/*
 * File      : topwin.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006 - 2009, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2009-10-16     Bernard      first version
 */
#include "topwin.h"
#include "mouse.h"

#include <rtgui/dlist.h>
#include <rtgui/event.h>
#include <rtgui/image.h>
#include <rtgui/rtgui_theme.h>
#include <rtgui/rtgui_system.h>
#include <rtgui/rtgui_app.h>
#include <rtgui/widgets/window.h>

/* This list is divided into two parts. The first part is the shown list, in
 * which all the windows have the WINTITLE_SHOWN flag set. Second part is the
 * hidden items, in which all the windows don't have WINTITLE_SHOWN flag.
 *
 * The active window is the one that would receive kbd events. It should always
 * be in the first tree. The order of this list is the order of the windows.
 * Top window can always clip the window beneath it when the two
 * overlapping. Child window can always clip it's parent. Slibing windows can
 * clip each other with the same rule as this list. Each child list is the same
 * as _rtgui_topwin_list. This forms the hierarchy tree structure of all
 * windows.
 *
 * Thus, the left most leaf of the tree is the top most window and the right
 * most root node is the bottom window.  The hidden part have no specific
 * order.
 */
static struct rtgui_dlist_node _rtgui_topwin_list;
#define get_topwin_from_list(list_entry) \
    (rtgui_dlist_entry((list_entry), struct rtgui_topwin, list))

#define IS_ROOT_WIN(topwin) ((topwin)->parent == RT_NULL)

static struct rt_semaphore _rtgui_topwin_lock;

static void rtgui_topwin_update_clip(void);
static void rtgui_topwin_redraw(struct rtgui_rect *rect);
static void _rtgui_topwin_activate_next(enum rtgui_topwin_flag);

void rtgui_topwin_init(void)
{
    /* init window list */
    rtgui_dlist_init(&_rtgui_topwin_list);

    rt_sem_init(&_rtgui_topwin_lock,
                "topwin", 1, RT_IPC_FLAG_FIFO);
}

static struct rtgui_topwin *rtgui_topwin_search_in_list(struct rtgui_win *window,
        struct rtgui_dlist_node *list)
{
    /* TODO: use a cache to speed up the search. */
    struct rtgui_dlist_node *node;
    struct rtgui_topwin *topwin;

    /* the action is tend to operate on the top most window. So we search in a
     * depth first order.
     */
    rtgui_dlist_foreach(node, list, next)
    {
        topwin = rtgui_dlist_entry(node, struct rtgui_topwin, list);

        /* is this node? */
        if (topwin->wid == window)
        {
            return topwin;
        }

        topwin = rtgui_topwin_search_in_list(window, &topwin->child_list);
        if (topwin != RT_NULL)
            return topwin;
    }

    return RT_NULL;
}

/* add a window to window list[hide] */
rt_err_t rtgui_topwin_add(struct rtgui_event_win_create *event)
{
    struct rtgui_topwin *topwin;

    topwin = rtgui_malloc(sizeof(struct rtgui_topwin));
    if (topwin == RT_NULL)
        return -RT_ERROR;

    topwin->wid    = event->wid;
#ifdef RTGUI_USING_SMALL_SIZE
    topwin->extent = RTGUI_WIDGET(event->wid)->extent;
#else
    topwin->extent = event->extent;
#endif
    topwin->tid    = event->parent.sender;

    if (event->parent_window == RT_NULL)
    {
        topwin->parent = RT_NULL;
        rtgui_dlist_insert_before(&_rtgui_topwin_list, &topwin->list);
    }
    else
    {
        topwin->parent = rtgui_topwin_search_in_list(event->parent_window, &_rtgui_topwin_list);
        if (topwin->parent == RT_NULL)
        {
            /* parent does not exist. Orphan window? */
            rtgui_free(topwin);
            return -RT_ERROR;
        }
        rtgui_dlist_insert_before(&topwin->parent->child_list, &topwin->list);
    }

    rtgui_dlist_init(&topwin->child_list);

    topwin->flag = 0;
    if (event->parent.user & RTGUI_WIN_STYLE_NO_TITLE) topwin->flag |= WINTITLE_NO;
    if (event->parent.user & RTGUI_WIN_STYLE_CLOSEBOX) topwin->flag |= WINTITLE_CLOSEBOX;
    if (!(event->parent.user & RTGUI_WIN_STYLE_NO_BORDER)) topwin->flag |= WINTITLE_BORDER;
    if (event->parent.user & RTGUI_WIN_STYLE_NO_FOCUS) topwin->flag |= WINTITLE_NOFOCUS;
    if (event->parent.user & RTGUI_WIN_STYLE_ONTOP) topwin->flag |= WINTITLE_ONTOP;
    if (event->parent.user & RTGUI_WIN_STYLE_ONBTM) topwin->flag |= WINTITLE_ONBTM;

    if (!(topwin->flag & WINTITLE_NO) || (topwin->flag & WINTITLE_BORDER))
    {
        /* get win extent */
        rtgui_rect_t rect = topwin->extent;

        /* add border rect */
        if (topwin->flag & WINTITLE_BORDER)
        {
            rtgui_rect_inflate(&rect, WINTITLE_BORDER_SIZE);
        }

        /* add title rect */
        if (!(topwin->flag & WINTITLE_NO)) rect.y1 -= WINTITLE_HEIGHT;

#ifdef RTGUI_USING_SMALL_SIZE
        topwin->title = rtgui_wintitle_create(topwin->wid, event->wid->title);
#else
        topwin->title = rtgui_wintitle_create(topwin->wid, (const char *)event->title);
#endif
        rtgui_widget_set_rect(RTGUI_WIDGET(topwin->title), &rect);

        /* update clip info */
        rtgui_region_subtract_rect(&(RTGUI_WIDGET(topwin->title)->clip),
                                   &(RTGUI_WIDGET(topwin->title)->clip),
                                   &(topwin->extent));
    }
    else
        topwin->title = RT_NULL;

    rtgui_list_init(&topwin->monitor_list);

    return RT_EOK;
}

static struct rtgui_topwin *_rtgui_topwin_get_root_win(struct rtgui_topwin *topwin)
{
    struct rtgui_topwin *topparent;

    RT_ASSERT(topwin != RT_NULL);

    topparent = topwin;
    while (topparent && !IS_ROOT_WIN(topparent))
        topparent = topparent->parent;
    return topparent;
}

static struct rtgui_topwin *_rtgui_topwin_get_topmost_child_shown(struct rtgui_topwin *topwin)
{
    RT_ASSERT(topwin != RT_NULL);

    while (!(rtgui_dlist_isempty(&topwin->child_list)) &&
            get_topwin_from_list(topwin->child_list.next)->flag &WINTITLE_SHOWN)
        topwin = get_topwin_from_list(topwin->child_list.next);
    return topwin;
}

static rt_bool_t _rtgui_topwin_in_layer(struct rtgui_topwin *topwin, enum rtgui_topwin_flag flag)
{
    return (topwin->flag & (WINTITLE_ONTOP | WINTITLE_ONBTM))
           == (flag & (WINTITLE_ONTOP | WINTITLE_ONBTM));
}

/* find the topmost window shown in the layer set by flag. The flag has many
 * other infomations but we only use the ONTOP/ONBTM */
static struct rtgui_topwin *_rtgui_topwin_get_topmost_window_shown(enum rtgui_topwin_flag flag)
{
    struct rtgui_dlist_node *node;

    rtgui_dlist_foreach(node, &_rtgui_topwin_list, next)
    {
        struct rtgui_topwin *topwin = get_topwin_from_list(node);

        /* reach the hidden region no window shown in current layer */
        if (!(topwin->flag & WINTITLE_SHOWN))
            return RT_NULL;

        if (_rtgui_topwin_in_layer(topwin, flag))
            return _rtgui_topwin_get_topmost_child_shown(topwin);
    }
    /* no window in current layer is shown */
    return RT_NULL;
}

/* a hidden parent will hide it's children. Top level window can be shown at
 * any time. */
static rt_bool_t _rtgui_topwin_could_show(struct rtgui_topwin *topwin)
{
    struct rtgui_topwin *parent;

    RT_ASSERT(topwin != RT_NULL);

    for (parent = topwin->parent; parent != RT_NULL; parent = parent->parent)
    {
        if (!(parent->flag & WINTITLE_SHOWN))
            return RT_FALSE;
    }
    return RT_TRUE;
}

static void _rtgui_topwin_union_region_tree(struct rtgui_topwin *topwin,
        struct rtgui_region *region)
{
    struct rtgui_dlist_node *node;

    RT_ASSERT(topwin != RT_NULL);

    rtgui_dlist_foreach(node, &topwin->child_list, next)
    _rtgui_topwin_union_region_tree(get_topwin_from_list(node), region);

    if (topwin->title != RT_NULL)
        rtgui_region_union_rect(region, region, &RTGUI_WIDGET(topwin->title)->extent);
    else
        rtgui_region_union_rect(region, region, &topwin->extent);
}

/* The return value of this function is the next node in tree.
 *
 * As we freed the node in this function, it would be a null reference error of
 * the caller iterate the tree normally.
 */
static struct rtgui_dlist_node *_rtgui_topwin_free_tree(struct rtgui_topwin *topwin)
{
    struct rtgui_dlist_node *node, *next_node;

    RT_ASSERT(topwin != RT_NULL);

    node = topwin->child_list.next;
    while (node != &topwin->child_list)
        node = _rtgui_topwin_free_tree(get_topwin_from_list(node));

    next_node = topwin->list.next;
    rtgui_dlist_remove(&topwin->list);

    /* free the monitor rect list, topwin node and title */
    while (topwin->monitor_list.next != RT_NULL)
    {
        struct rtgui_mouse_monitor *monitor = rtgui_list_entry(topwin->monitor_list.next,
                                              struct rtgui_mouse_monitor, list);

        topwin->monitor_list.next = topwin->monitor_list.next->next;
        rtgui_free(monitor);
    }

    /* destroy win title */
    rtgui_wintitle_destroy(topwin->title);
    topwin->title = RT_NULL;

    rtgui_free(topwin);
    return next_node;
}

rt_err_t rtgui_topwin_remove(struct rtgui_win *wid)
{
    struct rtgui_topwin *topwin, *old_focus;
    struct rtgui_region region;

    /* find the topwin node */
    topwin = rtgui_topwin_search_in_list(wid, &_rtgui_topwin_list);

    if (topwin == RT_NULL)
        return -RT_ERROR;

    rtgui_region_init(&region);

    old_focus = rtgui_topwin_get_focus();

    /* remove the root from _rtgui_topwin_list will remove the whole tree from
     * _rtgui_topwin_list. */
    rtgui_dlist_remove(&topwin->list);

    if (old_focus == topwin)
    {
        _rtgui_topwin_activate_next(topwin->flag);
    }

    if (topwin->flag & WINTITLE_SHOWN)
    {
        rtgui_topwin_update_clip();
        /* redraw the old rect */
        _rtgui_topwin_union_region_tree(topwin, &region);
        rtgui_topwin_redraw(rtgui_region_extents(&region));
    }

    _rtgui_topwin_free_tree(topwin);

    return RT_EOK;
}

/* neither deactivate the old focus nor change _rtgui_topwin_list.
 * Suitable to be called when the first item is the window to be activated
 * already. */
static void _rtgui_topwin_only_activate(struct rtgui_topwin *topwin)
{
    struct rtgui_event_win event;

    RT_ASSERT(topwin != RT_NULL);

    if (topwin->flag & WINTITLE_NOFOCUS)
        return;

    /* activate the raised window */
    RTGUI_EVENT_WIN_ACTIVATE_INIT(&event);

    topwin->flag |= WINTITLE_ACTIVATE;

    event.wid = topwin->wid;
    rtgui_send(topwin->tid, &(event.parent), sizeof(struct rtgui_event_win));

    /* redraw title */
    if (topwin->title != RT_NULL)
    {
        rtgui_theme_draw_win(topwin);
    }
}

/* activate next window in the same layer as flag. The flag has many other
 * infomations but we only use the ONTOP/ONBTM */
static void _rtgui_topwin_activate_next(enum rtgui_topwin_flag flag)
{
    struct rtgui_topwin *topwin;

    topwin = _rtgui_topwin_get_topmost_window_shown(flag);
    if (topwin == RT_NULL)
        return;

    _rtgui_topwin_only_activate(topwin);
}

/* this function does not update the clip(to avoid doubel clipping). So if the
 * tree has changed, make sure it has already updated outside. */
static void _rtgui_topwin_deactivate(struct rtgui_topwin *topwin)
{
    struct rtgui_event_win event;

    RT_ASSERT(topwin != RT_NULL);
    RT_ASSERT(topwin->tid != RT_NULL);

    RTGUI_EVENT_WIN_DEACTIVATE_INIT(&event);
    event.wid = topwin->wid;
    rtgui_send(topwin->tid,
               &event.parent, sizeof(struct rtgui_event_win));

    topwin->flag &= ~WINTITLE_ACTIVATE;

    /* redraw title */
    if (topwin->title != RT_NULL)
    {
        rtgui_theme_draw_win(topwin);
    }
}

static void _rtgui_topwin_move_whole_tree2top(struct rtgui_topwin *topwin)
{
    struct rtgui_topwin *topparent;

    RT_ASSERT(topwin != RT_NULL);

    /* move the whole tree */
    topparent = _rtgui_topwin_get_root_win(topwin);
    RT_ASSERT(topparent != RT_NULL);

    /* remove node from hidden list */
    rtgui_dlist_remove(&topparent->list);
    /* add node to show list */
    if (topwin->flag & WINTITLE_ONTOP)
    {
        rtgui_dlist_insert_after(&_rtgui_topwin_list, &(topparent->list));
    }
    else if (topwin->flag & WINTITLE_ONBTM)
    {
        /* botton layer window, before the fisrt bottom window or hidden window. */
        struct rtgui_topwin *ntopwin = get_topwin_from_list(&_rtgui_topwin_list);
        struct rtgui_dlist_node *node;

        rtgui_dlist_foreach(node, &_rtgui_topwin_list, next)
        {
            ntopwin = get_topwin_from_list(node);
            if ((ntopwin->flag & WINTITLE_ONBTM)
                    || !(ntopwin->flag & WINTITLE_SHOWN))
                break;
        }
        /* all other windows are shown top/normal layer windows. Insert it as
         * the last window. */
        if (node == &_rtgui_topwin_list)
            rtgui_dlist_insert_before(&_rtgui_topwin_list, &(topparent->list));
        else
            rtgui_dlist_insert_before(&ntopwin->list, &(topparent->list));
    }
    else
    {
        /* normal layer window, before the fisrt shown normal layer window. */
        struct rtgui_topwin *ntopwin = get_topwin_from_list(&_rtgui_topwin_list);
        struct rtgui_dlist_node *node;

        rtgui_dlist_foreach(node, &_rtgui_topwin_list, next)
        {
            ntopwin = get_topwin_from_list(node);
            if (!((ntopwin->flag & WINTITLE_ONTOP)
                    && (ntopwin->flag & WINTITLE_SHOWN)))
                break;
        }
        /* all other windows are shown top layer windows. Insert it as
         * the last window. */
        if (node == &_rtgui_topwin_list)
            rtgui_dlist_insert_before(&_rtgui_topwin_list, &(topparent->list));
        else
            rtgui_dlist_insert_before(&ntopwin->list, &(topparent->list));
    }
}

static void _rtgui_topwin_raise_in_sibling(struct rtgui_topwin *topwin)
{
    struct rtgui_dlist_node *win_level;

    RT_ASSERT(topwin != RT_NULL);

    if (topwin->parent == RT_NULL)
        win_level = &_rtgui_topwin_list;
    else
        win_level = &topwin->parent->child_list;
    rtgui_dlist_remove(&topwin->list);
    rtgui_dlist_insert_after(win_level, &topwin->list);
}

/* it will do 2 things. One is moving the whole tree(the root of the tree) to
 * the front and the other is moving topwin to the front of it's siblings. */
static void _rtgui_topwin_raise_tree_from_root(struct rtgui_topwin *topwin)
{
    RT_ASSERT(topwin != RT_NULL);

    _rtgui_topwin_move_whole_tree2top(topwin);
    /* root win is aleady moved by _rtgui_topwin_move_whole_tree2top */
    if (!IS_ROOT_WIN(topwin))
        _rtgui_topwin_raise_in_sibling(topwin);
}

/* activate a win means:
 * - deactivate the old focus win if any
 * - raise the window to the front of it's siblings
 * - activate a win
 */
rt_err_t rtgui_topwin_activate(struct rtgui_event_win_activate *event)
{
    struct rtgui_topwin *topwin;

    RT_ASSERT(event);

    topwin = rtgui_topwin_search_in_list(event->wid, &_rtgui_topwin_list);
    if (topwin == RT_NULL)
        return -RT_ERROR;

    return rtgui_topwin_activate_topwin(topwin);
}

static void _rtgui_topwin_draw_tree(struct rtgui_topwin *topwin, struct rtgui_event_paint *epaint)
{
    struct rtgui_dlist_node *node;

    if (topwin->title != RT_NULL)
    {
        rtgui_theme_draw_win(topwin);
    }

    epaint->wid = topwin->wid;
    rtgui_send(topwin->tid, &(epaint->parent), sizeof(struct rtgui_event_paint));

    rtgui_dlist_foreach(node, &topwin->child_list, prev)
    {
        if (!(get_topwin_from_list(node)->flag & WINTITLE_SHOWN))
            return;
        _rtgui_topwin_draw_tree(get_topwin_from_list(node), epaint);
    }
}

rt_err_t rtgui_topwin_activate_topwin(struct rtgui_topwin *topwin)
{
    struct rtgui_topwin *old_focus_topwin;
    struct rtgui_event_paint epaint;

    RT_ASSERT(topwin != RT_NULL);

    RTGUI_EVENT_PAINT_INIT(&epaint);

    if (!(topwin->flag & WINTITLE_SHOWN))
        return -RT_ERROR;

    if (topwin->flag & WINTITLE_NOFOCUS)
    {
        /* just raise and show, not affect others. */
        _rtgui_topwin_raise_tree_from_root(topwin);
        rtgui_topwin_update_clip();
        _rtgui_topwin_draw_tree(topwin, &epaint);
        return RT_EOK;
    }

    if (topwin->flag & WINTITLE_ACTIVATE)
        return RT_EOK;

    old_focus_topwin = rtgui_topwin_get_focus();
    /* if topwin has the focus, it shoule have WINTITLE_ACTIVATE set and
     * returned above. */
    RT_ASSERT(old_focus_topwin != topwin);

    _rtgui_topwin_raise_tree_from_root(topwin);
    /* clip before active the window, so we could get right boarder region. */
    rtgui_topwin_update_clip();

    if (old_focus_topwin != RT_NULL)
    {
        /* deactivate the old focus window firstly, otherwise it will make the new
         * window invisible. */
        _rtgui_topwin_deactivate(old_focus_topwin);
    }

    _rtgui_topwin_only_activate(topwin);

    _rtgui_topwin_draw_tree(topwin, &epaint);

    return RT_EOK;
}

/* map func to the topwin tree in preorder.
 *
 * Remember that we are in a embedded system so write the @param func memory
 * efficiently.
 */
rt_inline void _rtgui_topwin_preorder_map(struct rtgui_topwin *topwin, void (*func)(struct rtgui_topwin *))
{
    struct rtgui_dlist_node *child;

    RT_ASSERT(topwin != RT_NULL);
    RT_ASSERT(func != RT_NULL);

    func(topwin);

    rtgui_dlist_foreach(child, &topwin->child_list, next)
    _rtgui_topwin_preorder_map(get_topwin_from_list(child), func);
}

rt_inline void _rtgui_topwin_mark_hidden(struct rtgui_topwin *topwin)
{
    topwin->flag &= ~WINTITLE_SHOWN;
    if (topwin->title != RT_NULL)
    {
        RTGUI_WIDGET_HIDE(topwin->title);
    }
    RTGUI_WIDGET_HIDE(topwin->wid);
}

rt_inline void _rtgui_topwin_mark_shown(struct rtgui_topwin *topwin)
{
    if (!(topwin->flag & WINTITLE_SHOWN)
            && RTGUI_WIDGET_IS_HIDE(topwin->wid))
        return;

    topwin->flag |= WINTITLE_SHOWN;
    if (topwin->title != RT_NULL)
    {
        RTGUI_WIDGET_UNHIDE(topwin->title);
    }
    RTGUI_WIDGET_UNHIDE(topwin->wid);
}

rt_err_t rtgui_topwin_show(struct rtgui_event_win *event)
{
    struct rtgui_topwin *topwin;
    struct rtgui_win *wid = event->wid;

    topwin = rtgui_topwin_search_in_list(wid, &_rtgui_topwin_list);
    /* no such a window recorded */
    if (topwin == RT_NULL)
        return -RT_ERROR;

    /* if the parent is hidden, just mark it as shown. It will be shown when
     * the parent is shown. */
    if (!_rtgui_topwin_could_show(topwin))
    {
        topwin->flag |= WINTITLE_SHOWN;
        _rtgui_topwin_raise_in_sibling(topwin);

        return -RT_ERROR;
    }

    _rtgui_topwin_preorder_map(topwin, _rtgui_topwin_mark_shown);
    rtgui_topwin_activate_topwin(topwin);

    return RT_EOK;
}

static void _rtgui_topwin_clear_modal_tree(struct rtgui_topwin *topwin)
{
    struct rtgui_dlist_node *node;

    RT_ASSERT(topwin != RT_NULL);
    RT_ASSERT(topwin->parent != RT_NULL);

    while (!IS_ROOT_WIN(topwin))
    {
        rtgui_dlist_foreach(node, &topwin->parent->child_list, next)
        get_topwin_from_list(node)->flag &= ~WINTITLE_MODALED;
        topwin = topwin->parent;
    }
    /* clear the modal flag of the root window */
    topwin->flag &= ~WINTITLE_MODALED;
}

/* hide a window */
rt_err_t rtgui_topwin_hide(struct rtgui_event_win *event)
{
    struct rtgui_topwin *topwin;
    struct rtgui_topwin *old_focus_topwin = rtgui_topwin_get_focus();
    struct rtgui_win    *wid = event->wid;
    struct rtgui_dlist_node *containing_list;

    /* find in show list */
    topwin = rtgui_topwin_search_in_list(wid, &_rtgui_topwin_list);
    if (topwin == RT_NULL)
    {
        return -RT_ERROR;
    }
    if (!(topwin->flag & WINTITLE_SHOWN))
    {
        return RT_EOK;
    }

    old_focus_topwin = rtgui_topwin_get_focus();

    _rtgui_topwin_preorder_map(topwin, _rtgui_topwin_mark_hidden);

    if (topwin->parent == RT_NULL)
        containing_list = &_rtgui_topwin_list;
    else
        containing_list = &topwin->parent->child_list;

    rtgui_dlist_remove(&topwin->list);
    rtgui_dlist_insert_before(containing_list, &topwin->list);

    /* update clip info */
    rtgui_topwin_update_clip();

    /* redraw the old rect */
    rtgui_topwin_redraw(&(topwin->extent));

    if (topwin->flag & WINTITLE_MODALING)
    {
        _rtgui_topwin_clear_modal_tree(topwin);
        topwin->flag &= ~WINTITLE_MODALING;
    }

    if (old_focus_topwin == topwin)
    {
        _rtgui_topwin_activate_next(topwin->flag);
    }

    topwin->flag &= ~WINTITLE_ACTIVATE;

    return RT_EOK;
}

/* move top window */
rt_err_t rtgui_topwin_move(struct rtgui_event_win_move *event)
{
    struct rtgui_topwin *topwin;
    int dx, dy;
    rtgui_rect_t old_rect; /* the old topwin coverage area */
    struct rtgui_list_node *node;

    /* find in show list */
    topwin = rtgui_topwin_search_in_list(event->wid, &_rtgui_topwin_list);
    if (topwin == RT_NULL ||
            !(topwin->flag & WINTITLE_SHOWN))
    {
        return -RT_ERROR;
    }

    /* get the delta move x, y */
    dx = event->x - topwin->extent.x1;
    dy = event->y - topwin->extent.y1;

    old_rect = topwin->extent;
    /* move window rect */
    rtgui_rect_moveto(&(topwin->extent), dx, dy);

    /* move window title */
    if (topwin->title != RT_NULL)
    {
        old_rect = RTGUI_WIDGET(topwin->title)->extent;
        rtgui_widget_move_to_logic(RTGUI_WIDGET(topwin->title), dx, dy);
    }

    /* move the monitor rect list */
    rtgui_list_foreach(node, &(topwin->monitor_list))
    {
        struct rtgui_mouse_monitor *monitor = rtgui_list_entry(node,
                                              struct rtgui_mouse_monitor,
                                              list);
        rtgui_rect_moveto(&(monitor->rect), dx, dy);
    }

    /* update windows clip info */
    rtgui_topwin_update_clip();

    /* update old window coverage area */
    rtgui_topwin_redraw(&old_rect);

    /* update top window title */
    if (topwin->title != RT_NULL)
        rtgui_theme_draw_win(topwin);
    if (rtgui_rect_is_intersect(&old_rect, &(topwin->extent)) != RT_EOK)
    {
        /*
         * the old rect is not intersect with moved rect,
         * re-paint window
         */
        struct rtgui_event_paint epaint;
        RTGUI_EVENT_PAINT_INIT(&epaint);
        epaint.wid = topwin->wid;
        rtgui_send(topwin->tid, &(epaint.parent), sizeof(epaint));
    }

    return RT_EOK;
}

/*
 * resize a top win
 * Note: currently, only support resize hidden window
 */
void rtgui_topwin_resize(struct rtgui_win *wid, rtgui_rect_t *rect)
{
    struct rtgui_topwin *topwin;
    struct rtgui_region region;

    /* find in show list */
    topwin = rtgui_topwin_search_in_list(wid, &_rtgui_topwin_list);
    if (topwin == RT_NULL ||
            !(topwin->flag & WINTITLE_SHOWN))
        return;

    /* record the old rect */
    rtgui_region_init_with_extents(&region, &topwin->extent);
    /* union the new rect so this is the region we should redraw */
    rtgui_region_union_rect(&region, &region, rect);

    topwin->extent = *rect;

    if (topwin->title != RT_NULL)
    {
        /* get win extent */
        rtgui_rect_t rect = topwin->extent;

        /* add border rect */
        if (topwin->flag & WINTITLE_BORDER)
        {
            rtgui_rect_inflate(&rect, WINTITLE_BORDER_SIZE);
        }

        /* add title rect */
        if (!(topwin->flag & WINTITLE_NO))
            rect.y1 -= WINTITLE_HEIGHT;

        RTGUI_WIDGET(topwin->title)->extent = rect;
    }

    /* update windows clip info */
    rtgui_topwin_update_clip();

    /* update old window coverage area */
    rtgui_topwin_redraw(rtgui_region_extents(&region));
}

static struct rtgui_topwin *_rtgui_topwin_get_focus_from_list(struct rtgui_dlist_node *list)
{
    struct rtgui_dlist_node *node;

    RT_ASSERT(list != RT_NULL);

    rtgui_dlist_foreach(node, list, next)
    {
        struct rtgui_topwin *child = get_topwin_from_list(node);
        if (child->flag & WINTITLE_ACTIVATE)
            return child;

        child = _rtgui_topwin_get_focus_from_list(&child->child_list);
        if (child != RT_NULL)
            return child;
    }

    return RT_NULL;
}

struct rtgui_topwin *rtgui_topwin_get_focus(void)
{
    return _rtgui_topwin_get_focus_from_list(&_rtgui_topwin_list);
}

static struct rtgui_topwin *_rtgui_topwin_get_wnd_from_tree(struct rtgui_dlist_node *list,
        int x, int y,
        rt_bool_t exclude_modaled)
{
    struct rtgui_dlist_node *node;
    struct rtgui_topwin *topwin, *target;

    RT_ASSERT(list != RT_NULL);

    rtgui_dlist_foreach(node, list, next)
    {
        topwin = get_topwin_from_list(node);
        if (!(topwin->flag & WINTITLE_SHOWN))
            break;

        /* if higher window have this point, return it */
        target = _rtgui_topwin_get_wnd_from_tree(&topwin->child_list, x, y, exclude_modaled);
        if (target != RT_NULL)
            return target;

        if (exclude_modaled && (topwin->flag & WINTITLE_MODALED))
            break;

        if ((topwin->title != RT_NULL) &&
                rtgui_rect_contains_point(&(RTGUI_WIDGET(topwin->title)->extent), x, y) == RT_EOK)
        {
            return topwin;
        }
        else if (rtgui_rect_contains_point(&(topwin->extent), x, y) == RT_EOK)
        {
            return topwin;
        }
    }

    return RT_NULL;
}

struct rtgui_topwin *rtgui_topwin_get_wnd(int x, int y)
{
    return _rtgui_topwin_get_wnd_from_tree(&_rtgui_topwin_list, x, y, RT_FALSE);
}

struct rtgui_topwin *rtgui_topwin_get_wnd_no_modaled(int x, int y)
{
    return _rtgui_topwin_get_wnd_from_tree(&_rtgui_topwin_list, x, y, RT_TRUE);
}

/* clip region from topwin, and the windows beneath it. */
rt_inline void _rtgui_topwin_clip_to_region(struct rtgui_region *region,
        struct rtgui_topwin *topwin)
{
    RT_ASSERT(region != RT_NULL);
    RT_ASSERT(topwin != RT_NULL);

    if (topwin->title != RT_NULL)
    {
        rtgui_region_reset(&(RTGUI_WIDGET(topwin->title)->clip),
                           &(RTGUI_WIDGET(topwin->title)->extent));
        rtgui_region_intersect(&(RTGUI_WIDGET(topwin->title)->clip),
                               &(RTGUI_WIDGET(topwin->title)->clip),
                               region);
        rtgui_region_subtract_rect(&(RTGUI_WIDGET(topwin->title)->clip),
                                   &(RTGUI_WIDGET(topwin->title)->clip),
                                   &topwin->extent);
    }

    rtgui_region_reset(&RTGUI_WIDGET(topwin->wid)->clip,
                       &RTGUI_WIDGET(topwin->wid)->extent);
    rtgui_region_intersect(&RTGUI_WIDGET(topwin->wid)->clip,
                           &RTGUI_WIDGET(topwin->wid)->clip,
                           region);
}

static void rtgui_topwin_update_clip(void)
{
    struct rtgui_topwin *top;
    struct rtgui_event_clip_info eclip;
    /* Note that the region is a "female die", that means it's the region you
     * can paint to, not the region covered by others.
     */
    struct rtgui_region region_available;

    if (rtgui_dlist_isempty(&_rtgui_topwin_list) ||
            !(get_topwin_from_list(_rtgui_topwin_list.next)->flag & WINTITLE_SHOWN))
        return;

    RTGUI_EVENT_CLIP_INFO_INIT(&eclip);

    rtgui_region_init_rect(&region_available, 0, 0,
                           rtgui_graphic_driver_get_default()->width,
                           rtgui_graphic_driver_get_default()->height);

    /* from top to bottom. */
    top = _rtgui_topwin_get_topmost_window_shown(WINTITLE_ONTOP);
    /* 0 is normal layer */
    if (top == RT_NULL)
        top = _rtgui_topwin_get_topmost_window_shown(0);
    if (top == RT_NULL)
        top = _rtgui_topwin_get_topmost_window_shown(WINTITLE_ONBTM);

    while (top != RT_NULL)
    {
        /* clip the topwin */
        _rtgui_topwin_clip_to_region(&region_available, top);
#if 0
        /* debug window clipping */
        rt_kprintf("clip %s ", top->wid->title);
        rtgui_region_dump(&region_available);
        rt_kprintf("\n");
#endif

        /* update available region */
        if (top->title != RT_NULL)
            rtgui_region_subtract_rect(&region_available, &region_available, &RTGUI_WIDGET(top->title)->extent);
        else
            rtgui_region_subtract_rect(&region_available, &region_available, &top->extent);

        /* send clip event to destination window */
        eclip.wid = top->wid;
        rtgui_send(top->tid, &(eclip.parent), sizeof(struct rtgui_event_clip_info));

        /* move to next sibling tree */
        if (top->parent == RT_NULL)
            if (top->list.next != &_rtgui_topwin_list &&
                    get_topwin_from_list(top->list.next)->flag & WINTITLE_SHOWN)
                top = _rtgui_topwin_get_topmost_child_shown(get_topwin_from_list(top->list.next));
            else
                break;
        /* move to next slibing topwin */
        else if (top->list.next != &top->parent->child_list &&
                 get_topwin_from_list(top->list.next)->flag & WINTITLE_SHOWN)
            top = _rtgui_topwin_get_topmost_child_shown(get_topwin_from_list(top->list.next));
        /* level up */
        else
            top = top->parent;
    }
}

static void _rtgui_topwin_redraw_tree(struct rtgui_dlist_node *list,
                                      struct rtgui_rect *rect,
                                      struct rtgui_event_paint *epaint)
{
    struct rtgui_dlist_node *node;

    RT_ASSERT(list != RT_NULL);
    RT_ASSERT(rect != RT_NULL);
    RT_ASSERT(epaint != RT_NULL);

    /* skip the hidden windows */
    rtgui_dlist_foreach(node, list, prev)
    {
        if (get_topwin_from_list(node)->flag & WINTITLE_SHOWN)
            break;
    }

    for (; node != list; node = node->prev)
    {
        struct rtgui_topwin *topwin;

        topwin = get_topwin_from_list(node);

        //FIXME: intersect with clip?
        if (rtgui_rect_is_intersect(rect, &(topwin->extent)) == RT_EOK)
        {
            epaint->wid = topwin->wid;
            rtgui_send(topwin->tid, &(epaint->parent), sizeof(*epaint));

            /* draw title */
            if (topwin->title != RT_NULL)
            {
                rtgui_theme_draw_win(topwin);
            }
        }

        _rtgui_topwin_redraw_tree(&topwin->child_list, rect, epaint);
    }
}

static void rtgui_topwin_redraw(struct rtgui_rect *rect)
{
    struct rtgui_event_paint epaint;
    RTGUI_EVENT_PAINT_INIT(&epaint);
    epaint.wid = RT_NULL;

    _rtgui_topwin_redraw_tree(&_rtgui_topwin_list, rect, &epaint);
}

/* a window enter modal mode will modal all the sibling window and parent
 * window all along to the root window(which parent is RT_NULL or the desktop
 * window if there is). If a root window modals, there is nothing to do here.*/
rt_err_t rtgui_topwin_modal_enter(struct rtgui_event_win_modal_enter *event)
{
    struct rtgui_topwin *topwin, *parent_top;
    struct rtgui_dlist_node *node;

    topwin = rtgui_topwin_search_in_list(event->wid, &_rtgui_topwin_list);

    if (topwin == RT_NULL)
        return -RT_ERROR;

    if (IS_ROOT_WIN(topwin))
        return RT_EOK;

    parent_top = topwin->parent;

    /* modal window should be on top already */
    RT_ASSERT(get_topwin_from_list(parent_top->child_list.next) == topwin);

    while (!IS_ROOT_WIN(parent_top))
    {
        rtgui_dlist_foreach(node, &parent_top->child_list, next)
        get_topwin_from_list(node)->flag |= WINTITLE_MODALED;
        parent_top->flag |= WINTITLE_MODALED;

        parent_top = parent_top->parent;
    }
    /* mark root window as modaled */
    parent_top->flag |= WINTITLE_MODALED;

    topwin->flag &= ~WINTITLE_MODALED;
    topwin->flag |= WINTITLE_MODALING;

    return RT_EOK;
}

void rtgui_topwin_title_onmouse(struct rtgui_topwin *win, struct rtgui_event_mouse *event)
{
    rtgui_rect_t rect;

    /* let window to process this mouse event */
    if (rtgui_rect_contains_point(&win->extent, event->x, event->y) == RT_EOK)
    {
        /* send mouse event to thread */
        rtgui_send(win->tid, &(event->parent), sizeof(struct rtgui_event_mouse));
        return;
    }

    /* get close button rect (device value) */
    rect.x1 = RTGUI_WIDGET(win->title)->extent.x2 - WINTITLE_BORDER_SIZE - WINTITLE_CB_WIDTH - 3;
    rect.y1 = RTGUI_WIDGET(win->title)->extent.y1 + WINTITLE_BORDER_SIZE + 3;
    rect.x2 = rect.x1 + WINTITLE_CB_WIDTH;
    rect.y2 = rect.y1 + WINTITLE_CB_HEIGHT;

    if (event->button & RTGUI_MOUSE_BUTTON_LEFT)
    {
        if (event->button & RTGUI_MOUSE_BUTTON_DOWN)
        {
            if (rtgui_rect_contains_point(&rect, event->x, event->y) == RT_EOK)
            {
                win->flag |= WINTITLE_CB_PRESSED;
                rtgui_theme_draw_win(win);
            }
#ifdef RTGUI_USING_WINMOVE
            else
            {
                /* maybe move window */
                rtgui_winrect_set(win);
            }
#endif
        }
        else if (win->flag & WINTITLE_CB_PRESSED && event->button & RTGUI_MOUSE_BUTTON_UP)
        {
            if (rtgui_rect_contains_point(&rect, event->x, event->y) == RT_EOK)
            {
                struct rtgui_event_win event;

                win->flag &= ~WINTITLE_CB_PRESSED;
                rtgui_theme_draw_win(win);

                /* send close event to window */
                RTGUI_EVENT_WIN_CLOSE_INIT(&event);
                event.wid = win->wid;
                rtgui_send(win->tid, &(event.parent), sizeof(struct rtgui_event_win));
            }
        }
    }
}

void rtgui_topwin_append_monitor_rect(struct rtgui_win *wid, rtgui_rect_t *rect)
{
    struct rtgui_topwin *win;

    /* parameters check */
    if (wid == RT_NULL || rect == RT_NULL) return;

    /* find topwin */
    win = rtgui_topwin_search_in_list(wid, &_rtgui_topwin_list);
    if (win == RT_NULL)
        return;

    /* append rect to top window monitor rect list */
    rtgui_mouse_monitor_append(&(win->monitor_list), rect);
}

void rtgui_topwin_remove_monitor_rect(struct rtgui_win *wid, rtgui_rect_t *rect)
{
    struct rtgui_topwin *win;

    /* parameters check */
    if (wid == RT_NULL || rect == RT_NULL)
        return;

    /* find topwin */
    win = rtgui_topwin_search_in_list(wid, &_rtgui_topwin_list);
    if (win == RT_NULL)
        return;

    /* remove rect from top window monitor rect list */
    rtgui_mouse_monitor_remove(&(win->monitor_list), rect);
}

static void _rtgui_topwin_dump(struct rtgui_topwin *topwin)
{
    rt_kprintf("0x%p:%s,0x%x", topwin, topwin->wid->title, topwin->flag);
}

static void _rtgui_topwin_dump_tree(struct rtgui_topwin *topwin)
{
    struct rtgui_dlist_node *node;

    _rtgui_topwin_dump(topwin);

    rt_kprintf("(");
    rtgui_dlist_foreach(node, &topwin->child_list, next)
    {
        _rtgui_topwin_dump_tree(get_topwin_from_list(node));
    }
    rt_kprintf(")");
}

void rtgui_topwin_dump_tree(void)
{
    struct rtgui_dlist_node *node;

    rtgui_dlist_foreach(node, &_rtgui_topwin_list, next)
    {
        _rtgui_topwin_dump_tree(get_topwin_from_list(node));
        rt_kprintf("\n");
    }
}

#ifdef RT_USING_FINSH
#include <finsh.h>
void dump_tree()
{
    rtgui_topwin_dump_tree();
}
FINSH_FUNCTION_EXPORT(dump_tree, dump rtgui topwin tree)
#endif