Skip to main content

Some more obscure Text widget commands

This morning I added a few extra commands to the text widget which, are somewhat odd, I admit, but does provide further widget introspection for those who might need it.

text-id getCoords start
text-id getCoords cursor
text-id getCoords {1 0}
text-id getIndex {15 15}
text-id getRect
These commands are derived from the GtkTextView widget rather than GtkTextBuffer and GtkTextIter and so are more focussed on how text is rendered to the display rather than the text content itself. Internally, the Gtk+ keeps track of what is kept in the current text display buffer. Looking at the above examples one can see that getCoord takes as its argument either a text index, ie line 1, row 1 (of the text buffer) or one of several positioning keywords. What is returned is the window x,y pixel coordinates for that position. The opposite effect is produced by getIndex, here 15 15 is the pixel x,y coords whose content we want to determine in terms of its corresponding position in the textBuffer. Finally, getRect returns the window position and size of the rendered region of the text. If a specified position is not in the textView, then a negative value will be returned.

I’ve always found the idea of matched data and display buffers (i.e. a viewport) to be a little hard to work with. When I have the time I’ll create an illustrative diagram.


Comments

Popular posts from this blog

gnocl::calendar

Given this module some attention today. Added some of the more package wide options to the module and created customised handler for setting the month. (For some odd reason months are are counted 0-11 whereas days are 1-31.) There's still a little more to do to this one including the addition of code to store diary details. Here's the working test script to show the range of options at work. The percentage substitution string item %e explores something that I've been toying with, the name of the signal/event that initiated the call. Ok, a script can keep its own internal trace but who knows, it might prove useful. #--------------- # calendarTest.tcl #--------------- # Author:   William J Giddings # Date:     07/05/09 #--------------- #!/bin/sh # the next line restarts using tclsh \ exec tclsh "$0" "$@" #--------------- package require Gnocl set cal [gnocl::calendar] $cal configure -day 8 -month 7 -year 1956 $cal configure -rowHeight 1 -colWidth 1 $ca

Simple Runtime Debugging Message Dialog

At times it's useful to see what values variables hold, or offer some pause point before the code goes elsewhere before causing havoc. Its possible to write output to the terminal but this can get lost in copious forms of other outputs, besides, there's no pausing the script execution either. The following proc creates a custom dialog which displays ad message along with the point in the calling script from which it was invoked. ## simple runtime debugging feedback dialog, alternative to console based gnocl::msg # @param msg message to display # @returns none # proc xxx::msg {txt} { set frame [info frame -1] append msg "Message:\n\n" append msg " $txt \n\n\n" append msg "Called from:\n\n" append msg "Proc:\t[lindex [info level -1] 0]\n" append msg "File:\t[file tail [dict get $frame file]]\n" append msg "Line:\t[dict get $frame line]\n" gnocl::dialog \ -type info \ -text $msg

Creating a button box with right aligned widgets

The dialog widget has its own internal functionaluty to create and position buttons at the bottom right corner of the window container. When creating these for ourselves it must be born in mind that default settings for fill and expand are both 0.5. Failing to set these will always place the child objects in the centre, regardless of alignment. For most cases these defaults are acceptable but, to create that dialog-button arrangement, use the following snippet as a model!   # to right align completely, set expand and fill to 0 set hbox [gnocl::hBox] set b1 [gnocl::button -text Select \                -data $lst                 -onClicked { puts DO-SOMETHING-WITH-%d} ] set b2 [gnocl::button -text Cancel -onClicked { puts DONE! } ] $vbox add $hbox -expand 0 -fill 0 -align right $hbox add $b1 $hbox add $b2