/*
 * Copyright 2008 Benjamin C. Meyer <ben@meyerhome.net>
 */

#include "SearchLineEdit.h"

#include <qevent.h>
#include <qmenu.h>
#include <qpainter.h>
#include <qstyle.h>
#include <qstyleoption.h>
#include <qdebug.h>
#include <qlayout.h>

SideWidget::SideWidget(QWidget *parent)
	: QWidget(parent)
{
}

bool SideWidget::event(QEvent *event)
{
	if (event->type() == QEvent::LayoutRequest)
		emit sizeHintChanged();
	return QWidget::event(event);
}

LineEdit::LineEdit(QWidget *parent)
	: QLineEdit(parent),
	  m_leftLayout(0),
	  m_rightLayout(0)
{
#if QT_VERSION < 0x040500
	setStyle(new LineEditStyle);
#endif
	init();
}

LineEdit::LineEdit(const QString &contents, QWidget *parent)
	: QLineEdit(contents, parent)
	, m_leftLayout(0)
	, m_rightLayout(0)
{
	init();
}

void LineEdit::init()
{
	m_leftWidget = new SideWidget(this);
	m_leftWidget->resize(0, 0);
	m_leftLayout = new QHBoxLayout(m_leftWidget);
	m_leftLayout->setContentsMargins(0, 0, 0, 0);
	if (isRightToLeft())
		m_leftLayout->setDirection(QBoxLayout::RightToLeft);
	else
		m_leftLayout->setDirection(QBoxLayout::LeftToRight);
	m_leftLayout->setSizeConstraint(QLayout::SetFixedSize);

	m_rightWidget = new SideWidget(this);
	m_rightWidget->resize(0, 0);
	m_rightLayout = new QHBoxLayout(m_rightWidget);
	if (isRightToLeft())
		m_rightLayout->setDirection(QBoxLayout::RightToLeft);
	else
		m_rightLayout->setDirection(QBoxLayout::LeftToRight);
	m_rightLayout->setContentsMargins(0, 0, 0, 0);

	QSpacerItem *horizontalSpacer = new QSpacerItem(0, 0, QSizePolicy::Expanding, QSizePolicy::Minimum);
	m_rightLayout->addItem(horizontalSpacer);

	setWidgetSpacing(3);
	connect(m_leftWidget, SIGNAL(sizeHintChanged()),
		this, SLOT(updateTextMargins()));
	connect(m_rightWidget, SIGNAL(sizeHintChanged()),
		this, SLOT(updateTextMargins()));
}

bool LineEdit::event(QEvent *event)
{
	if (event->type() == QEvent::LayoutDirectionChange) {
		if (isRightToLeft()) {
			m_leftLayout->setDirection(QBoxLayout::RightToLeft);
			m_rightLayout->setDirection(QBoxLayout::RightToLeft);
		} else {
			m_leftLayout->setDirection(QBoxLayout::LeftToRight);
			m_rightLayout->setDirection(QBoxLayout::LeftToRight);
		}
	}
	return QLineEdit::event(event);
}

void LineEdit::addWidget(QWidget *widget, WidgetPosition position)
{
	if (!widget)
		return;

	bool rtl = isRightToLeft();
	if (rtl)
		position = (position == LeftSide) ? RightSide : LeftSide;
	widget->show();
	if (position == LeftSide) {
		m_leftLayout->addWidget(widget);
	} else {
		m_rightLayout->insertWidget(1, widget);
	}
}

void LineEdit::removeWidget(QWidget *widget)
{
	if (!widget)
		return;

	m_leftLayout->removeWidget(widget);
	m_rightLayout->removeWidget(widget);
	widget->hide();
}

void LineEdit::setWidgetSpacing(int spacing)
{
	m_leftLayout->setSpacing(spacing);
	m_rightLayout->setSpacing(spacing);
	updateTextMargins();
}

int LineEdit::widgetSpacing() const
{
	return m_leftLayout->spacing();
}

int LineEdit::textMargin(WidgetPosition position) const
{
	int spacing = m_rightLayout->spacing();
	int w = 0;
	if (position == LeftSide)
		w = m_leftWidget->sizeHint().width();
	else
		w = m_rightWidget->sizeHint().width();
	if (w == 0)
		return 0;
	return w + spacing * 2;
}

void LineEdit::updateTextMargins()
{
#if QT_VERSION >= 0x040500
	int left = textMargin(LineEdit::LeftSide);
	int right = textMargin(LineEdit::RightSide);
	int top = 0;
	int bottom = 0;
	setTextMargins(left, top, right, bottom);
#else
	update();
#endif
	updateSideWidgetLocations();
}

void LineEdit::updateSideWidgetLocations()
{
	QStyleOptionFrameV2 opt;
	initStyleOption(&opt);
	QRect textRect = style()->subElementRect(QStyle::SE_LineEditContents, &opt, this);
	int spacing = m_rightLayout->spacing();
	textRect.adjust(spacing, 0, -spacing, 0);

	int left = textMargin(LineEdit::LeftSide);
#if QT_VERSION < 0x040500
	int right = textMargin(LineEdit::RightSide);
	textRect.adjust(-left, 1, right, 0);
#endif

	int midHeight = textRect.center().y();

	if (m_leftLayout->count() > 0) {
		int leftHeight = midHeight - m_leftWidget->height() / 2;
		int leftWidth = m_leftWidget->width();
		if (leftWidth == 0)
			leftHeight = midHeight - m_leftWidget->sizeHint().height() / 2;
		m_leftWidget->move(textRect.x(), leftHeight);
	}
	textRect.setX(left);
	textRect.setY(midHeight - m_rightWidget->sizeHint().height() / 2);
	textRect.setHeight(m_rightWidget->sizeHint().height());
	m_rightWidget->setGeometry(textRect);
}

void LineEdit::resizeEvent(QResizeEvent *event)
{
	updateSideWidgetLocations();
	QLineEdit::resizeEvent(event);
}

ClearButton::ClearButton(QWidget *parent)
	: QAbstractButton(parent)
{
	setCursor(Qt::ArrowCursor);
	setToolTip(tr("Clear"));
	setVisible(false);
	setFocusPolicy(Qt::NoFocus);
	setMinimumSize(22, 22);
}

void ClearButton::paintEvent(QPaintEvent *event)
{
	Q_UNUSED(event);
	QPainter painter(this);
	int height = this->height();

	painter.setRenderHint(QPainter::Antialiasing, true);
	QColor color = palette().color(QPalette::Mid);
	painter.setBrush(isDown()
			 ? palette().color(QPalette::Dark)
			 : palette().color(QPalette::Mid));
	painter.setPen(painter.brush().color());
	int size = width();
	int offset = size / 5;
	int radius = size - offset * 2;
	painter.drawEllipse(offset, offset, radius, radius);

	painter.setPen(palette().color(QPalette::Base));
	int border = offset * 2;
	painter.drawLine(border, border, width() - border, height - border);
	painter.drawLine(border, height - border, width() - border, border);
}

void ClearButton::textChanged(const QString &text)
{
	setVisible(!text.isEmpty());
}

/*
    Search icon on the left hand side of the search widget
    When a menu is set a down arrow appears
 */
class SearchButton : public QAbstractButton
{
public:
	SearchButton(QWidget *parent = 0);
	void paintEvent(QPaintEvent *event);
	QMenu *m_menu;

protected:
	void mousePressEvent(QMouseEvent *event);
};

SearchButton::SearchButton(QWidget *parent)
	: QAbstractButton(parent)
	, m_menu(0)
{
	setObjectName(QLatin1String("SearchButton"));
	setCursor(Qt::ArrowCursor);
	setFocusPolicy(Qt::NoFocus);
}

void SearchButton::mousePressEvent(QMouseEvent *event)
{
	if (m_menu && event->button() == Qt::LeftButton) {
		QWidget *p = parentWidget();
		if (p) {
			QPoint r = p->mapToGlobal(QPoint(0, p->height()));
			m_menu->exec(QPoint(r.x() + height() / 2, r.y()));
		}
		event->accept();
	}
	QAbstractButton::mousePressEvent(event);
}

void SearchButton::paintEvent(QPaintEvent *event)
{
	Q_UNUSED(event);
	QPainterPath myPath;

	int radius = (height() / 5) * 2;
	QRect circle(height() / 3 - 1, height() / 4, radius, radius);
	myPath.addEllipse(circle);

	myPath.arcMoveTo(circle, 300);
	QPointF c = myPath.currentPosition();
	int diff = height() / 7;
	myPath.lineTo(qMin(width() - 2, (int)c.x() + diff), c.y() + diff);

	QPainter painter(this);
	painter.setRenderHint(QPainter::Antialiasing, true);
	painter.setPen(QPen(Qt::darkGray, 2));
	painter.drawPath(myPath);

	if (m_menu) {
		QPainterPath dropPath;
		dropPath.arcMoveTo(circle, 320);
		QPointF c = dropPath.currentPosition();
		c = QPointF(c.x() + 3.5, c.y() + 0.5);
		dropPath.moveTo(c);
		dropPath.lineTo(c.x() + 4, c.y());
		dropPath.lineTo(c.x() + 2, c.y() + 2);
		dropPath.closeSubpath();
		painter.setPen(Qt::darkGray);
		painter.setBrush(Qt::darkGray);
		painter.setRenderHint(QPainter::Antialiasing, false);
		painter.drawPath(dropPath);
	}
	painter.end();
}

/*
    SearchLineEdit is an enhanced QLineEdit
    - A Search icon on the left with optional menu
    - When there is no text and doesn't have focus an "inactive text" is displayed
    - When there is text a clear button is displayed on the right hand side
 */
SearchLineEdit::SearchLineEdit(QWidget *parent)
	: LineEdit(parent),
	  m_searchButton(0)
{
	setUpdatesEnabled(false);
	m_searchButton = new SearchButton(this);
	updateGeometries();
	addWidget(m_searchButton, LeftSide);
	m_inactiveText = tr("Search");

	QSizePolicy policy = sizePolicy();
	setSizePolicy(QSizePolicy::Preferred, policy.verticalPolicy());

	// clear button on the right
	ClearButton *m_clearButton = new ClearButton(this);
	connect(m_clearButton, SIGNAL(clicked()),
		this, SLOT(clear()));
	connect(this, SIGNAL(textChanged(const QString&)),
		m_clearButton, SLOT(textChanged(const QString&)));
	addWidget(m_clearButton, RightSide);
	m_clearButton->hide();
	updateTextMargins();
	setUpdatesEnabled(true);
}

void SearchLineEdit::paintEvent(QPaintEvent *event)
{
	if (text().isEmpty() && !hasFocus() && !m_inactiveText.isEmpty()) {
		LineEdit::paintEvent(event);
		QStyleOptionFrameV2 panel;
		initStyleOption(&panel);
		QRect textRect = style()->subElementRect(QStyle::SE_LineEditContents, &panel, this);
#if QT_VERSION >= 0x040500
		int left = textMargin(LineEdit::LeftSide);
		int right = textMargin(LineEdit::RightSide);
		textRect.adjust(left, 0, -right, 0);
#endif
		QPainter painter(this);
		painter.setPen(palette().brush(QPalette::Disabled, QPalette::Text).color());
		painter.drawText(textRect, Qt::AlignLeft | Qt::AlignVCenter, m_inactiveText);
	} else {
		LineEdit::paintEvent(event);
	}
}

void SearchLineEdit::resizeEvent(QResizeEvent *event)
{
	updateGeometries();
	LineEdit::resizeEvent(event);
}

void SearchLineEdit::updateGeometries()
{
	int menuHeight = height();
	int menuWidth = menuHeight + 1;
	if (!m_searchButton->m_menu)
		menuWidth = (menuHeight / 5) * 4;
	m_searchButton->setMinimumSize(QSize(menuWidth, menuHeight));
	m_searchButton->resize(menuWidth, menuHeight);
	updateTextMargins();
}

QString SearchLineEdit::inactiveText() const
{
	return m_inactiveText;
}

void SearchLineEdit::setInactiveText(const QString &text)
{
	m_inactiveText = text;
}

void SearchLineEdit::setMenu(QMenu *menu)
{
	if (m_searchButton->m_menu)
		m_searchButton->m_menu->deleteLater();
	m_searchButton->m_menu = menu;
	updateGeometries();
}

QMenu* SearchLineEdit::menu() const
{
	if (!m_searchButton->m_menu) {
		m_searchButton->m_menu = new QMenu(m_searchButton);
		if (isVisible())
			(const_cast<SearchLineEdit*>(this))->updateGeometries();
	}
	return m_searchButton->m_menu;
}