com.google.gwt.user.client.impl.HistoryImpl Maven / Gradle / Ivy
/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.user.client.impl;
import com.google.gwt.event.logical.shared.HasValueChangeHandlers;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.event.logical.shared.ValueChangeHandler;
import com.google.gwt.event.shared.GwtEvent;
import com.google.gwt.event.shared.HandlerManager;
import com.google.gwt.event.shared.HandlerRegistration;
/**
* Native implementation associated with
* {@link com.google.gwt.user.client.History}. User classes should not use this
* class directly.
*
*
* This base version uses the HTML5 standard window.onhashchange event to
* determine when the URL hash identifier changes.
*
*/
public class HistoryImpl implements HasValueChangeHandlers {
private static String token = "";
public static String getToken() {
return (token == null) ? "" : token;
}
/**
* Sets whether the IE6 history implementation will update the URL hash when
* creating a new item. This should be used only for applications with large
* DOM structures that are suffering from performance problems when creating a
* new history item on IE6 and 7.
*
* @deprecated This is no longer necessary, as the underlying performance
* problem has been solved. It is now a no-op.
*/
@Deprecated
@SuppressWarnings("unused")
public static void setUpdateHashOnIE6(boolean updateHash) {
}
protected static void setToken(String token) {
HistoryImpl.token = token;
}
private HandlerManager handlers = new HandlerManager(null);
/**
* Adds a {@link ValueChangeEvent} handler to be informed of changes to the
* browser's history stack.
*
* @param handler the handler
*/
public HandlerRegistration addValueChangeHandler(
ValueChangeHandler handler) {
return handlers.addHandler(ValueChangeEvent.getType(), handler);
}
public void fireEvent(GwtEvent event) {
handlers.fireEvent(event);
}
/**
* Fires the {@link ValueChangeEvent} to all handlers with the given tokens.
*/
public void fireHistoryChangedImpl(String newToken) {
ValueChangeEvent.fire(this, newToken);
}
public HandlerManager getHandlers() {
return handlers;
}
public native boolean init() /*-{
var token = '';
// Get the initial token from the url's hash component.
var hash = $wnd.location.hash;
if (hash.length > 0) {
token = [email protected]::decodeFragment(Ljava/lang/String;)(hash.substring(1));
}
@com.google.gwt.user.client.impl.HistoryImpl::setToken(Ljava/lang/String;)(token);
var historyImpl = this;
var oldHandler = $wnd.onhashchange;
$wnd.onhashchange = $entry(function() {
var token = '', hash = $wnd.location.hash;
if (hash.length > 0) {
token = [email protected]::decodeFragment(Ljava/lang/String;)(hash.substring(1));
}
[email protected]::newItemOnEvent(Ljava/lang/String;)(token);
if (oldHandler) {
oldHandler();
}
});
return true;
}-*/;
public final void newItem(String historyToken, boolean issueEvent) {
historyToken = (historyToken == null) ? "" : historyToken;
if (!historyToken.equals(getToken())) {
setToken(historyToken);
nativeUpdate(historyToken);
if (issueEvent) {
fireHistoryChangedImpl(historyToken);
}
}
}
public final void newItemOnEvent(String historyToken) {
historyToken = (historyToken == null) ? "" : historyToken;
if (!historyToken.equals(getToken())) {
setToken(historyToken);
nativeUpdateOnEvent(historyToken);
fireHistoryChangedImpl(historyToken);
}
}
protected native String decodeFragment(String encodedFragment) /*-{
// decodeURI() does *not* decode the '#' character.
return decodeURI(encodedFragment.replace("%23", "#"));
}-*/;
protected native String encodeFragment(String fragment) /*-{
// encodeURI() does *not* encode the '#' character.
return encodeURI(fragment).replace("#", "%23");
}-*/;
/**
* The standard updateHash implementation assigns to location.hash() with an
* encoded history token.
*/
protected native void nativeUpdate(String historyToken) /*-{
$wnd.location.hash = [email protected]::encodeFragment(Ljava/lang/String;)(historyToken);
}-*/;
@SuppressWarnings("unused")
protected void nativeUpdateOnEvent(String historyToken) {
// Do nothing, the hash is already updated.
}
}