[Qt] searchBox 搜索框实现

[Qt] searchBox 搜索框实现

也就是在lineEdit中加入button。在搜索框的右边会有个小小的搜索图标，输入内容之后，搜索的图标会变成叉叉。
类中的IconHelper见我的另一篇博文：http://www.cnblogs.com/mdgsf/p/4841272.html

//searchbox.h

#ifndef CSEARCHBOX_H
#define CSEARCHBOX_H

#include <QWidget>
#include <QLineEdit>
#include <QPushButton>

class CSearchBox : public QWidget
{
    Q_OBJECT
public:
    explicit CSearchBox(QWidget *parent = 0);
    ~CSearchBox();

signals:
    void sigSearch(QString str);
    void sigClear();

protected:
    bool eventFilter(QObject *obj, QEvent *event);

public slots:
    void slot_text_Edited(QString str);
    void slot_btn_clicked();

private:
    QLineEdit *m_pLineEdit;
    QPushButton *m_pBtn;
    enum EBtnStatus{ESEARCH, ECLOSE};
    EBtnStatus m_iCurBtnStatus;
};

#endif // CSEARCHBOX_H

//searchbox.cpp

#include "searchbox.h"
#include <QHBoxLayout>
#include <QKeyEvent>
#include "iconhelper.h"

CSearchBox::CSearchBox(QWidget *parent)
    : QWidget(parent)
{
    m_pLineEdit = new QLineEdit(this);
    m_pBtn = new QPushButton(m_pLineEdit);
    QSize size = QSize(20, m_pLineEdit->sizeHint().height());
    m_pBtn->setMinimumSize(size);
    m_pBtn->setMaximumSize(size);
    m_pBtn->setFocusPolicy(Qt::NoFocus);
    m_pBtn->setFlat(true);
    m_pBtn->setCursor(QCursor(Qt::PointingHandCursor));
    m_pBtn->setText(tr("Search"));
    m_iCurBtnStatus = ESEARCH;
    IconHelper::Instance()->SetIcon(m_pBtn, 0xf002);
    //0xf002 is search btn icon
    //0xf00d is close btn icon

    QHBoxLayout *buttonLayout = new QHBoxLayout();
    buttonLayout->setContentsMargins(0, 0, 0, 0);
    buttonLayout->addStretch();
    buttonLayout->addWidget(m_pBtn);
    m_pLineEdit->setLayout(buttonLayout);

    m_pLineEdit->setTextMargins(0, 1, size.width(), 1);
    m_pLineEdit->installEventFilter(this);

    QHBoxLayout *mainLayout = new QHBoxLayout();
    mainLayout->setContentsMargins(0, 0, 0, 0);
    mainLayout->addWidget(m_pLineEdit);
    this->setLayout(mainLayout);


    QString qss = QString("QPushButton {background: gray; color: white; border: 1 solid gray;min-width: 20px;}")
            + QString("QPushButton:hover {background: black; color: white; border: 1 solid black;}")
            + QString("QPushButton:pressed {background: white;color: black;}");
    this->setStyleSheet(qss);

    connect(m_pLineEdit, SIGNAL(textEdited(QString)),
            this, SLOT(slot_text_Edited(QString)) );
    connect(m_pBtn, SIGNAL(clicked()),
            this, SLOT(slot_btn_clicked()));
}

CSearchBox::~CSearchBox()
{
}

void
CSearchBox::slot_text_Edited(QString str)
{
    int iTextLen = str.size();
    if(iTextLen == 0)
    {
        m_iCurBtnStatus = ESEARCH;
        IconHelper::Instance()->SetIcon(m_pBtn, 0xf002);
        emit sigClear();
    }
    else
    {
        m_iCurBtnStatus = ECLOSE;
        IconHelper::Instance()->SetIcon(m_pBtn, 0xf00d);
    }
}

void
CSearchBox::slot_btn_clicked()
{
    if(m_iCurBtnStatus == ESEARCH)
    {
        //This is impossible
    }
    else
    {
        m_pLineEdit->clear();
        m_pLineEdit->setFocus();
        m_iCurBtnStatus = ESEARCH;
        IconHelper::Instance()->SetIcon(m_pBtn, 0xf002);
        emit sigClear();
    }
}

bool
CSearchBox::eventFilter(QObject *obj, QEvent *event)
{
    if(m_pLineEdit == qobject_cast<QLineEdit*>(obj))
    {
        QString str = m_pLineEdit->text().trimmed();
        if( (str.size() > 0) &&
            (event->type() == QEvent::KeyPress))
        {
            QKeyEvent *keyEvent = (QKeyEvent*)(event);
            if(keyEvent->key() == Qt::Key_Enter || keyEvent->key() == Qt::Key_Return)
            {
                m_pLineEdit->setFocus();
                emit sigSearch(str);
                return true;
            }
        }
    }

    return QObject::eventFilter(obj, event);
}

//调用方式

CSearchBox *pSearchBtn = new CSearchBox(ui->widget);
connect(pSearchBtn, SIGNAL(sigSearch(QString)),
        this, SLOT(slot_getSearchInfo(QString)) );

void
Widget::slot_getSearchInfo(QString str)
{
    QMessageBox::information(this, "test", str);
}