It's all about a bar of tabs. Or a tab bar if you like it more.

The tab bars are widely used in various editors, e.g. in alited, TKE, Geany, Kate, Pluma - all very good for Tcl/Tk programming, by the way.

If you need a Tcl/Tk widget similar to the tab bars of those editors, you might try bartabs.

The bartabs is a tab bar widget with a lot of options. It can be used as an independent widget or along with apave package as bts widget.

Specifically, bartabs does its best in alited.

The bartabs package provides Tcl/Tk widget containing tabs, with the following features:

• scrollable tabs
• moveable tabs
• closeable tabs
• drag-and-drop tabs
• disabled and enabled tabs
• static and changeable bars
• selectable and multi-selectable tabs
• tooltips on tabs and popup menu's items
• tabs can be marked with a color or an image
• tabs can fire user commands at closing, selecting, moving
• tabs can be sorted, including user commands to compare tabs
• bars and tabs are configureable, including user options (little database)
• bars are enhanced with popup menus, including user items and submenus
• bars and tabs may be changed "on fly" (move, scroll, delete, insert, rename etc.)
• at need, there may be multiple independent Bar objects controlled by one Bars object

A common appearance of bartabs is below:

Here the details are:

• the current file is test2_pave.tcl
  • its full name is displayed by a caller of bartabs
• currently hovered file is test_pavedialog.tcl
  • its name is displayed short, due to the -lablen 16 option
  • so, its real name is displayed by bartabs in the tip
  • its tab has Close button at the right
• Scroll left and Scroll right buttons are at both edges of bartabs
• Scroll right button is disabled, as there are no tabs beyond the right edge

A bit customized versions of bartabs may look like the following.

Here the details are:

• a color scheme is changed
• the hovered tab has no tip, as its label isn't shortened
• Scroll right button is enabled, as two tabs were scrolled to the right

Here the details are:

• tabs have no border due to -bd 0 option
• bartabs got -static yes option, so the hovered tab has not Close button

Here the details are:

• bartabs is made -static no -bd 1 again
• currently edited file is underlined instead of blue background, due to -fgsel {} option
• some tabs are marked with magenta foreground, meaning "modified" or similar

Here the details are:

• bartabs got -imagemark option, so the tabs are marked with an image
• if not marked or hovered, the tabs can show its own images

Here the details are:

• tabs can be multi-selected with Ctrl+Click
• thus, the caller of bartabs can handle the batch of tabs

Here the details are:

• handlers can be called using hot keys or a popup menu bound to bartabs
• by default, the menu actions include: 1) choosing a tab 2) moving a tab 3) closing tab(s)
• the list of tabs contains three separated tab lists: the invisible at left, the visible, the invisible at right
• a tab can be moved with drag-and-drop or with "... behind" menu action
• static (-static yes) bartabs has no actions except for choosing a tab
• even for static bartabs, its caller can provide additional menu actions and submenus

The commands to call bartabs are as simple as:

after idle [list NS::fillBar $wframe]

after 10 [list NS::fillBar $wframe]

update
NS::fillBar $wframe

• NS::fillBar is a caller that should create a bar of tabs and call a method of bartabs to show the bar; there are a few of such methods
• wframe is a path to a parent widget that should hold bartabs, most likely a frame

However, before calling any NS::fillBar it's necessary to create bartabs::Bars object, one for all possible bars:

bartabs::Bars create NS::bars

The NS::fillBar usually contains a code similar to:

# make a list of main options
set barOptions [list -wbar $wframe -wbase .somepath \
  -csel {NS::selTab %t} -cdel {NS::delTab %t} \
  -menu [list sep "com {New tab...} {NS::addTab %b}"]

# add tabs' labels
foreach lbl $labels {lappend barOptions -tab $lbl}

# create the bar
NS::bars create NS::bar $barOptions

# show the bar with $label1 as a current tab
set TID [NS::bar tabID $label1]
NS::bar $TID show

NS::bars destroy

The details about all these Bars, NS::bars, TID etc. are considered below.

For the full list of bartabs interface methods and their sources, please refer to Reference.

The bartabs defines three TclOO classes:

• Tab deals with tabs
• Bar deals with a bar of tabs
• Bars deals with bars of tabs

However, only the Bars class is used to create bars along with tabs. It can be also used to deal with any bars and tabs, providing all necessary interface.

The Bar does not create a real TclOO object, rather it is sort of syntax sugar for a convenient access to the bar methods. An application can create and handle as many bars as required.

The Tab does not create a real TclOO object as well. It serves actually for structuring bartabs code as for tab methods. Thus, its methods are accessible through the bars ("real" TclOO) and bar ("sugar") objects.

A common work flow with bartabs looks like this:

1) Firstly, we create a bartabs::Bars object, e.g.

bartabs::Bars create NS::bars

2) Then we create a bar object passing it a list of bar options, e.g.

NS::bars create NS::bar $barOptions

3) At last, we show the bar and select a tab as the current:

set TID [NS::bar tabID "tab label"]  ;# get a tab's ID by its label
NS::bar $TID show                    ;# show the bar and select the tab

or just draw the bar without mind-breaking about its tabs:

NS::bar draw    ;# show the bar without selecting a tab

4) The rest actions include:

• responses to a selection of tab (through -csel command option of Bar object)
• responses to a deletion (closing) of tab (through -cdel / -cdel2 command option of Bar object)
• responses to a reorganization of bar (through -cmov / -cmov2 / -cmov3 command option of Bar object)
• inserting and renaming tabs
• disabling and enabling tabs
• marking tabs with colors or icons
• processing the marked tabs
• processing multiple tabs selected with Ctrl+click
• scrolling tabs to left/right through key bindings
• calling other handlers through key bindings and bartabs menu
• using cget and configure methods to change the bar/tab appearance
• redrawing bars at some events
• removing and creating as much bars as required

Few words about BID and TID mentioned throughout the bartabs.

These are identifiers of bars and tabs, of form bar<index> and tab<index> where <index> is an integer increased from 0 in order of bar/tab creation. The bars and the tabs of all bars have unique IDs.

You can use these literals freely, along with BIDs and TIDs gotten from bartabs methods. For example, if you know that "some tab" was created third, you can show it straightforward:

NS::bar tab2 show    ;# show the 3rd tab (TID=tab2)

instead of

NS::bar [NS::bar tabID "some tab"] show    ;# find and show the tab by its name

The "sugariness" of NS::bar consists in its being equivalent to NS::bars $BID, just to save words and avoid typos.

There is also a "sugar" for tabs:

NS::bar create NS::tab "some label"

NS::bar create NS::tabMain "a boss tab"      ;# create a tab object by the tab's label
NS::tabMain configure -text "me the boss"    ;# a new boss enters
NS::tabMain show                             ;# the tab object didn't change its TID
NS::bar create NS::tabMeBoss "me the boss"   ;# it's the same TID
NS::tabMeBoss close                          ;# closes NS::tabMain too

For examples of using tab objects, refer to test.tcl (a line with ::bar1 create ::tab8 and below it).

Note: The tabs can be of the same name only when they belong to different bars. Inside a bar the tabs should have unique names. If some names are going to be equal you can supply them with prefixes or suffixes, sort of "subdir/", "(2)", "(copy 1)" etc. The tabID method helps to get a tab's ID by its label.

Below is a short description of bartabs classes and methods. For more details, please refer to Reference.

bartabs::Tab

The methods of bartabs::Tab class are called from NS::bars or NS::bar object and are passed: tab ID (TID), method name, arguments.

Syntax:

OBJECT TID method arguments

For example:

NS::bars $TID show
NS::bar $TID close

NS::bar create NS::tab "tab label"
NS::tab show
NS::tab close

bartabs::Bar

The methods of bartabs::Bar class are called from NS::bar object or (more wordy) from NS::bars object.

Syntax:

BAR_OBJECT method arguments

BARS_OBJECT BID method arguments

For example:

NS::bar popList $X $Y
NS::bars $BID popList $X $Y

bartabs::Bars

The methods of bartabs::Bars class are applied to all of registered bars.

Syntax:

BARS_OBJECT method arguments

For example:

NS::bars drawAll
NS::bars markTab tab11 tab99

The following conventions are accepted:
  BID means a bar's ID
  TID means a tab's ID
  NS::bars means a bartabs::Bars object created with TclOO
  NS::bar means a bar object created with NS::bars object

Below are listed the options of NS::bar.

-wproc {winfo width .win.mframe.text1}

proc NS::btsWidth {BID w1 w2} {
  # w1, w2 are widgets restricting the bar's width
  set bl [expr {[winfo width $w1]-[winfo width $w2]-40}]
  # a condition could mess up
  if {$NS::condition} {incr bl [$NS::proc $BID]}
  return $bl
}
NS::bars create NS::bar [list -wbar $wbar \
  -wproc [list NS::btsWidth %b $wmain $wleft] -tab Noname]

puts [llength [NS::bar cget -select]]

  -cdel {NS::btsDel %b %t {%l}}
  ...
  proc NS::btsDel {bid tid lab args} {
  ...
  }

  -cmov3 {NS::onMovingTabs %t}

...
-menu [list \
  s \
  "c {Add } {NS::addTab %t} {} ::NS::isDisableTab" \
  {c {View selected} {NS::ViewSelTabs %b}} \
  {c {Unselect all} {NS::UnselectAll %b}} \
  s \
  "m {Options} {} mnusw" \
  "c {Switch -bd} {NS::switchBts %b %t -bd} mnusw {0 imgSW {%l} Ctrl+B}"]
...
proc ::NS::isDisableTab {BID TID label} {
  if {$NS::conditionToDisable} {return 1}
  if {$NS::conditionToHide} {return 2}
  return [list 0 imgOK "$label - OK" Ctrl+Enter]
}

set savedmarks [NS::bar cget -mark]
...
NS::bar configure -mark $savedmarks
NS::bar draw

The NS::bar configure and NS::bar cget methods are used to set and get the bar options. For example, you can run

lassign [NS::bar cget -tleft -tright] tleft tright
...
NS::bar configure -tleft $tleft -tright $tright
NS::bar clear
NS::bar draw

There are also two analogue methods NS::bar TID configure and NS::bar TID cget to set and get the tab options however few they are:

• -text sets a tab label's text
• -tip sets a tab label's tip (overcoming -lablen option)

That said, these methods may be useful to store and fetch your own options, i.e. any data related to your bars and tabs. Sort of little data bases.

For some examples of using bartabs options, please refer to test.tcl of bartabs.zip or test2_pave.tcl of apave package.

At calling bartabs, the calculation of bar width may present a problem. Though, if a bar is created from scratch it may contain a "noname" tab or no tabs at all which would hardly set a problem.

But when the bartabs is called with a batch of tabs e.g. fetched from a previous session, it should be supplied with a maximum of bar width to place the tabs. In general, only a part of tabs can be placed on a bar widget, as its width is usually restricted by another widget, mostly by a contents editor (text, layout, picture, map etc.).

• -wbase sets a path to a widget whose width should restrict the bar width; in most cases its width is equal to the width of the bar
• -wproc sets a procedure that calculates the bar width in more peculiar surroundings

There are few methods to show a bar. What's the best?

NS::tab1 configure -text "Text of tab1"
NS::tab2 configure -text "Text of tab2"
NS::tab1 show yes  ;# "yes" argument means a forced updating

NS::bar clear
NS::bar draw

NS::bar configure -tleft $tleft -tright $tright
NS::bar clear
NS::bar draw

NS::bar configure -static yes
NS::bar update

NS::bar scrollLeft
NS::bar scrollRight