qt: introduce SelectableListModel

Add a QAbstractListModel subclass which maintain a selection state. This
will avoid to manage selection in an additional layer (DelegateModel) in
Qml.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/qt/Makefile.am

@@ -93,6 +93,8 @@ libqt_plugin_la_SOURCES = \
 	gui/qt/components/player_controller.cpp gui/qt/components/player_controller.hpp gui/qt/components/player_controller_p.hpp \
 	gui/qt/components/preferences_widgets.cpp \
 	gui/qt/components/preferences_widgets.hpp \
+	gui/qt/components/selectable_list_model.hpp \
+	gui/qt/components/selectable_list_model.cpp \
 	gui/qt/components/complete_preferences.cpp \
 	gui/qt/components/complete_preferences.hpp \
 	gui/qt/components/simple_preferences.cpp \
@@ -260,6 +262,7 @@ nodist_libqt_plugin_la_SOURCES = \
 	gui/qt/components/controller_widget.moc.cpp \
 	gui/qt/components/custom_menus.moc.cpp \
 	gui/qt/components/recent_media_model.moc.cpp \
+	gui/qt/components/selectable_list_model.moc.cpp \
 	gui/qt/components/settings.moc.cpp \
 	gui/qt/components/voutwindow/videosurface.moc.cpp \
 	gui/qt/components/voutwindow/qvoutwindow.moc.cpp \

modules/gui/qt/components/selectable_list_model.cpp

+/*****************************************************************************
+ * Copyright (C) 2019 VLC authors and VideoLAN
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "selectable_list_model.hpp"
+
+namespace vlc {
+
+void SelectableListModel::setSelected(int row, bool selected)
+{
+    setRowSelected(row, selected);
+
+    QModelIndex modelIndex = index(row);
+    emit dataChanged(modelIndex, modelIndex, { getSelectedRole() });
+}
+
+bool SelectableListModel::isSelected(int row) const
+{
+    return isRowSelected(row);
+}
+
+void SelectableListModel::toggleSelected(int row)
+{
+    setRowSelected(row, !isRowSelected(row));
+
+    QModelIndex modelIndex = index(row);
+    emit dataChanged(modelIndex, modelIndex, { getSelectedRole() });
+}
+
+void SelectableListModel::setSelection(const QList<int> &sortedIndexes)
+{
+    int itemsCount = rowCount();
+
+    if (!itemsCount)
+        return;
+
+    int indexesCount = sortedIndexes.size();
+    int p = 0; /* points to the current index in sortedIndexes */
+    for (int i = 0; i < itemsCount; ++i)
+    {
+        /* the indexes are sorted, so only check the next one */
+        if (p < indexesCount && i == sortedIndexes[p])
+        {
+            setRowSelected(i, true);
+            ++p;
+        }
+        else
+        {
+            setRowSelected(i, false);
+        }
+    }
+
+    QModelIndex first = index(0);
+    QModelIndex last = index(itemsCount - 1);
+    emit dataChanged(first, last, { getSelectedRole() });
+}
+
+QList<int> SelectableListModel::getSelection() const
+{
+    int itemsCount = rowCount();
+
+    QList<int> indexes;
+    for (int i = 0; i < itemsCount; ++i)
+    {
+        if (isRowSelected(i))
+            indexes.push_back(i);
+    }
+    return indexes;
+}
+
+void SelectableListModel::setRangeSelected(int start, int count, bool selected)
+{
+    for (int i = start; i < start + count; ++i)
+        setRowSelected(i, selected);
+
+    QModelIndex first = index(start);
+    QModelIndex last = index(start + count - 1);
+    emit dataChanged(first, last, { getSelectedRole() });
+}
+
+void SelectableListModel::selectAll()
+{
+    int count = rowCount();
+
+    if (!count)
+        return;
+
+    setRangeSelected(0, count, true);
+}
+
+void SelectableListModel::deselectAll()
+{
+    int count = rowCount();
+
+    if (!count)
+        return;
+
+    setRangeSelected(0, count, false);
+}
+
+} // namespace vlc

modules/gui/qt/components/selectable_list_model.hpp

+/*****************************************************************************
+ * Copyright (C) 2019 VLC authors and VideoLAN
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifndef VLC_QT_SELECTABLE_LIST_MODEL_HPP_
+#define VLC_QT_SELECTABLE_LIST_MODEL_HPP_
+
+#include <QAbstractListModel>
+
+namespace vlc {
+
+class SelectableListModel : public QAbstractListModel
+{
+    Q_OBJECT
+public:
+    SelectableListModel(QObject *parent = nullptr) :
+        QAbstractListModel(parent) {}
+
+    Q_INVOKABLE bool isSelected(int index) const;
+    Q_INVOKABLE void setSelected(int index, bool selected);
+    Q_INVOKABLE void toggleSelected(int index);
+    Q_INVOKABLE void setSelection(const QList<int> &sortedIndexes);
+    Q_INVOKABLE QList<int> getSelection() const;
+    Q_INVOKABLE void setRangeSelected(int first, int count, bool selected);
+    Q_INVOKABLE void selectAll();
+    Q_INVOKABLE void deselectAll();
+
+protected:
+    virtual bool isRowSelected(int row) const = 0;
+    virtual void setRowSelected(int row, bool selected) = 0;
+
+    /* return the role to notify when selection changes */
+    virtual int getSelectedRole() const = 0;
+};
+
+} // namespace vlc
+
+#endif