rofi/source/textbox.c

/**
 *   MIT/X11 License
 *   Copyright (c) 2012 Sean Pringle <sean.pringle@gmail.com>
 *   Modified  (c) 2013-2015 Qball Cow <qball@gmpclient.org>
 *
 *   Permission is hereby granted, free of charge, to any person obtaining
 *   a copy of this software and associated documentation files (the
 *   "Software"), to deal in the Software without restriction, including
 *   without limitation the rights to use, copy, modify, merge, publish,
 *   distribute, sublicense, and/or sell copies of the Software, and to
 *   permit persons to whom the Software is furnished to do so, subject to
 *   the following conditions:
 *
 *   The above copyright notice and this permission notice shall be
 *   included in all copies or substantial portions of the Software.
 *
 *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 *   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 *   IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 *   CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 *   TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 *   SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <config.h>
#include <X11/X.h>
#include <X11/Xatom.h>
#include <X11/Xlib.h>
#include <X11/Xmd.h>
#include <X11/Xutil.h>
#include <X11/Xproto.h>
#include <X11/keysym.h>
#include <X11/XKBlib.h>
#include <X11/Xft/Xft.h>
#include <ctype.h>


#include "rofi.h"
#include "textbox.h"
#include <glib.h>
#define SIDE_MARGIN    1

extern Display *display;

/**
 * Font + font color cache.
 * Avoid re-loading font on every change on every textbox.
 */
//
XftColor     color_fg;
XftColor     color_bg;
XftColor     color_fg_urgent;
XftColor     color_fg_active;
XftColor     color_bg_urgent;
XftColor     color_bg_active;
//
XftColor     color_hlfg;
XftColor     color_hlbg;
XftColor     color_hlfg_urgent;
XftColor     color_hlfg_active;
XftColor     color_hlbg_urgent;
XftColor     color_hlbg_active;
XftColor     color_bg_alt;
XVisualInfo  *visual_info;
Colormap     target_colormap;

PangoContext *p_context = NULL;

// Xft text box, optionally editable
textbox* textbox_create ( Window parent,
                          XVisualInfo *vinfo,
                          Colormap map,
                          TextboxFlags flags,
                          short x, short y, short w, short h,
                          TextBoxFontType tbft,
                          const char *text )
{
    textbox *tb = g_malloc0 ( sizeof ( textbox ) );

    tb->flags  = flags;
    tb->parent = parent;

    tb->x = x;
    tb->y = y;
    tb->w = MAX ( 1, w );
    tb->h = MAX ( 1, h );

    tb->layout = pango_layout_new ( p_context );

    unsigned int cp;
    switch ( tbft )
    {
    case HIGHLIGHT:
        cp = color_hlbg.pixel;
        break;
    case ALT:
        cp = color_bg_alt.pixel;
        break;
    default:
        cp = color_bg.pixel;
        break;
    }

    XSetWindowAttributes attr;
    attr.colormap         = map;
    attr.border_pixel     = cp;
    attr.background_pixel = cp;
    tb->window            = XCreateWindow ( display, tb->parent, tb->x, tb->y, tb->w, tb->h, 0, vinfo->depth,
                                            InputOutput, vinfo->visual, CWColormap | CWBorderPixel | CWBackPixel, &attr );

    PangoFontDescription *pfd = pango_font_description_from_string ( config.menu_font );
    pango_layout_set_font_description ( tb->layout, pfd );
    pango_font_description_free ( pfd );
    textbox_font ( tb, tbft );

    textbox_text ( tb, text ? text : "" );
    textbox_cursor_end ( tb );

    // auto height/width modes get handled here
    textbox_moveresize ( tb, tb->x, tb->y, tb->w, tb->h );



    // edit mode controls
    if ( tb->flags & TB_EDITABLE ) {
        tb->xim = XOpenIM ( display, NULL, NULL, NULL );
        tb->xic = XCreateIC ( tb->xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing, XNClientWindow, tb->window, XNFocusWindow, tb->window, NULL );
    }
    else {
        XSelectInput ( display, tb->window, ButtonPressMask );
    }

    return tb;
}

// set an Xft font by name
void textbox_font ( textbox *tb, TextBoxFontType tbft )
{
    switch ( ( tbft & STATE_MASK ) )
    {
    case HIGHLIGHT:
        tb->color_bg = color_hlbg;
        tb->color_fg = color_hlfg;
        break;
    case ALT:
        tb->color_bg = color_bg_alt;
        tb->color_fg = color_fg;
        break;
    case NORMAL:
    default:
        tb->color_bg = color_bg;
        tb->color_fg = color_fg;
        break;
    }
    if ( ( tbft & FMOD_MASK ) ) {
        if ( ( tbft & ACTIVE ) ) {
            if ( tbft & HIGHLIGHT ) {
                tb->color_fg = color_hlfg_active;
                tb->color_bg = color_hlbg_active;
            }
            else {
                tb->color_fg = color_fg_active;
                tb->color_bg = color_bg_active;
            }
        }
        else if ( ( tbft & URGENT ) ) {
            if ( tbft & HIGHLIGHT ) {
                tb->color_fg = color_hlfg_urgent;
                tb->color_bg = color_hlbg_urgent;
            }
            else {
                tb->color_fg = color_fg_urgent;
                tb->color_bg = color_bg_urgent;
            }
        }
    }
    tb->tbft = tbft;
}

// set the default text to display
void textbox_text ( textbox *tb, const char *text )
{
    g_free ( tb->text );
    const gchar *last_pointer = NULL;
    if ( g_utf8_validate ( text, -1, &last_pointer ) ) {
        tb->text = g_strdup ( text );
    }
    else {
        if ( last_pointer != NULL ) {
            // Copy string up to invalid character.
            tb->text = g_strndup ( text, ( last_pointer - text ) );
        }
        else {
            tb->text = g_strdup ( "Invalid UTF-8 string." );
        }
    }
    pango_layout_set_text ( tb->layout, tb->text, strlen ( tb->text ) );
    if ( tb->flags & TB_AUTOWIDTH ) {
        textbox_moveresize ( tb, tb->x, tb->y, tb->w, tb->h );
    }


    tb->cursor = MAX ( 0, MIN ( ( int ) strlen ( text ), tb->cursor ) );
}

void textbox_move ( textbox *tb, int x, int y )
{
    if ( x != tb->x || y != tb->y ) {
        tb->x = x;
        tb->y = y;
        XMoveResizeWindow ( display, tb->window, tb->x, tb->y, tb->w, tb->h );
    }
}
// within the parent handled auto width/height modes
void textbox_moveresize ( textbox *tb, int x, int y, int w, int h )
{
    if ( tb->flags & TB_AUTOHEIGHT ) {
        h = textbox_get_height ( tb );
    }

    if ( tb->flags & TB_AUTOWIDTH ) {
        pango_layout_set_width ( tb->layout, -1 );
        if ( w > 1 ) {
            w = MIN ( w, textbox_get_width ( tb ) );
        }
        else{
            w = textbox_get_width ( tb );
        }
    }
    else {
        // set ellipsize
        if ( ( tb->flags & TB_EDITABLE ) == TB_EDITABLE ) {
            pango_layout_set_ellipsize ( tb->layout, PANGO_ELLIPSIZE_MIDDLE );
        }
        else{
            pango_layout_set_ellipsize ( tb->layout, PANGO_ELLIPSIZE_END );
        }
    }

    if ( x != tb->x || y != tb->y || w != tb->w || h != tb->h ) {
        tb->x = x;
        tb->y = y;
        tb->w = MAX ( 1, w );
        tb->h = MAX ( 1, h );
        XMoveResizeWindow ( display, tb->window, tb->x, tb->y, tb->w, tb->h );
        pango_layout_set_width ( tb->layout, PANGO_SCALE * ( tb->w - 2 * SIDE_MARGIN ) );
    }
}

void textbox_show ( textbox *tb )
{
    XMapWindow ( display, tb->window );
}
void textbox_hide ( textbox *tb )
{
    XUnmapWindow ( display, tb->window );
}


// will also unmap the window if still displayed
void textbox_free ( textbox *tb )
{
    if ( tb == NULL ) {
        return;
    }
    if ( tb->flags & TB_EDITABLE ) {
        XDestroyIC ( tb->xic );
        XCloseIM ( tb->xim );
    }

    g_free ( tb->text );

    if ( tb->layout != NULL ) {
        g_object_unref ( tb->layout );
    }

    XDestroyWindow ( display, tb->window );
    g_free ( tb );
}

void textbox_draw ( textbox *tb )
{
    GC      context = XCreateGC ( display, tb->window, 0, 0 );
    Pixmap  canvas  = XCreatePixmap ( display, tb->window, tb->w, tb->h, visual_info->depth );
    XftDraw *draw   = XftDrawCreate ( display, canvas, visual_info->visual, target_colormap );

    // clear canvas
    XftDrawRect ( draw, &tb->color_bg, 0, 0, tb->w, tb->h );

    char *text       = tb->text ? tb->text : "";
    int  text_len    = strlen ( text );
    int  font_height = textbox_get_font_height ( tb );

    int  cursor_x     = 0;
    int  cursor_width = MAX ( 2, font_height / 10 );

    pango_layout_set_text ( tb->layout, text, text_len );

    if ( tb->flags & TB_EDITABLE ) {
        PangoRectangle pos;
        int            cursor_offset = 0;
        cursor_offset = MIN ( tb->cursor, text_len );
        pango_layout_get_cursor_pos ( tb->layout, cursor_offset, &pos, NULL );
        // Add a small 4px offset between cursor and last glyph.
        cursor_x = pos.x / PANGO_SCALE;
    }

//    pango_layout_set_width ( tb->layout, PANGO_SCALE * ( tb->w - 2 * SIDE_MARGIN ) );


    // Skip the side MARGIN on the X axis.
    int x = PANGO_SCALE * SIDE_MARGIN;
    int y = 0;

    if ( tb->flags & TB_RIGHT ) {
        int line_width = 0;
        // Get actual width.
        pango_layout_get_pixel_size ( tb->layout, &line_width, NULL );
        x = ( tb->w - line_width - SIDE_MARGIN ) * PANGO_SCALE;
    }
    else if ( tb->flags & TB_CENTER ) {
        int tw = textbox_get_font_width ( tb );
        x = ( PANGO_SCALE * ( tb->w - tw - 2 * SIDE_MARGIN ) ) / 2;
    }
    y = (  PANGO_SCALE * ( tb->h - textbox_get_font_height ( tb ) ) ) / 2;
    // Render the layout.
    pango_xft_render_layout ( draw, &( tb->color_fg ), tb->layout, x, y );

    // draw the cursor
    if ( tb->flags & TB_EDITABLE ) {
        XftDrawRect ( draw, &tb->color_fg,
                      x / PANGO_SCALE + cursor_x, y / PANGO_SCALE, // Align with font
                      cursor_width, font_height );
    }

    // flip canvas to window
    //  XClearWindow ( display, tb->window);
    XCopyArea ( display, canvas, tb->window, context, 0, 0, tb->w, tb->h, 0, 0 );

    XFreeGC ( display, context );
    XftDrawDestroy ( draw );
    XFreePixmap ( display, canvas );
}

// cursor handling for edit mode
void textbox_cursor ( textbox *tb, int pos )
{
    int length = ( tb->text == NULL ) ? 0 : strlen ( tb->text );
    tb->cursor = MAX ( 0, MIN ( length, pos ) );
}

// move right
void textbox_cursor_inc ( textbox *tb )
{
    int index = g_utf8_next_char ( &( tb->text[tb->cursor] ) ) - tb->text;
    textbox_cursor ( tb, index );
}

// move left
void textbox_cursor_dec ( textbox *tb )
{
    int index = g_utf8_prev_char ( &( tb->text[tb->cursor] ) ) - tb->text;
    textbox_cursor ( tb, index );
}

// Move word right
static void textbox_cursor_inc_word ( textbox *tb )
{
    if ( tb->text == NULL ) {
        return;
    }
    // Find word boundaries, with pango_Break?
    gchar *c = &( tb->text[tb->cursor] );
    while ( ( c = g_utf8_next_char ( c ) ) ) {
        gunichar          uc = g_utf8_get_char ( c );
        GUnicodeBreakType bt = g_unichar_break_type ( uc );
        if ( (
                 bt == G_UNICODE_BREAK_ALPHABETIC ||
                 bt == G_UNICODE_BREAK_HEBREW_LETTER ||
                 bt == G_UNICODE_BREAK_NUMERIC ||
                 bt == G_UNICODE_BREAK_QUOTATION
                 )
             ) {
            break;
        }
    }
    if ( c == NULL ) {
        return;
    }
    while ( ( c = g_utf8_next_char ( c ) ) ) {
        gunichar          uc = g_utf8_get_char ( c );
        GUnicodeBreakType bt = g_unichar_break_type ( uc );
        if ( !(
                 bt == G_UNICODE_BREAK_ALPHABETIC ||
                 bt == G_UNICODE_BREAK_HEBREW_LETTER ||
                 bt == G_UNICODE_BREAK_NUMERIC ||
                 bt == G_UNICODE_BREAK_QUOTATION
                 )
             ) {
            break;
        }
    }
    int index = c - tb->text;
    textbox_cursor ( tb, index );
}
// move word left
static void textbox_cursor_dec_word ( textbox *tb )
{
    // Find word boundaries, with pango_Break?
    gchar *n;
    gchar *c = &( tb->text[tb->cursor] );
    while ( ( c = g_utf8_prev_char ( c ) ) && c != tb->text ) {
        gunichar          uc = g_utf8_get_char ( c );
        GUnicodeBreakType bt = g_unichar_break_type ( uc );
        if ( (
                 bt == G_UNICODE_BREAK_ALPHABETIC ||
                 bt == G_UNICODE_BREAK_HEBREW_LETTER ||
                 bt == G_UNICODE_BREAK_NUMERIC ||
                 bt == G_UNICODE_BREAK_QUOTATION
                 )
             ) {
            break;
        }
    }
    if ( c != tb->text ) {
        while ( ( n = g_utf8_prev_char ( c ) ) ) {
            gunichar          uc = g_utf8_get_char ( n );
            GUnicodeBreakType bt = g_unichar_break_type ( uc );
            if ( !(
                     bt == G_UNICODE_BREAK_ALPHABETIC ||
                     bt == G_UNICODE_BREAK_HEBREW_LETTER ||
                     bt == G_UNICODE_BREAK_NUMERIC ||
                     bt == G_UNICODE_BREAK_QUOTATION
                     )
                 ) {
                break;
            }
            c = n;
            if ( n == tb->text ) {
                break;
            }
        }
    }
    int index = c - tb->text;
    textbox_cursor ( tb, index );
}

// end of line
void textbox_cursor_end ( textbox *tb )
{
    tb->cursor = ( int ) strlen ( tb->text );
}

// insert text
void textbox_insert ( textbox *tb, int pos, char *str )
{
    int len = ( int ) strlen ( tb->text ), slen = ( int ) strlen ( str );
    pos = MAX ( 0, MIN ( len, pos ) );
    // expand buffer
    tb->text = g_realloc ( tb->text, len + slen + 1 );
    // move everything after cursor upward
    char *at = tb->text + pos;
    memmove ( at + slen, at, len - pos + 1 );
    // insert new str
    memmove ( at, str, slen );
}

// remove text
void textbox_delete ( textbox *tb, int pos, int dlen )
{
    int len = strlen ( tb->text );
    pos = MAX ( 0, MIN ( len, pos ) );
    // move everything after pos+dlen down
    char *at = tb->text + pos;
    // Move remainder + closing \0
    memmove ( at, at + dlen, len - pos - dlen + 1 );
    if ( tb->cursor >= pos && tb->cursor < ( pos + dlen ) ) {
        tb->cursor = pos;
    }
    else if ( tb->cursor >= ( pos + dlen ) ) {
        tb->cursor -= dlen;
    }
}

// delete on character
void textbox_cursor_del ( textbox *tb )
{
    if ( tb->text == NULL ) {
        return;
    }
    int index = g_utf8_next_char ( &( tb->text[tb->cursor] ) ) - tb->text;
    textbox_delete ( tb, tb->cursor, index - tb->cursor );
}

// back up and delete one character
void textbox_cursor_bkspc ( textbox *tb )
{
    if ( tb->cursor > 0 ) {
        textbox_cursor_dec ( tb );
        textbox_cursor_del ( tb );
    }
}
static void textbox_cursor_bkspc_word ( textbox *tb )
{
    if ( tb->cursor > 0 ) {
        int cursor = tb->cursor;
        textbox_cursor_dec_word ( tb );
        if ( cursor > tb->cursor ) {
            textbox_delete ( tb, tb->cursor, cursor - tb->cursor );
        }
    }
}
static void textbox_cursor_del_word ( textbox *tb )
{
    if ( tb->cursor >= 0 ) {
        int cursor = tb->cursor;
        textbox_cursor_inc_word ( tb );
        if ( cursor < tb->cursor ) {
            textbox_delete ( tb, cursor, tb->cursor - cursor );
        }
    }
}

// handle a keypress in edit mode
// 0 = unhandled
// 1 = handled
// -1 = handled and return pressed (finished)
int textbox_keypress ( textbox *tb, XEvent *ev )
{
    KeySym key;
    Status stat;
    char   pad[32];
    int    len;


    if ( !( tb->flags & TB_EDITABLE ) ) {
        return 0;
    }

    len      = Xutf8LookupString ( tb->xic, &ev->xkey, pad, sizeof ( pad ), &key, &stat );
    pad[len] = 0;

    // Left or Ctrl-b
    if ( key == XK_Left ||
         ( ( ev->xkey.state & ControlMask ) && key == XK_b ) ) {
        textbox_cursor_dec ( tb );
        return 1;
    }
    // Right or Ctrl-F
    else if ( key == XK_Right ||
              ( ( ev->xkey.state & ControlMask ) && key == XK_f ) ) {
        textbox_cursor_inc ( tb );
        return 1;
    }

    // Ctrl-U: Kill from the beginning to the end of the line.
    else if ( ( ev->xkey.state & ControlMask ) && key == XK_u ) {
        textbox_text ( tb, "" );
        return 1;
    }
    // Ctrl-A
    else if ( ( ev->xkey.state & ControlMask ) && key == XK_a ) {
        textbox_cursor ( tb, 0 );
        return 1;
    }
    // Ctrl-E
    else if ( ( ev->xkey.state & ControlMask ) && key == XK_e ) {
        textbox_cursor_end ( tb );
        return 1;
    }
    // Ctrl-Alt-h
    else if ( ( ev->xkey.state & ControlMask ) &&
              ( ev->xkey.state & Mod1Mask ) && key == XK_h ) {
        textbox_cursor_bkspc_word ( tb );
        return 1;
    }
    // Ctrl-Alt-d
    else if ( ( ev->xkey.state & ControlMask ) &&
              ( ev->xkey.state & Mod1Mask ) && key == XK_d ) {
        textbox_cursor_del_word ( tb );
        return 1;
    }    // Delete or Ctrl-D
    else if ( key == XK_Delete ||
              ( ( ev->xkey.state & ControlMask ) && key == XK_d ) ) {
        textbox_cursor_del ( tb );
        return 1;
    }
    // Alt-B
    else if ( ( ev->xkey.state & Mod1Mask ) && key == XK_b ) {
        textbox_cursor_dec_word ( tb );
        return 1;
    }
    // Alt-F
    else if ( ( ev->xkey.state & Mod1Mask ) && key == XK_f ) {
        textbox_cursor_inc_word ( tb );
        return 1;
    }
    // BackSpace, Ctrl-h
    else if ( key == XK_BackSpace ||
              ( ( ev->xkey.state & ControlMask ) && key == XK_h ) ) {
        textbox_cursor_bkspc ( tb );
        return 1;
    }
    else if ( ( ev->xkey.state & ControlMask ) && ( key == XK_Return || key == XK_KP_Enter ) ) {
        return -2;
    }
    else if ( key == XK_Return || key == XK_KP_Enter ||
              ( ( ev->xkey.state & ControlMask ) && key == XK_j ) ||
              ( ( ev->xkey.state & ControlMask ) && key == XK_m ) ) {
        return -1;
    }
    else if ( !iscntrl ( *pad ) ) {
        textbox_insert ( tb, tb->cursor, pad );
        textbox_cursor_inc ( tb );
        return 1;
    }

    return 0;
}



/***
 * Font setup.
 */
static void parse_color ( Visual *visual, Colormap colormap,
                          const char *bg, XftColor *color )
{
    if ( strncmp ( bg, "argb:", 5 ) == 0 ) {
        XRenderColor col;
        unsigned int val = strtoul ( &bg[5], NULL, 16 );
        col.alpha = ( ( val & 0xFF000000 ) >> 24 ) * 255;
        col.red   = ( ( val & 0x00FF0000 ) >> 16 ) * 255;
        col.green = ( ( val & 0x0000FF00 ) >> 8  ) * 255;
        col.blue  = ( ( val & 0x000000FF )       ) * 255;
        XftColorAllocValue ( display, visual, colormap, &col, color );
    }
    else {
        XftColorAllocName ( display, visual, colormap, bg, color );
    }
}

void textbox_setup ( XVisualInfo *visual, Colormap colormap,
                     const char *bg, const char *bg_alt, const char *fg,
                     const char *hlbg, const char *hlfg
                     )
{
    visual_info     = visual;
    target_colormap = colormap;

    parse_color ( visual_info->visual, target_colormap, bg, &color_bg );
    parse_color ( visual_info->visual, target_colormap, fg, &color_fg );

    parse_color ( visual_info->visual, target_colormap, bg_alt, &color_bg_alt );
    parse_color ( visual_info->visual, target_colormap, hlfg, &color_hlfg );
    parse_color ( visual_info->visual, target_colormap, hlbg, &color_hlbg );

    parse_color ( visual_info->visual, target_colormap, config.menu_fg_active, &color_fg_active );
    parse_color ( visual_info->visual, target_colormap, config.menu_fg_urgent, &color_fg_urgent );
    parse_color ( visual_info->visual, target_colormap, config.menu_bg_active, &color_bg_active );
    parse_color ( visual_info->visual, target_colormap, config.menu_bg_urgent, &color_bg_urgent );
    parse_color ( visual_info->visual, target_colormap, config.menu_hlbg_active, &color_hlbg_active );
    parse_color ( visual_info->visual, target_colormap, config.menu_hlbg_urgent, &color_hlbg_urgent );
    parse_color ( visual_info->visual, target_colormap, config.menu_hlfg_active, &color_hlfg_active );
    parse_color ( visual_info->visual, target_colormap, config.menu_hlfg_urgent, &color_hlfg_urgent );

    PangoFontMap *font_map = pango_xft_get_font_map ( display, DefaultScreen ( display ) );
    p_context = pango_font_map_create_context ( font_map );
}


void textbox_cleanup ( void )
{
    if ( p_context ) {
        XftColorFree ( display, visual_info->visual, target_colormap, &color_fg );
        XftColorFree ( display, visual_info->visual, target_colormap, &color_fg_urgent );
        XftColorFree ( display, visual_info->visual, target_colormap, &color_fg_active );
        XftColorFree ( display, visual_info->visual, target_colormap, &color_bg );
        XftColorFree ( display, visual_info->visual, target_colormap, &color_bg_alt );
        XftColorFree ( display, visual_info->visual, target_colormap, &color_hlfg );
        XftColorFree ( display, visual_info->visual, target_colormap, &color_hlbg );
        g_object_unref ( p_context );
        p_context       = NULL;
        visual_info     = NULL;
        target_colormap = None;
    }
}

int textbox_get_width ( textbox *tb )
{
    return textbox_get_font_width ( tb ) + 2 * SIDE_MARGIN;
}

int textbox_get_height ( textbox *tb )
{
    return textbox_get_font_height ( tb ) + 2 * SIDE_MARGIN;
}

int textbox_get_font_height ( textbox *tb )
{
    int height;
    pango_layout_get_pixel_size ( tb->layout, NULL, &height );
    return height;
}

int textbox_get_font_width ( textbox *tb )
{
    int width;
    pango_layout_get_pixel_size ( tb->layout, &width, NULL );
    return width;
}

double textbox_get_estimated_char_width ( void )
{
    // Create a temp layout with right font.
    PangoLayout          *layout = pango_layout_new ( p_context );
    // Set font.
    PangoFontDescription *pfd = pango_font_description_from_string ( config.menu_font );
    pango_layout_set_font_description ( layout, pfd );
    pango_font_description_free ( pfd );

    // Get width
    PangoContext     *context = pango_layout_get_context ( layout );
    PangoFontMetrics *metric  = pango_context_get_metrics ( context, NULL, NULL );
    int              width    = pango_font_metrics_get_approximate_char_width ( metric );
    pango_font_metrics_unref ( metric );

    g_object_unref ( layout );
    return ( width ) / (double) PANGO_SCALE;
}

int textbox_get_estimated_char_height ( void )
{
    // Create a temp layout with right font.
    PangoLayout          *layout = pango_layout_new ( p_context );
    // Set font.
    PangoFontDescription *pfd = pango_font_description_from_string ( config.menu_font );
    pango_layout_set_font_description ( layout, pfd );
    pango_font_description_free ( pfd );

    // Get width
    PangoContext     *context = pango_layout_get_context ( layout );
    PangoFontMetrics *metric  = pango_context_get_metrics ( context, NULL, NULL );
    int              height   = pango_font_metrics_get_ascent ( metric ) + pango_font_metrics_get_descent ( metric );
    pango_font_metrics_unref ( metric );

    g_object_unref ( layout );
    return ( height ) / PANGO_SCALE + 2 * SIDE_MARGIN;
}