Move category tab widgets to separate widget and hide history category when there is no history

src/gui/CategoryListWidget.h

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2017 KeePassXC Team
+ *
+ * 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 or (at your option)
+ * version 3 of the License.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <QWidget>
+#include <QStyledItemDelegate>
+
+namespace Ui {
+    class CategoryListWidget;
+}
+
+class CategoryListWidget : public QWidget
+{
+    Q_OBJECT
+
+public:
+    CategoryListWidget(QWidget* parent = 0);
+    ~CategoryListWidget();
+
+    int currentCategory();
+    void setCurrentCategory(int index);
+    int addCategory(const QString& labelText, const QIcon& icon);
+    void setCategoryHidden(int index, bool hidden);
+    bool isCategoryHidden(int index);
+    void removeCategory(int index);
+
+signals:
+    void categoryChanged(int index);
+
+protected:
+    void showEvent(QShowEvent* event) override;
+    QSize sizeHint() const override;
+    QSize minimumSizeHint() const override;
+
+protected slots:
+    void updateCategoryScrollButtons();
+    void scrollCategoriesDown();
+    void scrollCategoriesUp();
+    void emitCategoryChanged(int index);
+
+private:
+    const QScopedPointer<Ui::CategoryListWidget> m_ui;
+
+    Q_DISABLE_COPY(CategoryListWidget)
+};
+
+
+/* =============================================================================================== */
+
+
+class CategoryListWidgetDelegate : public QStyledItemDelegate
+{
+    Q_OBJECT
+
+public:
+    explicit CategoryListWidgetDelegate(QWidget* parent = nullptr);
+
+protected:
+    void paint(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const override;
+    QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const override;
+
+private:
+    QSize m_size;
+
+    Q_DISABLE_COPY(CategoryListWidgetDelegate)
+};