/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
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#include <svx/svdotext.hxx>
#include <svx/svdoutl.hxx>
#include <editeng/outlobj.hxx>
#include <editeng/editobj.hxx>
#include <editeng/overflowingtxt.hxx>
#include <textchainflow.hxx>
#include <sal/log.hxx>

TextChainFlow::TextChainFlow(SdrTextObj *pChainTarget)
    : mpTargetLink(pChainTarget)
{
    SAL_INFO("svx.chaining", "[TEXTCHAINFLOW] Creating a new TextChainFlow");

    mpTextChain = mpTargetLink->GetTextChain();
    mpNextLink = mpTargetLink->GetNextLinkInChain();

    bUnderflow = bOverflow = false;

    mbOFisUFinduced = false;

    mpOverflChText = nullptr;
    mpUnderflChText = nullptr;

    mbPossiblyCursorOut = false;
}


TextChainFlow::~TextChainFlow()
{
    mpOverflChText.reset();
    mpUnderflChText.reset();
}

void TextChainFlow::impSetFlowOutlinerParams(SdrOutliner *, SdrOutliner *)
{
    // Nothing to do if not in editing mode
}

/*
 * Check for overflow in the state of pFlowOutl.
 * If pParamOutl is not NULL sets some parameters from there.
 * This is useful in case the outliner is not set for overflow
 * (e.g. in editing mode we check for overflow in drawing outl but
 *  parameters come from editing outliner)
*/
void TextChainFlow::impCheckForFlowEvents(SdrOutliner *pFlowOutl, SdrOutliner *pParamOutl)
{
    bool bOldUpdateMode = pFlowOutl->IsUpdateLayout();

    // XXX: This could be reorganized moving most of this stuff inside EditingTextChainFlow
    if (pParamOutl != nullptr)
    {
        // We need this since it's required to check overflow
        pFlowOutl->SetUpdateLayout(true);

        // XXX: does this work if you do it before setting the text? Seems so.
        impSetFlowOutlinerParams(pFlowOutl, pParamOutl);
    }

    bool bIsPageOverflow = pFlowOutl->IsPageOverflow();

    // NOTE: overflow and underflow cannot be both true
    bOverflow = bIsPageOverflow && mpNextLink;
    bUnderflow = !bIsPageOverflow &&  mpNextLink && mpNextLink->HasText();

    // Get old state on whether to merge para-s or not
    // NOTE: We handle UF/OF using the _old_ state. The new one is simply saved
    bool bMustMergeParaAmongLinks = GetTextChain()->GetIsPartOfLastParaInNextLink(mpTargetLink);

    // Set (Non)OverflowingTxt here (if any)

    // If we had an underflow before we have to deep merge paras anyway
    bool bMustMergeParaOF = bMustMergeParaAmongLinks || mbOFisUFinduced;

    mpOverflChText.reset( bOverflow ?
                     new OFlowChainedText(pFlowOutl, bMustMergeParaOF) :
                     nullptr );

    // Set current underflowing text (if any)
    mpUnderflChText.reset( bUnderflow ?
                      new UFlowChainedText(pFlowOutl, bMustMergeParaAmongLinks) :
                      nullptr );

    // Reset update mode // Reset it here because we use WriteRTF (needing updatemode = true) in the two constructors above
    if (!bOldUpdateMode) // Reset only if the old value was false
        pFlowOutl->SetUpdateLayout(bOldUpdateMode);

    // NOTE: Must be called after mp*ChText and b*flow have been set but before mbOFisUFinduced is reset
    impUpdateCursorInfo();

    // To check whether an overflow is underflow induced or not (useful in cursor checking)
    mbOFisUFinduced = bUnderflow;
}

void TextChainFlow::impUpdateCursorInfo()
{
    // XXX: Maybe we can get rid of mbOFisUFinduced by not allowing handling of more than one event by the same TextChainFlow
    // if this is not an OF triggered during an UF

    mbPossiblyCursorOut = bOverflow;

    if(mbPossiblyCursorOut ) {
        maOverflowPosSel = mpOverflChText->GetOverflowPointSel();
        ESelection aSelAtUFTime = GetTextChain()->GetPreChainingSel(GetLinkTarget());
        // Might be an invalid selection if the cursor at UF time was before
        //   the (possibly UF-induced) Overflowing point but we don't use it in that case
        maPostChainingSel = ESelection(aSelAtUFTime.nStartPara-maOverflowPosSel.nStartPara,
                                       aSelAtUFTime.nStartPos-maOverflowPosSel.nStartPos );
    }

    // XXX: It may not be necessary anymore to keep this method separated from EditingTextChainFlow::impBroadcastCursorInfo
}

void TextChainFlow::CheckForFlowEvents(SdrOutliner *pFlowOutl)
{
    impCheckForFlowEvents(pFlowOutl, nullptr);
}


bool TextChainFlow::IsOverflow() const
{
    return bOverflow;
}

bool TextChainFlow::IsUnderflow() const
{
    return bUnderflow;
}


// XXX: In editing mode you need to get "underflowing" text from editing outliner, so it's kinda separated from the drawing one!

// XXX:Would it be possible to unify underflow and its possibly following overflow?
void TextChainFlow::ExecuteUnderflow(SdrOutliner *pOutl)
{
    //GetTextChain()->SetNilChainingEvent(mpTargetLink, true);
    // making whole text
    // merges underflowing text with the one in the next box
    std::optional<OutlinerParaObject> pNewText = mpUnderflChText->CreateMergedUnderflowParaObject(pOutl, mpNextLink->GetOutlinerParaObject());

    // Set the other box empty; it will be replaced by the rest of the text if overflow occurs
    if (!mpTargetLink->GetPreventChainable())
        mpNextLink->NbcSetOutlinerParaObject(pOutl->GetEmptyParaObject());

    // We store the size since NbcSetOutlinerParaObject can change it
    //Size aOldSize = pOutl->GetMaxAutoPaperSize();

    // This should not be done in editing mode!! //XXX
    if (!mpTargetLink->IsInEditMode())
    {
        mpTargetLink->NbcSetOutlinerParaObject(pNewText);
    }

    // Restore size and set new text
    //pOutl->SetMaxAutoPaperSize(aOldSize); // XXX (it seems to be working anyway without this)
    pOutl->SetText(*pNewText);

    //GetTextChain()->SetNilChainingEvent(mpTargetLink, false);

    // Check for new overflow
    CheckForFlowEvents(pOutl);
}

void TextChainFlow::ExecuteOverflow(SdrOutliner *pNonOverflOutl, SdrOutliner *pOverflOutl)
{
    //GetTextChain()->SetNilChainingEvent(mpTargetLink, true);
    // Leave only non overflowing text
    impLeaveOnlyNonOverflowingText(pNonOverflOutl);

    // Transfer of text to next link
    if (!mpTargetLink->GetPreventChainable() ) // we don't transfer text while dragging because of resizing
    {
        impMoveChainedTextToNextLink(pOverflOutl);
    }

    //GetTextChain()->SetNilChainingEvent(mpTargetLink, false);
}

void TextChainFlow::impLeaveOnlyNonOverflowingText(SdrOutliner *pNonOverflOutl)
{
    std::optional<OutlinerParaObject> pNewText = mpOverflChText->RemoveOverflowingText(pNonOverflOutl);

    SAL_INFO("svx.chaining", "[TEXTCHAINFLOW - OF] SOURCE box set to "
             << pNewText->GetTextObject().GetParagraphCount() << " paras");

    // adds it to current outliner anyway (useful in static decomposition)
    pNonOverflOutl->SetText(*pNewText);

    mpTargetLink->NbcSetOutlinerParaObject(std::move(pNewText));
    // For some reason the paper size is lost after last instruction, so we set it.
    pNonOverflOutl->SetPaperSize(Size(pNonOverflOutl->GetPaperSize().Width(),
                                      pNonOverflOutl->GetTextHeight()));

}

void TextChainFlow::impMoveChainedTextToNextLink(SdrOutliner *pOverflOutl)
{
    // prevent copying text in same box
    if ( mpNextLink ==  mpTargetLink ) {
        SAL_INFO("svx.chaining", "[CHAINING] Trying to copy text for next link in same object");
        return;
    }

    std::optional<OutlinerParaObject> pNewText =
        mpOverflChText->InsertOverflowingText(pOverflOutl,
                                              mpNextLink->GetOutlinerParaObject());
    SAL_INFO("svx.chaining", "[TEXTCHAINFLOW - OF] DEST box set to "
             << pNewText->GetTextObject().GetParagraphCount() << " paras");

    if (pNewText)
        mpNextLink->NbcSetOutlinerParaObject(std::move(pNewText));

    // Set Deep Merge status
    SAL_INFO("svx.chaining", "[DEEPMERGE] Setting deepMerge to "
             << mpOverflChText->IsLastParaInterrupted());
    GetTextChain()->SetIsPartOfLastParaInNextLink(
                          mpTargetLink,
                          mpOverflChText->IsLastParaInterrupted());
}

SdrTextObj *TextChainFlow::GetLinkTarget() const
{
    return mpTargetLink;
}

TextChain *TextChainFlow::GetTextChain() const
{
    return mpTextChain;
}

// EditingTextChainFlow

EditingTextChainFlow::EditingTextChainFlow(SdrTextObj *pLinkTarget) :
    TextChainFlow(pLinkTarget)
{
    SAL_INFO("svx.chaining", "[TEXTCHAINFLOW] Creating a new EditingTextChainFlow");
}

void EditingTextChainFlow::CheckForFlowEvents(SdrOutliner *pFlowOutl)
{
    // if this is editing outliner no need to set parameters
    if (pFlowOutl == GetLinkTarget()->mpEditingOutliner)
        impCheckForFlowEvents(pFlowOutl, nullptr);
    else
        impCheckForFlowEvents(pFlowOutl, GetLinkTarget()->mpEditingOutliner);

    // Broadcast events for cursor handling
    impBroadcastCursorInfo();
}

void EditingTextChainFlow::impLeaveOnlyNonOverflowingText(SdrOutliner *pNonOverflOutl)
{
    mpOverflChText->RemoveOverflowingText(pNonOverflOutl);
    //impSetTextForEditingOutliner(pNewText); //XXX: Don't call it since we do everything with NonOverflowingText::ToParaObject // XXX: You may need this for Underflow

    // XXX: I'm not sure whether we need this (after all operations such as Paste don't change this - as far as I understand)
    //GetLinkTarget()->NbcSetOutlinerParaObject(pNewText);
}

void EditingTextChainFlow::impSetFlowOutlinerParams(SdrOutliner *pFlowOutl, SdrOutliner *pParamOutl)
{
    // Set right size for overflow
    pFlowOutl->SetMaxAutoPaperSize(pParamOutl->GetMaxAutoPaperSize());
    pFlowOutl->SetMinAutoPaperSize(pParamOutl->GetMinAutoPaperSize());
    pFlowOutl->SetPaperSize(pParamOutl->GetPaperSize());
}

void EditingTextChainFlow::impBroadcastCursorInfo() const
{
    ESelection aPreChainingSel = GetTextChain()->GetPreChainingSel(GetLinkTarget()) ;

    // Test whether the cursor is out of the box.
    bool bCursorOut = mbPossiblyCursorOut && maOverflowPosSel < aPreChainingSel;

    // NOTE: I handled already the stuff for the comments below. They will be kept temporarily till stuff settles down.
    // Possibility: 1) why don't we stop passing the actual event to the TextChain and instead we pass
    //              the overflow pos and mbPossiblyCursorOut
    //              2) We pass the current selection before anything happens and we make impBroadcastCursorInfo compute it.


    if (bCursorOut) {
            //maCursorEvent = CursorChainingEvent::TO_NEXT_LINK;
            GetTextChain()->SetPostChainingSel(GetLinkTarget(), maPostChainingSel);
            GetTextChain()->SetCursorEvent(GetLinkTarget(), CursorChainingEvent::TO_NEXT_LINK);
    } else {
        //maCursorEvent = CursorChainingEvent::UNCHANGED;
        GetTextChain()->SetPostChainingSel(GetLinkTarget(), aPreChainingSel);
        GetTextChain()->SetCursorEvent(GetLinkTarget(), CursorChainingEvent::UNCHANGED);
    }


}

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