Image diffs

Ticket 88: https://dev.gitblit.com/tickets/gitblit.git/88

Based on Lea Verou's pure CSS slider:
http://lea.verou.me/2014/07/image-comparison-slider-with-pure-css/

* Add a callback interface, pass it through DiffUtils to the
  GitBlitDiffFormatter. Is needed because the rendering needs access
  to the repositoryName and other things that are known only at higher
  levels.
  
* New class ImageDiffHandler responsible for rendering an image diff.
  Called for all binary diffs, doesn't do anything if it's not an
  image. HTML is generated via JSoup: no worries about forgetting to
  close a tag, not about HTML escaping, nor about XSS.
  
* The 3 diff pages set up such an ImageDIffHandler and pass it along.

* CSS changes: from Lea Verou, with some minor improvements.

I think in the long run there'll be no way around rewriting the
HTML diff formatter from scratch, not using the standard JGit
DiffFormatter at all.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/main/java/com/gitblit/wicket/pages/CommitDiffPage.java b/src/main/java/com/gitblit/wicket/pages/CommitDiffPage.java
index 34ff5a29..77d5ccf3 100644
--- a/src/main/java/com/gitblit/wicket/pages/CommitDiffPage.java
+++ b/src/main/java/com/gitblit/wicket/pages/CommitDiffPage.java
@@ -31,6 +31,7 @@ import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
 
 import com.gitblit.Constants;
+import com.gitblit.Keys;
 import com.gitblit.models.GitNote;
 import com.gitblit.models.PathModel.PathChangeModel;
 import com.gitblit.models.SubmoduleModel;
@@ -59,8 +60,6 @@ public class CommitDiffPage extends RepositoryPage {
 
 		RevCommit commit = getCommit();
 
-		final DiffOutput diff = DiffUtils.getCommitDiff(r, commit, DiffOutputType.HTML);
-
 		List<String> parents = new ArrayList<String>();
 		if (commit.getParentCount() > 0) {
 			for (RevCommit parent : commit.getParents()) {
@@ -82,6 +81,11 @@ public class CommitDiffPage extends RepositoryPage {
 
 		add(new CommitHeaderPanel("commitHeader", repositoryName, commit));
 
+		final List<String> imageExtensions = app().settings().getStrings(Keys.web.imageExtensions);
+		final ImageDiffHandler handler = new ImageDiffHandler(getContextUrl(), repositoryName,
+				parents.isEmpty() ? null : parents.get(0), commit.getName(), imageExtensions);
+		final DiffOutput diff = DiffUtils.getCommitDiff(r, commit, DiffOutputType.HTML, handler);
+
 		// add commit diffstat
 		int insertions = 0;
 		int deletions = 0;