mono/mcs/class/Managed.Windows.Forms/System.Windows.Forms.Layout/DefaultLayout.cs

//
// DefaultLayout.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 ([email protected])
//

using System;
using System.Drawing;

namespace System.Windows.Forms.Layout
{
	class DefaultLayout : LayoutEngine
	{
		public override bool Layout (object container, LayoutEventArgs args)
		{
			Control parent = container as Control;

			Control child;
			AnchorStyles anchor;
			Rectangle space;

			space = parent.DisplayRectangle;

			// Deal with docking; go through in reverse, MS docs say that lowest Z-order is closest to edge
			Control[] controls = parent.Controls.GetAllControls ();
			for (int i = controls.Length - 1; i >= 0; i--) {
				child = controls[i];

				if (!child.Visible)
					continue;

				switch (child.Dock) {
				case DockStyle.None:
					// Do nothing
					break;

				case DockStyle.Left:
					child.SetImplicitBounds (space.Left, space.Y, child.Width, space.Height);
					space.X += child.Width;
					space.Width -= child.Width;
					break;

				case DockStyle.Top:
					child.SetImplicitBounds (space.Left, space.Y, space.Width, child.Height);
					space.Y += child.Height;
					space.Height -= child.Height;
					break;

				case DockStyle.Right:
					child.SetImplicitBounds (space.Right - child.Width, space.Y, child.Width, space.Height);
					space.Width -= child.Width;
					break;

				case DockStyle.Bottom:
					child.SetImplicitBounds (space.Left, space.Bottom - child.Height, space.Width, child.Height);
					space.Height -= child.Height;
					break;
				}
			}

			for (int i = controls.Length - 1; i >= 0; i--) {
				child = controls[i];

				if (child.Visible && (child.Dock == DockStyle.Fill)) {
					child.SetBounds (space.Left, space.Top, space.Width, space.Height);
				}
			}

			space = parent.DisplayRectangle;

			for (int i = 0; i < controls.Length; i++) {
				int left;
				int top;
				int width;
				int height;

				child = controls[i];

				// If the control is docked we don't need to do anything
				if (child.Dock != DockStyle.None) {
					continue;
				}

				anchor = child.Anchor;

				left = child.Left;
				top = child.Top;
				width = child.Width;
				height = child.Height;

				if ((anchor & AnchorStyles.Left) != 0) {
					if ((anchor & AnchorStyles.Right) != 0) {
						width = space.Width - child.dist_right - left;
					}
					else {
						; // Left anchored only, nothing to be done
					}
				}
				else if ((anchor & AnchorStyles.Right) != 0) {
					left = space.Width - child.dist_right - width;
				}
				else {
					// left+=diff_width/2 will introduce rounding errors (diff_width removed from svn after r51780)
					// This calculates from scratch every time:
					left = left + (space.Width - (left + width + child.dist_right)) / 2;
				}

				if ((anchor & AnchorStyles.Top) != 0) {
					if ((anchor & AnchorStyles.Bottom) != 0) {
						height = space.Height - child.dist_bottom - top;
					}
					else {
						; // Top anchored only, nothing to be done
					}
				}
				else if ((anchor & AnchorStyles.Bottom) != 0) {
					top = space.Height - child.dist_bottom - height;
				}
				else {
					// top += diff_height/2 will introduce rounding errors (diff_height removed from after r51780)
					// This calculates from scratch every time:
					top = top + (space.Height - (top + height + child.dist_bottom)) / 2;
				}

				// Sanity
				if (width < 0) {
					width = 0;
				}

				if (height < 0) {
					height = 0;
				}

				child.SetBounds (left, top, width, height);
			}

			return false;
		}
	}
}