src/uisupport/treeviewtouch.cpp

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   2  *   Copyright (C) 2005-2018 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 (event->type() == QEvent::TouchBegin && ((QTouchEvent*)event)->device()->type()==QTouchDevice::TouchScreen) {
  37         // Register that we may be scrolling, set the scroll mode to scroll-per-pixel
  38         // and accept the event (return true) so that we will receive TouchUpdate and TouchEnd/TouchCancel
  39         _touchScrollInProgress = true;
  40         setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
  41         return true;
  42     }
  43
  44     if (event->type() == QEvent::TouchUpdate && _touchScrollInProgress) {
  45         QTouchEvent::TouchPoint p = ((QTouchEvent*)event)->touchPoints().at(0);
  46         if (!_firstTouchUpdateHappened) {
  47             // After the first movement of a Touch-Point, calculate the distance in both axis
  48             // and if the point moved more horizontally abort scroll.
  49             double dx = qAbs(p.lastPos().x() - p.pos().x());
  50             double dy = qAbs(p.lastPos().y() - p.pos().y());
  51             if (dx > dy) {
  52                 _touchScrollInProgress = false;
  53             }
  54             _firstTouchUpdateHappened = true;
  55         }
  56         // Apply touch movement to scrollbar
  57         verticalScrollBar()->setValue(verticalScrollBar()->value() - (p.pos().y() - p.lastPos().y()));
  58         return true;
  59     }
  60
  61     if (event->type() == QEvent::TouchEnd || event->type() == QEvent::TouchCancel) {
  62         // End scroll and reset variables
  63         _touchScrollInProgress = false;
  64         _firstTouchUpdateHappened = false;
  65         return true;
  66     }
  67
  68     return QTreeView::event(event);
  69 }
  70
  71
  72 void TreeViewTouch::mousePressEvent(QMouseEvent *event) {
  73     if (!_touchScrollInProgress)
  74         QTreeView::mousePressEvent(event);
  75 }
  76
  77
  78 void TreeViewTouch::mouseMoveEvent(QMouseEvent *event) {
  79     if (!_touchScrollInProgress)
  80         QTreeView::mouseMoveEvent(event);
  81 }