plugins/Ubuntu/Gestures/DirectionalDragArea.cpp · unity8

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unity8/plugins/Ubuntu/Gestures/DirectionalDragArea.cpp

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1/*

3 *

4 * This program is free software; you can redistribute it and/or modify

5 * it under the terms of the GNU General Public License as published by

6 * the Free Software Foundation; version 3.

7 *

8 * This program is distributed in the hope that it will be useful,

9 * but WITHOUT ANY WARRANTY; without even the implied warranty of

10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

11 * GNU General Public License for more details.

12 *

13 * You should have received a copy of the GNU General Public License

14 * along with this program. If not, see <http://www.gnu.org/licenses/>.

15 */

17#include "DirectionalDragArea.h"

19#include <QtCore/qmath.h>

20#include <QtCore/QTimer>

22// Essentially a QTimer wrapper

23class RecognitionTimer : public UbuntuGestures::AbstractTimer

24{

25 Q_OBJECT

26public:

27 RecognitionTimer(QObject *parent) : UbuntuGestures::AbstractTimer(parent) {

28 m_timer.setSingleShot(false);

29 connect(&m_timer, &QTimer::timeout,

30 this, &UbuntuGestures::AbstractTimer::timeout);

31 }

32 virtual int interval() const { return m_timer.interval(); }

33 virtual void setInterval(int msecs) { m_timer.setInterval(msecs); }

34 virtual void start() { m_timer.start(); UbuntuGestures::AbstractTimer::start(); }

35 virtual void stop() { m_timer.stop(); UbuntuGestures::AbstractTimer::stop(); }

36private:

37 QTimer m_timer;

38};

40DirectionalDragArea::DirectionalDragArea(QQuickItem *parent)

41 : QQuickItem(parent)

42 , m_status(WaitingForTouch)

43 , m_touchId(-1)

44 , m_direction(Direction::Rightwards)

45 , m_wideningAngle(0)

46 , m_wideningFactor(0)

47 , m_distanceThreshold(0)

48 , m_minSpeed(0)

49 , m_maxSilenceTime(200)

50 , m_silenceTime(0)

51 , m_numSamplesOnLastSpeedCheck(0)

52 , m_recognitionTimer(0)

53 , m_velocityCalculator(0)

54{

55 setRecognitionTimer(new RecognitionTimer(this));

56 m_recognitionTimer->setInterval(60);

58 m_velocityCalculator = new AxisVelocityCalculator(this);

59}

61Direction::Type DirectionalDragArea::direction() const

62{

63 return m_direction;

64}

66void DirectionalDragArea::setDirection(Direction::Type direction)

67{

68 if (direction != m_direction) {

69 m_direction = direction;

70 Q_EMIT directionChanged(m_direction);

71 }

72}

74void DirectionalDragArea::setMaxDeviation(qreal value)

75{

76 if (m_dampedPos.maxDelta() != value) {

77 m_dampedPos.setMaxDelta(value);

78 Q_EMIT maxDeviationChanged(value);

79 }

80}

82qreal DirectionalDragArea::wideningAngle() const

83{

84 return m_wideningAngle;

85}

87void DirectionalDragArea::setWideningAngle(qreal angle)

88{

89 if (angle == m_wideningAngle)

90 return;

92 m_wideningAngle = angle;

93 m_wideningFactor = qTan(angle * M_PI / 180.0);

94 Q_EMIT wideningAngleChanged(angle);

95}

97void DirectionalDragArea::setDistanceThreshold(qreal value)

98{

99 if (m_distanceThreshold != value) {

100 m_distanceThreshold = value;

101 Q_EMIT distanceThresholdChanged(value);

102 }

103}

104

105void DirectionalDragArea::setMinSpeed(qreal value)

106{

107 if (m_minSpeed != value) {

108 m_minSpeed = value;

109 Q_EMIT minSpeedChanged(value);

110 }

111}

112

113void DirectionalDragArea::setMaxSilenceTime(int value)

114{

115 if (m_maxSilenceTime != value) {

116 m_maxSilenceTime = value;

117 Q_EMIT maxSilenceTimeChanged(value);

118 }

119}

120

121void DirectionalDragArea::setRecognitionTimer(UbuntuGestures::AbstractTimer *timer)

122{

123 int interval = 0;

124 bool timerWasRunning = false;

125

126 // can be null when called from the constructor

127 if (m_recognitionTimer) {

128 interval = m_recognitionTimer->interval();

129 timerWasRunning = m_recognitionTimer->isRunning();

130 if (m_recognitionTimer->parent() == this) {

131 delete m_recognitionTimer;

132 }

133 }

134

135 m_recognitionTimer = timer;

136 timer->setInterval(interval);

137 connect(timer, &UbuntuGestures::AbstractTimer::timeout,

138 this, &DirectionalDragArea::checkSpeed);

139 if (timerWasRunning) {

140 m_recognitionTimer->start();

141 }

142}

143

144void DirectionalDragArea::setTimeSource(UbuntuGestures::TimeSource *timeSource)

145{

146 m_velocityCalculator->setTimeSource(timeSource);

147}

148

149qreal DirectionalDragArea::distance() const

150{

151 if (Direction::isHorizontal(m_direction)) {

152 return m_previousPos.x() - m_startPos.x();

153 } else {

154 return m_previousPos.y() - m_startPos.y();

155 }

156}

157

158qreal DirectionalDragArea::sceneDistance() const

159{

160 if (Direction::isHorizontal(m_direction)) {

161 return m_previousScenePos.x() - m_startScenePos.x();

162 } else {

163 return m_previousScenePos.y() - m_startScenePos.y();

164 }

165}

166

167qreal DirectionalDragArea::touchX() const

168{

169 return m_previousPos.x();

170}

171

172qreal DirectionalDragArea::touchY() const

173{

174 return m_previousPos.y();

175}

176

177qreal DirectionalDragArea::touchSceneX() const

178{

179 return m_previousScenePos.x();

180}

181

182qreal DirectionalDragArea::touchSceneY() const

183{

184 return m_previousScenePos.y();

185}

186

187void DirectionalDragArea::touchEvent(QTouchEvent *event)

188{

189 if (!isEnabled() || !isVisible()) {

190 QQuickItem::touchEvent(event);

191 return;

192 }

193

194 switch (m_status) {

195 case WaitingForTouch:

196 touchEvent_absent(event);

197 break;

198 case Undecided:

199 touchEvent_undecided(event);

200 break;

201 case Recognized:

202 touchEvent_recognized(event);

203 break;

204 default: // Rejected

205 touchEvent_rejected(event);

206 break;

207 }

208}

209

210void DirectionalDragArea::touchEvent_absent(QTouchEvent *event)

211{

212 if ((event->touchPointStates() && (Qt::TouchPointPressed || Qt::TouchPointMoved))

213 && event->touchPoints().count() == 1) {

214 const QTouchEvent::TouchPoint &touchPoint = event->touchPoints()[0];

215 m_startPos = touchPoint.pos();

216 m_startScenePos = touchPoint.scenePos();

217 m_touchId = touchPoint.id();

218 m_dampedPos.reset(m_startPos);

219 updateVelocityCalculator(m_startPos);

220 m_velocityCalculator->reset();

221 m_numSamplesOnLastSpeedCheck = 0;

222 m_silenceTime = 0;

223 setPreviousPos(m_startPos);

224 setPreviousScenePos(m_startScenePos);

225

226 if (m_distanceThreshold > 0)

227 setStatus(Undecided);

228 else

229 setStatus(Recognized);

230 }

231}

232

233void DirectionalDragArea::touchEvent_undecided(QTouchEvent *event)

234{

235 const QTouchEvent::TouchPoint *touchPoint = fetchTargetTouchPoint(event);

236 const QPointF &touchPos = touchPoint->pos();

237

238 if (touchPoint->state() == Qt::TouchPointReleased) {

239 // touch has ended before recognition concluded

240 setStatus(WaitingForTouch);

241 return;

242 }

243

244 if (event->touchPointStates().testFlag(Qt::TouchPointPressed)

245 || event->touchPoints().count() > 1) {

246 // multi-finger drags are not accepted

247 setStatus(Rejected);

248 return;

249 }

250

251 m_previousDampedPos.setX(m_dampedPos.x());

252 m_previousDampedPos.setY(m_dampedPos.y());

253 m_dampedPos.update(touchPos);

254 updateVelocityCalculator(touchPos);

255

256 if (!pointInsideAllowedArea()) {

257 setStatus(Rejected);

258 return;

259 }

260

261 if (!movingInRightDirection()) {

262 setStatus(Rejected);

263 return;

264 }

265

266 setPreviousPos(touchPos);

267 setPreviousScenePos(touchPoint->scenePos());

268

269 if (movedFarEnough(touchPos)) {

270 setStatus(Recognized);

271 }

272}

273

274void DirectionalDragArea::touchEvent_recognized(QTouchEvent *event)

275{

276 const QTouchEvent::TouchPoint *touchPoint = fetchTargetTouchPoint(event);

277

278 setPreviousPos(touchPoint->pos());

279 setPreviousScenePos(touchPoint->scenePos());

280

281 if (touchPoint->state() == Qt::TouchPointReleased) {

282 setStatus(WaitingForTouch);

283 }

284}

285

286void DirectionalDragArea::touchEvent_rejected(QTouchEvent *event)

287{

288 const QTouchEvent::TouchPoint *touchPoint = fetchTargetTouchPoint(event);

289

290 if (!touchPoint || touchPoint->state() == Qt::TouchPointReleased) {

291 setStatus(WaitingForTouch);

292 }

293}

294

295const QTouchEvent::TouchPoint *DirectionalDragArea::fetchTargetTouchPoint(QTouchEvent *event)

296{

297 const QList<QTouchEvent::TouchPoint> &touchPoints = event->touchPoints();

298 const QTouchEvent::TouchPoint *touchPoint = 0;

299 for (int i = 0; i < touchPoints.size(); ++i) {

300 if (touchPoints.at(i).id() == m_touchId) {

301 touchPoint = &touchPoints.at(i);

302 break;

303 }

304 }

305 return touchPoint;

306}

307

308bool DirectionalDragArea::pointInsideAllowedArea() const

309{

310 qreal dX = m_dampedPos.x() - m_startPos.x();

311 qreal dY = m_dampedPos.y() - m_startPos.y();

312

313 switch (m_direction) {

314 case Direction::Upwards:

315 return dY <= 0 && qFabs(dX) <= qFabs(dY) * m_wideningFactor;

316 case Direction::Downwards:

317 return dY >= 0 && qFabs(dX) <= dY * m_wideningFactor;

318 case Direction::Leftwards:

319 return dX <= 0 && qFabs(dY) <= qFabs(dX) * m_wideningFactor;

320 default: // Direction::Rightwards:

321 return dX >= 0 && qFabs(dY) <= dX * m_wideningFactor;

322 }

323}

324

325bool DirectionalDragArea::movingInRightDirection() const

326{

327 switch (m_direction) {

328 case Direction::Upwards:

329 return m_dampedPos.y() <= m_previousDampedPos.y();

330 case Direction::Downwards:

331 return m_dampedPos.y() >= m_previousDampedPos.y();

332 case Direction::Leftwards:

333 return m_dampedPos.x() <= m_previousDampedPos.x();

334 default: // Direction::Rightwards:

335 return m_dampedPos.x() >= m_previousDampedPos.x();

336 }

337}

338

339bool DirectionalDragArea::movedFarEnough(const QPointF &point) const

340{

341 if (Direction::isHorizontal(m_direction))

342 return qFabs(point.x() - m_startPos.x()) > m_distanceThreshold;

343 else

344 return qFabs(point.y() - m_startPos.y()) > m_distanceThreshold;

345}

346

347void DirectionalDragArea::checkSpeed()

348{

349 if (m_velocityCalculator->numSamples() >= AxisVelocityCalculator::MIN_SAMPLES_NEEDED) {

350 qreal speed = qFabs(m_velocityCalculator->calculate());

351 qreal minSpeedMsecs = m_minSpeed / 1000.0;

352

353 if (speed < minSpeedMsecs) {

354 setStatus(Rejected);

355 }

356 }

357

358 if (m_velocityCalculator->numSamples() == m_numSamplesOnLastSpeedCheck) {

359 m_silenceTime += m_recognitionTimer->interval();

360

361 if (m_silenceTime > m_maxSilenceTime) {

362 setStatus(Rejected);

363 }

364 } else {

365 m_silenceTime = 0;

366 }

367 m_numSamplesOnLastSpeedCheck = m_velocityCalculator->numSamples();

368}

369

370void DirectionalDragArea::setStatus(DirectionalDragArea::Status newStatus)

371{

372 if (newStatus == m_status)

373 return;

374

375 DirectionalDragArea::Status oldStatus = m_status;

376

377 if (oldStatus == Undecided) {

378 m_recognitionTimer->stop();

379 }

380

381 m_status = newStatus;

382 Q_EMIT statusChanged(m_status);

383

384 switch (newStatus) {

385 case WaitingForTouch:

386 if (oldStatus != DirectionalDragArea::Rejected) {

387 Q_EMIT draggingChanged(false);

388 }

389 break;

390 case Undecided:

391 m_recognitionTimer->start();

392 Q_EMIT draggingChanged(true);

393 break;

394 case Recognized:

395 if (oldStatus == WaitingForTouch)

396 Q_EMIT draggingChanged(true);

397 break;

398 case Rejected:

399 Q_EMIT draggingChanged(false);

400 break;

401 default:

402 // no-op

403 break;

404 }

405}

406

407void DirectionalDragArea::setPreviousPos(const QPointF &point)

408{

409 Q_ASSERT(m_status != Rejected);

410

411 bool xChanged = m_previousPos.x() != point.x();

412 bool yChanged = m_previousPos.y() != point.y();

413

414 m_previousPos = point;

415

416 if (xChanged) {

417 Q_EMIT touchXChanged(point.x());

418 if (Direction::isHorizontal(m_direction))

419 Q_EMIT distanceChanged(distance());

420 }

421

422 if (yChanged) {

423 Q_EMIT touchYChanged(point.y());

424 if (Direction::isVertical(m_direction))

425 Q_EMIT distanceChanged(distance());

426 }

427}

428

429void DirectionalDragArea::setPreviousScenePos(const QPointF &point)

430{

431 Q_ASSERT(m_status != Rejected);

432

433 bool xChanged = m_previousScenePos.x() != point.x();

434 bool yChanged = m_previousScenePos.y() != point.y();

435

436 m_previousScenePos = point;

437

438 if (xChanged) {

439 Q_EMIT touchSceneXChanged(point.x());

440 if (Direction::isHorizontal(m_direction))

441 Q_EMIT sceneDistanceChanged(sceneDistance());

442 }

443

444 if (yChanged) {

445 Q_EMIT touchSceneYChanged(point.y());

446 if (Direction::isVertical(m_direction))

447 Q_EMIT sceneDistanceChanged(sceneDistance());

448 }

449}

450

451void DirectionalDragArea::updateVelocityCalculator(const QPointF &point)

452{

453 if (Direction::isHorizontal(m_direction)) {

454 m_velocityCalculator->setTrackedPosition(point.x());

455 } else {

456 m_velocityCalculator->setTrackedPosition(point.y());

457 }

458}

459

460// Because we are defining a new QObject-based class (RecognitionTimer) here.

461#include "DirectionalDragArea.moc"