src/main/java/com/gitblit/wicket/pages/ImageDiffHandler.java - gitblit - Git at Google

 /*
  * Copyright 2014 Tom <tw201207@gmail.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 com.gitblit.wicket.pages;

 import java.nio.charset.StandardCharsets;
 import java.util.List;

 import org.apache.wicket.protocol.http.WebApplication;
 import org.apache.wicket.protocol.http.WicketURLEncoder;
 import org.eclipse.jgit.diff.DiffEntry;
 import org.eclipse.jgit.diff.DiffEntry.Side;
 import org.jsoup.nodes.Element;

 import com.gitblit.servlet.RawServlet;
 import com.gitblit.utils.DiffUtils;
 import com.gitblit.utils.HtmlBuilder;

 /**
  * A {@link DiffUtils.BinaryDiffHandler BinaryDiffHandler} for images.
  *
  * @author Tom <tw201207@gmail.com>
  */
 public class ImageDiffHandler implements DiffUtils.BinaryDiffHandler {

 	private final String oldCommitId;
 	private final String newCommitId;
 	private final String repositoryName;
 	private final BasePage page;
 	private final List<String> imageExtensions;

 	private int imgDiffCount = 0;

 	public ImageDiffHandler(final BasePage page, final String repositoryName, final String oldCommitId, final String newCommitId,
 			final List<String> imageExtensions) {
 		this.page = page;
 		this.repositoryName = repositoryName;
 		this.oldCommitId = oldCommitId;
 		this.newCommitId = newCommitId;
 		this.imageExtensions = imageExtensions;
 	}

 	/** {@inheritDoc} */
 	@Override
 	public String renderBinaryDiff(DiffEntry diffEntry) {
 		switch (diffEntry.getChangeType()) {
 		case MODIFY:
 		case RENAME:
 		case COPY:
 			// TODO: for very small images such as icons, the slider doesn't really help. Two possible
 			// approaches: either upscale them for display (may show blurry upscaled images), or show
 			// them side by side (may still be too small to really make out the differences).
 			String oldUrl = getImageUrl(diffEntry, Side.OLD);
 			String newUrl = getImageUrl(diffEntry, Side.NEW);
 			if (oldUrl != null && newUrl != null) {
 				imgDiffCount++;
 				String id = "imgdiff" + imgDiffCount;
 				HtmlBuilder builder = new HtmlBuilder("div");
 				Element wrapper = builder.root().attr("class", "imgdiff-container").attr("id", "imgdiff-" + id);
 				Element container = wrapper.appendElement("div").attr("class", "imgdiff-ovr-slider").appendElement("div").attr("class", "imgdiff");
 				Element old = container.appendElement("div").attr("class", "imgdiff-left");
 				// style='max-width:640px;' is necessary for ensuring that the browser limits large images
 				// to some reasonable width, and to override the "img { max-width: 100%; }" from bootstrap.css,
 				// which would scale the left image to the width of its resizeable container, which isn't what
 				// we want here. Note that the max-width must be defined directly as inline style on the element,
 				// otherwise browsers ignore it if the image is larger, and we end up with an image display that
 				// is too wide.
 				// XXX: Maybe add a max-height, too, to limit portrait-oriented images to some reasonable height?
 				// (Like a 300x10000px image...)
 				old.appendElement("img").attr("class", "imgdiff-old").attr("id", id).attr("style", "max-width:640px;").attr("src", oldUrl);
 				container.appendElement("img").attr("class", "imgdiff").attr("style", "max-width:640px;").attr("src", newUrl);
 				wrapper.appendElement("br");
 				Element controls = wrapper.appendElement("div");
 				// Opacity slider
 				controls.appendElement("div").attr("class", "imgdiff-opa-container").appendElement("a").attr("class", "imgdiff-opa-slider")
 						.attr("href", "#").attr("title", page.getString("gb.opacityAdjust"));
 				// Blink comparator: find Pluto!
 				controls.appendElement("a").attr("class", "imgdiff-link imgdiff-blink").attr("href", "#")
 						.attr("title", page.getString("gb.blinkComparator"))
 						.appendElement("img").attr("src", getStaticResourceUrl("blink32.png")).attr("width", "20");
 				// Pixel subtraction, initially not displayed, will be shown by imgdiff.js depending on feature test.
 				// (Uses CSS mix-blend-mode, which isn't supported on all browsers yet).
 				controls.appendElement("a").attr("class", "imgdiff-link imgdiff-subtract").attr("href", "#")
 						.attr("title", page.getString("gb.imgdiffSubtract")).attr("style", "display:none;")
 						.appendElement("img").attr("src", getStaticResourceUrl("sub32.png")).attr("width", "20");
 				return builder.toString();
 			}
 			break;
 		case ADD:
 			String url = getImageUrl(diffEntry, Side.NEW);
 			if (url != null) {
 				return new HtmlBuilder("img").root().attr("class", "diff-img").attr("src", url).toString();
 			}
 			break;
 		default:
 			break;
 		}
 		return null;
 	}

 	/** Returns the number of image diffs generated so far by this {@link ImageDiffHandler}. */
 	public int getImgDiffCount() {
 		return imgDiffCount;
 	}

 	/**
 	 * Constructs a URL that will fetch the designated resource in the git repository. The returned string will
 	 * contain the URL fully URL-escaped, but note that it may still contain unescaped ampersands, so the result
 	 * must still be run through HTML escaping if it is to be used in HTML.
 	 *
 	 * @return the URL to the image, if the given {@link DiffEntry} and {@link Side} refers to an image, or {@code null} otherwise.
 	 */
 	protected String getImageUrl(DiffEntry entry, Side side) {
 		String path = entry.getPath(side);
 		int i = path.lastIndexOf('.');
 		if (i > 0) {
 			String extension = path.substring(i + 1);
 			for (String ext : imageExtensions) {
 				if (ext.equalsIgnoreCase(extension)) {
 					String commitId = Side.NEW.equals(side) ? newCommitId : oldCommitId;
 					if (commitId != null) {
 						return RawServlet.asLink(page.getContextUrl(), urlencode(repositoryName), commitId, urlencode(path));
 					} else {
 						return null;
 					}
 				}
 			}
 		}
 		return null;
 	}

 	/**
 	 * Returns a URL that will fetch the designated static resource from within GitBlit.
 	 */
 	protected String getStaticResourceUrl(String contextRelativePath) {
 		return WebApplication.get().getRequestCycleProcessor().getRequestCodingStrategy().rewriteStaticRelativeUrl(contextRelativePath);
 	}

 	/**
 	 * Encode a URL component of a {@link RawServlet} URL in the special way that the servlet expects it. Note that
 	 * the %-encoding used does not encode '&amp;' or '&lt;'. Slashes are not encoded in the result.
 	 *
 	 * @param component
 	 *            to encode using %-encoding
 	 * @return the encoded component
 	 */
 	protected String urlencode(final String component) {
 		// RawServlet handles slashes itself. Note that only the PATH_INSTANCE fits the bill here: it encodes
 		// spaces as %20, and we just have to correct for encoded slashes. Java's standard URLEncoder would
 		// encode spaces as '+', and I don't know what effects that would have on other parts of GitBlit. It
 		// would also be wrong for path components (but fine for a query part), so we'd have to correct it, too.
 		//
 		// Actually, this should be done in RawServlet.asLink(). As it is now, this may be incorrect if that
 		// operation ever uses query parameters instead of paths, or if it is fixed to urlencode its path
 		// components. But I don't want to touch that static method in RawServlet.
 		return WicketURLEncoder.PATH_INSTANCE.encode(component, StandardCharsets.UTF_8.name()).replaceAll("%2[fF]", "/");
 	}
 }
	/*
	* Copyright 2014 Tom <tw201207@gmail.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 com.gitblit.wicket.pages;

	import java.nio.charset.StandardCharsets;
	import java.util.List;

	import org.apache.wicket.protocol.http.WebApplication;
	import org.apache.wicket.protocol.http.WicketURLEncoder;
	import org.eclipse.jgit.diff.DiffEntry;
	import org.eclipse.jgit.diff.DiffEntry.Side;
	import org.jsoup.nodes.Element;

	import com.gitblit.servlet.RawServlet;
	import com.gitblit.utils.DiffUtils;
	import com.gitblit.utils.HtmlBuilder;

	/**
	* A {@link DiffUtils.BinaryDiffHandler BinaryDiffHandler} for images.
	*
	* @author Tom <tw201207@gmail.com>
	*/
	public class ImageDiffHandler implements DiffUtils.BinaryDiffHandler {

	private final String oldCommitId;
	private final String newCommitId;
	private final String repositoryName;
	private final BasePage page;
	private final List<String> imageExtensions;

	private int imgDiffCount = 0;

	public ImageDiffHandler(final BasePage page, final String repositoryName, final String oldCommitId, final String newCommitId,
	final List<String> imageExtensions) {
	this.page = page;
	this.repositoryName = repositoryName;
	this.oldCommitId = oldCommitId;
	this.newCommitId = newCommitId;
	this.imageExtensions = imageExtensions;
	}

	/** {@inheritDoc} */
	@Override
	public String renderBinaryDiff(DiffEntry diffEntry) {
	switch (diffEntry.getChangeType()) {
	case MODIFY:
	case RENAME:
	case COPY:
	// TODO: for very small images such as icons, the slider doesn't really help. Two possible
	// approaches: either upscale them for display (may show blurry upscaled images), or show
	// them side by side (may still be too small to really make out the differences).
	String oldUrl = getImageUrl(diffEntry, Side.OLD);
	String newUrl = getImageUrl(diffEntry, Side.NEW);
	if (oldUrl != null && newUrl != null) {
	imgDiffCount++;
	String id = "imgdiff" + imgDiffCount;
	HtmlBuilder builder = new HtmlBuilder("div");
	Element wrapper = builder.root().attr("class", "imgdiff-container").attr("id", "imgdiff-" + id);
	Element container = wrapper.appendElement("div").attr("class", "imgdiff-ovr-slider").appendElement("div").attr("class", "imgdiff");
	Element old = container.appendElement("div").attr("class", "imgdiff-left");
	// style='max-width:640px;' is necessary for ensuring that the browser limits large images
	// to some reasonable width, and to override the "img { max-width: 100%; }" from bootstrap.css,
	// which would scale the left image to the width of its resizeable container, which isn't what
	// we want here. Note that the max-width must be defined directly as inline style on the element,
	// otherwise browsers ignore it if the image is larger, and we end up with an image display that
	// is too wide.
	// XXX: Maybe add a max-height, too, to limit portrait-oriented images to some reasonable height?
	// (Like a 300x10000px image...)
	old.appendElement("img").attr("class", "imgdiff-old").attr("id", id).attr("style", "max-width:640px;").attr("src", oldUrl);
	container.appendElement("img").attr("class", "imgdiff").attr("style", "max-width:640px;").attr("src", newUrl);
	wrapper.appendElement("br");
	Element controls = wrapper.appendElement("div");
	// Opacity slider
	controls.appendElement("div").attr("class", "imgdiff-opa-container").appendElement("a").attr("class", "imgdiff-opa-slider")
	.attr("href", "#").attr("title", page.getString("gb.opacityAdjust"));
	// Blink comparator: find Pluto!
	controls.appendElement("a").attr("class", "imgdiff-link imgdiff-blink").attr("href", "#")
	.attr("title", page.getString("gb.blinkComparator"))
	.appendElement("img").attr("src", getStaticResourceUrl("blink32.png")).attr("width", "20");
	// Pixel subtraction, initially not displayed, will be shown by imgdiff.js depending on feature test.
	// (Uses CSS mix-blend-mode, which isn't supported on all browsers yet).
	controls.appendElement("a").attr("class", "imgdiff-link imgdiff-subtract").attr("href", "#")
	.attr("title", page.getString("gb.imgdiffSubtract")).attr("style", "display:none;")
	.appendElement("img").attr("src", getStaticResourceUrl("sub32.png")).attr("width", "20");
	return builder.toString();
	}
	break;
	case ADD:
	String url = getImageUrl(diffEntry, Side.NEW);
	if (url != null) {
	return new HtmlBuilder("img").root().attr("class", "diff-img").attr("src", url).toString();
	}
	break;
	default:
	break;
	}
	return null;
	}

	/** Returns the number of image diffs generated so far by this {@link ImageDiffHandler}. */
	public int getImgDiffCount() {
	return imgDiffCount;
	}

	/**
	* Constructs a URL that will fetch the designated resource in the git repository. The returned string will
	* contain the URL fully URL-escaped, but note that it may still contain unescaped ampersands, so the result
	* must still be run through HTML escaping if it is to be used in HTML.
	*
	* @return the URL to the image, if the given {@link DiffEntry} and {@link Side} refers to an image, or {@code null} otherwise.
	*/
	protected String getImageUrl(DiffEntry entry, Side side) {
	String path = entry.getPath(side);
	int i = path.lastIndexOf('.');
	if (i > 0) {
	String extension = path.substring(i + 1);
	for (String ext : imageExtensions) {
	if (ext.equalsIgnoreCase(extension)) {
	String commitId = Side.NEW.equals(side) ? newCommitId : oldCommitId;
	if (commitId != null) {
	return RawServlet.asLink(page.getContextUrl(), urlencode(repositoryName), commitId, urlencode(path));
	} else {
	return null;
	}
	}
	}
	}
	return null;
	}

	/**
	* Returns a URL that will fetch the designated static resource from within GitBlit.
	*/
	protected String getStaticResourceUrl(String contextRelativePath) {
	return WebApplication.get().getRequestCycleProcessor().getRequestCodingStrategy().rewriteStaticRelativeUrl(contextRelativePath);
	}

	/**
	* Encode a URL component of a {@link RawServlet} URL in the special way that the servlet expects it. Note that
	* the %-encoding used does not encode '&' or '<'. Slashes are not encoded in the result.
	*
	* @param component
	* to encode using %-encoding
	* @return the encoded component
	*/
	protected String urlencode(final String component) {
	// RawServlet handles slashes itself. Note that only the PATH_INSTANCE fits the bill here: it encodes
	// spaces as %20, and we just have to correct for encoded slashes. Java's standard URLEncoder would
	// encode spaces as '+', and I don't know what effects that would have on other parts of GitBlit. It
	// would also be wrong for path components (but fine for a query part), so we'd have to correct it, too.
	//
	// Actually, this should be done in RawServlet.asLink(). As it is now, this may be incorrect if that
	// operation ever uses query parameters instead of paths, or if it is fixed to urlencode its path
	// components. But I don't want to touch that static method in RawServlet.
	return WicketURLEncoder.PATH_INSTANCE.encode(component, StandardCharsets.UTF_8.name()).replaceAll("%2[fF]", "/");
	}
	}