Add Undo Framework QML API

This commit introduces an initial implementation of a QML API for the
Undo Framework.

The QML plugin for this API exports three new QML elements: UndoStack,
UndoCommand and UndoPropertyCommand. The API for both the first and
the second are very similar to the QUndoStack and QUndoCommand C++
APIs. The thrid use the declarative nature of the QML elements to
undo/redo based on the values of a group of properties specified by
the user.

This commit also adds an example in 'examples/undo/quickundo' to show
how this API could be used.

Other patchs are expected soon to improve this API and also add more
examples/docs.

Change-Id: I9d290f514b360c721116c3937bd0e03d5f0eacbb
Reviewed-by: Anselmo L. S. Melo <anselmo.melo@openbossa.org>

1 files changed, 134 insertions, 0 deletions

diff --git a/src/imports/undo/uiquickundocommands_p.h b/src/imports/undo/uiquickundocommands_p.h
new file mode 100644
index 0000000..f5d46c2
--- /dev/null
+++ b/src/imports/undo/uiquickundocommands_p.h
@@ -0,0 +1,134 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the UiHelpers playground module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef UIQUICKUNDOCOMMAND_H
+#define UIQUICKUNDOCOMMAND_H
+
+#include <UiHelpers/UiUndoStack>
+#include <QVariant>
+
+QT_USE_NAMESPACE_UIHELPERS;
+
+class UiQuickBaseUndoCommand : public QObject
+{
+    Q_OBJECT
+
+public:
+    UiQuickBaseUndoCommand(QObject *parent = 0);
+    ~UiQuickBaseUndoCommand();
+};
+
+// ------- //
+
+class UiQuickUndoCommand : public UiQuickBaseUndoCommand
+{
+    Q_OBJECT
+
+public:
+    UiQuickUndoCommand(QObject *parent = 0);
+    ~UiQuickUndoCommand();
+
+signals:
+    void undo(QObject *target);
+    void redo(QObject *target);
+    void commandDestroyed(QObject *target);
+};
+
+class UndoCommand : public UiUndoCommand
+{
+public:
+    UndoCommand(QObject* target, UiQuickUndoCommand *m_qmlObject);
+    ~UndoCommand();
+
+    void undo();
+    void redo();
+
+private:
+    QObject *m_target;
+    UiQuickUndoCommand *m_qmlObject;
+};
+
+// -----------------//
+
+class UiQuickUndoPropertyCommand : public UiQuickBaseUndoCommand
+{
+    Q_OBJECT
+
+    Q_PROPERTY(QVariantList properties READ properties WRITE setProperties NOTIFY propertiesChanged)
+
+public:
+    UiQuickUndoPropertyCommand(QObject *parent = 0);
+    ~UiQuickUndoPropertyCommand();
+
+    QVariantList properties() const;
+    void setProperties(const QVariantList& prop);
+
+signals:
+    void propertiesChanged();
+
+private:
+    QVariantList m_properties;
+};
+
+typedef QPair<QByteArray, QVariant> PropertyState;
+typedef QList<PropertyState> TargetState;
+
+class UndoPropertyCommand : public UiUndoCommand
+{
+
+public:
+    UndoPropertyCommand(QObject*, UiQuickUndoPropertyCommand*);
+    ~UndoPropertyCommand();
+
+    void undo();
+    void redo();
+
+private:
+    void saveState(TargetState& state);
+    void applyState(TargetState& state);
+
+    TargetState m_undoState;
+    TargetState m_redoState;
+    QObject *m_target;
+    UiQuickUndoPropertyCommand *m_qmlObject;
+};
+
+#endif