Qt: extract ListTabWidget from SettingsWindow

Source/Core/DolphinQt2/QtUtils/ListTabWidget.cpp

@@ -0,0 +1,72 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include "DolphinQt2/QtUtils/ListTabWidget.h"
+
+#include <QHBoxLayout>
+#include <QListWidget>
+#include <QScrollBar>
+#include <QStackedWidget>
+
+class OverriddenListWidget : public QListWidget
+{
+public:
+  // We want this widget to have a fixed width that fits all items, unlike a normal QListWidget
+  // which adds scrollbars and expands/contracts.
+  OverriddenListWidget() { setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Preferred); }
+  QSize sizeHint() const override
+  {
+    int width = sizeHintForColumn(0) + verticalScrollBar()->sizeHint().width() + 2 * frameWidth();
+    int height = QListWidget::sizeHint().height();
+    return {width, height};
+  }
+};
+
+ListTabWidget::ListTabWidget()
+{
+  QHBoxLayout* layout = new QHBoxLayout();
+  layout->setContentsMargins(0, 0, 0, 0);
+  setLayout(layout);
+
+  m_labels = new OverriddenListWidget();
+  layout->addWidget(m_labels);
+  m_labels->setIconSize(QSize(32, 32));
+  m_labels->setMovement(QListView::Static);
+  m_labels->setSpacing(0);
+
+  m_display = new QStackedWidget();
+  layout->addWidget(m_display);
+
+  connect(m_labels, &QListWidget::currentItemChanged, this,
+          [=](QListWidgetItem* current, QListWidgetItem* previous) {
+            if (!current)
+              current = previous;
+            m_display->setCurrentIndex(m_labels->row(current));
+          });
+}
+
+int ListTabWidget::addTab(QWidget* page, const QString& label)
+{
+  QListWidgetItem* button = new QListWidgetItem();
+  button->setText(label);
+  button->setTextAlignment(Qt::AlignVCenter);
+  button->setFlags(Qt::ItemIsSelectable | Qt::ItemIsEnabled);
+
+  m_labels->addItem(button);
+  if (!m_labels->currentItem())
+    m_labels->setCurrentItem(button);
+
+  return m_display->addWidget(page);
+}
+
+void ListTabWidget::setTabIcon(int index, const QIcon& icon)
+{
+  if (auto* label = m_labels->item(index))
+    label->setIcon(icon);
+}
+
+void ListTabWidget::setCurrentIndex(int index)
+{
+  m_labels->setCurrentRow(index);
+}

Source/Core/DolphinQt2/QtUtils/ListTabWidget.h

@@ -0,0 +1,23 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <QWidget>
+
+class QListWidget;
+class QStackedWidget;
+
+class ListTabWidget : public QWidget
+{
+public:
+  ListTabWidget();
+  int addTab(QWidget* page, const QString& label);
+  void setTabIcon(int index, const QIcon& icon);
+  void setCurrentIndex(int index);
+
+private:
+  QListWidget* m_labels;
+  QStackedWidget* m_display;
+};