src/uisupport/treeviewtouch.cpp

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   2  *   Copyright (C) 2005-2019 by the Quassel Project                        *
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  20
  21 #include "treeviewtouch.h"
  22
  23 #include <QEvent>
  24 #include <QScrollBar>
  25 #include <QTouchEvent>
  26
  27
  28 TreeViewTouch::TreeViewTouch(QWidget *parent)
  29     : QTreeView(parent)
  30 {
  31     setAttribute(Qt::WA_AcceptTouchEvents);
  32 }
  33
  34
  35 bool TreeViewTouch::event(QEvent *event) {
  36 #if QT_VERSION >= 0x050000
  37     if (event->type() == QEvent::TouchBegin && ((QTouchEvent*)event)->device()->type()==QTouchDevice::TouchScreen) {
  38 #else
  39     if (event->type() == QEvent::TouchBegin && ((QTouchEvent*)event)->deviceType()==QTouchEvent::TouchScreen) {
  40 #endif
  41         // Register that we may be scrolling, set the scroll mode to scroll-per-pixel
  42         // and accept the event (return true) so that we will receive TouchUpdate and TouchEnd/TouchCancel
  43         _touchScrollInProgress = true;
  44         setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
  45         return true;
  46     }
  47
  48     if (event->type() == QEvent::TouchUpdate && _touchScrollInProgress) {
  49         QTouchEvent::TouchPoint p = ((QTouchEvent*)event)->touchPoints().at(0);
  50         if (!_firstTouchUpdateHappened) {
  51             // After the first movement of a Touch-Point, calculate the distance in both axis
  52             // and if the point moved more horizontally abort scroll.
  53             double dx = qAbs(p.lastPos().x() - p.pos().x());
  54             double dy = qAbs(p.lastPos().y() - p.pos().y());
  55             if (dx > dy) {
  56                 _touchScrollInProgress = false;
  57             }
  58             _firstTouchUpdateHappened = true;
  59         }
  60         // Apply touch movement to scrollbar
  61         verticalScrollBar()->setValue(verticalScrollBar()->value() - (p.pos().y() - p.lastPos().y()));
  62         return true;
  63     }
  64
  65 #if QT_VERSION >= 0x050000
  66     if (event->type() == QEvent::TouchEnd || event->type() == QEvent::TouchCancel) {
  67 #else
  68     if (event->type() == QEvent::TouchEnd) {
  69 #endif
  70         // End scroll and reset variables
  71         _touchScrollInProgress = false;
  72         _firstTouchUpdateHappened = false;
  73         return true;
  74     }
  75
  76     return QTreeView::event(event);
  77 }
  78
  79
  80 void TreeViewTouch::mousePressEvent(QMouseEvent *event) {
  81     if (!_touchScrollInProgress)
  82         QTreeView::mousePressEvent(event);
  83 }
  84
  85
  86 void TreeViewTouch::mouseMoveEvent(QMouseEvent *event) {
  87     if (!_touchScrollInProgress)
  88         QTreeView::mouseMoveEvent(event);
  89 };