Add a lightweight (text only) Gtk.HTML based web browser example

sorear · Oct 3, 2011 · 5239f11 · 5239f11
1 parent b08643d
commit 5239f11
Showing 1 changed file with 83 additions and 0 deletions.
diff --git a/examples/gtk-webbrowser.pl b/examples/gtk-webbrowser.pl
@@ -0,0 +1,83 @@
+# gtk-webbrowser.pl - based on the Gtk C# example
+# see Gnome Libraries, Gtk, HTML class at http://docs.go-mono.com/
+# needs libgtkhtml3.16-cil on Debian or Ubuntu
+
+# Names that occur multiple times.  Names used only once appear inline.
+constant $GTK     = "gtk-sharp,     Version=2.12.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f";
+constant $GTKHTML = "gtkhtml-sharp, Version=3.16.0.0, Culture=neutral, PublicKeyToken=35e10195dab3c99f";
+constant $SYSTEM  = "System,        Version=2.0.0.0,  Culture=neutral, PublicKeyToken=b77a5c561934e089";
+constant Application  = CLR::("Gtk.Application,$GTK");
+
+# ---------------------------- Main program ----------------------------
+Application.Init;
+my $currentUrl; my @historyUrl; my $name = "Niecza web browser";
+my $label = CLR::("Gtk.Label,$GTK").new("Address:");
+my $entry = CLR::("Gtk.Entry,$GTK").new;
+$entry.add_Activated(&EntryActivated);
+my $buttonGo = CLR::("Gtk.Button,$GTK").new("Go!");
+$buttonGo.add_Clicked(&EntryActivated);  # share $entry's handler
+my $buttonBack = CLR::("Gtk.Button,$GTK").new("Back");
+$buttonBack.add_Clicked(&BackClicked);
+my $hbox = CLR::("Gtk.HBox,$GTK").new(False, 1);
+$hbox.PackStart($label, False, False, 1);
+$hbox.PackStart($entry, True, True, 1);
+$hbox.PackStart($buttonGo, False, False, 1);
+$hbox.PackStart($buttonBack, False, False, 1);
+my $html = CLR::("Gtk.HTML,$GTKHTML").new;
+$html.add_LinkClicked(&LinkClicked);
+my $sw = CLR::("Gtk.ScrolledWindow,$GTK").new;
+$sw.VscrollbarPolicy = CLR::("Gtk.PolicyType,$GTK").Always;
+$sw.HscrollbarPolicy = CLR::("Gtk.PolicyType,$GTK").Always;
+$sw.Add($html);
+my $vbox = CLR::("Gtk.VBox,$GTK").new(False, 1);
+$vbox.PackStart($hbox, False, False, 1);
+$vbox.PackStart($sw, True, True, 1);
+my $win = CLR::("Gtk.Window,$GTK").new($name);
+$win.SetDefaultSize(800, 600);
+$win.add_DeleteEvent(sub ($o,$a) { Application.Quit(); });  #OK not used
+$win.Add($vbox);
+$win.ShowAll;
+Application.Run;
+
+# --------------------------- Event handlers ---------------------------
+sub EntryActivated($obj, $args)  #OK not used
+{
+    if $currentUrl { push @historyUrl, $currentUrl; }
+    $currentUrl = $entry.Text.subst(/^\s+/,"").subst(/\s+$/,"");  # trim
+    LoadHtml($currentUrl);
+}
+
+sub LinkClicked($obj, $args)  #OK not used
+{
+    my $newUrl =  $args.Url ~~ /^ 'http://' /  # decide absolute or relative '
+        ?? $args.Url
+        !! $currentUrl ~ $args.Url;
+    try {
+        LoadHtml($newUrl);      # apparently throws numerous exceptions
+        CATCH { }               # hide the evidence of the failure
+        push @historyUrl, $currentUrl;
+        $currentUrl = $newUrl;
+    }
+}
+
+sub BackClicked($obj, $args) #OK not used
+{
+    if @historyUrl { LoadHtml($currentUrl = pop @historyUrl); }
+}
+
+# ------------------------- Helper subroutines -------------------------
+sub LoadHtml($Url is copy)
+{
+    unless $Url ~~ /^ [http|https] '://' / { $Url = 'http://' ~ $Url } # '
+    my $web_request = CLR::("System.Net.WebRequest,$SYSTEM").Create($Url);
+    my $web_response = $web_request.GetResponse;
+    my $stream = $web_response.GetResponseStream;
+    my $buffer = CLR::("System.Byte[]").new(8192);
+    my $html_stream = $html.Begin;
+    while (my $count = $stream.Read($buffer, 0, 8192)) != 0 {
+        $html_stream.Write($buffer, $count);
+    }
+    $html.End($html_stream, CLR::("Gtk.HTMLStreamStatus,$GTKHTML").Ok);
+    $entry.Text = $Url;
+    $win.Title = $html.Title ~ " - $name";
+}