Qt放Element网页滑动菜单栏

基于QTabWidget实现菜单

tabwidget.h

#ifndef TAB_WIDGET_H
#define TAB_WIDGET_H#include <QTabWidget>
#include <QVariantAnimation>
#include "customcomponent_global.h"class TabBarAnimation;class TabWidget : public QTabWidget
{Q_OBJECTpublic:TabWidget (QWidget *parent = 0);~TabWidget ();void setAnimationCurrentValue(int value);protected:void paintEvent(QPaintEvent *);bool eventFilter(QObject *o, QEvent *e);private:void startAnimation(int beginX, int endX, int duration);private:TabBarAnimation *m_animation;int m_animationX;
};#endif

tabwidget.cpp

#include "tabwidget.h"
#include <QStyleOptionTabWidgetFrame>
#include <QStylePainter>
#include <QMouseEvent>const int AnimateBarWidth = 64;
const int AnimateBarHeight = 2;
const int AnimateBarXOffset = 30;const int LogoWidth = 140;
const int LogoHeight = 20;class TabBarAnimation : public QVariantAnimation
{
public:TabBarAnimation(InoTabWidget *t) :tabs(t){setEasingCurve(QEasingCurve::InOutQuad);}void updateCurrentValue(const QVariant &current) Q_DECL_OVERRIDE;private:InoTabWidget *tabs;
};void TabBarAnimation::updateCurrentValue(const QVariant &current)
{if (tabs) {tabs->setAnimationCurrentValue(current.toInt());}
}TabWidget::TabWidget(QWidget *parent) :QTabWidget(parent),m_animation(nullptr),m_animationX(-1)
{tabBar()->installEventFilter(this);tabBar()->setFixedHeight(40);
}TabWidget::~TabWidget()
{if (m_animation) {delete m_animation;m_animation = nullptr;}
}bool TabWidget::eventFilter(QObject *obj, QEvent *event)
{if (obj == tabBar() && event->type() == QEvent::MouseButtonPress) {QMouseEvent *pMouseEvent = (QMouseEvent *)event;if (pMouseEvent->button() == Qt::LeftButton) {const QPoint pos = pMouseEvent->pos();int index = tabBar()->tabAt(pos);if (index >= 0) {int curIndex = tabBar()->currentIndex();if (index != curIndex) {const QPoint tabBarPos = tabBar()->mapToGlobal(tabBar()->rect().topLeft());startAnimation(tabBarPos.x() + tabBar()->tabRect(curIndex).x() + tabBar()->tabRect(curIndex).width() / 2 - AnimateBarXOffset,tabBarPos.x() + tabBar()->tabRect(index).x() + tabBar()->tabRect(index).width() / 2 - AnimateBarXOffset, 250);}}}}return false;
}void TabWidget::startAnimation(int beginX, int endX, int duration)
{if (!m_animation) {m_animation = new TabBarAnimation(this);}m_animation->setStartValue(beginX);m_animation->setEndValue(endX);m_animation->setDuration(duration);m_animation->start();
}void TabWidget::setAnimationCurrentValue(int value)
{m_animationX = value;update();
}// 绘制背景下划线和当前Index的下划线
void TabWidget::paintEvent(QPaintEvent *event)
{Q_UNUSED(event);int index = tabBar()->currentIndex();QRect rect = tabBar()->tabRect(index);const QPoint tabBarPos = tabBar()->mapToGlobal(tabBar()->rect().topLeft());QStyleOptionTabWidgetFrame option;initStyleOption(&option);option.lineWidth = 0;QStylePainter p(this);option.rect = style()->subElementRect(QStyle::SE_TabWidgetTabPane, &option, this);p.drawPrimitive(QStyle::PE_FrameTabWidget, option);p.fillRect(QRect(option.rect.x(), rect.y(), option.rect.width(),rect.y() + rect.height() + AnimateBarHeight * 2),QColor(41, 90, 176));int x = (m_animation && m_animation->state() == QAbstractAnimation::Running) ?m_animationX :(tabBarPos.x() + rect.x() + rect.width() / 2 - AnimateBarXOffset);p.fillRect(QRect(x, rect.y() + rect.height(),AnimateBarWidth, AnimateBarHeight),QColor(255, 255, 255));
}