Non-transparent controls on a semi-transparent window

///////////////////////////////////////////////////////////////////////////////
//
//  File:           Design.cs
//
//  Facility:       The unit contains the SkinTooltipDesigner class.
//
//  Abstract:       The class of the designer for the SkinTooltip control.
//
//  Environment:    VC 7.1
//
//  Author:         KB_Soft Group Ltd.
//
///////////////////////////////////////////////////////////////////////////////

using System;
using System.Drawing;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Windows.Forms.Design;
using System.Windows.Forms;


namespace KBSoft.Components.Design
{
	/// <summary>
	/// The class of the designer for the SkinTooltip control.
	/// </summary>
	public class SkinTooltipDesigner : ParentControlDesigner
	{
		#region Fields

		/// <summary>
		/// the filed needed to support hiding of the control in the designer (design time).
		/// </summary>
		private bool isFirstStart = false;

		/// <summary>
		/// the filed defines whether the control is displayed in the designer at the 
		/// given moment.
		/// </summary>
		private bool isControlDisplayed = true;

		/// <summary>
		/// the field saves the location in designer before the DisplayControl property 
		/// is set true.
		/// </summary>
		private Point designTimeLocation;

		/// <summary>
		/// the collection of additional designer's commands.
		/// </summary>
		private DesignerVerbCollection verbs = null;
		/// <summary>
		/// the interface allowing new components to be created in the designer.
		/// </summary>
		private IDesignerHost designerHost = null;
		/// <summary>
		/// the interface allowing the events of changing the selected component to be tracked. 		
		/// </summary>
		private IComponentChangeService componentChangeService = null;
		/// <summary>
		/// the interface alowing the components to be selected.
		/// </summary>
		private ISelectionService selectionService = null;

		/// <summary>
		/// The point where the mouse button was pressed.
		/// </summary>
		private Point pressedPoint = Point.Empty;
		/// <summary>
		/// The label selected in the designer.
		/// </summary>
		private LabelItem selectedItem = null;
		/// <summary>
		/// The point where the mouse button was pressed ( needed to support 
		/// dragging labels with the help of the mouse in the designer )
		/// </summary>
		private bool mousePressed = false;
		/// <summary>
		/// the reference to the control that manages the given class of the designer.
		/// </summary>
		SkinTooltip skinTooltip;

		#endregion

		#region Constructors

		/// <summary>
		/// The constructorof the designer class. Adds the additional "Add label" command
		/// available to the control in the design-time.
		/// </summary>
		public SkinTooltipDesigner()
		{
			this.verbs = new DesignerVerbCollection ();
			this.verbs.Add (new DesignerVerb ("Add label", new EventHandler (this.OnAddLabel)));
		}

			
		#endregion

		#region Methods

		/// <summary>
		/// the method that helps to add the property only for the design-time to the property grid		
		/// </summary>
		/// <param name="properties">the interface of the dictionary where the needed properties will be added.</param>
		protected override void PreFilterProperties ( System.Collections.IDictionary properties )
		{
			base.PreFilterProperties (properties);

			// Create design-time-only property "DisplayControl" entry and add it to 
			// the  Property Browser's "Design" category.
			properties ["DisplayControl"] = TypeDescriptor.CreateProperty (typeof (SkinTooltipDesigner),
				"DisplayControl", typeof (bool), CategoryAttribute.Design,
				DesignOnlyAttribute.Yes);

		}

		/// <summary>
		/// The function that is called when creating the designer of the component.
		/// </summary>
		/// <param name="component">the reference to the component that will be served by the designer.</param>
		public override void Initialize( IComponent component )
		{
			base.Initialize (component);
			this.isFirstStart = true;

			this.designerHost = this.GetService (typeof(IDesignerHost))as
				IDesignerHost;

			this.selectionService = this.GetService (typeof(ISelectionService))
				as ISelectionService;

			this.componentChangeService = this.GetService (typeof
				(IComponentChangeService))as IComponentChangeService;

			this.Control.MouseDown +=new MouseEventHandler(Control_MouseDown);
			this.Control.MouseUp +=new MouseEventHandler(Control_MouseUp);
			this.Control.MouseMove +=new MouseEventHandler(Control_MouseMove);

			if (this.selectionService != null)
			{
				this.selectionService.SelectionChanged +=new EventHandler(selectionService_SelectionChanged);
			}

			if (this.componentChangeService != null)
			{
				this.componentChangeService.ComponentRemoving +=new ComponentEventHandler(componentChangeService_ComponentRemoving);
			}     

			skinTooltip = this.Control as SkinTooltip;

			this.DrawGrid = false;
		}

		/// <summary>
		/// The handler method for clicking the "Add label" command in design-time.
		/// </summary>
		/// <param name="sender">The object that invoked the event.</param>
		/// <param name="e">the event's arguments.</param>
		protected void OnAddLabel ( object sender, EventArgs e )
		{

			LabelItem item = this.designerHost.CreateComponent( typeof(LabelItem) ) as LabelItem;
			item.Parent = skinTooltip;
			skinTooltip.Labels.Add(item);

			item.LabelText = "New label";

			Random rand = new Random ();            
			item.LabelRect = new Rectangle (rand.Next (skinTooltip.Width - 55), rand.Next (skinTooltip.Height - 15), 55, 15);
		}

		/// <summary>
		/// The handler of clicking the control by mouse.
		/// </summary>
		/// <param name="sender">the object that invoked the event.</param>
		/// <param name="e">the event's parameters.</param>
		private void Control_MouseDown( object sender, MouseEventArgs e )
		{

			foreach( LabelItem item in skinTooltip.Labels )
			{
				if( item.LabelRect.Contains( new Point( e.X, e.Y ) ) )
				{
					mousePressed = true;

					UnselectAllItems();

					this.selectedItem = item;
					SetSelectComponent(item);
					
					this.pressedPoint = new Point( e.X, e.Y );
					this.selectedItem.Selected = true;
				}
			}

		}

		/// <summary>
		/// Handling the event of releasing the left mouse button.
		/// </summary>
		/// <param name="sender">the object that sent the message.</param>
		/// <param name="e">the message parameters.</param>
		private void Control_MouseUp(object sender, MouseEventArgs e)
		{
			mousePressed = false;
		}

		/// <summary>
		/// The function that makes the component selected in the designer.
		/// </summary>
		/// <param name="comp">the component to be selected.</param>
		private void SetSelectComponent (Component comp)
		{
			if (comp == null)
				return;

			Component[]items = new Component[1];
			items[0] = comp;
			if (this.selectionService != null)
				this.selectionService.SetSelectedComponents (items);
		}

		/// <summary>
		/// The function determines whether the mouse click should be handled by the designer.
		/// </summary>
		/// <param name="point">the point that was ckicked.</param>
		/// <returns>returns true if the message should be handled by the designer.</returns>
		protected override bool GetHitTest( Point point )
		{
			Point tpPoint = skinTooltip.PointToClient (point);

			foreach( LabelItem item in skinTooltip.Labels )
				if( item.LabelRect.Contains(tpPoint) )
					return true;

			return false;
		}


		/// <summary>
		/// the handler of the message of mooving the mouse on the control.
		/// </summary>
		/// <param name="sender">the object invoked the event.</param>
		/// <param name="e">the event's parameters.</param>
		private void Control_MouseMove( object sender, MouseEventArgs e )
		{

			Rectangle current;
			Rectangle old;

			if( selectedItem != null && mousePressed )
			{
				current = selectedItem.LabelRect;
				old = current;

				current.X += e.X - pressedPoint.X;
				current.Y += e.Y - pressedPoint.Y;

				selectedItem.LabelRect = current;

				pressedPoint = new Point( e.X, e.Y );
				PropertyDescriptor pd = TypeDescriptor.GetProperties(selectedItem).Find("LabelRect", false);
				
				componentChangeService.OnComponentChanged( selectedItem, pd, old, current );	
			}

		}

		/// <summary>
		/// the handler of the message of changing the selected component.
		/// </summary>
		/// <param name="sender">the object invoked the event.</param>
		/// <param name="e">the event's parameters.</param>
		private void selectionService_SelectionChanged( object sender, EventArgs e )
		{
			LabelItem item =this.selectionService.PrimarySelection as LabelItem;

			if( item != null )
			{
				UnselectAllItems();

				item.Selected = true;
			}

		}

		/// <summary>
		/// The function unselecting all Labels in the SkinTooltip control.
		/// </summary>
		private void UnselectAllItems()
		{
			foreach( LabelItem item in skinTooltip.Labels )
				item.Selected = false;
		}

		/// <summary>
		/// The handler of the message of removing the component from the designer.
		/// It performs the label removal from the control.
		/// </summary>
		/// <param name="sender">the object invoked the event.</param>
		/// <param name="e">the event's parameters</param>
		private void componentChangeService_ComponentRemoving( object sender, ComponentEventArgs e )
		{
			LabelItem item = e.Component as LabelItem;

			if( item != null )
			{
				this.skinTooltip.Labels.Remove( item );
				skinTooltip.Invalidate();
				skinTooltip.Update();
			}
		}

		#endregion

		#region Properties

		/// <summary>
		/// the property returns the collection of additional designer's commands.
		/// </summary>
		public override DesignerVerbCollection Verbs
		{
			get
			{
				return this.verbs;
			}
		}

		/// <summary>
		/// the property defining whether to display SkinTooltip on the form's surface 
		/// in design time.
		/// </summary>
		public bool DisplayControl
		{
			get{ return this.isControlDisplayed; }
			set
			{
				if(this.isFirstStart)
					isControlDisplayed = value;
				else
					if(isControlDisplayed == value)
						return;
				
				if ( !value )
				{
					this.designTimeLocation = this.Control.Location;
					this.Control.Location = new Point(-this.Control.Width, -this.Control.Height);
					
				}
				else
				{
					if( !this.designTimeLocation.IsEmpty )
						this.Control.Location = this.designTimeLocation;
					else
						this.Control.Location = new Point(100,100);
				}

			}
		}

		#endregion
	}

}