Class LayoutItemBase

Represents a non-control based layout component.

Inheritance

System.Object

LayoutItemBase

Implements

IProvideLayoutInformation

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: Syncfusion.Windows.Forms.Tools

Assembly: Syncfusion.Shared.Base.dll

Syntax

public abstract class LayoutItemBase : IProvideLayoutInformation

Remarks

Derive your non-control based components from this class if you want them to participate in the layout management.

You can add such components to the manager using the same methods as the control derived classes. You can pass a LayoutItemBase derived class to any method that expects a control type argument since the LayoutItemBase has an implicit type-conversion operator that can convert itself to a control. In VB, use the ToControl() method to convert this instance to a control.

In your derived class, you can find out the size set by the layout manager through the Bounds property and the visibility through the Visible property (listening for the BoundsChanged event should also help). You should also provide the preferred size and minimum size of your component through the PreferredSize and MinimumSize overrides.

Examples

This first example shows a sample LayoutItemBase derived class:

public class MyRectangle : LayoutItemBase
{
	public static Size PrefSize = new Size(0, 0);
	protected Control parent;
	protected Color color;
	protected string text;
	public MyRectangle(Control parent, Color color, string text)
	{
		this.parent = parent;
		this.color = color;
		this.text = text;
	}
	public void OnPaint( PaintEventArgs e)
	{
		e.Graphics.FillRectangle(new SolidBrush(color), this.Bounds);
		StringFormat sf = new StringFormat();
		sf.Alignment = StringAlignment.Center;
		sf.LineAlignment = StringAlignment.Center;
		RectangleF r = new RectangleF(Bounds.Left, Bounds.Top,
			Bounds.Width, Bounds.Height);
		e.Graphics.DrawString(text, Control.DefaultFont, SystemBrushes.ControlText, r, sf);
	}
	// This override is a good place to repaint.
	// Or you can listen to BoundsChanged event in LayoutItemBase.
	protected override void OnBoundsChanged()
	{
		parent.Invalidate(new Rectangle(0, 0, this.parent.Width, this.parent.Height));
	}

	public override System.Drawing.Size MinimumSize
	{
		get	{	return MyRectangle.PrefSize;	}
	}

	public override System.Drawing.Size PreferredSize
	{
		get	
		{
			return MyRectangle.PrefSize;
		}
	}
}

The above class can then participate in layout as follows. The example assumes that there is a GridBagLayout manager that is already bound to a container.

	private void Form1_Load(object sender, System.EventArgs e)
	{
		this.SuspendLayout();
		// Current layout manager (Update every time you change the manager)
	// Layout Component 1:
	this.myRect1 = new MyRectangle(this.gridBagLayout1.ContainerControl, Color.FromArgb(133, 191, 117), &quot;Paint Area 1&quot;);
	this.myRect1.Bounds = new Rectangle(10, 10, 80, 20);
	this.myRect1.Visible = true;

	// Layout Component 2:
	this.myRect2 = new MyRectangle(this.gridBagLayout1.ContainerControl, Color.FromArgb(222, 100, 19), &quot;Paint Area 2&quot;);
	this.myRect2.Bounds = new Rectangle(10, 40, 80, 20);
	this.myRect2.Visible = true;

	// Layout Component 3:
	this.myRect3 = new MyRectangle(this.gridBagLayout1.ContainerControl, Color.FromArgb(196, 214, 233), &quot;Paint Area 3&quot;);
	this.myRect3.Bounds = new Rectangle(10, 70, 80, 20);
	this.myRect3.Visible = true;


	// Sample GridBagConstraints:
	GridBagConstraints gbc1 = new GridBagConstraints();
	GridBagConstraints gbc2 = new GridBagConstraints();
	GridBagConstraints gbc3 = new GridBagConstraints();

	gbc1.Fill = FillType.Both;
	gbc1.WeightX = 0.2;
	gbc1.WeightY = 0.5;
	gbc1.GridPosX = 0;
	gbc1.GridPosY = 0;

	gbc2.Fill = FillType.Both;
	gbc2.WeightX = 0.2;
	gbc2.WeightY = 0.5;
	gbc2.GridPosX = 1;
	gbc2.GridPosY = 0;

	gbc3.Fill = FillType.Both;
	gbc3.WeightX = 0.4;
	gbc3.WeightY = 0.5;
	gbc3.GridPosX = 0;
	gbc3.GridPosY = 1;
	gbc3.CellSpanX = 2;

	// Add all the components that are to participate in Layout Management.

	// For GridBagLayouts pass gbcs for GridBagLayouts:
	this.gridBagLayout1.SetConstraints(this.myRect1.ToControl(), gbc1);	
	this.gridBagLayout1.SetConstraints(this.myRect2.ToControl(), gbc2);
	this.gridBagLayout1.SetConstraints(this.myRect3.ToControl(), gbc3);

	this.ResumeLayout(true);
}</code></pre>

Constructors

LayoutItemBase()

Creates an instance of the LayoutItemBase.

Declaration

protected LayoutItemBase()

Fields

boundsChangingFromOutsideFramework

Declaration

protected bool boundsChangingFromOutsideFramework

Field Value

Type
System.Boolean

Properties

Bounds

Gets / sets the bounds of the component in the corresponding layout manager's ContainerControl's client co-ordinates.

Declaration

public Rectangle Bounds { get; set; }

Property Value

Type	Description
System.Drawing.Rectangle	The rectangle within the parent control, in client co-ordinates.

LayoutManager

Declaration

protected LayoutManager LayoutManager { set; }

Property Value

Type
LayoutManager

MinimumSize

Returns the minimum size of the component.

Declaration

public abstract Size MinimumSize { get; }

Property Value

Type
System.Drawing.Size

PreferredSize

Returns the preferred size of the component.

Declaration

public abstract Size PreferredSize { get; }

Property Value

Type
System.Drawing.Size

Visible

Indicates whether the component should be drawn visible.

Declaration

public bool Visible { get; set; }

Property Value

Type	Description
System.Boolean	True for visible; False for hidden.

Methods

Control_BoundsChanged(Object, EventArgs)

Declaration

public void Control_BoundsChanged(object sender, EventArgs e)

Parameters

Type	Name	Description
System.Object	sender
System.EventArgs	e

OnBoundsChanged()

Declaration

protected virtual void OnBoundsChanged()

ToControl()

Returns the place holder control corresponding to this LayoutItemBase that lets the LayoutItemBase participate in the LayoutManager framework.

Declaration

public Control ToControl()

Returns

Type	Description
System.Windows.Forms.Control	The corresponding place holder control.

Events

BoundsChanged

Called when the Bounds property changes.

Declaration

public event EventHandler BoundsChanged

Event Type

Type
System.EventHandler

Operators

Implicit(LayoutItemBase to Control)

Returns the place holder control corresponding to the LayoutItemBase that lets the LayoutItemBase participate in the LayoutManager framework.

Declaration

public static implicit operator Control(LayoutItemBase lm)

Parameters

Type	Name	Description
LayoutItemBase	lm	The LayoutItemBase object.

Returns

Type	Description
System.Windows.Forms.Control	The corresponding place holder control.

Implements

IProvideLayoutInformation