sudo apt-get install wmctrl

(defun darkroom-mode ()
        (interactive)

        (shell-command "wmctrl -r darkroom -badd,fullscreen")

        (set-background-color "black")
        (set-foreground-color "green")

        (set-cursor-color "white")
        (setq left-margin 10)
        (menu-bar-mode -1)
        (tool-bar-mode -1)
        (scroll-bar-mode -1)
        (transient-mark-mode 1)


        (set-face-foreground 'region "black")
        (set-face-background 'region "green")

        (set-face-foreground 'mode-line "gray15")
        (set-face-background 'mode-line "black")

        (move-to-left-margin 0 1)
        (auto-fill-mode)
        (setq text-mode-hook 'darkroom-mode)

)

emacs -f darkroom-mode  -title darkroom -fn -adobe-courier-medium-r-normal--25-180-100-100-m-150-iso8859-1 foo.txt

mkdir aedit
cd aedit

gedit main.cpp

/*
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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

/*
    This program is simply a sensory-deprivation themed text editor, for concentration purposes.
    CTRL+SHIFT+BACKSPACE quits, CTRL+SHIFT+S saves. The first line is used as the filename.
    Compile with -DSCROLL option to enable a vertical scrollbar.
*/

#include <gtk/gtk.h>
#include <gdk/gdkkeysyms.h>
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

void Destroy();
gboolean Accel(GtkAccelGroup *accel_group, GObject *acceleratable, guint keyval, GdkModifierType modifier);
void modify_cursor_color(GtkWidget *widget, GdkColor *color);

GtkWindow *window = NULL;
GtkWidget *scroll = NULL;
GtkWidget *edit = NULL;

/* the main program is given as a DLL when compiled for Windows to allow the main program to locate the GTK
   runtimes before executing the program itself. This is irrelevant to any other platform. */
#ifdef _WIN32
#include <windows.h>
extern "C" __declspec(dllexport) int Main(int argc, char *argv[]){
#else
int main(int argc, char *argv[]){
#endif

    gtk_init(&argc,&argv);

    // create the window
    window = (GtkWindow*)gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_fullscreen(window);
    gtk_window_set_title(window,"Editor");
    gtk_window_set_keep_above(window,true);
    gtk_widget_set_size_request(GTK_WIDGET(window),600,400);
    g_signal_connect(window,"delete_event",G_CALLBACK(Destroy),NULL);
    edit = gtk_text_view_new();
    //set the side margins for maximum readability
    gtk_text_view_set_left_margin(GTK_TEXT_VIEW(edit),256);
    gtk_text_view_set_right_margin(GTK_TEXT_VIEW(edit),256);
    gtk_widget_set_name(edit,"GtkEditorView");
    gtk_text_view_set_wrap_mode(GTK_TEXT_VIEW(edit),GTK_WRAP_WORD);
    scroll = gtk_scrolled_window_new(NULL,NULL);

    // simply add a scroll window to allow for convenient scrolling capabilities like the mouse wheel
    gtk_container_add(GTK_CONTAINER(window),scroll);
    ((GtkScrolledWindow*)scroll)->hscrollbar_policy = GTK_POLICY_NEVER;
#ifdef SCROLL
    ((GtkScrolledWindow*)scroll)->vscrollbar_policy = GTK_POLICY_AUTOMATIC;
#else
    ((GtkScrolledWindow*)scroll)->vscrollbar_policy = GTK_POLICY_NEVER;
#endif
    gtk_container_add(GTK_CONTAINER(scroll),edit);

    GdkColor color;
    gdk_color_parse("black",&color);
    gtk_widget_modify_base(edit,GTK_STATE_NORMAL,&color);

    gdk_color_parse("green",&color);
    gtk_widget_modify_text(edit,GTK_STATE_NORMAL,&color);

    gdk_color_parse("yellow",&color);
    modify_cursor_color(edit,&color);

    // set the font to monospace
    GtkTextBuffer *buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(edit));
    PangoFontDescription *font_desc = pango_font_description_from_string("Courier New,Monospace 12");
    gtk_widget_modify_font(edit,font_desc);
    pango_font_description_free(font_desc);

    // if specified in the command prompt, attempt to open a file
    if (argc > 1){
        ifstream file(argv[1]);
        if (file){

            // prepend the file name on its own line for saving purposes
            string body = argv[1];
            body.append("\n");
            while (file && file.peek() != EOF) body += file.get();
            gtk_text_buffer_set_text(buffer,body.c_str(),body.length());
        }
    } else {
        // if no file is specified, simply provide a quick introduction
        string intro =  "filename.txt\n\n"
                "CTRL+SHIFT+BACKSPACE to quit (without saving)\n"
                "CTRL+SHIFT+S to save (first line is used as filename)\n";
        //Comment the next line if you don't want the initial text shown.
        gtk_text_buffer_set_text(buffer,intro.c_str(),intro.length());
    }

    GtkAccelGroup *accel = gtk_accel_group_new();
    GClosure *closure;
    GdkModifierType CTRL_SHIFT = (GdkModifierType)(GDK_CONTROL_MASK | GDK_SHIFT_MASK);

    // add the quit shortcut
    closure = g_cclosure_new(G_CALLBACK(Accel),NULL,NULL);
    gtk_accel_group_connect(accel,GDK_BackSpace,CTRL_SHIFT,(GtkAccelFlags)0,closure);

    // add the save shortcut
    closure = g_cclosure_new(G_CALLBACK(Accel),NULL,NULL);
    gtk_accel_group_connect(accel,GDK_S,CTRL_SHIFT,(GtkAccelFlags)0,closure);

    gtk_window_add_accel_group(window,accel);
    gtk_widget_show_all(GTK_WIDGET(window));

    // enter the main application loop
    gtk_main();

    return 0;
}

void Destroy(){
    gtk_main_quit();
}

gboolean Accel(GtkAccelGroup *accel_group, GObject *acceleratable, guint keyval, GdkModifierType modifier){
    if (keyval == GDK_BackSpace)
        Destroy();
    else if (keyval == GDK_S || keyval == GDK_s){
        GtkTextIter start, end;
        GtkTextBuffer *buffer = gtk_text_view_get_buffer(GTK_TEXT_VIEW(edit));
        gtk_text_buffer_get_start_iter(buffer,&start);
        gtk_text_buffer_get_iter_at_line(buffer,&end,1);
        gchar *line = gtk_text_buffer_get_slice(buffer,&start,&end,false);
        if (!line) return true;

        if (line[0]){
            for (int i = 0; line[i] != 0; i++){
                if (line[i] == '\b' || line[i] == '\r' || line[i] == '\n') line[i] = 0;
            }
            ofstream file(line);
            start = end;
            gtk_text_buffer_get_end_iter(buffer,&end);
            gchar *body = gtk_text_buffer_get_slice(buffer,&start,&end,false);
            file << body;
            g_free(body);
            file.close();
        }

        g_free(line);
    }
    return true;
}

/*
Thanks to gedit source:
A hack to change the cursor color (widget must be named!)
*/
void modify_cursor_color(GtkWidget *widget, GdkColor *color){
    static const char cursor_color_rc[] =
        "style \"editor\"\n"
        "{\n"
            "GtkTextView::cursor-color=\"#%04x%04x%04x\"\n"
        "}\n"
        "widget \"*.%s\" style : application \"editor\"\n";

    const gchar *name;
    gchar *rc_temp;

    name = gtk_widget_get_name(widget);
    if (!name) return;

    if (color){

        rc_temp = g_strdup_printf(cursor_color_rc,
                color->red,
                color->green,
                color->blue,
                name);

    } else {
        GtkRcStyle *rc_style;

        rc_style = gtk_widget_get_modifier_style(widget);

        rc_temp = g_strdup_printf(cursor_color_rc,
                rc_style->text[GTK_STATE_NORMAL].red,
                rc_style->text[GTK_STATE_NORMAL].green,
                rc_style->text[GTK_STATE_NORMAL].blue,
                name);
    }

    gtk_rc_parse_string(rc_temp);
    gtk_widget_reset_rc_styles(widget);

    g_free(rc_temp);
}

g++ -o editor main.cpp `pkg-config --cflags gtk+-2.0` `pkg-config --libs gtk+-2.0`

./editor