2 * Copyright (C) 2013 Canonical Ltd.
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.
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.
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/>.
18import Lomiri.Components 1.3
23 property int orientation: Qt.Vertical
24 property bool dragging
25 property real dragVelocity: 0
26 property real dragValue: (orientation == Qt.Vertical ? (mouseY - __pressedPosition.y)
27 : (mouseX - __pressedPosition.x))
28 property real lateralPosition: orientation == Qt.Horizontal ? MathUtils.clamp(mouseY, 0, height) : MathUtils.clamp(mouseX, 0, width)
29 property point __pressedPosition: Qt.point(0, 0)
30 property var __dragEvents: []
31 property bool clickValidated: true
32 property bool zeroVelocityCounts: false
34 // Can be replaced with a fake implementation during tests
35 // property var __getCurrentTimeMs: function () { return new Date().getTime() }
36 property var __dateTime: new function() {
37 this.getCurrentTimeMs = function() {return new Date().getTime()}
45 if (dragValue != 0 && pressed) {
59 function updateSpeed() {
61 for (var i=0; i<__dragEvents.length; i++) {
62 totalSpeed += __dragEvents[i][3]
65 if (zeroVelocityCounts || Math.abs(totalSpeed) > 0.001) {
66 dragVelocity = totalSpeed / __dragEvents.length * 1000
70 function cullOldDragEvents(currentTime) {
71 // cull events older than 50 ms but always keep the latest 2 events
72 for (var numberOfCulledEvents=0; numberOfCulledEvents<__dragEvents.length-2; numberOfCulledEvents++) {
73 // __dragEvents[numberOfCulledEvents][0] is the dragTime
74 if (currentTime - __dragEvents[numberOfCulledEvents][0] <= 50) break
77 __dragEvents.splice(0, numberOfCulledEvents)
80 function getEventSpeed(currentTime, event) {
81 if (__dragEvents.length != 0) {
82 var lastDrag = __dragEvents[__dragEvents.length-1]
83 var duration = Math.max(1, currentTime - lastDrag[0])
84 if (orientation == Qt.Vertical) {
85 return (event.y - lastDrag[2]) / duration
87 return (event.x - lastDrag[1]) / duration
94 function pushDragEvent(event) {
95 var currentTime = __dateTime.getCurrentTimeMs()
96 __dragEvents.push([currentTime, event.x, event.y, getEventSpeed(currentTime, event)])
97 cullOldDragEvents(currentTime)
105 if (!draggingArea.containsMouse)
106 clickValidated = false
110 __pressedPosition = Qt.point(mouse.x, mouse.y)
113 clickValidated = true
118 __pressedPosition = Qt.point(mouse.x, mouse.y)