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

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.StackPanel

All Implemented Interfaces:

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

Direct Known Subclasses:

DecoratedStackPanel

public class StackPanel
extends ComplexPanel
implements InsertPanel

A panel that stacks its children vertically, displaying only one at a time, with a header for each child which the user can click to display.

This widget will only work in quirks mode. If your application is in Standards Mode, use StackLayoutPanel instead.

CSS Style Rules

• .gwt-StackPanel { the panel itself }
• .gwt-StackPanel .gwt-StackPanelItem { unselected items }
• .gwt-StackPanel .gwt-StackPanelItem-selected { selected items }
• .gwt-StackPanel .gwt-StackPanelContent { the wrapper around the contents of the item }

Example

public class StackPanelExample implements EntryPoint {

  public void onModuleLoad() {
    // Create a stack panel containing three labels.
    StackPanel panel = new StackPanel();
    panel.add(new Label("Foo"), "foo");
    panel.add(new Label("Bar"), "bar");
    panel.add(new Label("Baz"), "baz");

    // Add it to the root panel.
    RootPanel.get().add(panel);
  }
}

See Also:

StackLayoutPanel

StackPanel

public StackPanel()

Creates an empty stack 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)

add

public void add(Widget w,
                java.lang.String stackText)

Adds a new child with the given widget and header.

Parameters:

w - the widget to be added

stackText - the header text associated with this widget

add

public void add(Widget w,
                java.lang.String stackText,
                boolean asHTML)

Adds a new child with the given widget and header, optionally interpreting the header as HTML.

Parameters:

w - the widget to be added

stackText - the header text associated with this widget

asHTML - true to treat the specified text as HTML

getSelectedIndex

public int getSelectedIndex()

Gets the currently selected child index.

Returns:

selected child

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

onBrowserEvent

public void onBrowserEvent(Event event)

Description copied from interface: EventListener

Fired whenever a browser event is received.

Specified by:

onBrowserEvent in interface EventListener

Overrides:

onBrowserEvent in class Widget

Parameters:

event - the event received

remove

public boolean remove(int index)

Description copied from interface: IndexedPanel

Removes the widget at the specified index.

Specified by:

remove in interface IndexedPanel

Overrides:

remove in class ComplexPanel

Parameters:

index - the index of the widget to be removed

Returns:

false if the widget is not present

remove

public boolean remove(Widget child)

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:

child - the widget to be removed

Returns:

true if the child was present

setStackText

public void setStackText(int index,
                         java.lang.String text)

Sets the text associated with a child by its index.

Parameters:

index - the index of the child whose text is to be set

text - the text to be associated with it

setStackText

public void setStackText(int index,
                         java.lang.String text,
                         boolean asHTML)

Sets the text associated with a child by its index.

Parameters:

index - the index of the child whose text is to be set

text - the text to be associated with it

asHTML - true to treat the specified text as HTML

showStack

public void showStack(int index)

Shows the widget at the specified child index.

Parameters:

index - the index of the child to be shown

onEnsureDebugId

protected void onEnsureDebugId(java.lang.String baseID)

Affected Elements:

• -text# = The element around the header at the specified index.
• -text-wrapper# = The element around the header at the specified index.
• -content# = The element around the body at the specified index.

Overrides:

onEnsureDebugId in class UIObject

Parameters:

baseID - the base ID used by the main element

See Also:

UIObject.onEnsureDebugId(String)