Unix GUI

Guntis BarzdinsGirts Folkmanis

Semestrvidus aptauja

Exceptions: MacOS X uses a proprietary Aqua windowing system (more efficient than X11), mobile phone interfaces

Classic X11

[Guntis-Computer:/usr/X11R6/bin] guntis% lsX luit xbiff xlsclientsXmark makedepend xcalc xlsfontsXnest makeg xclipboard xmagXprt makepsres xclock xmanXquartz makestrs xcmsdb xmessageXvfb mergelib xconsole xmhappres mkcfm xcursor-config xmkmfatobm mkdirhier xcutsel xmodmapbdftopcf mkfontdir xditview xonbdftruncate mkfontscale xdm xpropbeforelight mkhtmlindex xdpyinfo xrandrbitmap oclock xedit xrdbbmtoa proxymngr xev xrefreshccmakedep pswrap xeyes xsetcleanlinks quartz-wm xfd xsetmodecxpm resize xfindproxy xsetpointerdpsexec revpath xfontsel xsetrootdpsinfo rman xfs xsmdumpkeymap rstart xfsinfo xstdcmapeditres rstartd xft-config xtermfc-cache sessreg xfwp xtrapcharfc-list setxkbmap xgamma xtrapinfontconfig-config showfont xgc xtrapinfofreetype-config showrgb xhost xtrapoutfslsfonts smproxy xinit xtrapprotofstobdf startx xkbbell xtrapresetgccmakedep sxpm xkbcomp xtrapstatsglxgears texteroids xkbevd xvidtuneglxinfo twm xkbprint xvinfoiceauth ucs2any xkbvleds xwdico uxterm xkbwatch xwininfoimake viewres xkill xwudlbxproxy x11perf xloadlistres x11perfcomp xlogolndir xauth xlsatoms[Guntis-Computer:/usr/X11R6/bin] guntis% man xwud

Topics

X Windows X Protocol Classic X apps Starting X apps

Window managers Desktop environments Desktop applications

X Window

The X Window system was developed as part of Project Athena at MIT. In 1987, X Version 11 is released. X is now controlled and maintained by the Open Group.

The X Windows System, also referred to as ‘X’ or “X11”, is the standard graphical engine for Unix and Linux.

It is largely OS and hardware independent, it is network-transparent, and it supports many different desktops.

The Graphic User Interface in X

X Window uses a bit-mapped display where each pixel can be manipulated individually.

The entire display is known as the root window, and individual applications are displayed as windows on this root window.

X is started with the startx or xinit commands. X can also be invoked during system startup

X Protocol

The X Protocol provides a client-server architecture at the application level:

The X client is the processing part of the application and often runs on a remote machine.

The X server is the display and interaction system.

X Protocol cont’d

The X Protocol is also divided into device dependent and device independent layers.

X Server Design

Device Dependent Layer It is this layer that is responsible for localizing the X server to

the native environment, be it MS Windows or Solaris. This layer swaps bytes of data from machines with differing byte

ordering. Byte ordering (MSB and LSB) is noted in each X request.

This layer hides the architectural differences in hardware and operating systems.

Maintains device driver dependencies for keyboard, mouse and video.

Networked Windowing

X Window designed to allow apps to run on remote machines

Uses client-server model

X Serverstd system software

Clientapp software

Network

User

X architecture

The client-server nature of the X Protocol allows a single X server to support many clients (applications) on several hosts.

Client-Server Window System

Application 1 Application 2 Application nClient ApplicationPrograms

Virtualdisplay 1

Virtualdisplay n

Resourceallocator

Devicedriver

Window2 Window

n

Window1

MouseKeyboard

(After Fig 10.2, Dix, Finlay, Abowd and Beale)

Virtualdisplay 2

Server

Devices

Device-independent abstraction level

Translates abstraction into reality:one per terminal type

Could beWindowManager

X Protocol messages

Requests – client sends requests to the server (e.g. create window)

Replies – server response to client requests

Events – server forwards events (such as mouse clicks or keyboard entry) to the client

Errors – server reports errors to the client

X Server

The X server therefore: displays drawing requests on the screen. replies to information requests. reports an error in a request. Manages the keyboard, mouse and display device.

Multiplexes keyboard and mouse input onto the network (or via local IPC) to the respective X clients. (X events)

creates, maps and destroys windows. writes and draws in windows

X Client

sends requests to the server. receives events from server. receives errors from the server

Protocol Messages

Requests X clients make requests to the X server for a

certain action to take place. i.e.: Create Window To enhance performance, the X client normally

does not expect nor wait for a response. The request is typically left to the reliable network layer to deliver.

Protocol Messages

Replies The X server will respond to certain X client

requests that require a reply. As noted, not all requests require a reply.

Protocol Messages

Events The X server will forward to the X client an event

that the application is expecting. This could include keyboard or mouse input. To minimize network traffic, only expected events are sent to X clients.

X events are 32 bytes

Protocol Messages

Errors The X server will report errors in requests to the X

client. Errors are like an event but are handled differently.

X errors are the same size as events to simplify their handling. They are sent to the error handling routine of the X client.

X Windows Protocol OverviewX Windows is the predominate windowing system on UNIX computers, developed by the X Consortium, lead by M.I.T. An X server manages the display on the workstation. Clients can connect to server via TCP/IP and perform graphics operations. This makes X Windows much more network capable than Microsoft Windows, for example, which can only be accessed via a local API. X Windows operates over TCP, typically using server port numbers starting with 6000. The X server for a system's first display listens on port 6000; if the system has a second display, its server listens on port 6001; a third display would listen on 6002; etc. The protocol used over this reliable stream connection is essentially request/reply, and it's reputation is as a fat protocol that consumes a lot of bandwidth. Lightweight X (LWX), introduced in X11R6, attempts to reduces X's bandwidth needs to the point where it can be run over dialup modem connections.

The X Protocol, documented in a postscript file, defines dozens of messages that can be exchanged between a client and a server. They can generally be classified into four categories: Requests, Replies, Events, and Errors. Typical requests include Draw PolyLine, Draw Text, Create Window, Fill. Replies are matched to particular Requests. Events are asynchronous occurances such as keystrokes and mouse clicks. Errors are matched to particular Requests. If a window is partially or fully obscured by another, overlapping window, the server has two options available to it. The server can allocate additional memory, called backing store, to record to contents of the obscured window. This is purely optional, however. The server can simply ignore the obscured part of the window. Later, when that part of the window becomes visible again, the server sends an Expose event to the client, which must then redraw the affected area. The client, therefore, must be prepared to redraw any part of its windows at any time.

Applications do not need to access the X Windows protocol directly. X Windows supports several APIs. The most basic of these is Xlib, which interfaces fairly directly to the underlying network protocol. Most X client applications are linked against Xlib, which allows them to operate on either a local or remote X server, simply by adjusting either an environment variable or a command-line argument. Widgets layer on top of Xlib and provide X Windows with an object-oriented programming model. A widget is an X window capable of handling most of its own protocol interaction. The most popular widget sets are Athena Widgets (aw) and Motif. X Window's security model is all-or-nothing. Either an application can perform any operation on an X desktop, or it can perform none. There is no concept of limiting an application to a single top-level window, for example. Although there is power in this model, such as allowing the window manager to be a normal X client, there are also serious security implications. A hostile X client could connect to an X server and arrange to capture any screen image, or even to capture keystrokes as a password is being typing in one of the windows. For this reasons, X servers are typically fairly restrictive about which clients they will accept connections from. Two major security models are available. Host-based security (traditionally controlled by the xhost program), permits or denies connections based on their source IP addresses. Authentication (traditionally controlled by the xauth program), requires the connecting program to possess a secret password, typically stored in a UNIX file and subject to standard UNIX access controls. Kerberos-based authentication is also available.

Starting X Windows

On a local PC or workstation, you can usually start the X server with the “xinit” (“startx”) command or it may be started automatically by “xdm” (graphical login display).

Configuration stored in /etc/XF86ConfigUsually edited with utility /usr/X11R6/bin/xf86configor /usr/X11R6/bin/xf86cfg

xf86cfg

Configuring X Windows

mouseconfig Command used to configure a mouse for use by X

Windows xconfigurator

A program that is used to configure video adapter card and monitor information for use by X Windows

redhat-config-xfree86 used in recent Red Hat & in Fedora

Configuring X Windows

Fedora and X Windows configuration Fedora has greatly improved video & monitor

detection Not included in Fedora (Red Hat only):

SuperProbeXf86configXconfigurator

Starting X applications

To launch an X client from a remote host for display on the local X server, you need to set two things:1) Permission for the remote host to display X clients on the local machine.

xhost +remotehost2) The target display for the remote application.

setenv DISPLAY=server:display

[hostname]:displaynumber[.screennumber]

not needed, if same host

“0” in most cases defaults to “0”

/etc/X11/xinit/xinitrc (xinit)or /home/g/.xsession (xdm)

#!/bin/sh# $Id: xinitrc,v 1.2 2003/02/27 19:03:30 jharper Exp $

xrdb -load $HOME/.Xresources

xsetroot -solid gray &xclock -g 50x50-0+0 -bw 0 &

xterm &

# start the window manager

exec twm

#!/bin/sh# $Id: xinitrc,v 1.2 2003/02/27 19:03:30 jharper Exp $

xrdb -load $HOME/.Xresources

xsetroot -solid gray &xclock -g 50x50-0+0 -bw 0 &

xterm &

# start the window manager

exec twm

last line: replaces shell-script with window manager, will terminate all background processes on exit

loads resources: default fonts, colours, window sizes

xinit executes this script

GUI History In 1962, Douglas Engelbart invented the

first “mouse,” which he called an “X-Y Position Indicator.”

It was a little gizmo housed in a wooden box on wheels that moved around the desktop and took the cursor with it on the display.

Source: US Patent Office

GUI History

In 1963 a grad student at MIT, Ivan Sutherland, submitted as his thesis a program called “Sketchpad.” This was the first GUI (Graphical User Interface) long before the term was coined."

http://accad.osu.edu/~waynec/history/images/ivan-sutherland.jpg

GUI History

In the 1970s, at Xerox’s PARC facility, Alan Keys created an object-oriented graphical programming language called “Smalltalk.” Smalltalk featured a graphical user interface (GUI) that looked suspiciously similar to later iterations from both Apple and Microsoft.

http://www.sra.co.jp/people/aoki/SqueakIdioms/chapter01/Xerox1100SIP.jpg

GUI History

1981, Xerox attempted to market the “Star.” It introduced the idea of what you see is what you get (WYSIWYG).

Commercial failure cost ($15,000);

IBM had just announced a less expensive machine

limited functionality e.g., no spreadsheet

closed architecture, 3rd party vendors could not add

applications perceived as slow

but really fast! slavish adherence to direct manipulation

http://www.catb.org/~esr/writings/taouu/html/graphics/xerox_star.jpg

Apple gets a GUI In 1983, the Apple Lisa was

first GUI offering.

http://fp3.antelecom.net/gcifu/applemuseum/lisa2.html

http://www.s-line.de/homepages/horber-privat/bilder/apple2a.jpg

Apple II, 1980

Lisa

Apple gets a GUI In 1984, Macintosh was the first computer with

a GUI marketed to the masses. “old ideas” but well done!

Commercial success because: aggressive pricing ($2500) did not need to trail blaze

learned from mistakes of Lisa and corrected them; ideas now “mature”

market now ready for them developer’s toolkit encouraged 3rd party non-

Apple software interface guidelines encouraged consistency

between applications domination in desktop publishing because of

affordable laser printer and excellent graphics

Full Microsoft Office suite(Apple was the dominant player at this time.)

http://computermuseum.50megs.com/images/collection/apple-mac-plus.jpg

http://toastytech.com/guis/bigmac1.gif

Microsoft Gets a GUI Microsoft introduced Windows

1.0 in 1985 Tiled Windows, no overlapping

Windows 2.03 in 1987 Overlapping windows

Windows 3.0 in 1990 Features Program Manager

Unix Gets a GUI The X Windows System was introduced

in the mid-1980s to provide graphical support for unix operating systems.

The implementation was a client-server approach, where an X window system server ran on the displaying machine, and the client programs communicated with it using a network protocol.

X provides only a communication mechanism, not policy. At least three major user interface look & feel styles are widely used on X - MIT's own Athena style, Sun and AT&T's OpenLook, and OSF's Motif (supported primarily by HP and IBM).

http://www.pattosoft.com.au/jason/Articles/HistoryOfComputers/X11.gif

Shells Unix and DOS operating systems circa 1980s support text-based user

interfaces via a program called a shell. These shells insert another layer between the user and the operating system. Typical text shells under unix are csh and ksh. The typical text shell under microsoft is command.com. It is still emulated today by cmd.exe.

Original unix and Microsoft GUI support was also implemented as shells. The dominant unix GUI library became an open library called X11 supported by the X.org foundation. Microsoft introduced Windows 1.0 as a shell that ran on a layer above MS-DOS.

The original Apple GUI is embedded into its operating system kernel. Windows migrated to embedding GUI support beginning with Windows NT.

Windows Timeline

It took roughly 15 years to consolidate its shell-based GUI architecture offerings with its embedded GUI architecture offerings.

http://www.microsoft.com/windows/WinHistoryProGraphic.mspx

Window managersOne can use X11 without a window manager.

Typically, one writes a session script which starts an "xterm" at a "-geometry" location. One then starts other X11 clients by giving their "-geometry" explicitly, because there is no window manager

The window manager is a special X client that controls the placement and movement of applications, provides title bars and control buttons, menus and taskbars. Some support virtual desktops and very fancy graphics.

When a window manager is running, some of interaction between the X server and its clients is redirected through the window manager.

Classic window managers include: TWM MWM - Motif Window Manager

Nowadays, KDE (kwm) and GNOME (sawfish) are two widely used window managers in Linux.

The Tab Window Manager (TWM)

xterm

The most important X application is, rather ironically, the terminal program xterm.

Old school xterm:

xterm: The Main Client

You can invoke all UNIX commands and X programs form the UNIX command line available in an xterm window.

xterm can also be used with a scrollbar (-sb), and the number of lines saved can be specified (-sl). You can position and specify the size and position of a window (-

geometry) and its foreground and background color (-fg and -bg).

You can start a program as an icon (-icon) and provide a name (-name) or title (-title).

Some classic X apps

xclock – pretty self-explanatory

Some classic X apps

xeyes – ok, this is really the most important

xnest

XFree86

“In short, XFree86 is an open source X11-based desktop infrastructure.” – xfree86.org

X.org Foundation – sucessor of XFree86

Used in most Linux distributions

Window managers,Widget toolkits,

Desktop environments,Desktop applications

X and the GUI

X itself provides the back end needed for a GUI. It doesn’t, however, provide an interface itself.

Window management functions – e.g. moving or resizing windows – are performed by a window manager, which is itself an X client. These range from the spartan (twm) to the complex and graphically intensive (Enlightenment).

There are various different toolkits for creating graphical applications, providing libraries of widgets such as buttons etc. These range from the old and ugly (Motif) to the new and shiny (GTK+, Qt)

No two users can be assumed to have the same window manager and different applications can use different toolkits (or even write their own). Therefore, there’s a lack of consistency about the average X desktop – this makes things ugly and can be hard to use.

Why not only a basic X11 environment?

Most X11 applications have important shortcomings: Application Interoperability is too hard User Interface is inconsistent and of unequal quality

Modern desktop environment brings the "glue" Drag & Drop, Session Management, etc... Consistent "look and feel" Unified Help System Easy dialog based desktop configuration Common application development framework (-> MFC) Compound document framework (-> OLE)

New exciting possibilities: Hundreds of new applications (including Office) Powerful application development environment

Linux GUI Components

Desktop Environment

Window Manager

X Windows

Graphical Programs (X clients)

Video Adapter Card Hardware

Motif Window manager and Widgets

KDE

KDE is the traditional desktop environment used on Linux systems

K Windows Manager (kwm) The window manager that works under the KDE

Desktop Environment Qt toolkit

Software toolkit used with the KDE Desktop environment

Linux Developement

Qt Class Library C++ Cross Platform

Qt/Windows Qt/X11 (Linux, Solaris, HPUX,

AIX, etc) Qt/Mac

GPL – Free for non-commercial apps Qt was used to build KDE from Trolltech in Norway www.trolltech.com

Gnome

GNOME Desktop Environment Default desktop environment in Red Hat Linux Typically uses the Sawfish Window Manager and

the GTK+ toolkit for the C programming languageThe GTK+ toolkit was originally developed for the

GNU Image Manipulation Program (GIMP)Ported also to MS Win, MacOS X planned

Bluecurve

Bluecurve Both a visual theme and a set of modifications to

the KDE and GNOME environments Gives both a common “look & feel” Smooths out inconsistent behaviors between the

different WMs

The KDE Desktop Environment

The Bluecurve + KDE in Fedora

The GNOME Desktop Environment

The Bluecurve + GNOME in Fedora

KDE and Gnome architectures

What is a desktop?

It is the top of a desk

It is a pc cabinet for the desktop

It is the graphical user interface (GUI) on a pc

It is the graphical enviroment for the average user on a pc

KDE and GNOME

K Desktop Environment KDE is a "complete desktop environment that try to

make linux accessible to everybody" At present KDE 3.5

GNU Network Object Model Environment AIM: "GNOME Intends to build a complete, user-

friendly desktop, similar to CDE or KDE, but based entirely on free software"

At present GNOME 2.14

KDE

http://www.kde.org/

KDE

GNOME

http://www.gnome.org/

Render Extension Render Extension - - ShadowsShadows

Render Extension Render Extension - - TranslucencyTranslucency

Render Extension Render Extension – – anti-alias fontanti-alias font

SuperKaramba -SuperKaramba -dynamic background infodynamic background info

More GUI on Linux

X Window server Window Managers

KDE GNOME WindowMaker FVWM Enlightenment IceWM CorelLinux

WindowMaker

http://www.windowmaker.org/

FVWM

http://www.fvwm.org/

Enlightment

http://www.enlightenment.org/

IceWM

http://iceorg.sourceforge.net/

Corel Linux

http://linux.corel.com/

Office suites for Linux WordPerfect Office

ApplixWare

StarOffice

GNOME Office

KOffice

StarOffice / OpenOffice / LibreOffice

SUN Microsystems Writer Calc Impress Draw Base

Danish in june Free, not Open Source

KOffice

KDE project KWord KSpread

Kpresenter Killustrator KChart

Open Source

GNOME Office

GNOME project AbiWord Gnumeric GIMP Dia GNOME-DB

Open Source

Other desktop applications

GIMP Image editor á la Adobe

Photoshop Free and open Thousands of plug-ins

Mozilla Webbrowser (Firefox) Mailclient (Thunderbird)

Office Suites

StarOffice KDE GNOME MS WindowsSpreadSheet StarCalc Kspread Gnumeric ExcelPresentation StarImpress Kpresenter Achtung PowerPointVector Drawing StarDraw Killustrator Gill PaintWord Processor StarWriter Kword AbiWord WordChart Drawing StarChart Kdiagramm Guppi Excel Graphic FeatureFormula Editor StarMath Kformula Equation Editor Image Processor StarImage Kimage Gimp Ms. ImageDiagram Creation Dia VisioPlanning Events StarScheduleCalendar Korganizer Gcalendar

Using X windows remotely on a MS-Windows machine.

You need to get a program called an “Xserver”. Exceed works well and is free for academic use. Cygwin is another option.

You must allow X-forwarding through your ssh client. Putty is good for this.

X server security configuration

xhost xhost simply allows you to specify which machines are, or aren't allowed to connect to the X server, this is a very simplistic security mechanism and is not really suitable in any modern environment, however used in conjunction with other mechanisms it can help. The command is quite simple: 'xhost +example.org' adds example.org, 'xhost -example.org' removes example.org from the list, you must also specify 'xhost -' to turn on the access control list, or else everyone is let in by default.

mkxauth mkxauth is definitely a step up from xhost. mkxauth helps create ~/.Xauthority files, and merge them, which are used to specify hostnames and the related magic cookies (basically a token used to gain access). These cookies can then be used to gain access to a remote X host (you essentially have a copy of the cookie on each end) and are transferred either plain text (insecure) or DES encrypted (quite secure). Using this method you can be relatively safe and secure. Xauthority files can also be used in conjunction with Kerberos, removing the necessity to copy Xauthority files around and keep them in synchronization. Hosts authenticate to each other through a central Kerberos key server(s) in an encrypted fashion, this method is most appropriate for large installations/etc. mkxauth has an excellent man page 'man mkxauth' and more generalized details are available in the Xsecurity man page (not sure how common this name page is) 'man Xsecurity'.

SSH tunnelSSH or OpenSSH can be used to create a tunnel between hosts (or more specifically between two X servers), thus encrypting the channel, providing authentication, and generally making things safer. The following web page explains it http://csociety.ecn.purdue.edu/~sigos/projects/ssh/forwarding/.

Mac OS X

Mac OS X ArchitectureApple’s Boiled Sweets diagram

http://developer.apple.com/macosx/architecture/

The Smartphone Platform

With the iPhone being the first to the marketplace it sets the configuration of the Smartphone Platform

3G/4G connectivity WiFi connectivity Bluetooth connectivity accelerometer w/compass ambient light sensor proximity sensor GPS gyroscope

What is iOS

Apple’s mobile OS for phones (iPhone), tablets (iPad), handhelds (iPod),

based on BSD Unix Application programming done in Objective C Supports Bluetooth, Wi-Fi, and 3G and 4G

networking

Apple iOS

What is Android Android is an open source operating system,

created by Google specifically for use on mobile devices (cell phones and tablets)

Linux based (2.6 kernel) Can be programmed in C/C++ but most app

development is done in Java (Java access to C Libraries via JNI (Java Native Interface))

Supports Bluetooth, Wi-Fi, and 3G and 4G networking

The Android Software Stack

Main GUI parts

Status Bar

Home Screen

App Screen

Favourites Tray

Navigation bar(Android 3.0+)

Commonly Used Packages

User interface controls and widgets User interface layout Secure networking and web browsing Structured storage and relational databases (SQLite

RDBMS) 2D and 3D Graphics SGL and OpenGL Audio and visual media support Access to optional hardware (GPS)

Security

Semantic

Android Application Development

Eclipse IDE

AndroidSDK

AndroidEmulato

r

AndroidMobileDevice

iOS Application Development

XCODE IDE

iOSSDK

iOSSimulat

or

iOSMobileDevice

Android development

Android Manifest

Resource XML

Java Source

Generated Class

Java Compile

rAndroid Libraries

.dexFile

DalvikVM

iOS development

Objective C Source .xib file Objective

C Compiler

Foundation FrameworkCocoa Libraries

. Simulator or

Device

Interface Builder

Xcode

Sams Teach Yourself Android™Application Development in 24 Hours (0321673352)

Copyright ©2010 Lauren Darcey and Shane Conder

FIGURE 5.6 Simplified Android platform architecture from a security perspective.

UI With GUI Builder

Android Basics• Open source OS

• Uses Linux kernel• Optimized for limited-resource environment

• Apps typically written in Java• Apps run on the Dalvik Virtual Machine

• Not a JVM, but works similarly from developer’s point of view

• Usually one app per DVM• Each DVM runs under Linux as a separate user• App permissions set at install time

• Possible to use C or C++ compiled to machine code, but still runs on VM.