de.swm.commons.mobile.client.widgets.IndexedScrollPanel.java Source code

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Here is the source code for de.swm.commons.mobile.client.widgets.IndexedScrollPanel.java

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/*
 * Copyright 2011 SWM Services GmbH.
 * 
 * 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 de.swm.commons.mobile.client.widgets;

import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.user.client.ui.Label;
import de.swm.commons.mobile.client.SWMMobile;
import de.swm.commons.mobile.client.widgets.scroll.ScrollPanel;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * Indes scroll panel is a address book like widget that orders his entries alphabetically including a selection index
 * displayed on the right.
 * 
 */
public class IndexedScrollPanel extends HorizontalPanel {

    private static final double INNER_HEIGHT = 90.0;
    private static final double OUTER_HEIGHT = 100.0;
    private static final Set<Integer> usedIndexes = new HashSet<Integer>();

    private static final String[] letters = { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N",
            "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };

    private final ScrollPanel scroller;
    private final ListPanel list;

    /**
     * Default constructor.
     */
    public IndexedScrollPanel() {
        getElement().getStyle().setHeight(INNER_HEIGHT, Unit.PCT); // compensation for height of header panel
        scroller = new ScrollPanel();
        scroller.getElement().getStyle().setHeight(OUTER_HEIGHT, Unit.PCT);
        list = new ListPanel();
        createAlphabeticalIndex();
        scroller.add(list);
        add(scroller);
    }

    /**
     * Create the basic index structure,.
     */
    private void createAlphabeticalIndex() {
        for (int i = 0; i < letters.length; i++) {
            ListItem item = new ListItem();
            item.addStyleName(SWMMobile.getTheme().getMGWTCssBundle().getIndexPanelCss().indexHeaderListItem());
            item.add(new Label(letters[i]));
            item.setDisabled(true);
            list.add(item);
        }
    }

    /**
     * Adds the items to the pannel.
     * 
     * @param sectionIndex
     *            the selection index
     * @param items
     *            the items
     */
    public void setIndexedItems(int sectionIndex, List<ListItem> items) {
        if (!items.isEmpty()) {
            usedIndexes.add(sectionIndex);
        }
        int pos = findIndexedSectionPosition(sectionIndex);
        if (pos >= 0) {
            for (int j = items.size(); j > 0; j--) {
                list.insert(items.get(j - 1), (pos + 1));
            }
        }
    }

    /**
     * Reomoves the header of empty indexes.
     */
    public void removeEmptyIndexes() {
        final List<ListItem> listItemsToRemove = new ArrayList<ListItem>();

        ListPanel list = (ListPanel) scroller.getWidget();
        int sectionItem = 0;
        for (int i = 0; i < list.getWidgetCount(); i++) {
            ListItem item = list.getItem(i);
            if (item.getElement().getClassName()
                    .contains(SWMMobile.getTheme().getMGWTCssBundle().getIndexPanelCss().indexHeaderListItem())) {
                if (!usedIndexes.contains(sectionItem)) {
                    listItemsToRemove.add(item);
                }
                sectionItem++;
            }
        }

        for (ListItem listItem : listItemsToRemove) {
            list.remove(listItem);
        }
    }

    /**
     * Clears all entries.
     * 
     * @see de.swm.commons.mobile.client.base.PanelBase#clear()
     */
    @Override
    public void clear() {
        list.clear();
        usedIndexes.clear();
        createAlphabeticalIndex();
    }

    /**
     * Finds the screen position of an concrete index
     * 
     * @param sectionIndex
     *            the index
     * @return the screen position.
     */
    private int findIndexedSectionPosition(int sectionIndex) {
        ListPanel list = (ListPanel) scroller.getWidget();
        int s = 0;
        for (int i = 0; i < list.getWidgetCount(); i++) {
            ListItem item = list.getItem(i);
            if (item.getElement().getClassName()
                    .contains(SWMMobile.getTheme().getMGWTCssBundle().getIndexPanelCss().indexHeaderListItem())) {
                if (s == sectionIndex) {
                    return i;
                }
                s++;
            }
        }
        return -1;
    }
}