org.eclipse.swt.layout

Class FillLayout

java.lang.Object

org.eclipse.swt.widgets.Layout

org.eclipse.swt.layout.FillLayout

public final class FillLayout
extends Layout

FillLayout is the simplest layout class. It lays out controls in a single row or column, forcing them to be the same size.

Initially, the controls will all be as tall as the tallest control, and as wide as the widest. FillLayout does not wrap, but you can specify margins and spacing. You might use it to lay out buttons in a task bar or tool bar, or to stack checkboxes in a Group. FillLayout can also be used when a Composite only has one child. For example, if a Shell has a single Group child, FillLayout will cause the Group to completely fill the Shell (if margins are 0).

Example code: first a FillLayout is created and its type field is set, and then the layout is set into the Composite. Note that in a FillLayout, children are always the same size, and they fill all available space.

                FillLayout fillLayout = new FillLayout();
                fillLayout.type = SWT.VERTICAL;
                shell.setLayout(fillLayout);
 

See Also:

SWT Example: LayoutExample, Sample code and further information

Field Summary

Fields

Modifier and Type	Field and Description
int	marginHeight marginHeight specifies the number of pixels of vertical margin that will be placed along the top and bottom edges of the layout.
int	marginWidth marginWidth specifies the number of pixels of horizontal margin that will be placed along the left and right edges of the layout.
int	spacing spacing specifies the number of pixels between the edge of one cell and the edge of its neighbouring cell.
int	type type specifies how controls will be positioned within the layout.

Constructor Summary

Constructors

Constructor and Description
FillLayout() Constructs a new instance of this class.
FillLayout(int type) Constructs a new instance of this class given the type.

Method Summary

Modifier and Type	Method and Description
protected Point	computeSize(Composite composite, int wHint, int hHint, boolean flushCache) Computes and returns the size of the specified composite's client area according to this layout.
protected boolean	flushCache(Control control) Instruct the layout to flush any cached values associated with the control specified in the argument control.
protected void	layout(Composite composite, boolean flushCache) Lays out the children of the specified composite according to this layout.
String	toString() Returns a string containing a concise, human-readable description of the receiver.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

type

public int type

type specifies how controls will be positioned within the layout. The default value is HORIZONTAL. Possible values are:

• HORIZONTAL: Position the controls horizontally from left to right
• VERTICAL: Position the controls vertically from top to bottom

marginWidth

public int marginWidth

marginWidth specifies the number of pixels of horizontal margin that will be placed along the left and right edges of the layout. The default value is 0.

Since:

3.0

marginHeight

public int marginHeight

marginHeight specifies the number of pixels of vertical margin that will be placed along the top and bottom edges of the layout. The default value is 0.

Since:

3.0

spacing

public int spacing

spacing specifies the number of pixels between the edge of one cell and the edge of its neighbouring cell. The default value is 0.

Since:

3.0

Constructor Detail

FillLayout

public FillLayout()

Constructs a new instance of this class.

FillLayout

public FillLayout(int type)

Constructs a new instance of this class given the type.

Parameters:

type - the type of fill layout

Since:

2.0

Method Detail

computeSize

protected Point computeSize(Composite composite,
                            int wHint,
                            int hHint,
                            boolean flushCache)

Description copied from class: Layout

Computes and returns the size of the specified composite's client area according to this layout.

This method computes the size that the client area of the composite must be in order to position all children at their preferred size inside the composite according to the layout algorithm encoded by this layout.

When a width or height hint is supplied, it is used to constrain the result. For example, if a width hint is provided that is less than the width of the client area, the layout may choose to wrap and increase height, clip, overlap, or otherwise constrain the children.

Specified by:

computeSize in class Layout

Parameters:

composite - a composite widget using this layout

wHint - width (SWT.DEFAULT for preferred size)

hHint - height (SWT.DEFAULT for preferred size)

flushCache - true means flush cached layout values

Returns:

a point containing the computed size (width, height)

See Also:

Layout.layout(org.eclipse.swt.widgets.Composite, boolean), Control.getBorderWidth(), Control.getBounds(), Control.getSize(), Control.pack(boolean), "computeTrim, getClientArea for controls that implement them"

flushCache

protected boolean flushCache(Control control)

Description copied from class: Layout

Instruct the layout to flush any cached values associated with the control specified in the argument control.

Overrides:

flushCache in class Layout

Parameters:

control - a control managed by this layout

Returns:

true if the Layout has flushed all cached information associated with control

layout

protected void layout(Composite composite,
                      boolean flushCache)

Description copied from class: Layout

Lays out the children of the specified composite according to this layout.

This method positions and sizes the children of a composite using the layout algorithm encoded by this layout. Children of the composite are positioned in the client area of the composite. The position of the composite is not altered by this method.

When the flush cache hint is true, the layout is instructed to flush any cached values associated with the children. Typically, a layout will cache the preferred sizes of the children to avoid the expense of computing these values each time the widget is laid out.

When layout is triggered explicitly by the programmer the flush cache hint is true. When layout is triggered by a resize, either caused by the programmer or by the user, the hint is false.

Specified by:

layout in class Layout

Parameters:

composite - a composite widget using this layout

flushCache - true means flush cached layout values

toString

public String toString()

Returns a string containing a concise, human-readable description of the receiver.

Overrides:

toString in class Object

Returns:

a string representation of the layout