Add QTreeView-derived variant of NavigatableTreeWidget

GnuPG-bug-id: 6102

src/CMakeLists.txt

@@ -133,6 +133,8 @@ target_sources(KF5Libkleo PRIVATE
    ui/filenamerequester.h
    ui/messagebox.cpp
    ui/messagebox.h
+   ui/navigatabletreeview.cpp
+   ui/navigatabletreeview.h
    ui/navigatabletreewidget.cpp
    ui/navigatabletreewidget.h
    ui/progressbar.cpp
@@ -292,6 +294,7 @@ ecm_generate_headers(libkleo_CamelCase_ui_HEADERS
   KeySelectionCombo
   KeySelectionDialog
   MessageBox
+  NavigatableTreeView
   NavigatableTreeWidget
   NewKeyApprovalDialog
   ProgressDialog

src/ui/navigatabletreeview.cpp

+/*
+    ui/navigatabletreeview.cpp
+
+    This file is part of libkleopatra
+    SPDX-FileCopyrightText: 2022 g10 Code GmbH
+    SPDX-FileContributor: Ingo Klöcker <dev@ingo-kloecker.de>
+
+    SPDX-License-Identifier: GPL-2.0-or-later
+*/
+
+#include <config-libkleo.h>
+
+#include "navigatabletreeview.h"
+
+using namespace Kleo;
+
+QModelIndex NavigatableTreeView::moveCursor(QAbstractItemView::CursorAction cursorAction, Qt::KeyboardModifiers modifiers)
+{
+    // make column by column keyboard navigation with Left/Right possible by switching
+    // the selection behavior to SelectItems before calling the parent class's moveCursor,
+    // because it ignores MoveLeft/MoveRight if the selection behavior is SelectRows;
+    // moreover, temporarily disable exanding of items to prevent expanding/collapsing
+    // on MoveLeft/MoveRight
+    if ((cursorAction != MoveLeft) && (cursorAction != MoveRight)) {
+        return QTreeView::moveCursor(cursorAction, modifiers);
+    }
+
+    const auto savedSelectionBehavior = selectionBehavior();
+    setSelectionBehavior(SelectItems);
+    const auto savedItemsExpandable = itemsExpandable();
+    setItemsExpandable(false);
+
+    const auto result = QTreeView::moveCursor(cursorAction, modifiers);
+
+    setItemsExpandable(savedItemsExpandable);
+    setSelectionBehavior(savedSelectionBehavior);
+
+    return result;
+}

src/ui/navigatabletreeview.h

+/*
+    ui/navigatabletreeview.h
+
+    This file is part of libkleopatra
+    SPDX-FileCopyrightText: 2022 g10 Code GmbH
+    SPDX-FileContributor: Ingo Klöcker <dev@ingo-kloecker.de>
+
+    SPDX-License-Identifier: GPL-2.0-or-later
+*/
+
+#pragma once
+
+#include "kleo_export.h"
+
+#include <QTreeView>
+
+namespace Kleo
+{
+
+/**
+ * A tree view that allows accessible column by column keyboard navigation.
+ *
+ * Column by column navigation is required to make a tree view accessible.
+ *
+ * The NavigatableTreeView allows column by column keyboard navigation even if
+ * the selection behavior is set to SelectRows and users can expand/collapse
+ * list items. To achieve this it deactivates the standard behavior of QTreeView
+ * to expand/collapse items if the left/right arrow keys are used.
+ *
+ * Additionally, you may want to disable parent-child navigation in tree views
+ * with left/right arrow keys because this also interferes with column by column
+ * navigation. You can do this by setting
+ * "QTreeView { arrow-keys-navigate-into-children: 0; }"
+ * as application style sheet.
+ *
+ * \sa NavigatableTreeWidget
+ */
+class KLEO_EXPORT NavigatableTreeView : public QTreeView
+{
+    Q_OBJECT
+public:
+    using QTreeView::QTreeView;
+
+protected:
+    QModelIndex moveCursor(QAbstractItemView::CursorAction cursorAction, Qt::KeyboardModifiers modifiers) override;
+};
+
+}

src/ui/navigatabletreewidget.h

@@ -18,11 +18,11 @@ namespace Kleo
 {
 
 /**
- * A tree view that allows extended keyboard navigation.
+ * A tree widget that allows accessible column by column keyboard navigation.
  *
- * The NavigatableTreeWidget allows column by column keyboard navigation even if
- * the selection behavior is set to SelectRows. Column by column navigation is
- * required to make a tree view accessible.
+ * This is the QTreeWidget-derived variant of NavigatableTreeView.
+ *
+ * \sa NavigatableTreeView
  */
 class KLEO_EXPORT NavigatableTreeWidget : public QTreeWidget
 {