org.gwt.advanced.client.ui.widget

Class ListPopupPanel

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

org.gwt.advanced.client.ui.widget.ListPopupPanel

All Implemented Interfaces:

com.google.gwt.event.dom.client.HasChangeHandlers, com.google.gwt.event.logical.shared.HasAttachHandlers, com.google.gwt.event.logical.shared.HasCloseHandlers<com.google.gwt.user.client.ui.PopupPanel>, com.google.gwt.event.shared.HasHandlers, com.google.gwt.user.client.EventListener, com.google.gwt.user.client.EventPreview, com.google.gwt.user.client.ui.AcceptsOneWidget, com.google.gwt.user.client.ui.HasAnimation, com.google.gwt.user.client.ui.HasOneWidget, com.google.gwt.user.client.ui.HasVisibility, com.google.gwt.user.client.ui.HasWidgets, com.google.gwt.user.client.ui.HasWidgets.ForIsWidget, com.google.gwt.user.client.ui.IsWidget, com.google.gwt.user.client.ui.SourcesPopupEvents, Iterable<com.google.gwt.user.client.ui.Widget>, AdvancedWidget

public class ListPopupPanel
extends com.google.gwt.user.client.ui.PopupPanel
implements AdvancedWidget, com.google.gwt.event.dom.client.HasChangeHandlers

This widget displays a scrollable list of items.

Don't try to use it directly. It's just for the combo box widget.

Since:

1.2.0

Author:

Sergey Skladchikov

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	ListPopupPanel.ClickSpyHandler This handler spies for click events if the list is opened and hides it if there is any element clicked excepting the combo box elements and list elements.
protected class	ListPopupPanel.ItemClickHandler This is a click handler required to dispatch click events.
protected class	ListPopupPanel.ListMouseHandler This listener is required to handle mouse moving events over the list.
protected class	ListPopupPanel.ListScrollHandler This scroll handler is invoked on any scrolling event caotured by the items list.
protected class	ListPopupPanel.ListWindowResizeHandler This handler is invoked on window resize and changes opened list popup panel position according to new coordinates of the ComboBox.

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

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

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

com.google.gwt.user.client.ui.UIObject.DebugIdImpl, com.google.gwt.user.client.ui.UIObject.DebugIdImplEnabled

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

com.google.gwt.user.client.ui.HasWidgets.ForIsWidget

Field Summary

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

DEBUG_ID_PREFIX

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ListPopupPanel(ComboBox selectionTextBox) Creates an instance of this class and sets the parent combo box value.

Method Summary

Methods

Modifier and Type	Method and Description
com.google.gwt.event.shared.HandlerRegistration	addChangeHandler(com.google.gwt.event.dom.client.ChangeHandler handler) This method adds a handler that will be invoked on choice.
protected void	adjustSize() Adjusts drop down list sizes to make it take optimal area on the screen.
protected com.google.gwt.user.client.ui.FocusPanel	adoptItemWidget(com.google.gwt.user.client.ui.Widget widget) This method wraps the specified widget into the focus panel and adds necessary listeners.
void	display() Deprecated. you don't have to invoke this method to display the widget any more
void	ensureVisible(com.google.gwt.user.client.ui.Widget item) Makes the item visible in the list according to the check done by the isItemVisible(int) method.
protected void	fillList() Fills the list of items starting from the current position and ending with rendering limits See {2link #isRenderingLimitReached()} for additional details since it's used in the body of this method.
protected ComboBox	getComboBox() Getter for property 'comboBox'.
DropDownPosition	getDropDownPosition() Gets applied position of the drop down list.
int	getHighlightRow() Gets a currently highlight row.
com.google.gwt.user.client.ui.Widget	getItem(int index) Gets an item by its index If index < 0 or index >= getItemCount() it throws an exception.
protected com.google.gwt.event.dom.client.ClickHandler	getItemClickHandler() Getter for property 'itemClickHandler'.
int	getItemCount() This method gets an actual number of items displayed in the drop down.
int	getItemIndex(com.google.gwt.user.client.ui.Widget item) Gets an item index if it's displayed in the drop down list.
protected com.google.gwt.user.client.ui.FlowPanel	getList() Getter for property 'list'.
com.google.gwt.event.dom.client.ScrollHandler	getListScrollHandler() Getter for property 'listScrollHandler'.
protected ListPopupPanel.ListMouseHandler	getMouseEventsHandler() Getter for property 'mouseEventsListener'.
com.google.gwt.user.client.ui.ScrollPanel	getScrollPanel() Getter for property 'scrollPanel'.
int	getStartItemIndex()
int	getVisibleRows() Gets a number of visible rows.
void	hide()
boolean	isHidden() Getter for property 'hidden'.
boolean	isItemVisible(int index) Checks whether the specified item is visible in the scroll area.
protected boolean	isLazyRenderingEnabled() Checks whether the lazy rendering option is enabled.
protected boolean	isRenderingLimitReached(int previouslyRenderedRows) This method checks whether the limit of displayed items reached.
protected void	prepareList() This method prepares the list of items for displaying.
protected void	resetPosition() Chooses and sets a mostly appropriate position of the drop down list
protected void	selectRow(int newRow) This method higlights a selected row.
void	setDropDownPosition(DropDownPosition dropDownPosition) Sets applied position of the drop down list.
protected void	setHidden(boolean hidden) Setter for property 'hidden'.
protected void	setHighlightRow(int row) Sets the highlight row number.
protected void	setLazyRenderingEnabled(boolean lazyRenderingEnabled) Enables or disables lazy rendering option.
void	setStartItemIndex(int index) Sets an item index that must be displayed on top.
void	setVisibleRows(int visibleRows) Sets visible rows number.
void	show()

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

addAutoHidePartner, addCloseHandler, addPopupListener, center, getContainerElement, getGlassElement, getGlassStyleName, getOffsetHeight, getOffsetWidth, getPopupLeft, getPopupTop, getStyleElement, getTitle, hide, isAnimationEnabled, isAutoHideEnabled, isAutoHideOnHistoryEventsEnabled, isGlassEnabled, isModal, isPreviewingAllNativeEvents, isShowing, isVisible, onEventPreview, onKeyDownPreview, onKeyPressPreview, onKeyUpPreview, onPreviewNativeEvent, onUnload, removeAutoHidePartner, removePopupListener, setAnimationEnabled, setAutoHideEnabled, setAutoHideOnHistoryEventsEnabled, setGlassEnabled, setGlassStyleName, setHeight, setModal, setPopupPosition, setPopupPositionAndShow, setPreviewingAllNativeEvents, setTitle, setVisible, setWidget, setWidth, showRelativeTo

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

add, getWidget, iterator, remove, setWidget

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

add, adopt, adopt, clear, disown, doAttachChildren, doDetachChildren, orphan, remove

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

addAttachHandler, addBitlessDomHandler, addDomHandler, addHandler, asWidget, asWidgetOrNull, createHandlerManager, delegateEvent, fireEvent, getHandlerCount, getLayoutData, getParent, isAttached, isOrWasAttached, onAttach, onBrowserEvent, onDetach, onLoad, removeFromParent, setLayoutData, sinkEvents

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

addStyleDependentName, addStyleName, ensureDebugId, ensureDebugId, ensureDebugId, getAbsoluteLeft, getAbsoluteTop, getElement, getStyleName, getStyleName, getStylePrimaryName, getStylePrimaryName, isVisible, onEnsureDebugId, removeStyleDependentName, removeStyleName, resolvePotentialElement, setElement, setElement, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setVisible, sinkBitlessEvent, toString, unsinkEvents

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.google.gwt.event.shared.HasHandlers

fireEvent

Constructor Detail

ListPopupPanel

protected ListPopupPanel(ComboBox selectionTextBox)

Creates an instance of this class and sets the parent combo box value.

Parameters:

selectionTextBox - is a selection box value.

Method Detail

addChangeHandler

public com.google.gwt.event.shared.HandlerRegistration addChangeHandler(com.google.gwt.event.dom.client.ChangeHandler handler)

This method adds a handler that will be invoked on choice.

Specified by:

addChangeHandler in interface com.google.gwt.event.dom.client.HasChangeHandlers

Parameters:

handler - is a handler to be added.

isHidden

public boolean isHidden()

Getter for property 'hidden'.

Returns:

Value for property 'hidden'.

getHighlightRow

public int getHighlightRow()

Gets a currently highlight row.

Note that it may not be equal to the selected row index in the model.

Returns:

a row number that is currently highlight.

getItemCount

public int getItemCount()

This method gets an actual number of items displayed in the drop down.

Returns:

an item count.

getItem

public com.google.gwt.user.client.ui.Widget getItem(int index)

Gets an item by its index

If index < 0 or index >= getItemCount() it throws an exception.

Parameters:

index - is an index of the item to get.

Returns:

a found item.

Throws:

IndexOutOfBoundsException - if index is invalid.

getItemIndex

public int getItemIndex(com.google.gwt.user.client.ui.Widget item)

Gets an item index if it's displayed in the drop down list.

Otherwise returns -1.

Parameters:

item - an item that is required to return.

Returns:

an item index value or -1.

setHighlightRow

protected void setHighlightRow(int row)

Sets the highlight row number.

Parameters:

row - is a row number to become highlight.

isItemVisible

public boolean isItemVisible(int index)

Checks whether the specified item is visible in the scroll area.

The result is true if whole item is visible.

Parameters:

index - is an index of the item.

Returns:

a result of check.

ensureVisible

public void ensureVisible(com.google.gwt.user.client.ui.Widget item)

Makes the item visible in the list according to the check done by the isItemVisible(int) method.

Parameters:

item - is an item to check.

hide

public void hide()

Overrides:

hide in class com.google.gwt.user.client.ui.PopupPanel

show

public void show()

Overrides:

show in class com.google.gwt.user.client.ui.PopupPanel

getVisibleRows

public int getVisibleRows()

Gets a number of visible rows.

Values <= 0 interpreted as undefined.

Returns:

a visible rows to be displayed without scrolling.

setVisibleRows

public void setVisibleRows(int visibleRows)

Sets visible rows number.

You can pass a value <= 0. It will mean that this parameter in undefined.

Parameters:

visibleRows - is a number of rows to be displayed without scrolling.

setStartItemIndex

public void setStartItemIndex(int index)

Sets an item index that must be displayed on top.

If the item is outside the currently visible area the list will be scrolled down to this item.

Parameters:

index - is an index of the element to display.

getStartItemIndex

public int getStartItemIndex()

getDropDownPosition

public DropDownPosition getDropDownPosition()

Gets applied position of the drop down list.

Returns:

a drop down list position value.

setDropDownPosition

public void setDropDownPosition(DropDownPosition dropDownPosition)

Sets applied position of the drop down list.

Being set the drop down is immediately applied if the list is opened.

Parameters:

dropDownPosition - is a drop down list position value.

adjustSize

protected void adjustSize()

Adjusts drop down list sizes to make it take optimal area on the screen.

resetPosition

protected void resetPosition()

Chooses and sets a mostly appropriate position of the drop down list

display

public void display()

Deprecated. you don't have to invoke this method to display the widget any more

This method displayes a widget.

Specified by:

display in interface AdvancedWidget

isLazyRenderingEnabled

protected boolean isLazyRenderingEnabled()

Checks whether the lazy rendering option is enabled.

Returns:

a result of check.

setLazyRenderingEnabled

protected void setLazyRenderingEnabled(boolean lazyRenderingEnabled)

Enables or disables lazy rendering option.

If this option is enabled the list displays only several items on lazily reders other ones on scroll down.

By default lazy rendering is disabled. Switch it on for really large (over 500 items) lists only.

Parameters:

lazyRenderingEnabled - is an option value.

prepareList

protected void prepareList()

This method prepares the list of items for displaying.

fillList

protected void fillList()

Fills the list of items starting from the current position and ending with rendering limits

See {2link #isRenderingLimitReached()} for additional details since it's used in the body of this method.

isRenderingLimitReached

protected boolean isRenderingLimitReached(int previouslyRenderedRows)

This method checks whether the limit of displayed items reached.

It takes into account different aspects including setting of the widget, geometrical size of the drop down list and selected value that must be displayed.

This method optimally chooses a number of items to display.

Parameters:

previouslyRenderedRows - is a number of rows previously loaded in the list (items count before filling the list).

Returns:

a result of check.

selectRow

protected void selectRow(int newRow)

This method higlights a selected row.

Parameters:

newRow - a row for selection.

adoptItemWidget

protected com.google.gwt.user.client.ui.FocusPanel adoptItemWidget(com.google.gwt.user.client.ui.Widget widget)

This method wraps the specified widget into the focus panel and adds necessary listeners.

Parameters:

widget - is an item widget to be wraped.

Returns:

a focus panel adopted for displaying.

setHidden

protected void setHidden(boolean hidden)

Setter for property 'hidden'.

Parameters:

hidden - Value to set for property 'hidden'.

getComboBox

protected ComboBox getComboBox()

Getter for property 'comboBox'.

Returns:

Value for property 'comboBox'.

getList

protected com.google.gwt.user.client.ui.FlowPanel getList()

Getter for property 'list'.

Returns:

Value for property 'list'.

getScrollPanel

public com.google.gwt.user.client.ui.ScrollPanel getScrollPanel()

Getter for property 'scrollPanel'.

Returns:

Value for property 'scrollPanel'.

getItemClickHandler

protected com.google.gwt.event.dom.client.ClickHandler getItemClickHandler()

Getter for property 'itemClickHandler'.

Returns:

Value for property 'itemClickHandler'.

getMouseEventsHandler

protected ListPopupPanel.ListMouseHandler getMouseEventsHandler()

Getter for property 'mouseEventsListener'.

Returns:

Value for property 'mouseEventsListener'.

getListScrollHandler

public com.google.gwt.event.dom.client.ScrollHandler getListScrollHandler()

Getter for property 'listScrollHandler'.

Returns:

Value for property 'listScrollHandler'.