com.googlecode.wicket.kendo.ui.interaction.draggable.DraggableBehavior.java Source code

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.googlecode.wicket.kendo.ui.interaction.draggable;

import org.apache.wicket.Component;
import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.attributes.CallbackParameter;
import org.apache.wicket.util.lang.Args;
import org.apache.wicket.util.visit.IVisit;
import org.apache.wicket.util.visit.IVisitor;
import org.apache.wicket.util.visit.Visits;

import com.googlecode.wicket.jquery.core.IJQueryWidget.JQueryWidget;
import com.googlecode.wicket.jquery.core.JQueryEvent;
import com.googlecode.wicket.jquery.core.Options;
import com.googlecode.wicket.jquery.core.ajax.IJQueryAjaxAware;
import com.googlecode.wicket.jquery.core.ajax.JQueryAjaxBehavior;
import com.googlecode.wicket.jquery.core.utils.RequestCycleUtils;
import com.googlecode.wicket.kendo.ui.KendoUIBehavior;
import com.googlecode.wicket.kendo.ui.interaction.droppable.DroppableBehavior;

/**
 * Provides a {@value #METHOD} behavior<br/>
 * <b>Note:</b> This behavior should be attached directly to the component to be dragged. Therefore the 'filter' option will not work here.<br/>
 * <b>Warning:</b> not thread-safe: the instance of this behavior should only be used once
 *
 * @author Sebastien Briquet - sebfz1
 */
public class DraggableBehavior extends KendoUIBehavior implements IJQueryAjaxAware {
    private static final long serialVersionUID = 1L;

    public static final String METHOD = "kendoDraggable";

    public static final String CSS_HIDE = "kendoDraggable-hide";
    public static final String CSS_CLONE = "kendoDraggable-clone";

    /** default hint */
    public static final String FCN_HINT = "function(element) { return element.clone().addClass('" + CSS_CLONE
            + "'); }";

    private final IDraggableListener listener;
    private JQueryAjaxBehavior onDragStartAjaxBehavior;
    private JQueryAjaxBehavior onDragStopAjaxBehavior = null;
    private JQueryAjaxBehavior onDragCancelAjaxBehavior = null;

    private Component component = null;

    /**
     * Constructor
     * @param listener the {@link IDraggableListener}
     */
    public DraggableBehavior(IDraggableListener listener) {
        this(null, new Options(), listener);
    }

    /**
     * Constructor
     * 
     * @param options the {@link Options}
     * @param listener the {@link IDraggableListener}
     */
    public DraggableBehavior(Options options, IDraggableListener listener) {
        this(null, options, listener);
    }

    /**
     * Constructor
     * 
     * @param selector the html selector (ie: "#myId")
     * @param listener the {@link IDraggableListener}
     */
    protected DraggableBehavior(String selector, IDraggableListener listener) {
        this(selector, new Options(), listener);
    }

    /**
     * Constructor
     * 
     * @param selector the html selector (ie: "#myId")
     * @param options the {@link Options}
     * @param listener the {@link IDraggableListener}
     */
    protected DraggableBehavior(String selector, Options options, IDraggableListener listener) {
        super(selector, METHOD, options);

        this.listener = Args.notNull(listener, "listener");
    }

    // Methods //

    @Override
    public void bind(Component component) {
        super.bind(component);

        if (this.component != null) {
            throw new WicketRuntimeException("Behavior is already bound to another component.");
        }

        this.component = component; // warning, not thread-safe: the instance of this behavior should only be used once

        if (this.selector == null) {
            this.selector = JQueryWidget.getSelector(this.component);
        }

        this.onDragStartAjaxBehavior = this.newOnDragStartAjaxBehavior(this);
        this.component.add(this.onDragStartAjaxBehavior);

        this.onDragStopAjaxBehavior = this.newOnDragStopAjaxBehavior(this);
        this.component.add(this.onDragStopAjaxBehavior);

        // this event is not enabled by default to prevent unnecessary server round-trips.
        if (this.listener.isCancelEventEnabled()) {
            this.onDragCancelAjaxBehavior = this.newOnDragCancelAjaxBehavior(this);
            this.component.add(this.onDragCancelAjaxBehavior);
        }
    }

    // Events //

    @Override
    public void onConfigure(Component component) {
        super.onConfigure(component);

        // options //

        if (this.getOption("hint") == null) {
            this.setOption("hint", FCN_HINT);
        }

        // behaviors //

        this.setOption("dragstart", this.onDragStartAjaxBehavior.getCallbackFunction());
        this.setOption("dragend", this.onDragStopAjaxBehavior.getCallbackFunction());

        if (this.onDragCancelAjaxBehavior != null) {
            this.setOption("dragcancel", this.onDragCancelAjaxBehavior.getCallbackFunction());
        }
    }

    @Override
    public void onAjax(AjaxRequestTarget target, JQueryEvent event) {
        if (event instanceof DraggableEvent) {
            DraggableEvent e = (DraggableEvent) event;

            if (e instanceof DragStartEvent) {
                // register to all DroppableBehavior(s) //
                Visits.visit(target.getPage(), this.newDroppableBehaviorVisitor());

                this.listener.onDragStart(target, e.getTop(), e.getLeft());
            }

            else if (e instanceof DragStopEvent) {
                this.listener.onDragStop(target, e.getTop(), e.getLeft());
            }

            else if (e instanceof DragCancelEvent) {
                this.listener.onDragCancel(target, e.getTop(), e.getLeft());
            }
        }
    }

    // Factories //

    /**
     * Gets a new {@link DroppableBehavior} visitor.<br/>
     * This {@link IVisitor} is responsible for register the {@link DroppableBehavior} to this {@link DraggableBehavior}
     *
     * @return a {@link IVisitor}
     */
    private IVisitor<Component, ?> newDroppableBehaviorVisitor() {
        return new IVisitor<Component, Void>() {

            @Override
            public void component(Component component, IVisit<Void> visit) {
                for (DroppableBehavior behavior : component.getBehaviors(DroppableBehavior.class)) {
                    behavior.setDraggable(DraggableBehavior.this.component);
                }
            }
        };
    }

    /**
     * Gets a new {@link JQueryAjaxBehavior} that will be wired to the 'dragstart' event
     *
     * @param source the {@link IJQueryAjaxAware}
     * @return a new {@code OnDragStartAjaxBehavior} by default
     */
    protected JQueryAjaxBehavior newOnDragStartAjaxBehavior(IJQueryAjaxAware source) {
        return new OnDragStartAjaxBehavior(source);
    }

    /**
     * Gets a new {@link JQueryAjaxBehavior} that will be wired to the 'dragend' event
     *
     * @param source the {@link IJQueryAjaxAware}
     * @return a new {@code OnDragStopAjaxBehavior} by default
     */
    protected JQueryAjaxBehavior newOnDragStopAjaxBehavior(IJQueryAjaxAware source) {
        return new OnDragStopAjaxBehavior(source);
    }

    /**
     * Gets a new {@link JQueryAjaxBehavior} that will be wired to the 'dragcancel' event
     *
     * @param source the {@link IJQueryAjaxAware}
     * @return a new {@code OnDragCancelAjaxBehavior} by default
     */
    protected JQueryAjaxBehavior newOnDragCancelAjaxBehavior(IJQueryAjaxAware source) {
        return new OnDragCancelAjaxBehavior(source);
    }

    // Ajax classes //

    /**
     * Provides a {@link JQueryAjaxBehavior} that aims to be wired to the 'dragstart' event
     */
    protected static class OnDragStartAjaxBehavior extends JQueryAjaxBehavior {
        private static final long serialVersionUID = 1L;

        public OnDragStartAjaxBehavior(IJQueryAjaxAware source) {
            super(source);
        }

        @Override
        protected CallbackParameter[] getCallbackParameters() {
            return new CallbackParameter[] { CallbackParameter.context("e"), // lf
                    CallbackParameter.resolved("top", "e.sender.hintOffset.top | 0"), // cast to int, no rounding
                    CallbackParameter.resolved("left", "e.sender.hintOffset.left | 0") // cast to int, no rounding
            };
        }

        @Override
        public CharSequence getCallbackFunctionBody(CallbackParameter... parameters) {
            String statement = "this.element.addClass('" + CSS_HIDE + "');";
            return statement + super.getCallbackFunctionBody(parameters);
        }

        @Override
        protected JQueryEvent newEvent() {
            return new DragStartEvent();
        }
    }

    /**
     * Provides a {@link JQueryAjaxBehavior} that aims to be wired to the 'dragend' event
     */
    protected static class OnDragStopAjaxBehavior extends JQueryAjaxBehavior {
        private static final long serialVersionUID = 1L;

        public OnDragStopAjaxBehavior(IJQueryAjaxAware source) {
            super(source);
        }

        @Override
        protected CallbackParameter[] getCallbackParameters() {
            return new CallbackParameter[] { CallbackParameter.context("e"), // lf
                    CallbackParameter.resolved("top", "e.sender.hintOffset.top | 0"), // cast to int, no rounding
                    CallbackParameter.resolved("left", "e.sender.hintOffset.left | 0") // cast to int, no rounding
            };
        }

        @Override
        public CharSequence getCallbackFunctionBody(CallbackParameter... parameters) {
            String statement = "this.element.removeClass('" + CSS_HIDE + "');";
            return statement + super.getCallbackFunctionBody(parameters);
        }

        @Override
        protected JQueryEvent newEvent() {
            return new DragStopEvent();
        }
    }

    /**
     * Provides a {@link JQueryAjaxBehavior} that aims to be wired to the 'dragcancel' event
     */
    protected static class OnDragCancelAjaxBehavior extends JQueryAjaxBehavior {
        private static final long serialVersionUID = 1L;

        public OnDragCancelAjaxBehavior(IJQueryAjaxAware source) {
            super(source);
        }

        @Override
        protected CallbackParameter[] getCallbackParameters() {
            return new CallbackParameter[] { CallbackParameter.context("e"), // lf
                    CallbackParameter.resolved("top", "e.sender.hintOffset.top | 0"), // cast to int, no rounding
                    CallbackParameter.resolved("left", "e.sender.hintOffset.left | 0") // cast to int, no rounding
            };
        }

        @Override
        public CharSequence getCallbackFunctionBody(CallbackParameter... parameters) {
            String statement = "this.element.removeClass('" + CSS_HIDE + "');";
            return statement + super.getCallbackFunctionBody(parameters);
        }

        @Override
        protected JQueryEvent newEvent() {
            return new DragCancelEvent();
        }
    }

    // Event objects //

    /**
     * Provides a base class for {@link DraggableBehavior} event objects
     */
    protected static class DraggableEvent extends JQueryEvent {
        private final int top;
        private final int left;

        /**
         * Constructor.
         */
        public DraggableEvent() {
            this.top = RequestCycleUtils.getQueryParameterValue("top").toInt(-1);
            this.left = RequestCycleUtils.getQueryParameterValue("left").toInt(-1);
        }

        /**
         * Gets the position's top value
         *
         * @return the position's top value
         */
        public int getTop() {
            return this.top;
        }

        /**
         * Gets the position's left value
         *
         * @return the position's left value
         */
        public int getLeft() {
            return this.left;
        }
    }

    /**
     * Provides an event object that will be broadcasted by the {@link OnDragStartAjaxBehavior} callback
     */
    protected static class DragStartEvent extends DraggableEvent {
    }

    /**
     * Provides an event object that will be broadcasted by the {@link OnDragStopAjaxBehavior} callback
     */
    protected static class DragStopEvent extends DraggableEvent {
    }

    /**
     * Provides an event object that will be broadcasted by the {@link OnDragCancelAjaxBehavior} callback
     */
    protected static class DragCancelEvent extends DraggableEvent {
    }
}