this patch removes the centering and makes the tabbar to take up all the

width when it's not like a tabwidget and there is some
sizepolicy/preferred sizes setting fixes that makes it behave better in
a panel (especially vertical ones)

svn path=/trunk/KDE/kdebase/workspace/libs/plasma/; revision=854953

private/nativetabbar.cpp

@@ -142,6 +142,7 @@ QSize NativeTabBar::tabSizeHint(int index) const
     QSize hint = tabSize(index);
     int minwidth = 0;
     int minheight = 0;
+    int maxwidth = 0;
 
     Shape s = shape();
     switch (s) {
@@ -158,6 +159,7 @@ QSize NativeTabBar::tabSizeHint(int index) const
                 if (minwidth < width()) {
                     hint.rwidth() += (width() - minwidth) / count();
                 }
+                hint.rheight() += d->top + d->bottom;
             }
             break;
         case RoundedWest:
@@ -167,14 +169,17 @@ QSize NativeTabBar::tabSizeHint(int index) const
             if (count() > 0) {
                 for (int i = count() - 1; i >= 0; i--) {
                     minheight += tabSize(i).height();
+                    if (tabSize(i).width() > maxwidth) {
+                        maxwidth = tabSize(i).width();
+                    }
                 }
                 minheight += d->top + d->bottom;
 
                 if (minheight < height()) {
                     hint.rheight() += (height() - minheight) / count();
                 }
+                hint.rwidth() = maxwidth + d->left + d->right;
             }
-            hint.rwidth() = qMax( hint.width(), width() );
             break;
     }
     return hint;
@@ -183,17 +188,21 @@ QSize NativeTabBar::tabSizeHint(int index) const
 //FIXME: this shouldn't be necessary but it seems to return wring numbers the base implementation?
 QSize NativeTabBar::sizeHint() const
 {
-    if (count() < 1) {
+    int width = 0;
-        return QTabBar::sizeHint();
+    int height = 0;
-    }
-
-    int width = tabRect(0).width();
-    int height = tabRect(0).height();
 
     if (isVertical()) {
-        height *= count();
+        for (int i = count() - 1; i >= 0; i--) {
+             height += tabRect(i).height();
+        }
+
+        width = tabRect(0).width();
     } else {
-        width *= count();
+        for (int i = count() - 1; i >= 0; i--) {
+             width += tabRect(i).width();
+        }
+
+        height = tabRect(0).height();
     }
     return QSize(width+d->left+d->right, height+d->top+d->bottom);
 }

widgets/tabbar.cpp

@@ -53,11 +53,15 @@ public:
     {
     }
 
+    void updateTabWidgetMode();
     void slidingCompleted(QGraphicsItem *item);
     void shapeChanged(const QTabBar::Shape shape);
 
     TabBar *q;
     NativeTabBar *tabBar;
+    QGraphicsProxyWidget *tabProxy;
+    QGraphicsWidget *leftSpacer;
+    QGraphicsWidget *rightSpacer;
     QList<QGraphicsWidget *> pages;
     QGraphicsLinearLayout *mainLayout;
     QGraphicsLinearLayout *tabBarLayout;
@@ -70,6 +74,31 @@ public:
 };
 
 
+
+void TabBarPrivate::updateTabWidgetMode()
+{
+    bool tabWidget = false;
+
+    foreach (QGraphicsWidget *page, pages) {
+        if (page->preferredSize() != QSize(0, 0)) {
+            tabWidget = true;
+            break;
+        }
+    }
+
+    if (tabWidget && tabBarLayout->count() < 3) {
+        tabBarLayout->insertItem(0, leftSpacer);
+        tabBarLayout->insertItem(2, rightSpacer);
+        leftSpacer->show();
+        rightSpacer->show();
+    } else if (!tabWidget && tabBarLayout->count() >= 3) {
+        tabBarLayout->removeItem(leftSpacer);
+        tabBarLayout->removeItem(rightSpacer);
+        leftSpacer->hide();
+        rightSpacer->hide();
+    }
+}
+
 void TabBarPrivate::slidingCompleted(QGraphicsItem *item)
 {
     if (item == oldPage || item == newPage) {
@@ -94,9 +123,11 @@ void TabBarPrivate::shapeChanged(const QTabBar::Shape shape)
 
     case QTabBar::RoundedEast:
     case QTabBar::TriangularEast:
+        tabBarLayout->setOrientation(Qt::Vertical);
         mainLayout->setOrientation(Qt::Horizontal);
         mainLayout->itemAt(0)->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Preferred);
-        mainLayout->itemAt(1)->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Expanding);
+        mainLayout->itemAt(1)->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+        tabProxy->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Preferred);
         break;
 
     case QTabBar::RoundedSouth:
@@ -105,10 +136,13 @@ void TabBarPrivate::shapeChanged(const QTabBar::Shape shape)
     case QTabBar::RoundedNorth:
     case QTabBar::TriangularNorth:
     default:
+        tabBarLayout->setOrientation(Qt::Horizontal);
         mainLayout->setOrientation(Qt::Vertical);
-        mainLayout->itemAt(0)->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
+        mainLayout->itemAt(0)->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Preferred);
-        mainLayout->itemAt(1)->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
+        mainLayout->itemAt(1)->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+        tabProxy->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
     }
+    tabProxy->setPreferredSize(tabBar->sizeHint());
 }
 
 
@@ -125,14 +159,20 @@ TabBar::TabBar(QGraphicsWidget *parent)
 
     d->mainLayout->addItem(d->tabBarLayout);
 
-    QGraphicsProxyWidget *tabProxy = new QGraphicsProxyWidget(this);
+    d->tabProxy = new QGraphicsProxyWidget(this);
-    tabProxy->setWidget(d->tabBar);
+    d->tabProxy->setWidget(d->tabBar);
-    tabProxy->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
+    d->tabProxy->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
 
-    //tabBar are centered, so a stretch at begin one at the end
+    //tabBar is centered, so a stretch at begin one at the end
-    d->tabBarLayout->addStretch();
+    //FIXME: doesn't seem to be possible to remove stretches from a layout
-    d->tabBarLayout->addItem(tabProxy);
+    d->leftSpacer = new QGraphicsWidget(this);
-    d->tabBarLayout->addStretch();
+    d->rightSpacer = new QGraphicsWidget(this);
+    d->leftSpacer->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+    d->rightSpacer->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+    d->tabBarLayout->addItem(d->leftSpacer);
+    d->tabBarLayout->addItem(d->tabProxy);
+    d->tabBarLayout->addItem(d->rightSpacer);
+    //d->tabBarLayout->setStretchFactor(d->tabProxy, 2);
 
     connect(d->tabBar, SIGNAL(currentChanged(int)), this, SLOT(setCurrentIndex(int)));
     connect(d->tabBar, SIGNAL(shapeChanged(QTabBar::Shape)), this, SLOT(shapeChanged(QTabBar::Shape)));
@@ -168,7 +208,13 @@ int TabBar::insertTab(int index, const QIcon &icon, const QString &label, QGraph
         page->setEnabled(false);
     }
 
-    return d->tabBar->insertTab(index, icon, label);
+    d->tabProxy->setPreferredSize(d->tabBar->sizeHint());
+    d->updateTabWidgetMode();
+
+    int actualIndex = d->tabBar->insertTab(index, icon, label);
+    d->tabProxy->setPreferredSize(d->tabBar->sizeHint());
+    d->updateTabWidgetMode();
+    return actualIndex;
 }
 
 int TabBar::insertTab(int index, const QString &label, QGraphicsLayoutItem *content)
@@ -277,6 +323,9 @@ void TabBar::removeTab(int index)
 
     scene()->removeItem(page);
     page->deleteLater();
+
+    d->updateTabWidgetMode();
+    d->tabProxy->setPreferredSize(d->tabBar->sizeHint());
 }
 
 void TabBar::setTabText(int index, const QString &label)