/*
* Ext GWT - Ext for GWT
* Copyright(c) 2007-2009, Ext JS, LLC.
* licensing@extjs.com
*
* http://extjs.com/license
*/
package com.extjs.gxt.ui.client.util;
import com.extjs.gxt.ui.client.core.CompositeElement;
import com.extjs.gxt.ui.client.event.BaseObservable;
import com.extjs.gxt.ui.client.event.EventType;
import com.extjs.gxt.ui.client.event.Events;
import com.extjs.gxt.ui.client.event.PreviewEvent;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.Event.NativePreviewEvent;
import com.google.gwt.user.client.Event.NativePreviewHandler;
/**
* Specialized <code>EventPreview</code>. Provides auto hide support and the
* ability to add elements which should be ignored when auto hide is enabled.
*
* <dt><b>Events:</b></dt>
*
* <dd><b>Add</b> : PreviewEvent(preview, event, target)<br>
* <div>Fires after event preview is added.</div>
* <ul>
* <li>preview : this</li>
* <li>event : the dom event</li>
* <li>target : the target element</li>
* </ul>
* </dd>
*
* <dd><b>Remove</b> : PreviewEvent(preview)<br>
* <div>Fires after event preview has been removed.</div>
* <ul>
* <li>preview : this</li>
* </ul>
* </dd>
*
* <dd><b>KeyPress</b> : PreviewEvent(preview, target, event)<br>
* <div>Fires when a key is pressed while event preview is active.</div>
* <ul>
* <li>preview : this</li>
* <li>target : the target element</li>
* <li>event : event</li>
* </ul>
* </dd> </dt>
*/
public class BaseEventPreview extends BaseObservable implements NativePreviewHandler {
private static int lastX, lastY;
/**
* Returns the last client x value when a base event preview is on top of the
* preview stack.
*
* @return the last client y value
*/
public static int getLastClientX() {
return lastX;
}
/**
* Returns the last xy value when a base event preview is on top of the
* preview stack.
*
* @return the last client x and client y
*/
public static Point getLastXY() {
return new Point(lastX, lastY);
}
/**
* Returns the last client y value when a base event preview is on top of the
* preview stack.
*
* @return the last client y value
*/
public static int getLastClientY() {
return lastY;
}
private CompositeElement ignoreList = new CompositeElement();
private boolean autoHide = true;
private boolean autoHideAllowEvent;
private HandlerRegistration handler;
/**
* Adds this instance to the event preview stack.
*/
public void add() {
if (handler == null) {
handler = Event.addNativePreviewHandler(this);
onAdd();
fireEvent(Events.Add);
}
}
/**
* Returns the ignore list.
*
* @return this list
*/
public CompositeElement getIgnoreList() {
return ignoreList;
}
/**
* Returns true if auto hide is enabled.
*
* @return the auto hide state
*/
public boolean isAutoHide() {
return autoHide;
}
/**
* Returns true if the auto hide event is cancelled.
*
* @return the auto hide event
*/
public boolean isAutoHideAllowEvent() {
return autoHideAllowEvent;
}
public void onPreviewNativeEvent(NativePreviewEvent event) {
Event e = event.getNativeEvent().<Event> cast();
PreviewEvent pe = new PreviewEvent(this, event);
pe.setType(new EventType(e.getTypeInt()));
pe.setEvent(e);
lastX = pe.getClientX();
lastY = pe.getClientY();
if (autoHide && onAutoHidePreview(pe)) {
if (autoHideAllowEvent) {
event.cancel();
}
remove();
}
if (!onPreview(pe)) {
event.cancel();
}
}
/**
* Pushes the event preview to the stop of the stack.
*/
public void push() {
if (handler != null) {
remove();
add();
}
}
/**
* Removes event preview.
*/
public void remove() {
if (handler != null) {
handler.removeHandler();
handler = null;
onRemove();
fireEvent(Events.Remove);
}
}
/**
* True to remove the event preview when the user clicks on an element not it
* the ignore list (default to true).
*
* @param autoHide the auto hide state
*/
public void setAutoHide(boolean autoHide) {
this.autoHide = autoHide;
}
/**
* Sets if the event that removes event preview is cancelled (default to
* true). Only applies when {@link #setAutoHide(boolean)} is true.
*
* @param autoHideAllowEvent true to cancel the event
*/
public void setAutoHideCancelEvent(boolean autoHideAllowEvent) {
this.autoHideAllowEvent = autoHideAllowEvent;
}
/**
* List of elements to be ignored when autoHide is enabled. An example of
* usage would be a menu item that displays a sub menu. When the sub menu is
* displayed, the menu item is added to the ignore list so that the sub menu
* will not close when the mousing over the item.
*
* @param ignoreList the ignore list
*/
public void setIgnoreList(CompositeElement ignoreList) {
this.ignoreList = ignoreList;
}
protected void onAdd() {
}
/**
* Called right before event preview will be removed from auto hide.
*
* @param ce the component event
* @return true to allow auto hide, false to cancel
*/
protected boolean onAutoHide(PreviewEvent ce) {
return true;
}
/**
* Called when a preview event is received and {@link #autoHide} is enabled.
*
* @param ce the component event
* @return true to remove event preview
*/
protected boolean onAutoHidePreview(PreviewEvent ce) {
switch (ce.getType().getEventCode()) {
case Event.ONMOUSEDOWN:
case Event.ONMOUSEUP:
case Event.ONCLICK:
case Event.ONDBLCLICK: {
boolean ignore = getIgnoreList().is(ce.getTarget());
if (!ignore && onAutoHide(ce)) {
return true;
}
}
}
return false;
}
protected void onClick(PreviewEvent pe) {
}
/**
* Called when a preview event is received.
*
* @param pe the component event
* @return true to allow the event
*/
protected boolean onPreview(PreviewEvent pe) {
switch (pe.getType().getEventCode()) {
case Event.ONKEYPRESS:
if (KeyNav.getKeyEvent().getEventCode() == Event.ONKEYPRESS) {
onPreviewKeyPress(pe);
}
break;
case Event.ONKEYDOWN:
if (KeyNav.getKeyEvent().getEventCode() == Event.ONKEYDOWN) {
onPreviewKeyPress(pe);
}
break;
case Event.ONCLICK:
onClick(pe);
}
return true;
}
protected void onPreviewKeyPress(PreviewEvent pe) {
fireEvent(Events.KeyPress, pe);
}
protected void onRemove() {
}
}