Implemented smooth scrolling using xinput2 in X11.

ui/events/devices/x11/device_data_manager_x11.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/events/devices/x11/device_data_manager_x11.h"
 
 #include <X11/extensions/XInput.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/Xlib.h>
 
@@ skipping 197 matching lines @@
   return true;
 }
 
 bool DeviceDataManagerX11::IsXInput2Available() const {
   return xi_opcode_ != -1;
 }
 
 void DeviceDataManagerX11::UpdateDeviceList(Display* display) {
   cmt_devices_.reset();
   touchpads_.reset();
+  scrollclass_devices_.reset();
   master_pointers_.clear();
   for (int i = 0; i < kMaxDeviceNum; ++i) {
     valuator_count_[i] = 0;
     valuator_lookup_[i].clear();
     data_type_lookup_[i].clear();
     valuator_min_[i].clear();
     valuator_max_[i].clear();
+    scroll_data_[i].horizontal.number = -1;
+    scroll_data_[i].vertical.number = -1;
     for (int j = 0; j < kMaxSlotNum; j++)
       last_seen_valuator_[i][j].clear();
   }
 
   // Find all the touchpad devices.
   const XDeviceList& dev_list =
       ui::DeviceListCacheX11::GetInstance()->GetXDeviceList(display);
   Atom xi_touchpad = XInternAtom(display, XI_TOUCHPAD, false);
   for (int i = 0; i < dev_list.count; ++i)
     if (dev_list[i].type == xi_touchpad)
@@ skipping 35 matching lines @@
       continue;
 
     valuator_lookup_[deviceid].resize(DT_LAST_ENTRY, -1);
     data_type_lookup_[deviceid].resize(
         valuator_count_[deviceid], DT_LAST_ENTRY);
     valuator_min_[deviceid].resize(DT_LAST_ENTRY, 0);
     valuator_max_[deviceid].resize(DT_LAST_ENTRY, 0);
     for (int j = 0; j < kMaxSlotNum; j++)
       last_seen_valuator_[deviceid][j].resize(DT_LAST_ENTRY, 0);
     for (int j = 0; j < info.num_classes; ++j) {
-      if (info.classes[j]->type != XIValuatorClass)
-        continue;
-
-      XIValuatorClassInfo* v =
-          reinterpret_cast<XIValuatorClassInfo*>(info.classes[j]);
-      for (int data_type = 0; data_type < DT_LAST_ENTRY; ++data_type) {
-        if (v->label == atoms[data_type]) {
-          valuator_lookup_[deviceid][data_type] = v->number;
-          data_type_lookup_[deviceid][v->number] = data_type;
-          valuator_min_[deviceid][data_type] = v->min;
-          valuator_max_[deviceid][data_type] = v->max;
-          if (IsCMTDataType(data_type))
-            possible_cmt = true;
-          break;
-        }
+      if (info.classes[j]->type == XIValuatorClass) {
+        if (UpdateValuatorClassDevice(
+                reinterpret_cast<XIValuatorClassInfo*>(info.classes[j]), atoms,
+                deviceid))
+          possible_cmt = true;
+      } else if (info.classes[j]->type == XIScrollClass) {
+        UpdateScrollClassDevice(
+            reinterpret_cast<XIScrollClassInfo*>(info.classes[j]), deviceid);
       }
     }
 
     if (possible_cmt && !not_cmt)
       cmt_devices_[deviceid] = true;
   }
 }
 
+bool DeviceDataManagerX11::UpdateValuatorClassDevice(
+    XIValuatorClassInfo* valuator_class_info,
+    Atom* atoms,
+    int deviceid) {
+  DCHECK(deviceid >= 0 && deviceid < kMaxDeviceNum);
+  for (int data_type = 0; data_type < DT_LAST_ENTRY; ++data_type) {
+    if (valuator_class_info->label == atoms[data_type]) {
+      valuator_lookup_[deviceid][data_type] = valuator_class_info->number;
+      data_type_lookup_[deviceid][valuator_class_info->number] = data_type;
+      valuator_min_[deviceid][data_type] = valuator_class_info->min;
+      valuator_max_[deviceid][data_type] = valuator_class_info->max;
+      if (IsCMTDataType(data_type))
+        return true;
+    }
+  }
+  return false;
+}
+
+void DeviceDataManagerX11::UpdateScrollClassDevice(
+    XIScrollClassInfo* scroll_class_info,
+    int deviceid) {
+  DCHECK(deviceid >= 0 && deviceid < kMaxDeviceNum);
+  ScrollInfo& info = scroll_data_[deviceid];
+  switch (scroll_class_info->scroll_type) {
+    case XIScrollTypeVertical:
+      info.vertical.number = scroll_class_info->number;
+      info.vertical.increment = scroll_class_info->increment;
+      info.vertical.position = 0;
+      info.vertical.seen = false;
+      break;
+    case XIScrollTypeHorizontal:
+      info.horizontal.number = scroll_class_info->number;
+      info.horizontal.increment = scroll_class_info->increment;
+      info.horizontal.position = 0;
+      info.horizontal.seen = false;
+      break;
+  }
+  scrollclass_devices_[deviceid] = true;
+}
+
 bool DeviceDataManagerX11::GetSlotNumber(const XIDeviceEvent* xiev, int* slot) {
   ui::TouchFactory* factory = ui::TouchFactory::GetInstance();
   if (!factory->IsMultiTouchDevice(xiev->sourceid)) {
     *slot = 0;
     return true;
   }
   return factory->QuerySlotForTrackingID(xiev->detail, slot);
 }
 
 void DeviceDataManagerX11::GetEventRawData(const XEvent& xev, EventData* data) {
@@ skipping 102 matching lines @@
     return false;
 
   XIDeviceEvent* xievent =
       static_cast<XIDeviceEvent*>(native_event->xcookie.data);
   CHECK(xievent->sourceid >= 0);
   if (xievent->sourceid >= kMaxDeviceNum)
     return false;
   return cmt_devices_[xievent->sourceid];
 }
 
+int DeviceDataManagerX11::GetScrollClassEventDetail(
+    const base::NativeEvent& native_event) const {
+  if (native_event->type != GenericEvent)
+    return SCROLL_TYPE_NO_SCROLL;
+
+  XIDeviceEvent* xievent =
+      static_cast<XIDeviceEvent*>(native_event->xcookie.data);
+  if (xievent->sourceid >= kMaxDeviceNum)
+    return SCROLL_TYPE_NO_SCROLL;
+  if (!scrollclass_devices_[xievent->sourceid])
+    return SCROLL_TYPE_NO_SCROLL;
+  int horizontal_id = scroll_data_[xievent->sourceid].horizontal.number;
+  int vertical_id = scroll_data_[xievent->sourceid].vertical.number;
+  return (XIMaskIsSet(xievent->valuators.mask, horizontal_id)
+              ? SCROLL_TYPE_HORIZONTAL
+              : 0) |
+         (XIMaskIsSet(xievent->valuators.mask, vertical_id)
+              ? SCROLL_TYPE_VERTICAL
+              : 0);
+}
+
+int DeviceDataManagerX11::GetScrollClassDeviceDetail(
+    const base::NativeEvent& native_event) const {
+  XEvent& xev = *native_event;
+  if (xev.type != GenericEvent)
+    return SCROLL_TYPE_NO_SCROLL;
+
+  XIDeviceEvent* xiev = static_cast<XIDeviceEvent*>(xev.xcookie.data);
+  if (xiev->sourceid >= kMaxDeviceNum || xiev->deviceid >= kMaxDeviceNum)
+    return SCROLL_TYPE_NO_SCROLL;
+  const int sourceid = xiev->sourceid;
+  ScrollInfo device_data = scroll_data_[sourceid];
+  return (device_data.vertical.number >= 0 ? SCROLL_TYPE_VERTICAL : 0) |
+         (device_data.horizontal.number >= 0 ? SCROLL_TYPE_HORIZONTAL : 0);
+}
+
 bool DeviceDataManagerX11::IsCMTGestureEvent(
     const base::NativeEvent& native_event) const {
   return (IsScrollEvent(native_event) ||
           IsFlingEvent(native_event) ||
           IsCMTMetricsEvent(native_event));
 }
 
 bool DeviceDataManagerX11::HasEventData(
     const XIDeviceEvent* xiev, const DataType type) const {
   CHECK(xiev->sourceid >= 0);
@@ skipping 72 matching lines @@
   if (data.find(DT_CMT_SCROLL_Y) != data.end())
     *y_offset = data[DT_CMT_SCROLL_Y];
   if (data.find(DT_CMT_ORDINAL_X) != data.end())
     *x_offset_ordinal = data[DT_CMT_ORDINAL_X];
   if (data.find(DT_CMT_ORDINAL_Y) != data.end())
     *y_offset_ordinal = data[DT_CMT_ORDINAL_Y];
   if (data.find(DT_CMT_FINGER_COUNT) != data.end())
     *finger_count = static_cast<int>(data[DT_CMT_FINGER_COUNT]);
 }
 
+void DeviceDataManagerX11::GetScrollClassOffsets(
+    const base::NativeEvent& native_event,
+    double* x_offset,
+    double* y_offset) {
+  XEvent& xev = *native_event;
+  if (xev.type != GenericEvent)
+    return;
+
+  *x_offset = 0;
+  *y_offset = 0;
+
+  XIDeviceEvent* xiev = static_cast<XIDeviceEvent*>(xev.xcookie.data);
+  if (xiev->sourceid >= kMaxDeviceNum || xiev->deviceid >= kMaxDeviceNum)
+    return;
+  const int sourceid = xiev->sourceid;
+  double* valuators = xiev->valuators.values;
+
+  ScrollInfo& info = scroll_data_[sourceid];
+
+  const int horizontal_number = info.horizontal.number;
+  const int vertical_number = info.vertical.number;
+
+  for (int i = 0; i <= valuator_count_[sourceid]; ++i) {
+    if (!XIMaskIsSet(xiev->valuators.mask, i))
+      continue;
+    if (i == horizontal_number) {
+      double value = *valuators;
+      double delta = 0;
+
+      if (info.horizontal.seen)
+        delta = info.horizontal.position - value;
+
+      info.horizontal.seen = true;
+      info.horizontal.position = value;
+      *x_offset = delta;
+      NormalizeScrollData(sourceid, true, x_offset);
+    } else if (i == vertical_number) {
+      double value = *valuators;
+      double delta = 0;
+      if (info.vertical.seen)
+        delta = info.vertical.position - value;

[bokan, 2015/12/01 18:29:27]

I still see scroll jumping when I have a mouse plugged in, repro:

1. Scroll down with the touchpad
2. Scroll down with the mouse wheel
3. Scroll down with the touchpad again

It seems like the position value gets clobbered by the mousewheel here so the
delta computed on the first touchpad scroll in #3 is bogus. Should mouse wheels
be handled in here? Otherwise you'll need to find a way to clear the |seen| bit
when we change devices.

+
+      info.vertical.seen = true;
+      info.vertical.position = value;
+      *y_offset = delta;
+      NormalizeScrollData(sourceid, false, y_offset);
+    }
+    valuators++;
+  }
+}
+
+void DeviceDataManagerX11::InvalidateScrollClasses() {
+  for (int i = 0; i < kMaxDeviceNum; i++) {
+    scroll_data_[i].horizontal.seen = false;
+    scroll_data_[i].vertical.seen = false;
+  }
+}
+
 void DeviceDataManagerX11::GetFlingData(
     const base::NativeEvent& native_event,
     float* vx,
     float* vy,
     float* vx_ordinal,
     float* vy_ordinal,
     bool* is_cancel) {
   *vx = 0;
   *vy = 0;
   *vx_ordinal = 0;
@@ skipping 73 matching lines @@
   double max_value;
   double min_value;
   if (GetDataRange(deviceid, type, &min_value, &max_value)) {
     *value = (*value - min_value) / (max_value - min_value);
     DCHECK(*value >= 0.0 && *value <= 1.0);
     return true;
   }
   return false;
 }
 
+bool DeviceDataManagerX11::NormalizeScrollData(unsigned int deviceid,
+                                               bool horizontal,
+                                               double* value) {
+  if (deviceid >= static_cast<unsigned int>(kMaxDeviceNum))
+    return false;
+  if (horizontal && scroll_data_[deviceid].horizontal.number < 0)
+    return false;
+  if (!horizontal && scroll_data_[deviceid].vertical.number < 0)
+    return false;
+  double increment = horizontal ? scroll_data_[deviceid].horizontal.increment
+                                : scroll_data_[deviceid].vertical.increment;
+
+  *value /= increment;
+  return true;
+}
+
 bool DeviceDataManagerX11::GetDataRange(int deviceid,
                                         const DataType type,
                                         double* min,
                                         double* max) {
   CHECK(deviceid >= 0);
   if (deviceid >= kMaxDeviceNum)
     return false;
   if (valuator_lookup_[deviceid][type] >= 0) {
     *min = valuator_min_[deviceid][type];
     *max = valuator_max_[deviceid][type];
@@ skipping 164 matching lines @@
     } else {
       keyboards.erase(it);
       ++blocked_iter;
     }
   }
   // Notify base class of updated list.
   DeviceDataManager::OnKeyboardDevicesUpdated(keyboards);
 }
 
 }  // namespace ui