Java tutorial
/* * Copyright 2009 Sven Meier * * 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 wicketdnd; import org.apache.wicket.Component; import org.apache.wicket.MarkupContainer; import org.apache.wicket.Page; import org.apache.wicket.ajax.AjaxRequestTarget; import org.apache.wicket.behavior.Behavior; import org.apache.wicket.markup.ComponentTag; import org.apache.wicket.markup.html.IHeaderResponse; import org.apache.wicket.protocol.http.PageExpiredException; import org.apache.wicket.request.Request; import wicketdnd.util.CollectionFormattable; import wicketdnd.util.MarkupIdVisitor; import java.util.Set; /** * A source of drags. * * @see #getTypes() * @see #onBeforeDrop(Component, Transfer) * @see #onAfterDrop(AjaxRequestTarget, Transfer) * * @author Sven Meier */ public class DragSource extends Behavior { private static final long serialVersionUID = 1L; private Component component; private String selector = Transfer.UNDEFINED; private String initiateSelector = Transfer.UNDEFINED; private String cloneSelector = Transfer.UNDEFINED; private Set<Operation> operations; /** * Create a source of drags. * * @param operations * allowed operations * * @see #getOperations() */ public DragSource(Operation... operations) { this(Operation.of(operations)); } /** * Create a source of drags. * * @param operations * allowed operations * * @see #getOperations() */ public DragSource(Set<Operation> operations) { this.operations = operations; } /** * Get supported types for a transfer. * * @return transfers * @see Transfer#getType() */ public String[] getTypes() { return new String[] { Transfer.ANY }; } /** * Allow drag on elements matching the given selector. * * Make sure all matching elements are configured to output their markup id. * * @param selector * element selector * @see Component#setOutputMarkupId(boolean) */ public DragSource drag(String selector) { this.selector = selector; if (this.initiateSelector.equals(Transfer.UNDEFINED)) { this.initiateSelector = selector; } if (this.cloneSelector.equals(Transfer.UNDEFINED)) { this.cloneSelector = selector; } return this; } /** * Initiate drag on elements matching the given selector. * * @param selector * element selector */ public DragSource initiate(String selector) { this.initiateSelector = selector; return this; } /** * Clone drag on elements matching the given selector. * * @param selector * element selector */ public DragSource clone(String selector) { this.cloneSelector = selector; return this; } @Override public final void bind(Component component) { this.component = component; component.setOutputMarkupId(true); } /** * Get the identifying path of this drag source. * * @return path in page */ public String getPath() { return component.getPageRelativePath(); } /** * Get the id of this behavior. * * @return id */ public int getBehaviorId() { return component.getBehaviorId(this); } @Override public final void renderHead(Component c, IHeaderResponse response) { super.renderHead(c, response); renderDragHead(response); } private void renderDragHead(IHeaderResponse response) { response.renderJavaScriptReference(Transfer.JS); final String id = component.getMarkupId(); final String path = component.getPageRelativePath(); int behavior = component.getBehaviorId(this); String initJS = String.format( "wicketdnd.dragSource('%s','%s','%s', %s,%s,{'select':'%s','initiate':'%s','clone':'%s'});", id, behavior, path, new CollectionFormattable(getOperations()), new CollectionFormattable(getTypes()), selector, initiateSelector, cloneSelector); response.renderOnDomReadyJavaScript(initJS); } @Override public void onComponentTag(Component component, ComponentTag tag) { super.onComponentTag(component, tag); tag.append("class", "dnd-drag-source", " "); } /** * Get supported operations. * * @return operations * @see Transfer#getOperation() */ public Set<Operation> getOperations() { return operations; } final boolean hasOperation(Operation operation) { return getOperations().contains(operation); } final void beforeDrop(Request request, Transfer transfer) throws Reject { Component drag = getDrag(request); onBeforeDrop(drag, transfer); } final void afterDrop(AjaxRequestTarget target, Transfer transfer) { onAfterDrop(target, transfer); } /** * Notification that a drop is about to happen - any implementation should * set the data on the given transfer or reject it. * * The default implementation uses the component's model object as transfer * data. * * @param drag * component to get data from * @param operation * the drag's operation * @param transfer * the transfer * @throws Reject * may reject the drop * @see Transfer#setData(Object) * @see Transfer#reject() */ public void onBeforeDrop(Component drag, Transfer transfer) throws Reject { transfer.setData(drag.getDefaultModelObject()); } /** * Notification that a drop happened of one of this source's transfer datas. * * The default implementation does nothing. * * @param target * initiating request target * @param transfer * the transfer */ public void onAfterDrop(AjaxRequestTarget target, Transfer transfer) { } private Component getDrag(Request request) { String drag = request.getRequestParameters().getParameterValue("drag").toString(); return MarkupIdVisitor.getComponent((MarkupContainer) component, drag); } /** * Get the drag source of the given request. * * @param request * request on which a drag happened * @return drag source */ final static DragSource read(Page page, Request request) { String path = request.getRequestParameters().getParameterValue("path").toString(); Component component = page.get(path); if (component == null) { throw new PageExpiredException("No drag source found " + path); } int behavior = request.getRequestParameters().getParameterValue("behavior").toInt(); return (DragSource) component.getBehaviorById(behavior); } }