Differential D13901 Diff 54003 lib/touch/oneandtwofingerswipe.cpp

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lib/touch/oneandtwofingerswipe.cpp

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1		/*
2		Gwenview: an image viewer
	ngrahamUnsubmitted Not Done Please remove ngraham: Please remove
3		Copyright 2019 Steffen Hartleib <steffenhartleib@t-online.de>
4
5		This program is free software; you can redistribute it and/or
	ngrahamUnsubmitted Not Done Your copyright ngraham: Your copyright
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 "oneandtwofingerswipe.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 OneAndTwoFingerSwipeRecognizerPrivate
37		{
38		OneAndTwoFingerSwipeRecognizer* q;
39		bool mTargetIsGrapicsWidget = false;
40		qint64 mTouchBeginnTimestamp;
41		bool mGestureAlreadyTriggered;
42		};
43
44		OneAndTwoFingerSwipeRecognizer::OneAndTwoFingerSwipeRecognizer() : QGestureRecognizer()
45		, d (new OneAndTwoFingerSwipeRecognizerPrivate)
46		{
47		d->q = this;
48		}
49
50		OneAndTwoFingerSwipeRecognizer::~OneAndTwoFingerSwipeRecognizer()
51		{
52		delete d;
53		}
54
55		QGesture* OneAndTwoFingerSwipeRecognizer::create(QObject*)
56		{
57		return static_cast<QGesture*>(new OneAndTwoFingerSwipe());
58		}
59
60		QGestureRecognizer::Result OneAndTwoFingerSwipeRecognizer::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		switch (event->type()) {
68		case QEvent::TouchBegin: {
69		QTouchEvent* touchEvent = static_cast<QTouchEvent*>(event);
70		d->mTouchBeginnTimestamp = touchEvent->timestamp();
71		d->mGestureAlreadyTriggered = false;
72		state->setHotSpot(touchEvent->touchPoints().first().screenPos());
73		return MayBeGesture;
74		}
75
76		case QEvent::TouchUpdate: {
77		QTouchEvent* touchEvent = static_cast<QTouchEvent*>(event);
78		const qint64 now = touchEvent->timestamp();
79		const QPointF distance = touchEvent->touchPoints().first().startPos() - touchEvent->touchPoints().first().pos();
80		state->setHotSpot(touchEvent->touchPoints().first().screenPos());
81
82		if (touchEvent->touchPoints().size() >> 2) {
83		d->mGestureAlreadyTriggered = false;
84		return CancelGesture;
85		}
86
87		if (distance.manhattanLength() >= Touch_Helper::Touch::minDistanceForSwipe &&
88		(now - d->mTouchBeginnTimestamp) <= Touch_Helper::Touch::maxTimeFrameForSwipe &&
89		!d->mGestureAlreadyTriggered) {
90		if (distance.x() < 0 && abs(distance.x()) >= abs(distance.y()) * 2) {
91		state->setProperty("right", true);
92		state->setProperty("left", false);
93		d->mGestureAlreadyTriggered = true;
94		return FinishGesture;
95		}
96		if (distance.x() > 0 && abs(distance.x()) >= abs(distance.y()) * 2) {
97		state->setProperty("right", false);
98		state->setProperty("left", true);
99		d->mGestureAlreadyTriggered = true;
100		return FinishGesture;
101		}
102		if ((now - d->mTouchBeginnTimestamp) <= Touch_Helper::Touch::maxTimeFrameForSwipe && !d->mGestureAlreadyTriggered) {
103		return MayBeGesture;
104		} else {
105		d->mGestureAlreadyTriggered = false;
106		return CancelGesture;
107		}
108		}
109		break;
110		}
111
112		default:
113		return Ignore;
114		}
115		return Ignore;
116		}
117
118		OneAndTwoFingerSwipe::OneAndTwoFingerSwipe(QObject* parent)
119		: QGesture(parent)
120		{
121		}
122
123		} // namespace