/**
* Copyright 2010 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 org.waveprotocol.wave.client.widget.popup;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.dom.client.Style.Visibility;
import com.google.gwt.user.client.ui.RootPanel;
import org.waveprotocol.wave.client.scheduler.ScheduleCommand;
import org.waveprotocol.wave.client.scheduler.Scheduler;
/**
* Class for positioning a popup relative to an element residing in a horizontal or vertical list.
*
*/
public class ListRelativePopupPositioner implements RelativePopupPositioner {
/** Offset to use when positioning popup */
private static final int PIXEL_OFFSET = 10;
/** Strategy instance for vertical-list positioning. */
public static final ListRelativePopupPositioner VERTICAL = new ListRelativePopupPositioner(false);
/** Strategy instance for horizontal-list positioning. */
public static final ListRelativePopupPositioner HORIZONTAL
= new ListRelativePopupPositioner(true);
private final boolean inHorizontalList;
/**
* Create a new ListRelativePopupPostioner.
*
* @param inHorizontalList True if the relative element is in a horizontal list.
*/
private ListRelativePopupPositioner(boolean inHorizontalList) {
this.inHorizontalList = inHorizontalList;
}
/**
* {@inheritDoc}
*/
public void setPopupPositionAndMakeVisible(final Element relative, final Element p) {
ScheduleCommand.addCommand(new Scheduler.Task() {
public void execute() {
Style s = p.getStyle();
int horizontalCenter = RootPanel.get().getOffsetWidth() / 2;
int verticalCenter = RootPanel.get().getOffsetHeight() / 2;
int left = relative.getAbsoluteLeft();
int right = relative.getAbsoluteRight();
int top = relative.getAbsoluteTop();
int bottom = relative.getAbsoluteBottom();
if (inHorizontalList) {
// Place popup above or below relative
if (right > horizontalCenter) {
// Place popup left of relative's right
s.setRight(RootPanel.get().getOffsetWidth() - right + PIXEL_OFFSET, Unit.PX);
if (top < verticalCenter) {
// Place popup below bottom of relative
s.setTop(bottom, Unit.PX);
} else {
// Place popup above top of relative
s.setBottom(RootPanel.get().getOffsetHeight() - top, Unit.PX);
}
} else {
// Place popup right of relative's left
s.setLeft(left + PIXEL_OFFSET, Unit.PX);
if (top < verticalCenter) {
// Place popup below bottom of relative
s.setTop(bottom, Unit.PX);
} else {
// Place popup above top of relative
s.setBottom(RootPanel.get().getOffsetHeight() - top, Unit.PX);
}
}
} else {
// Place popup on left or right side of relative
if (right > horizontalCenter) {
// Place popup left of relative's left
s.setRight(RootPanel.get().getOffsetWidth() - left, Unit.PX);
if (top < verticalCenter) {
// Place popup below top of relative
s.setTop(top + PIXEL_OFFSET, Unit.PX);
} else {
// Place popup above bottom of relative
s.setBottom(RootPanel.get().getOffsetHeight() - bottom + PIXEL_OFFSET, Unit.PX);
}
} else {
// Place popup right of relative's right
s.setLeft(right, Unit.PX);
if (top < verticalCenter) {
// Place popup below top of relative
s.setTop(top + PIXEL_OFFSET, Unit.PX);
} else {
// Place popup above bottom of relative
s.setBottom(RootPanel.get().getOffsetHeight() - bottom + PIXEL_OFFSET, Unit.PX);
}
}
}
p.getStyle().setVisibility(Visibility.VISIBLE);
}
});
}
}