Class UIFixedFlowLayout

public class UIFixedFlowLayout extends UILayoutManager
{
  // Fields
  public static final int CENTER;
  public static final int LEFT;
  public static final int RIGHT;

  // Constructors
  public UIFixedFlowLayout();
  public UIFixedFlowLayout(int hgap, int vgap);
  public UIFixedFlowLayout(int hgap, int vgap, int alignment);

  // Methods
  protected Dimension computeUnitDimension(IUIContainer target,
        boolean min);
  public int getAlignment();
  public Dimension getMinimumSize(IUIContainer target);
  public Dimension getPreferredSize(IUIContainer target);
  public boolean isOverlapping();
  public boolean isWidthRelative();
  public void layout(IUIContainer target, Rectangle bounds);
  public IUIComponent navigate(IUIContainer cont,
        IUIComponent comp, int dir, boolean keyable);
  public void setAlignment(int alignment);
}

This class implements a fixed-width flow layout manager. UIFixedFlowLayout lays out components by row, using a fixed width for each component. The fixed width is the largest of the preferred widths of each component.

UIFixedFlowLayout is the default layout manager for UIBand.

UILayoutManager
  |
  +--UIFixedFlowLayout

Constructors

UIFixedFlowLayout

public UIFixedFlowLayout();

Creates a fixed-width flow layout manager.

Remarks:

By default, the horizontal and vertical gaps (used for spacing around the container's components) are 5 pixels each. The components are left-aligned within the container.

UIFixedFlowLayout

public UIFixedFlowLayout(int hgap, int vgap);

Creates a fixed-width flow layout manager with the specified horizontal and vertical gaps.

Parameter	Description
hgap	The number of pixels used for horizontal spacing between the components.
vgap	The number of pixels used for vertical spacing above and below the components.

Remarks:

By default, the components are left-aligned within the container.

UIFixedFlowLayout

public UIFixedFlowLayout(int hgap, int vgap, int alignment);

Creates a fixed-width flow layout manager with the specified alignment, and horizontal and vertical gaps.

Parameter	Description
hgap	The number of pixels used for horizontal spacing between the components.
vgap	The number of pixels used for vertical spacing above and below the components.
alignment	The horizontal alignment for the components in the container. Possible values include LEFT, CENTER, or RIGHT.

Methods

computeUnitDimension

protected Dimension computeUnitDimension(IUIContainer target, boolean min);

Returns the maximum size of the biggest component's width and height (in pixels).

Return Value:

Returns a dimension object that contains the biggest component's width and height.

Parameter	Description
target	The container that holds the components.
min	The minimum size.

getAlignment

public int getAlignment();

Retrieves the current layout alignment.

Return Value:

Returns an integer indicating the horizontal alignment of the container's components. For a list of possible values, see setAlignment.

getMinimumSize

public Dimension getMinimumSize(IUIContainer target);

Determines the minimum dimensions (in pixels) needed to lay out the child components in the specified container.

Return Value:

Returns a Dimension object containing the minimum layout size.

Parameter	Description
target	The container of the components.

Remarks:

getMinimumSize determines the minimum size as if the components were laid in a single row. The width of the returned Dimension object is the sum of the the fixed widths of the remaining components, and the horizontal gaps between components. The fixed width is defined to be the largest of the minimum widths of the components. The Dimension object's height is the sum of the largest minimum height of all components, and the vertical gaps.

Overrides:

getMinimumSize(IUIContainer) in UILayoutManager.

See Also: getPreferredSize, layout

getPreferredSize

public Dimension getPreferredSize(IUIContainer target);

Determines the preferred dimensions (in pixels) for laying out the child components in the specified container.

Return Value:

Returns a Dimension object containing the preferred layout size.

Parameter	Description
target	The container of the components.

Remarks:

getPreferredSize determines the preferred size as if the components were laid in a single row. The width of the returned Dimension object is the sum of the the fixed widths of the remaining components and the horizontal gaps between components. The fixed width is defined to be the largest of the preferred widths of the components. The Dimension object's height is the sum of the largest preferred height of all components, and the vertical gaps.

Overrides:

getPreferredSize(IUIContainer) in UILayoutManager.

See Also: getMinimumSize, layout

isOverlapping

public boolean isOverlapping();

Determines if the container allows its children to overlap partially or completely.

Return Value:

Returns false, by default.

Overrides:

isOverlapping() in UILayoutManager.

isWidthRelative

public boolean isWidthRelative();

Determines if this layout manager uses the width of the container to lay out its children.

Return Value:

Returns true if the alignment is not LEFT; otherwise, returns false. (The default is true.) Returning false also means that the container's layout method doesn't need to be called on a vertical resizing.

Overrides:

isWidthRelative() in UILayoutManager.

layout

public void layout(IUIContainer target, Rectangle bounds);

Lays out the components in the specified container.

Return Value:

No return value.

Parameter	Description
target	The container being laid out.
bounds	The bounding rectangle in which to lay out the components.

Remarks:

The child components are laid out using the horizontal gap for spacing between each component. The width of these components is fixed to be the largest of their preferred widths. The height is the largest of the preferred heights. If necessary, the layout flows to multiple rows. (The vertical gap is used for spacing between rows.)

Each row of components is horizontally aligned within the container's available space, according to the current layout alignment (LEFT, CENTER, or RIGHT). The available space is determined from the container's size minus its horizontal and vertical gaps.

Overrides:

layout(IUIContainer,Rectangle) in UILayoutManager.

navigate

public IUIComponent navigate(IUIContainer cont, IUIComponent comp, int dir,
        boolean keyable);

Navigates from the specified component to another component in the specified direction.

Return Value:

Returns the component navigated to (if a component in the specified direction exists); otherwise, returns null.

Parameter	Description
cont	The container where the navigation is occurring.
comp	The tab component to navigate from.
dir	The navigation direction. Specify one of the following values defined in IUIAccessible: NAVDIR_LEFT NAVDIR_RIGHT NAVDIR_FIRST NAVDIR_LAST NAVDIR_NEXT NAVDIR_PREV
keyable	If true, only components that are able to receive keyboard input can be navigated to; otherwise, all components can be navigated to.

Remarks:

This method handles keyboard navigation in the container. When a component in the container has focus and a key is pressed, navigate is called to move focus to another item in the container.

The following table shows the keys that have corresponding IUIAccessible directions.

Key	IUIAccessible direction
LEFT ARROW and RIGHT ARROW	NAVDIR_LEFT and NAVDIR_RIGHT, respectively
HOME and END	NAVDIR_FIRST and NAVDIR_LAST, respectively.

Overrides:

navigate(IUIContainer,IUIComponent,int,boolean) in UILayoutManager.

setAlignment

public void setAlignment(int alignment);

Sets the layout alignment.

Return Value:

No return value.

Parameter	Description
alignment	The horizontal alignment for the container's components. Possible values include LEFT, CENTER, or RIGHT.

See Also: getAlignment

Fields

CENTER

Specifies that the layout manager will horizontally center the components in the container.

LEFT

Specifies that the layout manager will left-align the components in the container.

RIGHT

Specifies that the layout manager will right-align the components in the container.