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/*
* This library is part of OpenCms -
* the Open Source Content Management System
*
* Copyright (c) Alkacon Software GmbH (http://www.alkacon.com)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* For further information about Alkacon Software, please see the
* company website: http://www.alkacon.com
*
* For further information about OpenCms, please see the
* project website: http://www.opencms.org
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.opencms.gwt.client.ui;
import com.alkacon.geranium.client.I_DescendantResizeHandler;
import org.opencms.gwt.client.ui.css.I_CmsLayoutBundle;
import org.opencms.gwt.client.util.CmsDebugLog;
import org.opencms.gwt.client.util.CmsFocusedScrollingHandler;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.event.dom.client.MouseDownEvent;
import com.google.gwt.event.dom.client.MouseDownHandler;
import com.google.gwt.event.dom.client.ScrollEvent;
import com.google.gwt.event.dom.client.ScrollHandler;
import com.google.gwt.event.logical.shared.HasResizeHandlers;
import com.google.gwt.event.logical.shared.ResizeEvent;
import com.google.gwt.event.logical.shared.ResizeHandler;
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.Event.NativePreviewEvent;
import com.google.gwt.user.client.Event.NativePreviewHandler;
import com.google.gwt.user.client.ui.ScrollPanel;
import com.google.gwt.user.client.ui.Widget;
/**
* Scroll panel implementation allowing focused scrolling.
*/
public class CmsScrollPanel extends ScrollPanel implements HasResizeHandlers, I_DescendantResizeHandler {
/**Inner class for the resize button. */
protected class ResizeButton extends CmsPushButton {
/**
* Default constructor.
*/
public ResizeButton() {
super();
setStyleName(I_CmsLayoutBundle.INSTANCE.buttonCss().resizeButton());
}
/**
* @see com.google.gwt.user.client.ui.CustomButton#onAttach()
*/
@Override
protected void onAttach() {
super.onAttach();
}
/**
* @see com.google.gwt.user.client.ui.CustomButton#onDetach()
*/
@Override
protected void onDetach() {
super.onDetach();
}
}
/**
* Drag and drop event preview handler.
*
* To be used while dragging.
*/
protected class ResizeEventPreviewHandler implements NativePreviewHandler {
/**
* @see com.google.gwt.user.client.Event.NativePreviewHandler#onPreviewNativeEvent(com.google.gwt.user.client.Event.NativePreviewEvent)
*/
public void onPreviewNativeEvent(NativePreviewEvent event) {
Event nativeEvent = Event.as(event.getNativeEvent());
switch (DOM.eventGetType(nativeEvent)) {
case Event.ONMOUSEMOVE:
// dragging
setNewHeight(nativeEvent);
onResizeDescendant();
event.cancel();
break;
case Event.ONMOUSEUP:
m_previewHandlerRegistration.removeHandler();
m_previewHandlerRegistration = null;
break;
case Event.ONKEYDOWN:
break;
case Event.ONMOUSEWHEEL:
//onMouseWheelScroll(nativeEvent);
break;
default:
// do nothing
}
nativeEvent.preventDefault();
nativeEvent.stopPropagation();
}
}
/** The preview handler registration. */
protected HandlerRegistration m_previewHandlerRegistration;
/** The start Y coordination. */
private int m_clientY;
/** The default height. */
private double m_defaultHeight = -1;
/** The prevent outer scrolling handler. */
private CmsFocusedScrollingHandler m_focusedScrollingHandler;
/** The scroll handler registration. */
private HandlerRegistration m_handlerRegistration;
/** Saves if the scrolling panel has the resize button. */
private boolean m_isResize;
/** The start height. */
private double m_oldheight;
/** The button to resize the scrolling panel. */
private ResizeButton m_resize;
/**
* Constructor.
*
* @see com.google.gwt.user.client.ui.ScrollPanel#ScrollPanel()
*/
public CmsScrollPanel() {
m_resize = new ResizeButton();
}
/**
* Constructor to be used by {@link org.opencms.gwt.client.ui.CmsScrollPanelImpl}.
*
* @param root the root element of the widget
* @param scrollabel the scrollable element of the widget
* @param container the container element of the widget
*/
protected CmsScrollPanel(Element root, Element scrollabel, Element container) {
super(root, scrollabel, container);
m_resize = new ResizeButton();
}
/**
* @see com.google.gwt.event.logical.shared.HasResizeHandlers#addResizeHandler(com.google.gwt.event.logical.shared.ResizeHandler)
*/
public HandlerRegistration addResizeHandler(ResizeHandler handler) {
return addHandler(handler, ResizeEvent.getType());
}
/**
* Enables or disables the focused scrolling feature.
* Focused scrolling is enabled by default.
*
* @param enable true to enable the focused scrolling feature
*/
public void enableFocusedScrolling(boolean enable) {
if (enable) {
if (m_handlerRegistration == null) {
m_handlerRegistration = addScrollHandler(new ScrollHandler() {
public void onScroll(ScrollEvent event) {
ensureFocusedScrolling();
}
});
}
} else if (m_handlerRegistration != null) {
m_handlerRegistration.removeHandler();
m_handlerRegistration = null;
}
}
/**
* @see com.alkacon.geranium.client.I_DescendantResizeHandler#onResizeDescendant()
*/
public void onResizeDescendant() {
// not needed
}
/**
* @see com.google.gwt.user.client.ui.SimplePanel#remove(com.google.gwt.user.client.ui.Widget)
*/
@Override
public boolean remove(Widget w) {
if (w == m_resize) {
try {
orphan(m_resize);
} finally {
getElement().removeChild(m_resize.getElement());
}
return true;
} else {
return super.remove(w);
}
}
/**
* Sets the default height of the scrolling panel.
*
* @param height
*/
public void setDefaultHeight(double height) {
m_defaultHeight = height;
}
/**
* Sets the scrollpanel resizeable.
*
* @param resize true if the scrollpanel should be resizeable.
*/
public void setResizable(boolean resize) {
if (resize != m_isResize) {
if (resize) {
getElement().appendChild(m_resize.getElement());
adopt(m_resize);
m_resize.addMouseDownHandler(new MouseDownHandler() {
public void onMouseDown(MouseDownEvent event) {
setStartParameters(event);
CmsDebugLog.getInstance().printLine("Registering preview handler");
if (m_previewHandlerRegistration != null) {
m_previewHandlerRegistration.removeHandler();
}
m_previewHandlerRegistration = Event.addNativePreviewHandler(new ResizeEventPreviewHandler());
}
});
} else {
m_resize.removeFromParent();
}
m_isResize = resize;
}
}
/**
* Ensures the focused scrolling event preview handler is registered.
*/
protected void ensureFocusedScrolling() {
if (m_focusedScrollingHandler == null) {
m_focusedScrollingHandler = CmsFocusedScrollingHandler.installFocusedScrollingHandler(this);
} else if (!m_focusedScrollingHandler.isRegistered()) {
m_focusedScrollingHandler.register();
}
}
/**
* @see com.google.gwt.user.client.ui.ScrollPanel#onAttach()
*/
@Override
protected void onAttach() {
super.onAttach();
if (m_isResize) {
m_resize.onAttach();
}
}
/**
* @see com.google.gwt.user.client.ui.ScrollPanel#onDetach()
*/
@Override
protected void onDetach() {
super.onDetach();
if (m_isResize) {
m_resize.onDetach();
}
}
/**
* Executed on mouse move while dragging.
*
* @param event the event
*/
protected void setNewHeight(Event event) {
double newheight = m_oldheight + (event.getClientY() - m_clientY);
if (m_defaultHeight != -1) {
if (newheight < m_defaultHeight) {
newheight = m_defaultHeight;
}
}
ResizeEvent.fire(this, getOffsetWidth(), (int)newheight);
getElement().getStyle().setHeight(newheight, Unit.PX);
}
/**
* Sets the start parameters of the resize event.
*
* @param event
*/
protected void setStartParameters(MouseDownEvent event) {
m_oldheight = Double.parseDouble(getElement().getStyle().getHeight().replace("px", ""));
m_clientY = event.getClientY();
}
}