Opacity adjustments for image diffs

* ImageDiffHandler adds the slider; styled in gitblit.css
* imgdiff.js is a little bottom-loaded Javascript that adjusts the
  opacity on sliders' scroll events.
* The three diff pages add this bottom script to the page if needed
* GitBlitDiffFormatter: center image diffs.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/main/java/com/gitblit/wicket/pages/ComparePage.java b/src/main/java/com/gitblit/wicket/pages/ComparePage.java
index dae8d8ea..c0141eba 100644
--- a/src/main/java/com/gitblit/wicket/pages/ComparePage.java
+++ b/src/main/java/com/gitblit/wicket/pages/ComparePage.java
@@ -117,6 +117,9 @@ public class ComparePage extends RepositoryPage {
 					fromCommit.getName(), toCommit.getName(), imageExtensions);
 
 			final DiffOutput diff = DiffUtils.getDiff(r, fromCommit, toCommit, DiffOutputType.HTML, handler);
+			if (handler.getImgDiffCount() > 0) {
+				addBottomScript("scripts/imgdiff.js"); // Tiny support script for image diffs
+			}
 
 			// add compare diffstat
 			int insertions = 0;