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

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.SimplePanel
                  com.google.gwt.user.client.ui.PopupPanel

All Implemented Interfaces:

EventListener, EventPreview, HasWidgets, SourcesPopupEvents

Direct Known Subclasses:

DialogBox

public class PopupPanel
extends SimplePanel
implements SourcesPopupEvents, EventPreview

A panel that can "pop up" over other widgets. It overlays the browser's client area (and any previously-created popups).

The width and height of the PopupPanel cannot be explicitly set; they are determined by the PopupPanel's widget. Calls to setWidth(String) and setHeight(String) will call these methods on the PopupPanel's widget.

Example

public class PopupPanelExample implements EntryPoint {

  private static class MyPopup extends PopupPanel {

    public MyPopup() {
      // PopupPanel's constructor takes 'auto-hide' as its boolean parameter.
      // If this is set, the panel closes itself automatically when the user
      // clicks outside of it.
      super(true);

      // PopupPanel is a SimplePanel, so you have to set it's widget property to
      // whatever you want its contents to be.
      setWidget(new Label("Click outside of this popup to close it"));
    }
  }

  public void onModuleLoad() {
    Button b1 = new Button("Click me to show popup");
    b1.addClickListener(new ClickListener() {
      public void onClick(Widget sender) {
        // Instantiate the popup and show it.
        new MyPopup().show();
      }
    });

    RootPanel.get().add(b1);

    Button b2 = new Button("Click me to show popup partway across the screen");

    b2.addClickListener(new ClickListener() {
      public void onClick(Widget sender) {
        // Create the new popup.
        final MyPopup popup = new MyPopup();
        // Position the popup 1/3rd of the way down and across the screen, and
        // show the popup. Since the position calculation is based on the
        // offsetWidth and offsetHeight of the popup, you have to use the
        // setPopupPositionAndShow(callback) method. The alternative would
        // be to call show(), calculate the left and top positions, and
        // call setPopupPosition(left, top). This would have the ugly side
        // effect of the popup jumping from its original position to its
        // new position.
        popup.setPopupPositionAndShow(new PopupPanel.PositionCallback() {
          public void setPosition(int offsetWidth, int offsetHeight) {
            int left = (Window.getClientWidth() - offsetWidth) / 3;
            int top = (Window.getClientHeight() - offsetHeight) / 3;
            popup.setPopupPosition(left, top);
          }
        });
      }
    });

    RootPanel.get().add(b2);
  }
}

Nested Class Summary

static interface

PopupPanel.PositionCallback A callback that is used to set the position of a PopupPanel right before it is shown.

Constructor Summary

PopupPanel()
Creates an empty popup panel.

PopupPanel(boolean autoHide)
Creates an empty popup panel, specifying its "auto-hide" property.

PopupPanel(boolean autoHide, boolean modal)
Creates an empty popup panel, specifying its "auto-hide" property.

Method Summary

void	addPopupListener(PopupListener listener) Adds a listener interface to receive popup events.
void	center() Centers the popup in the browser window and shows it.
protected Element	getContainerElement() Override this method to specify that an element other than the root element be the container for the panel's child widget.
int	getOffsetHeight() Gets the panel's offset height in pixels.
int	getOffsetWidth() Gets the panel's offset width in pixels.
int	getPopupLeft() Gets the popup's left position relative to the browser's client area.
int	getPopupTop() Gets the popup's top position relative to the browser's client area.
protected Element	getStyleElement() Template method that returns the element to which style names will be applied.
java.lang.String	getTitle() Gets the title associated with this object.
void	hide() Hides the popup.
protected void	onDetach() This method is called when a widget is detached from the browser's document.
boolean	onEventPreview(Event event) Called when a browser event occurs and this event preview is on top of the preview stack.
boolean	onKeyDownPreview(char key, int modifiers) Popups get an opportunity to preview keyboard events before they are passed to a widget contained by the Popup.
boolean	onKeyPressPreview(char key, int modifiers) Popups get an opportunity to preview keyboard events before they are passed to a widget contained by the Popup.
boolean	onKeyUpPreview(char key, int modifiers) Popups get an opportunity to preview keyboard events before they are passed to a widget contained by the Popup.
void	removePopupListener(PopupListener listener) Removes a previously added popup listener.
void	setHeight(java.lang.String height) Sets the height of the panel's child widget.
void	setPopupPosition(int left, int top) Sets the popup's position relative to the browser's client area.
void	setPopupPositionAndShow(PopupPanel.PositionCallback callback) Sets the popup's position using a PopupPanel.PositionCallback, and shows the popup.
void	setTitle(java.lang.String title) Sets the title associated with this object.
void	setVisible(boolean visible) Sets whether this object is visible.
void	setWidget(Widget w) Sets this panel's widget.
void	setWidth(java.lang.String width) Sets the width of the panel's child widget.
void	show() Shows the popup.

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

add, getWidget, iterator, remove

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

adopt, adopt, clear, disown, doAttachChildren, doDetachChildren, onLoad, onUnload, orphan

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

getParent, isAttached, onAttach, onBrowserEvent, removeFromParent, setElement

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

addStyleDependentName, addStyleName, getAbsoluteLeft, getAbsoluteTop, getElement, getStyleName, getStyleName, getStylePrimaryName, getStylePrimaryName, isVisible, isVisible, removeStyleDependentName, removeStyleName, setPixelSize, setSize, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setVisible, sinkEvents, toString, unsinkEvents

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

PopupPanel

public PopupPanel()

Creates an empty popup panel. A child widget must be added to it before it is shown.

PopupPanel

public PopupPanel(boolean autoHide)

Creates an empty popup panel, specifying its "auto-hide" property.

Parameters:

autoHide - true if the popup should be automatically hidden when the user clicks outside of it

PopupPanel

public PopupPanel(boolean autoHide,
                  boolean modal)

Creates an empty popup panel, specifying its "auto-hide" property.

Parameters:

autoHide - true if the popup should be automatically hidden when the user clicks outside of it

modal - true if keyboard or mouse events that do not target the PopupPanel or its children should be ignored

Method Detail

addPopupListener

public void addPopupListener(PopupListener listener)

Description copied from interface: SourcesPopupEvents

Adds a listener interface to receive popup events.

Specified by:

addPopupListener in interface SourcesPopupEvents

Parameters:

listener - the listener interface to add.

center

public void center()

Centers the popup in the browser window and shows it. If the popup was already showing, then the popup is centered.

getOffsetHeight

public int getOffsetHeight()

Gets the panel's offset height in pixels. Calls to setHeight(String) before the panel's child widget is set will not influence the offset height.

Overrides:

getOffsetHeight in class UIObject

Returns:

the object's offset height

getOffsetWidth

public int getOffsetWidth()

Gets the panel's offset width in pixels. Calls to setWidth(String) before the panel's child widget is set will not influence the offset width.

Overrides:

getOffsetWidth in class UIObject

Returns:

the object's offset width

getPopupLeft

public int getPopupLeft()

Gets the popup's left position relative to the browser's client area.

Returns:

the popup's left position

getPopupTop

public int getPopupTop()

Gets the popup's top position relative to the browser's client area.

Returns:

the popup's top position

getTitle

public java.lang.String getTitle()

Description copied from class: UIObject

Gets the title associated with this object. The title is the 'tool-tip' displayed to users when they hover over the object.

Overrides:

getTitle in class UIObject

Returns:

the object's title

hide

public void hide()

Hides the popup. This has no effect if it is not currently visible.

onEventPreview

public boolean onEventPreview(Event event)

Description copied from interface: EventPreview

Called when a browser event occurs and this event preview is on top of the preview stack.

Specified by:

onEventPreview in interface EventPreview

Parameters:

event - the browser event

Returns:

false to cancel the event

See Also:

DOM.addEventPreview(EventPreview)

onKeyDownPreview

public boolean onKeyDownPreview(char key,
                                int modifiers)

Popups get an opportunity to preview keyboard events before they are passed to a widget contained by the Popup.

Parameters:

key - the key code of the depressed key

modifiers - keyboard modifiers, as specified in KeyboardListener.

Returns:

false to suppress the event

onKeyPressPreview

public boolean onKeyPressPreview(char key,
                                 int modifiers)

Popups get an opportunity to preview keyboard events before they are passed to a widget contained by the Popup.

Parameters:

key - the unicode character pressed

modifiers - keyboard modifiers, as specified in KeyboardListener.

Returns:

false to suppress the event

onKeyUpPreview

public boolean onKeyUpPreview(char key,
                              int modifiers)

Popups get an opportunity to preview keyboard events before they are passed to a widget contained by the Popup.

Parameters:

key - the key code of the released key

modifiers - keyboard modifiers, as specified in KeyboardListener.

Returns:

false to suppress the event

removePopupListener

public void removePopupListener(PopupListener listener)

Description copied from interface: SourcesPopupEvents

Removes a previously added popup listener.

Specified by:

removePopupListener in interface SourcesPopupEvents

Parameters:

listener - the listener interface to remove.

setHeight

public void setHeight(java.lang.String height)

Sets the height of the panel's child widget. If the panel's child widget has not been set, the height passed in will be cached and used to set the height immediately after the child widget is set.

Overrides:

setHeight in class UIObject

Parameters:

height - the object's new height, in CSS units (e.g. "10px", "1em")

setPopupPosition

public void setPopupPosition(int left,
                             int top)

Sets the popup's position relative to the browser's client area. The popup's position may be set before calling show().

Parameters:

left - the left position, in pixels

top - the top position, in pixels

setPopupPositionAndShow

public void setPopupPositionAndShow(PopupPanel.PositionCallback callback)

Sets the popup's position using a PopupPanel.PositionCallback, and shows the popup. The callback allows positioning to be performed based on the offsetWidth and offsetHeight of the popup, which are normally not available until the popup is showing. By positioning the popup before it is shown, the the popup will not jump from its original position to the new position.

Parameters:

callback - the callback to set the position of the popup

See Also:

PopupPanel.PositionCallback.setPosition(int offsetWidth, int offsetHeight)

setTitle

public void setTitle(java.lang.String title)

Description copied from class: UIObject

Sets the title associated with this object. The title is the 'tool-tip' displayed to users when they hover over the object.

Overrides:

setTitle in class UIObject

Parameters:

title - the object's new title

setVisible

public void setVisible(boolean visible)

Sets whether this object is visible.

Overrides:

setVisible in class UIObject

Parameters:

visible - true to show the object, false to hide it

setWidget

public void setWidget(Widget w)

Description copied from class: SimplePanel

Sets this panel's widget. Any existing child widget will be removed.

Overrides:

setWidget in class SimplePanel

Parameters:

w - the panel's new widget, or null to clear the panel

setWidth

public void setWidth(java.lang.String width)

Sets the width of the panel's child widget. If the panel's child widget has not been set, the width passed in will be cached and used to set the width immediately after the child widget is set.

Overrides:

setWidth in class UIObject

Parameters:

width - the object's new width, in CSS units (e.g. "10px", "1em")

show

public void show()

Shows the popup. It must have a child widget before this method is called.

getContainerElement

protected Element getContainerElement()

Description copied from class: SimplePanel

Override this method to specify that an element other than the root element be the container for the panel's child widget. This can be useful when you want to create a simple panel that decorates its contents.

Overrides:

getContainerElement in class SimplePanel

Returns:

the element to be used as the panel's container

getStyleElement

protected Element getStyleElement()

Description copied from class: UIObject

Template method that returns the element to which style names will be applied. By default it returns the root element, but this method may be overridden to apply styles to a child element.

Overrides:

getStyleElement in class UIObject

Returns:

the element to which style names will be applied

onDetach

protected void onDetach()

This method is called when a widget is detached from the browser's document. To receive notification before the PopupPanel is removed from the document, override the Widget.onUnload() method instead.

Overrides:

onDetach in class Widget