Perhaps rather unwisely, I decided to use
wxPerl for my final year project. (Having said that, from the tutorial at YAPC::Europe 2001, Tk didn't look like a picnic either!). I started out trying to learn wxPerl by reading
Jouke's Perl.com wxPerl tutorial, and that was good--but of course, I need a
lot more. The only GUI programming I've done previously is *cough* VB *cough* and suffice it to say, a fully programmatic GUI like wxPerl is hugely different. I've looked at the various wxPerl tutorials on PerlMonks -
wxPerl tutorial 3 --,
wxPerl Tutorial one :: The basics, and while the former even describes trees (my main problem at the minute), it's not really in the right context.
Anyway, I am creating a music organiser application. The general design is that there will be variable-width "split" at the left hand side of the window which will display the user's music collection as a tree structure. At the minute, my program creates a window, menus and is split into two using Wx::SplitterWindow. Each of the split canvases is a Wx::ScrolledWindow.
Generally, I don't really understand how wxPerl operates. What I understand is that you must, at the very least, extend Wx::Frame and Wx::App and provide an OnInit method for Wx::App. That's fine, I can understand that, and I can understand wx's event model. I can understand creating menus, and that seems relatively straightforward.
What I don't understand is how to create other controls inside the different canvases. When I look at the documentation for the C++ version of wx, I see that when I create a control, I need to specify a parent. As far as I know, this can be any class derived from Wx::Window. However, some of the example wxPerl programs (from which I've learnt most of what I know about wx!) seem to suggest that objects derived from Wx::Window have a method called "add" or similar that can be used to add controls to windows or canvases. However, Wx::ScrolledWindow doesn't seem to support this.
In the code below, when I've created a tree, I've specified $lcanvas, a reference to the left hand canvas, as the parent. If I change this to $self (the window or frame?), the window isn't split properly and only a small rectangular region is displayed. So, my main questions are:
- How can I add a tree to the left-hand part/canvas of the window?
- How can I generally add controls to frames?
- How can I create multiple frames for my application? How can I load and unload them?
#!/usr/bin/perl
use strict;
use Wx;
package MyCanvas;
use strict;
use vars qw(@ISA);
@ISA = qw(Wx::ScrolledWindow);
sub new {
my( $class ) = shift;
my( $this ) = $class->SUPER::new( @_[0,1,2,3], 0, $_[4] );
return $this;
}
package MusicOrganiserSplitterWindow;
use strict;
use vars qw(@ISA);
@ISA = qw(Wx::SplitterWindow);
use Wx qw(:splitterwindow wxDefaultPosition wxDefaultSize);
use Wx::Event qw(EVT_SPLITTER_SASH_POS_CHANGED);
sub new {
my( $class ) = shift;
my( $this ) = $class->SUPER::new( @_, wxDefaultPosition, wxDefaultSi
+ze,
wxSP_3D|wxSP_LIVE_UPDATE );
$this->{FRAME} = $_[0];
return $this;
}
# Extend Wx's "Frame" class to create the main window.
package MusicOrganiserFrame;
use base qw(Wx::Frame);
use Wx qw(wxOK wxICON_INFORMATION wxDefaultPosition wxDefaultSize);
use Wx::Event qw(EVT_MENU);
sub new {
my $class = shift;
my $self = $class->SUPER::new(@_); # Call superclass' constructor
# Assign ID values
my ($ID_MENU_FILE_REPORT, $ID_MENU_FILE_STATISTICS, $ID_MENU_EDIT_AD
+D,
$ID_MENU_EDIT_DELETE, $ID_MENU_TOOLS_SETUP, $ID_MENU_HELP_CONTEN
+TS,
$ID_MENU_HELP_ABOUT, $ID_MENU_FILE_EXIT) = (1 .. 100);
# Create menu objects
my $file_menu = Wx::Menu->new();
my $tools_menu = Wx::Menu->new();
my $edit_menu = Wx::Menu->new();
my $help_menu = Wx::Menu->new();
# Create File menu
$file_menu->Append($ID_MENU_FILE_REPORT, "\&Report\tCtrl+R",
"Produce reports about your collection.");
$file_menu->Append($ID_MENU_FILE_STATISTICS, "\&Statistics\tCtrl+S",
+
"Display statistics for part or all of your collection.");
$file_menu->AppendSeparator();
$file_menu->Append($ID_MENU_FILE_EXIT, "E\&xit\tCtrl+Q");
# Create Edit menu
$edit_menu->Append($ID_MENU_EDIT_ADD, "\&Add volume",
"Add a volume to your collection.");
$edit_menu->Append($ID_MENU_EDIT_DELETE, "\&Delete volume",
"Delete a volume from your collection.");
# Create Tools menu
$tools_menu->Append($ID_MENU_TOOLS_SETUP, "\&Setup",
"Configure Music Organiser.");
# Create Help menu
$help_menu->Append($ID_MENU_HELP_CONTENTS, "\&Contents");
$help_menu->AppendSeparator();
$help_menu->Append($ID_MENU_HELP_ABOUT, "\&About");
# Create the menu bar that stores all the above menus
my $menubar = Wx::MenuBar->new();
$menubar->Append($file_menu, '&File');
$menubar->Append($edit_menu, '&Edit');
$menubar->Append($tools_menu, '&Tools');
$menubar->Append($help_menu, '&Help');
$self->SetMenuBar($menubar);
# Set up event handling for menu items.
EVT_MENU($self, $ID_MENU_FILE_REPORT, \&OnMenu);
# Set window icon
$self->SetIcon(Wx::GetWxPerlIcon());
# Create status bar and assign values to the various segments
$self->CreateStatusBar(3);
$self->SetStatusText("Welcome to Music Organiser!", 1);
$self->SetStatusText(scalar(gmtime), 2);
my ($splitter) = $self->{SPLITTER} =
MusicOrganiserSplitterWindow->new($self, -1);
my ($lcanvas) = $self->{LEFTCANVAS} = MyCanvas->new($splitter, -1,
[0,0], [400,40
+0],
'Test1');
my ($rcanvas) = $self->{RIGHTCANVAS} = MyCanvas->new($splitter, -1,
[0,0], [400,4
+00],
'Test2');
$self->{TREE} = MusicOrganiserTree->new($lcanvas, -1, wxDefaultPosit
+ion,
wxDefaultSize, wxTR_HAS_BUTTONS);
$self->{SPLITTER}->SetMinimumPaneSize(250);
$splitter->Initialize($lcanvas);
$self->{LEFTCANVAS}->Show( 1 );
$self->{RIGHTCANVAS}->Show( 1 );
$self->{SPLITTER}->SplitVertically( @{$self}{'LEFTCANVAS','RIGHTCANV
+AS'} );
$self->{SPLITTER}->SetSashPosition(250,1);
return $self;
}
sub OnMenu {
Wx::MessageBox("Menu item selected", "Menu selected",
wxOK | wxICON_INFORMATION, $_[0]);
}
package MusicOrganiserTree;
use strict;
use base qw(Wx::TreeCtrl);
sub new {
my $class = shift;
my $this = $class->SUPER::new(@_);
my $root = $this->AddRoot('Root', -1, -1, Wx::TreeItemData->new('Dat
+a'));
my $tree_item;
$tree_item = $this->AppendItem($root, "Please work", -1, -1,
Wx::TreeItemData->new("I really hope this works!"));
}
package MusicOrganiserApp;
use base qw(Wx::App);
sub OnInit {
my $self = shift;
my $frame = MusicOrganiserFrame->new(
undef, # Parent window
-1, # Window ID
'Music Organiser', # Window title
[1, 1], # X, Y position
[600, 300] # X, Y size
);
$self->SetTopWindow($frame); # Set the top-level window.
$frame->Show(1); # Show the frame.
}
package main;
my $app = MusicOrganiserApp->new();
$app->MainLoop;
