events: Introduce PlatformEventDispatcher and PlatformEventSource.

ui/events/platform/x11/x11_event_source.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/platform/x11/x11_event_source.h"
+
+#include <glib.h>
+#include <X11/extensions/XInput2.h>
+#include <X11/X.h>
+#include <X11/Xlib.h>
+#include <X11/XKBlib.h>
+
+#include "base/logging.h"
+#include "base/message_loop/message_loop.h"
+#include "ui/events/platform/platform_event_dispatcher.h"
+
+namespace ui {
+
+namespace {
+
+struct GLibX11Source : public GSource {
+  // Note: The GLibX11Source is created and destroyed by GLib. So its
+  // constructor/destructor may or may not get called.
+  XDisplay* display;
+  GPollFD* poll_fd;
+};
+
+gboolean XSourcePrepare(GSource* source, gint* timeout_ms) {
+  GLibX11Source* gxsource = static_cast<GLibX11Source*>(source);
+  if (XPending(gxsource->display))
+    *timeout_ms = 0;
+  else
+    *timeout_ms = -1;
+  return FALSE;
+}
+
+gboolean XSourceCheck(GSource* source) {
+  GLibX11Source* gxsource = static_cast<GLibX11Source*>(source);
+  return XPending(gxsource->display);
+}
+
+gboolean XSourceDispatch(GSource* source,
+                         GSourceFunc unused_func,
+                         gpointer data) {
+  X11EventSource* x11_source = static_cast<X11EventSource*>(data);
+  x11_source->DispatchXEvents();
+  return TRUE;
+}
+
+GSourceFuncs XSourceFuncs = {
+  XSourcePrepare,
+  XSourceCheck,
+  XSourceDispatch,
+  NULL
+};
+
+int g_xinput_opcode = -1;
+
+bool InitializeXInput2(XDisplay* display) {
+  if (!display)
+    return false;
+
+  int event, err;
+
+  int xiopcode;
+  if (!XQueryExtension(display, "XInputExtension", &xiopcode, &event, &err)) {
+    DVLOG(1) << "X Input extension not available.";
+    return false;
+  }
+  g_xinput_opcode = xiopcode;
+
+#if defined(USE_XI2_MT)
+  // USE_XI2_MT also defines the required XI2 minor minimum version.
+  int major = 2, minor = USE_XI2_MT;
+#else
+  int major = 2, minor = 0;
+#endif
+  if (XIQueryVersion(display, &major, &minor) == BadRequest) {
+    DVLOG(1) << "XInput2 not supported in the server.";
+    return false;
+  }
+#if defined(USE_XI2_MT)
+  if (major < 2 || (major == 2 && minor < USE_XI2_MT)) {
+    DVLOG(1) << "XI version on server is " << major << "." << minor << ". "
+            << "But 2." << USE_XI2_MT << " is required.";
+    return false;
+  }
+#endif
+
+  return true;
+}
+
+bool InitializeXkb(XDisplay* display) {
+  if (!display)
+    return false;
+
+  int opcode, event, error;
+  int major = XkbMajorVersion;
+  int minor = XkbMinorVersion;
+  if (!XkbQueryExtension(display, &opcode, &event, &error, &major, &minor)) {
+    DVLOG(1) << "Xkb extension not available.";
+    return false;
+  }
+
+  // Ask the server not to send KeyRelease event when the user holds down a key.
+  // crbug.com/138092
+  Bool supported_return;
+  if (!XkbSetDetectableAutoRepeat(display, True, &supported_return)) {
+    DVLOG(1) << "XKB not supported in the server.";
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace
+
+X11EventSource::X11EventSource(XDisplay* display)
+    : display_(display),
+      x_source_(NULL) {
+  CHECK(display_);
+  InitializeXInput2(display_);
+  InitializeXkb(display_);
+
+  InitXSource();
+}
+
+X11EventSource::~X11EventSource() {
+  g_source_destroy(x_source_);
+  g_source_unref(x_source_);
+}
+
+// static
+X11EventSource* X11EventSource::GetInstance() {
+  return static_cast<X11EventSource*>(PlatformEventSource::GetInstance());
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// X11EventSource, public
+
+void X11EventSource::DispatchXEvents() {
+  DCHECK(display_);
+  // Handle all pending events.
+  // It may be useful to eventually align this event dispatch with vsync, but
+  // not yet.
+  while (XPending(display_)) {
+    XEvent xevent;
+    XNextEvent(display_, &xevent);
+    uint32_t action = DispatchEvent(&xevent);
+    if (action & POST_DISPATCH_QUIT_LOOP)
+      break;
+  }
+}
+
+void X11EventSource::BlockUntilWindowMapped(XID window) {
+  XEvent event;
+  do {
+    // Block until there's a message of |event_mask| type on |w|. Then remove
+    // it from the queue and stuff it in |event|.
+    XWindowEvent(display_, window, StructureNotifyMask, &event);
+    DispatchEvent(&event);
+  } while (event.type != MapNotify);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// X11EventSource, private
+
+void X11EventSource::InitXSource() {
+  CHECK(!x_source_);
+  CHECK(display_) << "Unable to get connection to X server";
+
+  x_poll_.reset(new GPollFD());
+  x_poll_->fd = ConnectionNumber(display_);
+  x_poll_->events = G_IO_IN;
+  x_poll_->revents = 0;
+
+  GLibX11Source* glib_x_source = static_cast<GLibX11Source*>
+      (g_source_new(&XSourceFuncs, sizeof(GLibX11Source)));
+  glib_x_source->display = display_;
+  glib_x_source->poll_fd = x_poll_.get();
+
+  x_source_ = glib_x_source;
+  g_source_add_poll(x_source_, x_poll_.get());
+  g_source_set_can_recurse(x_source_, TRUE);
+  g_source_set_callback(x_source_, NULL, this, NULL);
+  g_source_attach(x_source_, g_main_context_default());
+}
+
+uint32_t X11EventSource::DispatchEvent(XEvent* xevent) {
+  bool have_cookie = false;
+  if (xevent->type == GenericEvent &&
+      XGetEventData(xevent->xgeneric.display, &xevent->xcookie)) {
+    have_cookie = true;
+  }
+  int action = PlatformEventSource::DispatchEvent(xevent);
+  if (have_cookie)
+    XFreeEventData(xevent->xgeneric.display, &xevent->xcookie);
+  return action;
+}
+
+}  // namespace ui