/// <summary>
/// Creates a model to represent a control in the toolbox.
/// </summary>
/// <param name="controlData">The data of the control to be modeled.</param>
/// <returns>Returns a new instance of the model for the control.</returns>
private ControlTreeNodeModel CreateControlModel(ControlData controlData)
{
var controlModel = new ControlTreeNodeModel(controlData);
controlModels[controlData.FullName] = controlModel;
return(controlModel);
}
/// <summary>
/// This method is called when a drag operation completes by dropping over the simulated designer surface.
/// </summary>
/// <param name="sender">The sender.</param>
/// <param name="e">The event args.</param>
private void OnDesignerDrop(object sender, DragEventArgs e)
{
// Lookup the dropped control (only a single item is supported)
ControlTreeNodeModel controlModel = CustomTreeListBoxItemAdapter
.GetDraggedModels(e.Data, treeListBox)
.OfType <ControlTreeNodeModel>()
.FirstOrDefault();
// Here is where the dropped item would be processed. For this demo, only a message will be displayed.
if (controlModel is null)
{
MessageBox.Show($"The dropped item is not supported by this designer.", "UI Designer", MessageBoxButton.OK, MessageBoxImage.Warning);
}
else
{
MessageBox.Show($"Add the following control to the designer:\r\n\r\n\t{controlModel.FullName}", "UI Designer", MessageBoxButton.OK, MessageBoxImage.Information);
}
}
/// <summary>
/// Tries to get the category and control models for the specified item.
/// </summary>
/// <param name="toolboxControl">The <see cref="TreeListBox"/> control.</param>
/// <param name="item">The item to examine.</param>
/// <param name="categoryModel">The resulting <see cref="CategoryTreeNodeModel"/>.</param>
/// <param name="controlModel">The resulting <see cref="ControlTreeNodeModel"/>.</param>
/// <returns>
/// <c>true</c> if results were found; otherwise, <c>false</c>.
/// </returns>
private bool TryGetModelsFromItem(TreeListBox toolboxControl, object item, out CategoryTreeNodeModel categoryModel, out ControlTreeNodeModel controlModel)
{
if (item is ControlTreeNodeModel localControlModel)
{
controlModel = localControlModel;
return(TryGetCategory(toolboxControl, controlModel, out categoryModel));
}
else if (item is EmptyPlaceholderTreeNodeModel emptyPlaceholderModel)
{
controlModel = null;
return(TryGetCategory(toolboxControl, emptyPlaceholderModel, out categoryModel));
}
else if (item is CategoryTreeNodeModel localCategoryModel)
{
controlModel = null;
categoryModel = localCategoryModel;
return(true);
}
categoryModel = null;
controlModel = null;
return(false);
}