/* -*- indent-tabs-mode: nil; tab-width: 4; c-basic-offset: 4; -*-

   focus.c for the Openbox window manager
   Copyright (c) 2006        Mikael Magnusson
   Copyright (c) 2003-2007   Dana Jansens

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   See the COPYING file for a copy of the GNU General Public License.
*/

#include "debug.h"
#include "event.h"
#include "openbox.h"
#include "grab.h"
#include "client.h"
#include "config.h"
#include "focus_cycle.h"
#include "screen.h"
#include "prop.h"
#include "keyboard.h"
#include "focus.h"
#include "stacking.h"

#include <X11/Xlib.h>
#include <glib.h>

#define FOCUS_INDICATOR_WIDTH 6

ObClient *focus_client = NULL;
GList *focus_order = NULL;

void focus_startup(gboolean reconfig)
{
    if (reconfig) return;

    /* start with nothing focused */
    focus_nothing();
}

void focus_shutdown(gboolean reconfig)
{
    if (reconfig) return;

    /* reset focus to root */
    XSetInputFocus(ob_display, PointerRoot, RevertToNone, CurrentTime);
}

static void push_to_top(ObClient *client)
{
    focus_order = g_list_remove(focus_order, client);
    focus_order = g_list_prepend(focus_order, client);
}

void focus_set_client(ObClient *client)
{
    Window active;

    ob_debug_type(OB_DEBUG_FOCUS,
                  "focus_set_client 0x%lx\n", client ? client->window : 0);

    if (focus_client == client)
        return;

    /* uninstall the old colormap, and install the new one */
    screen_install_colormap(focus_client, FALSE);
    screen_install_colormap(client, TRUE);

    /* in the middle of cycling..? kill it. */
    focus_cycle_stop(focus_client);
    focus_cycle_stop(client);

    focus_client = client;

    if (client != NULL) {
        /* move to the top of the list */
        push_to_top(client);
        /* remove hiliting from the window when it gets focused */
        client_hilite(client, FALSE);
    }

    /* set the NET_ACTIVE_WINDOW hint, but preserve it on shutdown */
    if (ob_state() != OB_STATE_EXITING) {
        active = client ? client->window : None;
        PROP_SET32(RootWindow(ob_display, ob_screen),
                   net_active_window, window, active);
    }
}

static ObClient* focus_fallback_target(gboolean allow_refocus,
                                       gboolean allow_pointer,
                                       ObClient *old)
{
    GList *it;
    ObClient *c;

    ob_debug_type(OB_DEBUG_FOCUS, "trying pointer stuff\n");
    if (allow_pointer && config_focus_follow)
        if ((c = client_under_pointer()) &&
            (allow_refocus || c != old) &&
            (client_normal(c) &&
             client_focus(c)))
        {
            ob_debug_type(OB_DEBUG_FOCUS, "found in pointer stuff\n");
            return c;
        }

    ob_debug_type(OB_DEBUG_FOCUS, "trying the focus order\n");
    for (it = focus_order; it; it = g_list_next(it)) {
        c = it->data;
        /* fallback focus to a window if:
           1. it is on the current desktop. this ignores omnipresent
           windows, which are problematic in their own rite.
           2. it is a normal type window, don't fall back onto a dock or
           a splashscreen or a desktop window (save the desktop as a
           backup fallback though)
        */
        if (c->desktop == screen_desktop &&
            client_normal(c) &&
            (allow_refocus || c != old) &&
            client_focus(c))
        {
            ob_debug_type(OB_DEBUG_FOCUS, "found in focus order\n");
            return c;
        }
    }

    ob_debug_type(OB_DEBUG_FOCUS, "trying a desktop window\n");
    for (it = focus_order; it; it = g_list_next(it)) {
        c = it->data;
        /* fallback focus to a window if:
           1. it is on the current desktop. this ignores omnipresent
           windows, which are problematic in their own rite.
           2. it is a normal type window, don't fall back onto a dock or
           a splashscreen or a desktop window (save the desktop as a
           backup fallback though)
        */
        if (c->type == OB_CLIENT_TYPE_DESKTOP &&
            (allow_refocus || c != old) &&
            client_focus(c))
        {
            ob_debug_type(OB_DEBUG_FOCUS, "found a desktop window\n");
            return c;
        }
    }

    return NULL;
}

ObClient* focus_fallback(gboolean allow_refocus, gboolean allow_pointer)
{
    ObClient *new;
    ObClient *old = focus_client;

    /* unfocus any focused clients.. they can be focused by Pointer events
       and such, and then when we try focus them, we won't get a FocusIn
       event at all for them. */
    focus_nothing();

    new = focus_fallback_target(allow_refocus, allow_pointer, old);
    /* get what was really focused */
    if (new) new = client_focus_target(new);

    return new;
}

void focus_nothing()
{
    /* Install our own colormap */
    if (focus_client != NULL) {
        screen_install_colormap(focus_client, FALSE);
        screen_install_colormap(NULL, TRUE);
    }

    /* nothing is focused, update the colormap and _the root property_ */
    focus_set_client(NULL);

    /* if there is a grab going on, then we need to cancel it. if we move
       focus during the grab, applications will get NotifyWhileGrabbed events
       and ignore them !

       actions should not rely on being able to move focus during an
       interactive grab.
    */
    event_cancel_all_key_grabs();

    /* when nothing will be focused, send focus to the backup target */
    XSetInputFocus(ob_display, screen_support_win, RevertToPointerRoot,
                   event_curtime);
}

void focus_order_add_new(ObClient *c)
{
    if (c->iconic)
        focus_order_to_top(c);
    else {
        g_assert(!g_list_find(focus_order, c));
        /* if there are any iconic windows, put this above them in the order,
           but if there are not, then put it under the currently focused one */
        if (focus_order && ((ObClient*)focus_order->data)->iconic)
            focus_order = g_list_insert(focus_order, c, 0);
        else
            focus_order = g_list_insert(focus_order, c, 1);
    }

    /* in the middle of cycling..? kill it. */
    focus_cycle_stop(c);
}

void focus_order_remove(ObClient *c)
{
    focus_order = g_list_remove(focus_order, c);

    /* in the middle of cycling..? kill it. */
    focus_cycle_stop(c);
}

void focus_order_to_top(ObClient *c)
{
    focus_order = g_list_remove(focus_order, c);
    if (!c->iconic) {
        focus_order = g_list_prepend(focus_order, c);
    } else {
        GList *it;

        /* insert before first iconic window */
        for (it = focus_order;
             it && !((ObClient*)it->data)->iconic; it = g_list_next(it));
        focus_order = g_list_insert_before(focus_order, it, c);
    }
}

void focus_order_to_bottom(ObClient *c)
{
    focus_order = g_list_remove(focus_order, c);
    if (c->iconic) {
        focus_order = g_list_append(focus_order, c);
    } else {
        GList *it;

        /* insert before first iconic window */
        for (it = focus_order;
             it && !((ObClient*)it->data)->iconic; it = g_list_next(it));
        focus_order = g_list_insert_before(focus_order, it, c);
    }
}

ObClient *focus_order_find_first(guint desktop)
{
    GList *it;
    for (it = focus_order; it; it = g_list_next(it)) {
        ObClient *c = it->data;
        if (c->desktop == desktop || c->desktop == DESKTOP_ALL)
            return c;
    }
    return NULL;
}