How does the theme (' Item-list ', Array (' Items ' =>array (' aaa ', ' BBB ')) work?

$items [' items '] = Array (    l (' Configure ', ' admin/config '),    L (' Structure ', ' admin/structure '),); $theme =  Theme (' Item_list ', $items);

1, judging if all the modules are loaded,

if (!module_load_all (NULL) &&! defined (' Maintenance_mode ')) {    thrownewException(t (' theme () May is called until all modules is loaded. ') ));  }

2, get all the themeregistry information, this information is the Hook_theme array of all module definitions, and merge many default information, such as process function, function, render array, variables , etc

$hooks = theme_get_registry (FALSE);

3, get the themeregistry information corresponding to this Themehook

$info $hooks [$hook];

4, if Hook_theme defines the includes, then load the function

if (! Empty ($info[' includes '])) {    foreach ($infoas$include _file) {      include_once  $include _file;    }  }

5, $variable and themeregistry correspond to the variable merger of this hook.

  if (! Empty ($info[' variables '])) {    $variables$info[' variables '];  }

6, $info inside process preprocess function is called

$processor _function ($variables$hook _clone);

7, if $variable[' theme_hook_suggestion ' is changed in the process preprocess function, it will reload $hook

$info $hooks [$suggestion];

8, the function inside the $info will be transferred to handle $variable

$output $info [' function '] ($variables);

How does the theme (' Item-list ', Array (' Items ' =>array (' aaa ', ' BBB ')) work?