// $Revision: 1.4 $
// Copyright (c) 1994-1995 Taligent, Inc.  All rights reserved.

#ifndef TaligentSamples_STANDARDSELECTSTATES
#include "StandardSelectStates.h"
#endif

TaligentTypeExtensionMacro_Abstract(TSetSelectState);

TSetSelectState::TSetSelectState(MTextRepresentation* textRepresentation, 
    TTextChunkIteratorReference& iteratorReference)
    : TSelectState(textRepresentation, iteratorReference)
{
}

TSetSelectState::~TSetSelectState()
{
}
    
void
TSetSelectState::Setup(const TInsertionOffset& initialOffset, const TTextArea& initialArea)
{
    TTextArea area;
    ComputeSelection(initialOffset, area);
    SetAnchor(area);
}

void
TSetSelectState::Track(const TInsertionOffset& trackingOffset, TTextArea& resultArea)
{
    ComputeSelection(trackingOffset, resultArea);
    ExtendArea(resultArea);
}

void
TSetSelectState::SetAnchor(const TTextArea& area)
{
    fAnchor = area;
}

// TextRegions cannot contain insertion points or zero-length TextRanges.
// So we can't use the computation operations defined on regions, and have
// to hack it ourselves.  And unfortunately, there is no union operation
// defined on ranges either, so we have to hack that ourselves too.

void
TSetSelectState::ExtendArea(TTextArea& resultArea)
{
    if (resultArea != fAnchor) {
        TTextRange anchorRange;
        if (fAnchor.IsInsertionPoint()) {
            TInsertionOffset insertionOffset;
            fAnchor.GetInsertionOffset(insertionOffset);
            anchorRange.SetBeginAndEnd(insertionOffset, insertionOffset);
        } else {
            TTextRegion region;
            fAnchor.GetRegion(region);
            region.GetBounds(anchorRange);
        }

        TTextRange resultRange;
        if (resultArea.IsInsertionPoint()) {
            TInsertionOffset insertionOffset;
            resultArea.GetInsertionOffset(insertionOffset);
            resultRange.SetBeginAndEnd(insertionOffset, insertionOffset);
        } else {
            TTextRegion region;
            resultArea.GetRegion(region);
            region.GetBounds(resultRange);
        }
                
        if (anchorRange.GetBegin() < resultRange.GetBegin()) {
            resultRange.SetBegin(anchorRange.GetBegin());
        }
        if (anchorRange.GetEnd() > resultRange.GetEnd()) {
            resultRange.SetEnd(anchorRange.GetEnd());
        }

        resultArea = resultRange;
    }
}

// =========================================================================

TaligentTypeExtensionMacro_Abstract(TExtendSelectState);

TExtendSelectState::TExtendSelectState(MTextRepresentation* textRepresentation, 
    TTextChunkIteratorReference& iteratorReference)
    : TSetSelectState(textRepresentation, iteratorReference)
{
}

TExtendSelectState::~TExtendSelectState()
{
}
    
void
TExtendSelectState::Setup(const TInsertionOffset& initialOffset, const TTextArea& initialArea)
{
    if (initialArea.IsInsertionPoint()) {
        SetAnchor(initialArea);
    } else {
        TTextRegion region;
        initialArea.GetRegion(region);
        TTextRange range;
        region.GetBounds(range);
    
        TTextOffset lowAnchor = range.GetBegin();
        TTextOffset highAnchor = range.GetEnd();
        TTextOffset midAnchor = (TTextOffset)(((long)lowAnchor + (long)highAnchor) / 2);

        TTextOffset offset = initialOffset.GetOffset();
        TTextOffset anchor = lowAnchor;
        if (offset < midAnchor) {
            anchor = highAnchor;
        }

        SetAnchor(TTextArea(TInsertionOffset(anchor, TInsertionOffset::kBeforeOffset)));
    }
}