kde-extraapps/kolourpaint/commands/tools/selection/text/kpToolTextGiveContentCommand.cpp

/*
   Copyright (c) 2003-2007 Clarence Dang <dang@kde.org>
   All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   1. Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
   2. Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.

   THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


#define DEBUG_KP_TOOL_SELECTION 0


#include <kpToolTextGiveContentCommand.h>

#include <kdebug.h>
#include <klocale.h>

#include <kpCommandEnvironment.h>
#include <kpDocument.h>
#include <kpTextSelection.h>
#include <kpViewManager.h>


kpToolTextGiveContentCommand::kpToolTextGiveContentCommand (
        const kpTextSelection &originalSelBorder,
        const QString &name,
        kpCommandEnvironment *environ)
    : kpAbstractSelectionContentCommand (originalSelBorder, name, environ)
{
#if DEBUG_KP_TOOL_SELECTION && 1
    kDebug () << "kpToolTextGiveContentCommand::<ctor>() environ="
               << environ
               << endl;
#endif
}

kpToolTextGiveContentCommand::~kpToolTextGiveContentCommand ()
{
}


// public virtual [base kpCommand]
void kpToolTextGiveContentCommand::execute ()
{
#if DEBUG_KP_TOOL_SELECTION && 1
    kDebug () << "kpToolTextGiveContentCommand::execute()";
#endif

    kpDocument *doc = document ();
    Q_ASSERT (doc);

    kpViewManager *vm = viewManager ();
    Q_ASSERT (vm);

    // See API Doc for kpViewManager::textCursorRow() & textCursorCol().
    Q_ASSERT (vm->textCursorRow () == 0 && vm->textCursorCol () == 0);

    vm->setQueueUpdates ();
    {
        //
        // Recreate border
        //

        // The previously executed command is required to have been a
        // kpToolSelectionCreateCommand, which must have been given a text
        // selection with no content.
        //
        // However, there is a tricky case.  Suppose we are called for the first
        // time, where the above precondition holds.  We would add content
        // to the selection as expected.  But the user then undoes (CTRL+Z) the
        // operation, calling unexecute().  There is now no content again.
        // Since selection is only a border, the user can freely deselect it
        // and/or select another region without changing the command history
        // or document modified state.  Therefore, if they now call us again
        // by redoing (CTRL+Shift+Z), there is potentially no selection at all
        // or it is at an arbitrary location.
        //
        // This assertion covers all 3 possibilities:
        //
        // 1. First call: text selection with no content
        // 2. Later calls:
        //    a) no text selection (due to deselection)
        //    b) text selection with no content, at an arbitrary location
        Q_ASSERT (!textSelection () || !textSelection ()->hasContent ());

        const kpTextSelection *originalTextSel =
            static_cast <const kpTextSelection *> (originalSelection ());
        if (originalTextSel->textStyle () != environ ()->textStyle ())
            environ ()->setTextStyle (originalTextSel->textStyle ());

        doc->setSelection (*originalSelection ());


        //
        // Add Content
        //

        QList <QString> listOfOneEmptyString;
        listOfOneEmptyString.append (QString ());
        textSelection ()->setTextLines (listOfOneEmptyString);
    }
    vm->restoreQueueUpdates ();

    // This should not have changed from the start of the method.
    Q_ASSERT (vm->textCursorRow () == 0 && vm->textCursorCol () == 0);
}

// public virtual [base kpCommand]
void kpToolTextGiveContentCommand::unexecute ()
{
#if DEBUG_KP_TOOL_SELECTION && 1
    kDebug () << "kpToolTextGiveContentCommand::unexecute()";
#endif

    kpDocument *doc = document ();
    Q_ASSERT (doc);
    // Must have selection text content.
    Q_ASSERT (doc->textSelection () && doc->textSelection ()->hasContent ());

    kpViewManager *vm = viewManager ();
    Q_ASSERT (vm);
    // All the commands after us have been unexecuted, so we must be back
    // to the state we were after our execute().
    Q_ASSERT (vm->textCursorRow () == 0 && vm->textCursorCol () == 0);

    // We can have faith that this is the state of the selection after
    // execute(), rather than after the user tried to throw us off by
    // simply selecting another region as to do that, a destroy command
    // must have been used.
    doc->textSelection ()->deleteContent ();

    // This should not have changed from the start of the method.
    Q_ASSERT (vm->textCursorRow () == 0 && vm->textCursorCol () == 0);
}