commit 06c92cf8ff1fa6c72d20579d54eb75b5fc9d25e6
author Jan-Marek Glogowski <glogow@fbihome.de> Thu Jun 06 01:01:11 2019 +0000
committer Jan-Marek Glogowski <glogow@fbihome.de> Fri Jun 07 03:08:26 2019 +0200
tree 3373302fba34734ccf4a64d78c2b9d14a55ab67f
parent 94adb80e6d5ec9d6c6b149ca98755d3a5a86531a

tdf#125201 fix QWheelEvent angleDelta() handling

Comming back to my initial, known broken implementation from
2017-11 (see commit 1426437be053 ("QT5 implement some mouse
handling")), which just works with mouse scroll wheels.

This just fixes angleDelta() based scrolling. An additional
patch might be needed, if some driver just uses pixelDelta()
values, but Qt explicitly states: "On X11 the pixelDelta()
value is driver specific and unreliable, use angleDelta()
instead.", so we'll do just that for now.

Change-Id: I1be5f9392ed475aea7ab4d965a07e1e3c2574fe7
Reviewed-on: https://gerrit.libreoffice.org/73614
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>
(cherry picked from commit 1d959beba1cfef5fde035a4a74ee4611e7a04869)
Reviewed-on: https://gerrit.libreoffice.org/73622

vcl/inc/qt5/Qt5Widget.hxx

diff --git a/vcl/inc/qt5/Qt5Widget.hxx b/vcl/inc/qt5/Qt5Widget.hxx
index 6398fa7..ce4e068 100644
--- a/vcl/inc/qt5/Qt5Widget.hxx
+++ b/vcl/inc/qt5/Qt5Widget.hxx
@@ -45,6 +45,8 @@

    Qt5Frame& m_rFrame;
    bool m_bNonEmptyIMPreeditSeen;
    int m_nDeltaX;
    int m_nDeltaY;

    bool handleKeyEvent(QKeyEvent*, bool);
    void handleMouseButtonEvent(QMouseEvent*, bool);

vcl/qt5/Qt5Widget.cxx

diff --git a/vcl/qt5/Qt5Widget.cxx b/vcl/qt5/Qt5Widget.cxx
index 63eb685..4b378cd 100644
--- a/vcl/qt5/Qt5Widget.cxx
+++ b/vcl/qt5/Qt5Widget.cxx
@@ -179,20 +179,31 @@
    aEvent.mnY = pEvent->pos().y();
    aEvent.mnCode = GetKeyModCode(pEvent->modifiers()) | GetMouseModCode(pEvent->buttons());

    int nDelta = pEvent->angleDelta().x();
    aEvent.mbHorz = true;
    if (!nDelta)
    // mouse wheel ticks are 120, which we map to 3 lines.
    // we have to accumulate for touch scroll to keep track of the absolute delta.

    int nDelta = pEvent->angleDelta().y(), lines;
    aEvent.mbHorz = nDelta == 0;
    if (aEvent.mbHorz)
    {
        nDelta = pEvent->angleDelta().y();
        aEvent.mbHorz = false;
        nDelta = pEvent->angleDelta().x();
        if (!nDelta)
            return;

        m_nDeltaX += nDelta;
        lines = m_nDeltaX / 40;
        m_nDeltaX = m_nDeltaX % 40;
    }
    if (!nDelta)
        return;
    nDelta /= 8;
    else
    {
        m_nDeltaY += nDelta;
        lines = m_nDeltaY / 40;
        m_nDeltaY = m_nDeltaY % 40;
    }

    aEvent.mnDelta = nDelta;
    aEvent.mnNotchDelta = nDelta > 0 ? 1 : -1;
    aEvent.mnScrollLines = 3;
    aEvent.mnNotchDelta = nDelta < 0 ? -1 : 1;
    aEvent.mnScrollLines = std::abs(lines);

    m_rFrame.CallCallback(SalEvent::WheelMouse, &aEvent);
    pEvent->accept();
@@ -479,6 +490,8 @@
    : QWidget(Q_NULLPTR, f)
    , m_rFrame(rFrame)
    , m_bNonEmptyIMPreeditSeen(false)
    , m_nDeltaX(0)
    , m_nDeltaY(0)
{
    create();
    setMouseTracking(true);