Learning Perl/Tk
by Nancy Walsh

Here are the changes that were made in the 3/99 reprint:


(1) Added text to footnote. The text used to read:

	"Unless you get the Win32 binary from CPAN"

It now reads:

	"Unless you get the Win32 binary from CPAN or another pre-built
	distribution such as ActiveState Perl"


{7} In code snippet near bottom of page, the line used to read:

	$mw = new MainWindow; # or $mw = MainWindow => new();
	$top = $mw -> Toplevel();
	$frame = $mw -> Frame (-borderwidth => 2, -relief => "groove");

Now reads:

	$mw = new MainWindow; # or $mw = MainWindow->new();
	$top = $mw->Toplevel();
	$frame = $mw->Frame(-borderwidth => 2, -relief => "groove");

Removed spaces as indicated in each line, and changed => to a -> in the first
line.



(8) Paragraph 4, before 2nd code snippet.  Last sentence used to read:

	"... on its own separate line, after the last option/value pair:"

Changed to:

	"... on its own separate line, after the last option/value pair, which
	 retains the comma for formatting ease:"

(8) In the next paragraph this text:

	"... without having to mess with parentheses and semicolons."

Was changed to:

	"... without having to mess with parentheses, semicolons or commas."


<9> Second code snippet on the page used to read:

	$button -> pack();

Removed spaces so that it reads like this:

	$button->pack();


<11> On very first line of this page, deleted the comma so the text now reads:

	"... our window say "Hello World" and create a button ..."


{11} Added quotes in the fourth line of sample code, it now reads:

        $mw->title("Hello World");


<17> The second usage statement for pack used to read:

	$widget->pack( [ option => value,  ] );

Inserted ellipses to indicate additional possible options:

	$widget->pack( [ option => value, ... ] );
                                       ^^^^^

{17} In code segment, added a quotation mark:

	don't send any options to pack


{35} Added ellipses to first code snippet. It now reads:

	$widget1->grid( [ $widget2, ... , ] [ option => value, ... ] );


{35} Second paragraph. Second sentence used to read:

	You can also invoke grid() on each window independently ...

Changed to:

	You can also invoke grid() on each widget independently ...

	                                   ^^^^^^
{58} In Button Options section, the -anchor option, bolded the 'center'
     option to show that it is the default.


(58) Under -borderwidth option, the second line, the word -relief
     was spaced widely. Tightened text.


(59) Under -highlightbackground option (2nd on page), the text used to read:

	Sets the color of a nonfocus rectangle.

Changed to:

	Sets the color of the area behind the focus rectangle (shows
	when widget does not have focus).


<59> Under -justify, text used to read:

	Sets the side of the button against which the text will justify itself.

Changed to:

	Sets the side of the button against which multiline text will justify
        itself.


{59} As part of -relief option, added the -solid option.  Now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


{62} The example for creating an anonymous sub showed the following code:

	sub { # do something }

Changed to:

	sub { .. do something .. }
		  ^^^^^^^^^^^^^^^^^^
And made all indicated by ^^^ above in italics

<65> Changed Figure 3-4 so that the second button's text is "Enable Exit," not
       "Disable Exit."


{68} Last line on page, added 'solid'. Text now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


<75> Changed Figure 3-18 so that the second button's text is "Enable Exit," not
       "Disable Exit."


<78> Inserted footnote, placed * in the first sentence on page:

	"The highlight rectangle* is normally displayed..."
	                        ^

Inserted this footnote:

	*On Win32 systems, the highlight rectangle is drawn as a dashed line
	within the widget.

<78> Deleted the sentence before figure 3-22 that said:

	(Both buttons in Figure 3-22 have a -highlightthickness of 10)


{85} Added 'solid' to the -relief option.  Text now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'

(85) Under -selectimage option, the text used to read:

	"Indicates whether image is displayed instead of text ... "

Changed to:

	"Indicates the image to display intead of text..."

{91} In Checkbutton Style section now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


{97} The -relief option now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


{110} First line of code snippet on the page now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


<113> Added quotes to list of index types.  The text used to read:

	anchor

Changed to:

	'anchor'

Last index type, end heading. Used to read:

	end

Changed to:

	'end'


(119) Last code snippet on the page used to read:

	$entry->index(index);

Changed to:

	$numindex = $entry->index(index);


<129> First paragraph, 4th line down.  Text used to read:

	"... -yscrollcommand option has the set command and our scrollbar..."
                                          ^^^
Left wording the same, but put the word 'set' in courier font.


{130} In -relief option, added 'solid.' Text now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


<133> First code snippet on the page reads:

	$scrollbar->configure(-command => ['yview' => $lb]);
                             ^^^^^^^
The word -command is italicized, made it normal courier font.


<133> In code heading of xviewMoveto and yviewMoveto:

	$widget->xviewMoveto(fraction); # or
	$widget->yviewMoveto(fraction);

Changed the word 'fraction' in both lines to italics, indicating an argument
to be replaced.


<137> First paragraph, second sentence reads:

	"... three possible results from fraction: 0.0..."
                                       ^^^^^^^^
The work 'fraction' was in italics but isn't anymore (it is the name of an
actual method).


(141) The code snippet once read:

	$lb = $parent->Listbox( options ...)->pack;

Changed to:

	$lb = $parent->Listbox( [ options ...] )->pack;
                              ^^^^^^^^^^^^^^
marked with ^^ is italics.


<142> First complete sentence on the page:

	"... to use the insert method to insert items into it:"
                                       ^^^^^^

The second insert was courier font, the first one is now instead:

	"... to use the insert method to insert items into it:"
                      ^^^^^^


{143} In the -relief option; added 'solid.' Text now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


{156} Added 'solid' to the -relief option:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


<160> In code snippet, second line used to read:

	... #ts at 1 inch, 1.5 inch and every _ inch after
                                            ^
Took out spaces.


{166} In first code example, the first line used to read:

	$t->Text()->pack();

Changed to:

	$t = $mw->Text()->pack();


{172} In the 'Deleting Text' paragraph, last sentence:

	$text->delete(0, 'end')
                   ^^^^
Changed to:

	$text->delete("1.0", 'end')


{184} Second code snippet, used to read:

	$canvas = $mw->Scrolled("canvas");

Uppercased the c in the quoted word:

	$canvas = $mw->Scrolled("Canvas");
                               ^

{184} Third code snippet, same problem. Changed

	$c = $mw->Scrolled("canvas")->pack;

to:

	$c = $mw->Scrolled("Canvas")->pack;
                          ^

{187} Added 'solid' to the -relief option. Text now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


{188} First paragraph, last sentence used to read:

	"...the tag or ID is the one returned from the ..."

Changed to:

	"...the ID is what is returned from the ..."


{189} Under -start option, second sentence used to read:

	"... is at three o'clock (8 degrees)."

Changed the 8 to a 0:

	"... is at three o'clock (0 degrees)."


{197} In fourth paragraph, first sentence used to read:

	"... by using selectAdjust: $canvas->select("adjust", ..."

Changed to:

	"... by using selectAdjust: $canvas->selectAdjust(..."
                                             ^^^^^^^^^

{198} Code snippet, first line used to read:

    $canvas->createWindow(0,0, $canvas->Button(-text => "Button",

Added the -window option by changing to:

    $canvas->createWindow(0,0, -window => $canvas->Button(-text => "Button",


(200) Second paragraph, second sentence used to read:

	Items added to the canvas after the "all" tag is called will not...

Changed to:

	Items added to the canvas after the call to addtag will not...
                                      ^^^^^^^^^^^^^^^^^^^
Make 'addtag' courier font.


{207} In the drawing program example in sub bind_start the test used to read:

	if ($draw_item eq "rectangle"||#draw_item eq "oval"||.....

It now reads:

	if ($draw_item eq "rectangle"||$draw_item eq "oval"||....


{212} Added 'solid' to -relief option.  Text now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


<249>  The first line after the code example used to read:

	 "In this example, the written words are displayed in the menu (and are
	 stored in $textvariable)..."

It now reads:

	"In this example, the written words are displayed in the menu (and are
 	stored in $displayed)..."


{253} Added 'solid' to the -relief option:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


{259} Added 'solid' to the -relief option. Text now reads:

	-relief => 'flat' | 'groove' | 'raised' | 'ridge' | 'sunken' | 'solid'


{280} The second line in first code snippet used to read:

	# prints this: Tk::Button.button.all

The spaces were missing. Changed to:

	# prints this: Tk::Button .button . all

{280} The fourth line in first code snippet used to read:

	# prints this: MainWindow.all

The spaces were missing.  Changed to:

	# prints this: MainWindow . all


{304} Last sentence on page used to read:

	"...until a variable is set, call waitVariable:"

Changed to:

	"...until a variable's value is changed, call waitVariable:"
                         ^^^^^^^^^^^

{305} Text at top of page used to read:

	The value of $var must be undefined before you call waitVariable and
	processing will resume as soon as $var is defined.

Changed to:

	Processing will continue as soon as the value contained within $var is
	changed to something different.


(311)	Added text in "The cget Method" section:

	"It only returns the current value of the option..."

Changed to:

	"It only returns the current value (or address if the option stores a
	reference) of the option..."