kicad/pcbnew/router/router_tool.cpp

/*
 * KiRouter - a push-and-(sometimes-)shove PCB router
 *
 * Copyright (C) 2013-2017 CERN
 * Copyright (C) 2017 KiCad Developers, see AUTHORS.txt for contributors.
 * Author: Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <wx/numdlg.h>

#include <core/optional.h>
#include <functional>
using namespace std::placeholders;

#include "class_draw_panel_gal.h"
#include "class_board.h"

#include <pcb_edit_frame.h>
#include <id.h>
#include <macros.h>
#include <pcbnew_id.h>
#include <view/view.h>
#include <view/view_controls.h>
#include <pcb_painter.h>
#include <dialogs/dialog_pns_settings.h>
#include <dialogs/dialog_pns_diff_pair_dimensions.h>
#include <dialogs/dialog_track_via_size.h>
#include <base_units.h>
#include <hotkeys.h>
#include <confirm.h>
#include <bitmaps.h>
#include <collectors.h>

#include <tool/context_menu.h>
#include <tool/tool_manager.h>
#include <tool/tool_settings.h>
#include <tool/grid_menu.h>

#include <tool/zoom_menu.h>
#include <tools/pcb_actions.h>
#include <tools/size_menu.h>
#include <tools/selection_tool.h>
#include <tools/edit_tool.h>
#include <tools/tool_event_utils.h>

#include "router_tool.h"
#include "pns_segment.h"
#include "pns_router.h"

using namespace KIGFX;

/**
 * Flags used by via tool actions
 */
enum VIA_ACTION_FLAGS
{
    // Via type
    VIA_MASK     = 0x03,
    VIA          = 0x00,     ///> Normal via
    BLIND_VIA    = 0x01,     ///> blind/buried via
    MICROVIA     = 0x02,     ///> Microvia

    // Select layer
    SELECT_LAYER = VIA_MASK + 1,    ///> Ask user to select layer before adding via
};


TOOL_ACTION PCB_ACTIONS::routerActivateSingle( "pcbnew.InteractiveRouter.SingleTrack",
        AS_GLOBAL, TOOL_ACTION::LegacyHotKey( HK_ADD_NEW_TRACK ),
        _( "Interactive Router (Single Tracks)" ),
        _( "Run push & shove router (single tracks)" ), ps_router_xpm, AF_ACTIVATE );

TOOL_ACTION PCB_ACTIONS::routerActivateDiffPair( "pcbnew.InteractiveRouter.DiffPair",
        AS_GLOBAL, '6',
        _( "Interactive Router (Differential Pairs)" ),
        _( "Run push & shove router (differential pairs)" ), ps_diff_pair_xpm, AF_ACTIVATE );

TOOL_ACTION PCB_ACTIONS::routerActivateSettingsDialog( "pcbnew.InteractiveRouter.SettingsDialog",
        AS_GLOBAL, 0,
        _( "Interactive Router Settings..." ),
        _( "Open Interactive Router settings" ), NULL, AF_ACTIVATE );

TOOL_ACTION PCB_ACTIONS::routerActivateDpDimensionsDialog( "pcbnew.InteractiveRouter.DpDimensionsDialog",
        AS_GLOBAL, 0,
        _( "Differential Pair Dimension Settings..." ),
        _( "Open Differential Pair Dimension settings" ), ps_diff_pair_gap_xpm, AF_ACTIVATE );

TOOL_ACTION PCB_ACTIONS::routerActivateTuneSingleTrace( "pcbnew.LengthTuner.TuneSingleTrack",
        AS_GLOBAL, '7',
        _( "Tune length of a single track" ), "", ps_tune_length_xpm, AF_ACTIVATE );

TOOL_ACTION PCB_ACTIONS::routerActivateTuneDiffPair( "pcbnew.LengthTuner.TuneDiffPair",
        AS_GLOBAL, '8',
        _( "Tune length of a differential pair" ), "", NULL, AF_ACTIVATE );

TOOL_ACTION PCB_ACTIONS::routerActivateTuneDiffPairSkew( "pcbnew.LengthTuner.TuneDiffPairSkew",
        AS_GLOBAL, '9',
        _( "Tune skew of a differential pair" ), "", NULL, AF_ACTIVATE );

TOOL_ACTION PCB_ACTIONS::routerInlineDrag( "pcbnew.InteractiveRouter.InlineDrag",
        AS_CONTEXT, 0,
        _( "Drag Track/Via" ), _( "Drags tracks and vias without breaking connections" ),
        drag_xpm );

TOOL_ACTION PCB_ACTIONS::breakTrack( "pcbnew.InteractiveRouter.BreakTrack",
        AS_GLOBAL, 0,
        _( "Break Track" ),
        _( "Splits the track segment into two segments connected at the cursor position." ),
        break_line_xpm );

TOOL_ACTION PCB_ACTIONS::drag45Degree( "pcbnew.InteractiveRouter.Drag45Degree",
        AS_GLOBAL, TOOL_ACTION::LegacyHotKey( HK_DRAG_TRACK_KEEP_SLOPE ),
        _( "Drag (45 degree mode)" ),
        _( "todo" ),
        drag_segment_withslope_xpm );

TOOL_ACTION PCB_ACTIONS::dragFreeAngle( "pcbnew.InteractiveRouter.DragFreeAngle",
        AS_GLOBAL, TOOL_ACTION::LegacyHotKey( HK_DRAG_ITEM ),
        _( "Drag (free angle)" ),
        _( "todo" ),
        move_xpm );

static const TOOL_ACTION ACT_NewTrack( "pcbnew.InteractiveRouter.NewTrack", AS_CONTEXT,
    TOOL_ACTION::LegacyHotKey( HK_ADD_NEW_TRACK ),
    _( "New Track" ),  _( "Starts laying a new track." ), add_tracks_xpm );

static const TOOL_ACTION ACT_EndTrack( "pcbnew.InteractiveRouter.EndTrack", AS_CONTEXT, WXK_END,
    _( "End Track" ),  _( "Stops laying the current track." ), checked_ok_xpm );

static const TOOL_ACTION ACT_AutoEndRoute( "pcbnew.InteractiveRouter.AutoEndRoute", AS_CONTEXT, 'F',
    _( "Auto-end Track" ),  _( "Automagically finishes currently routed track." ) );

static const TOOL_ACTION ACT_PlaceThroughVia( "pcbnew.InteractiveRouter.PlaceVia",
    AS_CONTEXT, TOOL_ACTION::LegacyHotKey( HK_ADD_THROUGH_VIA ),
    _( "Place Through Via" ),
    _( "Adds a through-hole via at the end of currently routed track." ),
    via_xpm, AF_NONE,
    (void*) VIA_ACTION_FLAGS::VIA );

static const TOOL_ACTION ACT_PlaceBlindVia( "pcbnew.InteractiveRouter.PlaceBlindVia",
    AS_CONTEXT, TOOL_ACTION::LegacyHotKey( HK_ADD_BLIND_BURIED_VIA ),
    _( "Place Blind/Buried Via" ),
    _( "Adds a blind or buried via at the end of currently routed track."),
    via_buried_xpm, AF_NONE,
    (void*) VIA_ACTION_FLAGS::BLIND_VIA );

static const TOOL_ACTION ACT_PlaceMicroVia( "pcbnew.InteractiveRouter.PlaceMicroVia",
    AS_CONTEXT, TOOL_ACTION::LegacyHotKey( HK_ADD_MICROVIA ),
    _( "Place Microvia" ), _( "Adds a microvia at the end of currently routed track." ),
    via_microvia_xpm, AF_NONE,
    (void*) VIA_ACTION_FLAGS::MICROVIA );

static const TOOL_ACTION ACT_SelLayerAndPlaceThroughVia(
    "pcbnew.InteractiveRouter.SelLayerAndPlaceVia",
    AS_CONTEXT, TOOL_ACTION::LegacyHotKey( HK_SEL_LAYER_AND_ADD_THROUGH_VIA ),
    _( "Select Layer and Place Through Via..." ),
    _( "Select a layer, then add a through-hole via at the end of currently routed track." ),
    select_w_layer_xpm, AF_NONE,
    (void*) ( VIA_ACTION_FLAGS::VIA | VIA_ACTION_FLAGS::SELECT_LAYER ) );

static const TOOL_ACTION ACT_SelLayerAndPlaceBlindVia(
    "pcbnew.InteractiveRouter.SelLayerAndPlaceBlindVia",
    AS_CONTEXT, TOOL_ACTION::LegacyHotKey( HK_SEL_LAYER_AND_ADD_BLIND_BURIED_VIA ),
    _( "Select Layer and Place Blind/Buried Via..." ),
    _( "Select a layer, then add a blind or buried via at the end of currently routed track."),
    select_w_layer_xpm, AF_NONE,
    (void*) ( VIA_ACTION_FLAGS::BLIND_VIA | VIA_ACTION_FLAGS::SELECT_LAYER ) );

static const TOOL_ACTION ACT_CustomTrackWidth( "pcbnew.InteractiveRouter.CustomTrackViaSize",
    AS_CONTEXT, TOOL_ACTION::LegacyHotKey( HK_CUSTOM_TRACK_WIDTH ),
    _( "Custom Track/Via Size..." ),
    _( "Shows a dialog for changing the track width and via size." ),
    width_track_xpm );

static const TOOL_ACTION ACT_SwitchPosture( "pcbnew.InteractiveRouter.SwitchPosture", AS_CONTEXT,
    TOOL_ACTION::LegacyHotKey( HK_SWITCH_TRACK_POSTURE ),
    _( "Switch Track Posture" ),
    _( "Switches posture of the currently routed track." ),
    change_entry_orient_xpm );

static const TOOL_ACTION ACT_SetDpDimensions( "pcbnew.InteractiveRouter.SetDpDimensions",
    AS_CONTEXT, TOOL_ACTION::LegacyHotKey( HK_DP_DIMENSIONS ),
    _( "Differential Pair Dimensions..." ),
    _( "Sets the width and gap of the currently routed differential pair." ),
    ps_diff_pair_tune_length_xpm );

ROUTER_TOOL::ROUTER_TOOL() :
    TOOL_BASE( "pcbnew.InteractiveRouter" )
{
}


class TRACK_WIDTH_MENU: public TRACK_VIA_SIZE_MENU
{
public:
    TRACK_WIDTH_MENU( const BOARD* aBoard )
        : TRACK_VIA_SIZE_MENU( true, true )
    {
        SetTitle( _( "Select Track/Via Width" ) );
        SetBoard( aBoard );
    }

    void SetBoard( const BOARD* aBoard )
    {
        m_board = aBoard;

        Clear();

        Append( ID_POPUP_PCB_SELECT_CUSTOM_WIDTH, _( "Custom Size" ),
                wxEmptyString, wxITEM_CHECK );

        Append( ID_POPUP_PCB_SELECT_AUTO_WIDTH, _( "Use Starting Track Width" ),
                _( "Route using the width of the starting track." ), wxITEM_CHECK );

        Append( ID_POPUP_PCB_SELECT_USE_NETCLASS_VALUES, _( "Use Net Class Values" ),
                _( "Use track and via sizes from the net class" ), wxITEM_CHECK );

        AppendSeparator();

        // Append the list of tracks & via sizes
        AppendSizes( aBoard );
    }

protected:
    CONTEXT_MENU* create() const override
    {
        return new TRACK_WIDTH_MENU( m_board );
    }

    OPT_TOOL_EVENT eventHandler( const wxMenuEvent& aEvent ) override
    {
        BOARD_DESIGN_SETTINGS &bds = m_board->GetDesignSettings();
        int id = aEvent.GetId();

        // On Windows, this handler can be called with a  non existing event ID not existing
        // in any menuitem.
        // So we keep trace of in-range/out-of-range event ID
        bool in_range = true;

        // Initial settings, to be modified below, but only if the ID exists in this menu
        bool useConnectedTrackWidth = false;
        bool useCustomTrackViaSize = false;

        if( id == ID_POPUP_PCB_SELECT_CUSTOM_WIDTH )
        {
            useCustomTrackViaSize = true;
        }
        else if( id == ID_POPUP_PCB_SELECT_AUTO_WIDTH )
        {
            useConnectedTrackWidth = true;
        }
        else if( id == ID_POPUP_PCB_SELECT_USE_NETCLASS_VALUES )
        {
            bds.SetViaSizeIndex( 0 );
            bds.SetTrackWidthIndex( 0 );
        }
        else if( id >= ID_POPUP_PCB_SELECT_VIASIZE1 &&
                 id <= ID_POPUP_PCB_SELECT_VIASIZE16 )
        {
           // via size has changed
            bds.SetViaSizeIndex( id - ID_POPUP_PCB_SELECT_VIASIZE1 );
        }
        else if( id >= ID_POPUP_PCB_SELECT_WIDTH1 &&
                 id <= ID_POPUP_PCB_SELECT_WIDTH16 )
        {
            // track width has changed
            bds.SetTrackWidthIndex( id - ID_POPUP_PCB_SELECT_WIDTH1 );
        }
        else
        {
            in_range = false;   // This event ID does not exist in the menu
            wxASSERT_MSG( false, "OPT_TOOL_EVENT EventHandler: unexpected id" );
            // Fix me: How to return this error as OPT_TOOL_EVENT?
        }

        if( in_range )
        {
            // Update this setup only id the event ID matches the options of this menu
            bds.m_UseConnectedTrackWidth = useConnectedTrackWidth;
            bds.UseCustomTrackViaSize( useCustomTrackViaSize );
        }

        return OPT_TOOL_EVENT( PCB_ACTIONS::trackViaSizeChanged.MakeEvent() );
    }

private:
    const BOARD* m_board;
};


class ROUTER_TOOL_MENU : public CONTEXT_MENU
{
public:
    ROUTER_TOOL_MENU( const BOARD* aBoard, PCB_EDIT_FRAME& aFrame, PNS::ROUTER_MODE aMode ) :
        m_board( aBoard ), m_frame( aFrame ), m_mode( aMode ),
        m_widthMenu( aBoard ), m_zoomMenu( &aFrame ), m_gridMenu( &aFrame )
    {
        SetTitle( _( "Interactive Router" ) );

        Add( ACTIONS::cancelInteractive );

        AppendSeparator();

        Add( ACT_NewTrack );
        Add( ACT_EndTrack );
        Add( PCB_ACTIONS::breakTrack );

        Add( PCB_ACTIONS::drag45Degree );
        Add( PCB_ACTIONS::dragFreeAngle );

//        Add( ACT_AutoEndRoute );  // fixme: not implemented yet. Sorry.
        Add( ACT_PlaceThroughVia );
        Add( ACT_PlaceBlindVia );
        Add( ACT_PlaceMicroVia );
        Add( ACT_SelLayerAndPlaceThroughVia );
        Add( ACT_SelLayerAndPlaceBlindVia );
        Add( ACT_SwitchPosture );

        AppendSeparator();

        m_widthMenu.SetBoard( aBoard );
        Add( &m_widthMenu );

        Add( ACT_CustomTrackWidth );

        if( aMode == PNS::PNS_MODE_ROUTE_DIFF_PAIR )
            Add( ACT_SetDpDimensions );

        AppendSeparator();
        Add( PNS::TOOL_BASE::ACT_RouterOptions );

        AppendSeparator();
        Add( &m_zoomMenu );
        Add( &m_gridMenu );
    }

private:
    CONTEXT_MENU* create() const override
    {
        return new ROUTER_TOOL_MENU( m_board, m_frame, m_mode );
    }

    const BOARD* m_board;
    PCB_EDIT_FRAME& m_frame;
    PNS::ROUTER_MODE m_mode;
    TRACK_WIDTH_MENU m_widthMenu;
    ZOOM_MENU m_zoomMenu;
    GRID_MENU m_gridMenu;
};


ROUTER_TOOL::~ROUTER_TOOL()
{
    m_savedSettings.Save( GetSettings() );
}


bool ROUTER_TOOL::Init()
{
    m_savedSettings.Load( GetSettings() );
    return true;
}


void ROUTER_TOOL::Reset( RESET_REASON aReason )
{
    TOOL_BASE::Reset( aReason );
}


int ROUTER_TOOL::getDefaultWidth( int aNetCode )
{
    int w, d1, d2;

    getNetclassDimensions( aNetCode, w, d1, d2 );

    return w;
}


void ROUTER_TOOL::getNetclassDimensions( int aNetCode, int& aWidth,
                                         int& aViaDiameter, int& aViaDrill )
{
    BOARD_DESIGN_SETTINGS &bds = board()->GetDesignSettings();

    NETCLASSPTR netClass;
    NETINFO_ITEM* ni = board()->FindNet( aNetCode );

    if( ni )
    {
        wxString netClassName = ni->GetClassName();
        netClass = bds.m_NetClasses.Find( netClassName );
    }

    if( !netClass )
        netClass = bds.GetDefault();

    aWidth = netClass->GetTrackWidth();
    aViaDiameter = netClass->GetViaDiameter();
    aViaDrill = netClass->GetViaDrill();
}


void ROUTER_TOOL::handleCommonEvents( const TOOL_EVENT& aEvent )
{
#ifdef DEBUG
    if( aEvent.IsKeyPressed() )
    {
        switch( aEvent.KeyCode() )
        {
        case '0':
            wxLogTrace( "PNS", "saving drag/route log...\n" );
            m_router->DumpLog();
            break;
        }
    }
#endif
}


int ROUTER_TOOL::getStartLayer( const PNS::ITEM* aItem )
{
    int tl = getView()->GetTopLayer();

    if( m_startItem )
    {
        const LAYER_RANGE& ls = m_startItem->Layers();

        if( ls.Overlaps( tl ) )
            return tl;
        else
            return ls.Start();
    }

    return tl;
}


void ROUTER_TOOL::switchLayerOnViaPlacement()
{
    int al = frame()->GetActiveLayer();
    int cl = m_router->GetCurrentLayer();

    if( cl != al )
    {
        m_router->SwitchLayer( al );
    }

    OPT<int> newLayer = m_router->Sizes().PairedLayer( cl );

    if( !newLayer )
        newLayer = m_router->Sizes().GetLayerTop();

    m_router->SwitchLayer( *newLayer );
    frame()->SetActiveLayer( ToLAYER_ID( *newLayer ) );
}


static VIATYPE_T getViaTypeFromFlags( int aFlags )
{
    VIATYPE_T viaType = VIA_THROUGH;

    switch( aFlags & VIA_ACTION_FLAGS::VIA_MASK )
    {
    case VIA_ACTION_FLAGS::VIA:
        viaType = VIA_THROUGH;
        break;
    case VIA_ACTION_FLAGS::BLIND_VIA:
        viaType = VIA_BLIND_BURIED;
        break;
    case VIA_ACTION_FLAGS::MICROVIA:
        viaType = VIA_MICROVIA;
        break;
    default:
        wxASSERT_MSG( false, "Unhandled via type" );
    }

    return viaType;
}


int ROUTER_TOOL::onViaCommand( const TOOL_EVENT& aEvent )
{
    const int actViaFlags = aEvent.Parameter<intptr_t>();

    VIATYPE_T viaType = getViaTypeFromFlags( actViaFlags );
    const bool selectLayer = actViaFlags & VIA_ACTION_FLAGS::SELECT_LAYER;

    BOARD_DESIGN_SETTINGS& bds = board()->GetDesignSettings();

    const int layerCount = bds.GetCopperLayerCount();
    int currentLayer = m_router->GetCurrentLayer();
    PCB_LAYER_ID pairTop = frame()->GetScreen()->m_Route_Layer_TOP;
    PCB_LAYER_ID pairBottom = frame()->GetScreen()->m_Route_Layer_BOTTOM;

    PNS::SIZES_SETTINGS sizes = m_router->Sizes();

    // ask the user for a target layer
    PCB_LAYER_ID targetLayer = UNDEFINED_LAYER;

    if( selectLayer )
    {
        wxPoint dlgPosition = wxGetMousePosition();

        targetLayer = frame()->SelectLayer( static_cast<PCB_LAYER_ID>( currentLayer ),
                LSET::AllNonCuMask(), dlgPosition );
    }

    // fixme: P&S supports more than one fixed layer pair. Update the dialog?
    sizes.ClearLayerPairs();

    if( !m_router->IsPlacingVia() )
    {
        // Cannot place microvias or blind vias if not allowed (obvious)
        if( ( viaType == VIA_BLIND_BURIED ) && ( !bds.m_BlindBuriedViaAllowed ) )
        {
            DisplayError( frame(), _( "Blind/buried vias have to be enabled in the design settings." ) );
            return false;
        }

        if( ( viaType == VIA_MICROVIA ) && ( !bds.m_MicroViasAllowed ) )
        {
            DisplayError( frame(), _( "Microvias have to be enabled in the design settings." ) );
            return false;
        }

        // Can only place through vias on 2-layer boards
        if( ( viaType != VIA_THROUGH ) && ( layerCount <= 2 ) )
        {
            DisplayError( frame(), _( "Only through vias are allowed on 2 layer boards." ) );
            return false;
        }

        // Can only place microvias if we're on an outer layer, or directly adjacent to one
        if( ( viaType == VIA_MICROVIA ) && ( currentLayer > In1_Cu ) && ( currentLayer < layerCount - 2 ) )
        {
            DisplayError( frame(), _( "Microvias can be placed only between the outer layers " \
                                      "(F.Cu/B.Cu) and the ones directly adjacent to them." ) );
            return false;
        }
    }

    // Convert blind/buried via to a through hole one, if it goes through all layers
    if( viaType == VIA_BLIND_BURIED && ( ( currentLayer == B_Cu ) || ( currentLayer == F_Cu ) )
                                    && ( ( pairTop == B_Cu && pairBottom == F_Cu )
                                      || ( pairTop == F_Cu && pairBottom == B_Cu ) ) )
    {
        viaType = VIA_THROUGH;
    }

    switch( viaType )
    {
    case VIA_THROUGH:
        sizes.SetViaDiameter( bds.GetCurrentViaSize() );
        sizes.SetViaDrill( bds.GetCurrentViaDrill() );

        if( targetLayer != UNDEFINED_LAYER )
        {
            // go from the current layer to the chosen layer
            sizes.AddLayerPair( currentLayer, targetLayer );
        }
        else
        {
            // use the default layer pair
            sizes.AddLayerPair( pairTop, pairBottom );
        }
        break;

    case VIA_MICROVIA:
        sizes.SetViaDiameter( bds.GetCurrentMicroViaSize() );
        sizes.SetViaDrill( bds.GetCurrentMicroViaDrill() );

        wxASSERT_MSG( !selectLayer, "Unexpected select layer for microvia (microvia layers are implicit)" );

        if( currentLayer == F_Cu || currentLayer == In1_Cu )
        {
            // front-side microvia
            sizes.AddLayerPair( F_Cu, In1_Cu );
        }
        else if( currentLayer == B_Cu || currentLayer == layerCount - 2 )
        {
            // back-side microvia
            sizes.AddLayerPair( B_Cu, layerCount - 2 );
        }
        else
        {
            wxASSERT_MSG( false, "Invalid layer pair for microvia (must be on or adjacent to an outer layer)" );
        }
        break;

    case VIA_BLIND_BURIED:
        sizes.SetViaDiameter( bds.GetCurrentViaSize() );
        sizes.SetViaDrill( bds.GetCurrentViaDrill() );

        if( targetLayer != UNDEFINED_LAYER )
        {
            // go directly to the user specified layer
            sizes.AddLayerPair( currentLayer, targetLayer );
        }
        else
        {
            if( currentLayer == pairTop || currentLayer == pairBottom )
            {
                // the current layer is on the defined layer pair,
                // swap to the other side
                sizes.AddLayerPair( pairTop, pairBottom );
            }
            else
            {
                // the current layer is not part of the current layer pair,
                // so fallback and swap to the top layer of the pair by default
                sizes.AddLayerPair( pairTop, currentLayer );
            }
        }
        break;

    default:
        wxASSERT( false );
        break;
    }

    sizes.SetViaType( viaType );

    m_router->UpdateSizes( sizes );
    m_router->ToggleViaPlacement();

    updateEndItem( aEvent );

    m_router->Move( m_endSnapPoint, m_endItem );        // refresh

    return 0;
}


bool ROUTER_TOOL::prepareInteractive()
{
    int routingLayer = getStartLayer( m_startItem );

    if( !IsCopperLayer( routingLayer ) )
    {
        DisplayError( frame(), _( "Tracks on Copper layers only" ) );
        return false;
    }

    frame()->SetActiveLayer( ToLAYER_ID( routingLayer ) );

    // fixme: switch on invisible layer

    // for some reason I don't understand, GetNetclass() may return null sometimes...
    if( m_startItem && m_startItem->Net() >= 0 &&
        m_startItem->Parent() && m_startItem->Parent()->GetNetClass() )
    {
        highlightNet( true, m_startItem->Net() );
        // Update track width and via size shown in main toolbar comboboxes
        frame()->SetCurrentNetClass( m_startItem->Parent()->GetNetClass()->GetName() );
    }
    else
        frame()->SetCurrentNetClass( NETCLASS::Default );

    controls()->ForceCursorPosition( false );
    controls()->SetAutoPan( true );

    PNS::SIZES_SETTINGS sizes( m_router->Sizes() );

    sizes.Init( board(), m_startItem );
    sizes.AddLayerPair( frame()->GetScreen()->m_Route_Layer_TOP,
                        frame()->GetScreen()->m_Route_Layer_BOTTOM );
    m_router->UpdateSizes( sizes );

    if( !m_router->StartRouting( m_startSnapPoint, m_startItem, routingLayer ) )
    {
        DisplayError( frame(), m_router->FailureReason() );
        highlightNet( false );
        controls()->SetAutoPan( false );
        return false;
    }

    m_endItem = NULL;
    m_endSnapPoint = m_startSnapPoint;

    frame()->UndoRedoBlock( true );

    return true;
}


bool ROUTER_TOOL::finishInteractive()
{
    m_router->StopRouting();

    controls()->SetAutoPan( false );
    controls()->ForceCursorPosition( false );
    frame()->UndoRedoBlock( false );
    highlightNet( false );

    return true;
}


void ROUTER_TOOL::performRouting()
{
    if( !prepareInteractive() )
        return;

    while( OPT_TOOL_EVENT evt = Wait() )
    {
        // Don't crash if we missed an operation that cancelled routing.
        wxCHECK2( m_router->RoutingInProgress(), break );

        if( evt->IsMotion() )
        {
            m_router->SetOrthoMode( evt->Modifier( MD_CTRL ) );
            updateEndItem( *evt );
            m_router->Move( m_endSnapPoint, m_endItem );
        }
        else if( evt->IsClick( BUT_LEFT ) )
        {
            updateEndItem( *evt );
            bool needLayerSwitch = m_router->IsPlacingVia();

            if( m_router->FixRoute( m_endSnapPoint, m_endItem ) )
                break;

            if( needLayerSwitch )
                switchLayerOnViaPlacement();

            // Synchronize the indicated layer
            frame()->SetActiveLayer( ToLAYER_ID( m_router->GetCurrentLayer() ) );
            updateEndItem( *evt );
            m_router->Move( m_endSnapPoint, m_endItem );
            m_startItem = NULL;
        }
        else if( evt->IsAction( &ACT_SwitchPosture ) )
        {
            m_router->FlipPosture();
            updateEndItem( *evt );
            m_router->Move( m_endSnapPoint, m_endItem );        // refresh
        }
        else if( evt->IsAction( &PCB_ACTIONS::layerChanged ) )
        {
            m_router->SwitchLayer( frame()->GetActiveLayer() );
            updateEndItem( *evt );
            m_router->Move( m_endSnapPoint, m_endItem );        // refresh
        }
        else if( evt->IsAction( &ACT_EndTrack ) )
        {
            bool still_routing = true;
            while( still_routing )
                still_routing = m_router->FixRoute( m_endSnapPoint, m_endItem );
            break;
        }
        else if( TOOL_EVT_UTILS::IsCancelInteractive( *evt )
                 || evt->IsUndoRedo()
                 || evt->IsAction( &PCB_ACTIONS::routerInlineDrag ) )
            break;
    }

    finishInteractive();
}


int ROUTER_TOOL::DpDimensionsDialog( const TOOL_EVENT& aEvent )
{
    Activate();

    PNS::SIZES_SETTINGS sizes = m_router->Sizes();
    DIALOG_PNS_DIFF_PAIR_DIMENSIONS settingsDlg( frame(), sizes );

    if( settingsDlg.ShowModal() )
    {
        m_router->UpdateSizes( sizes );
        m_savedSizes = sizes;
    }

    return 0;
}


int ROUTER_TOOL::SettingsDialog( const TOOL_EVENT& aEvent )
{
    Activate();

    DIALOG_PNS_SETTINGS settingsDlg( frame(), m_router->Settings() );

    if( settingsDlg.ShowModal() )
    {
        m_savedSettings = m_router->Settings();
    }

    return 0;
}


void ROUTER_TOOL::setTransitions()
{
    Go( &ROUTER_TOOL::RouteSingleTrace, PCB_ACTIONS::routerActivateSingle.MakeEvent() );
    Go( &ROUTER_TOOL::RouteDiffPair, PCB_ACTIONS::routerActivateDiffPair.MakeEvent() );
    Go( &ROUTER_TOOL::DpDimensionsDialog, PCB_ACTIONS::routerActivateDpDimensionsDialog.MakeEvent() );
    Go( &ROUTER_TOOL::SettingsDialog, PCB_ACTIONS::routerActivateSettingsDialog.MakeEvent() );
    Go( &ROUTER_TOOL::InlineDrag, PCB_ACTIONS::routerInlineDrag.MakeEvent() );

    Go( &ROUTER_TOOL::onViaCommand, ACT_PlaceThroughVia.MakeEvent() );
    Go( &ROUTER_TOOL::onViaCommand, ACT_PlaceBlindVia.MakeEvent() );
    Go( &ROUTER_TOOL::onViaCommand, ACT_PlaceMicroVia.MakeEvent() );
    Go( &ROUTER_TOOL::onViaCommand, ACT_SelLayerAndPlaceThroughVia.MakeEvent() );
    Go( &ROUTER_TOOL::onViaCommand, ACT_SelLayerAndPlaceBlindVia.MakeEvent() );

    // TODO is not this redundant? the same actions can be used for menus and hotkeys
    Go( &ROUTER_TOOL::SettingsDialog, ACT_RouterOptions.MakeEvent() );
    Go( &ROUTER_TOOL::DpDimensionsDialog, ACT_SetDpDimensions.MakeEvent() );

    Go( &ROUTER_TOOL::CustomTrackWidthDialog, ACT_CustomTrackWidth.MakeEvent() );
    Go( &ROUTER_TOOL::onTrackViaSizeChanged, PCB_ACTIONS::trackViaSizeChanged.MakeEvent() );
}


int ROUTER_TOOL::RouteSingleTrace( const TOOL_EVENT& aEvent )
{
    frame()->SetToolID( ID_TRACK_BUTT, wxCURSOR_PENCIL, _( "Route Track" ) );
    return mainLoop( PNS::PNS_MODE_ROUTE_SINGLE );
}


int ROUTER_TOOL::RouteDiffPair( const TOOL_EVENT& aEvent )
{
    frame()->SetToolID( ID_TRACK_BUTT, wxCURSOR_PENCIL, _( "Router Differential Pair" ) );
    return mainLoop( PNS::PNS_MODE_ROUTE_DIFF_PAIR );
}

void ROUTER_TOOL::breakTrack()
{
    if ( m_startItem->OfKind( PNS::ITEM::SEGMENT_T ) )
    {
        m_router->BreakSegment( m_startItem, m_startSnapPoint );
    }
}

int ROUTER_TOOL::mainLoop( PNS::ROUTER_MODE aMode )
{
    PCB_EDIT_FRAME* frame = getEditFrame<PCB_EDIT_FRAME>();
    BOARD* board = getModel<BOARD>();

    // Deselect all items
    m_toolMgr->RunAction( PCB_ACTIONS::selectionClear, true );

    Activate();

    m_router->SetMode( aMode );

    VIEW_CONTROLS* ctls = getViewControls();
    ctls->ShowCursor( true );
    ctls->ForceCursorPosition( false );
    m_startSnapPoint = ctls->GetCursorPosition();

    std::unique_ptr<ROUTER_TOOL_MENU> ctxMenu( new ROUTER_TOOL_MENU( board, *frame, aMode ) );
    SetContextMenu( ctxMenu.get() );

    // Main loop: keep receiving events
    while( OPT_TOOL_EVENT evt = Wait() )
    {
        if( TOOL_EVT_UTILS::IsCancelInteractive( *evt ) )
        {
            break; // Finish
        }
        else if( evt->Action() == TA_UNDO_REDO_PRE )
        {
            m_router->ClearWorld();
        }
        else if( evt->Action() == TA_UNDO_REDO_POST || evt->Action() == TA_MODEL_CHANGE )
        {
            m_router->SyncWorld();
        }
        else if( evt->IsMotion() )
        {
            updateStartItem( *evt );
        }
        else if( evt->IsAction( &PCB_ACTIONS::dragFreeAngle ) )
        {
            updateStartItem( *evt );
            performDragging( PNS::DM_ANY | PNS::DM_FREE_ANGLE );
        }
        else if( evt->IsAction( &PCB_ACTIONS::drag45Degree ) )
        {
            updateStartItem( *evt );
            performDragging( PNS::DM_ANY );
        }
        else if( evt->IsAction( &PCB_ACTIONS::breakTrack ) )
        {
            updateStartItem( *evt );
            breakTrack( );
        }
        else if( evt->IsClick( BUT_LEFT ) || evt->IsAction( &ACT_NewTrack ) )
        {
            updateStartItem( *evt );

            if( evt->Modifier( MD_CTRL ) )
                performDragging( PNS::DM_ANY );
            else
                performRouting();
        }
        else if( evt->IsAction( &ACT_PlaceThroughVia ) )
        {
            m_toolMgr->RunAction( PCB_ACTIONS::layerToggle, true );
        }
    }

    frame->SetNoToolSelected();
    SetContextMenu( nullptr );

    // Store routing settings till the next invocation
    m_savedSettings = m_router->Settings();
    m_savedSizes = m_router->Sizes();

    return 0;
}


void ROUTER_TOOL::performDragging( int aMode )
{
    VIEW_CONTROLS* ctls = getViewControls();

    if( m_startItem && m_startItem->IsLocked() )
    {
        if( !IsOK( frame(), _( "The item is locked. Do you want to continue?" ) ) )
            return;
    }

    bool dragStarted = m_router->StartDragging( m_startSnapPoint, m_startItem, aMode );

    if( !dragStarted )
        return;

    if( m_startItem && m_startItem->Net() >= 0 )
        highlightNet( true, m_startItem->Net() );

    ctls->SetAutoPan( true );

    frame()->UndoRedoBlock( true );

    while( OPT_TOOL_EVENT evt = Wait() )
    {
        ctls->ForceCursorPosition( false );

        if( evt->IsMotion() )
        {
            updateEndItem( *evt );
            m_router->Move( m_endSnapPoint, m_endItem );
        }
        else if( evt->IsClick( BUT_LEFT ) )
        {
            if( m_router->FixRoute( m_endSnapPoint, m_endItem ) )
                break;
        }
        else if( TOOL_EVT_UTILS::IsCancelInteractive( *evt )
                 || evt->IsUndoRedo() )
            break;

        handleCommonEvents( *evt );
    }

    if( m_router->RoutingInProgress() )
        m_router->StopRouting();

    m_startItem = nullptr;

    frame()->UndoRedoBlock( false );
    ctls->SetAutoPan( false );
    ctls->ForceCursorPosition( false );
    highlightNet( false );
}


void ROUTER_TOOL::NeighboringSegmentFilter( const VECTOR2I& aPt, GENERAL_COLLECTOR& aCollector )
{
    /* If the collection contains a trivial line corner (two connected segments)
     * or a non-fanout-via (a via with no more than two connected segments), then
     * trim the collection down to a single item (which one won't matter since
     * they're all connected).
     */

    // First make sure we've got something that *might* match.
    int vias = aCollector.CountType( PCB_VIA_T );
    int traces = aCollector.CountType( PCB_TRACE_T );

    if( vias > 1 || traces > 2 || vias + traces < 1 )
        return;

    // Fetch first TRACK (via or trace) as our reference
    TRACK* reference = nullptr;

    for( int i = 0; !reference && i < aCollector.GetCount(); i++ )
        reference = dynamic_cast<TRACK*>( aCollector[i] );

    int refNet = reference->GetNetCode();

    wxPoint refPoint;
    STATUS_FLAGS flags = reference->IsPointOnEnds( wxPoint( aPt.x, aPt.y ), -1 );

    if( flags & STARTPOINT )
        refPoint = reference->GetStart();
    else if( flags & ENDPOINT )
        refPoint = reference->GetEnd();
    else
        return;

    // Check all items to ensure that they are TRACKs which are co-terminus
    // with the reference, and on the same net.  Ignore markers.
    for( int i = 0; i < aCollector.GetCount(); i++ )
    {
        BOARD_ITEM* item = static_cast<BOARD_ITEM*>( aCollector[i] );

        if( item->Type() == PCB_MARKER_T )
            continue;

        TRACK* neighbor = dynamic_cast<TRACK*>( item );

        if( !neighbor || neighbor->GetNetCode() != refNet )
            return;

        if( neighbor->GetStart() != refPoint && neighbor->GetEnd() != refPoint )
            return;
    }

    // Selection meets criteria; trim it to the reference item.
    for( int i = aCollector.GetCount() - 1; i >= 0; i-- )
    {
        if( dynamic_cast<TRACK*>( aCollector[i] ) != reference )
            aCollector.Remove( i );
    }
}


bool ROUTER_TOOL::CanInlineDrag()
{
    m_toolMgr->RunAction( PCB_ACTIONS::selectionCursor, true, NeighboringSegmentFilter );
    const auto& selection = m_toolMgr->GetTool<SELECTION_TOOL>()->GetSelection();

    if( selection.Size() == 1 )
    {
        const BOARD_CONNECTED_ITEM* item = static_cast<const BOARD_CONNECTED_ITEM*>( selection.Front() );

        if( item->Type() == PCB_TRACE_T || item->Type() == PCB_VIA_T )
            return true;
    }

    return false;
}


int ROUTER_TOOL::InlineDrag( const TOOL_EVENT& aEvent )
{
    const auto& selection = m_toolMgr->GetTool<SELECTION_TOOL>()->GetSelection();

    if( selection.Empty() )
        m_toolMgr->RunAction( PCB_ACTIONS::selectionCursor, true, NeighboringSegmentFilter );

    if( selection.Size() != 1 )
        return 0;

    const BOARD_CONNECTED_ITEM* item = static_cast<const BOARD_CONNECTED_ITEM*>( selection.Front() );

    if( item->Type() != PCB_TRACE_T && item->Type() != PCB_VIA_T )
        return 0;

    Activate();

    m_toolMgr->RunAction( PCB_ACTIONS::selectionClear, true );
    m_router->SyncWorld();
    m_startItem = m_router->GetWorld()->FindItemByParent( item );

    if( m_startItem && m_startItem->IsLocked() )
    {
        if( !IsOK( frame(), _( "The item is locked. Do you want to continue?" ) ) )
            return false;
    }

    VECTOR2I p0 = controls()->GetCursorPosition();

    int dragMode = aEvent.Parameter<int64_t> ();

    bool dragStarted = m_router->StartDragging( p0, m_startItem, dragMode );

    if( !dragStarted )
        return 0;

    controls()->ShowCursor( true );
    controls()->ForceCursorPosition( false );
    controls()->SetAutoPan( true );
    frame()->UndoRedoBlock( true );

    while( OPT_TOOL_EVENT evt = Wait() )
    {
        if( evt->IsCancel() )
        {
            break;
        }
        else if( evt->IsMotion() || evt->IsDrag( BUT_LEFT ) )
        {
            updateEndItem( *evt );
            m_router->Move( m_endSnapPoint, m_endItem );
        }
        else if( evt->IsMouseUp( BUT_LEFT ) || evt->IsClick( BUT_LEFT ) )
        {
            updateEndItem( *evt );
            m_router->FixRoute( m_endSnapPoint, m_endItem );
            break;
        }
    }

    if( m_router->RoutingInProgress() )
        m_router->StopRouting();

    frame()->UndoRedoBlock( false );

    return 0;
}


int ROUTER_TOOL::CustomTrackWidthDialog( const TOOL_EVENT& aEvent )
{
    BOARD_DESIGN_SETTINGS& bds = board()->GetDesignSettings();
    DIALOG_TRACK_VIA_SIZE sizeDlg( frame(), bds );

    if( sizeDlg.ShowModal() )
    {
        bds.UseCustomTrackViaSize( true );
        m_toolMgr->RunAction( PCB_ACTIONS::trackViaSizeChanged );
    }

    return 0;
}


int ROUTER_TOOL::onTrackViaSizeChanged( const TOOL_EVENT& aEvent )
{
    PNS::SIZES_SETTINGS sizes( m_router->Sizes() );
    sizes.ImportCurrent( board()->GetDesignSettings() );
    m_router->UpdateSizes( sizes );

    return 0;
}