summaryrefslogtreecommitdiffstats
path: root/src/gui/kernel/qsimpledrag.cpp
blob: 1fba6493549f81c5fbd16de3dcdb065598bcafdd (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
/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** 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
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** 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-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qsimpledrag_p.h"

#include "qbitmap.h"
#include "qdrag.h"
#include "qpixmap.h"
#include "qevent.h"
#include "qfile.h"
#include "qtextcodec.h"
#include "qguiapplication.h"
#include "qpoint.h"
#include "qbuffer.h"
#include "qimage.h"
#include "qregexp.h"
#include "qdir.h"
#include "qimagereader.h"
#include "qimagewriter.h"
#include "qplatformscreen.h"
#include "qplatformwindow.h"

#include <QtCore/QEventLoop>
#include <QtCore/QDebug>

#include <private/qguiapplication_p.h>
#include <private/qdnd_p.h>

#include <private/qshapedpixmapdndwindow_p.h>
#include <private/qhighdpiscaling_p.h>

QT_BEGIN_NAMESPACE

#ifndef QT_NO_DRAGANDDROP

static QWindow* topLevelAt(const QPoint &pos)
{
    QWindowList list = QGuiApplication::topLevelWindows();
    for (int i = list.count()-1; i >= 0; --i) {
        QWindow *w = list.at(i);
        if (w->isVisible() && w->geometry().contains(pos) && !qobject_cast<QShapedPixmapWindow*>(w))
            return w;
    }
    return 0;
}

/*!
    \class QBasicDrag
    \brief QBasicDrag is a base class for implementing platform drag and drop.
    \since 5.0
    \internal
    \ingroup qpa

    QBasicDrag implements QPlatformDrag::drag() by running a local event loop in which
    it tracks mouse movements and moves the drag icon (QShapedPixmapWindow) accordingly.
    It provides new virtuals allowing for querying whether the receiving window
    (within the Qt application or outside) accepts the drag and sets the state accordingly.
*/

QBasicDrag::QBasicDrag() :
    m_restoreCursor(false), m_eventLoop(0),
    m_executed_drop_action(Qt::IgnoreAction), m_can_drop(false),
    m_drag(0), m_drag_icon_window(0), m_useCompositing(true),
    m_screen(nullptr)
{
}

QBasicDrag::~QBasicDrag()
{
    delete m_drag_icon_window;
}

void QBasicDrag::enableEventFilter()
{
    qApp->installEventFilter(this);
}

void QBasicDrag::disableEventFilter()
{
    qApp->removeEventFilter(this);
}


static inline QPoint getNativeMousePos(QEvent *e, QObject *o)
{
    return QHighDpi::toNativePixels(static_cast<QMouseEvent *>(e)->globalPos(), qobject_cast<QWindow*>(o));
}

bool QBasicDrag::eventFilter(QObject *o, QEvent *e)
{
    Q_UNUSED(o);

    if (!m_drag) {
        if (e->type() == QEvent::KeyRelease && static_cast<QKeyEvent*>(e)->key() == Qt::Key_Escape) {
            disableEventFilter();
            exitDndEventLoop();
            return true; // block the key release
        }
        return false;
    }

    switch (e->type()) {
        case QEvent::ShortcutOverride:
            // prevent accelerators from firing while dragging
            e->accept();
            return true;

        case QEvent::KeyPress:
        case QEvent::KeyRelease:
        {
            QKeyEvent *ke = static_cast<QKeyEvent *>(e);
            if (ke->key() == Qt::Key_Escape && e->type() == QEvent::KeyPress) {
                cancel();
                disableEventFilter();
                exitDndEventLoop();

            }
            return true; // Eat all key events
        }

        case QEvent::MouseMove:
        {
            QPoint nativePosition = getNativeMousePos(e, o);
            move(nativePosition);
            return true; // Eat all mouse move events
        }
        case QEvent::MouseButtonRelease:
            disableEventFilter();
            if (canDrop()) {
                QPoint nativePosition = getNativeMousePos(e, o);
                drop(nativePosition);
            } else {
                cancel();
            }
            exitDndEventLoop();
            QCoreApplication::postEvent(o, new QMouseEvent(*static_cast<QMouseEvent *>(e)));
            return true; // defer mouse release events until drag event loop has returned
        case QEvent::MouseButtonDblClick:
        case QEvent::Wheel:
            return true;
        default:
             break;
    }
    return false;
}

Qt::DropAction QBasicDrag::drag(QDrag *o)
{
    m_drag = o;
    m_executed_drop_action = Qt::IgnoreAction;
    m_can_drop = false;
    m_restoreCursor = true;
#ifndef QT_NO_CURSOR
    qApp->setOverrideCursor(Qt::DragCopyCursor);
    updateCursor(m_executed_drop_action);
#endif
    startDrag();
    m_eventLoop = new QEventLoop;
    m_eventLoop->exec();
    delete m_eventLoop;
    m_eventLoop = 0;
    m_drag = 0;
    endDrag();
    return m_executed_drop_action;
}

void QBasicDrag::cancelDrag()
{
    if (m_eventLoop) {
        cancel();
        m_eventLoop->quit();
    }
}

void QBasicDrag::restoreCursor()
{
    if (m_restoreCursor) {
#ifndef QT_NO_CURSOR
        QGuiApplication::restoreOverrideCursor();
#endif
        m_restoreCursor = false;
    }
}

void QBasicDrag::startDrag()
{
    QPoint pos;
#ifndef QT_NO_CURSOR
    pos = QCursor::pos();
    if (pos.x() == int(qInf())) {
        // ### fixme: no mouse pos registered. Get pos from touch...
        pos = QPoint();
    }
#endif
    recreateShapedPixmapWindow(m_screen, pos);
    enableEventFilter();
}

void QBasicDrag::endDrag()
{
}

void QBasicDrag::recreateShapedPixmapWindow(QScreen *screen, const QPoint &pos)
{
    delete m_drag_icon_window;
    // ### TODO Check if its really necessary to have m_drag_icon_window
    // when QDrag is used without a pixmap - QDrag::setPixmap()
    m_drag_icon_window = new QShapedPixmapWindow(screen);

    m_drag_icon_window->setUseCompositing(m_useCompositing);
    m_drag_icon_window->setPixmap(m_drag->pixmap());
    m_drag_icon_window->setHotspot(m_drag->hotSpot());
    m_drag_icon_window->updateGeometry(pos);
    m_drag_icon_window->setVisible(true);
}

void QBasicDrag::cancel()
{
    disableEventFilter();
    restoreCursor();
    m_drag_icon_window->setVisible(false);
}

/*!
  Move the drag label to \a globalPos, which is
  interpreted in device independent coordinates. Typically called from reimplementations of move().
 */

void QBasicDrag::moveShapedPixmapWindow(const QPoint &globalPos)
{
    if (m_drag)
        m_drag_icon_window->updateGeometry(globalPos);
}

void QBasicDrag::drop(const QPoint &)
{
    disableEventFilter();
    restoreCursor();
    m_drag_icon_window->setVisible(false);
}

void  QBasicDrag::exitDndEventLoop()
{
    if (m_eventLoop && m_eventLoop->isRunning())
        m_eventLoop->exit();
}

void QBasicDrag::updateCursor(Qt::DropAction action)
{
#ifndef QT_NO_CURSOR
    Qt::CursorShape cursorShape = Qt::ForbiddenCursor;
    if (canDrop()) {
        switch (action) {
        case Qt::CopyAction:
            cursorShape = Qt::DragCopyCursor;
            break;
        case Qt::LinkAction:
            cursorShape = Qt::DragLinkCursor;
            break;
        default:
            cursorShape = Qt::DragMoveCursor;
            break;
        }
    }

    QCursor *cursor = QGuiApplication::overrideCursor();
    QPixmap pixmap = m_drag->dragCursor(action);
    if (!cursor) {
        QGuiApplication::changeOverrideCursor((pixmap.isNull()) ? QCursor(cursorShape) : QCursor(pixmap));
    } else {
        if (!pixmap.isNull()) {
            if ((cursor->pixmap().cacheKey() != pixmap.cacheKey())) {
                QGuiApplication::changeOverrideCursor(QCursor(pixmap));
            }
        } else {
            if (cursorShape != cursor->shape()) {
                QGuiApplication::changeOverrideCursor(QCursor(cursorShape));
            }
        }
    }
#endif
    updateAction(action);
}


static inline QPoint fromNativeGlobalPixels(const QPoint &point)
{
#ifndef QT_NO_HIGHDPISCALING
    QPoint res = point;
    if (QHighDpiScaling::isActive()) {
        for (const QScreen *s : qAsConst(QGuiApplicationPrivate::screen_list)) {
            if (s->handle()->geometry().contains(point)) {
                res = QHighDpi::fromNativePixels(point, s);
                break;
            }
        }
    }
    return res;
#else
    return point;
#endif
}

/*!
    \class QSimpleDrag
    \brief QSimpleDrag implements QBasicDrag for Drag and Drop operations within the Qt Application itself.
    \since 5.0
    \internal
    \ingroup qpa

    The class checks whether the receiving window is a window of the Qt application
    and sets the state accordingly. It does not take windows of other applications
    into account.
*/

QSimpleDrag::QSimpleDrag() : m_current_window(0)
{
}

void QSimpleDrag::startDrag()
{
    QBasicDrag::startDrag();
    m_current_window = topLevelAt(QCursor::pos());
    if (m_current_window) {
        QPlatformDragQtResponse response = QWindowSystemInterface::handleDrag(m_current_window, drag()->mimeData(), QHighDpi::toNativePixels(QCursor::pos(), m_current_window), drag()->supportedActions());
        setCanDrop(response.isAccepted());
        updateCursor(response.acceptedAction());
    } else {
        setCanDrop(false);
        updateCursor(Qt::IgnoreAction);
    }
    setExecutedDropAction(Qt::IgnoreAction);
}

void QSimpleDrag::cancel()
{
    QBasicDrag::cancel();
    if (drag() && m_current_window) {
        QWindowSystemInterface::handleDrag(m_current_window, 0, QPoint(), Qt::IgnoreAction);
        m_current_window = 0;
    }
}

void QSimpleDrag::move(const QPoint &nativeGlobalPos)
{
    QPoint globalPos = fromNativeGlobalPixels(nativeGlobalPos);
    moveShapedPixmapWindow(globalPos);
    QWindow *window = topLevelAt(globalPos);
    if (!window)
        return;

    const QPoint pos = nativeGlobalPos - window->handle()->geometry().topLeft();
    const QPlatformDragQtResponse qt_response =
        QWindowSystemInterface::handleDrag(window, drag()->mimeData(), pos, drag()->supportedActions());

    updateCursor(qt_response.acceptedAction());
    setCanDrop(qt_response.isAccepted());
}

void QSimpleDrag::drop(const QPoint &nativeGlobalPos)
{
    QPoint globalPos = fromNativeGlobalPixels(nativeGlobalPos);

    QBasicDrag::drop(nativeGlobalPos);
    QWindow *window = topLevelAt(globalPos);
    if (!window)
        return;

    const QPoint pos = nativeGlobalPos - window->handle()->geometry().topLeft();
    const QPlatformDropQtResponse response =
            QWindowSystemInterface::handleDrop(window, drag()->mimeData(),pos, drag()->supportedActions());
    if (response.isAccepted()) {
        setExecutedDropAction(response.acceptedAction());
    } else {
        setExecutedDropAction(Qt::IgnoreAction);
    }
}

#endif // QT_NO_DRAGANDDROP

QT_END_NAMESPACE