store history using sqlite, add suggestion with open

src/completionview.cpp

@@ -0,0 +1,66 @@
+#include "completionview.h"
+
+#include <QHeaderView>
+
+namespace {
+
+constexpr int kMaxVisibleRows = 12;
+
+} // namespace
+
+CompletionView::CompletionView(QWidget *parent)
+    : QTreeWidget(parent)
+{
+    setObjectName(QStringLiteral("completion"));
+    setFocusPolicy(Qt::NoFocus);
+    setColumnCount(2);
+    setHeaderHidden(true);
+    setRootIsDecorated(false);
+    setUniformRowHeights(true);
+    setFrameShape(QFrame::NoFrame);
+    setSelectionMode(QAbstractItemView::SingleSelection);
+    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    setTextElideMode(Qt::ElideRight);
+    header()->setStretchLastSection(false);
+    header()->setSectionResizeMode(QHeaderView::Stretch);
+    hide();
+}
+
+void CompletionView::setEntries(const QList<History::Entry> &entries)
+{
+    clear();
+    if (entries.isEmpty()) {
+        hide();
+        return;
+    }
+
+    QList<QTreeWidgetItem *> items;
+    items.reserve(entries.size());
+    for (const History::Entry &entry : entries) {
+        auto *item = new QTreeWidgetItem({entry.url, entry.title});
+        item->setToolTip(0, entry.url);
+        items.append(item);
+    }
+    addTopLevelItems(items);
+
+    const int rows = qMin(int(entries.size()), kMaxVisibleRows);
+    setFixedHeight(rows * sizeHintForRow(0) + 2 * frameWidth());
+    show();
+}
+
+QString CompletionView::cycle(int step)
+{
+    const int count = topLevelItemCount();
+    if (count == 0)
+        return {};
+
+    QTreeWidgetItem *current = currentItem();
+    int row = current && current->isSelected() ? indexOfTopLevelItem(current) + step
+                                               : (step > 0 ? 0 : count - 1);
+    row = ((row % count) + count) % count;
+
+    QTreeWidgetItem *item = topLevelItem(row);
+    setCurrentItem(item);
+    scrollToItem(item);
+    return item->text(0);
+}