This patch implements Chromium's Aura gesture recognizer in terms of utouch-grail and utouch-frame …

ui/aura/gestures/gesture_recognizer_grail.cc

+// Copyright (c) 2012 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/aura/gestures/gesture_recognizer_grail.h"
+
+#include <utouch/grail.h>
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/singleton.h"
+#include "base/time.h"
+#include "ui/aura/event.h"
+#include "ui/aura/window.h"
+#include "ui/base/events.h"
+#include "ui/base/touch/touch_factory.h"
+#include "ui/base/x/x11_util.h"
+
+namespace {
+
+static const base::TimeDelta kLongPressTimeThreshold

[sadrul, 2012/04/03 19:52:01]

Should you just use values from GestureConfiguration instead?

+= base::TimeDelta::FromMilliseconds(3000);
+
+static const base::TimeDelta kDoubleTapTimeout
+= base::TimeDelta::FromMilliseconds(300);
+
+bool GetDeviceAndWindowFromEvent(
+    const UFEvent event,
+    UFDevice* device,
+    UFWindowId* window_id) {
+
+  UFFrame frame;
+  UFStatus status = frame_event_get_property(event, UFEventPropertyFrame,
+                                             &frame);
+  if (status != UFStatusSuccess) {
+    LOG(ERROR) << "failed to get frame from event\n";
+    return false;
+  }
+
+  *device = frame_frame_get_device(frame);
+  *window_id = frame_frame_get_window_id(frame);
+
+  char * deviceName;
+  if (UFStatusSuccess ==
+      frame_device_get_property(*device, UFDevicePropertyName, &deviceName))
+    DLOG(INFO) << "Considering device: " << deviceName;
+  else
+    DLOG(INFO) << "Problem reading out device name.";
+
+  return true;
+}
+
+// Subscribes to the grail instance (handle)
+// for two-finger taps, drags and pinches. Please

[sadrul, 2012/04/03 19:52:01]

Does this mean there will be no single-finger gestures (e.g. tap, scroll)?

+// note that subscribing to the grail instance is non-blocking.
+// Returns an int with boolean semantics to indicate success or failure.
+int SubscribeForGestures(
+    UGHandle handle,
+    UFDevice device,
+    ::Window window,
+    UGSubscription subscription) {
+  char * deviceName = NULL;
+  if (UFStatusSuccess ==
+      frame_device_get_property(device, UFDevicePropertyName, &deviceName))
+    DLOG(INFO) << "Subscribing to device: " << deviceName;
+
+  UGStatus status;
+
+  int touches_start = 2;
+  int touches_max = 2;
+  int touches_min = 2;
+  int atomic = 1;
+
+  UFWindowId window_id = frame_x11_create_window_id(window);
+  const UGGestureTypeMask mask =
+      UGGestureTypeDrag |
+      UGGestureTypePinch |
+      UGGestureTypeTap;
+  status = grail_subscription_new(&subscription);
+  if (status != UGStatusSuccess) {
+    LOG(ERROR) << "Failed to create subscription";
+    return 0;
+  }
+
+  status = grail_subscription_set_property(subscription,
+                                           UGSubscriptionPropertyDevice,
+                                           &device);
+  if (status != UGStatusSuccess) {
+    LOG(ERROR) << "Failed to set subscription device";
+    return 0;
+  }
+
+  status = grail_subscription_set_property(subscription,
+                                           UGSubscriptionPropertyWindow,
+                                           &window_id);
+  if (status != UGStatusSuccess) {
+    LOG(ERROR) << "Failed to set subscription window";
+    return 0;
+  }
+
+  status = grail_subscription_set_property(subscription,
+                                           UGSubscriptionPropertyAtomicGestures,
+                                           &atomic);
+  if (status != UGStatusSuccess) {
+    LOG(ERROR) << "Failed to set atomic gestures subscription property.";
+    return 0;
+  }
+
+  status = grail_subscription_set_property(subscription,
+                                           UGSubscriptionPropertyTouchesStart,
+                                           &touches_start);
+  if (status != UGStatusSuccess) {
+    LOG(ERROR) << "Failed to set subscription start touches.";
+    return 0;
+  }
+
+  status = grail_subscription_set_property(subscription,
+                                           UGSubscriptionPropertyTouchesMaximum,
+                                           &touches_max);
+  if (status != UGStatusSuccess) {
+    LOG(ERROR) << "Failed to set subscription start touches.";
+    return 0;
+  }
+
+  status = grail_subscription_set_property(subscription,
+                                           UGSubscriptionPropertyTouchesMinimum,
+                                           &touches_min);
+  if (status != UGStatusSuccess) {
+    LOG(ERROR) << "Failed to set subscription min touches.";
+    return 0;
+  }
+
+  status = grail_subscription_set_property(subscription,
+                                           UGSubscriptionPropertyMask,
+                                           &mask);
+  if (status != UGStatusSuccess) {
+    LOG(ERROR) << "Failed to set subscription mask";
+    return 0;
+  }
+
+  status = grail_subscription_activate(handle, subscription);
+  if (status != UGStatusSuccess) {
+    LOG(ERROR) << "Failed to activate subscription\n";
+    return 0;
+  }
+
+  DLOG(INFO) << "Successfully configured and activated grail subscription";
+
+  return 1;
+}
+
+}  // namespace
+
+namespace aura {
+
+// Implements a singleton for a raw grail instance and
+// makes sure that RAII.
+class GrailHolder {
+ public:
+  // Returns the singleton instance
+  static GrailHolder* GetInstance() {
+    return Singleton<GrailHolder>::get();
+  }
+
+  // Returns the handle managed by the instance
+  UGHandle handle() const {
+    return utouch_grail_handle_;
+  }
+
+ private:
+  friend struct DefaultSingletonTraits<GrailHolder>;
+
+  GrailHolder()
+      : utouch_grail_handle_(NULL) {
+    if (UGStatusSuccess != grail_new(
+            ui::TouchFactory::GetInstance()->handle(),
+            &utouch_grail_handle_)) {
+      LOG(ERROR) << "Problem initializing grail api.";
+    } else {
+      fd_set set;
+      FD_ZERO(&set);
+      int fd = grail_get_fd(utouch_grail_handle_);
+      FD_SET(fd, &set);
+    }
+  }
+
+  ~GrailHolder() {
+    if (utouch_grail_handle_ != NULL)
+      grail_delete_v3(utouch_grail_handle_);
+  }
+
+  UGHandle utouch_grail_handle_;
+
+  DISALLOW_COPY_AND_ASSIGN(GrailHolder);
+};
+
+struct GestureRecognizerGrail::Private {
+  typedef std::map<UFDevice, UGSubscription> SubscriptionMap;
+
+  explicit Private(RootWindow* window)
+      : flags_(0),
+        window_(window) {
+  }
+
+  ~Private() {
+    SubscriptionMap::iterator it;
+    for (it = subscriptions_.begin();
+         it != subscriptions_.end();
+         ++it) {
+      grail_subscription_delete(it->second);
+    }
+  }
+
+  void UpdateFrameInstance(XEvent* xEvent) {
+    if (xEvent != NULL) {
+      if (UFStatusSuccess !=
+          frame_x11_process_event(
+              ui::TouchFactory::GetInstance()->handle(),
+              &xEvent->xcookie)) {
+        LOG(ERROR) << "Failed to inject X event";
+      }
+    } else {
+      LOG(ERROR) << "Failed to extract native event";
+    }
+  }
+
+  void ProcessFrameEvents() {
+    UFEvent ufEvent;
+    while (frame_get_event(
+               ui::TouchFactory::GetInstance()->handle(),
+               &ufEvent) ==
+           UFStatusSuccess) {
+      grail_process_frame_event(
+          GrailHolder::GetInstance()->handle(),
+          ufEvent);
+
+      switch (frame_event_get_type(ufEvent)) {
+        case UFEventTypeDeviceAdded: {
+          UFDevice device = NULL;
+          UFStatus status =  frame_event_get_property(ufEvent,
+                                                      UFEventPropertyDevice,
+                                                      &device);
+
+          if (status != UFStatusSuccess)
+            LOG(ERROR) << "Failed to get device from event.";
+          else
+            SubscribeForGestures(
+                GrailHolder::GetInstance()->handle(),
+                device,
+                ui::TouchFactory::GetInstance()->native_root_window_aura(),

[sadrul, 2012/04/03 19:52:01]

This should use window_->native_window() or something of the sort.

+                subscriptions_[device]);
+
+          break;
+        }
+
+        case UFEventTypeDeviceRemoved: {
+          UFDevice device = NULL;
+          UFStatus status = frame_event_get_property(ufEvent,
+                                                     UFEventPropertyDevice,
+                                                     &device);
+
+          if (status != UFStatusSuccess) {
+            LOG(ERROR) << "Failed to get device from event.";
+          } else {
+            Private::SubscriptionMap::iterator it =
+                subscriptions_.find(device);
+            if (it != subscriptions_.end()) {
+              grail_subscription_delete(it->second);
+              subscriptions_.erase(it);
+            }
+          }
+          break;
+        }
+        default:
+          break;
+      }
+
+      frame_event_unref(ufEvent);
+    }
+  }
+
+  void ProcessSlice(
+      UGSlice slice,
+      uint64_t time,
+      const TouchEvent& event,
+      GestureRecognizer::Gestures * result) {
+    DCHECK(result != NULL);
+
+    const UGGestureTypeMask recognized = grail_slice_get_recognized(slice);
+
+    if (recognized & UGGestureTypePinch) {
+      linked_ptr<GestureEvent> lp(ProcessPinch(slice, event));
+      if (lp.get() != NULL)
+        result->push_back(lp);
+    }
+
+    if (recognized & UGGestureTypeDrag) {
+      linked_ptr<GestureEvent> lp(ProcessDrag(slice, event));
+      if (lp.get() != NULL)
+        result->push_back(lp);
+    }
+
+    if (recognized & UGGestureTypeTap) {
+      linked_ptr<GestureEvent> lp(ProcessTap(slice, event));
+      if (lp.get() != NULL)
+        result->push_back(lp);
+    }
+  }
+
+  linked_ptr<GestureEvent> ProcessDrag(UGSlice slice,

[rjkroege, 2012/04/02 17:05:15]

why not use a scoped_ptr?

+                                       const TouchEvent& touch_event) {
+    ui::EventType event_type = ui::ET_UNKNOWN;
+
+    switch (grail_slice_get_state(slice)) {

[rjkroege, 2012/04/02 17:05:15]

This code would have to be updated as we re-structure some of the gesture
protocol.

+      case UGGestureStateBegin:
+        event_type = ui::ET_GESTURE_SCROLL_BEGIN;
+        break;
+      case UGGestureStateUpdate:
+        event_type = ui::ET_GESTURE_SCROLL_UPDATE;
+        break;
+      case UGGestureStateEnd:
+        event_type = ui::ET_GESTURE_SCROLL_END;
+        break;
+    }
+
+    const UGTransform *transform =
+        grail_slice_get_transform(slice);
+
+    GestureEvent::Properties props;
+    props.delta_x = -(*transform)[0][2];
+    props.delta_y = -(*transform)[1][2];
+
+    GestureEvent * result = new GestureEvent(event_type,
+                                             touch_event.x(),
+                                             touch_event.y(),
+                                             touch_event.flags(),
+                                             base::Time::Now(),
+                                             props);
+    return linked_ptr<GestureEvent>(result);
+  }
+
+  linked_ptr<GestureEvent> ProcessPinch(UGSlice slice,
+                                        const TouchEvent & touch_event) {
+    ui::EventType event_type = ui::ET_UNKNOWN;
+    switch (grail_slice_get_state(slice)) {
+      case UGGestureStateBegin:
+        event_type = ui::ET_GESTURE_PINCH_BEGIN;
+        break;
+      case UGGestureStateUpdate:
+        event_type = ui::ET_GESTURE_PINCH_UPDATE;
+        break;
+      case UGGestureStateEnd:
+        event_type = ui::ET_GESTURE_PINCH_END;
+        break;
+    }
+
+    const UGTransform *transform =
+        grail_slice_get_cumulative_transform(slice);
+
+    GestureEvent::Properties props;
+    props.delta_x = (*transform)[0][0];
+    props.delta_y = (*transform)[1][1];
+    props.scale_x = (*transform)[0][0];
+    props.scale_y = (*transform)[1][1];
+
+    GestureEvent * result = new GestureEvent(event_type,
+                                             touch_event.x(),
+                                             touch_event.y(),
+                                             touch_event.flags(),
+                                             base::Time::Now(),
+                                             props);
+
+    return linked_ptr<GestureEvent>(result);
+  }
+
+  linked_ptr<GestureEvent> ProcessTap(UGSlice slice,
+                                      const TouchEvent & touch_event) {
+    ui::EventType event_type = ui::ET_UNKNOWN;
+    switch (grail_slice_get_state(slice)) {
+      case UGGestureStateBegin:
+        gesture_tap_start_ = base::Time::Now();
+        return linked_ptr<GestureEvent>(NULL);
+        break;
+      case UGGestureStateUpdate:
+        return linked_ptr<GestureEvent>(NULL);
+        break;
+      case UGGestureStateEnd: {
+        base::Time now = base::Time::Now();
+        base::TimeDelta dlp = now - gesture_tap_start_;
+        base::TimeDelta ddt = now - last_gesture_tap_completed_;
+        if (dlp >= kLongPressTimeThreshold) {
+          event_type = ui::ET_GESTURE_LONG_PRESS;
+        } else if (ddt < kDoubleTapTimeout) {
+          event_type = ui::ET_GESTURE_DOUBLE_TAP;
+        } else {
+          event_type = ui::ET_GESTURE_TAP;
+          last_gesture_tap_completed_ = now;
+        }
+        gesture_tap_start_ = base::Time::Now();
+        break;
+      }
+    }
+
+    return linked_ptr<GestureEvent>(new GestureEvent(
+        event_type,
+        touch_event.x(),
+        touch_event.y(),
+        touch_event.flags(),
+        base::Time::Now(),
+        GestureEvent::Properties()));
+  }
+
+  int flags_;
+  RootWindow* window_;
+
+  base::Time last_gesture_tap_completed_;
+  base::Time gesture_tap_start_;
+
+  SubscriptionMap subscriptions_;
+};
+
+
+////////////////////////////////////////////////////////////////////////////////
+// GestureRecognizerGrail Public:
+
+GestureRecognizerGrail::GestureRecognizerGrail(RootWindow* window)
+    : d_(new Private(window)) {
+}
+
+GestureRecognizer::Gestures*
+GestureRecognizerGrail::ProcessTouchEventForGesture(
+    const TouchEvent& event,
+    ui::TouchStatus status) {
+
+  d_->UpdateFrameInstance(
+      static_cast<XEvent*>(event.native_event()));
+
+  d_->ProcessFrameEvents();
+
+  Gestures * result = new Gestures();
+
+  UGEvent ugEvent;
+  while (grail_get_event(GrailHolder::GetInstance()->handle(), &ugEvent) ==
+         UGStatusSuccess) {
+    switch (grail_event_get_type(ugEvent)) {
+      case UGEventTypeSlice: {
+        UGSlice slice;
+        UGStatus status;
+        status = grail_event_get_property(ugEvent,
+                                          UGEventPropertySlice, &slice);
+        if (status != UGStatusSuccess) {
+          break;
+        }
+
+        d_->ProcessSlice(slice,
+                         grail_event_get_time(ugEvent),
+                         event,
+                         result);
+        break;
+      }
+      default:
+        break;
+    }
+
+    grail_event_unref(ugEvent);
+  }
+
+  return result;
+}
+
+void GestureRecognizerGrail::QueueTouchEventForGesture(
+    Window* /*window*/,
+    const TouchEvent& /*event*/) {
+}
+
+GestureRecognizer::Gestures* GestureRecognizerGrail::AdvanceTouchQueue(
+    Window* /*window*/,
+    bool /*processed*/) {
+  return NULL;
+}
+
+void GestureRecognizerGrail::FlushTouchQueue(Window* /*window*/) {
+}
+
+// GestureRecognizer, static
+GestureRecognizer* GestureRecognizer::Create(RootWindow* window) {
+  return new GestureRecognizerGrail(window);
+}
+
+}  // namespace aura
+