com.codename1.ui.layouts

Class BoxLayout

java.lang.Object

com.codename1.ui.layouts.Layout

com.codename1.ui.layouts.BoxLayout

public class BoxLayout
extends Layout

Layout manager that places elements in a row (X_AXIS) or column (Y_AXIS) according to box orientation. Box is a very simple and predictable layout that serves as the "workhorse" of component lists in Codename One
You can create a box layout Y UI using syntax such as this

This can also be expressed with more terse syntax e.g. an X axis layout like this:

The BoxLayout keeps the preferred size of its destination orientation and scales elements on the other axis. Specifically X_AXIS will keep the preferred width of the component while growing all the components vertically to match in size. Its Y_AXIS counterpart keeps the preferred height while growing the components horizontally.
This behavior is very useful since it allows elements to align as they would all have the same size.

In some cases the growing behavior in the X axis is undesired, for these cases we can use the X_AXIS_NO_GROW variant.

FlowLayout vs. BoxLayout.X_AXIS/X_AXIS_NO_GROW

There are quite a few differences between FlowLayout and BoxLayout. When it doesn't matter to you we tend to recommend BoxLayout as it acts more consistently in all situations since its far simpler. Another advantage of BoxLayout is the fact that it grows and thus aligns nicely.

Field Summary

Fields

Modifier and Type	Field and Description
static int	X_AXIS Horizontal layout where components are arranged from left to right
static int	X_AXIS_NO_GROW Horizontal layout where components are arranged from left to right but don't grow vertically beyond their preferred size
static int	Y_AXIS Vertical layout where components are arranged from top to bottom
static int	Y_AXIS_BOTTOM_LAST Same as Y_AXIS with a special case for the last component.

Constructor Summary

Constructors

Constructor and Description
BoxLayout(int axis) Creates a new instance of BoxLayout

Method Summary

Modifier and Type	Method and Description
static Container	encloseX(Component... cmps) The equivalent of Container.enclose() with a box layout X
static Container	encloseXCenter(Component... cmps) The equivalent of Container.enclose() with a box layout X, with center alignment.
static Container	encloseXNoGrow(Component... cmps) The equivalent of Container.enclose() with a box layout X no grow option
static Container	encloseXRight(Component... cmps) The equivalent of Container.enclose() with a box layout X, with right alignment.
static Container	encloseY(Component... cmps) The equivalent of Container.enclose() with a box layout Y
static Container	encloseYBottom(Component... cmps) The equivalent of Container.enclose() with a box layout Y, with bottom alignment.
static Container	encloseYBottomLast(Component... cmps) The equivalent of Container.enclose() with a box layout Y in bottom last mode
static Container	encloseYCenter(Component... cmps) The equivalent of Container.enclose() with a box layout Y, with center alignment.
boolean	equals(Object o) Indicates whether some other object is "equal to" this one.
int	getAlign() Gets the alignment of this layout.
int	getAxis() Returns the layout axis x/y
Dimension	getPreferredSize(Container parent) Returns the container preferred size
void	layoutContainer(Container parent) Layout the given parent container children
void	setAlign(int align) Sets the alignment of this layout.
String	toString() Returns a string representation of the object.
static BoxLayout	x() Shorthand for new BoxLayout(BoxLayout.X_AXIS)
static BoxLayout	xCenter() Creates a new layout with X_AXIS, and align center.
static BoxLayout	xRight() Creates a new layout with X_AXIS, and align right.
static BoxLayout	y() Shorthand for new BoxLayout(BoxLayout.Y_AXIS)
static BoxLayout	yBottom() Creates a new layout with Y_AXIS, and align bottom.
static BoxLayout	yCenter() Creates a new layout with Y_AXIS, and align center.
static BoxLayout	yLast() Shorthand for new BoxLayout(BoxLayout.Y_AXIS_BOTTOM_LAST)

Methods inherited from class com.codename1.ui.layouts.Layout

addLayoutComponent, cloneConstraint, getChildrenInTraversalOrder, getComponentConstraint, hashCode, isConstraintTracking, isOverlapSupported, obscuresPotential, overridesTabIndices, removeLayoutComponent, updateTabIndices

Methods inherited from class java.lang.Object

clone, getClass, notify, notifyAll, wait, wait, wait

Field Detail

X_AXIS

public static final int X_AXIS

Horizontal layout where components are arranged from left to right

See Also:

Constant Field Values

Y_AXIS

public static final int Y_AXIS

Vertical layout where components are arranged from top to bottom

See Also:

Constant Field Values

X_AXIS_NO_GROW

public static final int X_AXIS_NO_GROW

Horizontal layout where components are arranged from left to right but don't grow vertically beyond their preferred size

See Also:

Constant Field Values

Y_AXIS_BOTTOM_LAST

public static final int Y_AXIS_BOTTOM_LAST

Same as Y_AXIS with a special case for the last component. The last component is glued to the end of the available space

See Also:

Constant Field Values

Constructor Detail

BoxLayout

public BoxLayout(int axis)

Creates a new instance of BoxLayout

Parameters:

axis - the axis to lay out components along. Can be: BoxLayout.X_AXIS or BoxLayout.Y_AXIS

Method Detail

y

public static BoxLayout y()

Shorthand for new BoxLayout(BoxLayout.Y_AXIS)

Returns:

a new Y axis BoxLayout

yLast

public static BoxLayout yLast()

Shorthand for new BoxLayout(BoxLayout.Y_AXIS_BOTTOM_LAST)

Returns:

a new Y bottom last axis BoxLayout

yCenter

public static BoxLayout yCenter()

Creates a new layout with Y_AXIS, and align center.

Returns:

BoxLayout with center alignment on Y_AXIS.

Since:

7.0

yBottom

public static BoxLayout yBottom()

Creates a new layout with Y_AXIS, and align bottom.

Returns:

BoxLayout with bottom alignment on Y_AXIS.

Since:

7.0

x

public static BoxLayout x()

Shorthand for new BoxLayout(BoxLayout.X_AXIS)

Returns:

a new X axis BoxLayout

xCenter

public static BoxLayout xCenter()

Creates a new layout with X_AXIS, and align center.

Returns:

BoxLayout with center alignment on X_AXIS.

Since:

7.0

xRight

public static BoxLayout xRight()

Creates a new layout with X_AXIS, and align right.

Returns:

BoxLayout with right alignment on X_AXIS.

Since:

7.0

setAlign

public void setAlign(int align)

Sets the alignment of this layout. By default Y_AXIS aligns top, and X_AXIS aligns left (RTL-aware). You can specify an align value of Component.CENTER to align items vertically centered (for Y_AXIS), and horizontally centered (for X_AXIS), of Component.BOTTOM to align vertically bottom (Y_AXIS), and Component.RIGHT to align right (RTL-aware), for X_AXIS.

Parameters:

align - One of Component.CENTER, Component.BOTTOM, Component.RIGHT, to adjust the alignment of children.

Since:

7.0

getAlign

public int getAlign()

Gets the alignment of this layout. By default Y_AXIS aligns top, and X_AXIS aligns left (RTL-aware). You can specify an align value of Component.CENTER to align items vertically centered (for Y_AXIS), and horizontally centered (for X_AXIS), of Component.BOTTOM to align vertically bottom (Y_AXIS), and Component.RIGHT to align right (RTL-aware), for X_AXIS.

Returns:

The alignment.

Since:

7.0

layoutContainer

public void layoutContainer(Container parent)

Layout the given parent container children

Specified by:

layoutContainer in class Layout

Parameters:

parent - the given parent container

getPreferredSize

public Dimension getPreferredSize(Container parent)

Returns the container preferred size

Specified by:

getPreferredSize in class Layout

Parameters:

parent - the parent container

Returns:

the container preferred size

getAxis

public int getAxis()

Returns the layout axis x/y

Returns:

the layout axis

toString

public String toString()

Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method. The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of: getClass().getName() + '@' + Integer.toHexString(hashCode())

Overrides:

toString in class Object

equals

public boolean equals(Object o)

Indicates whether some other object is "equal to" this one. The equals method implements an equivalence relation: It is reflexive: for any reference value x, x.equals(x) should return true. It is symmetric: for any reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true. It is transitive: for any reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true. It is consistent: for any reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false, provided no information used in equals comparisons on the object is modified. For any non-null reference value x, x.equals(null) should return false. The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any reference values x and y, this method returns true if and only if x and y refer to the same object (x==y has the value true).

Overrides:

equals in class Layout

encloseY

public static Container encloseY(Component... cmps)

The equivalent of Container.enclose() with a box layout Y

Parameters:

cmps - the set of components

Returns:

the newly created container

encloseYCenter

public static Container encloseYCenter(Component... cmps)

The equivalent of Container.enclose() with a box layout Y, with center alignment.

Parameters:

cmps - the set of components

Returns:

the newly created container

Since:

7.0

encloseYBottom

public static Container encloseYBottom(Component... cmps)

The equivalent of Container.enclose() with a box layout Y, with bottom alignment.

Parameters:

cmps - the set of components

Returns:

the newly created container

Since:

7.0

encloseYBottomLast

public static Container encloseYBottomLast(Component... cmps)

The equivalent of Container.enclose() with a box layout Y in bottom last mode

Parameters:

cmps - the set of components

Returns:

the newly created container

encloseX

public static Container encloseX(Component... cmps)

The equivalent of Container.enclose() with a box layout X

Parameters:

cmps - the set of components

Returns:

the newly created container

encloseXNoGrow

public static Container encloseXNoGrow(Component... cmps)

The equivalent of Container.enclose() with a box layout X no grow option

Parameters:

cmps - the set of components

Returns:

the newly created container

encloseXCenter

public static Container encloseXCenter(Component... cmps)

The equivalent of Container.enclose() with a box layout X, with center alignment.

Parameters:

cmps - the set of components

Returns:

the newly created container

Since:

7.0

encloseXRight

public static Container encloseXRight(Component... cmps)

The equivalent of Container.enclose() with a box layout X, with right alignment.

Parameters:

cmps - the set of components

Returns:

the newly created container

Since:

7.0