1. NexTk/NtkWidget
A replacement for Tk ?! 1

2. History of NexTk
George Peter Staplin (GPS) started ~ 2 years ago with a system for handling widgets
Original title Tk9
Name changed to NexTk
NtkWidget is based on NexTk 2

3. Architecture of TK
Based on X11, support for windows and MacOS a lot of years later
Basic widgets are implemented completely in C
Widget parts are built and displayed using X11 (client- )functions
Use of system fonts
Options for widgets are additionally using an option database
Geometry managers: grid, pack and place
No alpha blending, no free rotation of texts 3

4. Structure of Tk Entry Widget (Tcl-code)‏ Button Widget (Tcl-code)‏
Text
Widget
(Tcl-code)‏
Entry
Widget
(C-code)‏
Button
Widget
(C-code)‏
Text
Widget
(C-code)‏
Tk Base
Layer
(C-code)‏
X11
Server
(unix/linux)‏
API and
GDI
(windows)‏
X11/native
Server
(MacOS)‏ 4

5. Architecture of NexTk (1)‏
Widgets und widget parts are built as images
Widget code is Tcl code
Images are built using megimage functions
Freetpyeext for fonts/text
Geometry managers: grid, pack(planned), place(planned)‏
With alpha blending, with free text rotation 5

6. Components of NexTk megaimage: pixel image and blending functions
freetypeext: extension of freetype fonts for building text images and rotating texts
objstructure: extension for building simple objects
ntk: the collection of Tcl code building the base widgets 6

7. Architecture of NexTk (2)‏
Every pixel consists of 4 bytes r/g/b and alpha
Ntk package is handling root windows and mouse and key events
Use of openGL for displaying
Running on linux and win32 at the moment 7

8. Architecture of ntkWidget (1)‏
Based mostly on NexTk with the following differences
Use of itcl instead of objstructure and use of ntkWidgetImage instead of megaimage
Use of GLMWFW (Graphic Library Multi Window FrameWork) as common platform independent base for handling root windows and mouse/key events
Widget parts are constructed using itcl-ng classes with inheritance instead of objstructure 8

9. Architecture of ntkWidget (2)‏
In the future: use of ttk(tile) like architecture for handling themes (also using itcl-ng classes)‏
ttk like theme handling implemented about 70%‏
Namespace ensemble subcommands for the functionality, so no need to learn itcl for users of the package
Linux only at the moment (no development environment for windows MacOS)‏ 9

10. Structure of ntkWidget…
label
button
entry …
grid
render
freetype
megaimage
GLMWFW (Graphic Library Multi Window FrameWork)‏
openGL
X11-Server
(unix/linux)‏
GDI-Library
(win32)‏
X11-Server
(MacOS)‏ 10

11. Building Tk like widgets
Widget parts are for example: window, border, text, scrollbar
Every widget part is an image (a rectangle, a polygon, a text)‏
Widget parts are put together using blending functions (megaimage)‏
Transparency (alpha factor) is taken care of during blending
The root window is also a widget/image which is handled during blending 11

13. ntkWidget Hierarchy helpers render gridManager gridData window grid
theme / ttk theme
pack
button
place 13

14. ntkWidget base widgets
Box
Button
Checkbox
Clock
Entry
Frame
Listbox
Menu
Text
Toplevel 14

15. ntkWidget commands ::ntk toplevel [options] ntk button [options]
ntk checkbox [options]
ntk clock [options] :
ntk window [options]
ntk keyPress [options]
ntk mousePress [options]
ntk widgetImage [options]

16. ntkWidget code example
package require ntkWidget
# set the root windows title
::ntk::glmwfw::Glmwfw setWindowTitle $ntk::_win "NtkWidget Button Demo"
proc flipName {win} {
set name [$win cget -text]
switch $name {
Arnulf {
$win configure -text Wiedemann }
Wiedemann {
$win configure -text Arnulf
set rotate 0
if {[llength $argv] > 0} {
set rotate [lindex $argv 0]
set wPath [ntk button .w -width 100 -height 100 -xoffset 50 -yoffset 50 \
-text Arnulf -textcolor [list ] -bd 2 -bg [list ]]
$wPath configure -command [list flipName $wPath] -rotate $rotate
# pack the widget using ntkWidget grid manager
ntk grid $wPath

17. Ttk style -anchor center -padding [list 3 3] -width -9 -relief raised
Default style Tbutton options
Clam style Tbutton options
-anchor center
-padding [list 3 3]
-width -9
-relief raised
-shiftrelief 1
-window #ffffff
-frame #d9d9d9
-disabledfg #a3a3a3
-anchor center
-padding 5
-width -11
-relief raised
-window #ffffff
-frame #cdad5
-disabledfg #999999 17

18. Ttk layout Default layout TButton Clam layout TButton Background
Border
Focusring
Padding
Text
Background
Border
Focusring
Padding
Text 18

19. Ttk state active alternate background disabled focus invalid pressed
readonly
selected 19

20. Ttk style map -background [list disabled #9d9d9d active #ececec]
-foreground [list disabled #a3a3a3
-relief [list {pressed !disabled} sunken] 20

21. Ttk theme names
alt
aqua
clam
classic
default 21

22. Ttk like features With ttk like features you can
Determine the layout of a widget using a theme
Determine the style of a widget using a theme
Determine the look of a widget depending on the state
No need to change the widget code
Different look and feel on platforms dependent on default layout for the platform 22

23. ntkWidget andTtk like features
The currently used theme class in ntkWidget will be replaced by the ttk like features
The mechanisms used in Ttk are very similar to the mechanisms used in ntkWidget (widget parts -> layout)‏
The currently used methods in the ntkWidget theme class can be modified to handle styles
The rendering can be easily adapted to handle layouts
The rendering will be enhanced to handle states 23

24. itcl-ng addons for ntkWidget
methodvariable
option
delegate method
delegate proc
delegate option 24

25. itk and ntkWidget why not use itk? depending on Archetype
inheritance of options
strange option handling of inherited options
depending on Tk
no support of themes possible 25

26. Status NexTk and ntkWidget are work in progress
NexTk and ntkWidget developers are working together
There exist demos for NexTk
There exist small demos for ntkWidget (without ttk like themes)‏ 26

27. Conclusions
NexTk and ntkWidget could be both a replacement for Tk in the future
A huge amount of work to be done before usable as replacement for Tk
Newer technology, easier to maintain code base
Additional developpers would speed up implementation
Will be incompatible to Tk on some places 27

28. ntkWidget „hello world“
Now it is time for some small demo examples 28