name.martingeisse.wicket.component.tree.TreeAjaxBehavior.java Source code

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Here is the source code for name.martingeisse.wicket.component.tree.TreeAjaxBehavior.java

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/**
 * Copyright (c) 2010 Martin Geisse
 *
 * This file is distributed under the terms of the MIT license.
 */

package name.martingeisse.wicket.component.tree;

import java.util.ArrayList;
import java.util.List;
import name.martingeisse.common.javascript.JavascriptAssemblerUtil;
import name.martingeisse.common.terms.CommandVerb;
import name.martingeisse.common.util.GenericTypeUtil;
import name.martingeisse.wicket.component.contextmenu.ContextMenu;
import name.martingeisse.wicket.component.contextmenu.IContextMenuCallbackBuilder;
import name.martingeisse.wicket.component.tree.JsTree.Item;
import name.martingeisse.wicket.javascript.IJavascriptInteractionInterceptor;
import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;
import org.apache.wicket.Component;
import org.apache.wicket.Page;
import org.apache.wicket.ajax.AbstractDefaultAjaxBehavior;
import org.apache.wicket.ajax.AjaxRequestTarget;
import org.apache.wicket.ajax.attributes.CallbackParameter;
import org.apache.wicket.request.IRequestParameters;
import org.apache.wicket.request.cycle.RequestCycle;
import org.json.simple.JSONValue;

/**
 * Handles AJAX requests for a JsTree.
 * 
 * @param <T> the tree node type
 */
class TreeAjaxBehavior<T> extends AbstractDefaultAjaxBehavior implements IContextMenuCallbackBuilder {

    /**
     * the logger
     */
    @SuppressWarnings("unused")
    private static Logger logger = Logger.getLogger(TreeAjaxBehavior.class);

    /**
     * the CONTEXT_MENU_INTERACTION_PREFIX
     */
    private static final String CONTEXT_MENU_INTERACTION_PREFIX = "contextMenu.";

    /**
     * the COMMAND_VERB_INTERACTION_PREFIX
     */
    private static final String COMMAND_VERB_INTERACTION_PREFIX = "commandVerb.";

    /**
     * the tree
     */
    private final JsTree<T> tree;

    /**
     * Constructor.
     * @param tree the tree
     */
    TreeAjaxBehavior(final JsTree<T> tree) {
        this.tree = tree;
    }

    /* (non-Javadoc)
     * @see org.apache.wicket.behavior.Behavior#onConfigure(org.apache.wicket.Component)
     */
    @Override
    public void onConfigure(Component component) {
        super.onConfigure(component);
        tree.getContextMenu().onConfigure(component);
    };

    /**
     * Returns a Javascript expression that specifies the AJAX callback function.
     */
    String getCallbackSpecifier() {
        final CallbackParameter[] parameters = new CallbackParameter[] { CallbackParameter.explicit("interaction"),
                CallbackParameter.explicit("selectedNodes"), CallbackParameter.explicit("data"), };
        return getCallbackFunction(parameters).toString().replace("\n", " ");
    }

    /* (non-Javadoc)
     * @see org.apache.wicket.ajax.AbstractDefaultAjaxBehavior#respond(org.apache.wicket.ajax.AjaxRequestTarget)
     */
    @Override
    protected void respond(final AjaxRequestTarget target) {
        final RequestCycle requestCycle = RequestCycle.get();
        final IRequestParameters parameters = requestCycle.getRequest().getRequestParameters();
        final String interaction = parameters.getParameterValue("interaction").toString();
        final String selectedNodeIndices = parameters.getParameterValue("selectedNodes").toString();
        if (interaction != null && selectedNodeIndices != null) {
            final List<T> selectedNodes = lookupSelectedNodes(selectedNodeIndices);
            final Object data = getJsonParameter(parameters, "data", "null");
            if (interaction.startsWith(CONTEXT_MENU_INTERACTION_PREFIX)) {
                final ContextMenu<List<T>> contextMenu = tree.getContextMenu();
                if (contextMenu != null) {
                    final String menuItemKey = interaction.substring(CONTEXT_MENU_INTERACTION_PREFIX.length());
                    contextMenu.notifySelected(menuItemKey, selectedNodes, data);
                }
            } else if (interaction.startsWith(COMMAND_VERB_INTERACTION_PREFIX)) {
                String commandVerbCanonicalId = interaction.substring(COMMAND_VERB_INTERACTION_PREFIX.length());
                CommandVerb commandVerb = CommandVerb.fromCanonicalIdentifierSafe(commandVerbCanonicalId);
                if (commandVerb != null) {
                    tree.onCommandVerb(commandVerb, selectedNodes, data);
                }
            } else {
                tree.onInteraction(interaction, selectedNodes, data);
                if (interaction.equals("dblclick")) {
                    tree.onDoubleClick(selectedNodes, data);
                }
            }
        }
    }

    /**
     * 
     */
    private static Object getJsonParameter(final IRequestParameters parameters, final String name,
            final String encodedDefaultValue) {
        String encodedValue = parameters.getParameterValue(name).toString();
        if (encodedValue == null) {
            encodedValue = encodedDefaultValue;
        }
        return JSONValue.parse(encodedValue);
    }

    /**
     * Converts a list of node indices from JSON to the internal node type T.
     * @param specifier specifier the node index list
     * @return the internal nodes
     */
    protected List<T> lookupSelectedNodes(final String specifier) {
        final List<T> result = new ArrayList<T>();
        if (specifier.isEmpty()) {
            return result;
        }
        for (final String nodeSpec : StringUtils.split(specifier, ':')) {
            try {
                final Item<T> item = GenericTypeUtil.unsafeCast((Item<?>) tree.get(nodeSpec));
                result.add(item.getModelObject());
            } catch (final Exception e) {
                logger.debug("could not parse JsTree item specifier: " + specifier, e);
            }
        }
        return result;
    }

    /* (non-Javadoc)
     * @see name.martingeisse.webide.workbench.components.contextmenu.IContextMenuCallbackBuilder#buildContextMenuCallback(java.lang.StringBuilder)
     */
    @Override
    public void buildContextMenuCallback(final StringBuilder builder) {
        builder.append("var interaction = '" + CONTEXT_MENU_INTERACTION_PREFIX + "' + key;");
        builder.append("\t$('#").append(tree.getMarkupId()).append("').jstreeInteract(interaction, data);\n");
    }

    /* (non-Javadoc)
     * @see name.martingeisse.wicket.component.contextmenu.IContextMenuCallbackBuilder#buildContextMenuCallback(java.lang.StringBuilder, name.martingeisse.common.terms.CommandVerb)
     */
    @Override
    public void buildContextMenuCallback(final StringBuilder builder, final CommandVerb commandVerb) {
        buildCommandVerbInteraction(builder, commandVerb);
    }

    /**
     * Builds a Javascript fragment that sends a command verb to the tree component, respecting the
     * interceptor for that verb.
     */
    void buildCommandVerbInteraction(final StringBuilder builder, final CommandVerb commandVerb) {
        String interactionId = (COMMAND_VERB_INTERACTION_PREFIX + commandVerb.getCanonicalIdentifier());
        IJavascriptInteractionInterceptor<?> interceptor = tree.getInterceptor(commandVerb);
        if (interceptor != null) {
            builder.append("function onInterceptorPassed(data) {\n");
        } else {
            builder.append("var data = null;\n");
        }
        builder.append("var interaction = '"
                + JavascriptAssemblerUtil.escapeStringLiteralSpecialCharacters(interactionId) + "';\n");
        builder.append("\t$('#").append(tree.getMarkupId()).append("').jstreeInteract(interaction, data);\n");
        if (interceptor != null) {
            builder.append("}\n");
            builder.append("var interceptor = ");
            interceptor.printInterceptorFunction(builder);
            builder.append(";");
            builder.append("interceptor(onInterceptorPassed);\n");
        }
    }

    /* (non-Javadoc)
     * @see name.martingeisse.wicket.component.contextmenu.IContextMenuCallbackBuilder#getPage()
     */
    @Override
    public Page getPage() {
        return getComponent().getPage();
    }

}