greenshot/Greenshot/Memento/DeleteElementMemento.cs

74 lines
2.3 KiB
C#

/*
* Greenshot - a free and open source screenshot tool
* Copyright (C) 2007-2021 Thomas Braun, Jens Klingen, Robin Krom
*
* For more information see: http://getgreenshot.org/
* The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
*
* 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 1 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, see <http://www.gnu.org/licenses/>.
*/
using System;
using Greenshot.Drawing;
using GreenshotPlugin.Interfaces.Drawing;
namespace Greenshot.Memento {
/// <summary>
/// The DeleteElementMemento makes it possible to undo deleting an element
/// </summary>
public class DeleteElementMemento : IMemento {
private IDrawableContainer _drawableContainer;
private readonly Surface _surface;
public DeleteElementMemento(Surface surface, IDrawableContainer drawableContainer) {
_surface = surface;
_drawableContainer = drawableContainer;
}
public void Dispose() {
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if (!disposing) return;
if (_drawableContainer != null) {
_drawableContainer.Dispose();
_drawableContainer = null;
}
}
public bool Merge(IMemento otherMemento) {
return false;
}
public IMemento Restore() {
// Before
_drawableContainer.Invalidate();
var oldState = new AddElementMemento(_surface, _drawableContainer);
_surface.AddElement(_drawableContainer, false);
// The container has a selected flag which represents the state at the moment it was deleted.
if (_drawableContainer.Selected) {
_surface.SelectElement(_drawableContainer);
}
// After
_drawableContainer.Invalidate();
return oldState;
}
}
}