DockLayoutPanel (GWT Javadoc)

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.DockLayoutPanel

All Implemented Interfaces:: HasAttachHandlers, HasHandlers, EventListener, AnimatedLayout, HasVisibility, HasWidgets, HasWidgets.ForIsWidget, IndexedPanel, IndexedPanel.ForIsWidget, IsWidget, ProvidesResize, RequiresResize, java.lang.Iterable<Widget>

Direct Known Subclasses:: SplitLayoutPanel

public class DockLayoutPanel
extends ComplexPanel
implements AnimatedLayout, RequiresResize, ProvidesResize

A panel that lays its child widgets out "docked" at its outer edges, and allows its last widget to take up the remaining space in its center.

This widget will only work in standards mode, which requires that the HTML page in which it is run have an explicit <!DOCTYPE> declaration.

Example

public class DockLayoutPanelExample implements EntryPoint {

  public void onModuleLoad() {
    // Attach five widgets to a DockLayoutPanel, one in each direction. Lay
    // them out in 'em' units.
    DockLayoutPanel p = new DockLayoutPanel(Unit.EM);
    p.addNorth(new HTML("north"), 2);
    p.addSouth(new HTML("south"), 2);
    p.addEast(new HTML("east"), 2);
    p.addWest(new HTML("west"), 2);
    p.add(new HTML("center"));

    // 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

DockLayoutPanel elements in UiBinder templates lay out their children in elements tagged with the cardinal directions, and center:

<g:center>
<g:north>
<g:south>
<g:west>
<g:east>

Each child can hold only widget, and there can be only one <g:center>. However, there can be any number of the directional children.

(Note that the tags of the child elements are not capitalized. This is meant to signal that they are not runtime objects, and so cannot have a ui:field attribute.)

For example:

 <g:DockLayoutPanel unit='EM'>
   <g:north size='5'>
     <g:Label>Top</g:Label>
   </g:north>
   <g:center>
     <g:Label>Body</g:Label>
   </g:center>
   <g:west size='192'>
     <g:HTML>
       <ul>
         <li>Sidebar</li>
         <li>Sidebar</li>
         <li>Sidebar</li>
       </ul>
     </g:HTML>
   </g:west>
 </g:DockLayoutPanel>

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`DockLayoutPanel.Direction` Used in `addEast(Widget, double)` et al to specify the direction in which a child widget will be added.
`protected static class`	`DockLayoutPanel.LayoutData` Layout data associated with each widget.

Nested classes/interfaces inherited from class com.google.gwt.user.client.ui.UIObject
UIObject.DebugIdImpl, UIObject.DebugIdImplEnabled

Nested classes/interfaces inherited from interface com.google.gwt.user.client.ui.IndexedPanel
IndexedPanel.ForIsWidget

Nested classes/interfaces inherited from interface com.google.gwt.user.client.ui.HasWidgets
HasWidgets.ForIsWidget

Field Summary
- Fields inherited from class com.google.gwt.user.client.ui.Widget
  eventsToSink
- Fields inherited from class com.google.gwt.user.client.ui.UIObject
  DEBUG_ID_PREFIX, MISSING_ELEMENT_ERROR, SETELEMENT_TWICE_ERROR

Constructor Summary

Constructors
Constructor and Description

DockLayoutPanel(Style.Unit unit)
Creates an empty dock panel.

Constructors
Constructor and Description
`DockLayoutPanel(Style.Unit unit)` Creates an empty dock panel.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`add(Widget widget)` Adds a widget at the center of the dock.
`void`	`addEast(IsWidget widget, double size)` Overloaded version for IsWidget.
`void`	`addEast(Widget widget, double size)` Adds a widget to the east edge of the dock.
`void`	`addLineEnd(Widget widget, double size)` Adds a widget to the end of the line.
`void`	`addLineStart(Widget widget, double size)` Adds a widget to the start of the line.
`void`	`addNorth(IsWidget widget, double size)` Overloaded version for IsWidget.
`void`	`addNorth(Widget widget, double size)` Adds a widget to the north edge of the dock.
`void`	`addSouth(IsWidget widget, double size)` Overloaded version for IsWidget.
`void`	`addSouth(Widget widget, double size)` Adds a widget to the south edge of the dock.
`void`	`addWest(IsWidget widget, double size)` Overloaded version for IsWidget.
`void`	`addWest(Widget widget, double size)` Adds a widget to the west edge of the dock.
`void`	`animate(int duration)` Layout children, animating over the specified period of time.
`void`	`animate(int duration, Layout.AnimationCallback callback)` Layout children, animating over the specified period of time.
`(package private) void`	`assertIsChild(Widget widget)`
`void`	`forceLayout()` Layout children immediately.
`protected Widget`	`getCenter()`
`protected double`	`getCenterHeight()`
`protected double`	`getCenterWidth()`
`protected DockLayoutPanel.Direction`	`getResolvedDirection(DockLayoutPanel.Direction direction)` Resolve the specified direction based on the current locale.
`protected Style.Unit`	`getUnit()`
`Element`	`getWidgetContainerElement(Widget child)` Gets the container element wrapping the given child widget.
`DockLayoutPanel.Direction`	`getWidgetDirection(Widget child)` Gets the layout direction of the given child widget.
`java.lang.Double`	`getWidgetSize(Widget child)` Gets the layout size of the given child widget.
`protected void`	`insert(Widget widget, DockLayoutPanel.Direction direction, double size, Widget before)` Adds a widget to the specified edge of the dock.
`void`	`insertEast(Widget widget, double size, Widget before)` Adds a widget to the east edge of the dock, inserting it before an existing widget.
`void`	`insertLineEnd(Widget widget, double size, Widget before)` Adds a widget to the start of the line, inserting it before an existing widget.
`void`	`insertLineStart(Widget widget, double size, Widget before)` Adds a widget to the end of the line, inserting it before an existing widget.
`void`	`insertNorth(Widget widget, double size, Widget before)` Adds a widget to the north edge of the dock, inserting it before an existing widget.
`void`	`insertSouth(Widget widget, double size, Widget before)` Adds a widget to the south edge of the dock, inserting it before an existing widget.
`void`	`insertWest(Widget widget, double size, Widget before)` Adds a widget to the west edge of the dock, inserting it before an existing widget.
`protected void`	`onAttach()` This method is called when a widget is attached to the browser's document.
`protected void`	`onDetach()` This method is called when a widget is detached from the browser's document.
`void`	`onResize()` This method must be called whenever the implementor's size has been modified.
`boolean`	`remove(Widget w)` Removes a child widget.
`void`	`setWidgetHidden(Widget widget, boolean hidden)` Sets whether or not the given widget should be hidden.
`void`	`setWidgetSize(Widget widget, double size)` Updates the size of the widget passed in as long as it is not the center widget and updates the layout of the dock.

Methods inherited from class com.google.gwt.user.client.ui.ComplexPanel
add, add, adjustIndex, checkIndexBoundsForAccess, checkIndexBoundsForInsertion, doLogicalClear, getChildren, getWidget, getWidgetCount, getWidgetIndex, getWidgetIndex, insert, insert, iterator, remove

Methods inherited from class com.google.gwt.user.client.ui.Panel
add, adopt, clear, doAttachChildren, doDetachChildren, orphan, remove

Methods inherited from class com.google.gwt.user.client.ui.Widget
addAttachHandler, addBitlessDomHandler, addDomHandler, addHandler, asWidget, asWidgetOrNull, createHandlerManager, delegateEvent, ensureHandlers, fireEvent, getHandlerCount, getHandlerManager, getLayoutData, getParent, isAttached, isOrWasAttached, onBrowserEvent, onLoad, onUnload, removeFromParent, replaceElement, setLayoutData, setParent, sinkEvents, unsinkEvents

Methods inherited from class com.google.gwt.user.client.ui.UIObject
addStyleDependentName, addStyleName, ensureDebugId, ensureDebugId, ensureDebugId, getAbsoluteLeft, getAbsoluteTop, getElement, getOffsetHeight, getOffsetWidth, getStyleElement, getStyleName, getStyleName, getStylePrimaryName, getStylePrimaryName, getTitle, isVisible, isVisible, onEnsureDebugId, removeStyleDependentName, removeStyleName, resolvePotentialElement, setElement, setElement, setHeight, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setTitle, setVisible, setVisible, setWidth, sinkBitlessEvent, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable
forEach, spliterator

- Constructor Detail
  - DockLayoutPanel
```
public DockLayoutPanel(Style.Unit unit)
```
    Creates an empty dock panel.
    
    Parameters:
    
    unit - the unit to be used for layout
- Method Detail
  - add
```
public void add(Widget widget)
```
    Adds a widget at the center of the dock. No further widgets may be added after this one.
    
    Specified by:
    
    add in interface HasWidgets
    
    Overrides:
    
    add in class Panel
    
    Parameters:
    
    widget - the widget to be added
    
    See Also:
    
    HasWidgets.add(Widget)
  - addEast
```
public void addEast(Widget widget,
                    double size)
```
    Adds a widget to the east edge of the dock.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
  - addEast
```
public void addEast(IsWidget widget,
                    double size)
```
    Overloaded version for IsWidget.
    
    See Also:
    
    addEast(Widget,double)
  - addLineEnd
```
public void addLineEnd(Widget widget,
                       double size)
```
    Adds a widget to the end of the line. In LTR mode, the widget is added to the east. In RTL mode, the widget is added to the west.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
  - addLineStart
```
public void addLineStart(Widget widget,
                         double size)
```
    Adds a widget to the start of the line. In LTR mode, the widget is added to the west. In RTL mode, the widget is added to the east.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
  - addNorth
```
public void addNorth(Widget widget,
                     double size)
```
    Adds a widget to the north edge of the dock.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
  - addNorth
```
public void addNorth(IsWidget widget,
                     double size)
```
    Overloaded version for IsWidget.
    
    See Also:
    
    addNorth(Widget,double)
  - addSouth
```
public void addSouth(Widget widget,
                     double size)
```
    Adds a widget to the south edge of the dock.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
  - addSouth
```
public void addSouth(IsWidget widget,
                     double size)
```
    Overloaded version for IsWidget.
    
    See Also:
    
    addSouth(Widget,double)
  - addWest
```
public void addWest(Widget widget,
                    double size)
```
    Adds a widget to the west edge of the dock.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
  - addWest
```
public void addWest(IsWidget widget,
                    double size)
```
    Overloaded version for IsWidget.
    
    See Also:
    
    addWest(Widget,double)
  - 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
  - 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:
    
    AnimatedLayout.animate(int), AnimatedLayout.animate(int, Layout.AnimationCallback)
  - getWidgetContainerElement
```
public Element getWidgetContainerElement(Widget child)
```
    Gets the container element wrapping the given child widget.
    
    Parameters:
    
    child -
    
    Returns:
    
    the widget's container element
  - getWidgetDirection
```
public DockLayoutPanel.Direction getWidgetDirection(Widget child)
```
    Gets the layout direction of the given child widget.
    
    Parameters:
    
    child - the widget to be queried
    
    Returns:
    
    the widget's layout direction, or null if it is not a child of this panel
    
    Throws:
    
    java.lang.AssertionError - if the widget is not a child and assertions are enabled
  - getWidgetSize
```
public java.lang.Double getWidgetSize(Widget child)
```
    Gets the layout size of the given child widget.
    
    Parameters:
    
    child - the widget to be queried
    
    Returns:
    
    the widget's layout size, or null if it is not a child of this panel
    
    Throws:
    
    java.lang.AssertionError - if the widget is not a child and assertions are enabled
  - insertEast
```
public void insertEast(Widget widget,
                       double size,
                       Widget before)
```
    Adds a widget to the east edge of the dock, inserting it before an existing widget.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
    
    before - the widget before which to insert the new child, or null to append
  - insertLineEnd
```
public void insertLineEnd(Widget widget,
                          double size,
                          Widget before)
```
    Adds a widget to the start of the line, inserting it before an existing widget. In LTR mode, the widget is added to the east. In RTL mode, the widget is added to the west.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
    
    before - the widget before which to insert the new child, or null to append
  - insertLineStart
```
public void insertLineStart(Widget widget,
                            double size,
                            Widget before)
```
    Adds a widget to the end of the line, inserting it before an existing widget. In LTR mode, the widget is added to the west. In RTL mode, the widget is added to the east.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
    
    before - the widget before which to insert the new child, or null to append
  - insertNorth
```
public void insertNorth(Widget widget,
                        double size,
                        Widget before)
```
    Adds a widget to the north edge of the dock, inserting it before an existing widget.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
    
    before - the widget before which to insert the new child, or null to append
  - insertSouth
```
public void insertSouth(Widget widget,
                        double size,
                        Widget before)
```
    Adds a widget to the south edge of the dock, inserting it before an existing widget.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
    
    before - the widget before which to insert the new child, or null to append
  - insertWest
```
public void insertWest(Widget widget,
                       double size,
                       Widget before)
```
    Adds a widget to the west edge of the dock, inserting it before an existing widget.
    
    Parameters:
    
    widget - the widget to be added
    
    size - the child widget's size
    
    before - the widget before which to insert the new child, or null to append
  - 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
  - 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
  - setWidgetHidden
```
public void setWidgetHidden(Widget widget,
                            boolean hidden)
```
    Sets whether or not the given widget should be hidden.
    
    Parameters:
    
    widget - the widget to hide or display
    
    hidden - true to hide the widget, false to display it
  - setWidgetSize
```
public void setWidgetSize(Widget widget,
                          double size)
```
    Updates the size of the widget passed in as long as it is not the center widget and updates the layout of the dock.
    
    Parameters:
    
    widget - the widget that needs to update its size
    
    size - the size to update the widget to
  - getCenter
```
protected Widget getCenter()
```
  - getCenterHeight
```
protected double getCenterHeight()
```
  - getCenterWidth
```
protected double getCenterWidth()
```
  - getResolvedDirection
```
protected DockLayoutPanel.Direction getResolvedDirection(DockLayoutPanel.Direction direction)
```
    Resolve the specified direction based on the current locale. If the direction is DockLayoutPanel.Direction.LINE_START or DockLayoutPanel.Direction.LINE_END, the return value will be one of DockLayoutPanel.Direction.EAST or DockLayoutPanel.Direction.WEST depending on the RTL mode of the locale. For all other directions, the specified value is returned.
    
    Parameters:
    
    direction - the specified direction
    
    Returns:
    
    the locale
  - getUnit
```
protected Style.Unit getUnit()
```
  - insert
```
protected void insert(Widget widget,
                      DockLayoutPanel.Direction direction,
                      double size,
                      Widget before)
```
    Adds a widget to the specified edge of the dock. If the widget is already a child of this panel, this method behaves as though remove(Widget) had already been called.
    
    Parameters:
    
    widget - the widget to be added
    
    direction - the widget's direction in the dock
    
    before - the widget before which to insert the new child, or null to append
  - onAttach
```
protected void onAttach()
```
    Description copied from class: Widget
    
    This method is called when a widget is attached to the browser's document. To receive notification after a Widget has been added to the document, override the Widget.onLoad() method or use Widget.addAttachHandler(com.google.gwt.event.logical.shared.AttachEvent.Handler).
    
    It is strongly recommended that you override Widget.onLoad() or Widget.doAttachChildren() instead of this method to avoid inconsistencies between logical and physical attachment states.
    
    Subclasses that override this method must call super.onAttach() to ensure that the Widget has been attached to its underlying Element.
    
    Overrides:
    
    onAttach in class Widget
    
    See Also:
    
    Widget.onLoad(), Widget.doAttachChildren()
  - onDetach
```
protected void onDetach()
```
    Description copied from class: Widget
    
    This method is called when a widget is detached from the browser's document. To receive notification before a Widget is removed from the document, override the Widget.onUnload() method or use Widget.addAttachHandler(com.google.gwt.event.logical.shared.AttachEvent.Handler).
    
    It is strongly recommended that you override Widget.onUnload() or Widget.doDetachChildren() instead of this method to avoid inconsistencies between logical and physical attachment states.
    
    Subclasses that override this method must call super.onDetach() to ensure that the Widget has been detached from the underlying Element. Failure to do so will result in application memory leaks due to circular references between DOM Elements and JavaScript objects.
    
    Overrides:
    
    onDetach in class Widget
    
    See Also:
    
    Widget.onUnload(), Widget.doDetachChildren()
  - assertIsChild
```
void assertIsChild(Widget widget)
```

Class DockLayoutPanel

Example

Use in UiBinder Templates

Nested Class Summary

Nested classes/interfaces inherited from class com.google.gwt.user.client.ui.UIObject

Nested classes/interfaces inherited from interface com.google.gwt.user.client.ui.IndexedPanel

Nested classes/interfaces inherited from interface com.google.gwt.user.client.ui.HasWidgets

Field Summary

Fields inherited from class com.google.gwt.user.client.ui.Widget

Fields inherited from class com.google.gwt.user.client.ui.UIObject

Constructor Summary

Method Summary

Methods inherited from class com.google.gwt.user.client.ui.ComplexPanel

Methods inherited from class com.google.gwt.user.client.ui.Panel

Methods inherited from class com.google.gwt.user.client.ui.Widget

Methods inherited from class com.google.gwt.user.client.ui.UIObject

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Iterable

Constructor Detail

DockLayoutPanel

Method Detail

add

addEast

addEast

addLineEnd

addLineStart

addNorth

addNorth

addSouth

addSouth

addWest

addWest

animate

animate

forceLayout

getWidgetContainerElement

getWidgetDirection

getWidgetSize

insertEast

insertLineEnd

insertLineStart

insertNorth

insertSouth

insertWest

onResize

remove

setWidgetHidden

setWidgetSize

getCenter

getCenterHeight

getCenterWidth

getResolvedDirection

getUnit

insert

onAttach

onDetach

assertIsChild