As shown in the comment at the beginning of theme_get_suggestions(), for a URL such as http://www.example.com/node/1/edit, the following default suggestions will be used.
page__node
page__node__%
page__node__1
page__node__edit
If you want to add page__node__edit__article
as suggestion, you need to implement hook_preprocess_page() in a module. The following code works for any content type.
function mymodule_preprocess_page(&$variables) {
if (!empty($variables['node']) && arg(2) == 'edit') {
// (1)
array_unshift($variables['theme_hook_suggestions'], 'page__node__edit__' . str_replace(array("/", "\\", "\0", '-'), array('', '', '', '_'), $variables['node']->type));
// (1)
}
}
If you want to be use not to apply the template file for, e.g., node/1/edit/revert, replace the code between // (1)
with the following one.
$arg3 = arg(3);
if (empty($arg3)) {
array_unshift($variables['theme_hook_suggestions'], 'page__node__edit__' . str_replace(array("/", "\\", "\0", '-'), array('', '', '', '_'), $variables['node']->type));
}