Package com.google.gwt.user.client.ui

Class StackLayoutPanel

java.lang.Object
com.google.gwt.user.client.ui.UIObject
com.google.gwt.user.client.ui.Widget
com.google.gwt.user.client.ui.Composite
com.google.gwt.user.client.ui.ResizeComposite
com.google.gwt.user.client.ui.StackLayoutPanel
All Implemented Interfaces:
HasAttachHandlers, HasBeforeSelectionHandlers<Integer>, HasSelectionHandlers<Integer>, HasHandlers, EventListener, AnimatedLayout, HasVisibility, HasWidgets, IndexedPanel, IndexedPanel.ForIsWidget, IsRenderable, IsWidget, ProvidesResize, RequiresResize, Iterable<Widget>
public class StackLayoutPanel extends ResizeComposite implements HasWidgets, ProvidesResize, IndexedPanel.ForIsWidget, AnimatedLayout, HasBeforeSelectionHandlers<Integer>, HasSelectionHandlers<Integer>
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 standards mode, which requires that the HTML page in which it is run have an explicit <!DOCTYPE> declaration.

CSS Style Rules

.gwt-StackLayoutPanel
the panel itself
.gwt-StackLayoutPanel .gwt-StackLayoutPanelHeader
applied to each header widget
.gwt-StackLayoutPanel .gwt-StackLayoutPanelHeader-hovering
applied to each header widget on mouse hover
.gwt-StackLayoutPanel .gwt-StackLayoutPanelContent
applied to each child widget

Example

public class StackLayoutPanelExample implements EntryPoint {

  public void onModuleLoad() {
    // Create a three-item stack, with headers sized in EMs. 
    StackLayoutPanel p = new StackLayoutPanel(Unit.EM);
    p.add(new HTML("this"), new HTML("[this]"), 4);
    p.add(new HTML("that"), new HTML("[that]"), 4);
    p.add(new HTML("the other"), new HTML("[the other]"), 4);

    // Attach the LayoutPanel to the RootLayoutPanel. The latter will listen for
    // resize events on the window to ensure that its children are informed of
    // possible size changes.
    RootLayoutPanel rp = RootLayoutPanel.get();
    rp.add(p);
  }
}

Use in UiBinder Templates

A StackLayoutPanel element in a UiBinder template may have a unit attribute with a Style.Unit value (it defaults to PX).

The children of a StackLayoutPanel element are laid out in <g:stack> elements. Each stack can have one widget child and one of two types of header elements. A <g:header> element can hold html, or a <g:customHeader> element can hold a widget. (Note that the tags of the header elements are not capitalized. This is meant to signal that the head is not a runtime object, and so cannot have a ui:field attribute.)

For example: 

 <g:StackLayoutPanel unit='PX'>
  <g:stack>
    <g:header size='3'><b>HTML</b> header</g:header>
    <g:Label>able</g:Label>
  </g:stack>
  <g:stack>
    <g:customHeader size='3'>
      <g:Label>Custom header</g:Label>
    </g:customHeader>
    <g:Label>baker</g:Label>
  </g:stack>
 </g:StackLayoutPanel>

  • Constructor Details

    • StackLayoutPanel

      public StackLayoutPanel(Style.Unit unit)
      Creates an empty stack panel.
      Parameters:
      unit - the unit to be used for layout

  • Method Details

    • add

      public void add(Widget w)
      Description copied from interface: HasWidgets
      Adds a child widget.
      Specified by:
      add in interface HasWidgets
      Parameters:
      w - the widget to be added

    • add

      public void add(Widget widget, SafeHtml header, double headerSize)
      Adds a child widget to this stack, along with a widget representing the stack header.
      Parameters:
      widget - the child widget to be added
      header - the html to be shown on its header
      headerSize - the size of the header widget

    • add

      public void add(Widget widget, String header, boolean asHtml, double headerSize)
      Adds a child widget to this stack, along with a widget representing the stack header.
      Parameters:
      widget - the child widget to be added
      header - the text to be shown on its header
      asHtml - true to treat the specified text as HTML
      headerSize - the size of the header widget

    • add

      public void add(IsWidget widget, String header, boolean asHtml, double headerSize)
      Overloaded version for IsWidget.
      See Also:

    • add

      public void add(Widget widget, String header, double headerSize)
      Adds a child widget to this stack, along with a widget representing the stack header.
      Parameters:
      widget - the child widget to be added
      header - the text to be shown on its header
      headerSize - the size of the header widget

    • add

      public void add(Widget widget, Widget header, double headerSize)
      Adds a child widget to this stack, along with a widget representing the stack header.
      Parameters:
      widget - the child widget to be added
      header - the header widget
      headerSize - the size of the header widget

    • add

      public void add(IsWidget widget, IsWidget header, double headerSize)
      Overloaded version for IsWidget.
      See Also:

    • addBeforeSelectionHandler

      public HandlerRegistration addBeforeSelectionHandler(BeforeSelectionHandler<Integer> handler)
      Description copied from interface: HasBeforeSelectionHandlers
      Adds a BeforeSelectionEvent handler.
      Specified by:
      addBeforeSelectionHandler in interface HasBeforeSelectionHandlers<Integer>
      Parameters:
      handler - the handler
      Returns:
      the registration for the event

    • addSelectionHandler

      public HandlerRegistration addSelectionHandler(SelectionHandler<Integer> handler)
      Description copied from interface: HasSelectionHandlers
      Adds a SelectionEvent handler.
      Specified by:
      addSelectionHandler in interface HasSelectionHandlers<Integer>
      Parameters:
      handler - the handler
      Returns:
      the registration for the event

    • animate

      public void animate(int duration)
      Description copied from interface: AnimatedLayout
      Layout children, animating over the specified period of time.
      Specified by:
      animate in interface AnimatedLayout
      Parameters:
      duration - the animation duration, in milliseconds

    • animate

      public void animate(int duration, Layout.AnimationCallback callback)
      Description copied from interface: AnimatedLayout
      Layout children, animating over the specified period of time.

      This method provides a callback that will be informed of animation updates. This can be used to create more complex animation effects.

      Specified by:
      animate in interface AnimatedLayout
      Parameters:
      duration - the animation duration, in milliseconds
      callback - the animation callback

    • clear

      public void clear()
      Description copied from interface: HasWidgets
      Removes all child widgets.
      Specified by:
      clear in interface HasWidgets

    • forceLayout

      public void forceLayout()
      Description copied from interface: AnimatedLayout
      Layout children immediately.

      This is not normally necessary, unless you want to update child widgets' positions explicitly to create a starting point for a subsequent call to AnimatedLayout.animate(int).

      Specified by:
      forceLayout in interface AnimatedLayout
      See Also:

    • getAnimationDuration

      public int getAnimationDuration()
      Get the duration of the animated transition between children.
      Returns:
      the duration in milliseconds

    • getHeaderWidget

      public Widget getHeaderWidget(int index)
      Gets the widget in the stack header at the given index.
      Parameters:
      index - the index of the stack header to be retrieved
      Returns:
      the header widget

    • getHeaderWidget

      public Widget getHeaderWidget(Widget child)
      Gets the widget in the stack header associated with the given child widget.
      Parameters:
      child - the child whose stack header is to be retrieved
      Returns:
      the header widget

    • getVisibleIndex

      public int getVisibleIndex()
      Gets the currently-selected index.
      Returns:
      the selected index, or -1 if none is selected

    • getVisibleWidget

      public Widget getVisibleWidget()
      Gets the currently-selected widget.
      Returns:
      the selected widget, or null if none exist

    • getWidget

      public Widget getWidget(int index)
      Description copied from interface: IndexedPanel
      Gets the child widget at the specified index.
      Specified by:
      getWidget in interface IndexedPanel
      Parameters:
      index - the child widget's index
      Returns:
      the child widget

    • getWidgetCount

      public int getWidgetCount()
      Description copied from interface: IndexedPanel
      Gets the number of child widgets in this panel.
      Specified by:
      getWidgetCount in interface IndexedPanel
      Returns:
      the number of children

    • getWidgetIndex

      public int getWidgetIndex(IsWidget child)
      Specified by:
      getWidgetIndex in interface IndexedPanel.ForIsWidget

    • getWidgetIndex

      public int getWidgetIndex(Widget child)
      Description copied from interface: IndexedPanel
      Gets the index of the specified child widget.
      Specified by:
      getWidgetIndex in interface IndexedPanel
      Parameters:
      child - the widget to be found
      Returns:
      the widget's index, or -1 if it is not a child of this panel

    • insert

      public void insert(Widget child, SafeHtml html, double headerSize, int beforeIndex)
      Inserts a widget into the panel. If the Widget is already attached, it will be moved to the requested index.
      Parameters:
      child - the widget to be added
      html - the safe html to be shown on its header
      headerSize - the size of the header widget
      beforeIndex - the index before which it will be inserted

    • insert

      public void insert(Widget child, String text, boolean asHtml, double headerSize, int beforeIndex)
      Inserts a widget into the panel. If the Widget is already attached, it will be moved to the requested index.
      Parameters:
      child - the widget to be added
      text - the text to be shown on its header
      asHtml - true to treat the specified text as HTML
      headerSize - the size of the header widget
      beforeIndex - the index before which it will be inserted

    • insert

      public void insert(Widget child, String text, double headerSize, int beforeIndex)
      Inserts a widget into the panel. If the Widget is already attached, it will be moved to the requested index.
      Parameters:
      child - the widget to be added
      text - the text to be shown on its header
      headerSize - the size of the header widget
      beforeIndex - the index before which it will be inserted

    • insert

      public void insert(Widget child, Widget header, double headerSize, int beforeIndex)
      Inserts a widget into the panel. If the Widget is already attached, it will be moved to the requested index.
      Parameters:
      child - the widget to be added
      header - the widget to be placed in the associated header
      headerSize - the size of the header widget
      beforeIndex - the index before which it will be inserted

    • iterator

      public Iterator<Widget> iterator()
      Description copied from interface: HasWidgets
      Gets an iterator for the contained widgets. This iterator is required to implement Iterator.remove().
      Specified by:
      iterator in interface HasWidgets
      Specified by:
      iterator in interface Iterable<Widget>

    • onResize

      public void onResize()
      Description copied from interface: RequiresResize
      This method must be called whenever the implementor's size has been modified.
      Specified by:
      onResize in interface RequiresResize
      Overrides:
      onResize in class ResizeComposite

    • remove

      public boolean remove(int index)
      Description copied from interface: IndexedPanel
      Removes the widget at the specified index.
      Specified by:
      remove in interface IndexedPanel
      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 interface: HasWidgets
      Removes a child widget.
      Specified by:
      remove in interface HasWidgets
      Parameters:
      child - the widget to be removed
      Returns:
      true if the widget was present

    • setAnimationDuration

      public void setAnimationDuration(int duration)
      Set the duration of the animated transition between children.
      Parameters:
      duration - the duration in milliseconds.

    • setHeaderHTML

      public void setHeaderHTML(int index, String html)
      Sets a stack header's HTML contents. Use care when setting an object's HTML; it is an easy way to expose script-based security problems. Consider using setHeaderHTML(int, SafeHtml) or setHeaderText(int, String) whenever possible.
      Parameters:
      index - the index of the header whose HTML is to be set
      html - the header's new HTML contents

    • setHeaderHTML

      public void setHeaderHTML(int index, SafeHtml html)
      Sets a stack header's HTML contents.
      Parameters:
      index - the index of the header whose HTML is to be set
      html - the header's new HTML contents

    • setHeaderText

      public void setHeaderText(int index, String text)
      Sets a stack header's text contents.
      Parameters:
      index - the index of the header whose text is to be set
      text - the object's new text

    • showWidget

      public void showWidget(int index)
      Shows the widget at the specified index and fires events.
      Parameters:
      index - the index of the child widget to be shown.

    • showWidget

      public void showWidget(int index, boolean fireEvents)
      Shows the widget at the specified index.
      Parameters:
      index - the index of the child widget to be shown.
      fireEvents - true to fire events, false not to

    • showWidget

      public void showWidget(Widget child)
      Shows the specified widget and fires events.
      Parameters:
      child - the child widget to be shown.

    • showWidget

      public void showWidget(Widget child, boolean fireEvents)
      Shows the specified widget.
      Parameters:
      child - the child widget to be shown.
      fireEvents - true to fire events, false not to

    • onLoad

      protected void onLoad()
      Description copied from class: Widget
      This method is called immediately after a widget becomes attached to the browser's document.
      Overrides:
      onLoad in class Widget