From 53d1e26ff553b9eda5041929101c0ed054fc775b Mon Sep 17 00:00:00 2001
From: Allan Sandfeld Jensen <allan.jensen@qt.io>
Date: Fri, 14 Feb 2020 11:36:32 +0100
Subject: [PATCH] High resolution wheel-event support from libinput

Is necessary because the support was added using a new event
and a new getter.

[ChangeLog][QtGui][libinput] Can now use the hires scrolling API
from libinput 1.19, adding this feature to QPAs using libinput directly

Task-number: QTBUG-96227
Change-Id: Ie30281de2f6391389e9e6049bc4117d3a8f63ad1
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
---
 src/gui/configure.cmake                       | 22 +++++++++++++++++++
 .../input/libinput/qlibinputhandler.cpp       |  4 ++++
 .../input/libinput/qlibinputpointer.cpp       | 16 ++++++++++++--
 3 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/src/gui/configure.cmake b/src/gui/configure.cmake
index ea6752806e..a7fb77d48a 100644
--- a/src/gui/configure.cmake
+++ b/src/gui/configure.cmake
@@ -512,6 +512,23 @@ xcb_xkb_get_kbd_by_name_replies_key_names_value_list_sizeof(nullptr, 0, 0, 0, 0,
 }
 ")
 
+# libinput_hires_wheel_support
+qt_config_compile_test(libinput_hires_wheel_support
+    LABEL "libinput hires wheel support"
+    LIBRARIES
+        Libinput::Libinput
+    CODE
+"#include <libinput.h>
+int main(void)
+{
+    /* BEGIN TEST: */
+libinput_event_type type = LIBINPUT_EVENT_POINTER_SCROLL_WHEEL;
+libinput_event_pointer_get_scroll_value_v120(nullptr, LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL);
+    /* END TEST: */
+    return 0;
+}
+")
+
 # special case begin
 # directwrite (assumes DirectWrite2)
 qt_config_compile_test(directwrite
@@ -678,6 +695,10 @@ qt_feature("libinput-axis-api" PRIVATE
     LABEL "axis API in libinput"
     CONDITION QT_FEATURE_libinput AND ON
 )
+qt_feature("libinput-hires-wheel-support" PRIVATE
+    LABEL "HiRes wheel support in libinput"
+    CONDITION QT_FEATURE_libinput AND TEST_libinput_hires_wheel_support
+)
 qt_feature("lgmon"
     LABEL "lgmon"
     CONDITION libs.lgmon OR FIXME
@@ -1223,6 +1244,7 @@ qt_configure_end_summary_section() # end of "Qt Gui" section
 qt_configure_add_summary_section(NAME "Features used by QPA backends")
 qt_configure_add_summary_entry(ARGS "evdev")
 qt_configure_add_summary_entry(ARGS "libinput")
+qt_configure_add_summary_entry(ARGS "libinput_hires_wheel_support")
 qt_configure_add_summary_entry(ARGS "integrityhid")
 qt_configure_add_summary_entry(ARGS "mtdev")
 qt_configure_add_summary_entry(ARGS "tslib")
diff --git a/src/platformsupport/input/libinput/qlibinputhandler.cpp b/src/platformsupport/input/libinput/qlibinputhandler.cpp
index 95dfb46d16..bd7827feb8 100644
--- a/src/platformsupport/input/libinput/qlibinputhandler.cpp
+++ b/src/platformsupport/input/libinput/qlibinputhandler.cpp
@@ -208,7 +208,11 @@ void QLibInputHandler::processEvent(libinput_event *ev)
     case LIBINPUT_EVENT_POINTER_MOTION_ABSOLUTE:
         m_pointer->processAbsMotion(libinput_event_get_pointer_event(ev));
         break;
+#if QT_CONFIG(libinput_hires_wheel_support)
+    case LIBINPUT_EVENT_POINTER_SCROLL_WHEEL:
+#else
     case LIBINPUT_EVENT_POINTER_AXIS:
+#endif
         m_pointer->processAxis(libinput_event_get_pointer_event(ev));
         break;
     case LIBINPUT_EVENT_KEYBOARD_KEY:
diff --git a/src/platformsupport/input/libinput/qlibinputpointer.cpp b/src/platformsupport/input/libinput/qlibinputpointer.cpp
index db9e81b5df..bf26075f7c 100644
--- a/src/platformsupport/input/libinput/qlibinputpointer.cpp
+++ b/src/platformsupport/input/libinput/qlibinputpointer.cpp
@@ -133,16 +133,28 @@ void QLibInputPointer::processAxis(libinput_event_pointer *e)
         angleDelta.setX(qRound(value));
 #else
     if (libinput_event_pointer_has_axis(e, LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL)) {
+#if QT_CONFIG(libinput_hires_wheel_support)
+        value = libinput_event_pointer_get_scroll_value_v120(e, LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL);
+#else
         value = libinput_event_pointer_get_axis_value(e, LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL);
+#endif
         angleDelta.setY(qRound(value));
     }
     if (libinput_event_pointer_has_axis(e, LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL)) {
+#if QT_CONFIG(libinput_hires_wheel_support)
+        value = libinput_event_pointer_get_scroll_value_v120(e, LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL);
+#else
         value = libinput_event_pointer_get_axis_value(e, LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL);
+#endif
         angleDelta.setX(qRound(value));
     }
 #endif
-    const int factor = 8;
-    angleDelta *= -factor;
+#if QT_CONFIG(libinput_hires_wheel_support)
+    const int factor = -1;
+#else
+    const int factor = -8;
+#endif
+    angleDelta *= factor;
     Qt::KeyboardModifiers mods = QGuiApplicationPrivate::inputDeviceManager()->keyboardModifiers();
     QWindowSystemInterface::handleWheelEvent(nullptr, m_pos, m_pos, QPoint(), angleDelta, mods);
 }