Differential D13901 Diff 54003 lib/touch/twofingertap.cpp

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lib/touch/twofingertap.cpp

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1		/*
2		Gwenview: an image viewer
3		Copyright 2019 Steffen Hartleib <steffenhartleib@t-online.de>
4
	ngrahamUnsubmitted Not Done Your copyright ngraham: Your copyright
5		This program is free software; you can redistribute it and/or
6		modify it under the terms of the GNU General Public License
7		as published by the Free Software Foundation; either version 2
8		of the License, or (at your option) any later version.
9
10		This program is distributed in the hope that it will be useful,
11		but WITHOUT ANY WARRANTY; without even the implied warranty of
12		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13		GNU General Public License for more details.
14
15		You should have received a copy of the GNU General Public License
16		along with this program; if not, write to the Free Software
17		Foundation, Inc., 51 Franklin Street, Fifth Floor, Cambridge, MA 02110-1301, USA.
18
19		*/
20		// Self
21		#include "twofingertap.h"
22
23		// Qt
24		#include <QTouchEvent>
25		#include <QDebug>
26		#include <QGraphicsWidget>
27
28		// KDE
29
30		// Local
31		#include "lib/touch/touch_helper.h"
32
33		namespace Gwenview
34		{
35
36		struct TwoFingerTapRecognizerPrivate
37		{
38		TwoFingerTapRecognizer* q;
39		bool mTargetIsGrapicsWidget = false;
40		qint64 mTouchBeginnTimestamp;
41		bool mGestureTriggered;
42		};
43
44		TwoFingerTapRecognizer::TwoFingerTapRecognizer() : QGestureRecognizer()
45		, d (new TwoFingerTapRecognizerPrivate)
46		{
47		d->q = this;
48		}
49
50		TwoFingerTapRecognizer::~TwoFingerTapRecognizer()
51		{
52		delete d;
53		}
54
55		QGesture* TwoFingerTapRecognizer::create(QObject*)
56		{
57		return static_cast<QGesture*>(new TwoFingerTap());
58		}
59
60		QGestureRecognizer::Result TwoFingerTapRecognizer::recognize(QGesture* state, QObject* watched, QEvent* event)
61		{
62		//Because of a bug in Qt in a gesture event in a graphicsview, all gestures are trigger twice
63		//https://bugreports.qt.io/browse/QTBUG-13103
64		if (qobject_cast<QGraphicsWidget*>(watched)) d->mTargetIsGrapicsWidget = true;
65		if (d->mTargetIsGrapicsWidget && watched->isWidgetType()) return Ignore;
66
67
68		switch (event->type()) {
69		case QEvent::TouchBegin: {
70		QTouchEvent* touchEvent = static_cast<QTouchEvent*>(event);
71		d->mTouchBeginnTimestamp = touchEvent->timestamp();
72		state->setHotSpot(touchEvent->touchPoints().first().screenPos());
73		d->mGestureTriggered = false;
74		return MayBeGesture;
75		}
76
77		case QEvent::TouchUpdate: {
78		QTouchEvent* touchEvent = static_cast<QTouchEvent*>(event);
79		state->setHotSpot(touchEvent->touchPoints().first().screenPos());
80
81		if (touchEvent->touchPoints().size() >> 2) {
82		d->mGestureTriggered = false;
83		return CancelGesture;
84		}
85
86		if (touchEvent->touchPoints().size() == 2) {
87		if ((touchEvent->touchPoints().first().startPos() - touchEvent->touchPoints().first().pos()).manhattanLength() > Touch_Helper::Touch::wiggleRoomForTap) {
88		d->mGestureTriggered = false;
89		return CancelGesture;
90		}
91		if ((touchEvent->touchPoints().at(1).startPos() - touchEvent->touchPoints().at(1).pos()).manhattanLength() > Touch_Helper::Touch::wiggleRoomForTap) {
92		d->mGestureTriggered = false;
93		return CancelGesture;
94		}
95		if (touchEvent->touchPointStates() & Qt::TouchPointPressed) {
96		d->mGestureTriggered = true;
97		}
98		if (touchEvent->touchPointStates() & Qt::TouchPointReleased && d->mGestureTriggered) {
99		d->mGestureTriggered = false;
100		return FinishGesture;
101		}
102		}
103		break;
104		}
105
106		default:
107		return Ignore;
108		}
109		return Ignore;
110		}
111
112		TwoFingerTap::TwoFingerTap(QObject* parent)
113		: QGesture(parent)
114		{
115		}
116
117		} // namespace