tk examples

8/13/2019 Tk Examples

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## From Chapter 2# Bad Window example#################################################################!/usr/bin/perl -wuse Tk;

my $mw = MainWindow->new;$mw->title("Bad Window");$mw->Label(-text => "This is an example of a window that looks bad\nwhenyou don't send any options to pack")->pack;

$mw->Checkbutton(-text => "I like it!")->pack;$mw->Checkbutton(-text => "I hate it!")->pack;$mw->Checkbutton(-text => "I don't care")->pack;$mw->Button(-text => "Exit", -command => sub { exit })->pack;MainLoop;

################################################################# Good Window example#################################################################!/usr/bin/perl -wuse Tk;

my $mw = MainWindow->new;$mw->title("Good Window");$mw->Label(-text => "This window looks much more organized, and lesshaphazard\nbecause we used some options to make it look nice")->pack;

$mw->Button(-text => "Exit", -command => sub { exit })->pack(-side => 'bottom',

-expand => 1, -fill => 'x');$mw->Checkbutton(-text => "I like it!")->pack(-side => 'left', -expand => 1);$mw->Checkbutton(-text => "I hate it!")->pack(-side => 'left',

-expand => 1);

$mw->Checkbutton(-text => "I don't care")->pack(-side => 'left', -expand => 1);MainLoop;

################################################################## From Chapter 3: Code to read in the names of the cursors and allow## you to see what they look like using a listbox#################################################################!/usr/bin/perl -wuse Tk;

## Create elements of window$mw = MainWindow->new;

$mw->Button(-text => "Exit",-command => sub { exit })->pack(-side => "bottom", -fill => "x");$scroll = $mw->Scrollbar;$lb = $mw->Listbox(-selectmode => 'single', -yscrollcommand => [set => $scroll]);$scroll->configure(-command => [yview => $lb]);

$scroll->pack(-side => 'right', -fill => 'y');$lb->pack(-side => 'left', -fill => 'both');


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## Open file that contains all available cursors## Might have to change this if your cursorfont.h is elsewhere## On Win32 systems look in C:\Perl\lib\site\Tk\X11\cursorfont.hopen (FH, "/usr/X11R6/include/X11/cursorfont.h") || die "Couldn't open cursor file.\n";

while () { push(@cursors, $1) if (/\#define XC_(\w+) /);}

close(FH);

$lb->insert('end', sort @cursors);$lb->bind('',

sub { $mw->configure(-cursor => $lb->get($lb->curselection)); });

MainLoop;

################################################################## Help Label example################################################################$mw = MainWindow->new;$mw->title("Help Label Example");

$mw->Label(-textvariable => \$message) ->pack(-side => 'bottom', -fill => 'x');

$b = $mw->Button(-text => "Exit", -command => \&exit) ->pack(-side => 'left');&bind_message($b, "Press to quit the application");

$b2 = $mw->Button(-text => "Do Nothing")->pack(-side => 'left');&bind_message($b2, "This button does absolutely nothing!");

$b3 = $mw->Button(-text => "Something", -command => sub { print"something\n"; })->pack(-side => 'left');

&bind_message($b3, "Prints the text 'something'");sub bind_message { my ($widget, $msg) = @_; $widget->bind('', [ sub { $message = $_[1]; }, $msg ]); $widget->bind('', sub { $message = ""; });}

MainLoop;

################################################################## Incrementing entry widget################################################################

#!/usr/bin/perluse Tk;$mw = MainWindow->new;$mw->title("Entry");

$e_txt = "Entry Text"; # Create entry with initial text$e = $mw->Entry(-textvariable => \$e_txt)->pack(-expand => 1, -fill => 'x');$mw->Button(-text => "Exit", -command => sub { exit })->pack(-side => 'bottom');


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# Create a Button that will insert a counter at the cursor$i = 1;$mw->Button(-text => "Insert #", -command =>

sub {if ($e->selectionPresent()) {

$e->insert('sel.last', "$i"); $i++; } })->pack;MainLoop;

################################################################## From Chapter 6 - Scrolling more than one listbox with one scrollbar################################################################use Tk;

$mw = MainWindow->new();$mw->title("One Scrollbar/Three Listboxes");$mw->Button(-text => "Exit",

-command => sub { exit })->pack(-side => 'bottom');

$scroll = $mw->Scrollbar();# Anonymous array of the three listboxes$listboxes = [ $mw->Listbox(), $mw->Listbox(), $mw->Listbox() ];

# This method is called when one listbox is scrolled with the keyboard# It makes the scrollbar reflect the change, and scrolls the other listssub scroll_listboxes { my ($sb, $scrolled, $lbs, @args) = @_; $sb->set(@args); my ($top, $bottom) = $scrolled->yview(); foreach $list (@$lbs) { $list->yviewMoveto($top); }}

# Configure each listbox to call &scroll_listboxes

foreach $list (@$listboxes) { $list->configure(-yscrollcommand => [ \&scroll_listboxes, $scroll, $list, $listboxes ]);}

# Configure the scrollbar to scroll each listbox$scroll->configure(-command => sub { foreach $list (@$listboxes) { $list->yview(@_); }});

# Pack the scrollbar and listboxes$scroll->pack(-side => 'left', -fill => 'y');foreach $list (@$listboxes) {

$list->pack(-side => 'left'); $list->insert('end', "one", "two", "three", "four", "five", "six","seven", "eight", "nine", "ten", "eleven");

}

MainLoop;

################################################################## From Chapter 7: Searching through a listbox################################################################


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use Tk;

$mw = MainWindow->new;$mw->title("Listbox");# For example purposes, we'll use one word for each letter@choices = qw/alpha beta charlie delta echo foxtrot golf hotel india juliet kilo lima motel nancy oscar papa quebec radio sierra tango uniform victor whiskey xray yankee zulu/;

# Create the entry widget, and bind the do_search sub to any keypress$entry = $mw->Entry(-textvariable => \$search)->pack(-side => "top",

-fill => 'x');$entry->bind('', [ \&do_search, Ev('K') ]);

# Create listbox and insert the list of choices into itmy $lb = $mw->Scrolled('Listbox', -scrollbars => "osoe",

)->pack(-side => 'left');$lb->insert('end', sort @choices);

$mw->Button(-text => "Exit",-command => sub { exit; })->pack(-side => 'bottom');

MainLoop;

# This routine is called each time we push a keyboard key.sub do_search { my ($entry, $key) = @_;

# Ignore the backspace key and anything that doesn't change the word # i.e. The Control or Alt keys

return if ($key =~ /backspace/i); return if ($oldsearch eq $search);

# Use what's currently displayed in listbox to search through# This is a non-complicated in order search

my @list = $lb->get(0, 'end'); foreach (0 .. $#list) {

if ($list[$_] =~ /^$search/) { $lb->see($_); $lb->selectionClear(0, 'end'); $lb->selectionSet($_); last; } } $oldsearch = $search;}

################################################################

## From Chapter 8: Text Widget## Loads/edits/saves files using text widget################################################################use Tk;$mw = MainWindow->new;# Create necessary widgets$f = $mw->Frame->pack(-side => 'top', -fill => 'x');$f->Label(-text => "Filename:")->pack(-side => 'left', -anchor => 'w');$f->Entry(-textvariable => \$filename)->pack(-side => 'left',

-anchor => 'w', -fill => 'x', -expand => 1);


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$f->Button(-text => "Exit", -command => sub { exit; } )-> pack(-side => 'right');$f->Button(-text => "Save", -command => \&save_file)-> pack(-side => 'right', -anchor => 'e');$f->Button(-text => "Load", -command => \&load_file)-> pack(-side => 'right', -anchor => 'e');$mw->Label(-textvariable => \$info, -relief => 'ridge')-> pack(-side => 'bottom', -fill => 'x');$t = $mw->Scrolled("Text")->pack(-side => 'bottom',

-fill => 'both', -expand => 1);

MainLoop;

# load_file checks to see what the filename is and loads it if possiblesub load_file { $info = "Loading file '$filename'..."; $t->delete("1.0", "end"); if (!open(FH, "$filename")) { $t->insert("end", "ERROR: Could not open $filename\n");

return;}

while () { $t->insert("end", $_); } close (FH); $info = "File '$filename' loaded";

}# save_file saves the file using the filename in the entry box.sub save_file { $info = "Saving '$filename'"; open (FH, ">$filename"); print FH $t->get("1.0", "end"); $info = "Saved.";}

################################################################## From Chapter 8: Text## Example of embedding widgets in a Text Widget

################################################################use Tk;

$mw = MainWindow->new;$mw->title("Data Entry");$f = $mw->Frame->pack(-side => 'bottom');$f->Button(-text => "Exit",

-command => sub { exit; })->pack(-side => 'left');$f->Button(-text => "Save", -command => sub { # do something with %info;

})->pack(-side => 'bottom');$t = $mw->Scrolled("Text", -width => 40,

-wrap => 'none')->pack(-expand => 1, -fill => 'both');

foreach (qw/Name Address City State Zip Phone OccupationCompany Business_Address Business_Phone/) {

$w = $t->Label(-text => "$_:", -relief => 'groove', -width => 20);$t->windowCreate('end', -window => $w);$w = $t->Entry(-width => 20, -textvariable => \$info{$_});$t->windowCreate('end', -window => $w);$t->insert('end', "\n");

}$t->configure(-state => 'disabled');


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MainLoop;

################################################################## From Chapter 9: Canvas Widget## Quick Draw using canvas################################################################use Tk;

$mw = MainWindow->new;$mw->title("Quick Draw");

$f = $mw->Frame(-relief => 'groove',-bd => 2,-label => "Draw:")->pack(-side => 'left', -fill => 'y');

$draw_item = "rectangle";$f->Radiobutton(-variable => \$draw_item, -text => "Rectangle", -value => "rectangle", -command => \&bind_start)->pack(-anchor => 'w');$f->Radiobutton(-variable => \$draw_item, -text => "Oval", -value => "oval", -command => \&bind_start)->pack(-anchor => 'w');$f->Radiobutton(-variable => \$draw_item,

-text => "Line", -value => "line", -command => \&bind_start)->pack(-anchor => 'w');$f->Label(-text => "Line Width:")->pack(-anchor => 'w');$thickness = 1;$f->Entry(-textvariable => \$thickness)->pack(-anchor => 'w');

$c = $mw->Scrolled("Canvas", -cursor => "crosshair")->pack( -side => "left", -fill => 'both', -expand => 1);$canvas = $c->Subwidget("canvas");

&bind_start();

MainLoop;sub bind_start { # If there is a "Motion" binding, we need to allow the user # to finish drawing the item before rebinding Button-1 # this fcn gets called when the finish drawing the item again @bindings = $canvas->Tk::bind(""); return if ($#bindings >= 0);

if ($draw_item eq "rectangle") { $canvas->Tk::bind("", [\&start_drawing, Ev('x'), Ev('y')]); } elsif ($draw_item eq "oval") { $canvas->Tk::bind("", [\&start_drawing, Ev('x'), Ev('y')]);

} elsif ($draw_item eq "line") { $canvas->Tk::bind("", [\&start_drawing, Ev('x'), Ev('y')]); }}

sub start_drawing { my ($canv, $x, $y) = @_; $x = $canv->canvasx($x); $y = $canv->canvasy($y);


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# Do a little error checking $thickness = 1 if ($thickness !~ /[0-9]+/);

if ($draw_item eq "rectangle") { $canvas->createRectangle($x, $y, $x, $y,

-width => $thickness, -tags => "drawmenow"); } elsif ($draw_item eq "oval") { $canvas->createOval($x, $y, $x, $y, -width => $thickness, -tags => "drawmenow"); } elsif ($draw_item eq "line") { $canvas->createLine($x, $y, $x, $y,

-width => $thickness, -tags => "drawmenow"); }

$startx = $x; $starty = $y; # Map the Button-1 binding to &end_drawing instead of start drawing $canvas->Tk::bind("", [\&size_item, Ev('x'), Ev('y')]); $canvas->Tk::bind("", [\&end_drawing, Ev('x'), Ev('y')]);}

sub size_item { my ($canv, $x, $y) = @_; $x = $canv->canvasx($x); $y = $canv->canvasy($y);

$canvas->coords("drawmenow", $startx, $starty, $x, $y);}

sub end_drawing { my ($canv, $x, $y) = @_; $x = $canv->canvasx($x); $y = $canv->canvasy($y);

# finalize the size of the item, and remove the tag from the item $canvas->coords("drawmenow", $startx, $starty, $x, $y); $canvas->dtag("drawmenow");

# remove motion binding. $canvas->Tk::bind("", ""); &bind_start();}

################################################################## Creating radiobuttons#################################################################!/usr/bin/perl -w

use Tk;my $mw = MainWindow->new;$mw->title("Menubutton");

$menub = $mw->Menubutton(-text => "Color")->pack(-side => 'left', -anchor => 'n');foreach (qw/red yellow green blue grey/) { $menub->radiobutton(-label => $_, -command => \&set_bg, -variable => \$background_color, -value => $_);}

MainLoop;


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sub set_bg { print "Background value is now: $background_color\n"; $mw->configure(-background => $background_color);}

################################################################# Cascade menu example#################################################################!/usr/bin/perl -wuse Tk;my $mw = MainWindow->new;$mw->title("Menubutton");# Create menubutton and put on the screen$menub = $mw->Menubutton(-text => "Menubutton")->pack;

# make our sub menu to be cascaded a child of upper menu.$menu1 = $menub->menu->Menu;foreach (qw/one two three four/) { $menu1->add('command', -label => $_);}

# make second sub menu also a child of the upper menu$menu2 = $menub->menu->Menu;

foreach (qw/A B C D/) { $menu2->radiobutton(-label => $_);}

# now add the cascade items to the main menu$menub->cascade(-label => "Numbers");$menub->cascade(-label => "Letters");

# now configure those cascade entries to point to correct submenu$menub->entryconfigure("Numbers", -menu => $menu1);$menub->entryconfigure("Letters", -menu => $menu2);

MainLoop;

################################################################## Using Menubuttons to create a menubar example#################################################################!/usr/bin/perl -wuse Tk;my $mw = MainWindow->new;$mw->title("Menubutton");

$mw->Button(-text => "Exit", -command => sub { exit; })->pack(-side => "bottom");

my $f = $mw->Frame(-relief => 'ridge', -bd => 2);$f->pack(-side => 'top', -anchor => 'n', -expand => 1, -fill => 'x');

foreach (qw/File Edit Options Help/) { push (@menus, $f->Menubutton(-text => $_));}

$menus[3]->pack(-side => 'right');$menus[0]->pack(-side => 'left');


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$menus[1]->pack(-side => 'left');$menus[2]->pack(-side => 'left');

MainLoop;

################################################################## Example from Chapter 11: Menus## Dynamic document list in a menu################################################################

#!/usr/bin/perl -w

use Tk;$mw = MainWindow->new;$mw->title("Documents");

# Create a frame for our 'menubar' across the top of the window$f = $mw->Frame(-relief => 'ridge', -bd => 2) ->pack(-side => 'top', -anchor => 'n', -expand => 1, -fill => 'x');

# Create the menubutton, with two items: New Doc and a separator$filem = $f->Menubutton(-text => "File", -tearoff => 0, -menuitems => [ ["command" => "New Document",

-command => \&new_document], "-" ])->pack(-side => 'left');# We will open document 1 to begin with, and we want to limit the number# of documents in our list to 0-9 (leaves 10 docs max in menu)$doc_num = 1;$doc_list_limit = 9;

# Create button that will do the same thing as the New Document menu item$mw->Button(-text => "New Document", -command => \&new_document)->pack(-side => 'bottom', -anchor => 'e');# The entry will display the current doc we are "editing".

$entry = $mw->Entry(-width => 80)->pack(-expand => 1, -fill => 'both');MainLoop;

# Creates the next doc in line, incs the doc counter# Adds the new doc to the menu, and removes any docs from the# menu that are over the limit (oldest out first)sub new_document { my $name = "Document $doc_num"; $doc_num++;

push (@current, $name); $filem->command(-label => "$name",

-command => [ \&select_document, $name ]); &select_document($name);

if ($#current > $doc_list_limit) {

$filem->menu->delete(2); shift(@current); }}


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sub select_document { my ($selected) = @_;

$entry->delete(0, 'end'); $entry->insert('end', "SELECTED DOCUMENT: $selected");}