MultiSelectComboBox.cpp

#include "MultiSelectComboBox.h"
#include <QLineEdit>
#include <QCheckBox>
#include <QEvent>

namespace {
    const int scSearchBarIndex = 0;
}

MultiSelectComboBox::MultiSelectComboBox(QWidget* aParent) :
    QComboBox(aParent),
    mListWidget(new QListWidget(this)),
    mLineEdit(new QLineEdit(this)),
    mSearchBar(new QLineEdit(this))
{
    QListWidgetItem* curItem = new QListWidgetItem(mListWidget);
    mSearchBar->setPlaceholderText("Search..");
    mSearchBar->setClearButtonEnabled(true);
    mListWidget->addItem(curItem);
    mListWidget->setItemWidget(curItem, mSearchBar);

    mLineEdit->setReadOnly(true);
    mLineEdit->installEventFilter(this);

    setModel(mListWidget->model());
    setView(mListWidget);
    setLineEdit(mLineEdit);

    connect(mSearchBar, &QLineEdit::textChanged, this, &MultiSelectComboBox::onSearch);
    connect(this, static_cast<void (QComboBox::*)(int)>(&QComboBox::activated), this, &MultiSelectComboBox::itemClicked);
}

void MultiSelectComboBox::hidePopup()
{
    int width = this->width();
    int height = mListWidget->height();
    int x = QCursor::pos().x() - mapToGlobal(geometry().topLeft()).x() + geometry().x();
    int y = QCursor::pos().y() - mapToGlobal(geometry().topLeft()).y() + geometry().y();
    if (x >= 0 && x <= width && y >= this->height() && y <= height + this->height())
    {
        // Item was clicked, do not hide popup
    }
    else
    {
        QComboBox::hidePopup();
    }
}

void MultiSelectComboBox::stateChanged(int aState)
{
    Q_UNUSED(aState);
    QString selectedData("");
    int count = mListWidget->count();

    for (int i = 1; i < count; ++i)
    {
        QWidget *widget = mListWidget->itemWidget(mListWidget->item(i));
        QCheckBox *checkBox = static_cast<QCheckBox *>(widget);

        if (checkBox->isChecked())
        {
            selectedData.append(checkBox->text()).append(";");
        }
    }
    if (selectedData.endsWith(";"))
    {
        selectedData.remove(selectedData.count() - 1, 1);
    }
    if (!selectedData.isEmpty())
    {
        mLineEdit->setText(selectedData);
    }
    else
    {
        mLineEdit->clear();
    }

    mLineEdit->setToolTip(selectedData);
    emit selectionChanged();
}

void MultiSelectComboBox::addItem(const QString& aText, const QVariant& aUserData)
{
    Q_UNUSED(aUserData);
    QListWidgetItem* listWidgetItem = new QListWidgetItem(mListWidget);
    QCheckBox* checkBox = new QCheckBox(this);
    checkBox->setText(aText);
    mListWidget->addItem(listWidgetItem);
    mListWidget->setItemWidget(listWidgetItem, checkBox);
    connect(checkBox, &QCheckBox::stateChanged, this, &MultiSelectComboBox::stateChanged);
}

QStringList MultiSelectComboBox::currentText()
{
    QStringList emptyStringList;
    if(!mLineEdit->text().isEmpty())
    {
        emptyStringList = mLineEdit->text().split(';');
    }
    return emptyStringList;
}

void MultiSelectComboBox::addItems(const QStringList& aTexts)
{
    for(const auto& string : aTexts)
    {
        addItem(string);
    }
}

int MultiSelectComboBox::count() const
{
    int count = mListWidget->count() - 1;// Do not count the search bar
    if(count < 0)
    {
        count = 0;
    }
    return count;
}

void MultiSelectComboBox::onSearch(const QString& aSearchString)
{
    for(int i = 1; i < mListWidget->count(); i++)
    {
        QCheckBox* checkBox = static_cast<QCheckBox*>(mListWidget->itemWidget(mListWidget->item(i)));
        if(checkBox->text().contains(aSearchString, Qt::CaseInsensitive))
        {
            mListWidget->item(i)->setHidden(false);
        }
        else
        {
            mListWidget->item(i)->setHidden(true);
        }
    }
}


void MultiSelectComboBox::itemClicked(int aIndex)
{
    if(aIndex != scSearchBarIndex)// 0 means the search bar
    {
        QWidget* widget = mListWidget->itemWidget(mListWidget->item(aIndex));
        QCheckBox *checkBox = static_cast<QCheckBox *>(widget);
        checkBox->setChecked(!checkBox->isChecked());
    }
}

void MultiSelectComboBox::SetSearchBarPlaceHolderText(const QString& aPlaceHolderText)
{
    mSearchBar->setPlaceholderText(aPlaceHolderText);
}

void MultiSelectComboBox::SetPlaceHolderText(const QString& aPlaceHolderText)
{
    mLineEdit->setPlaceholderText(aPlaceHolderText);
}

void MultiSelectComboBox::clear()
{
    mListWidget->clear();
    QListWidgetItem* curItem = new QListWidgetItem(mListWidget);
    mSearchBar = new QLineEdit(this);
    mSearchBar->setPlaceholderText("Search..");
    mSearchBar->setClearButtonEnabled(true);
    mListWidget->addItem(curItem);
    mListWidget->setItemWidget(curItem, mSearchBar);

    connect(mSearchBar, &QLineEdit::textChanged, this, &MultiSelectComboBox::onSearch);
}

void MultiSelectComboBox::wheelEvent(QWheelEvent* aWheelEvent)
{
    // Do not handle the wheel event
    Q_UNUSED(aWheelEvent);
}

bool MultiSelectComboBox::eventFilter(QObject* aObject, QEvent* aEvent)
{
    if(aObject == mLineEdit && aEvent->type() == QEvent::MouseButtonRelease) {
        showPopup();
        return false;
    }
    return false;
}

void MultiSelectComboBox::keyPressEvent(QKeyEvent* aEvent)
{
    // Do not handle key event
    Q_UNUSED(aEvent);
}

void MultiSelectComboBox::setCurrentText(const QString& aText)
{
    Q_UNUSED(aText);
}

void MultiSelectComboBox::setCurrentText(const QStringList& aText)
{
    int count = mListWidget->count();

    for (int i = 1; i < count; ++i)
    {
        QWidget* widget = mListWidget->itemWidget(mListWidget->item(i));
        QCheckBox* checkBox = static_cast<QCheckBox*>(widget);
        QString checkBoxString = checkBox->text();
        if(aText.contains(checkBoxString))
        {
            checkBox->setChecked(true);
        }
    }
}

void MultiSelectComboBox::ResetSelection()
{
    int count = mListWidget->count();

    for (int i = 1; i < count; ++i)
    {
        QWidget *widget = mListWidget->itemWidget(mListWidget->item(i));
        QCheckBox *checkBox = static_cast<QCheckBox *>(widget);
        checkBox->setChecked(false);
    }
}