/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Designer of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL-EXCEPT$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
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** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "widgetbox.h"
#include "widgetboxtreewidget.h"
#include "widgetbox_dnditem.h"

#include <QtDesigner/abstractformeditor.h>
#include <QtDesigner/abstractformwindowmanager.h>

#include <iconloader_p.h>
#include <qdesigner_utils_p.h>

#include <QtGui/qevent.h>
#include <QtWidgets/qboxlayout.h>
#include <QtWidgets/qapplication.h>
#include <QtWidgets/qtoolbar.h>
#include <QtWidgets/qlineedit.h>
#include <QtGui/qicon.h>

QT_BEGIN_NAMESPACE

namespace qdesigner_internal {

/* WidgetBoxFilterLineEdit: This widget should never have initial focus
 * (ie, be the first widget of a dialog, else, the hint cannot be displayed.
 * As it is the only focusable control in the widget box, it clears the focus
 * policy and focusses explicitly on click only (note that setting Qt::ClickFocus
 * is not sufficient for that as an ActivationFocus will occur). */

class WidgetBoxFilterLineEdit : public QLineEdit {
public:
    explicit WidgetBoxFilterLineEdit(QWidget *parent = 0) : QLineEdit(parent), m_defaultFocusPolicy(focusPolicy())
        { setFocusPolicy(Qt::NoFocus); }

protected:
    void mousePressEvent(QMouseEvent *event) override;
    void focusInEvent(QFocusEvent *e) override;

private:
    const Qt::FocusPolicy m_defaultFocusPolicy;
};

void WidgetBoxFilterLineEdit::mousePressEvent(QMouseEvent *e)
{
    if (!hasFocus()) // Explicitly focus on click.
        setFocus(Qt::OtherFocusReason);
    QLineEdit::mousePressEvent(e);
}

void WidgetBoxFilterLineEdit::focusInEvent(QFocusEvent *e)
{
    // Refuse the focus if the mouse it outside. In addition to the mouse
    // press logic, this prevents a re-focussing which occurs once
    // we actually had focus
    const Qt::FocusReason reason = e->reason();
    if (reason == Qt::ActiveWindowFocusReason || reason == Qt::PopupFocusReason) {
        const QPoint mousePos = mapFromGlobal(QCursor::pos());
        const bool refuse = !geometry().contains(mousePos);
        if (refuse) {
            e->ignore();
            return;
        }
    }
    QLineEdit::focusInEvent(e);
}

WidgetBox::WidgetBox(QDesignerFormEditorInterface *core, QWidget *parent, Qt::WindowFlags flags)
    : QDesignerWidgetBox(parent, flags),
      m_core(core),
      m_view(new WidgetBoxTreeWidget(m_core))
{

    QVBoxLayout *l = new QVBoxLayout(this);
    l->setMargin(0);
    l->setSpacing(0);

    // Prevent the filter from grabbing focus since Our view has Qt::NoFocus
    QToolBar *toolBar = new QToolBar(this);
    QLineEdit *filterWidget = new WidgetBoxFilterLineEdit(toolBar);
    filterWidget->setPlaceholderText(tr("Filter"));
    filterWidget->setClearButtonEnabled(true);
    connect(filterWidget, &QLineEdit::textChanged, m_view, &WidgetBoxTreeWidget::filter);
    toolBar->addWidget(filterWidget);
    l->addWidget(toolBar);

    // View
    connect(m_view, &WidgetBoxTreeWidget::pressed,
            this, &WidgetBox::handleMousePress);
    l->addWidget(m_view);

    setAcceptDrops (true);
}

WidgetBox::~WidgetBox() = default;

QDesignerFormEditorInterface *WidgetBox::core() const
{
    return m_core;
}

void WidgetBox::handleMousePress(const QString &name, const QString &xml, const QPoint &global_mouse_pos)
{
    if (QApplication::mouseButtons() != Qt::LeftButton)
        return;

    DomUI *ui = xmlToUi(name, xml, true);
    if (ui == 0)
        return;
    QList<QDesignerDnDItemInterface*> item_list;
    item_list.append(new WidgetBoxDnDItem(core(), ui, global_mouse_pos));
    m_core->formWindowManager()->dragItems(item_list);
}

int WidgetBox::categoryCount() const
{
    return m_view->categoryCount();
}

QDesignerWidgetBoxInterface::Category WidgetBox::category(int cat_idx) const
{
    return m_view->category(cat_idx);
}

void WidgetBox::addCategory(const Category &cat)
{
    m_view->addCategory(cat);
}

void WidgetBox::removeCategory(int cat_idx)
{
    m_view->removeCategory(cat_idx);
}

int WidgetBox::widgetCount(int cat_idx) const
{
    return m_view->widgetCount(cat_idx);
}

QDesignerWidgetBoxInterface::Widget WidgetBox::widget(int cat_idx, int wgt_idx) const
{
    return m_view->widget(cat_idx, wgt_idx);
}

void WidgetBox::addWidget(int cat_idx, const Widget &wgt)
{
    m_view->addWidget(cat_idx, wgt);
}

void WidgetBox::removeWidget(int cat_idx, int wgt_idx)
{
    m_view->removeWidget(cat_idx, wgt_idx);
}

void WidgetBox::dropWidgets(const QList<QDesignerDnDItemInterface*> &item_list, const QPoint&)
{
    m_view->dropWidgets(item_list);
}

void WidgetBox::setFileName(const QString &file_name)
{
    m_view->setFileName(file_name);
}

QString WidgetBox::fileName() const
{
    return m_view->fileName();
}

bool WidgetBox::load()
{
    return m_view->load(loadMode());
}

bool WidgetBox::loadContents(const QString &contents)
{
    return m_view->loadContents(contents);
}

bool WidgetBox::save()
{
    return m_view->save();
}

static const QDesignerMimeData *checkDragEvent(QDropEvent * event,
                                               bool acceptEventsFromWidgetBox)
{
    const QDesignerMimeData *mimeData = qobject_cast<const QDesignerMimeData *>(event->mimeData());
    if (!mimeData) {
        event->ignore();
        return 0;
    }
    // If desired, ignore a widget box drag and drop, where widget==0.
    if (!acceptEventsFromWidgetBox) {
        const bool fromWidgetBox = !mimeData->items().first()->widget();
        if (fromWidgetBox) {
            event->ignore();
            return 0;
        }
    }

    mimeData->acceptEvent(event);
    return mimeData;
}

void WidgetBox::dragEnterEvent (QDragEnterEvent * event)
{
    // We accept event originating from the widget box also here,
    // because otherwise Windows will not show the DnD pixmap.
    checkDragEvent(event, true);
}

void WidgetBox::dragMoveEvent(QDragMoveEvent * event)
{
    checkDragEvent(event, true);
}

void WidgetBox::dropEvent(QDropEvent * event)
{
    const QDesignerMimeData *mimeData = checkDragEvent(event, false);
    if (!mimeData)
        return;

    dropWidgets(mimeData->items(), event->pos());
    QDesignerMimeData::removeMovedWidgetsFromSourceForm(mimeData->items());
}

QIcon WidgetBox::iconForWidget(const QString &className, const QString &category) const
{
    Widget widgetData;
    if (!findWidget(this, className, category, &widgetData))
        return QIcon();
    return m_view->iconForWidget(widgetData.iconName());
}

}  // namespace qdesigner_internal

QT_END_NAMESPACE
