--- /mnt/backup/backups/2004-12-26/var/www/twiki/lib/TWiki/UI/RDiff.pm	2004-09-27 21:23:32.000000000 +0200
+++ lib/TWiki/UI/RDiff.pm	2005-01-04 00:30:20.000000000 +0100
@@ -38,6 +38,8 @@
                     "u" => [ "#ffffff", "twikiDiffUnchangedText"],
                     "l" => [ "#eeeeee", "twikiDiffLineNumberHeader"] );
 
+my $globalDiffCount;
+
 #SVEN - new design.
 #main gets the info (NO MAJOR CHANGES NEEDED)
 #parseDiffs reads the diffs and interprets the information into types {"+", "-", "u", "c", "l"} (add, remove, unchanged, changed, lineNumber} where line number is for diffs that skip unchanged lines (diff -u etc)
@@ -181,8 +183,37 @@
   return $result;
 }
 
+# =========================
+=pod
+
+---+++ _anchor($text) ==> 'anchor' $text 'next' 'previous'
+   * Returns $text preceeded with an anchor and postfixed by a links to next and previous diffs
+   * Anchors are on the format diff001, diff002,...
+   * Uses $globalDiffCount to number anchors
+=cut
+# -------------------------
+sub _anchor
+{
+   $globalDiffCount++;
+   my $return = join('',
+                     '<a name="diff'
+                     ,sprintf("%03d",$globalDiffCount)
+                     ,'"></a>'
+                     ,$_[0]
+                     ,'&nbsp;&nbsp;[ <a class="twikiNextRdiff" href="#diff'
+                     ,sprintf("%03d",$globalDiffCount+1)
+                     ,'">next</a>');
+   $return.= join(''
+                  ,' | <a class="twikiNextRdiff" href="#diff'
+                  ,sprintf("%03d",$globalDiffCount-1)
+                  ,'">previous</a> ]') if ($globalDiffCount > 1);
+   $return.= ' | <a class="twikiNextRdiff" href="#diff000">to top</a> ]' if($globalDiffCount==1);
+
+   return $return;
+}
 
 # =========================
+
 =pod
 
 ---+++ _renderSequential( $topic, $diffType, $left, $right ) ==> $result
@@ -194,22 +225,25 @@
 | Return: =$result= | Formatted html text |
 | TODO: | this should move to Render.pm |
 
+Beware: 
+   * =$globalDiffCount= should be set to 0 before first call, ugly - but quick fix.
+   * Anchors to diffs are: #diff001 , #diff002 , etc.
 =cut
 # -------------------------
 sub _renderSequential
 {
-  my ( $topic, $diffType, $left, $right ) = @_;
+  my ( $topic, $diffType, $left, $right) = @_;
   my $result = "";
 
 #note: I have made the colspan 9 to make sure that it spans all columns (thought there are only 2 now)
   if ( $diffType eq "-") {
-    $result .= qq(<tr><td bgcolor="#FFD7D7" class="twikiDiffDeletedHeader" colspan ="9"><b> Deleted: </b>\n</td></tr>\n);
+    $result .= qq(<tr><td bgcolor="#FFD7D7" class="twikiDiffDeletedHeader" colspan ="9">).&_anchor("<b> Deleted: </b>").qq(\n</td></tr>\n);
     $result .= qq(<tr><td bgcolor="$diffColours{"-"}[0]" class="$diffColours{"-"}[1]" valign="top" width="1%">&lt;<br />&lt;</td>\n);
     $result .= qq(<td class="twikiDiffDeletedText">\n);
     $result .= _renderCellData( $left, $topic );
     $result .= qq(\n</td></tr>\n);
   } elsif ( $diffType eq "+") {
-    $result .= qq(<tr><td bgcolor="#D0FFD0" class="twikiDiffAddedHeader" colspan ="9"><b> Added:   </b>\n</td></tr>\n);
+    $result .= qq(<tr><td bgcolor="#D0FFD0" class="twikiDiffAddedHeader" colspan ="9">).&_anchor("<b> Added:   </b>").qq(\n</td></tr>\n);
     $result .= qq(<tr><td bgcolor="$diffColours{"+"}[0]" class="$diffColours{"+"}[1]" valign="top" width="1%">&gt;<br />&gt;</td>\n);
     $result .= qq(<td class="twikiDiffAddedText">\n);
     $result .= _renderCellData( $right, $topic );
@@ -220,7 +254,7 @@
     $result .= _renderCellData( $right, $topic );
     $result .= qq(\n</td></tr>\n);
   } elsif ( $diffType eq "c") {
-    $result .= qq(<tr><td bgcolor="#D0FFD0" class="twikiDiffChangedHeader" colspan ="9"><b> Changed: </b></td></tr>\n);
+    $result .= qq(<tr><td bgcolor="#D0FFD0" class="twikiDiffChangedHeader" colspan ="9">).&_anchor("<b> Changed: </b>").qq(</td></tr>\n);
     $result .= qq(<tr><td bgcolor="$diffColours{"-"}[0]" class="$diffColours{"-"}[1]" valign="top" width="1%">&lt;<br />&lt;</td>\n);
     $result .= qq(<td class="twikiDiffDeletedText">\n);
     $result .= _renderCellData( $left, $topic );
@@ -270,9 +304,10 @@
 	}
 	my $diffArray_ref = \@diffArray;
 
-    my $result = "<table class=\"twikiDiffTable\" width=\"100%\" cellspacing=\"0\">\n";
+    my $result = "<a name=\"diff000\"></a><table class=\"twikiDiffTable\" width=\"100%\" cellspacing=\"0\">\n";
     my $data = "";
     my $diff_ref = undef;
+	$globalDiffCount=0; 
     for my $next_ref ( @$diffArray_ref ) {
     	if (( @$next_ref[0] eq "l" ) && ( @$next_ref[1] eq 0 ) && (@$next_ref[2] eq 0)) {
 	    next;
@@ -306,7 +341,12 @@
 	    $result .= renderDebug ( @$diff_ref );
 	}
     }
-    return "$result\n<\/table>";
+	{
+		# horrible way to remove link from last diff - we ought to do better than parse once more
+		$globalDiffCount++;
+		$result=~ s/(\<a[^>]*$globalDiffCount[^>]*\>)next(\<\/a\>)/$1to end$2/s; 
+	}
+    return "$result\n<\/table><a name=\"diff".sprintf("%03d",$globalDiffCount).'"></a>';
 }
 
 # =========================
@@ -532,7 +572,9 @@
           $revisions .= " | &gt;";
         } else {
           $j = $i - 1;
-          $revisions .= " | <a href=\"$scriptUrlPath/rdiff%SCRIPTSUFFIX%/%WEB%/%TOPIC%?rev1=1.$i&amp;rev2=1.$j\">&gt;</a>";
+# CODE SMELLS: the context parameter should be configurable, not all people wish an 'inline' diff
+#         $revisions .= " | <a title=\"Changes from r1.$j to r1.$i\" href=\"$scriptUrlPath/rdiff%SCRIPTSUFFIX%/%WEB%/%TOPIC%?rev1=1.$i&amp;rev2=1.$j\">&gt;</a>";
+          $revisions .= " | <a title=\"Changes from r1.$j to r1.$i\" href=\"$scriptUrlPath/rdiff%SCRIPTSUFFIX%/%WEB%/%TOPIC%?rev1=1.$i&amp;rev2=1.$j&amp;context=9999#diff001\">&gt;</a>";
         }
       }
     }