Add a factory and defines for native Linux surfaces.

ui/base/linux/touch_event_from_evdev_converter.cc

+// Copyright (c) 2013 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/base/linux/touch_event_from_evdev_converter.h"
+
+#include <cmath>
+
+#include <fcntl.h>
+#include <linux/input.h>
+#include <poll.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/message_loop.h"
+#include "base/message_pump_linux.h"
+#include "ui/base/events/event_constants.h"
+#include "ui/base/events/event.h"
+
+
+namespace {
+
+// Number is determined empirically.
+// TODO(rjkroege): Configure this per device.
+const float kFingerWidth = 25.f;
+
+void DispatchEventHelper(ui::TouchEvent* tev) {
+  base::MessagePumpLinux::Current()->Dispatch(tev);
+}
+
+}  // namespace
+
+namespace ui {
+
+TouchEventFromEvdevConverter::TouchEventFromEvdevConverter(int fd, int id)
+    : pressure_min_(0),
+      pressure_max_(0),
+      x_scale_(1.),
+      y_scale_(1.),
+      current_slot_(0),
+      fd_(fd),
+      id_(id) {
+  Init();
+}
+
+TouchEventFromEvdevConverter::~TouchEventFromEvdevConverter() {
+  if (close(fd_) < 0)
+    DLOG(WARNING) << "failed close on /dev/input/event" << id_;
+}
+
+void TouchEventFromEvdevConverter::Init() {
+  input_absinfo abs = {};
+  if (ioctl(fd_, EVIOCGABS(ABS_MT_SLOT), &abs) != -1) {
+    CHECK_GE(abs.maximum, abs.minimum);
+    CHECK_GE(abs.minimum, 0);
+  } else {
+    DLOG(WARNING) << "failed ioctl EVIOCGABS ABS_MT_SLOT event" << id_;
+  }
+  if (ioctl(fd_, EVIOCGABS(ABS_MT_PRESSURE), &abs) != -1) {
+    pressure_min_ = abs.minimum;
+    pressure_max_ = abs.maximum;
+  } else {
+    DLOG(WARNING) << "failed ioctl EVIOCGABS ABS_MT_PRESSURE event" << id_;
+  }
+  int x_min = 0, x_max = 0;
+  if (ioctl(fd_, EVIOCGABS(ABS_MT_POSITION_X), &abs) != -1) {
+    x_min = abs.minimum;
+    x_max = abs.maximum;
+  } else {
+    LOG(WARNING) << "failed ioctl EVIOCGABS ABS_X event" << id_;
+  }
+  int y_min = 0, y_max = 0;
+  if (ioctl(fd_, EVIOCGABS(ABS_MT_POSITION_Y), &abs) != -1) {
+    y_min = abs.minimum;
+    y_max = abs.maximum;
+  } else {
+    LOG(WARNING) << "failed ioctl EVIOCGABS ABS_Y event" << id_;
+  }
+  const char *display = getenv("ASH_DISPLAY_SPEC");
+  if (x_max && y_max && display) {
+    int screen_width, screen_height;
+    sscanf(display, "%dx%d", &screen_width, &screen_height);
+    x_scale_ = (double)screen_width / (x_max - x_min);
+    y_scale_ = (double)screen_height / (y_max - y_min);
+    LOG(INFO) << "touch input x_scale=" << x_scale_ << " y_scale=" << y_scale_;
+  }
+}
+
+void TouchEventFromEvdevConverter::OnFileCanWriteWithoutBlocking(int /* fd */) {
+  // Read-only file-descriptors.
+  NOTREACHED();
+}
+
+void TouchEventFromEvdevConverter::OnFileCanReadWithoutBlocking(int fd) {
+  input_event inputs[MAX_FINGERS * 6 + 1];
+  ssize_t read_size = read(fd, inputs, sizeof(inputs));
+  if (read_size <= 0)
+    return;
+
+  for (unsigned i = 0; i < read_size / sizeof(*inputs); i++) {
+    const input_event& input = inputs[i];
+    if (input.type == EV_ABS) {
+      switch (input.code) {
+        case ABS_MT_TOUCH_MAJOR:
+          altered_slots_.set(current_slot_);
+          events_[current_slot_].major_ = input.value;
+          break;
+        case ABS_X:
+        case ABS_MT_POSITION_X:
+          altered_slots_.set(current_slot_);
+          events_[current_slot_].x_ = roundf(input.value * x_scale_);
+          break;
+        case ABS_Y:
+        case ABS_MT_POSITION_Y:
+          altered_slots_.set(current_slot_);
+          events_[current_slot_].y_ = roundf(input.value * y_scale_);
+          break;
+        case ABS_MT_TRACKING_ID:
+          altered_slots_.set(current_slot_);
+          if (input.value < 0) {
+            events_[current_slot_].type_ = ET_TOUCH_RELEASED;
+          } else {
+            events_[current_slot_].finger_ = input.value;
+            events_[current_slot_].type_ = ET_TOUCH_PRESSED;
+          }
+          break;
+        case ABS_MT_PRESSURE:
+        case ABS_PRESSURE:
+          altered_slots_.set(current_slot_);
+          events_[current_slot_].pressure_ = input.value - pressure_min_;
+          events_[current_slot_].pressure_ /= pressure_max_ -
+              pressure_min_;
+          break;
+        case ABS_MT_SLOT:
+          current_slot_ = input.value;
+          altered_slots_.set(current_slot_);
+          break;
+       default:
+         NOTREACHED();
+      }
+    } else if (input.type == EV_SYN) {
+      switch (input.code) {
+        case SYN_REPORT:
+          for (int j = 0; j < MAX_FINGERS; j++) {
+            if (altered_slots_[j]) {
+             // TODO(rjkroege): Support elliptical finger regions.
+             TouchEvent* tev = new TouchEvent(events_[j].type_,
+                                              gfx::Point(events_[j].x_,
+                                                         events_[j].y_),
+                                              /* flags */ 0,
+                                              /* touch_id */ j,
+                                              base::TimeDelta::FromMicroseconds(
+                                                  input.time.tv_sec * 1000000 +
+                                                      input.time.tv_usec),
+                                              events_[j].pressure_ *
+                                                  kFingerWidth,
+                                              events_[j].pressure_ *
+                                                  kFingerWidth,
+                                              /* angle */ 0.,
+                                              events_[j].pressure_);
+              events_[j].type_ = ET_TOUCH_MOVED;
+              DispatchEvent(tev);
+            }
+          }
+          altered_slots_.reset();
+          break;
+        case SYN_MT_REPORT:
+        case SYN_CONFIG:
+        case SYN_DROPPED:
+          NOTREACHED() << "Nexus Galaxy doesn't generate SYN_MT events.";
+          break;
+      }
+    } else {
+      NOTREACHED();
+    }
+  }
+}
+
+
+void TouchEventFromEvdevConverter::DispatchEvent(TouchEvent* tev) {
+  base::Callback<void()> event_cb = base::Bind(&DispatchEventHelper,
+                                                    base::Owned(tev));
+  MessageLoop::current()->PostTask(FROM_HERE, event_cb);
+}
+
+}  // namespace ui