fontchooser
fontchooser
NAMESYNOPSIS
DESCRIPTION
CONFIGURATION OPTIONS
VIRTUAL EVENTS
NOTES
EXAMPLE
SEE ALSO
KEYWORDS
___________________________
NAME
fontchooser − control font selection dialog
SYNOPSIS
tk fontchooser configure ?−option value −option value ...?
tk fontchooser show
tk fontchooser hide ___________________________
DESCRIPTION
The tk fontchooser command controls the Tk font selection dialog. It uses the native platform font selection dialog where available, or a dialog implemented in Tcl otherwise.
Unlike most of the other Tk dialog commands, tk fontchooser does not return an immediate result, as on some platforms (Mac OS X) the standard font dialog is modeless while on others (Windows) it is modal. To accommodate this difference, all user interaction with the dialog will be communicated to the caller via callbacks or virtual events.
The tk
fontchooser command can have one of the following forms:
tk fontchooser configure ?−option value
−option value ...?
Set or query one or more of the configurations options below (analogous to Tk widget configuration).
tk fontchooser show
Show the font selection dialog. Depending on the platform, may return immediately or only once the dialog has been withdrawn.
tk fontchooser hide
Hide the font selection dialog if it is visible and cause any pending tk fontchooser show command to return.
CONFIGURATION OPTIONS
−parent
Specifies/returns the logical parent window of the font selection dialog (similar to the −parent option to other dialogs). The font selection dialog is hidden if it is visible when the parent window is destroyed.
|
−title |
Specifies/returns the title of the dialog. Has no effect on platforms where the font selection dialog does not support titles. | ||
|
−font |
Specifies/returns the font that is currently selected in the dialog if it is visible, or that will be initially selected when the dialog is shown (if supported by the platform). Can be set to the empty string to indicate that no font should be selected. Fonts can be specified in any form given by the "FONT DESCRIPTION" section in the font manual page. |
−command
Specifies/returns the command prefix to be called when a font selection has been made by the user. The command prefix is evaluated at the global level after having the specification of the selected font appended. On platforms where the font selection dialog offers the user control of further font attributes (such as color), additional key/value pairs may be appended before evaluation. Can be set to the empty string to indicate that no callback should be invoked. Fonts are specified by a list of form [3] of the "FONT DESCRIPTION" section in the font manual page (i.e. a list of the form {family size style ?style ...?}).
−visible
Read-only option that returns a boolean indicating whether the font selection dialog is currently visible. Attempting to set this option results in an error.
VIRTUAL EVENTS
<<TkFontchooserVisibility>>
Sent to the dialog parent whenever the visibility of the font selection dialog changes, both as a result of user action (e.g. disposing of the dialog via OK/Cancel button or close box) and of the tk fontchooser show/hide commands being called. Binding scripts can determine the current visibility of the dialog by querying the −visible configuration option.
<<TkFontchooserFontChanged>>
Sent to the dialog parent whenever the font selection dialog is visible and the selected font changes, both as a result of user action and of the −font configuration option being set. Binding scripts can determine the currently selected font by querying the −font configuration option.
NOTES
Callers should not expect a result from tk fontchooser show and may not assume that the dialog has been withdrawn or closed when the command returns. All user interaction with the dialog is communicated to the caller via the −command callback and the <<TkFontchooser*>> virtual events. It is implementation dependent which exact user actions result in the callback being called resp. the virtual events being sent. Where an Apply or OK button is present in the dialog, that button will trigger the −command callback and <<TkFontchooserFontChanged>> virtual event. On some implementations other user actions may also have that effect; on Mac OS X for instance, the standard font selection dialog immediately reflects all user choices to the caller.
In the presence of multiple widgets intended to be influenced by the font selection dialog, care needs to be taken to correctly handle focus changes: the font selected in the dialog should always match the current font of the widget with the focus, and the −command callback should only act on the widget with the focus. The recommended practice is to set font dialog −font and −command configuration options in per−widget <FocusIn> handlers (and if necessary to unset them − i.e. set to the empty string − in corresponding <FocusOut> handlers). This is particularly important for implementers of library code using the font selection dialog, to avoid conflicting with application code that may also want to use the dialog.
Because the font selection dialog is application-global, in the presence of multiple interpreters calling tk fontchooser, only the −command callback set by the interpreter that most recently called tk fontchooser configure or tk fontchooser show will be invoked in response to user action and only the −parent set by that interpreter will receive <<TkFontchooser*>> virtual events.
The font dialog implementation may only store (and return) font actual data as the value of the −font configuration option. This can be an issue when −font is set to a named font, if that font is subsequently changed, the font dialog −font option needs to be set again to ensure its selected font matches the new value of the named font.
EXAMPLE
proc
fontchooserDemo {} {
wm title . "Font Chooser Demo"
tk fontchooser configure −parent .
button .b −command fontchooserToggle −takefocus
0
fontchooserVisibility .b
bind . <<TkFontchooserVisibility>> \
[list fontchooserVisibility .b]
foreach w {.t1 .t2} {
text $w −width 20 −height 4 −borderwidth 1
−relief solid
bind $w <FocusIn> [list fontchooserFocus $w]
$w insert end "Text Widget $w"
}
.t1 configure −font {Courier 14}
.t2 configure −font {Times 16}
pack .b .t1 .t2; focus .t1
}
proc fontchooserToggle {} {
tk fontchooser [expr {
[tk fontchooser configure −visible] ?
"hide" : "show"}]
}
proc fontchooserVisibility {w} {
$w configure −text [expr {
[tk fontchooser configure −visible] ?
"Hide Font Dialog" : "Show Font
Dialog"}]
}
proc fontchooserFocus {w} {
tk fontchooser configure −font [$w cget
−font] \
−command [list fontchooserFontSelection $w]
}
proc fontchooserFontSelection {w font args} {
$w configure −font [font actual $font]
}
fontchooserDemo
SEE ALSO
KEYWORDS
dialog, font, font selection, font chooser, font panel
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
