linux-packaging-mono/mcs/class/Managed.Windows.Forms/System.Windows.Forms/FlowLayoutPanel.cs

//
// FlowLayoutPanel.cs
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
// Copyright (c) 2006 Jonathan Pobst
//
// Authors:
//	Jonathan Pobst (monkey@jpobst.com)
//

using System.Windows.Forms.Layout;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Drawing;

namespace System.Windows.Forms
{
	[ComVisibleAttribute (true)]
	[ClassInterfaceAttribute (ClassInterfaceType.AutoDispatch)]
	[ProvideProperty ("FlowBreak", typeof (Control))]
	[DefaultProperty ("FlowDirection")]
	[Docking (DockingBehavior.Ask)]
	[Designer ("System.Windows.Forms.Design.FlowLayoutPanelDesigner, " + Consts.AssemblySystem_Design, "System.ComponentModel.Design.IDesigner")]
	public class FlowLayoutPanel : Panel, IExtenderProvider
	{
		private FlowLayoutSettings settings;

		public FlowLayoutPanel () : base ()
		{
			CreateDockPadding ();
		}

		#region Properties
		[Localizable (true)]
		[DefaultValue (FlowDirection.LeftToRight)]
		public FlowDirection FlowDirection {
			get { return LayoutSettings.FlowDirection; }
			set { LayoutSettings.FlowDirection = value; }
		}

		[LocalizableAttribute (true)]
		[DefaultValue (true)]
		public bool WrapContents {
			get { return LayoutSettings.WrapContents; }
			set { LayoutSettings.WrapContents = value; }
		}

		public override LayoutEngine LayoutEngine {
			get { return this.LayoutSettings.LayoutEngine; }
		}

		internal FlowLayoutSettings LayoutSettings {
			get { 
				if (this.settings == null)
					this.settings = new FlowLayoutSettings (this);
					
				return this.settings;
			}
		}
		#endregion

		#region Public Methods
		[DefaultValue (false)]
		[DisplayName ("FlowBreak")]
		public bool GetFlowBreak (Control control)
		{
			return LayoutSettings.GetFlowBreak (control);
		}

		[DisplayName ("FlowBreak")]
		public void SetFlowBreak (Control control, bool value)
		{
			LayoutSettings.SetFlowBreak (control, value);
		}		
		#endregion
		
		#region IExtenderProvider Members
		bool IExtenderProvider.CanExtend (object obj)
		{
			if (obj is Control)
				if ((obj as Control).Parent == this)
					return true;

			return false;
		}
		#endregion

		#region Internal Methods
		internal override void CalculateCanvasSize (bool canOverride)
		{
			if (canOverride)
				canvas_size = ClientSize;
			else
				base.CalculateCanvasSize (canOverride);
		}

               protected override void OnLayout (LayoutEventArgs levent)
               {
                       base.OnLayout (levent);

                       // base.OnLayout() calls CalculateCanvasSize(true) in which we just set the canvas to
                       // clientsize so we could re-layout everything according to the flow.
                       // This time we want to actually calculate the canvas.
                       CalculateCanvasSize (false);
                       if (AutoSize && (canvas_size.Width > ClientSize.Width || canvas_size.Height > ClientSize.Height)) {
                               ClientSize = canvas_size;
                       }
                       AdjustFormScrollbars (AutoScroll);
               }
		
		internal override Size GetPreferredSizeCore (Size proposedSize)
		{
			int width = 0;
			int height = 0;
			bool horizontal = FlowDirection == FlowDirection.LeftToRight || FlowDirection == FlowDirection.RightToLeft;
			if (!WrapContents || (horizontal && proposedSize.Width == 0) || (!horizontal && proposedSize.Height == 0)) {
				foreach (Control control in Controls) {
					Size control_preferred_size;
					if (control.AutoSize)
						control_preferred_size = control.PreferredSize;
					else
						control_preferred_size = control.Size;
					Padding control_margin = control.Margin;
					if (horizontal) {
						width += control_preferred_size.Width + control_margin.Horizontal;
						height = Math.Max (height, control_preferred_size.Height + control_margin.Vertical);
					} else {
						height += control_preferred_size.Height + control_margin.Vertical;
						width = Math.Max (width, control_preferred_size.Width + control_margin.Horizontal);
					}
				}
			} else {
				int size_in_flow_direction = 0;
				int size_in_other_direction = 0;
				int increase;
				foreach (Control control in Controls) {
					Size control_preferred_size;
					if (control.AutoSize)
						control_preferred_size = control.PreferredSize;
					else
						control_preferred_size = control.ExplicitBounds.Size;
					Padding control_margin = control.Margin;
					if (horizontal) {
						increase = control_preferred_size.Width + control_margin.Horizontal;
						if (size_in_flow_direction != 0 && size_in_flow_direction + increase >= proposedSize.Width) {
							width = Math.Max (width, size_in_flow_direction);
							size_in_flow_direction = 0;
							height += size_in_other_direction;
							size_in_other_direction = 0;
						}
						size_in_flow_direction += increase;
						size_in_other_direction = Math.Max (size_in_other_direction, control_preferred_size.Height + control_margin.Vertical);
					} else {
						increase = control_preferred_size.Height + control_margin.Vertical;
						if (size_in_flow_direction != 0 && size_in_flow_direction + increase >= proposedSize.Height) {
							height = Math.Max (height, size_in_flow_direction);
							size_in_flow_direction = 0;
							width += size_in_other_direction;
							size_in_other_direction = 0;
						}
						size_in_flow_direction += increase;
						size_in_other_direction = Math.Max (size_in_other_direction, control_preferred_size.Width + control_margin.Horizontal);
					}
				}
				if (horizontal) {
					width = Math.Max (width, size_in_flow_direction);
					height += size_in_other_direction;
				} else {
					height = Math.Max (height, size_in_flow_direction);
					width += size_in_other_direction;
				}
			}
			return new Size (width, height);
		}
		#endregion
	}
}