io.wcm.handler.media.markup.MediaMarkupBuilderUtil.java Source code

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/*
 * #%L
 * wcm.io
 * %%
 * Copyright (C) 2014 wcm.io
 * %%
 * 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.
 * #L%
 */
package io.wcm.handler.media.markup;

import io.wcm.handler.commons.dom.HtmlElement;
import io.wcm.handler.media.Dimension;
import io.wcm.handler.media.Media;
import io.wcm.handler.media.MediaArgs;
import io.wcm.handler.media.MediaNameConstants;
import io.wcm.handler.media.MediaRequest;
import io.wcm.handler.media.format.MediaFormat;
import io.wcm.handler.media.spi.MediaMarkupBuilder;
import io.wcm.sling.commons.request.RequestParam;

import org.apache.commons.lang3.StringUtils;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.resource.Resource;
import org.apache.sling.api.resource.ValueMap;
import org.osgi.annotation.versioning.ProviderType;

import com.day.cq.commons.DiffInfo;
import com.day.cq.commons.DiffService;
import com.day.cq.wcm.api.Page;
import com.day.cq.wcm.api.PageManager;
import com.day.cq.wcm.api.components.ComponentContext;

/**
 * Helper methods for {@link MediaMarkupBuilder} implementations.
 */
@ProviderType
public final class MediaMarkupBuilderUtil {

    private MediaMarkupBuilderUtil() {
        // static methods only
    }

    /**
     * Adds CSS classes that denote the changes to the media element when compared to a different version.
     * If no diff has been requested by the WCM UI, there won't be any changes to the element.
     * @param mediaElement Element to be decorated
     * @param resource Resource pointing to JCR node
     * @param refProperty Name of property for media library item reference. If null, default name is used.
     * @param request Servlet request
     */
    public static void addDiffDecoration(HtmlElement<?> mediaElement, Resource resource, String refProperty,
            SlingHttpServletRequest request) {

        PageManager pageManager = request.getResourceResolver().adaptTo(PageManager.class);
        Page currentPage = pageManager.getContainingPage(request.getResource());
        Page resourcePage = pageManager.getContainingPage(resource);

        String versionLabel = RequestParam.get(request, DiffService.REQUEST_PARAM_DIFF_TO);
        // Only try to diff when the resource is contained within the current page as the version number requested always
        // refers to the version history of the current page. So chances a resource on another page doesn't have a matching
        // version, and even if it has, it's comparing apples and oranges
        if (StringUtils.isNotEmpty(versionLabel) && currentPage != null && currentPage.equals(resourcePage)) {
            Resource versionedResource = DiffInfo.getVersionedResource(resource, versionLabel);
            if (versionedResource != null) {
                ValueMap currentProperties = resource.getValueMap();
                ValueMap oldProperties = versionedResource.getValueMap();

                String currentMediaRef = currentProperties.get(refProperty, String.class);
                String oldMediaRef = oldProperties.get(refProperty, String.class);
                if (!StringUtils.equals(currentMediaRef, oldMediaRef)) {
                    if (StringUtils.isEmpty(currentMediaRef)) {
                        mediaElement.addCssClass(MediaNameConstants.CSS_DIFF_REMOVED);
                    } else if (StringUtils.isEmpty(oldMediaRef)) {
                        mediaElement.addCssClass(MediaNameConstants.CSS_DIFF_ADDED);
                    } else {
                        mediaElement.addCssClass(MediaNameConstants.CSS_DIFF_UPDATED);
                    }
                } else {

                    // If the mediaRef itself hasn't changed, check the cropping coordinates
                    String currentMediaCrop = currentProperties.get(MediaNameConstants.PN_MEDIA_CROP, String.class);
                    String oldMediaCrop = oldProperties.get(MediaNameConstants.PN_MEDIA_CROP, String.class);
                    if (!StringUtils.equals(currentMediaCrop, oldMediaCrop)) {
                        mediaElement.addCssClass(MediaNameConstants.CSS_DIFF_UPDATED);
                    }

                    // we also could try to determine here whether it resolves to another rendition
                    // or if the timestamp of the rendition has been updated (which would indicate the the binary payload has been
                    // changed).
                    // This however, is out of scope for this feature right now
                }
            } else {
                // The resource didn't exist in the old version at all
                mediaElement.addCssClass(MediaNameConstants.CSS_DIFF_ADDED);
            }
        }
    }

    /**
     * Get dimension from first media format defined in media args. Fall back to dummy min. dimension if none specified.
     * @param media Media metadata
     * @return Dimension
     */
    public static Dimension getMediaformatDimension(Media media) {
        // Create dummy image element to be displayed in Edit mode as placeholder.
        MediaArgs mediaArgs = media.getMediaRequest().getMediaArgs();
        MediaFormat[] mediaFormats = mediaArgs.getMediaFormats();

        // detect width/height - either from media args, or from first media format
        long width = mediaArgs.getFixedWidth();
        long height = mediaArgs.getFixedHeight();
        if ((width == 0 || height == 0) && mediaFormats != null && mediaFormats.length > 0) {
            MediaFormat firstMediaFormat = mediaArgs.getMediaFormats()[0];
            Dimension dimension = firstMediaFormat.getMinDimension();
            if (dimension != null) {
                width = dimension.getWidth();
                height = dimension.getHeight();
            }
        }

        // fallback to min width/height
        if (width == 0) {
            width = MediaMarkupBuilder.DUMMY_MIN_DIMENSION;
        }
        if (height == 0) {
            height = MediaMarkupBuilder.DUMMY_MIN_DIMENSION;
        }

        return new Dimension(width, height);
    }

    /**
     * Implements check whether to apply drag&amp;drop support as described in {@link DragDropSupport}.
     * @param mediaRequest Media request
     * @param wcmComponentContext WCM component context
     * @return true if drag&amp;droup can be applied.
     */
    public static boolean canApplyDragDropSupport(MediaRequest mediaRequest, ComponentContext wcmComponentContext) {
        switch (mediaRequest.getMediaArgs().getDragDropSupport()) {
        case ALWAYS:
            return true;
        case NEVER:
            return false;
        case AUTO:
            String resourcePath = null;
            if (mediaRequest.getResource() != null) {
                resourcePath = mediaRequest.getResource().getPath();
            }
            String componentResourcePath = null;
            if (wcmComponentContext != null && wcmComponentContext.getResource() != null) {
                componentResourcePath = wcmComponentContext.getResource().getPath();
            }
            return resourcePath != null && StringUtils.equals(resourcePath, componentResourcePath);
        default:
            throw new IllegalArgumentException(
                    "Unsupported drag&drop support mode: " + mediaRequest.getMediaArgs().getDragDropSupport());
        }

    }

}