="droppingData">The <see cref="IDragDropObject"/> object that encapsulates all forms of the foreign data.</param>
/// <param name="targetItem">The target item that the user is trying to drop on to.</param>
/// <param name="actions"></param>
/// <param name="modifiers">The modifier keys that are being held by the user.</param>
/// <returns>The allowed <see cref="DragDropKind"/> action for this attempted drag & drop operation.</returns>
public override sealed DragDropOption CheckDrop(IDragDropObject droppingData, IGalleryItem targetItem, DragDropOption actions, ModifierFlags modifiers)
{
DragDropOption allowedActions;
IList <IGalleryItem> droppingItems = ExtractGalleryItemList(droppingData);
if (droppingItems != null)
{
if (_draggedItems == droppingItems)
{
allowedActions = CheckDropLocalItems(droppingItems, targetItem, actions, modifiers);
}
else
{
allowedActions = CheckDropForeignItems(droppingItems, targetItem, actions, modifiers);
}
}
else
{
allowedActions = CheckDropForeignObject(droppingData, targetItem, actions, modifiers);
}
return(actions & allowedActions);
}
/// <summary>
/// Gets a list of <see cref="IGalleryItem"/>s from the given <see cref="IDragDropObject">data wrapper</see>.
/// </summary>
/// <param name="dataObject">The data wrapper object.</param>
/// <returns>A <see cref="IList{T}"/> of <see cref="IGalleryItem"/>s, or null if the wrapper did not contain a list of 0 or more IGalleryItems.</returns>
protected IList <IGalleryItem> ExtractGalleryItemList(IDragDropObject dataObject)
{
IList <IGalleryItem> itemlist = null;
if (dataObject.HasData <IList <IGalleryItem> >())
{
itemlist = dataObject.GetData <IList <IGalleryItem> >();
}
foreach (string format in dataObject.GetFormats())
{
object obj = dataObject.GetData(format);
if (obj is IList <IGalleryItem> )
{
itemlist = obj as IList <IGalleryItem>;
}
}
if (itemlist != null && itemlist.Count == 0)
{
return(null);
}
return(itemlist);
}
/// <summary>
///
/// </summary>
/// <param name="droppedData"></param>
/// <param name="targetItem"></param>
/// <param name="action"></param>
/// <param name="modifiers"></param>
/// <returns></returns>
public virtual DragDropOption PerformDrop(IDragDropObject droppedData, IGalleryItem targetItem, DragDropOption action, ModifierFlags modifiers)
{
return(DragDropOption.None);
}
/// <summary>
///
/// </summary>
/// <remarks>
/// This method or <see cref="PerformDrop(IDragDropObject,IGalleryItem,DragDropOption,ModifierFlags)"/> may be called
/// additional times if the returned action is <see cref="DragDropOption.None"/> in order to attempt other ways to drop the item in
/// an acceptable manner. It is thus very important that the result be set properly if the drop was accepted and no further attempts
/// should be made.
/// </remarks>
/// <param name="droppedData"></param>
/// <param name="targetIndex"></param>
/// <param name="action"></param>
/// <param name="modifiers"></param>
/// <returns></returns>
public virtual DragDropOption PerformDrop(IDragDropObject droppedData, int targetIndex, DragDropOption action, ModifierFlags modifiers)
{
return(DragDropOption.None);
}
/// <summary>
/// Checks for allowed drag & drop actions involving the specified foreign data and the given target on this component.
/// </summary>
/// <param name="droppingData">The <see cref="IDragDropObject"/> object that encapsulates all forms of the foreign data.</param>
/// <param name="targetItem">The target item that the user is trying to drop on to.</param>
/// <param name="actions"></param>
/// <param name="modifiers">The modifier keys that are being held by the user.</param>
/// <returns>The allowed <see cref="DragDropKind"/> action for this attempted drag & drop operation.</returns>
public virtual DragDropOption CheckDrop(IDragDropObject droppingData, IGalleryItem targetItem, DragDropOption actions, ModifierFlags modifiers)
{
return(DragDropOption.None);
}
/// <summary>
/// Checks for allowed drag & drop actions involving the specified foreign data and the given target on this component.
/// </summary>
/// <param name="droppingData">The <see cref="IDragDropObject"/> object that encapsulates all forms of the foreign data.</param>
/// <param name="targetIndex">The target index that the user is trying to drop at.</param>
/// <param name="actions"></param>
/// <param name="modifiers">The modifier keys that are being held by the user.</param>
/// <returns>The allowed <see cref="DragDropKind"/> actions for this attempted drag & drop operation.</returns>
public virtual DragDropOption CheckDrop(IDragDropObject droppingData, int targetIndex, DragDropOption actions, ModifierFlags modifiers)
{
return(DragDropOption.None);
}
/// <summary>
/// Performs a drag-drop of a non-<see cref="IGalleryItem"/> object from outside this gallery on top of the specified item.
/// </summary>
/// <param name="droppedData">The data object to drop.</param>
/// <param name="targetItem">The target <see cref="IGalleryItem"/> at which the <paramref name="droppedData"/> is being dropped.</param>
/// <param name="actions">The interaction to take.</param>
/// <param name="modifiers">The modifier keys that were pressed at the time of the drop.</param>
/// <returns>The actual interaction on the <paramref name="droppedData"/> that was taken.</returns>
protected virtual DragDropOption PerformDropForeignObject(IDragDropObject droppedData, IGalleryItem targetItem, DragDropOption actions, ModifierFlags modifiers)
{
return(DragDropOption.None);
}
/// <summary>
/// Checks if drag-dropping non-<see cref="IGalleryItem"/> objects from outside this gallery to the specified index is allowed.
/// </summary>
/// <param name="droppingData">The data object to drop.</param>
/// <param name="targetIndex">The target index at which the <paramref name="droppingData"/> is being dropped.</param>
/// <param name="actions">The interactions that are being allowed by the data source.</param>
/// <param name="modifiers">The modifier keys that currently being pressed.</param>
/// <returns>The allowed interactions for dropping the <paramref name="droppingData"/> here.</returns>
protected virtual DragDropOption CheckDropForeignObject(IDragDropObject droppingData, int targetIndex, DragDropOption actions, ModifierFlags modifiers)
{
return(DragDropOption.None);
}
/// <summary>
/// Performs a drag-drop of a non-<see cref="IGalleryItem"/> object from outside this gallery on top of the specified item.
/// </summary>
/// <param name="droppedData">The data object to drop.</param>
/// <param name="targetItem">The target <see cref="IGalleryItem"/> at which the <paramref name="droppedData"/> is being dropped.</param>
/// <param name="actions">The interaction to take.</param>
/// <param name="modifiers">The modifier keys that were pressed at the time of the drop.</param>
/// <returns>The actual interaction on the <paramref name="droppedData"/> that was taken.</returns>
protected virtual DragDropOption PerformDropForeignObject(IDragDropObject droppedData, IGalleryItem targetItem, DragDropOption actions, ModifierFlags modifiers)
{
return DragDropOption.None;
}
/// <summary>
/// Performs a drag-drop of a non-<see cref="IGalleryItem"/> object from outside this gallery to the specified index.
/// </summary>
/// <param name="droppedData">The data object to drop.</param>
/// <param name="targetIndex">The target index at which the <paramref name="droppedData"/> is being dropped.</param>
/// <param name="actions">The interaction to take.</param>
/// <param name="modifiers">The modifier keys that were pressed at the time of the drop.</param>
/// <returns>The actual interaction on the <paramref name="droppedData"/> that was taken.</returns>
protected virtual DragDropOption PerformDropForeignObject(IDragDropObject droppedData, int targetIndex, DragDropOption actions, ModifierFlags modifiers)
{
return DragDropOption.None;
}
/// <summary>
///
/// </summary>
/// <param name="droppedData"></param>
/// <param name="targetItem"></param>
/// <param name="action"></param>
/// <param name="modifiers"></param>
/// <returns></returns>
public override sealed DragDropOption PerformDrop(IDragDropObject droppedData, IGalleryItem targetItem, DragDropOption action, ModifierFlags modifiers)
{
DragDropOption performedAction;
IList<IGalleryItem> droppedItems = ExtractGalleryItemList(droppedData);
if (droppedItems != null)
{
if (_draggedItems == droppedItems)
{
performedAction = PerformDropLocalItems(droppedItems, targetItem, action, modifiers);
}
else
{
performedAction = PerformDropForeignItems(droppedItems, targetItem, action, modifiers);
}
}
else
{
performedAction = PerformDropForeignObject(droppedData, targetItem, action, modifiers);
}
return performedAction;
}
/// <summary>
/// Checks for allowed drag & drop actions involving the specified foreign data and the given target on this component.
/// </summary>
/// <param name="droppingData">The <see cref="IDragDropObject"/> object that encapsulates all forms of the foreign data.</param>
/// <param name="targetItem">The target item that the user is trying to drop on to.</param>
/// <param name="actions"></param>
/// <param name="modifiers">The modifier keys that are being held by the user.</param>
/// <returns>The allowed <see cref="DragDropKind"/> action for this attempted drag & drop operation.</returns>
public override sealed DragDropOption CheckDrop(IDragDropObject droppingData, IGalleryItem targetItem, DragDropOption actions, ModifierFlags modifiers)
{
DragDropOption allowedActions;
IList<IGalleryItem> droppingItems = ExtractGalleryItemList(droppingData);
if (droppingItems != null)
{
if (_draggedItems == droppingItems)
{
allowedActions = CheckDropLocalItems(droppingItems, targetItem, actions, modifiers);
}
else
{
allowedActions = CheckDropForeignItems(droppingItems, targetItem, actions, modifiers);
}
}
else
{
allowedActions = CheckDropForeignObject(droppingData, targetItem, actions, modifiers);
}
return actions & allowedActions;
}