tdf#122459 Qt5 IM underline pre-edit

This simply always underlines the pre-edit text, so it'S easier to
see what text block is currently IM edited.

Change-Id: I45145e4faa872c44eb6583ac6f335dd40fe3e53e
Reviewed-on: https://gerrit.libreoffice.org/65856
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>
(cherry picked from commit f2ee532640fa200ada55ac51fbe47bad260aec7e)
Reviewed-on: https://gerrit.libreoffice.org/65858
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>
diff --git a/vcl/qt5/Qt5Widget.cxx b/vcl/qt5/Qt5Widget.cxx
index 462f196..4eaac16 100644
--- a/vcl/qt5/Qt5Widget.cxx
+++ b/vcl/qt5/Qt5Widget.cxx
@@ -41,6 +41,7 @@

#include <cairo.h>
#include <headless/svpgdi.hxx>
#include <vcl/commandevent.hxx>

void Qt5Widget::paintEvent(QPaintEvent* pEvent)
{
@@ -449,6 +450,10 @@
    {
        aInputEvent.maText = toOUString(pEvent->preeditString());
        aInputEvent.mnCursorPos = 0;
        sal_Int32 nLength = aInputEvent.maText.getLength();
        std::vector<ExtTextInputAttr> aTextAttrs(nLength, ExtTextInputAttr::Underline);
        if (nLength)
            aInputEvent.mpTextAttr = &aTextAttrs[0];
        m_pFrame->CallCallback(SalEvent::ExtTextInput, &aInputEvent);
        pEvent->accept();
    }