awesome/client.c

/*  
 * client.c - client management 
 *  
 * Copyright © 2007 Julien Danjou <julien@danjou.info> 
 * 
 * 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. 
 * 
 * You should have received a copy of the GNU General Public License along 
 * with this program; if not, write to the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 
 * 
 */

#include <stdio.h>
#include <X11/Xatom.h>
#include <X11/Xutil.h>
#include <X11/extensions/shape.h>

#include "screen.h"
#include "awesome.h"
#include "layout.h"
#include "tag.h"
#include "util.h"
#include "statusbar.h"

#include "layouts/floating.h"

/* extern */
extern Client *clients, *sel, *stack;   /* global client list and stack */

/** Attach client stack to clients stacks
 * \param c the client
 */ 
static inline void
attachstack(Client * c)
{
    c->snext = stack;
    stack = c;
}

/** Detach client from stack
 * \param c the client
 */
static inline void
detachstack(Client * c)
{
    Client **tc;

    for(tc = &stack; *tc && *tc != c; tc = &(*tc)->snext);
    *tc = c->snext;
}

/** Grab or ungrab buttons when a client is focused
 * \param c client
 * \param focused True if client is focused
 * \param modkey Mod key mask
 * \param numlockmask Numlock mask
 */
static void
grabbuttons(Client * c, Bool focused, KeySym modkey, unsigned int numlockmask)
{
    XUngrabButton(c->display, AnyButton, AnyModifier, c->win);

    if(focused)
    {
        XGrabButton(c->display, Button1, modkey, c->win, False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button1, modkey | LockMask, c->win, False,
                    BUTTONMASK, GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button1, modkey | numlockmask, c->win, False,
                    BUTTONMASK, GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button1, modkey | numlockmask | LockMask,
                    c->win, False, BUTTONMASK, GrabModeAsync, GrabModeSync, None, None);

        XGrabButton(c->display, Button2, modkey, c->win, False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button2, modkey | LockMask, c->win, False,
                    BUTTONMASK, GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button2, modkey | numlockmask, c->win, False,
                    BUTTONMASK, GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button2, modkey | numlockmask | LockMask,
                    c->win, False, BUTTONMASK, GrabModeAsync, GrabModeSync, None, None);

        XGrabButton(c->display, Button3, modkey, c->win, False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button3, modkey | LockMask, c->win, False,
                    BUTTONMASK, GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button3, modkey | numlockmask, c->win, False,
                    BUTTONMASK, GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button3, modkey | numlockmask | LockMask,
                    c->win, False, BUTTONMASK, GrabModeAsync, GrabModeSync, None, None);

        XUngrabButton(c->display, AnyButton, AnyModifier, RootWindow(c->display, c->screen));
    }
    else
    {
        XGrabButton(c->display, AnyButton, AnyModifier, c->win, False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button4, NoSymbol, RootWindow(c->display, c->screen), False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button4, LockMask, RootWindow(c->display, c->screen), False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button4, numlockmask, RootWindow(c->display, c->screen), False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button4, numlockmask | LockMask, RootWindow(c->display, c->screen), False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);

        XGrabButton(c->display, Button5, NoSymbol, RootWindow(c->display, c->screen), False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button5, LockMask, RootWindow(c->display, c->screen), False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button5, numlockmask, RootWindow(c->display, c->screen), False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);
        XGrabButton(c->display, Button5, numlockmask | LockMask, RootWindow(c->display, c->screen), False, BUTTONMASK,
                    GrabModeAsync, GrabModeSync, None, None);

    }
}

/** Check if client supports protocol WM_DELETE_WINDOW
 * \param c the client
 * \return True if client has WM_DELETE_WINDOW
 */
static Bool
isprotodel(Client * c)
{
    int i, n;
    Atom *protocols;
    Bool ret = False;

    if(XGetWMProtocols(c->display, c->win, &protocols, &n))
    {
        for(i = 0; !ret && i < n; i++)
            if(protocols[i] == XInternAtom(c->display, "WM_DELETE_WINDOW", False))
                ret = True;
        XFree(protocols);
    }
    return ret;
}

/** Set client WM_STATE property
 * \param c the client
 * \param state no idea
 */
static void
setclientstate(Client * c, long state)
{
    long data[] = { state, None };

    XChangeProperty(c->display, c->win, XInternAtom(c->display, "WM_STATE", False),
                    XInternAtom(c->display, "WM_STATE", False),  32,
                    PropModeReplace, (unsigned char *) data, 2);
}

/** Set client transparency using composite
 * \param c client
 * \param opacity opacity percentage
 */
static void
setclienttrans(Client *c, double opacity)
{
    unsigned int real_opacity = 0xffffffff;

    if(opacity >= 0 && opacity <= 100)
    {
        real_opacity = ((opacity / 100.0) * 0xffffffff);
        XChangeProperty(c->display, c->win,
                        XInternAtom(c->display, "_NET_WM_WINDOW_OPACITY", False),
                        XA_CARDINAL, 32, PropModeReplace, (unsigned char *) &real_opacity, 1L);
    }
    else
        XDeleteProperty(c->display, c->win, XInternAtom(c->display, "_NET_WM_WINDOW_OPACITY", False));

    XSync(c->display, False);
}

/** Attach client to the beginning of the clients stack
 * \param c the client
 */
inline void
attach(Client * c)
{
    if(clients)
        clients->prev = c;
    c->next = clients;
    clients = c;
}

inline void
updatetitle(Client * c)
{
    if(!xgettextprop(c->display, c->win, XInternAtom(c->display, "_NET_WM_NAME", False), c->name, sizeof c->name))
        xgettextprop(c->display, c->win, XInternAtom(c->display, "WM_NAME", False), c->name, sizeof c->name);
}

/** Ban client and unmapped it
 * \param c the client
 */
void
ban(Client * c)
{
    XUnmapWindow(c->display, c->win);
    setclientstate(c, IconicState);
    c->isbanned = True;
    c->unmapped = True;
}

/** Configure client
 * \param c the client
 */
void
configure(Client * c)
{
    XConfigureEvent ce;

    ce.type = ConfigureNotify;
    ce.display = c->display;
    ce.event = c->win;
    ce.window = c->win;
    ce.x = c->x;
    ce.y = c->y;
    ce.width = c->w;
    ce.height = c->h;
    ce.border_width = c->border;
    ce.above = None;
    ce.override_redirect = False;
    XSendEvent(c->display, c->win, False, StructureNotifyMask, (XEvent *) & ce);
}

void
detach(Client * c)
{
    if(c->prev)
        c->prev->next = c->next;
    if(c->next)
        c->next->prev = c->prev;
    if(c == clients)
        clients = c->next;
    c->next = c->prev = NULL;
}

/** Give focus to client, or to first client if c is NULL
 * \param disp Display ref
 * \param drawcontext drawcontext ref
 * \param c client
 * \param selscreen True if current screen is selected
 * \param awesomeconf awesome config
 */
void
focus(Display *disp, DC *drawcontext, Client * c, Bool selscreen, awesome_config *awesomeconf)
{
    /* if c is NULL or invisible, take next client in the stack */
    if((!c && selscreen) || (c && !isvisible(c, awesomeconf->screen, awesomeconf->selected_tags, awesomeconf->ntags)))
        for(c = stack; c && !isvisible(c, awesomeconf->screen, awesomeconf->selected_tags, awesomeconf->ntags); c = c->snext);
    
    /* if a client was selected but it's not the current client, unfocus it */
    if(sel && sel != c)
    {
        grabbuttons(sel, False, awesomeconf->modkey, awesomeconf->numlockmask);
        XSetWindowBorder(sel->display, sel->win, drawcontext->norm[ColBorder]);
        setclienttrans(sel, awesomeconf->opacity_unfocused);
    }
    if(c)
    {
        detachstack(c);
        attachstack(c);
        grabbuttons(c, True, awesomeconf->modkey, awesomeconf->numlockmask);
    }
    if(!selscreen)
        return;
    sel = c;
    drawstatusbar(disp, awesomeconf->screen, drawcontext, awesomeconf);
    if(sel)
    {
        XSetWindowBorder(sel->display, sel->win, drawcontext->sel[ColBorder]);
        XSetInputFocus(sel->display, sel->win, RevertToPointerRoot, CurrentTime);
        for(c = stack; c; c = c->snext)
            if(c != sel)
                setclienttrans(c, awesomeconf->opacity_unfocused);
        setclienttrans(sel, -1);
    }
    else
        XSetInputFocus(disp, RootWindow(disp, awesomeconf->screen), RevertToPointerRoot, CurrentTime);
}

/** Kill selected client
 * \param disp Display ref
 * \param drawcontext Drawcontext ref
 * \param awesomeconf awesome config
 * \param arg unused
 * \ingroup ui_callback
 */
void
uicb_killclient(Display *disp __attribute__ ((unused)),
                DC *drawcontext __attribute__ ((unused)),
                awesome_config *awesomeconf __attribute__ ((unused)),
                const char *arg __attribute__ ((unused)))
{
    XEvent ev;

    if(!sel)
        return;
    if(isprotodel(sel))
    {
        ev.type = ClientMessage;
        ev.xclient.window = sel->win;
        ev.xclient.message_type = XInternAtom(disp, "WM_PROTOCOLS", False);
        ev.xclient.format = 32;
        ev.xclient.data.l[0] = XInternAtom(disp, "WM_DELETE_WINDOW", False);
        ev.xclient.data.l[1] = CurrentTime;
        XSendEvent(sel->display, sel->win, False, NoEventMask, &ev);
    }
    else
        XKillClient(sel->display, sel->win);
}


/** Load windows properties, restoring client's tag
 * and floating state before awesome was restarted if any
 * \todo this may bug if number of tags is != than before
 * \param c Client ref
 * \param ntags tags number
 */
static Bool
loadprops(Client * c, int ntags)
{
    int i;
    char *prop;
    Bool result = False;

    prop = p_new(char, ntags + 2);

    if(xgettextprop(c->display, c->win, AWESOMEPROPS_ATOM(c->display), prop, ntags + 2))
    {
        for(i = 0; i < ntags && prop[i]; i++)
            if((c->tags[i] = prop[i] == '1'))
                result = True;
        if(i <= ntags && prop[i])
            c->isfloating = prop[i] == '1';
    }

    p_delete(&prop);

    return result;
}

/** Manage a new client
 * \param disp Display ref
 * \param drawcontext Drawcontext ref
 * \param w The window
 * \param wa Window attributes
 * \param awesomeconf awesome config
 */
void
manage(Display * disp, DC *drawcontext, Window w, XWindowAttributes * wa, awesome_config *awesomeconf)
{
    int i;
    Client *c, *t = NULL;
    Window trans;
    Status rettrans;
    XWindowChanges wc;

    c = p_new(Client, 1);
    c->tags = p_new(Bool, awesomeconf->ntags);
    c->win = w;
    c->ftview = True;
    c->x = c->rw = wa->x;
    c->y = c->ry = wa->y;
    c->w = c->rw = wa->width;
    c->h = c->rh = wa->height;
    c->oldborder = wa->border_width;
    c->display = disp;
    c->screen = awesomeconf->screen;
    if(c->w == DisplayWidth(disp, c->screen)
       && c->h == DisplayHeight(disp, c->screen))
    {
        c->x = 0;
        c->y = 0;
        c->border = wa->border_width;
    }
    else
    {
        ScreenInfo *si = get_display_info(disp, c->screen, awesomeconf->statusbar);

        if(c->x + c->w + 2 * c->border > si->x_org + si->width)
            c->x = c->rx = si->x_org + si->width - c->w - 2 * c->border;
        if(c->y + c->h + 2 * c->border > si->y_org + si->height)
            c->y = c->ry = si->y_org + si->height - c->h - 2 * c->border;
        if(c->x < si->x_org)
            c->x = c->rx = si->x_org;
        if(c->y < si->y_org)
            c->y = c->ry = si->y_org;
        c->border = awesomeconf->borderpx;
        XFree(si);
    }
    wc.border_width = c->border;
    XConfigureWindow(disp, w, CWBorderWidth, &wc);
    XSetWindowBorder(disp, w, drawcontext->norm[ColBorder]);
    configure(c);               /* propagates border_width, if size doesn't change */
    updatesizehints(c);
    XSelectInput(disp, w, StructureNotifyMask | PropertyChangeMask | EnterWindowMask);
    if(awesomeconf->have_shape)
    {
        XShapeSelectInput(disp, w, ShapeNotifyMask);
        set_shape(c);
    }
    grabbuttons(c, False, awesomeconf->modkey, awesomeconf->numlockmask);
    updatetitle(c);
    if((rettrans = XGetTransientForHint(disp, w, &trans) == Success))
        for(t = clients; t && t->win != trans; t = t->next);
    if(t)
        for(i = 0; i < awesomeconf->ntags; i++)
            c->tags[i] = t->tags[i];
    if(!loadprops(c, awesomeconf->ntags))
        applyrules(c, awesomeconf);
    if(!c->isfloating)
        c->isfloating = (rettrans == Success) || c->isfixed;
    saveprops(c, awesomeconf->ntags);
    attach(c);
    attachstack(c);
    XMoveResizeWindow(disp, c->win, c->x, c->y, c->w, c->h);     /* some windows require this */
    c->isbanned = True;
    arrange(disp, drawcontext, awesomeconf);
}

void
resize(Client * c, int x, int y, int w, int h, Bool sizehints)
{
    double dx, dy, max, min, ratio;
    XWindowChanges wc;

    if(sizehints)
    {
        if(c->minay > 0 && c->maxay > 0 && (h - c->baseh) > 0 && (w - c->basew) > 0)
        {
            dx = (double) (w - c->basew);
            dy = (double) (h - c->baseh);
            min = (double) (c->minax) / (double) (c->minay);
            max = (double) (c->maxax) / (double) (c->maxay);
            ratio = dx / dy;
            if(max > 0 && min > 0 && ratio > 0)
            {
                if(ratio < min)
                {
                    dy = (dx * min + dy) / (min * min + 1);
                    dx = dy * min;
                    w = (int) dx + c->basew;
                    h = (int) dy + c->baseh;
                }
                else if(ratio > max)
                {
                    dy = (dx * min + dy) / (max * max + 1);
                    dx = dy * min;
                    w = (int) dx + c->basew;
                    h = (int) dy + c->baseh;
                }
            }
        }
        if(c->minw && w < c->minw)
            w = c->minw;
        if(c->minh && h < c->minh)
            h = c->minh;
        if(c->maxw && w > c->maxw)
            w = c->maxw;
        if(c->maxh && h > c->maxh)
            h = c->maxh;
        if(c->incw)
            w -= (w - c->basew) % c->incw;
        if(c->inch)
            h -= (h - c->baseh) % c->inch;
    }
    if(w <= 0 || h <= 0)
        return;
    /* offscreen appearance fixes */
    if(x > DisplayWidth(c->display, c->screen))
        x = DisplayWidth(c->display, c->screen) - w - 2 * c->border;
    if(y > DisplayHeight(c->display, c->screen))
        y = DisplayHeight(c->display, c->screen) - h - 2 * c->border;
    if(x + w + 2 * c->border < 0)
        x = 0;
    if(y + h + 2 * c->border < 0)
        y = 0;
    if(c->x != x || c->y != y || c->w != w || c->h != h)
    {
        c->x = wc.x = x;
        c->y = wc.y = y;
        c->w = wc.width = w;
        c->h = wc.height = h;
        wc.border_width = c->border;
        XConfigureWindow(c->display, c->win, CWX | CWY | CWWidth | CWHeight | CWBorderWidth, &wc);
        configure(c);
        XSync(c->display, False);
    }
}

void
uicb_moveresize(Display *disp __attribute__ ((unused)),
                DC *drawcontext __attribute__ ((unused)),
                awesome_config *awesomeconf,
                const char *arg)
{
    int x, y, w, h, nx, ny, nw, nh, ox, oy, ow, oh;
    char xabs, yabs, wabs, habs;
    int mx, my, dx, dy, nmx, nmy;
    unsigned int dui;
    Window dummy;

    if(!IS_ARRANGE(layout_floating))
        if(!sel || !sel->isfloating || sel->isfixed || !arg)
            return;
    if(sscanf(arg, "%d%c %d%c %d%c %d%c", &x, &xabs, &y, &yabs, &w, &wabs, &h, &habs) != 8)
        return;
    nx = xabs == 'x' ? sel->x + x : x;
    ny = yabs == 'y' ? sel->y + y : y;
    nw = wabs == 'w' ? sel->w + w : w;
    nh = habs == 'h' ? sel->h + h : h;

    ox = sel->x;
    oy = sel->y;
    ow = sel->w;
    oh = sel->h;

    Bool xqp = XQueryPointer(sel->display, RootWindow(sel->display, sel->screen), &dummy, &dummy, &mx, &my, &dx, &dy, &dui);
    resize(sel, nx, ny, nw, nh, True);
    if (xqp && ox <= mx && (ox + ow) >= mx && oy <= my && (oy + oh) >= my)
    {
        nmx = mx-ox+sel->w-ow-1 < 0 ? 0 : mx-ox+sel->w-ow-1;
        nmy = my-oy+sel->h-oh-1 < 0 ? 0 : my-oy+sel->h-oh-1;
        XWarpPointer(sel->display, None, sel->win, 0, 0, 0, 0, nmx, nmy);
    }
}

void
saveprops(Client * c, int ntags)
{
    int i;
    char *prop;

    prop = p_new(char, ntags + 2);

    for(i = 0; i < ntags; i++)
        prop[i] = c->tags[i] ? '1' : '0';

    if(i <= ntags)
        prop[i] = c->isfloating ? '1' : '0';

    prop[++i] = '\0';

    XChangeProperty(c->display, c->win, AWESOMEPROPS_ATOM(c->display), XA_STRING, 8,
                    PropModeReplace, (unsigned char *) prop, i);

    p_delete(&prop);
}

void
unban(Client * c)
{
    XMapWindow(c->display, c->win);
    setclientstate(c, NormalState);
    c->isbanned = False;
    c->unmapped = False;
}

void
unmanage(Client * c, DC *drawcontext, long state, awesome_config *awesomeconf)
{
    XWindowChanges wc;

    c->unmapped = True;
    wc.border_width = c->oldborder;
    /* The server grab construct avoids race conditions. */
    XGrabServer(c->display);
    XConfigureWindow(c->display, c->win, CWBorderWidth, &wc);  /* restore border */
    detach(c);
    detachstack(c);
    if(sel == c)
        focus(c->display, drawcontext, NULL, True, awesomeconf);
    XUngrabButton(c->display, AnyButton, AnyModifier, c->win);
    setclientstate(c, state);
    XSync(c->display, False);
    XSetErrorHandler(xerror);
    XUngrabServer(c->display);
    if(state != NormalState)
        arrange(c->display, drawcontext, awesomeconf);
    p_delete(&c->tags);
    p_delete(&c);
}

void
updatesizehints(Client * c)
{
    long msize;
    XSizeHints size;

    if(!XGetWMNormalHints(c->display, c->win, &size, &msize) || !size.flags)
        size.flags = PSize;
    c->flags = size.flags;
    if(c->flags & PBaseSize)
    {
        c->basew = size.base_width;
        c->baseh = size.base_height;
    }
    else if(c->flags & PMinSize)
    {
        c->basew = size.min_width;
        c->baseh = size.min_height;
    }
    else
        c->basew = c->baseh = 0;
    if(c->flags & PResizeInc)
    {
        c->incw = size.width_inc;
        c->inch = size.height_inc;
    }
    else
        c->incw = c->inch = 0;

    if(c->flags & PMaxSize)
    {
        c->maxw = size.max_width;
        c->maxh = size.max_height;
    }
    else
        c->maxw = c->maxh = 0;

    if(c->flags & PMinSize)
    {
        c->minw = size.min_width;
        c->minh = size.min_height;
    }
    else if(c->flags & PBaseSize)
    {
        c->minw = size.base_width;
        c->minh = size.base_height;
    }
    else
        c->minw = c->minh = 0;

    if(c->flags & PAspect)
    {
        c->minax = size.min_aspect.x;
        c->maxax = size.max_aspect.x;
        c->minay = size.min_aspect.y;
        c->maxay = size.max_aspect.y;
    }
    else
        c->minax = c->maxax = c->minay = c->maxay = 0;

    c->isfixed = (c->maxw && c->minw && c->maxh && c->minh
                  && c->maxw == c->minw && c->maxh == c->minh);
}

void
set_shape(Client *c)
{
    int bounding_shaped;
    int i, b;  unsigned int u;  /* dummies */
    /* Logic to decide if we have a shaped window cribbed from fvwm-2.5.10. */
    if (XShapeQueryExtents(c->display, c->win, &bounding_shaped, &i, &i,
                           &u, &u, &b, &i, &i, &u, &u) && bounding_shaped)
        XShapeCombineShape(c->display, RootWindow(c->display, c->screen), ShapeBounding, 0, 0, c->win, ShapeBounding, ShapeSet);
}

/** Set selected client transparency
 * \param disp Display ref
 * \param drawcontext Drawcontext ref
 * \param awesomeconf awesome config
 * \param arg unused arg
 * \ingroup ui_callback
 */
void
uicb_settrans(Display *disp __attribute__ ((unused)),
              DC *drawcontext __attribute__ ((unused)),
              awesome_config *awesomeconf __attribute__ ((unused)),
              const char *arg)
{
    double delta = 100.0, current_opacity = 0.0;
    unsigned char *data;
    Atom actual;
    int format;
    unsigned long n, left;
    unsigned int current_opacity_raw = 0;
    int set_prop = 0;

    if(!sel)
        return;

    XGetWindowProperty(sel->display, sel->win, XInternAtom(sel->display, "_NET_WM_WINDOW_OPACITY", False),
                       0L, 1L, False, XA_CARDINAL, &actual, &format, &n, &left,
                       (unsigned char **) &data);
    if(data)
    {
        memcpy(&current_opacity_raw, data, sizeof(unsigned int));
        XFree(data);
        current_opacity = (current_opacity_raw * 100.0) / 0xffffffff;
    }
    else
        set_prop = 1;

    delta = compute_new_value_from_arg(arg, current_opacity);

    if(delta <= 0.0)
        delta = 0.0;
    else if(delta > 100.0)
    {
        delta = 100.0;
        set_prop = 1;
    }

    if(delta == 100.0 && !set_prop)
        setclienttrans(sel, -1);
    else
        setclienttrans(sel, delta);
}


/** Set borrder size
 * \param disp Display ref
 * \param drawcontext Drawcontext ref
 * \param awesomeconf awesome config
 * \param arg X, +X or -X
 * \ingroup ui_callback
 */
void
uicb_setborder(Display *disp __attribute__ ((unused)),
               DC *drawcontext __attribute__ ((unused)),
               awesome_config *awesomeconf,
               const char *arg)
{
    if(!arg)
        return;

    if((awesomeconf->borderpx = (int) compute_new_value_from_arg(arg, (double) awesomeconf->borderpx)) < 0)
        awesomeconf->borderpx = 0;
}