/*
* Copyright 2000-2016 Vaadin Ltd.
*
* 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.vaadin.client.ui;
import java.util.ArrayList;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.dom.client.DivElement;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Style;
import com.google.gwt.dom.client.Style.Position;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.dom.client.HasScrollHandlers;
import com.google.gwt.event.dom.client.ScrollEvent;
import com.google.gwt.event.dom.client.ScrollHandler;
import com.google.gwt.event.shared.HandlerRegistration;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.ScrollPanel;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.user.client.ui.impl.FocusImpl;
import com.vaadin.client.BrowserInfo;
/**
* A scrollhandlers similar to {@link ScrollPanel}.
*
*/
public class FocusableScrollPanel extends SimpleFocusablePanel
implements HasScrollHandlers, ScrollHandler {
public FocusableScrollPanel() {
// Prevent IE standard mode bug when a AbsolutePanel is contained.
TouchScrollDelegate.enableTouchScrolling(this, getElement());
Style style = getElement().getStyle();
style.setProperty("zoom", "1");
style.setPosition(Position.RELATIVE);
browserInfo = BrowserInfo.get();
}
private DivElement focusElement;
private BrowserInfo browserInfo;
public FocusableScrollPanel(boolean useFakeFocusElement) {
this();
if (useFakeFocusElement) {
focusElement = Document.get().createDivElement();
}
}
private boolean useFakeFocusElement() {
return focusElement != null;
}
@Override
public void setWidget(Widget w) {
super.setWidget(w);
if (useFakeFocusElement()) {
if (focusElement.getParentElement() == null) {
Style style = focusElement.getStyle();
style.setPosition(Position.FIXED);
style.setTop(0, Unit.PX);
style.setLeft(0, Unit.PX);
if (browserInfo.isIE() || browserInfo.isEdge()) {
// for #15294: artificially hide little bit more the
// focusElement, otherwise IE will make the window to scroll
// into it when focused
style.setLeft(-999, Unit.PX);
}
getElement().appendChild(focusElement);
/* Sink from focusElemet too as focusa and blur don't bubble */
DOM.sinkEvents(focusElement, Event.FOCUSEVENTS);
// revert to original, not focusable
getElement().setPropertyObject("tabIndex", null);
} else {
moveFocusElementAfterWidget();
}
}
}
/**
* Helper to keep focus element always in domChild[1]. Aids testing.
*/
private void moveFocusElementAfterWidget() {
getElement().insertAfter(focusElement, getWidget().getElement());
}
@Override
public void setFocus(boolean focus) {
if (useFakeFocusElement()) {
if (focus) {
FocusImpl.getFocusImplForPanel().focus(focusElement);
} else {
FocusImpl.getFocusImplForPanel().blur(focusElement);
}
} else {
super.setFocus(focus);
}
}
@Override
public void setTabIndex(int tabIndex) {
if (useFakeFocusElement()) {
getElement().setTabIndex(-1);
if (focusElement != null) {
focusElement.setTabIndex(tabIndex);
}
} else {
super.setTabIndex(tabIndex);
}
}
@Override
public HandlerRegistration addScrollHandler(ScrollHandler handler) {
return addDomHandler(handler, ScrollEvent.getType());
}
/**
* Gets the horizontal scroll position.
*
* @return the horizontal scroll position, in pixels
*/
public int getHorizontalScrollPosition() {
return getElement().getScrollLeft();
}
/**
* Gets the vertical scroll position.
*
* @return the vertical scroll position, in pixels
*/
public int getScrollPosition() {
if (getElement().getPropertyJSO("_vScrollTop") != null) {
return getElement().getPropertyInt("_vScrollTop");
} else {
return getElement().getScrollTop();
}
}
/**
* Sets the horizontal scroll position.
*
* @param position
* the new horizontal scroll position, in pixels
*/
public void setHorizontalScrollPosition(int position) {
getElement().setScrollLeft(position);
}
/**
* Sets the vertical scroll position.
*
* @param position
* the new vertical scroll position, in pixels
*/
public void setScrollPosition(int position) {
if (BrowserInfo.get().isAndroidWithBrokenScrollTop()
&& BrowserInfo.get().requiresTouchScrollDelegate()) {
ArrayList<com.google.gwt.dom.client.Element> elements = TouchScrollDelegate
.getElements(getElement());
for (com.google.gwt.dom.client.Element el : elements) {
final Style style = el.getStyle();
style.setProperty("webkitTransform",
"translate3d(0px," + -position + "px,0px)");
}
getElement().setPropertyInt("_vScrollTop", position);
} else {
getElement().setScrollTop(position);
}
}
@Override
public void onScroll(ScrollEvent event) {
Scheduler.get().scheduleDeferred(new ScheduledCommand() {
@Override
public void execute() {
focusElement.getStyle().setTop(getScrollPosition(), Unit.PX);
focusElement.getStyle().setLeft(getHorizontalScrollPosition(),
Unit.PX);
}
});
}
public com.google.gwt.user.client.Element getFocusElement() {
if (useFakeFocusElement()) {
return focusElement.cast();
} else {
return getElement();
}
}
}