/****************************************************************************
**
** Copyright (C) 1992-2004 Trolltech AS. All rights reserved.
**
** This file is part of the widgets module of the Qt Toolkit.
**
** This file may be distributed under the terms of the Q Public License
** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for
**   information about Qt Commercial License Agreements.
** See http://www.trolltech.com/qpl/ for QPL licensing information.
** See http://www.trolltech.com/gpl/ for GPL licensing information.
**
** Contact info@trolltech.com if any conditions of this licensing are
** not clear to you.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qwidgetresizehandler_p.h"

#ifndef QT_NO_RESIZEHANDLER
#include "qframe.h"
#include "qapplication.h"
#include "qdesktopwidget.h"
#include "qcursor.h"
#include "qsizegrip.h"
#include "qevent.h"
#if defined(Q_WS_WIN)
#include "qt_windows.h"
#endif

#define RANGE 4

static bool resizeHorizontalDirectionFixed = false;
static bool resizeVerticalDirectionFixed = false;

QWidgetResizeHandler::QWidgetResizeHandler(QWidget *parent, QWidget *cw)
    : QObject(parent), widget(parent), childWidget(cw ? cw : parent),
      extrahei(0), buttonDown(false), moveResizeMode(false), sizeprotect(true), moving(true)
{
    mode = Nowhere;
    widget->setMouseTracking(true);
    QFrame *frame = qt_cast<QFrame*>(widget);
    range = frame ? frame->frameWidth() : RANGE;
    range = qMax(RANGE, range);
    activeForMove = activeForResize = true;
    qApp->installEventFilter(this);
}

void QWidgetResizeHandler::setActive(Action ac, bool b)
{
    if (ac & Move)
        activeForMove = b;
    if (ac & Resize)
        activeForResize = b;

    if (!isActive())
        setMouseCursor(Nowhere);
}

bool QWidgetResizeHandler::isActive(Action ac) const
{
    bool b = false;
    if (ac & Move) b = activeForMove;
    if (ac & Resize) b |= activeForResize;

    return b;
}

static QWidget *childOf(QWidget *w, QWidget *child)
{
    while (child) {
        if (child == w)
            return child;
        if (child->isTopLevel())
            break;
        child = child->parentWidget();
    }
    return 0;
}

bool QWidgetResizeHandler::eventFilter(QObject *o, QEvent *ee)
{
    if (!isActive() || !o->isWidgetType() || !ee->spontaneous())
        return false;

    if (ee->type() != QEvent::MouseButtonPress &&
         ee->type() != QEvent::MouseButtonRelease &&
         ee->type() != QEvent::MouseMove &&
         ee->type() != QEvent::KeyPress &&
         ee->type() != QEvent::ShortcutOverride)
        return false;

    QWidget *w = childOf(widget, (QWidget*)o);
    if (!w
#ifndef QT_NO_SIZEGRIP
         || qt_cast<QSizeGrip*>(o)
#endif
         || qApp->activePopupWidget()) {
        if (buttonDown && ee->type() == QEvent::MouseButtonRelease)
            buttonDown = false;
        return false;
    }

    QMouseEvent *e = (QMouseEvent*)ee;
    switch (e->type()) {
    case QEvent::MouseButtonPress: {
        if (w->isMaximized())
            break;
        if (!widget->rect().contains(widget->mapFromGlobal(e->globalPos())))
            return false;
        if (e->button() == Qt::LeftButton) {
            emit activate();
            bool me = isMovingEnabled();
            setMovingEnabled(me && o == widget);
            mouseMoveEvent(e);
            setMovingEnabled(me);
            buttonDown = true;
            moveOffset = widget->mapFromGlobal(e->globalPos());
            invertedMoveOffset = widget->rect().bottomRight() - moveOffset;
        }
    } break;
    case QEvent::MouseButtonRelease:
        if (w->isMaximized())
            break;
        if (e->button() == Qt::LeftButton) {
            moveResizeMode = false;
            buttonDown = false;
            widget->releaseMouse();
            widget->releaseKeyboard();
        }
        break;
    case QEvent::MouseMove: {
        if (w->isMaximized())
            break;
        bool me = isMovingEnabled();
        setMovingEnabled(me && o == widget);
        mouseMoveEvent(e);
        setMovingEnabled(me);
        if (buttonDown && mode != Center)
            return true;
    } break;
    case QEvent::KeyPress:
        keyPressEvent((QKeyEvent*)e);
        break;
    case QEvent::ShortcutOverride:
        if (buttonDown) {
            ((QKeyEvent*)ee)->accept();
            return true;
        }
        break;
    default:
        break;
    }
    return false;
}

void QWidgetResizeHandler::mouseMoveEvent(QMouseEvent *e)
{
    QPoint pos = widget->mapFromGlobal(e->globalPos());
    if (!moveResizeMode && (!buttonDown || (e->buttons() & Qt::LeftButton) == 0)) {
        if (pos.y() <= range && pos.x() <= range)
            mode = TopLeft;
        else if (pos.y() >= widget->height()-range && pos.x() >= widget->width()-range)
            mode = BottomRight;
        else if (pos.y() >= widget->height()-range && pos.x() <= range)
            mode = BottomLeft;
        else if (pos.y() <= range && pos.x() >= widget->width()-range)
            mode = TopRight;
        else if (pos.y() <= range)
            mode = Top;
        else if (pos.y() >= widget->height()-range)
            mode = Bottom;
        else if (pos.x() <= range)
            mode = Left;
        else if ( pos.x() >= widget->width()-range)
            mode = Right;
        else
            mode = Center;

        if (widget->isMinimized() || !isActive(Resize))
            mode = Center;
#ifndef QT_NO_CURSOR
        setMouseCursor(mode);
#endif
        return;
    }

    if (buttonDown && !isMovingEnabled() && mode == Center && !moveResizeMode)
        return;

    if (widget->testWState(Qt::WState_ConfigPending))
        return;


    QPoint globalPos = (!widget->isTopLevel() && widget->parentWidget()) ?
                       widget->parentWidget()->mapFromGlobal(e->globalPos()) : e->globalPos();
    if (!widget->isTopLevel() && !widget->parentWidget()->rect().contains(globalPos)) {
        if (globalPos.x() < 0)
            globalPos.rx() = 0;
        if (globalPos.y() < 0)
            globalPos.ry() = 0;
        if (sizeprotect && globalPos.x() > widget->parentWidget()->width())
            globalPos.rx() = widget->parentWidget()->width();
        if (sizeprotect && globalPos.y() > widget->parentWidget()->height())
            globalPos.ry() = widget->parentWidget()->height();
    }

    QPoint p = globalPos + invertedMoveOffset;
    QPoint pp = globalPos - moveOffset;

    int fw = 0;
    int mw = qMax(childWidget->minimumSizeHint().width(),
                   childWidget->minimumWidth());
    int mh = qMax(childWidget->minimumSizeHint().height(),
                   childWidget->minimumHeight());
    if (childWidget != widget) {
        QFrame *frame = qt_cast<QFrame*>(widget);
        if (frame)
            fw = frame->frameWidth();
        mw += 2 * fw;
        mh += 2 * fw + extrahei;
    }

    QSize mpsize(widget->geometry().right() - pp.x() + 1,
                  widget->geometry().bottom() - pp.y() + 1);
    mpsize = mpsize.expandedTo(widget->minimumSize()).expandedTo(QSize(mw, mh));
    QPoint mp(widget->geometry().right() - mpsize.width() + 1,
               widget->geometry().bottom() - mpsize.height() + 1);

    QRect geom = widget->geometry();

    switch (mode) {
    case TopLeft:
        geom = QRect(mp, widget->geometry().bottomRight()) ;
        break;
    case BottomRight:
        geom = QRect(widget->geometry().topLeft(), p) ;
        break;
    case BottomLeft:
        geom = QRect(QPoint(mp.x(), widget->geometry().y()), QPoint(widget->geometry().right(), p.y())) ;
        break;
    case TopRight:
        geom = QRect(QPoint(widget->geometry().x(), mp.y()), QPoint(p.x(), widget->geometry().bottom())) ;
        break;
    case Top:
        geom = QRect(QPoint(widget->geometry().left(), mp.y()), widget->geometry().bottomRight()) ;
        break;
    case Bottom:
        geom = QRect(widget->geometry().topLeft(), QPoint(widget->geometry().right(), p.y())) ;
        break;
    case Left:
        geom = QRect(QPoint(mp.x(), widget->geometry().top()), widget->geometry().bottomRight()) ;
        break;
    case Right:
        geom = QRect(widget->geometry().topLeft(), QPoint(p.x(), widget->geometry().bottom())) ;
        break;
    case Center:
        if (isMovingEnabled() || moveResizeMode)
            geom.moveTopLeft(pp);
        break;
    default:
        break;
    }

    QSize maxsize(childWidget->maximumSize());
    if (childWidget != widget)
        maxsize += QSize(2 * fw, 2 * fw + extrahei);

    geom = QRect(geom.topLeft(),
                  geom.size().expandedTo(widget->minimumSize())
                             .expandedTo(QSize(mw, mh))
                             .boundedTo(maxsize));

    if (geom != widget->geometry() &&
        (widget->isTopLevel() || widget->parentWidget()->rect().intersects(geom))) {
        if (widget->isMinimized())
            widget->move(geom.topLeft());
        else
            widget->setGeometry(geom);
    }

#if defined(Q_WS_WIN)
    MSG msg;
    QT_WA({
        while(PeekMessageW(&msg, widget->winId(), WM_MOUSEMOVE, WM_MOUSEMOVE, PM_REMOVE))
            ;
    } , {
        while(PeekMessageA(&msg, widget->winId(), WM_MOUSEMOVE, WM_MOUSEMOVE, PM_REMOVE))
            ;
    });
#endif

    QApplication::syncX();
}

void QWidgetResizeHandler::setMouseCursor(MousePosition m)
{
#ifndef QT_NO_CURSOR
    switch (m) {
    case TopLeft:
    case BottomRight:
        widget->setCursor(Qt::SizeFDiagCursor);
        break;
    case BottomLeft:
    case TopRight:
        widget->setCursor(Qt::SizeBDiagCursor);
        break;
    case Top:
    case Bottom:
        widget->setCursor(Qt::SizeVerCursor);
        break;
    case Left:
    case Right:
        widget->setCursor(Qt::SizeHorCursor);
        break;
    default:
        widget->setCursor(Qt::ArrowCursor);
        break;
    }
#endif
}

void QWidgetResizeHandler::keyPressEvent(QKeyEvent * e)
{
    if (!isMove() && !isResize())
        return;
    bool is_control = e->modifiers() & Qt::ControlModifier;
    int delta = is_control?1:8;
    QPoint pos = QCursor::pos();
    switch (e->key()) {
    case Qt::Key_Left:
        pos.rx() -= delta;
        if (pos.x() <= QApplication::desktop()->geometry().left()) {
            if (mode == TopLeft || mode == BottomLeft) {
                moveOffset.rx() += delta;
                invertedMoveOffset.rx() += delta;
            } else {
                moveOffset.rx() -= delta;
                invertedMoveOffset.rx() -= delta;
            }
        }
        if (isResize() && !resizeHorizontalDirectionFixed) {
            resizeHorizontalDirectionFixed = true;
            if (mode == BottomRight)
                mode = BottomLeft;
            else if (mode == TopRight)
                mode = TopLeft;
#ifndef QT_NO_CURSOR
            setMouseCursor(mode);
            widget->grabMouse(widget->cursor());
#else
            widget->grabMouse();
#endif
        }
        break;
    case Qt::Key_Right:
        pos.rx() += delta;
        if (pos.x() >= QApplication::desktop()->geometry().right()) {
            if (mode == TopRight || mode == BottomRight) {
                moveOffset.rx() += delta;
                invertedMoveOffset.rx() += delta;
            } else {
                moveOffset.rx() -= delta;
                invertedMoveOffset.rx() -= delta;
            }
        }
        if (isResize() && !resizeHorizontalDirectionFixed) {
            resizeHorizontalDirectionFixed = true;
            if (mode == BottomLeft)
                mode = BottomRight;
            else if (mode == TopLeft)
                mode = TopRight;
#ifndef QT_NO_CURSOR
            setMouseCursor(mode);
            widget->grabMouse(widget->cursor());
#else
            widget->grabMouse();
#endif
        }
        break;
    case Qt::Key_Up:
        pos.ry() -= delta;
        if (pos.y() <= QApplication::desktop()->geometry().top()) {
            if (mode == TopLeft || mode == TopRight) {
                moveOffset.ry() += delta;
                invertedMoveOffset.ry() += delta;
            } else {
                moveOffset.ry() -= delta;
                invertedMoveOffset.ry() -= delta;
            }
        }
        if (isResize() && !resizeVerticalDirectionFixed) {
            resizeVerticalDirectionFixed = true;
            if (mode == BottomLeft)
                mode = TopLeft;
            else if (mode == BottomRight)
                mode = TopRight;
#ifndef QT_NO_CURSOR
            setMouseCursor(mode);
            widget->grabMouse(widget->cursor());
#else
            widget->grabMouse();
#endif
        }
        break;
    case Qt::Key_Down:
        pos.ry() += delta;
        if (pos.y() >= QApplication::desktop()->geometry().bottom()) {
            if (mode == BottomLeft || mode == BottomRight) {
                moveOffset.ry() += delta;
                invertedMoveOffset.ry() += delta;
            } else {
                moveOffset.ry() -= delta;
                invertedMoveOffset.ry() -= delta;
            }
        }
        if (isResize() && !resizeVerticalDirectionFixed) {
            resizeVerticalDirectionFixed = true;
            if (mode == TopLeft)
                mode = BottomLeft;
            else if (mode == TopRight)
                mode = BottomRight;
#ifndef QT_NO_CURSOR
            setMouseCursor(mode);
            widget->grabMouse(widget->cursor());
#else
            widget->grabMouse();
#endif
        }
        break;
    case Qt::Key_Space:
    case Qt::Key_Return:
    case Qt::Key_Enter:
    case Qt::Key_Escape:
        moveResizeMode = false;
        widget->releaseMouse();
        widget->releaseKeyboard();
        buttonDown = false;
        break;
    default:
        return;
    }
    QCursor::setPos(pos);
}


void QWidgetResizeHandler::doResize()
{
    if (!activeForResize)
        return;

    moveResizeMode = true;
    buttonDown = true;
    moveOffset = widget->mapFromGlobal(QCursor::pos());
    if (moveOffset.x() < widget->width()/2) {
        if (moveOffset.y() < widget->height()/2)
            mode = TopLeft;
        else
            mode = BottomLeft;
    } else {
        if (moveOffset.y() < widget->height()/2)
            mode = TopRight;
        else
            mode = BottomRight;
    }
    invertedMoveOffset = widget->rect().bottomRight() - moveOffset;
#ifndef QT_NO_CURSOR
    setMouseCursor(mode);
    widget->grabMouse(widget->cursor() );
#else
    widget->grabMouse();
#endif
    widget->grabKeyboard();
    resizeHorizontalDirectionFixed = false;
    resizeVerticalDirectionFixed = false;
}

void QWidgetResizeHandler::doMove()
{
    if (!activeForMove)
        return;

    mode = Center;
    moveResizeMode = true;
    buttonDown = true;
    moveOffset = widget->mapFromGlobal(QCursor::pos());
    invertedMoveOffset = widget->rect().bottomRight() - moveOffset;
#ifndef QT_NO_CURSOR
    widget->grabMouse(Qt::SizeAllCursor);
#else
    widget->grabMouse();
#endif
    widget->grabKeyboard();
}

#endif //QT_NO_RESIZEHANDLER
