qwidgetresizehandler.cpp

奇趣公司比较新的qt/emd版本

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#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
#include "qdebug.h"
#include "private/qlayoutengine_p.h"

#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),
      fw(0), extrahei(0), buttonDown(false), moveResizeMode(false), sizeprotect(true), movingEnabled(true)
{
    mode = Nowhere;
    widget->setMouseTracking(true);
    QFrame *frame = qobject_cast<QFrame*>(widget);
    range = frame ? frame->frameWidth() : RANGE;
    range = qMax(RANGE, range);
    activeForMove = activeForResize = true;
    widget->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;
}

bool QWidgetResizeHandler::eventFilter(QObject *o, QEvent *ee)
{
    if (!isActive()
        || (ee->type() != QEvent::MouseButtonPress
            && ee->type() != QEvent::MouseButtonRelease
            && ee->type() != QEvent::MouseMove
            && ee->type() != QEvent::KeyPress
            && ee->type() != QEvent::ShortcutOverride)
        )
        return false;

    Q_ASSERT(o == widget);
    QWidget *w = widget;
    if (QApplication::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) {
#if defined(Q_WS_X11)
            /*
               Implicit grabs do not stop the X server from changing
               the cursor in children, which looks *really* bad when
               doing resizingk, so we grab the cursor. Note that we do
               not do this on Windows since double clicks are lost due
               to the grab (see change 198463).
            */
            if (e->spontaneous())
#  if !defined(QT_NO_CURSOR)
                widget->grabMouse(widget->cursor());
#  else
                widget->grabMouse();
#  endif // QT_NO_CURSOR
#endif // Q_WS_X11
            buttonDown = false;
            emit activate();
            bool me = movingEnabled;
            movingEnabled = (me && o == widget);
            mouseMoveEvent(e);
            movingEnabled = me;
            buttonDown = true;
            moveOffset = widget->mapFromGlobal(e->globalPos());
            invertedMoveOffset = widget->rect().bottomRight() - moveOffset;
            if (mode == Center) {
                if (movingEnabled)
                    return true;
            } else {
                return true;
            }
        }
    } break;
    case QEvent::MouseButtonRelease:
        if (w->isMaximized())
            break;
        if (e->button() == Qt::LeftButton) {
            moveResizeMode = false;
            buttonDown = false;
            widget->releaseMouse();
            widget->releaseKeyboard();
            if (mode == Center) {
                if (movingEnabled)
                    return true;
            } else {
                return true;
            }
        }
        break;
    case QEvent::MouseMove: {
        if (w->isMaximized())
            break;
        buttonDown = buttonDown && (e->buttons() & Qt::LeftButton); // safety, state machine broken!
        bool me = movingEnabled;
        movingEnabled = (me && o == widget && (buttonDown || moveResizeMode));
        mouseMoveEvent(e);
        movingEnabled = me;
        if (mode == Center) {
            if (movingEnabled)
                return true;
        } else {
            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) {
        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 if (widget->rect().contains(pos))
            mode = Center;
        else
            mode = Nowhere;

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

    if (mode == Center && !movingEnabled)
        return;

    if (widget->testAttribute(Qt::WA_WState_ConfigPending))
        return;


    QPoint globalPos = (!widget->isWindow() && widget->parentWidget()) ?
                       widget->parentWidget()->mapFromGlobal(e->globalPos()) : e->globalPos();
    if (!widget->isWindow() && !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;

#ifdef Q_WS_X11
    // Workaround for window managers which refuse to move a tool window partially offscreen.
    QRect desktop = qApp->desktop()->availableGeometry(widget);
    pp.rx() = qMax(pp.x(), desktop.left());
    pp.ry() = qMax(pp.y(), desktop.top());
    p.rx() = qMin(p.x(), desktop.right());
    p.ry() = qMin(p.y(), desktop.bottom());
#endif

    QSize ms = qSmartMinSize(childWidget);
    int mw = ms.width();
    int mh = ms.height();
    if (childWidget != widget) {
        mw += 2 * fw;
        mh += 2 * fw + extrahei;
    }

    QSize maxsize(childWidget->maximumSize());
    if (childWidget != widget)