gitweb: improve usability of projects search form

Refactor generating project search form into git_project_search_form().

Make text field wider and add on mouse over explanation (via "title"
attribute), add an option to use regular expressions, and replace
'Search:' label with [Search] button.

Also add "List all projects" link to make it easier to go back from search
result to list of all projects (note that an empty search term is
disallowed).

Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 3ab608c..c81743b 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -5158,6 +5158,26 @@
 
 # . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
 
+sub git_project_search_form {
+	my ($searchtext, $search_use_regexp);
+
+	print "<div class=\"projsearch\">\n";
+	print $cgi->startform(-method => 'get', -action => $my_uri) .
+	      $cgi->hidden(-name => 'a', -value => 'project_list') . "\n" .
+	      $cgi->textfield(-name => 's', -value => $searchtext,
+	                      -title => 'Search project by name and description',
+	                      -size => 60) . "\n" .
+	      "<span title=\"Extended regular expression\">" .
+	      $cgi->checkbox(-name => 'sr', -value => 1, -label => 're',
+	                     -checked => $search_use_regexp) .
+	      "</span>\n" .
+	      $cgi->submit(-name => 'btnS', -value => 'Search') .
+	      $cgi->end_form() . "\n" .
+	      $cgi->a({-href => href(project => undef, searchtext => undef)},
+	              'List all projects') . "<br />\n";
+	print "</div>\n";
+}
+
 # fills project list info (age, description, owner, category, forks)
 # for each project in the list, removing invalid projects from
 # returned list
@@ -6025,11 +6045,8 @@
 		insert_file($home_text);
 		print "</div>\n";
 	}
-	print $cgi->startform(-method => "get") .
-	      "<p class=\"projsearch\">Search:\n" .
-	      $cgi->textfield(-name => "s", -value => $searchtext) . "\n" .
-	      "</p>" .
-	      $cgi->end_form() . "\n";
+
+	git_project_search_form($searchtext, $search_use_regexp);
 	git_project_list_body(\@list, $order);
 	git_footer_html();
 }