CategoriesList.java

/*******************************************************************************
 * Copyright (c) 2012-2017 Codenvy, S.A.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Codenvy, S.A. - initial API and implementation
 *******************************************************************************/
package org.eclipse.che.ide.ui.list;

import com.google.gwt.dom.client.Element;
import com.google.gwt.resources.client.ClientBundle;
import com.google.gwt.resources.client.CssResource;
import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.FlowPanel;

import org.vectomatic.dom.svg.ui.SVGResource;

import java.util.ArrayList;
import java.util.List;

/**
 * @author Evgen Vidolob
 * @author Vitaliy Guliy
 */
public class CategoriesList extends Composite {
    /** Defines the attribute used to indicate selection. */
    private static final String SELECTED_ATTRIBUTE = "SELECTED";
    private final Resources                 resources;
    private final SelectionManager          selectionManager;
    private       List<CategoryNodeElement> categoryNodeElements;

    private FlowPanel rootPanel;
    private FlowPanel scrollPanel;
    private FlowPanel lockPanel;

    private boolean enabled = true;

    public CategoriesList(Resources resources) {
        this.resources = resources;
        this.categoryNodeElements = new ArrayList<>();

        rootPanel = new FlowPanel();
        rootPanel.setStyleName(resources.defaultCategoriesListCss().rootPanel());
        initWidget(rootPanel);

        scrollPanel = new FlowPanel();
        scrollPanel.setStyleName(resources.defaultCategoriesListCss().scrollPanel());
        rootPanel.add(scrollPanel);

        lockPanel = new FlowPanel();
        lockPanel.setStyleName(resources.defaultCategoriesListCss().lockPanel());
        lockPanel.setVisible(false);
        rootPanel.add(lockPanel);

        selectionManager = new SelectionManager();
    }

    /**
     * Refreshes list of items.
     * <p/>
     * <p>This method tries to keep selection.
     *
     * @param categories
     *         the categories
     * @param renderChildren
     *         if is true - child node will be expanded, otherwise only root node.
     */
    public void render(List<Category<?>> categories, boolean renderChildren) {
        this.categoryNodeElements = new ArrayList<>();
        for (Category category : categories) {
            CategoryNodeElement categoryNodeElement = new CategoryNodeElement(category, renderChildren, selectionManager, resources);
            categoryNodeElements.add(categoryNodeElement);
            scrollPanel.add(categoryNodeElement);
        }
    }

    /**
     * Select object in the list.
     *
     * @param element
     * @return
     */
    public boolean selectElement(Object element) {
        if (categoryNodeElements == null || categoryNodeElements.isEmpty()) {
            return false;
        }

        for (CategoryNodeElement category : categoryNodeElements) {
            if (category.containsItem(element)) {
                category.selectItem(element);
                return true;
            }
        }

        return false;
    }

    /**
     * Clears list of items.
     */
    public void clear() {
        scrollPanel.clear();
        categoryNodeElements = null;
    }

    /**
     * Enables ot disables this widget.
     *
     * @param enabled
     *         enabled state
     */
    public void setEnabled(boolean enabled) {
        if (enabled) {
            lockPanel.setVisible(false);
            scrollPanel.getElement().getStyle().clearProperty("opacity");
        } else {
            lockPanel.setVisible(true);
            scrollPanel.getElement().getStyle().setProperty("opacity", "0.5");
        }

        this.enabled = enabled;
    }

    class SelectionManager {

        private Element selectedItem;

        public void selectItem(Element item) {
            if (selectedItem != null) {
                selectedItem.removeAttribute(SELECTED_ATTRIBUTE);
            }
            selectedItem = item;
            selectedItem.setAttribute(SELECTED_ATTRIBUTE, SELECTED_ATTRIBUTE);
        }
    }

    /** Item style selectors for a categories list item. */
    public interface Css extends CssResource {

        String rootPanel();

        String scrollPanel();

        String lockPanel();


        String categoryItem();

        String category();

        String categoryLabel();

        String expandControl();

        String categoryHeader();

        String expandedImage();

        String itemContainer();

        String headerText();
    }

    public interface Resources extends ClientBundle {
        @Source({"CategoriesList.css", "org/eclipse/che/ide/ui/constants.css", "org/eclipse/che/ide/api/ui/style.css"})
        Css defaultCategoriesListCss();

        @Source("arrowExpansionIcon.svg")
        SVGResource arrowExpansionImage();
    }
}