QTabWidget和QTabBar的外观定制_qtabbar::tab 外圆弧

转自http://developer.qt.nokia.com/doc/qt-4.8/stylesheet-examples.html#customizing-qtabwidget-and-qtabbar

Customizing QTabWidget and QTabBar

For the screenshot above, we need a stylesheet as follows:

 QTabWidget::pane { /* The tab widget frame */
     border-top: 2px solid #C2C7CB;
 }
 
 QTabWidget::tab-bar {
     left: 5px; /* move to the right by 5px */
 }
 
 /* Style the tab using the tab sub-control. Note that
     it reads QTabBar _not_ QTabWidget */
 QTabBar::tab {
     background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
                                 stop: 0 #E1E1E1, stop: 0.4 #DDDDDD,
                                 stop: 0.5 #D8D8D8, stop: 1.0 #D3D3D3);
     border: 2px solid #C4C4C3;
     border-bottom-color: #C2C7CB; /* same as the pane color */
     border-top-left-radius: 4px;
     border-top-right-radius: 4px;
     min-width: 8ex;
     padding: 2px;
 }
 
 QTabBar::tab:selected, QTabBar::tab:hover {
     background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
                                 stop: 0 #fafafa, stop: 0.4 #f4f4f4,
                                 stop: 0.5 #e7e7e7, stop: 1.0 #fafafa);
 }
 
 QTabBar::tab:selected {
     border-color: #9B9B9B;
     border-bottom-color: #C2C7CB; /* same as pane color */
 }
 
 QTabBar::tab:!selected {
     margin-top: 2px; /* make non-selected tabs look smaller */
 }

Often we require the tabs to overlap to look like below:

For a tab widget that looks like above, we make use of negative margins. The resulting stylesheet looks like this:

 QTabWidget::pane { /* The tab widget frame */
     border-top: 2px solid #C2C7CB;
 }
 
 QTabWidget::tab-bar {
     left: 5px; /* move to the right by 5px */
 }
 
 /* Style the tab using the tab sub-control. Note that
     it reads QTabBar _not_ QTabWidget */
 QTabBar::tab {
     background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
                                 stop: 0 #E1E1E1, stop: 0.4 #DDDDDD,
                                 stop: 0.5 #D8D8D8, stop: 1.0 #D3D3D3);
     border: 2px solid #C4C4C3;
     border-bottom-color: #C2C7CB; /* same as the pane color */
     border-top-left-radius: 4px;
     border-top-right-radius: 4px;
     min-width: 8ex;
     padding: 2px;
 }
 
 QTabBar::tab:selected, QTabBar::tab:hover {
     background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
                                 stop: 0 #fafafa, stop: 0.4 #f4f4f4,
                                 stop: 0.5 #e7e7e7, stop: 1.0 #fafafa);
 }
 
 QTabBar::tab:selected {
     border-color: #9B9B9B;
     border-bottom-color: #C2C7CB; /* same as pane color */
 }
 
 QTabBar::tab:!selected {
     margin-top: 2px; /* make non-selected tabs look smaller */
 }
 
 /* make use of negative margins for overlapping tabs */
 QTabBar::tab:selected {
     /* expand/overlap to the left and right by 4px */
     margin-left: -4px;
     margin-right: -4px;
 }
 
 QTabBar::tab:first:selected {
     margin-left: 0; /* the first selected tab has nothing to overlap with on the left */
 }
 
 QTabBar::tab:last:selected {
     margin-right: 0; /* the last selected tab has nothing to overlap with on the right */
 }
 
 QTabBar::tab:only-one {
     margin: 0; /* if there is only one tab, we don't want overlapping margins */
 }

To move the tab bar to the center (as below), we require the following stylesheet:

 QTabWidget::pane { /* The tab widget frame */
     border-top: 2px solid #C2C7CB;
     position: absolute;
     top: -0.5em;
 }
 
 QTabWidget::tab-bar {
     alignment: center;
 }
 
 /* Style the tab using the tab sub-control. Note that
     it reads QTabBar _not_ QTabWidget */
 QTabBar::tab {
     background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
                                 stop: 0 #E1E1E1, stop: 0.4 #DDDDDD,
                                 stop: 0.5 #D8D8D8, stop: 1.0 #D3D3D3);
     border: 2px solid #C4C4C3;
     border-bottom-color: #C2C7CB; /* same as the pane color */
     border-top-left-radius: 4px;
     border-top-right-radius: 4px;
     min-width: 8ex;
     padding: 2px;
 }
 
 QTabBar::tab:selected, QTabBar::tab:hover {
     background: qlineargradient(x1: 0, y1: 0, x2: 0, y2: 1,
                                 stop: 0 #fafafa, stop: 0.4 #f4f4f4,
                                 stop: 0.5 #e7e7e7, stop: 1.0 #fafafa);
 }
 
 QTabBar::tab:selected {
     border-color: #9B9B9B;
     border-bottom-color: #C2C7CB; /* same as pane color */
 }

The tear indicator and the scroll buttons can be further customized as follows:

 QTabBar::tear {
     image: url(tear_indicator.png);
 }
 
 QTabBar::scroller { /* the width of the scroll buttons */
     width: 20px;
 }
 
 QTabBar QToolButton { /* the scroll buttons are tool buttons */
     border-image: url(scrollbutton.png) 2;
     border-width: 2px;
 }
 
 QTabBar QToolButton::right-arrow { /* the arrow mark in the tool buttons */
     image: url(rightarrow.png);
 }
 
 QTabBar QToolButton::left-arrow {
     image: url(leftarrow.png);
 }

Since Qt 4.6 the close button can be customized as follow:

 QTabBar::close-button {
     image: url(close.png)
     subcontrol-position: left;
 }
 QTabBar::close-button:hover {
     image: url(close-hover.png)
 }