/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * This file is part of the LibreOffice project.

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * 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 .

 */

#include <textchain.hxx>

#include <textchaincursor.hxx>

#include <svx/svdedxv.hxx>

#include <svx/svdoutl.hxx>

#include <vcl/event.hxx>

// XXX: Possible duplication of code in behavior with stuff in ImpEditView (or ImpEditEngine) and OutlinerView

// XXX: We violate Demeter's Law several times here, I'm afraid

TextChainCursorManager::TextChainCursorManager(SdrObjEditView *pEditView, const SdrTextObj *pTextObj) :

    mpEditView(pEditView),

    mpTextObj(pTextObj),

    mbHandlingDel(false)

{

    assert(mpEditView);

    assert(mpTextObj);

}

bool TextChainCursorManager::HandleKeyEvent( const KeyEvent& rKEvt )

{

    ESelection aNewSel;

    CursorChainingEvent aCursorEvent;

    // check what the cursor/event situation looks like

    bool bCompletelyHandled = false;

    impDetectEvent(rKEvt, aCursorEvent, aNewSel, bCompletelyHandled);

    if (aCursorEvent == CursorChainingEvent::NULL_EVENT)

        return false;

    else {

        HandleCursorEvent(aCursorEvent, aNewSel);

        // return value depends on the situation we are in

        return bCompletelyHandled;

    }

}

void TextChainCursorManager::impDetectEvent(const KeyEvent& rKEvt,

                                            CursorChainingEvent& rOutCursorEvt,

                                            ESelection& rOutSel,

                                            bool& rOutHandled)

{

    SdrOutliner *pOutl = mpEditView->GetTextEditOutliner();

    OutlinerView *pOLV = mpEditView->GetTextEditOutlinerView();

    SdrTextObj *pNextLink = mpTextObj->GetNextLinkInChain();

    SdrTextObj *pPrevLink = mpTextObj->GetPrevLinkInChain();

    KeyFuncType eFunc = rKEvt.GetKeyCode().GetFunction();

    // We need to have this KeyFuncType

    if (eFunc !=  KeyFuncType::DONTKNOW && eFunc != KeyFuncType::DELETE)

    {

        rOutCursorEvt = CursorChainingEvent::NULL_EVENT;

        return;

    }

    sal_uInt16 nCode = rKEvt.GetKeyCode().GetCode();

    ESelection aCurSel = pOLV->GetSelection();

    ESelection aEndSelPrevBox(ESelection::AtEnd());

    sal_Int32 nLastPara = pOutl->GetParagraphCount()-1;

    OUString aLastParaText = pOutl->GetText(pOutl->GetParagraph(nLastPara));

    sal_Int32 nLastParaLen = aLastParaText.getLength();

    ESelection aEndSel(nLastPara, nLastParaLen);

    bool bAtEndOfTextContent = aCurSel == aEndSel;

    // Possibility: Are we "pushing" at the end of the object?

    if (nCode == KEY_RIGHT && bAtEndOfTextContent && pNextLink)

    {

        rOutCursorEvt = CursorChainingEvent::TO_NEXT_LINK;

        // Selection unchanged: we are at the beginning of the box

        rOutHandled = true; // Nothing more to do than move cursor

        return;

    }

    // Possibility: Are we "pushing" at the end of the object?

    if (eFunc == KeyFuncType::DELETE && bAtEndOfTextContent && pNextLink)

    {

        rOutCursorEvt = CursorChainingEvent::TO_NEXT_LINK;

        // Selection unchanged: we are at the beginning of the box

        rOutHandled = false; // We still need to delete the characters

        mbHandlingDel = true;

        return;

    }

    ESelection aStartSel(0, 0);

    bool bAtStartOfTextContent = aCurSel == aStartSel;

    // Possibility: Are we "pushing" at the start of the object?

    if (nCode == KEY_LEFT && bAtStartOfTextContent && pPrevLink)

    {

        rOutCursorEvt = CursorChainingEvent::TO_PREV_LINK;

        rOutSel = aEndSelPrevBox; // Set at end of selection

        rOutHandled = true; // Nothing more to do than move cursor

        return;

    }

    // Possibility: Are we "pushing" at the start of the object and deleting left?

    if (nCode == KEY_BACKSPACE && bAtStartOfTextContent && pPrevLink)

    {

        rOutCursorEvt = CursorChainingEvent::TO_PREV_LINK;

        rOutSel = aEndSelPrevBox; // Set at end of selection

        rOutHandled = false; // We need to delete characters after moving cursor

        return;

    }

    // If arrived here there is no event detected

    rOutCursorEvt = CursorChainingEvent::NULL_EVENT;

}

void TextChainCursorManager::HandleCursorEventAfterChaining(

                            const CursorChainingEvent aCurEvt,

                            const ESelection& aNewSel)

{

     // Special case for DELETE handling: we need to get back at the end of the prev box

    if (mbHandlingDel) {

        // reset flag

        mbHandlingDel = false;

        // Move to end of prev box

        SdrTextObj *pPrevLink = mpTextObj->GetPrevLinkInChain();

        impChangeEditingTextObj(pPrevLink, ESelection::AtEnd());

        return;

    }

    // Standard handling

    HandleCursorEvent(aCurEvt, aNewSel);

}

void TextChainCursorManager::HandleCursorEvent(

                            const CursorChainingEvent aCurEvt,

                            const ESelection& aNewSel)

{

    OutlinerView* pOLV = mpEditView->GetTextEditOutlinerView();

    SdrTextObj *pNextLink = mpTextObj->GetNextLinkInChain();

    SdrTextObj *pPrevLink = mpTextObj->GetPrevLinkInChain();

    switch ( aCurEvt ) {

            case CursorChainingEvent::UNCHANGED:

                // Set same selection as before the chaining (which is saved as PostChainingSel)

                // We need an explicit set because the Outliner is messed up

                //    after text transfer and otherwise it brings us at arbitrary positions.

                pOLV->SetSelection(aNewSel);

                break;

            case CursorChainingEvent::TO_NEXT_LINK:

                mpTextObj->GetTextChain()->SetSwitchingToNextBox(mpTextObj, true);

                impChangeEditingTextObj(pNextLink, aNewSel);

                break;

            case CursorChainingEvent::TO_PREV_LINK:

                impChangeEditingTextObj(pPrevLink, aNewSel);

                break;

            case CursorChainingEvent::NULL_EVENT:

                // Do nothing here

                break;

    }

}

void TextChainCursorManager::impChangeEditingTextObj(SdrTextObj *pTargetTextObj, ESelection aNewSel)

{

    assert(pTargetTextObj);

    mpEditView->SdrEndTextEdit();

    mpEditView->SdrBeginTextEdit(pTargetTextObj);

    // OutlinerView has changed, so we update the pointer

    OutlinerView *pOLV = mpEditView->GetTextEditOutlinerView();

    pOLV->SetSelection(aNewSel);

    // Update reference text obj

    mpTextObj = pTargetTextObj;

}

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