Added autoHide property to QTabBar

This property is used to automatically hide tab bar if it has only one
tab.

Originally-by: Denis Kovalskiy <denimnumber1@gmail.com>
Change-Id: I6967f760010fa55bad6a5986c29abe7ccf625cf8
Reviewed-by: David Faure <david.faure@kdab.com>

src/widgets/widgets/qtabbar.cpp

@@ -632,6 +632,14 @@ void QTabBarPrivate::layoutWidgets(int start)
     }
 }
 
+void QTabBarPrivate::autoHideTabs()
+{
+    Q_Q(QTabBar);
+
+    if (autoHide)
+        q->setVisible(q->count() > 1);
+}
+
 void QTabBarPrivate::_q_closeTab()
 {
     Q_Q(QTabBar);
@@ -861,6 +869,7 @@ int QTabBar::insertTab(int index, const QIcon& icon, const QString &text)
     }
 
     tabInserted(index);
+    d->autoHideTabs();
     return index;
 }
 
@@ -936,6 +945,7 @@ void QTabBar::removeTab(int index)
             setCurrentIndex(d->currentIndex - 1);
         }
         d->refresh();
+        d->autoHideTabs();
         tabRemoved(index);
     }
 }
@@ -2266,6 +2276,36 @@ void QTabBar::setDocumentMode(bool enabled)
     d->updateMacBorderMetrics();
 }
 
+/*!
+    \property QTabBar::autoHide
+    \brief If true, the tab bar is automatically hidden when it contains less
+    than 2 tabs.
+    \since 5.4
+
+    By default, this property is false.
+
+    \sa QWidget::visible
+*/
+
+bool QTabBar::autoHide() const
+{
+    Q_D(const QTabBar);
+    return d->autoHide;
+}
+
+void QTabBar::setAutoHide(bool hide)
+{
+    Q_D(QTabBar);
+    if (d->autoHide == hide)
+        return;
+
+    d->autoHide = hide;
+    if (hide)
+        d->autoHideTabs();
+    else
+        setVisible(true);
+}
+
 /*!
     Sets \a widget on the tab \a index.  The widget is placed
     on the left or right hand side depending upon the \a position.

src/widgets/widgets/qtabbar.h

@@ -70,6 +70,7 @@ class Q_WIDGETS_EXPORT QTabBar: public QWidget
     Q_PROPERTY(bool expanding READ expanding WRITE setExpanding)
     Q_PROPERTY(bool movable READ isMovable WRITE setMovable)
     Q_PROPERTY(bool documentMode READ documentMode WRITE setDocumentMode)
+    Q_PROPERTY(bool autoHide READ autoHide WRITE setAutoHide)
 
 public:
     explicit QTabBar(QWidget* parent=0);
@@ -166,6 +167,9 @@ public:
     bool documentMode() const;
     void setDocumentMode(bool set);
 
+    bool autoHide() const;
+    void setAutoHide(bool hide);
+
 public Q_SLOTS:
     void setCurrentIndex(int index);
 

src/widgets/widgets/qtabbar_p.h

@@ -77,7 +77,7 @@ public:
         :currentIndex(-1), pressedIndex(-1), shape(QTabBar::RoundedNorth), layoutDirty(false),
         drawBase(true), scrollOffset(0), elideModeSetByUser(false), useScrollButtonsSetByUser(false), expanding(true), closeButtonOnTabs(false),
         selectionBehaviorOnRemove(QTabBar::SelectRightTab), paintWithOffsets(true), movable(false),
-        dragInProgress(false), documentMode(false), movingTab(0)
+        dragInProgress(false), documentMode(false), autoHide(false), movingTab(0)
 #ifdef Q_WS_MAC
         , previousPressedIndex(-1)
 #endif
@@ -184,6 +184,7 @@ public:
     void updateMacBorderMetrics();
     bool isTabInMacUnifiedToolbarArea() const;
     void setupMovableTab();
+    void autoHideTabs();
 
     void makeVisible(int index);
     QSize iconSize;
@@ -201,6 +202,7 @@ public:
     bool movable;
     bool dragInProgress;
     bool documentMode;
+    bool autoHide;
 
     QWidget *movingTab;
 #ifdef Q_WS_MAC

src/widgets/widgets/qtabwidget.cpp

@@ -1350,6 +1350,29 @@ void QTabWidget::setDocumentMode(bool enabled)
     setUpLayout();
 }
 
+/*!
+    \property QTabWidget::tabBarAutoHide
+    \brief If true, the tab bar is automatically hidden when it contains less
+    than 2 tabs.
+    \since 5.4
+
+    By default, this property is false.
+
+    \sa QWidget::visible
+*/
+
+bool QTabWidget::tabBarAutoHide() const
+{
+    Q_D(const QTabWidget);
+    return d->tabs->autoHide();
+}
+
+void QTabWidget::setTabBarAutoHide(bool enabled)
+{
+    Q_D(QTabWidget);
+    return d->tabs->setAutoHide(enabled);
+}
+
 /*!
     Removes all the pages, but does not delete them. Calling this function
     is equivalent to calling removeTab() until the tab widget is empty.

src/widgets/widgets/qtabwidget.h

@@ -68,6 +68,7 @@ class Q_WIDGETS_EXPORT QTabWidget : public QWidget
     Q_PROPERTY(bool documentMode READ documentMode WRITE setDocumentMode)
     Q_PROPERTY(bool tabsClosable READ tabsClosable WRITE setTabsClosable)
     Q_PROPERTY(bool movable READ isMovable WRITE setMovable)
+    Q_PROPERTY(bool tabBarAutoHide READ tabBarAutoHide WRITE setTabBarAutoHide)
 
 public:
     explicit QTabWidget(QWidget *parent = 0);
@@ -140,6 +141,9 @@ public:
     bool documentMode() const;
     void setDocumentMode(bool set);
 
+    bool tabBarAutoHide() const;
+    void setTabBarAutoHide(bool enabled);
+
     void clear();
 
     QTabBar* tabBar() const;

tests/auto/widgets/widgets/qtabbar/tst_qtabbar.cpp

@@ -99,6 +99,7 @@ private slots:
     void taskQTBUG_10052_widgetLayoutWhenMoving();
 
     void tabBarClicked();
+    void autoHide();
 };
 
 // Testing get/set functions
@@ -701,5 +702,32 @@ void tst_QTabBar::tabBarClicked()
     }
 }
 
+void tst_QTabBar::autoHide()
+{
+    QTabBar tabBar;
+    QVERIFY(!tabBar.autoHide());
+    QVERIFY(!tabBar.isVisible());
+    tabBar.show();
+    QVERIFY(tabBar.isVisible());
+    tabBar.addTab("0");
+    QVERIFY(tabBar.isVisible());
+    tabBar.removeTab(0);
+    QVERIFY(tabBar.isVisible());
+
+    tabBar.setAutoHide(true);
+    QVERIFY(!tabBar.isVisible());
+    tabBar.addTab("0");
+    QVERIFY(!tabBar.isVisible());
+    tabBar.addTab("1");
+    QVERIFY(tabBar.isVisible());
+    tabBar.removeTab(0);
+    QVERIFY(!tabBar.isVisible());
+    tabBar.removeTab(0);
+    QVERIFY(!tabBar.isVisible());
+
+    tabBar.setAutoHide(false);
+    QVERIFY(tabBar.isVisible());
+}
+
 QTEST_MAIN(tst_QTabBar)
 #include "tst_qtabbar.moc"