#230 - Improve empty folder navigation.

Empty folders are automatically skipped when browsing repository tree  (similar to github "folder jumping" feature).

1 files changed, 92 insertions, 0 deletions

diff --git a/src/main/java/com/gitblit/utils/PathUtils.java b/src/main/java/com/gitblit/utils/PathUtils.java
new file mode 100644
index 00000000..a3c7d8d6
--- /dev/null
+++ b/src/main/java/com/gitblit/utils/PathUtils.java
@@ -0,0 +1,92 @@
+package com.gitblit.utils;
+
+import com.google.common.base.Joiner;
+import com.google.common.base.Splitter;
+import com.google.common.collect.Iterables;
+
+import java.util.*;
+
+/**
+ *  Utils for handling path strings
+ *
+ */
+public class PathUtils {
+
+    private PathUtils() {}
+
+    /**
+     *  Compress paths containing no files
+     *
+     * @param paths lines from `git ls-tree -r --name-only ${branch}`
+     * @return compressed paths
+     */
+    public static List<String> compressPaths(final Iterable<String> paths)  {
+
+        ArrayList<String> pathList = new ArrayList<>();
+        Map<String, List<String[]>> folderRoots = new LinkedHashMap<>();
+
+        for (String s: paths) {
+            String[] components = s.split("/");
+
+            // File in current directory
+            if (components.length == 1) {
+                pathList.add(components[0]);
+
+                // Directory path
+            } else {
+                List<String[]> rootedPaths = folderRoots.get(components[0]);
+                if (rootedPaths == null) {
+                    rootedPaths = new ArrayList<>();
+                }
+                rootedPaths.add(components);
+                folderRoots.put(components[0], rootedPaths);
+            }
+        }
+
+        for (String folder: folderRoots.keySet()) {
+            List<String[]> matchingPaths = folderRoots.get(folder);
+
+            if (matchingPaths.size() == 1) {
+                pathList.add(toStringPath(matchingPaths.get(0)));
+            } else {
+                pathList.add(longestCommonSequence(matchingPaths));
+            }
+        }
+        return pathList;
+    }
+
+    /**
+     *  Get last path component
+     *
+     *
+     * @param path string path separated by slashes
+     * @return rightmost entry
+     */
+    public static String getLastPathComponent(final String path) {
+        return Iterables.getLast(Splitter.on("/").omitEmptyStrings().split(path), path);
+    }
+
+    private static String toStringPath(final String[] pathComponents) {
+        List<String> tmp = Arrays.asList(pathComponents);
+        return Joiner.on('/').join(tmp.subList(0,tmp.size()-1)) + '/';
+    }
+
+
+    private static String longestCommonSequence(final List<String[]> paths) {
+
+        StringBuilder path = new StringBuilder();
+
+        for (int i = 0; i < paths.get(0).length; i++) {
+            String current = paths.get(0)[i];
+            for (int j = 1; j < paths.size(); j++) {
+                if (!current.equals(paths.get(j)[i])) {
+                    return path.toString();
+                }
+            }
+            path.append(current);
+            path.append('/');
+        }
+        return path.toString();
+    }
+
+}