Linux – Tunning scrolling in urxvt

I haven't tested this specifically for emacs yet, but this allows for mouse scrolling when using vim,less,man,etc. Paste this in $HOME/.urxvt/ext/vtwheel (create the file if it doesn't exist):

#! perl

# Implements a scrollwheel just like in good old vt100's mices

sub simulate_keypress {
    my ($self, $type) = @_; #type: 0:up, 1:down

    my $keycode_up = 111;
    my $keycode_down = 116;

    my $numlines = 3;

    my $keycode = 0;
    if ($type eq 0) {
        $keycode = $keycode_up;
    } elsif ($type eq 1) {
        $keycode = $keycode_down;
    } else {
        return;
    }

    for (my $i = 0 ; $i ne $numlines ; $i++) {
        $self->key_press(0,$keycode);
        $self->key_release(0,$keycode);
    }
}

sub on_button_release {
    my ($self, $event) = @_;

    #my $res_ss = $self->resource("secondaryScroll");
    #warn("ressource ss is <$res_ss>");

    !$self->current_screen and return ();

    #warn("foo, event: <$event->{button}>\n");
    if ($event->{button} eq "4") { # scroll up
        $self->simulate_keypress(0);
        return 1;
    } elsif ($event->{button} eq "5") { # scroll down
        $self->simulate_keypress(1);
        return 1;
    }

    return ();
}

Then add URxvt.perl-ext-common:vtewheel to your .Xresources (or .Xdefaults) and run xrdb .Xresources

Source: https://aur.archlinux.org/cgit/aur.git/tree/vtwheel?h=urxvt-vtwheel

In the upper menu go to Settings/Configuration, and then under the Toolbar menu add buttons for Zoom in and Zoom out to be displayed.