Qt QTabWidget 改变tabBar位置 并改变文字方向

起因

    QTabWidget默认的tabBar在最上端。

改进

    但有时需要将tabBar放置在左侧，但是设置后效果如下…

最终

    有时候需要如下效果，则需要自定义style：

 附相应代码（具体边框可通过stylesheet进行设置）

 1 #include "mainwindow.h"
 2 #include "ui_mainwindow.h"
 3 
 4 #include <QPainter>
 5 #include <QProxyStyle>
 6 
 7 class CustomTabStyle : public QProxyStyle
 8 {
 9 public:
10     QSize sizeFromContents(ContentsType type, const QStyleOption *option,
11         const QSize &size, const QWidget *widget) const
12     {
13         QSize s = QProxyStyle::sizeFromContents(type, option, size, widget);
14         if (type == QStyle::CT_TabBarTab) {
15             s.transpose();
16             s.rwidth() = 90; // 设置每个tabBar中item的大小
17             s.rheight() = 44;
18         }
19         return s;
20     }
21 
22     void drawControl(ControlElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget) const
23     {
24         if (element == CE_TabBarTabLabel) {
25             if (const QStyleOptionTab *tab = qstyleoption_cast<const QStyleOptionTab *>(option)) {
26                 QRect allRect = tab->rect;
27 
28                 if (tab->state & QStyle::State_Selected) {
29                     painter->save();
30                     painter->setPen(0x89cfff);
31                     painter->setBrush(QBrush(0x89cfff));
32                     painter->drawRect(allRect.adjusted(6, 6, -6, -6));
33                     painter->restore();
34                 }
35                 QTextOption option;
36                 option.setAlignment(Qt::AlignCenter);
37                 if (tab->state & QStyle::State_Selected) {
38                     painter->setPen(0xf8fcff);
39                 }
40                 else {
41                     painter->setPen(0x5d5d5d);
42                 }
43 
44                 painter->drawText(allRect, tab->text, option);
45                 return;
46             }
47         }
48 
49         if (element == CE_TabBarTab) {
50             QProxyStyle::drawControl(element, option, painter, widget);
51         }
52     }
53 };
54 
55 MainWindow::MainWindow(QWidget *parent) :
56     QMainWindow(parent),
57     ui(new Ui::MainWindow)
58 {
59     ui->setupUi(this);
60     ui->tabWidget->setTabPosition(QTabWidget::West);
61     ui->tabWidget->tabBar()->setStyle(new CustomTabStyle);
62 
63 #if 0
64     ui->tabWidget->setStyleSheet("QTabWidget::pane{ \
65             border-left: 1px solid #eeeeee;\
66         }");
67 #endif
68 }
69 
70 MainWindow::~MainWindow()
71 {
72     delete ui;
73 }