#include "FilterLineEdit.h"

#include <QTimer>

#include <QKeyEvent>

FilterLineEdit::FilterLineEdit(QWidget* parent, QList<FilterLineEdit*>* filters, int columnnum) : QLineEdit(parent), filterList(filters), columnNumber(columnnum)

{

setPlaceholderText(tr("Filter"));

#if QT_VERSION >= QT_VERSION_CHECK(5, 2, 0)

setClearButtonEnabled(true);

#endif

setProperty("column", columnnum); // Store the column number for later use

// Introduce a timer for delaying the signal triggered whenever the user changes the filter value.

// The idea here is that the textChanged() event isn't connected to the update filter slot directly anymore

// but instead there this timer mechanism in between: whenever the user changes the filter the delay timer

// is (re)started. As soon as the user stops typing the timer has a chance to trigger and call the

// delayedSignalTimerTriggered() method which then stops the timer and emits the delayed signal.

delaySignalTimer = new QTimer(this);

delaySignalTimer->setInterval(300); // This is the milliseconds of not-typing we want to wait before triggering

connect(this, SIGNAL(textChanged(QString)), delaySignalTimer, SLOT(start()));

connect(delaySignalTimer, SIGNAL(timeout()), this, SLOT(delayedSignalTimerTriggered()));

// Immediately emit the delayed filter value changed signal if the user presses the enter or the return key or

// the line edit widget loses focus

connect(this, SIGNAL(editingFinished()), this, SLOT(delayedSignalTimerTriggered()));

}

void FilterLineEdit::delayedSignalTimerTriggered()

{

// Stop the timer first to avoid triggering in intervals

delaySignalTimer->stop();

// Emit the delayed signal using the current value

emit delayedTextChanged(text());

}

void FilterLineEdit::keyReleaseEvent(QKeyEvent* event)

{

if(event->key() == Qt::Key_Tab)

{

if(columnNumber < filterList->size() - 1)

{

filterList->at(columnNumber + 1)->setFocus();

event->accept();

}

} else if(event->key() == Qt::Key_Backtab) {

if(columnNumber > 0)

{

filterList->at(columnNumber - 1)->setFocus();

event->accept();

}

}

}

void FilterLineEdit::clear()

{

// When programatically clearing the line edit's value make sure the effects are applied immediately, i.e.

// bypass the delayed signal timer

QLineEdit::clear();

delayedSignalTimerTriggered();

}

void FilterLineEdit::setText(const QString& text)

{

// When programatically setting the line edit's value make sure the effects are applied immediately, i.e.

// bypass the delayed signal timer

QLineEdit::setText(text);

delayedSignalTimerTriggered();

}