/**
* Sencha GXT 3.1.0-beta - Sencha for GWT
* Copyright(c) 2007-2014, Sencha, Inc.
* licensing@sencha.com
*
* http://www.sencha.com/products/gxt/license/
*/
package com.sencha.gxt.core.client.util;
import com.google.gwt.dom.client.Element;
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;
import com.sencha.gxt.core.client.dom.CompositeElement;
/**
* Specialized <code>EventPreview</code>. Provides auto hide support and the
* ability to add elements which should be ignored when auto hide is enabled.
*/
public class BaseEventPreview 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 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;
}
/**
* 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);
}
private CompositeElement ignoreList = new CompositeElement();
private boolean autoHide = true;
private boolean autoHideAllowEvent;
private HandlerRegistration handler;
private int keyEvent;
public BaseEventPreview() {
keyEvent = KeyNav.getKeyEvent();
}
/**
* Adds this instance to the event preview stack.
*/
public void add() {
if (handler == null) {
handler = Event.addNativePreviewHandler(this);
onAdd();
}
}
/**
* 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().cast();
lastX = e.getClientX();
lastY = e.getClientY();
if (autoHide && onAutoHidePreview(event)) {
if (autoHideAllowEvent) {
event.cancel();
}
remove();
}
if (!onPreview(event)) {
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();
}
}
/**
* 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;
}
/**
* Sets the key event type used to determine key presses for
* {@link #onPreview(Event.NativePreviewEvent)}. By default, the key press
* event is determined using {@link KeyNav#getKeyEvent()}.
*
* @param type the key event type
*/
public void setKeyEvent(int type) {
keyEvent = type;
}
protected void onAdd() {
}
/**
* Called right before event preview will be removed from auto hide.
*
* @param pe the preview event
* @return true to allow auto hide, false to cancel
*/
protected boolean onAutoHide(NativePreviewEvent pe) {
return true;
}
/**
* Called when a preview event is received and {@link #autoHide} is enabled.
*
* @param pe the preview event
* @return true to remove event preview
*/
protected boolean onAutoHidePreview(NativePreviewEvent pe) {
int type = pe.getTypeInt();
switch (type) {
case Event.ONMOUSEDOWN:
case Event.ONMOUSEUP:
case Event.ONCLICK:
case Event.ONDBLCLICK: {
boolean ignore = getIgnoreList().is((Element) pe.getNativeEvent().getEventTarget().cast());
if (!ignore && onAutoHide(pe)) {
return true;
}
}
}
return false;
}
protected void onClick(NativePreviewEvent pe) {
}
/**
* Called when a preview event is received.
*
* @param pe the preview event
* @return true to allow the event
*/
protected boolean onPreview(NativePreviewEvent pe) {
if (pe.getTypeInt() == keyEvent) {
onPreviewKeyPress(pe);
return true;
}
switch (pe.getTypeInt()) {
case Event.ONCLICK:
onClick(pe);
}
return true;
}
/**
* Called when a preview key press event is received.
*
* @param pe the preview event
*/
protected void onPreviewKeyPress(NativePreviewEvent pe) {
}
protected void onRemove() {
}
}