com.google.gwt.user.client.ui
Class HorizontalPanel

java.lang.Object
  com.google.gwt.user.client.ui.UIObject
      com.google.gwt.user.client.ui.Widget
          com.google.gwt.user.client.ui.Panel
              com.google.gwt.user.client.ui.ComplexPanel
                  com.google.gwt.user.client.ui.CellPanel
                      com.google.gwt.user.client.ui.HorizontalPanel

All Implemented Interfaces:

HasHandlers, EventListener, HasAlignment, HasHorizontalAlignment, HasVerticalAlignment, HasWidgets, IndexedPanel, InsertPanel, java.lang.Iterable<Widget>

public class HorizontalPanel
extends CellPanel
implements HasAlignment, InsertPanel

A panel that lays all of its widgets out in a single horizontal column.

HorizontalPanel

public HorizontalPanel()

Creates an empty horizontal panel.

add

public void add(Widget w)

Description copied from class: Panel

Adds a child widget.

How to Override this Method

There are several important things that must take place in the correct order to properly add or insert a Widget to a Panel. Not all of these steps will be relevant to every Panel, but all of the steps must be considered.

1. Validate: Perform any sanity checks to ensure the Panel can accept a new Widget. Examples: checking for a valid index on insertion; checking that the Panel is not full if there is a max capacity.
2. Adjust for Reinsertion: Some Panels need to handle the case where the Widget is already a child of this Panel. Example: when performing a reinsert, the index might need to be adjusted to account for the Widget's removal. See ComplexPanel.adjustIndex(Widget, int).
3. Detach Child: Remove the Widget from its existing parent, if any. Most Panels will simply call Widget.removeFromParent() on the Widget.
4. Logical Attach: Any state variables of the Panel should be updated to reflect the addition of the new Widget. Example: the Widget is added to the Panel's WidgetCollection at the appropriate index.
5. Physical Attach: The Widget's Element must be physically attached to the Panel's Element, either directly or indirectly.
6. Adopt: Call Panel.adopt(Widget) to finalize the add as the very last step.

Specified by:

add in interface HasWidgets

Specified by:

add in interface InsertPanel

Overrides:

add in class Panel

Parameters:

w - the widget to be added

See Also:

HasWidgets.add(Widget)

getHorizontalAlignment

public HasHorizontalAlignment.HorizontalAlignmentConstant getHorizontalAlignment()

Description copied from interface: HasHorizontalAlignment

Gets the horizontal alignment.

Specified by:

getHorizontalAlignment in interface HasHorizontalAlignment

Returns:

the current horizontal alignment.

getVerticalAlignment

public HasVerticalAlignment.VerticalAlignmentConstant getVerticalAlignment()

Description copied from interface: HasVerticalAlignment

Gets the vertical alignment.

Specified by:

getVerticalAlignment in interface HasVerticalAlignment

Returns:

the current vertical alignment.

insert

public void insert(Widget w,
                   int beforeIndex)

Description copied from interface: InsertPanel

Inserts a child widget before the specified index. If the widget is already a child of this panel, it will be moved to the specified index.

Specified by:

insert in interface InsertPanel

Parameters:

w - the child widget to be inserted

beforeIndex - the index before which it will be inserted

remove

public boolean remove(Widget w)

Description copied from class: Panel

Removes a child widget.

How to Override this Method

There are several important things that must take place in the correct order to properly remove a Widget from a Panel. Not all of these steps will be relevant to every Panel, but all of the steps must be considered.

1. Validate: Make sure this Panel is actually the parent of the child Widget; return false if it is not.
2. Orphan: Call Panel.orphan(Widget) first while the child Widget is still attached.
3. Physical Detach: Adjust the DOM to account for the removal of the child Widget. The Widget's Element must be physically removed from the DOM.
4. Logical Detach: Update the Panel's state variables to reflect the removal of the child Widget. Example: the Widget is removed from the Panel's WidgetCollection.

Specified by:

remove in interface HasWidgets

Overrides:

remove in class ComplexPanel

Parameters:

w - the widget to be removed

Returns:

true if the child was present

setHorizontalAlignment

public void setHorizontalAlignment(HasHorizontalAlignment.HorizontalAlignmentConstant align)

Sets the default horizontal alignment to be used for widgets added to this panel. It only applies to widgets added after this property is set.

Specified by:

setHorizontalAlignment in interface HasHorizontalAlignment

Parameters:

align - the horizontal alignment ( HasHorizontalAlignment.ALIGN_LEFT, HasHorizontalAlignment.ALIGN_CENTER, HasHorizontalAlignment.ALIGN_RIGHT), or HasHorizontalAlignment.ALIGN_DEFAULT).

See Also:

HasHorizontalAlignment.setHorizontalAlignment(HasHorizontalAlignment.HorizontalAlignmentConstant)

setVerticalAlignment

public void setVerticalAlignment(HasVerticalAlignment.VerticalAlignmentConstant align)

Sets the default vertical alignment to be used for widgets added to this panel. It only applies to widgets added after this property is set.

Specified by:

setVerticalAlignment in interface HasVerticalAlignment

Parameters:

align - the vertical alignment ( HasVerticalAlignment.ALIGN_TOP, HasVerticalAlignment.ALIGN_MIDDLE, or HasVerticalAlignment.ALIGN_BOTTOM).

See Also:

HasVerticalAlignment.setVerticalAlignment(HasVerticalAlignment.VerticalAlignmentConstant)

onEnsureDebugId

protected void onEnsureDebugId(java.lang.String baseID)

Affected Elements:

• -# = the cell at the given index.

Overrides:

onEnsureDebugId in class UIObject

Parameters:

baseID - the base ID used by the main element

See Also:

UIObject.onEnsureDebugId(String)