From 9581dd0f52726b10c923038c28d5fe2170f0d1b6 Mon Sep 17 00:00:00 2001
From: epriestley <git@epriestley.com>
Date: Fri, 15 Feb 2019 09:53:23 -0800
Subject: [PATCH] Add Arcanist support for highlighting indent change intraline
 diffs

Summary:
Ref T13161. See D20181. This allows the intraline highlighter to accept new ">" and "<" spans and apply a different style for them.

The input pattern is `list<segment>`. Each segment is `pair<wild kind, int byte_length>`, i.e. wrap the next `byte_length` bytes in a span of kind `kind`.

Before this change, the possible kinds of segements are `0` (no intraline diff, do not highlight) or `1` (intraline diff, highlight in bright color).

D20181 adds `<` (depth decreased) and `>` (depth increased). These are like `1`, but add a different class so the UI can handle them differently.

Test Plan: See D20181.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13161

Differential Revision: https://secure.phabricator.com/D20182
---
 src/difference/ArcanistDiffUtils.php | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/difference/ArcanistDiffUtils.php b/src/difference/ArcanistDiffUtils.php
index a68a0532..0f798c9e 100644
--- a/src/difference/ArcanistDiffUtils.php
+++ b/src/difference/ArcanistDiffUtils.php
@@ -89,6 +89,9 @@ final class ArcanistDiffUtils extends Phobject {
     $highlight_o = '<span class="bright">';
     $highlight_c = '</span>';
 
+    $depth_in = '<span class="depth-in">';
+    $depth_out = '<span class="depth-out">';
+
     $is_html = false;
     if ($str instanceof PhutilSafeHTML) {
       $is_html = true;
@@ -107,11 +110,23 @@ final class ArcanistDiffUtils extends Phobject {
           $stack = array_shift($intra_stack);
           $s = $e;
           $e += $stack[1];
-        } while ($stack[0] == 0);
+        } while ($stack[0] === 0);
+
+        switch ($stack[0]) {
+          case '>':
+            $open_tag = $depth_in;
+            break;
+          case '<':
+            $open_tag = $depth_out;
+            break;
+          default:
+            $open_tag = $highlight_o;
+            break;
+        }
       }
 
       if (!$highlight && !$tag && !$ent && $p == $s) {
-        $buf .= $highlight_o;
+        $buf .= $open_tag;
         $highlight = true;
       }
 
@@ -139,7 +154,7 @@ final class ArcanistDiffUtils extends Phobject {
       if ($tag && $str[$i] == '>') {
         $tag = false;
         if ($highlight) {
-          $buf .= $highlight_o;
+          $buf .= $open_tag;
         }
       }