File indexing completed on 2024-07-14 03:54:02

0001 /*
0002     SPDX-FileCopyrightText: 2008 Fredrik Höglund <fredrik@kde.org>
0003 
0004     SPDX-License-Identifier: LGPL-2.0-or-later
0005 */
0006 
0007 #ifndef KABSTRACTVIEWADAPTER_H
0008 #define KABSTRACTVIEWADAPTER_H
0009 
0010 #include "kiofilewidgets_export.h"
0011 #include <QObject>
0012 
0013 class QAbstractItemModel;
0014 class QModelIndex;
0015 class QPalette;
0016 class QRect;
0017 class QSize;
0018 
0019 /*
0020  * TODO KF6 Q_PROPERTY(QSize iconSize READ iconSize WRITE setIconSize NOTIFY iconSizeChanged)
0021  * TODO KF6 virtual void setIconSize(const QSize &size);
0022  * TODO KF6 iconSizeChanged();
0023  *
0024  * TODO KF6:
0025  * KAbstractViewAdapter exists to allow KFilePreviewGenerator to be
0026  * reused with new kinds of views. Unfortunately it doesn't cover
0027  * all use cases that would be useful right now, in particular there
0028  * are no change notifications for the properties it has getters for.
0029  * This requires view implementations to e.g. call updateIcons() on
0030  * the generator when the icon size changes, which means updating two
0031  * entities (the generator and the adapter) instead of only one.
0032  * In KF6 we should make iconSize a Q_PROPERTY with a virtual setter
0033  * and a change notification signal, and make KFilePreviewGenerator
0034  * listen to that signal.
0035  * A related problem is that while the adapter is supposed to inter-
0036  * face a view to the generator, it is sometimes the generator that
0037  * is responsible for instantiating the adapter: KDirOperator in this
0038  * framework uses the KFilePreviewGenerator constructor that doesn't
0039  * take an adapter instance, which makes the generator instantiate a
0040  * KIO::DefaultViewAdapter internally, which it doesn't expose to the
0041  * outside. That means even when a setIconSize() is added,
0042  * KDirOperator won't be able to call it on the adapter. This mis-
0043  * design needs to be addressed as well so all change notifications
0044  * can run through the adapter, also for the DefaultViewAdapter
0045  * implementation (though for this specific example, perhaps Qt will
0046  * one day give us a NOTIFY for QAbstractItemView::iconSize that the
0047  * DefaultViewAdapter can use, obviating the need for KDirOperator
0048  * to do anything except call setIconSize on its QAbstractItemView).
0049  */
0050 
0051 /**
0052  * @class KAbstractViewAdapter kabstractviewadapter.h <KAbstractViewAdapter>
0053  *
0054  * Interface used by KFilePreviewGenerator to generate previews
0055  * for files. The interface allows KFilePreviewGenerator to be
0056  * independent from the view implementation.
0057  */
0058 class KIOFILEWIDGETS_EXPORT KAbstractViewAdapter : public QObject
0059 {
0060 public:
0061     enum Signal { ScrollBarValueChanged, IconSizeChanged };
0062 
0063     KAbstractViewAdapter(QObject *parent)
0064         : QObject(parent)
0065     {
0066     }
0067     ~KAbstractViewAdapter() override
0068     {
0069     }
0070     virtual QAbstractItemModel *model() const = 0;
0071     virtual QSize iconSize() const = 0;
0072     virtual QPalette palette() const = 0;
0073     virtual QRect visibleArea() const = 0;
0074     virtual QRect visualRect(const QModelIndex &index) const = 0;
0075 
0076     // TODO KF6 make this connect work with a PointerToMemberFunction/Functor
0077     virtual void connect(Signal signal, QObject *receiver, const char *slot) = 0;
0078 };
0079 
0080 #endif