--- deliantra/Deliantra-Client/DC/UI.pm	2007/07/16 12:36:48	1.374
+++ deliantra/Deliantra-Client/DC/UI.pm	2007/07/16 20:12:19	1.375
@@ -946,6 +946,8 @@
 
 package CFPlus::UI::ViewPort;
 
+use List::Util qw(min max);
+
 our @ISA = CFPlus::UI::Window::;
 
 sub new {
@@ -986,8 +988,8 @@
 sub set_offset {
    my ($self, $x, $y) = @_;
 
-   $self->{view_x} = int $x;
-   $self->{view_y} = int $y;
+   $self->{view_x} = max 0, min $self->child->{w} - $self->{w}, int $x;
+   $self->{view_y} = max 0, min $self->child->{h} - $self->{h}, int $y;
 
    $self->update;
 }
@@ -1094,16 +1096,6 @@
    $self->{vp}->add ($self->{child} = $widget);
 }
 
-sub invoke_mouse_wheel {
-   my ($self, $ev) = @_;
-
-   return 0 unless $ev->{dy}; # only vertical movements for now
-
-   $self->{vslider}->emit (mouse_wheel => $ev);
-
-   1
-}
-
 sub update_slider {
    my ($self) = @_;
 
@@ -1135,6 +1127,58 @@
    $self->update_slider;
 }
 
+sub invoke_mouse_wheel {
+   my ($self, $ev) = @_;
+
+   return 0 unless $ev->{dy}; # only vertical movements for now
+
+   $self->{vslider}->emit (mouse_wheel => $ev);
+
+   1
+}
+
+sub invoke_button_down {
+   my ($self, $ev, $x, $y) = @_;
+
+   if ($ev->{button} == 2) {
+      $self->grab_focus;
+      
+      $self->{motion} = sub {
+         my ($ev, $x, $y) = @_;
+
+         $self->{vp}->set_offset (
+            $self->{vp}{view_x} - $ev->{xrel},
+            $self->{vp}{view_y} - $ev->{yrel},
+         );
+      };
+
+      return 1;
+   }
+
+   0
+}
+
+sub invoke_button_up {
+   my ($self, $ev, $x, $y) = @_;
+
+   if (delete $self->{motion}) {
+      return 1;
+   }
+
+   0
+}
+
+sub invoke_mouse_motion {
+   my ($self, $ev, $x, $y) = @_;
+
+   if ($self->{motion}) {
+      $self->{motion}->($ev, $x, $y);
+      return 1;
+   }
+
+   0
+}
+
 sub invoke_size_allocate {
    my ($self, $w, $h) = @_;