de.eckhartarnold.client.TiledLayout.java Source code

Introduction

Here is the source code for de.eckhartarnold.client.TiledLayout.java

Source

/*
 * Copyright 2008 Eckhart Arnold (eckhart_arnold@hotmail.com).
 * 
 * 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.eckhartarnold.client;

// import com.google.gwt.core.client.GWT;
import com.google.gwt.user.client.ui.CellPanel;
import com.google.gwt.user.client.ui.HasHorizontalAlignment;
import com.google.gwt.user.client.ui.HasVerticalAlignment;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * Defines a "tiled" layout.
 * 
 * <p>A tiled layout consists
 * of three blocks, namely, the image panel ("I"), the control panel ("P")
 * and the caption ("C"), of which the image panel is obligatory while the
 * other two are optional. These three blocks can be arranged
 * horizontally and vertically in an almost arbitrary manner, with possible
 * horizontal delimiting lines (html "<hr />" tags) in between. However,
 * layouts where the image panel is arranged together with another element
 * horizontally may not work very well. But putting the control panel next to
 * the caption on top and the image panel below for example works quite well.
 *
 * @author ecki
 *
 */
public class TiledLayout extends FullScreenLayout {

    protected CellPanel panel;

    /**
     * Creates a tiled layout. The configuration string indicates the 
     * arrangement of the components "image" (represented by 'I'), 
     * "control panel" (represented by 'P') and "caption" (represented by 
     * 'C') and optional horizontal lines (represented by "-"). 
     * Components bracketed in squared brackets are arranged horizontally.
     * Without squared brackets components are arranged vertically.
     * Example: "[CP]-I" means that the caption and control panel are on top
     * and the control panel is placed to the right of the caption. Below
     * follows a horizontal separator and than the image panel.
     *  
     * @param collection     the information about the image collection
     * @param configuration  the configuration string.
     */
    public TiledLayout(ImageCollectionInfo collection, String configuration) {
        super(collection, configuration);
        panel = new VerticalPanel();
        panel.setStyleName("tiled");
        createTiles(panel, collection, configuration, 0);
    }

    /**
     * Creates a tiled layout with the configuration: "[CP]I".
     * 
     * @param collection  the information about the image collection
     */
    public TiledLayout(ImageCollectionInfo collection) {
        this(collection, "C-I-P");
    }

    /* (non-Javadoc)
     * @see de.eckhartarnold.client.Layout#getRootWidget()
     */
    @Override
    public Widget getRootWidget() {
        return panel;
    }

    @Override
    protected void initOverlayWidgets(ImageCollectionInfo info) {
    }

    private int createTiles(CellPanel parent, ImageCollectionInfo info, String config, int i) {
        while (i < config.length()) {
            switch (config.charAt(i)) {
            case ('C'): {
                parent.add(caption);
                caption.addStyleDependentName("tiled");
                parent.setCellVerticalAlignment(caption, HasVerticalAlignment.ALIGN_MIDDLE);
                parent.setCellHorizontalAlignment(caption, HasHorizontalAlignment.ALIGN_CENTER);
                parent.setCellWidth(caption, "100%");
                break;
            }
            case ('O'): {
                overlay = new CaptionOverlay(caption, imagePanel, slideshow,
                        info.getInfo().get(CaptionOverlay.KEY_CAPTION_POSITION));
            }
            case ('I'): {
                parent.add(imagePanel);
                parent.setCellVerticalAlignment(imagePanel, HasVerticalAlignment.ALIGN_MIDDLE);
                parent.setCellHorizontalAlignment(imagePanel, HasHorizontalAlignment.ALIGN_CENTER);
                parent.setCellWidth(imagePanel, "100%");
                parent.setCellHeight(imagePanel, "100%");
                break;
            }
            case ('P'):
            case ('F'): {
                assert control instanceof Widget;
                parent.add((Widget) control);
                ((Widget) control).addStyleDependentName("tiled");
                parent.setCellVerticalAlignment(((Widget) control), HasVerticalAlignment.ALIGN_MIDDLE);
                if (parent instanceof HorizontalPanel && parent.getWidgetCount() == 1) {
                    parent.setCellHorizontalAlignment(((Widget) control), HasHorizontalAlignment.ALIGN_RIGHT);
                } else {
                    parent.setCellHorizontalAlignment(((Widget) control), HasHorizontalAlignment.ALIGN_CENTER);
                }
                break;
            }
            case ('-'): {
                HTML horizLine = new HTML("<hr class=\"tiledSeparator\" />");
                panel.add(horizLine);
                break;
            }
            case (']'): {
                return i;
            }
            case ('['): {
                CellPanel panel;
                if (parent instanceof VerticalPanel) {
                    panel = new HorizontalPanel();
                    panel.setStyleName("tiled");
                } else {
                    panel = new VerticalPanel();
                    panel.setStyleName("tiled");
                }
                i = createTiles(panel, info, config, i + 1);
                parent.add(panel);
                break;
            }
            default:
                assert false : "Illegal token '" + config.charAt(i) + "' in config string";
            }
            i++;
        }
        return i;
    }

}