Unity 8
PanelVelocityCalculator.qml
1 /*
2  * Copyright (C) 2014 Canonical, Ltd.
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  */
16 
17 import QtQuick 2.4
18 import Ubuntu.Gestures 0.1
19 
20 Item {
21  id: root
22  property real trackedValue: 0
23  property bool velocityAboveThreshold: false
24  property real velocityThreshold: 0.4
25 
26  function reset() {
27  velocityTimer.stop();
28  velocityAboveThreshold = false;
29  calc.reset();
30  }
31 
32  function update() {
33  calc.trackedPosition = trackedValue;
34  velocityAboveThreshold = Math.abs(calc.calculate()) > velocityThreshold;
35 
36  if (velocityAboveThreshold) { // only start timer if we're above the threshold.
37  velocityTimer.start();
38  } else {
39  velocityTimer.stop();
40  }
41  }
42 
43  onTrackedValueChanged: update();
44 
45  AxisVelocityCalculator {
46  id: calc
47  }
48 
49  Timer {
50  id: velocityTimer
51  interval: 50
52  onTriggered: update();
53  }
54 }