summaryrefslogtreecommitdiffstats
path: root/src/gui/widgets/qsizegrip.cpp
blob: 080e32866e1f9cafafcfcf91554c8e321c0301f7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://qt.nokia.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qsizegrip.h"

#ifndef QT_NO_SIZEGRIP

#include "qapplication.h"
#include "qevent.h"
#include "qpainter.h"
#include "qstyle.h"
#include "qstyleoption.h"
#include "qlayout.h"
#include "qdebug.h"
#include <QDesktopWidget>

#if defined(Q_WS_X11)
#include <private/qt_x11_p.h>
#elif defined (Q_WS_WIN)
#include "qt_windows.h"
#endif
#ifdef Q_WS_MAC
#include <private/qt_mac_p.h>
#endif

#include <private/qwidget_p.h>
#include <QtGui/qabstractscrollarea.h>

#define SZ_SIZEBOTTOMRIGHT  0xf008
#define SZ_SIZEBOTTOMLEFT   0xf007
#define SZ_SIZETOPLEFT      0xf004
#define SZ_SIZETOPRIGHT     0xf005

QT_BEGIN_NAMESPACE

static QWidget *qt_sizegrip_topLevelWidget(QWidget* w)
{
    while (w && !w->isWindow() && w->windowType() != Qt::SubWindow)
        w = w->parentWidget();
    return w;
}

static inline bool hasHeightForWidth(QWidget *widget)
{
    if (!widget)
        return false;
    if (QLayout *layout = widget->layout())
        return layout->hasHeightForWidth();
    return widget->sizePolicy().hasHeightForWidth();
}

class QSizeGripPrivate : public QWidgetPrivate
{
    Q_DECLARE_PUBLIC(QSizeGrip)
public:
    void init();
    QPoint p;
    QRect r;
    int d;
    int dxMax;
    int dyMax;
    Qt::Corner m_corner;
    bool gotMousePress;
#ifdef Q_WS_MAC
    void updateMacSizer(bool hide) const;
#endif
    Qt::Corner corner() const;
    inline bool atBottom() const
    {
        return m_corner == Qt::BottomRightCorner || m_corner == Qt::BottomLeftCorner;
    }

    inline bool atLeft() const
    {
        return m_corner == Qt::BottomLeftCorner || m_corner == Qt::TopLeftCorner;
    }

    // This slot is invoked by QLayout when the size grip is added to
    // a layout or reparented after the tlw is shown. This re-implementation is basically
    // the same as QWidgetPrivate::_q_showIfNotHidden except that it checks
    // for Qt::WindowFullScreen and Qt::WindowMaximized as well.
    void _q_showIfNotHidden()
    {
        Q_Q(QSizeGrip);
        bool showSizeGrip = !(q->isHidden() && q->testAttribute(Qt::WA_WState_ExplicitShowHide));
        QWidget *tlw = qt_sizegrip_topLevelWidget(q);
        if (tlw && showSizeGrip) {
            Qt::WindowStates sizeGripNotVisibleState = Qt::WindowFullScreen;
#ifndef Q_WS_MAC
            sizeGripNotVisibleState |= Qt::WindowMaximized;
#endif
            // Don't show the size grip if the tlw is maximized or in full screen mode.
            showSizeGrip = !(tlw->windowState() & sizeGripNotVisibleState);
        }
        if (showSizeGrip)
            q->setVisible(true);
    }
};

#ifdef Q_WS_MAC
void QSizeGripPrivate::updateMacSizer(bool hide) const
{
    Q_Q(const QSizeGrip);
    if (QApplication::closingDown() || !parent)
        return;
    QWidget *topLevelWindow = qt_sizegrip_topLevelWidget(const_cast<QSizeGrip *>(q));
    if(topLevelWindow && topLevelWindow->isWindow())
        QWidgetPrivate::qt_mac_update_sizer(topLevelWindow, hide ? -1 : 1);
}
#endif

Qt::Corner QSizeGripPrivate::corner() const
{
    Q_Q(const QSizeGrip);
    QWidget *tlw = qt_sizegrip_topLevelWidget(const_cast<QSizeGrip *>(q));
    const QPoint sizeGripPos = q->mapTo(tlw, QPoint(0, 0));
    bool isAtBottom = sizeGripPos.y() >= tlw->height() / 2;
    bool isAtLeft = sizeGripPos.x() <= tlw->width() / 2;
    if (isAtLeft)
        return isAtBottom ? Qt::BottomLeftCorner : Qt::TopLeftCorner;
    else
        return isAtBottom ? Qt::BottomRightCorner : Qt::TopRightCorner;
}

/*!
    \class QSizeGrip

    \brief The QSizeGrip class provides a resize handle for resizing top-level windows.

    \ingroup application
    \ingroup basicwidgets
    \ingroup appearance

    This widget works like the standard Windows resize handle. In the
    X11 version this resize handle generally works differently from
    the one provided by the system if the X11 window manager does not
    support necessary modern post-ICCCM specifications.

    Put this widget anywhere in a widget tree and the user can use it
    to resize the top-level window or any widget with the Qt::SubWindow
    flag set. Generally, this should be in the lower right-hand corner.
    Note that QStatusBar already uses this widget, so if you have a
    status bar (e.g., you are using QMainWindow), then you don't need
    to use this widget explicitly.

    On some platforms the size grip automatically hides itself when the
    window is shown full screen or maximised.

    \table 50%
    \row \o \inlineimage plastique-sizegrip.png Screenshot of a Plastique style size grip
    \o A size grip widget at the bottom-right corner of a main window, shown in the
    \l{Plastique Style Widget Gallery}{Plastique widget style}.
    \endtable

    The QSizeGrip class inherits QWidget and reimplements the \l
    {QWidget::mousePressEvent()}{mousePressEvent()} and \l
    {QWidget::mouseMoveEvent()}{mouseMoveEvent()} functions to feature
    the resize functionality, and the \l
    {QWidget::paintEvent()}{paintEvent()} function to render the
    size grip widget.

    \sa QStatusBar QWidget::windowState()
*/


/*!
    Constructs a resize corner as a child widget of  the given \a
    parent.
*/
QSizeGrip::QSizeGrip(QWidget * parent)
    : QWidget(*new QSizeGripPrivate, parent, 0)
{
    Q_D(QSizeGrip);
    d->init();
}

#ifdef QT3_SUPPORT
/*!
    \obsolete

    Constructs a resize corner with the given \a name, as a child
    widget of the given \a parent.
*/
QSizeGrip::QSizeGrip(QWidget * parent, const char* name)
    : QWidget(*new QSizeGripPrivate, parent, 0)
{
    Q_D(QSizeGrip);
    setObjectName(QString::fromAscii(name));
    d->init();
}
#endif

void QSizeGripPrivate::init()
{
    Q_Q(QSizeGrip);
    dxMax = 0;
    dyMax = 0;
    m_corner = q->isLeftToRight() ? Qt::BottomRightCorner : Qt::BottomLeftCorner;
    gotMousePress = false;

#if !defined(QT_NO_CURSOR) && !defined(Q_WS_MAC)
    q->setCursor(m_corner == Qt::TopLeftCorner || m_corner == Qt::BottomRightCorner
                 ? Qt::SizeFDiagCursor : Qt::SizeBDiagCursor);
#endif
    q->setSizePolicy(QSizePolicy(QSizePolicy::Minimum, QSizePolicy::Fixed));
    QWidget *tlw = qt_sizegrip_topLevelWidget(q);
    tlw->installEventFilter(q);
}


/*!
    Destroys this size grip.
*/
QSizeGrip::~QSizeGrip()
{
}

/*!
  \reimp
*/
QSize QSizeGrip::sizeHint() const
{
    QStyleOption opt(0);
    opt.init(this);
    return (style()->sizeFromContents(QStyle::CT_SizeGrip, &opt, QSize(13, 13), this).
            expandedTo(QApplication::globalStrut()));
}

/*!
    Paints the resize grip.

    Resize grips are usually rendered as small diagonal textured lines
    in the lower-right corner. The paint event is passed in the \a
    event parameter.
*/
void QSizeGrip::paintEvent(QPaintEvent *event)
{
    Q_UNUSED(event);
    Q_D(QSizeGrip);
    QPainter painter(this);
    QStyleOptionSizeGrip opt;
    opt.init(this);
    opt.corner = d->m_corner;
    style()->drawControl(QStyle::CE_SizeGrip, &opt, &painter, this);
}

/*!
    \fn void QSizeGrip::mousePressEvent(QMouseEvent * event)

    Receives the mouse press events for the widget, and primes the
    resize operation. The mouse press event is passed in the \a event
    parameter.
*/
void QSizeGrip::mousePressEvent(QMouseEvent * e)
{
    if (e->button() != Qt::LeftButton) {
        QWidget::mousePressEvent(e);
        return;
    }

    Q_D(QSizeGrip);
    QWidget *tlw = qt_sizegrip_topLevelWidget(this);
    d->p = e->globalPos();
    d->gotMousePress = true;
    d->r = tlw->geometry();

#ifdef Q_WS_X11
    // Use a native X11 sizegrip for "real" top-level windows if supported.
    if (tlw->isWindow() && X11->isSupportedByWM(ATOM(_NET_WM_MOVERESIZE))
        && !tlw->testAttribute(Qt::WA_DontShowOnScreen) && !hasHeightForWidth(tlw)) {
        XEvent xev;
        xev.xclient.type = ClientMessage;
        xev.xclient.message_type = ATOM(_NET_WM_MOVERESIZE);
        xev.xclient.display = X11->display;
        xev.xclient.window = tlw->winId();
        xev.xclient.format = 32;
        xev.xclient.data.l[0] = e->globalPos().x();
        xev.xclient.data.l[1] = e->globalPos().y();
        if (d->atBottom())
            xev.xclient.data.l[2] = d->atLeft() ? 6 : 4; // bottomleft/bottomright
        else
            xev.xclient.data.l[2] = d->atLeft() ? 0 : 2; // topleft/topright
        xev.xclient.data.l[3] = Button1;
        xev.xclient.data.l[4] = 0;
        XUngrabPointer(X11->display, X11->time);
        XSendEvent(X11->display, QX11Info::appRootWindow(x11Info().screen()), False,
                   SubstructureRedirectMask | SubstructureNotifyMask, &xev);
        return;
    }
#endif // Q_WS_X11
#ifdef Q_WS_WIN
    if (tlw->isWindow() && !tlw->testAttribute(Qt::WA_DontShowOnScreen) && !hasHeightForWidth(tlw)) {
        uint orientation = 0;
        if (d->atBottom())
            orientation = d->atLeft() ? SZ_SIZEBOTTOMLEFT : SZ_SIZEBOTTOMRIGHT;
        else
            orientation = d->atLeft() ? SZ_SIZETOPLEFT : SZ_SIZETOPRIGHT;

        ReleaseCapture();
        PostMessage(tlw->winId(), WM_SYSCOMMAND, orientation, 0);
        return;
    }
#endif // Q_WS_WIN

    // Find available desktop/workspace geometry.
    QRect availableGeometry;
    bool hasVerticalSizeConstraint = true;
    bool hasHorizontalSizeConstraint = true;
    if (tlw->isWindow())
        availableGeometry = QApplication::desktop()->availableGeometry(tlw);
    else {
        const QWidget *tlwParent = tlw->parentWidget();
        // Check if tlw is inside QAbstractScrollArea/QScrollArea.
        // If that's the case tlw->parentWidget() will return the viewport
        // and tlw->parentWidget()->parentWidget() will return the scroll area.
#ifndef QT_NO_SCROLLAREA
        QAbstractScrollArea *scrollArea = qobject_cast<QAbstractScrollArea *>(tlwParent->parentWidget());
        if (scrollArea) {
            hasHorizontalSizeConstraint = scrollArea->horizontalScrollBarPolicy() == Qt::ScrollBarAlwaysOff;
            hasVerticalSizeConstraint = scrollArea->verticalScrollBarPolicy() == Qt::ScrollBarAlwaysOff;
        }
#endif // QT_NO_SCROLLAREA
        availableGeometry = tlwParent->contentsRect();
    }

    // Find frame geometries, title bar height, and decoration sizes.
    const QRect frameGeometry = tlw->frameGeometry();
    const int titleBarHeight = qMax(tlw->geometry().y() - frameGeometry.y(), 0);
    const int bottomDecoration = qMax(frameGeometry.height() - tlw->height() - titleBarHeight, 0);
    const int leftRightDecoration = qMax((frameGeometry.width() - tlw->width()) / 2, 0);

    // Determine dyMax depending on whether the sizegrip is at the bottom
    // of the widget or not.
    if (d->atBottom()) {
        if (hasVerticalSizeConstraint)
            d->dyMax = availableGeometry.bottom() - d->r.bottom() - bottomDecoration;
        else
            d->dyMax = INT_MAX;
    } else {
        if (hasVerticalSizeConstraint)
            d->dyMax = availableGeometry.y() - d->r.y() + titleBarHeight;
        else
            d->dyMax = -INT_MAX;
    }

    // In RTL mode, the size grip is to the left; find dxMax from the desktop/workspace
    // geometry, the size grip geometry and the width of the decoration.
    if (d->atLeft()) {
        if (hasHorizontalSizeConstraint)
            d->dxMax = availableGeometry.x() - d->r.x() + leftRightDecoration;
        else
            d->dxMax = -INT_MAX;
    } else {
        if (hasHorizontalSizeConstraint)
            d->dxMax = availableGeometry.right() - d->r.right() - leftRightDecoration;
        else
            d->dxMax = INT_MAX;
    }
}


/*!
    \fn void QSizeGrip::mouseMoveEvent(QMouseEvent * event)
    Resizes the top-level widget containing this widget. The mouse
    move event is passed in the \a event parameter.
*/
void QSizeGrip::mouseMoveEvent(QMouseEvent * e)
{
    if (e->buttons() != Qt::LeftButton) {
        QWidget::mouseMoveEvent(e);
        return;
    }

    Q_D(QSizeGrip);
    QWidget* tlw = qt_sizegrip_topLevelWidget(this);
    if (!d->gotMousePress || tlw->testAttribute(Qt::WA_WState_ConfigPending))
        return;

#ifdef Q_WS_X11
    if (tlw->isWindow() && X11->isSupportedByWM(ATOM(_NET_WM_MOVERESIZE))
        && tlw->isTopLevel() && !tlw->testAttribute(Qt::WA_DontShowOnScreen) && !hasHeightForWidth(tlw))
        return;
#endif
#ifdef Q_WS_WIN
    if (tlw->isWindow() && GetSystemMenu(tlw->winId(), FALSE) != 0 && internalWinId()
        && !tlw->testAttribute(Qt::WA_DontShowOnScreen) && !hasHeightForWidth(tlw)) {
        MSG msg;
        while(PeekMessage(&msg, winId(), WM_MOUSEMOVE, WM_MOUSEMOVE, PM_REMOVE));
        return;
    }
#endif

    QPoint np(e->globalPos());

    // Don't extend beyond the available geometry; bound to dyMax and dxMax.
    QSize ns;
    if (d->atBottom())
        ns.rheight() = d->r.height() + qMin(np.y() - d->p.y(), d->dyMax);
    else
        ns.rheight() = d->r.height() - qMax(np.y() - d->p.y(), d->dyMax);

    if (d->atLeft())
        ns.rwidth() = d->r.width() - qMax(np.x() - d->p.x(), d->dxMax);
    else
        ns.rwidth() = d->r.width() + qMin(np.x() - d->p.x(), d->dxMax);

    ns = QLayout::closestAcceptableSize(tlw, ns);

    QPoint p;
    QRect nr(p, ns);
    if (d->atBottom()) {
        if (d->atLeft())
            nr.moveTopRight(d->r.topRight());
        else
            nr.moveTopLeft(d->r.topLeft());
    } else {
        if (d->atLeft())
            nr.moveBottomRight(d->r.bottomRight());
        else
            nr.moveBottomLeft(d->r.bottomLeft());
    }

    tlw->setGeometry(nr);
}

/*!
  \reimp
*/
void QSizeGrip::mouseReleaseEvent(QMouseEvent *mouseEvent)
{
    if (mouseEvent->button() == Qt::LeftButton) {
        Q_D(QSizeGrip);
        d->gotMousePress = false;
        d->p = QPoint();
    } else {
        QWidget::mouseReleaseEvent(mouseEvent);
    }
}

/*!
  \reimp
*/
void QSizeGrip::moveEvent(QMoveEvent * /*moveEvent*/)
{
    Q_D(QSizeGrip);
    // We're inside a resize operation; no update necessary.
    if (!d->p.isNull())
        return;

    d->m_corner = d->corner();
#if !defined(QT_NO_CURSOR) && !defined(Q_WS_MAC)
    setCursor(d->m_corner == Qt::TopLeftCorner || d->m_corner == Qt::BottomRightCorner
              ? Qt::SizeFDiagCursor : Qt::SizeBDiagCursor);
#endif
}

/*!
  \reimp
*/
void QSizeGrip::showEvent(QShowEvent *showEvent)
{
#ifdef Q_WS_MAC
    d_func()->updateMacSizer(false);
#endif
    QWidget::showEvent(showEvent);
}

/*!
  \reimp
*/
void QSizeGrip::hideEvent(QHideEvent *hideEvent)
{
#ifdef Q_WS_MAC
    d_func()->updateMacSizer(true);
#endif
    QWidget::hideEvent(hideEvent);
}

/*!
    \reimp
*/
void QSizeGrip::setVisible(bool visible)
{
    QWidget::setVisible(visible);
}

/*! \reimp */
bool QSizeGrip::eventFilter(QObject *o, QEvent *e)
{
    if ((isHidden() && testAttribute(Qt::WA_WState_ExplicitShowHide))
        || e->type() != QEvent::WindowStateChange) {
        return QWidget::eventFilter(o, e);
    }
    QWidget *tlw = qt_sizegrip_topLevelWidget(this);
    if (o != tlw)
        return QWidget::eventFilter(o, e);
    Qt::WindowStates sizeGripNotVisibleState = Qt::WindowFullScreen;
#ifndef Q_WS_MAC
    sizeGripNotVisibleState |= Qt::WindowMaximized;
#endif
    // Don't show the size grip if the tlw is maximized or in full screen mode.
    setVisible(!(tlw->windowState() & sizeGripNotVisibleState));
    setAttribute(Qt::WA_WState_ExplicitShowHide, false);
    return QWidget::eventFilter(o, e);
}

/*!
    \reimp
*/
bool QSizeGrip::event(QEvent *event)
{
    return QWidget::event(event);
}

#ifdef Q_WS_WIN
/*! \reimp */
bool QSizeGrip::winEvent( MSG *m, long *result )
{
    return QWidget::winEvent(m, result);
}
#endif

QT_END_NAMESPACE

#include "moc_qsizegrip.cpp"

#endif //QT_NO_SIZEGRIP