Suppress the '- default -' selection of Print/Filament/Printer settings

if there is any valid option available. This feature has been asked for
by the Prusa3D customers as the '- default -' option has nothing to do
with the actual printer and when selected accidentally, it could even
lead to a printer damage.

7 files changed, 136 insertions, 38 deletions

diff --git a/lib/Slic3r/Config.pm b/lib/Slic3r/Config.pm
index b4cfaa5d9..c315f9b4e 100644
--- a/lib/Slic3r/Config.pm
+++ b/lib/Slic3r/Config.pm
@@ -36,6 +36,7 @@ sub new_from_defaults {
     my (@opt_keys) = @_;
     
     my $self = $class->new;
+    # Instantiating the C++ class Slic3r::FullPrintConfig.
     my $defaults = Slic3r::Config::Full->new;
     if (@opt_keys) {
         $self->set($_, $defaults->get($_))
diff --git a/lib/Slic3r/GUI.pm b/lib/Slic3r/GUI.pm
index b91930870..614f74f61 100644
--- a/lib/Slic3r/GUI.pm
+++ b/lib/Slic3r/GUI.pm
@@ -69,10 +69,12 @@ our $Settings = {
         # If set, the "Controller" tab for the control of the printer over serial line and the serial port settings are hidden.
         # By default, Prusa has the controller hidden.
         no_controller => 1,
+        # If set, the "- default -" selections of print/filament/printer are suppressed, if there is a valid preset available.
+        no_defaults => 1,
     },
 };
 
-our $have_button_icons = &Wx::wxVERSION_STRING =~ / (?:2\.9\.[1-9]|3\.)/;
+our $have_button_icons = &Wx::wxVERSION_STRING =~ m" (?:2\.9\.[1-9]|3\.)";
 our $small_font = Wx::SystemSettings::GetFont(wxSYS_DEFAULT_GUI_FONT);
 $small_font->SetPointSize(11) if !&Wx::wxMSW;
 our $small_bold_font = Wx::SystemSettings::GetFont(wxSYS_DEFAULT_GUI_FONT);
@@ -126,6 +128,8 @@ sub OnInit {
         $Settings->{_}{background_processing} //= 1;
         # If set, the "Controller" tab for the control of the printer over serial line and the serial port settings are hidden.
         $Settings->{_}{no_controller} //= 1;
+        # If set, the "- default -" selections of print/filament/printer are suppressed, if there is a valid preset available.
+        $Settings->{_}{no_defaults} //= 1;
     }
     $Settings->{_}{version} = $Slic3r::VERSION;
     $self->save_settings;
diff --git a/lib/Slic3r/GUI/Controller.pm b/lib/Slic3r/GUI/Controller.pm
index c6a568f82..8c4dcbec7 100644
--- a/lib/Slic3r/GUI/Controller.pm
+++ b/lib/Slic3r/GUI/Controller.pm
@@ -177,9 +177,14 @@ sub print_panels {
         map $_->GetWindow, $self->{sizer}->GetChildren;
 }
 
+# Called by 
+#       Slic3r::GUI::Tab::Print::_on_presets_changed
+#       Slic3r::GUI::Tab::Filament::_on_presets_changed
+#       Slic3r::GUI::Tab::Printer::_on_presets_changed
+# when the presets are loaded or the user select another preset.
 sub update_presets {
     my $self = shift;
-    my ($group, $presets, $selected, $is_dirty) = @_;
+    my ($group, $presets, $default_suppressed, $selected, $is_dirty) = @_;
     
     # update configs of currently loaded print panels
     foreach my $panel ($self->print_panels) {
diff --git a/lib/Slic3r/GUI/MainFrame.pm b/lib/Slic3r/GUI/MainFrame.pm
index 3b7d7ef46..1969d8bea 100644
--- a/lib/Slic3r/GUI/MainFrame.pm
+++ b/lib/Slic3r/GUI/MainFrame.pm
@@ -140,6 +140,8 @@ sub _init_tabpanel {
                 $self->config->save($Slic3r::GUI::autosave) if $Slic3r::GUI::autosave;
             }
         });
+        # Install a callback for the tab to update the platter and print controller presets, when
+        # a preset changes at Slic3r::GUI::Tab.
         $tab->on_presets_changed(sub {
             if ($self->{plater}) {
                 $self->{plater}->update_presets($tab_name, @_);
@@ -393,7 +395,7 @@ sub quick_slice {
             print_center    => $print_center,
             status_cb       => sub {
                 my ($percent, $message) = @_;
-                return if &Wx::wxVERSION_STRING !~ / 2\.(8\.|9\.[2-9])/;
+                return if &Wx::wxVERSION_STRING !~ m" 2\.(8\.|9\.[2-9])";
                 $progress_dialog->Update($percent, "$message…");
             },
         );
diff --git a/lib/Slic3r/GUI/Plater.pm b/lib/Slic3r/GUI/Plater.pm
index dcc26c5e7..79cc8f994 100644
--- a/lib/Slic3r/GUI/Plater.pm
+++ b/lib/Slic3r/GUI/Plater.pm
@@ -330,12 +330,19 @@ sub new {
                 filament    => 'Filament',
                 printer     => 'Printer',
             );
+            # UI Combo boxes for a print, multiple filaments, and a printer.
+            # Initially a single filament combo box is created, but the number of combo boxes for the filament selection may increase,
+            # once a printer preset with multiple extruders is activated.
+            # $self->{preset_choosers}{$group}[$idx]
             $self->{preset_choosers} = {};
+            # Boolean indicating whether the '- default -' preset is shown by the combo box.
+            $self->{preset_choosers_default_suppressed} = {};
             for my $group (qw(print filament printer)) {
                 my $text = Wx::StaticText->new($self, -1, "$group_labels{$group}:", wxDefaultPosition, wxDefaultSize, wxALIGN_RIGHT);
                 $text->SetFont($Slic3r::GUI::small_font);
                 my $choice = Wx::BitmapComboBox->new($self, -1, "", wxDefaultPosition, wxDefaultSize, [], wxCB_READONLY);
                 $self->{preset_choosers}{$group} = [$choice];
+                $self->{preset_choosers_default_suppressed}{$group} = 0;
                 # setup the listener
                 EVT_COMBOBOX($choice, $choice, sub {
                     my ($choice) = @_;
@@ -427,18 +434,22 @@ sub _on_select_preset {
 	my $self = shift;
 	my ($group, $choice) = @_;
 	
-	# if user changed filament preset, don't propagate this to the tabs
+	# If user changed a filament preset and the selected machine is equipped with multiple extruders,
+    # there are multiple filament selection combo boxes shown at the platter. In that case
+    # don't propagate the filament selection changes to the tab.
+    my $default_suppressed = $self->{preset_choosers_default_suppressed}{$group};
 	if ($group eq 'filament' && @{$self->{preset_choosers}{filament}} > 1) {
+        # Indices of the filaments selected.
 		my @filament_presets = $self->filament_presets;
-		$Slic3r::GUI::Settings->{presets}{filament} = $choice->GetString($filament_presets[0]) . ".ini";
-		$Slic3r::GUI::Settings->{presets}{"filament_${_}"} = $choice->GetString($filament_presets[$_])
+		$Slic3r::GUI::Settings->{presets}{filament} = $choice->GetString($filament_presets[0] - $default_suppressed) . ".ini";
+		$Slic3r::GUI::Settings->{presets}{"filament_${_}"} = $choice->GetString($filament_presets[$_] - $default_suppressed)
 			for 1 .. $#filament_presets;
 		wxTheApp->save_settings;
 		return;
 	}
 	
 	# call GetSelection() in scalar context as it's context-aware
-	$self->{on_select_preset}->($group, scalar $choice->GetSelection)
+	$self->{on_select_preset}->($group, scalar($choice->GetSelection) + $default_suppressed)
 	    if $self->{on_select_preset};
 	
 	# get new config and generate on_config_change() event for updating plater and other things
@@ -450,20 +461,32 @@ sub GetFrame {
     return &Wx::GetTopLevelParent($self);
 }
 
+# Update presets (Print settings, Filament, Printer) from their respective tabs.
+# Called by 
+#       Slic3r::GUI::Tab::Print::_on_presets_changed
+#       Slic3r::GUI::Tab::Filament::_on_presets_changed
+#       Slic3r::GUI::Tab::Printer::_on_presets_changed
+# when the presets are loaded or the user selects another preset.
+# For Print settings and Printer, synchronize the selection index with their tabs.
+# For Filament, synchronize the selection index for a single extruder printer only, otherwise keep the selection.
 sub update_presets {
     my $self = shift;
-    my ($group, $presets, $selected, $is_dirty) = @_;
+    # $presets: one of qw(print filament printer)
+    # $selected: index of the selected preset in the array. This may not correspond
+    # with the index of selection in the UI element, where not all items are displayed.
+    my ($group, $presets, $default_suppressed, $selected, $is_dirty) = @_;
     
     my @choosers = @{ $self->{preset_choosers}{$group} };
     foreach my $choice (@choosers) {
         if ($group eq 'filament' && @choosers > 1) {
             # if we have more than one filament chooser, keep our selection
             # instead of importing the one from the tab
-            $selected = $choice->GetSelection;
+            $selected = $choice->GetSelection + $self->{preset_choosers_default_suppressed}{$group};
             $is_dirty = 0;
         }
         $choice->Clear;
         foreach my $preset (@$presets) {
+            next if ($preset->default && $default_suppressed);
             my $bitmap;
             if ($group eq 'filament') {
                 my $config = $preset->config(['filament_colour']);
@@ -486,21 +509,26 @@ sub update_presets {
         }
         
         if ($selected <= $#$presets) {
-            if ($is_dirty) {
-                $choice->SetString($selected, $choice->GetString($selected) . " (modified)");
+            my $idx = $selected - $default_suppressed;
+            if ($idx >= 0) {
+                if ($is_dirty) {
+                    $choice->SetString($idx, $choice->GetString($idx) . " (modified)");
+                }
+                # call SetSelection() only after SetString() otherwise the new string
+                # won't be picked up as the visible string
+                $choice->SetSelection($idx);
             }
-            # call SetSelection() only after SetString() otherwise the new string
-            # won't be picked up as the visible string
-            $choice->SetSelection($selected);
         }
     }
+
+    $self->{preset_choosers_default_suppressed}{$group} = $default_suppressed;
 }
 
+# Return a vector of indices of filaments selected by the $self->{preset_choosers}{filament} combo boxes.
 sub filament_presets {
     my $self = shift;
-    
     # force scalar context for GetSelection() as it's context-aware
-    return map scalar($_->GetSelection), @{ $self->{preset_choosers}{filament} };
+    return map scalar($_->GetSelection) + $self->{preset_choosers_default_suppressed}{filament}, @{ $self->{preset_choosers}{filament} };
 }
 
 sub add {
@@ -1436,6 +1464,7 @@ sub update {
     $self->refresh_canvases;
 }
 
+# When a number of extruders changes, the UI needs to be updated to show a single filament selection combo box per extruder.
 sub on_extruders_change {
     my ($self, $num_extruders) = @_;
     
diff --git a/lib/Slic3r/GUI/Preferences.pm b/lib/Slic3r/GUI/Preferences.pm
index 431f642d6..9c36d3098 100644
--- a/lib/Slic3r/GUI/Preferences.pm
+++ b/lib/Slic3r/GUI/Preferences.pm
@@ -67,6 +67,13 @@ sub new {
         tooltip     => 'Disable communication with the printer over a serial / USB cable. This simplifies the user interface in case the printer is never attached to the computer.',
         default     => $Slic3r::GUI::Settings->{_}{no_controller},
     ));
+    $optgroup->append_single_option_line(Slic3r::GUI::OptionsGroup::Option->new(
+        opt_id      => 'no_defaults',
+        type        => 'bool',
+        label       => 'Suppress "- default -" presets',
+        tooltip     => 'Suppress "- default -" presets in the Print / Filament / Printer selections once there are any other valid presets available.',
+        default     => $Slic3r::GUI::Settings->{_}{no_defaults},
+    ));
     
     my $sizer = Wx::BoxSizer->new(wxVERTICAL);
     $sizer->Add($optgroup->sizer, 0, wxEXPAND | wxBOTTOM | wxLEFT | wxRIGHT, 10);
diff --git a/lib/Slic3r/GUI/Tab.pm b/lib/Slic3r/GUI/Tab.pm
index c05465664..d30e31abc 100644
--- a/lib/Slic3r/GUI/Tab.pm
+++ b/lib/Slic3r/GUI/Tab.pm
@@ -1,6 +1,18 @@
 # The "Expert" tab at the right of the main tabbed window.
 # The "Expert" is enabled by File->Preferences dialog.
 
+# This file implements following packages:
+#   Slic3r::GUI::Tab;
+#       Slic3r::GUI::Tab::Print;
+#       Slic3r::GUI::Tab::Filament;
+#       Slic3r::GUI::Tab::Printer;
+#   Slic3r::GUI::Tab::Page
+#       - Option page: For example, the Slic3r::GUI::Tab::Print has option pages "Layers and perimeters", "Infill", "Skirt and brim" ...
+#   Slic3r::GUI::SavePresetWindow
+#       - Dialog to select a new preset name to store the configuration.
+#   Slic3r::GUI::Tab::Preset;
+#       - Single preset item: name, file is default or external.
+
 package Slic3r::GUI::Tab;
 use strict;
 use warnings;
@@ -13,6 +25,7 @@ use Wx qw(:bookctrl :dialog :keycode :icon :id :misc :panel :sizer :treectrl :wi
 use Wx::Event qw(EVT_BUTTON EVT_CHOICE EVT_KEY_DOWN EVT_TREE_SEL_CHANGED);
 use base qw(Wx::Panel Class::Accessor);
 
+# Index of the currently active preset.
 __PACKAGE__->mk_accessors(qw(current_preset));
 
 sub new {
@@ -30,7 +43,7 @@ sub new {
     $self->{sizer}->Add($left_sizer, 0, wxEXPAND | wxLEFT | wxTOP | wxBOTTOM, 3);
     
     my $left_col_width = 150;
-    
+
     # preset chooser
     {
         
@@ -96,16 +109,32 @@ sub new {
     
     EVT_BUTTON($self, $self->{btn_delete_preset}, sub {
         my $i = $self->current_preset;
-        return if $i == 0;  # this shouldn't happen but let's trap it anyway
+        # Don't let the user delete the '- default -' configuration.
+        # This shall not happen as the 'delete' button is disabled for the '- default -' entry,
+        # but better be safe than sorry.
+        return if ($i == 0 && $self->get_current_preset->{default});
         my $res = Wx::MessageDialog->new($self, "Are you sure you want to delete the selected preset?", 'Delete Preset', wxYES_NO | wxNO_DEFAULT | wxICON_QUESTION)->ShowModal;
         return unless $res == wxID_YES;
-        if (-e $self->{presets}[$i]->file) {
-            unlink $self->{presets}[$i]->file;
+        # Delete the file.
+        my $path = Slic3r::encode_path($self->{presets}[$i]->file);
+        if (-e $path && ! unlink $path) {
+            # Cannot delete the file, therefore the item will not be removed from the selection.
+            Slic3r::GUI::show_error($self, "Cannot delete file $path : $!");
+            return;
         }
+        # Delete the preset.
         splice @{$self->{presets}}, $i, 1;
-        $self->{presets_choice}->Delete($i);
+        # Delete the item from the UI component.
+        $self->{presets_choice}->Delete($i - $self->{default_suppressed});
         $self->current_preset(undef);
-        $self->select_preset(0);
+        if ($self->{default_suppressed} && scalar(@{$self->{presets}}) == 1) {
+            # Empty selection. Add the '- default -' item into the drop down selection.
+            $self->{presets_choice}->Append($self->{presets}->[0]->name);
+            # and remember that the '- default -' is shown.
+            $self->{default_suppressed} = 0;
+        }
+        # Select the 0th item. If default is suppressed, select the first valid.
+        $self->select_preset($self->{default_suppressed});
         $self->_on_presets_changed;
     });
     
@@ -120,11 +149,18 @@ sub new {
     return $self;
 }
 
+# Are the '- default -' selections suppressed by the Slic3r GUI preferences?
+sub no_defaults {
+    return $Slic3r::GUI::Settings->{_}{no_defaults} ? 1 : 0;
+}
+
+# Get a currently active preset (Perl class Slic3r::GUI::Tab::Preset).
 sub get_current_preset {
     my $self = shift;
     return $self->get_preset($self->current_preset);
 }
 
+# Get a preset (Perl class Slic3r::GUI::Tab::Preset) with an index $i.
 sub get_preset {
     my ($self, $i) = @_;
     return $self->{presets}[$i];
@@ -185,7 +221,8 @@ sub _on_presets_changed {
     
     $self->{on_presets_changed}->(
         $self->{presets},
-        scalar($self->{presets_choice}->GetSelection),
+        $self->{default_suppressed},
+        scalar($self->{presets_choice}->GetSelection) + $self->{default_suppressed},
         $self->is_dirty,
     ) if $self->{on_presets_changed};
 }
@@ -200,8 +237,18 @@ sub select_default_preset {
 }
 
 sub select_preset {
-    my $self = shift;
-    $self->{presets_choice}->SetSelection($_[0]);
+    my ($self, $i) = @_;
+    if ($self->{default_suppressed} && $i == 0) {
+        # Selecting the '- default -'. Add it to the combo box.
+        $self->{default_suppressed} = 0;
+        $self->{presets_choice}->Insert($self->{presets}->[0]->name, 0);
+    } elsif ($self->no_defaults && ! $self->{default_suppressed} && $i > 0) {
+        # The user wants to hide the '- default -' items and a non-default item has been added to the presets.
+        # Hide the '- default -' item.
+        $self->{presets_choice}->Delete(0);
+        $self->{default_suppressed} = 1;
+    }
+    $self->{presets_choice}->SetSelection($i - $self->{default_suppressed});
     $self->on_select_preset;
 }
 
@@ -216,6 +263,7 @@ sub on_select_preset {
     my $self = shift;
     
     if ($self->is_dirty) {
+        # Display a dialog showing the dirty options in a human readable form.
         my $old_preset = $self->get_current_preset;
         my $name = $old_preset->default ? 'Default preset' : "Preset \"" . $old_preset->name . "\"";
         
@@ -233,7 +281,7 @@ sub on_select_preset {
         my $confirm = Wx::MessageDialog->new($self, "$name has unsaved changes:\n$changes\n\nDiscard changes and continue anyway?",
                                              'Unsaved Changes', wxYES_NO | wxNO_DEFAULT | wxICON_QUESTION);
         if ($confirm->ShowModal == wxID_NO) {
-            $self->{presets_choice}->SetSelection($self->current_preset);
+            $self->{presets_choice}->SetSelection($self->current_preset - $self->{default_suppressed});
             
             # trigger the on_presets_changed event so that we also restore the previous value
             # in the plater selector
@@ -242,7 +290,7 @@ sub on_select_preset {
         }
     }
     
-    $self->current_preset($self->{presets_choice}->GetSelection);
+    $self->current_preset($self->{presets_choice}->GetSelection + $self->{default_suppressed});
     my $preset = $self->get_current_preset;
     my $preset_config = $self->get_preset_config($preset);
     eval {
@@ -333,15 +381,13 @@ sub update_tree {
 sub update_dirty {
     my $self = shift;
     
-    foreach my $i (0..$#{$self->{presets}}) {
+    foreach my $i ($self->{default_suppressed}..$#{$self->{presets}}) {
         my $preset = $self->get_preset($i);
-        if ($i == $self->current_preset && $self->is_dirty) {
-            $self->{presets_choice}->SetString($i, $preset->name . " (modified)");
-        } else {
-            $self->{presets_choice}->SetString($i, $preset->name);
-        }
+        $self->{presets_choice}->SetString(
+            $i - $self->{default_suppressed}, 
+            ($i == $self->current_preset && $self->is_dirty) ? $preset->name . " (modified)" : $preset->name);
     }
-    $self->{presets_choice}->SetSelection($self->current_preset);  # http://trac.wxwidgets.org/ticket/13769
+    $self->{presets_choice}->SetSelection($self->current_preset - $self->{default_suppressed});  # http://trac.wxwidgets.org/ticket/13769
     $self->_on_presets_changed;
 }
 
@@ -374,14 +420,17 @@ sub load_presets {
             file => $presets{$preset_name},
         );
     }
-    
     $self->current_preset(undef);
+    $self->{default_suppressed} = Slic3r::GUI::Tab->no_defaults && scalar(@{$self->{presets}}) > 1;
     $self->{presets_choice}->Clear;
-    $self->{presets_choice}->Append($_->name) for @{$self->{presets}};
+    foreach my $preset (@{$self->{presets}}) {
+        next if ($preset->default && $self->{default_suppressed});
+        $self->{presets_choice}->Append($preset->name);
+    }
     {
         # load last used preset
         my $i = first { basename($self->{presets}[$_]->file) eq ($Slic3r::GUI::Settings->{presets}{$self->name} || '') } 1 .. $#{$self->{presets}};
-        $self->select_preset($i || 0);
+        $self->select_preset($i || $self->{default_suppressed});
     }
     $self->_on_presets_changed;
 }
@@ -402,7 +451,7 @@ sub load_config_file {
         $self->{presets_choice}->Append($preset_name);
         $i = $#{$self->{presets}};
     }
-    $self->{presets_choice}->SetSelection($i);
+    $self->{presets_choice}->SetSelection($i - $self->{default_suppressed});
     $self->on_select_preset;
     $self->_on_presets_changed;
 }
@@ -1584,6 +1633,7 @@ sub config {
     my ($self, $keys) = @_;
     
     if ($self->default) {
+        # Perl class Slic3r::Config extends the C++ class Slic3r::DynamicPrintConfig
         return Slic3r::Config->new_from_defaults(@$keys);
     } else {
         if (!-e Slic3r::encode_path($self->file)) {