/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2019 KiCad Developers, see AUTHORS.txt for contributors.
 *
 * 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 2
 * 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, you may find one here:
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 * or you may search the http://www.gnu.org website for the version 2 license,
 * or you may write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */


#include <ee_actions.h>
#include <core/typeinfo.h>
#include <sch_item.h>
#include <ee_selection_tool.h>
#include <sch_base_frame.h>
#include <sch_edit_frame.h>
#include <lib_edit_frame.h>
#include <viewlib_frame.h>
#include <sch_component.h>
#include <sch_sheet.h>
#include <sch_field.h>
#include <view/view.h>
#include <view/view_controls.h>
#include <view/view_group.h>
#include <preview_items/selection_area.h>
#include <tool/tool_event.h>
#include <tool/tool_manager.h>
#include <tools/sch_wire_bus_tool.h>
#include <ee_collectors.h>
#include <painter.h>
#include <eeschema_id.h>
#include <menus_helpers.h>
#include <ee_hotkeys.h>

// Selection tool actions
TOOL_ACTION EE_ACTIONS::selectionActivate( "eeschema.InteractiveSelection",
        AS_GLOBAL, 0, "", "",       // No description, not shown anywhere
        nullptr, AF_ACTIVATE );

TOOL_ACTION EE_ACTIONS::selectionTool( "eeschema.InteractiveSelection.selectionTool",
        AS_GLOBAL, 0, _( "Select item(s)" ), "",
        cursor_xpm, AF_ACTIVATE );

TOOL_ACTION EE_ACTIONS::selectNode( "eeschema.InteractiveSelection.SelectNode",
        AS_GLOBAL, TOOL_ACTION::LegacyHotKey( HK_SELECT_NODE ),
        _( "Select Node" ), _( "Select a connection item under the cursor" ) );

TOOL_ACTION EE_ACTIONS::selectConnection( "eeschema.InteractiveSelection.SelectConnection",
        AS_GLOBAL, TOOL_ACTION::LegacyHotKey( HK_SELECT_CONNECTION ),
        _( "Select Connection" ), _( "Select a complete connection" ) );

TOOL_ACTION EE_ACTIONS::selectionMenu( "eeschema.InteractiveSelection.SelectionMenu",
        AS_GLOBAL, 0, "", "" );    // No description, it is not supposed to be shown anywhere

TOOL_ACTION EE_ACTIONS::addItemToSel( "eeschema.InteractiveSelection.AddItemToSel",
        AS_GLOBAL, 0, "", "" );    // No description, it is not supposed to be shown anywhere

TOOL_ACTION EE_ACTIONS::addItemsToSel( "eeschema.InteractiveSelection.AddItemsToSel",
        AS_GLOBAL, 0, "", "" );    // No description, it is not supposed to be shown anywhere

TOOL_ACTION EE_ACTIONS::removeItemFromSel( "eeschema.InteractiveSelection.RemoveItemFromSel",
        AS_GLOBAL, 0, "", "" );    // No description, it is not supposed to be shown anywhere

TOOL_ACTION EE_ACTIONS::removeItemsFromSel( "eeschema.InteractiveSelection.RemoveItemsFromSel",
        AS_GLOBAL, 0, "", "" );    // No description, it is not supposed to be shown anywhere

TOOL_ACTION EE_ACTIONS::clearSelection( "eeschema.InteractiveSelection.ClearSelection",
        AS_GLOBAL, 0, "", "" );    // No description, it is not supposed to be shown anywhere


SELECTION_CONDITION EE_CONDITIONS::Empty = [] (const SELECTION& aSelection )
{
    return aSelection.Empty();
};


SELECTION_CONDITION EE_CONDITIONS::Idle = [] (const SELECTION& aSelection )
{
    return ( !aSelection.Front() || aSelection.Front()->GetEditFlags() == 0 );
};


SELECTION_CONDITION EE_CONDITIONS::IdleSelection = [] (const SELECTION& aSelection )
{
    return ( aSelection.Front() && aSelection.Front()->GetEditFlags() == 0 );
};


SELECTION_CONDITION EE_CONDITIONS::SingleSymbol = [] (const SELECTION& aSel )
{
    if( aSel.GetSize() == 1 )
    {
        SCH_COMPONENT* comp = dynamic_cast<SCH_COMPONENT*>( aSel.Front() );

        if( comp )
        {
            auto partRef = comp->GetPartRef().lock();
            return !partRef || !partRef->IsPower();
        }
    }

    return false;
};


SELECTION_CONDITION EE_CONDITIONS::SingleDeMorganSymbol = [] ( const SELECTION& aSel )
{
    if( aSel.GetSize() == 1 )
    {
        SCH_COMPONENT* comp = dynamic_cast<SCH_COMPONENT*>( aSel.Front() );

        if( comp )
        {
            auto partRef = comp->GetPartRef().lock();
            return partRef && partRef->HasConversion();
        }
    }

    return false;
};


SELECTION_CONDITION EE_CONDITIONS::SingleMultiUnitSymbol = [] ( const SELECTION& aSel )
{
    if( aSel.GetSize() == 1 )
    {
        SCH_COMPONENT* comp = dynamic_cast<SCH_COMPONENT*>( aSel.Front() );

        if( comp )
        {
            auto partRef = comp->GetPartRef().lock();
            return partRef && partRef->GetUnitCount() >= 2;
        }
    }

    return false;
};


#define HITTEST_THRESHOLD_PIXELS 5


EE_SELECTION_TOOL::EE_SELECTION_TOOL() :
        TOOL_INTERACTIVE( "eeschema.InteractiveSelection" ),
        m_frame( nullptr ),
        m_additive( false ),
        m_subtractive( false ),
        m_multiple( false ),
        m_skip_heuristics( false ),
        m_isLibEdit( false ),
        m_isLibView( false ),
        m_unit( 0 ),
        m_convert( 0 ),
        m_menu( *this )
{
}


EE_SELECTION_TOOL::~EE_SELECTION_TOOL()
{
    getView()->Remove( &m_selection );
}

using E_C = EE_CONDITIONS;

bool EE_SELECTION_TOOL::Init()
{
    m_frame = getEditFrame<SCH_BASE_FRAME>();

    LIB_VIEW_FRAME* libViewFrame = dynamic_cast<LIB_VIEW_FRAME*>( m_frame );
    LIB_EDIT_FRAME* libEditFrame = dynamic_cast<LIB_EDIT_FRAME*>( m_frame );

    if( libEditFrame )
    {
        m_isLibEdit = true;
        m_unit = libEditFrame->GetUnit();
        m_convert = libEditFrame->GetConvert();
    }
    else
        m_isLibView = libViewFrame != nullptr;


    static KICAD_T wireOrBusTypes[] = { SCH_LINE_LOCATE_WIRE_T, SCH_LINE_LOCATE_BUS_T, EOT };

    auto wireSelection =      E_C::MoreThan( 0 ) && E_C::OnlyType( SCH_LINE_LOCATE_WIRE_T );
    auto busSelection =       E_C::MoreThan( 0 ) && E_C::OnlyType( SCH_LINE_LOCATE_BUS_T );
    auto wireOrBusSelection = E_C::MoreThan( 0 ) && E_C::OnlyTypes( wireOrBusTypes );
    auto sheetSelection =     E_C::Count( 1 )    && E_C::OnlyType( SCH_SHEET_T );
    auto schEditCondition = [this] ( const SELECTION& aSel ) {
        return !m_isLibEdit && !m_isLibView;
    };
    auto belowRootSheetCondition = [this] ( const SELECTION& aSel ) {
        return !m_isLibEdit && !m_isLibView && g_CurrentSheet->Last() != g_RootSheet;
    };
    auto havePartCondition = [ this ] ( const SELECTION& sel ) {
        return m_isLibEdit && ( (LIB_EDIT_FRAME*) m_frame )->GetCurPart();
    };

    auto& menu = m_menu.GetMenu();

    menu.AddItem( EE_ACTIONS::enterSheet,         sheetSelection && EE_CONDITIONS::Idle, 1 );
    menu.AddItem( EE_ACTIONS::explicitCrossProbe, sheetSelection && EE_CONDITIONS::Idle, 1 );
    menu.AddItem( EE_ACTIONS::leaveSheet,         belowRootSheetCondition, 1 );

    menu.AddSeparator( EE_CONDITIONS::Empty, 100 );
    menu.AddItem( EE_ACTIONS::startWire,          schEditCondition && EE_CONDITIONS::Empty, 100 );
    menu.AddItem( EE_ACTIONS::startBus,           schEditCondition && EE_CONDITIONS::Empty, 100 );

    menu.AddSeparator( SCH_WIRE_BUS_TOOL::IsDrawingWire, 100 );
    menu.AddItem( EE_ACTIONS::finishWire,         SCH_WIRE_BUS_TOOL::IsDrawingWire, 100 );

    menu.AddSeparator( SCH_WIRE_BUS_TOOL::IsDrawingBus, 100 );
    menu.AddItem( EE_ACTIONS::finishBus,          SCH_WIRE_BUS_TOOL::IsDrawingBus, 100 );

    menu.AddSeparator( EE_CONDITIONS::NotEmpty, 200 );
    menu.AddItem( EE_ACTIONS::selectConnection,   wireOrBusSelection && EE_CONDITIONS::Idle, 250 );
    menu.AddItem( EE_ACTIONS::addJunction,        wireOrBusSelection && EE_CONDITIONS::Idle, 250 );
    menu.AddItem( EE_ACTIONS::addLabel,           wireOrBusSelection && EE_CONDITIONS::Idle, 250 );
    menu.AddItem( EE_ACTIONS::addGlobalLabel,     wireOrBusSelection && EE_CONDITIONS::Idle, 250 );
    menu.AddItem( EE_ACTIONS::addHierLabel,       wireOrBusSelection && EE_CONDITIONS::Idle, 250 );
    menu.AddItem( EE_ACTIONS::breakWire,          wireSelection && EE_CONDITIONS::Idle, 250 );
    menu.AddItem( EE_ACTIONS::breakBus,           busSelection && EE_CONDITIONS::Idle, 250 );
    menu.AddItem( EE_ACTIONS::addSheetPin,        sheetSelection && EE_CONDITIONS::Idle, 250 );
    menu.AddItem( EE_ACTIONS::addImportedSheetPin,sheetSelection && EE_CONDITIONS::Idle, 250 );

    menu.AddSeparator( havePartCondition && EE_CONDITIONS::Empty, 400 );
    menu.AddItem( EE_ACTIONS::symbolProperties,   havePartCondition && EE_CONDITIONS::Empty, 400 );
    menu.AddItem( EE_ACTIONS::pinTable,           havePartCondition && EE_CONDITIONS::Empty, 400 );

    menu.AddSeparator( SELECTION_CONDITIONS::ShowAlways, 1000 );
    m_menu.AddStandardSubMenus( m_frame );

    return true;
}


void EE_SELECTION_TOOL::Reset( RESET_REASON aReason )
{
    m_frame = getEditFrame<SCH_BASE_FRAME>();

    if( aReason == TOOL_BASE::MODEL_RELOAD )
    {
        // Remove pointers to the selected items from containers without changing their
        // properties (as they are already deleted while a new sheet is loaded)
        m_selection.Clear();
        getView()->GetPainter()->GetSettings()->SetHighlight( false );

        LIB_EDIT_FRAME* libEditFrame = dynamic_cast<LIB_EDIT_FRAME*>( m_frame );
        LIB_VIEW_FRAME* libViewFrame = dynamic_cast<LIB_VIEW_FRAME*>( m_frame );

        if( libEditFrame )
        {
            m_isLibEdit = true;
            m_unit = libEditFrame->GetUnit();
            m_convert = libEditFrame->GetConvert();
        }
        else
            m_isLibView = libViewFrame != nullptr;
    }
    else
        // Restore previous properties of selected items and remove them from containers
        ClearSelection();

    // Reinsert the VIEW_GROUP, in case it was removed from the VIEW
    getView()->Remove( &m_selection );
    getView()->Add( &m_selection );
}


int EE_SELECTION_TOOL::UpdateMenu( const TOOL_EVENT& aEvent )
{
    ACTION_MENU*      actionMenu = aEvent.Parameter<ACTION_MENU*>();
    CONDITIONAL_MENU* conditionalMenu = dynamic_cast<CONDITIONAL_MENU*>( actionMenu );

    if( conditionalMenu )
        conditionalMenu->Evaluate( m_selection );

    if( actionMenu )
        actionMenu->UpdateAll();

    return 0;
}


int EE_SELECTION_TOOL::Main( const TOOL_EVENT& aEvent )
{
    const KICAD_T movableItems[] =
    {
        SCH_MARKER_T,
        SCH_JUNCTION_T,
        SCH_NO_CONNECT_T,
        SCH_BUS_BUS_ENTRY_T,
        SCH_BUS_WIRE_ENTRY_T,
        SCH_LINE_T,
        SCH_BITMAP_T,
        SCH_TEXT_T,
        SCH_LABEL_T,
        SCH_GLOBAL_LABEL_T,
        SCH_HIER_LABEL_T,
        SCH_FIELD_T,
        SCH_COMPONENT_T,
        SCH_SHEET_PIN_T,
        SCH_SHEET_T,
        EOT
    };

    // Main loop: keep receiving events
    while( OPT_TOOL_EVENT evt = Wait() )
    {
        // Should selected items be added to the current selection or
        // become the new selection (discarding previously selected items)
        m_additive = evt->Modifier( MD_SHIFT );

        // Should selected items be REMOVED from the current selection?
        // This will be ignored if the SHIFT modifier is pressed
        m_subtractive = !m_additive && evt->Modifier( MD_CTRL );

        // Is the user requesting that the selection list include all possible
        // items without removing less likely selection candidates
        m_skip_heuristics = !!evt->Modifier( MD_ALT );

        // Single click? Select single object
        if( evt->IsClick( BUT_LEFT ) )
        {
            // JEY TODO: this is a hack, but I can't figure out why it's needed to
            // keep from getting the first click when running the Place Symbol tool.
            if( m_frame->GetToolId() != ID_NO_TOOL_SELECTED )
                continue;

            if( evt->Modifier( MD_CTRL ) && dynamic_cast<SCH_EDIT_FRAME*>( m_frame ) )
            {
                m_toolMgr->RunAction( EE_ACTIONS::highlightNet, true );
            }
            else
            {
                // If no modifier keys are pressed, clear the selection
                if( !m_additive )
                    ClearSelection();

                SelectPoint( evt->Position());
            }
        }

        // right click? if there is any object - show the context menu
        else if( evt->IsClick( BUT_RIGHT ) )
        {
            bool selectionCancelled = false;

            if( m_selection.Empty() )
            {
                SelectPoint( evt->Position(), EE_COLLECTOR::AllItems, &selectionCancelled );
                m_selection.SetIsHover( true );
            }

            if( !selectionCancelled )
                m_menu.ShowContextMenu( m_selection );
        }

        // double click? Display the properties window
        else if( evt->IsDblClick( BUT_LEFT ) )
        {
            if( m_selection.Empty() )
                SelectPoint( evt->Position());

            EDA_ITEM* item = m_selection.Front();

            if( item && item->Type() == SCH_SHEET_T )
                m_toolMgr->RunAction( EE_ACTIONS::enterSheet );
            else
                m_toolMgr->RunAction( EE_ACTIONS::properties );
        }

        // drag with LMB? Select multiple objects (or at least draw a selection box) or drag them
        else if( evt->IsDrag( BUT_LEFT ) )
        {
            bool empty = m_selection.Empty();

            // selection is empty? try to start dragging the item under the point where drag started
            if( empty )
            {
                m_selection = RequestSelection( movableItems );
                empty = m_selection.Empty();
            }

            // selection STILL empty? attempt a rectangle multi-selection
            if( m_additive || m_subtractive || empty || m_frame->GetDragAlwaysSelects() )
            {
                selectMultiple();
            }
            else
            {
                // Check if dragging has started within any of selected items bounding box
                if( selectionContains( evt->Position() ) )
                {
                    // Yes -> run the move tool and wait till it finishes
                    m_toolMgr->InvokeTool( "eeschema.InteractiveMove" );
                }
                else
                {
                    // No -> clear the selection list
                    ClearSelection();
                }
            }
        }

        // context sub-menu selection?  Handle unit selection or bus unfolding
        else if( evt->Category() == TC_COMMAND && evt->Action() == TA_CONTEXT_MENU_CHOICE )
        {
            if( evt->GetCommandId().get() >= ID_POPUP_SCH_SELECT_UNIT_CMP
                && evt->GetCommandId().get() <= ID_POPUP_SCH_SELECT_UNIT_CMP_MAX )
            {
                SCH_COMPONENT* component = dynamic_cast<SCH_COMPONENT*>( m_selection.Front() );
                int unit = evt->GetCommandId().get() - ID_POPUP_SCH_SELECT_UNIT_CMP;

                if( component )
                    static_cast<SCH_EDIT_FRAME*>( m_frame )->SelectUnit( component, unit );
            }
            else if( evt->GetCommandId().get() >= ID_POPUP_SCH_UNFOLD_BUS
                     && evt->GetCommandId().get() <= ID_POPUP_SCH_UNFOLD_BUS_END )
            {
                wxString* net = new wxString( *evt->Parameter<wxString*>() );
                m_toolMgr->RunAction( EE_ACTIONS::unfoldBus, true, net );
            }

        }

        else if( evt->IsAction( &ACTIONS::cancelInteractive ) || evt->IsCancel() )
        {
            ClearSelection();
            m_toolMgr->RunAction( EE_ACTIONS::clearHighlight, true );
        }

        else if( evt->Action() == TA_UNDO_REDO_PRE )
        {
            ClearSelection();
        }

        else if( evt->Action() == TA_CONTEXT_MENU_CLOSED )
        {
            m_menu.CloseContextMenu( evt );
        }

        else
            m_toolMgr->PassEvent();
    }

    // This tool is supposed to be active forever
    assert( false );

    return 0;
}


SELECTION& EE_SELECTION_TOOL::GetSelection()
{
    return m_selection;
}


EDA_ITEM* EE_SELECTION_TOOL::SelectPoint( const VECTOR2I& aWhere, const KICAD_T* aFilterList,
                                           bool* aSelectionCancelledFlag, bool aCheckLocked )
{
    EDA_ITEM*    start;
    EE_COLLECTOR collector;

    if( m_isLibEdit )
        start = static_cast<LIB_EDIT_FRAME*>( m_frame )->GetCurPart();
    else
        start = m_frame->GetScreen()->GetDrawItems();

    // Empty schematics have no draw items
    if( !start )
        return nullptr;

    collector.m_Threshold = KiROUND( getView()->ToWorld( HITTEST_THRESHOLD_PIXELS ) );
    collector.Collect( start, aFilterList, (wxPoint) aWhere, m_unit, m_convert );

    bool anyCollected = collector.GetCount() != 0;

    // Remove unselectable items
    for( int i = collector.GetCount() - 1; i >= 0; --i )
    {
        if( !selectable( collector[ i ] ) )
            collector.Remove( i );

        if( aCheckLocked && collector[ i ]->IsLocked() )
            collector.Remove( i );
    }

    m_selection.ClearReferencePoint();

    // Apply some ugly heuristics to avoid disambiguation menus whenever possible
    if( collector.GetCount() > 1 && !m_skip_heuristics )
    {
        guessSelectionCandidates( collector, aWhere );
    }

    // If still more than one item we're going to have to ask the user.
    if( collector.GetCount() > 1 )
    {
        collector.m_MenuTitle =  _( "Clarify Selection" );
        // Must call selectionMenu via RunAction() to avoid event-loop contention
        m_toolMgr->RunAction( EE_ACTIONS::selectionMenu, true, &collector );

        if( collector.m_MenuCancelled )
        {
            if( aSelectionCancelledFlag )
                *aSelectionCancelledFlag = true;

            return nullptr;
        }
    }

    if( collector.GetCount() == 1 )
    {
        EDA_ITEM* item = collector[ 0 ];

        toggleSelection( item );
        return item;
    }

    if( !m_additive && anyCollected )
        ClearSelection();

    return nullptr;
}


void EE_SELECTION_TOOL::guessSelectionCandidates( EE_COLLECTOR& collector, const VECTOR2I& aPos )
{
    // There are certain parent/child and enclosure combinations that can be handled
    // automatically.

    // Prefer a non-sheet to a sheet
    for( int i = 0; collector.GetCount() == 2 && i < 2; ++i )
    {
        EDA_ITEM* item = collector[ i ];
        EDA_ITEM* other = collector[ ( i + 1 ) % 2 ];

        if( item->Type() != SCH_SHEET_T && other->Type() == SCH_SHEET_T )
            collector.Remove( other );
    }

    // Prefer a symbol to a pin
    for( int i = 0; collector.GetCount() == 2 && i < 2; ++i )
    {
        EDA_ITEM* item = collector[ i ];
        EDA_ITEM* other = collector[ ( i + 1 ) % 2 ];

        if( item->Type() == SCH_COMPONENT_T && other->Type() == SCH_PIN_T )
            collector.Remove( other );
    }

    // Prefer an exact hit to a sloppy one
    for( int i = 0; collector.GetCount() == 2 && i < 2; ++i )
    {
        EDA_ITEM* item = collector[ i ];
        EDA_ITEM* other = collector[ ( i + 1 ) % 2 ];

        if( item->HitTest( (wxPoint) aPos, 0 ) && !other->HitTest( (wxPoint) aPos, 0 ) )
            collector.Remove( other );
    }

    // Prefer a field to a symbol
    for( int i = 0; collector.GetCount() == 2 && i < 2; ++i )
    {
        EDA_ITEM* item = collector[ i ];
        EDA_ITEM* other = collector[ ( i + 1 ) % 2 ];

        if( item->Type() == SCH_FIELD_T && other->Type() == SCH_COMPONENT_T )
            collector.Remove( other );
    }
}


SELECTION& EE_SELECTION_TOOL::RequestSelection( const KICAD_T aFilterList[] )
{
    // Filter an existing selection
    if( !m_selection.Empty() )
    {
        for( int i = m_selection.GetSize() - 1; i >= 0; --i )
        {
            EDA_ITEM* item = (EDA_ITEM*) m_selection.GetItem( i );

            if( !item->IsType( aFilterList ) )
                toggleSelection( item );
        }

    }

    // If nothing was selected, or we filtered everything out, do a hover selection
    if( m_selection.Empty() )
    {
        VECTOR2D cursorPos = getViewControls()->GetCursorPosition( true );

        ClearSelection();
        SelectPoint( cursorPos, aFilterList );
        m_selection.SetIsHover( true );
        m_selection.ClearReferencePoint();
    }

    VECTOR2I refP( 0, 0 );

    if( m_selection.Size() > 0 )
    {
        if( m_isLibEdit )
            refP = static_cast<LIB_ITEM*>( m_selection.GetTopLeftItem() )->GetPosition();
        else
            refP = static_cast<SCH_ITEM*>( m_selection.GetTopLeftItem() )->GetPosition();
    }

    m_selection.SetReferencePoint( refP );

    return m_selection;
}


bool EE_SELECTION_TOOL::selectMultiple()
{
    bool cancelled = false;     // Was the tool cancelled while it was running?
    m_multiple = true;          // Multiple selection mode is active
    KIGFX::VIEW* view = getView();

    KIGFX::PREVIEW::SELECTION_AREA area;
    view->Add( &area );

    while( OPT_TOOL_EVENT evt = Wait() )
    {
        if( evt->IsAction( &ACTIONS::cancelInteractive ) || evt->IsActivate() || evt->IsCancel() )
        {
            cancelled = true;
            break;
        }

        if( evt->IsDrag( BUT_LEFT ) )
        {
            // Start drawing a selection box
            area.SetOrigin( evt->DragOrigin() );
            area.SetEnd( evt->Position() );
            area.SetAdditive( m_additive );
            area.SetSubtractive( m_subtractive );

            view->SetVisible( &area, true );
            view->Update( &area );
            getViewControls()->SetAutoPan( true );
        }

        if( evt->IsMouseUp( BUT_LEFT ) )
        {
            getViewControls()->SetAutoPan( false );

            // End drawing the selection box
            view->SetVisible( &area, false );

            // Mark items within the selection box as selected
            std::vector<KIGFX::VIEW::LAYER_ITEM_PAIR> selectedItems;

            // Filter the view items based on the selection box
            BOX2I selectionBox = area.ViewBBox();
            view->Query( selectionBox, selectedItems );         // Get the list of selected items

            std::vector<KIGFX::VIEW::LAYER_ITEM_PAIR>::iterator it, it_end;

            int width = area.GetEnd().x - area.GetOrigin().x;
            int height = area.GetEnd().y - area.GetOrigin().y;

            /* Selection mode depends on direction of drag-selection:
             * Left > Right : Select objects that are fully enclosed by selection
             * Right > Left : Select objects that are crossed by selection
             */
            bool windowSelection = width >= 0 ? true : false;

            if( view->IsMirroredX() )
                windowSelection = !windowSelection;

            // Construct an EDA_RECT to determine EDA_ITEM selection
            EDA_RECT selectionRect( (wxPoint)area.GetOrigin(), wxSize( width, height ) );

            selectionRect.Normalize();

            for( it = selectedItems.begin(), it_end = selectedItems.end(); it != it_end; ++it )
            {
                EDA_ITEM* item = static_cast<EDA_ITEM*>( it->first );

                if( !item || !selectable( item ) )
                    continue;

                if( item->HitTest( selectionRect, windowSelection ) )
                {
                    if( m_subtractive )
                        unselect( item );
                    else
                        select( item );
                }
            }

            // Inform other potentially interested tools
            if( !m_selection.Empty() )
                m_toolMgr->ProcessEvent( EVENTS::SelectedEvent );

            break;  // Stop waiting for events
        }
    }

    getViewControls()->SetAutoPan( false );

    // Stop drawing the selection box
    view->Remove( &area );
    m_multiple = false;         // Multiple selection mode is inactive

    if( !cancelled )
        m_selection.ClearReferencePoint();

    return cancelled;
}


static KICAD_T nodeTypes[] =
{
    SCH_LINE_LOCATE_WIRE_T,
    SCH_LINE_LOCATE_BUS_T,
    SCH_BUS_WIRE_ENTRY_T,
    SCH_BUS_BUS_ENTRY_T,
    SCH_LABEL_T,
    SCH_HIER_LABEL_T,
    SCH_GLOBAL_LABEL_T,
    SCH_SHEET_PIN_T,
    SCH_JUNCTION_T,
    EOT
};


EDA_ITEM* EE_SELECTION_TOOL::GetNode( VECTOR2I aPosition )
{
    EE_COLLECTOR collector;

    int thresholdMax = KiROUND( getView()->ToWorld( HITTEST_THRESHOLD_PIXELS ) );

    for( int threshold : { 0, thresholdMax/2, thresholdMax } )
    {
        collector.m_Threshold = threshold;
        collector.Collect( m_frame->GetScreen()->GetDrawItems(), nodeTypes, (wxPoint) aPosition );

        if( collector.GetCount() > 0 )
            break;
    }

    return collector.GetCount() ? collector[ 0 ] : nullptr;
}


int EE_SELECTION_TOOL::SelectNode( const TOOL_EVENT& aEvent )
{
    VECTOR2I cursorPos = getViewControls()->GetCursorPosition( !aEvent.Modifier( MD_ALT ) );

    SelectPoint( cursorPos, nodeTypes  );

    return 0;
}


int EE_SELECTION_TOOL::SelectConnection( const TOOL_EVENT& aEvent )
{
    static KICAD_T wiresAndBusses[] = { SCH_LINE_LOCATE_WIRE_T, SCH_LINE_LOCATE_BUS_T, EOT };

    RequestSelection( wiresAndBusses );

    if( m_selection.Empty() )
        return 0;

    SCH_LINE* line = (SCH_LINE*) m_selection.Front();
    EDA_ITEMS items;

    m_frame->GetScreen()->ClearDrawingState();
    m_frame->GetScreen()->MarkConnections( line );

    for( EDA_ITEM* item = m_frame->GetScreen()->GetDrawItems(); item; item = item->Next() )
    {
        if( item->GetFlags() & CANDIDATE )
            select( item );
    }

    if( m_selection.GetSize() > 1 )
        m_toolMgr->ProcessEvent( EVENTS::SelectedEvent );

    return 0;
}


int EE_SELECTION_TOOL::AddItemToSel( const TOOL_EVENT& aEvent )
{
    AddItemToSel( aEvent.Parameter<EDA_ITEM*>() );
    return 0;
}


void EE_SELECTION_TOOL::AddItemToSel( EDA_ITEM* aItem, bool aQuietMode )
{
    if( aItem )
    {
        select( aItem );

        // Inform other potentially interested tools
        if( !aQuietMode )
            m_toolMgr->ProcessEvent( EVENTS::SelectedEvent );
    }
}


int EE_SELECTION_TOOL::AddItemsToSel( const TOOL_EVENT& aEvent )
{
    AddItemsToSel( aEvent.Parameter<EDA_ITEMS*>(), false );
    return 0;
}


void EE_SELECTION_TOOL::AddItemsToSel( EDA_ITEMS* aList, bool aQuietMode )
{
    if( aList )
    {
        for( EDA_ITEM* item : *aList )
            select( item );

        // Inform other potentially interested tools
        if( !aQuietMode )
            m_toolMgr->ProcessEvent( EVENTS::SelectedEvent );
    }
}


int EE_SELECTION_TOOL::RemoveItemFromSel( const TOOL_EVENT& aEvent )
{
    RemoveItemFromSel( aEvent.Parameter<EDA_ITEM*>() );
    return 0;
}


void EE_SELECTION_TOOL::RemoveItemFromSel( EDA_ITEM* aItem, bool aQuietMode )
{
    if( aItem )
    {
        unselect( aItem );

        // Inform other potentially interested tools
        if( !aQuietMode )
            m_toolMgr->ProcessEvent( EVENTS::UnselectedEvent );
    }
}


int EE_SELECTION_TOOL::RemoveItemsFromSel( const TOOL_EVENT& aEvent )
{
    RemoveItemsFromSel( aEvent.Parameter<EDA_ITEMS*>(), false );
    return 0;
}


void EE_SELECTION_TOOL::RemoveItemsFromSel( EDA_ITEMS* aList, bool aQuietMode )
{
    if( aList )
    {
        for( EDA_ITEM* item : *aList )
            unselect( item );

        // Inform other potentially interested tools
        if( !aQuietMode )
            m_toolMgr->ProcessEvent( EVENTS::UnselectedEvent );
    }
}


void EE_SELECTION_TOOL::BrightenItem( EDA_ITEM* aItem )
{
    highlight( aItem, BRIGHTENED );
}


void EE_SELECTION_TOOL::UnbrightenItem( EDA_ITEM* aItem )
{
    unhighlight( aItem, BRIGHTENED );
}


int EE_SELECTION_TOOL::ClearSelection( const TOOL_EVENT& aEvent )
{
    ClearSelection();

    return 0;
}


void EE_SELECTION_TOOL::RebuildSelection()
{
    m_selection.Clear();

    EDA_ITEM* start = nullptr;

    if( m_isLibEdit )
        start = static_cast<LIB_EDIT_FRAME*>( m_frame )->GetCurPart();
    else
        start = m_frame->GetScreen()->GetDrawItems();

    INSPECTOR_FUNC inspector = [&] ( EDA_ITEM* item, void* testData )
    {
        if( item->IsSelected() )
            select( item );

        return SEARCH_CONTINUE;
    };

    EDA_ITEM::IterateForward( start, inspector, nullptr, EE_COLLECTOR::AllItems );
}


int EE_SELECTION_TOOL::SelectionMenu( const TOOL_EVENT& aEvent )
{
    EE_COLLECTOR* collector = aEvent.Parameter<EE_COLLECTOR*>();

    if( !doSelectionMenu( collector ) )
        collector->m_MenuCancelled = true;

    return 0;
}


bool EE_SELECTION_TOOL::doSelectionMenu( EE_COLLECTOR* aCollector )
{
    EDA_ITEM*   current = nullptr;
    ACTION_MENU menu;

    int limit = std::min( MAX_SELECT_ITEM_IDS, aCollector->GetCount() );

    for( int i = 0; i < limit; ++i )
    {
        wxString text;
        EDA_ITEM* item = ( *aCollector )[i];
        text = item->GetSelectMenuText( m_frame->GetUserUnits() );

        wxString menuText = wxString::Format("&%d. %s", i + 1, text );
        menu.Add( menuText, i + 1, item->GetMenuImage() );
    }

    if( aCollector->m_MenuTitle.Length() )
        menu.SetTitle( aCollector->m_MenuTitle );

    menu.SetIcon( info_xpm );
    menu.DisplayTitle( true );
    SetContextMenu( &menu, CMENU_NOW );

    while( OPT_TOOL_EVENT evt = Wait() )
    {
        if( evt->Action() == TA_CONTEXT_MENU_UPDATE )
        {
            if( current )
                unhighlight( current, BRIGHTENED );

            int id = *evt->GetCommandId();

            // User has pointed an item, so show it in a different way
            if( id > 0 && id <= limit )
            {
                current = ( *aCollector )[id - 1];
                highlight( current, BRIGHTENED );
            }
            else
            {
                current = NULL;
            }
        }
        else if( evt->Action() == TA_CONTEXT_MENU_CHOICE )
        {
            if( current )
                unhighlight( current, BRIGHTENED );

            OPT<int> id = evt->GetCommandId();

            // User has selected an item, so this one will be returned
            if( id && ( *id > 0 ) )
                current = ( *aCollector )[*id - 1];
            else
                current = NULL;

            break;
        }

        getView()->UpdateItems();
        m_frame->GetCanvas()->Refresh();
    }

    if( current )
    {
        unhighlight( current, BRIGHTENED );

        getView()->UpdateItems();
        m_frame->GetCanvas()->Refresh();

        aCollector->Empty();
        aCollector->Append( current );
        return true;
    }

    return false;
}


bool EE_SELECTION_TOOL::selectable( const EDA_ITEM* aItem, bool checkVisibilityOnly ) const
{
    // NOTE: in the future this is where eeschema layer/itemtype visibility will be handled

    switch( aItem->Type() )
    {
    case SCH_PIN_T:
        if( !static_cast<const SCH_PIN*>( aItem )->IsVisible() && !m_frame->GetShowAllPins() )
            return false;
        break;

    case LIB_PART_T:    // In libedit we do not want to select the symbol itself.
        return false;

    case LIB_PIN_T:
    {
        LIB_EDIT_FRAME* editFrame = (LIB_EDIT_FRAME*) m_frame;
        LIB_PIN*        pin = (LIB_PIN*) aItem;

        if( ( pin->GetUnit() && pin->GetUnit() != editFrame->GetUnit() )
         || ( pin->GetConvert() && pin->GetConvert() != editFrame->GetConvert() ) )
        {
            // Specific rules for pins:
            // - do not select pins in other units when synchronized pin edit mode is disabled
            // - do not select pins in other units when units are not interchangeable
            // - in other cases verify if the pin belongs to the requested DeMorgan variant
            if( !editFrame->SynchronizePins()
                || editFrame->GetCurPart()->UnitsLocked()
                || ( pin->GetConvert() && pin->GetConvert() != editFrame->GetConvert() ) )
            {
                return false;
            }
        }
        break;
    }
    case SCH_MARKER_T:  // Always selectable
        return true;

    default:            // Suppress warnings
        break;
    }

    return true;
}


void EE_SELECTION_TOOL::ClearSelection()
{
    if( m_selection.Empty() )
        return;

    while( m_selection.GetSize() )
        unhighlight( (EDA_ITEM*) m_selection.Front(), SELECTED, &m_selection );

    getView()->Update( &m_selection );

    m_selection.SetIsHover( false );
    m_selection.ClearReferencePoint();

    // Inform other potentially interested tools
    m_toolMgr->ProcessEvent( EVENTS::ClearedEvent );
}


void EE_SELECTION_TOOL::toggleSelection( EDA_ITEM* aItem, bool aForce )
{
    if( aItem->IsSelected() )
    {
        unselect( aItem );

        // Inform other potentially interested tools
        m_toolMgr->ProcessEvent( EVENTS::UnselectedEvent );
    }
    else
    {
        if( !m_additive )
            ClearSelection();

        // Prevent selection of invisible or inactive items
        if( aForce || selectable( aItem ) )
        {
            select( aItem );

            // Inform other potentially interested tools
            m_toolMgr->ProcessEvent( EVENTS::SelectedEvent );
        }
    }

    if( m_frame )
        m_frame->GetGalCanvas()->ForceRefresh();
}


void EE_SELECTION_TOOL::select( EDA_ITEM* aItem )
{
    highlight( aItem, SELECTED, &m_selection );
}


void EE_SELECTION_TOOL::unselect( EDA_ITEM* aItem )
{
    unhighlight( aItem, SELECTED, &m_selection );
}


void EE_SELECTION_TOOL::highlight( EDA_ITEM* aItem, int aMode, SELECTION* aGroup )
{
    KICAD_T itemType = aItem->Type();

    if( aMode == SELECTED )
        aItem->SetSelected();
    else if( aMode == BRIGHTENED )
        aItem->SetBrightened();

    if( aGroup )
        aGroup->Add( aItem );

    // Highlight pins and fields.  (All the other component children are currently only
    // represented in the LIB_PART and will inherit the settings of the parent component.)
    if( itemType == SCH_COMPONENT_T )
    {
        SCH_PINS& pins = static_cast<SCH_COMPONENT*>( aItem )->GetPins();

        for( SCH_PIN& pin : pins )
        {
            if( aMode == SELECTED )
                pin.SetSelected();
            else if( aMode == BRIGHTENED )
                pin.SetBrightened();
        }

        std::vector<SCH_FIELD*> fields;
        static_cast<SCH_COMPONENT*>( aItem )->GetFields( fields, false );

        for( SCH_FIELD* field : fields )
        {
            if( aMode == SELECTED )
                field->SetSelected();
            else if( aMode == BRIGHTENED )
                field->SetBrightened();
        }
    }
    else if( itemType == SCH_SHEET_T )
    {
        SCH_SHEET_PINS& pins = static_cast<SCH_SHEET*>( aItem )->GetPins();

        for( SCH_SHEET_PIN& pin : pins )
        {
            if( aMode == SELECTED )
                pin.SetSelected();
            else if( aMode == BRIGHTENED )
                pin.SetBrightened();
        }
    }

    if( itemType == SCH_PIN_T || itemType == SCH_FIELD_T || itemType == SCH_SHEET_PIN_T )
        getView()->Update( aItem->GetParent() );
    else
        getView()->Update( aItem );
}


void EE_SELECTION_TOOL::unhighlight( EDA_ITEM* aItem, int aMode, SELECTION* aGroup )
{
    KICAD_T itemType = aItem->Type();

    if( aMode == SELECTED )
        aItem->ClearSelected();
    else if( aMode == BRIGHTENED )
        aItem->ClearBrightened();

    if( aGroup )
        aGroup->Remove( aItem );

    // Unhighlight pins and fields.  (All the other component children are currently only
    // represented in the LIB_PART.)
    if( itemType == SCH_COMPONENT_T )
    {
        SCH_PINS& pins = static_cast<SCH_COMPONENT*>( aItem )->GetPins();

        for( SCH_PIN& pin : pins )
        {
            if( aMode == SELECTED )
                pin.ClearSelected();
            else if( aMode == BRIGHTENED )
                pin.ClearBrightened();
        }

        std::vector<SCH_FIELD*> fields;
        static_cast<SCH_COMPONENT*>( aItem )->GetFields( fields, false );

        for( SCH_FIELD* field : fields )
        {
            if( aMode == SELECTED )
                field->ClearSelected();
            else if( aMode == BRIGHTENED )
                field->ClearBrightened();
        }
    }
    else if( itemType == SCH_SHEET_T )
    {
        SCH_SHEET_PINS& pins = static_cast<SCH_SHEET*>( aItem )->GetPins();

        for( SCH_SHEET_PIN& pin : pins )
        {
            if( aMode == SELECTED )
                pin.ClearSelected();
            else if( aMode == BRIGHTENED )
                pin.ClearBrightened();
        }
    }

    if( itemType == SCH_PIN_T || itemType == SCH_FIELD_T || itemType == SCH_SHEET_PIN_T )
        getView()->Update( aItem->GetParent() );
    else
        getView()->Update( aItem );
}


bool EE_SELECTION_TOOL::selectionContains( const VECTOR2I& aPoint ) const
{
    const unsigned GRIP_MARGIN = 20;
    VECTOR2I margin = getView()->ToWorld( VECTOR2I( GRIP_MARGIN, GRIP_MARGIN ), false );

    // Check if the point is located within any of the currently selected items bounding boxes
    for( auto item : m_selection )
    {
        BOX2I itemBox = item->ViewBBox();
        itemBox.Inflate( margin.x, margin.y );    // Give some margin for gripping an item

        if( itemBox.Contains( aPoint ) )
            return true;
    }

    return false;
}


void EE_SELECTION_TOOL::setTransitions()
{
    Go( &EE_SELECTION_TOOL::UpdateMenu,          ACTIONS::updateMenu.MakeEvent() );

    Go( &EE_SELECTION_TOOL::Main,                EE_ACTIONS::selectionActivate.MakeEvent() );
    Go( &EE_SELECTION_TOOL::SelectNode,          EE_ACTIONS::selectNode.MakeEvent() );
    Go( &EE_SELECTION_TOOL::SelectConnection,    EE_ACTIONS::selectConnection.MakeEvent() );
    Go( &EE_SELECTION_TOOL::ClearSelection,      EE_ACTIONS::clearSelection.MakeEvent() );

    Go( &EE_SELECTION_TOOL::AddItemToSel,        EE_ACTIONS::addItemToSel.MakeEvent() );
    Go( &EE_SELECTION_TOOL::AddItemsToSel,       EE_ACTIONS::addItemsToSel.MakeEvent() );
    Go( &EE_SELECTION_TOOL::RemoveItemFromSel,   EE_ACTIONS::removeItemFromSel.MakeEvent() );
    Go( &EE_SELECTION_TOOL::RemoveItemsFromSel,  EE_ACTIONS::removeItemsFromSel.MakeEvent() );
    Go( &EE_SELECTION_TOOL::SelectionMenu,       EE_ACTIONS::selectionMenu.MakeEvent() );
}