ui/display/chromeos/x11/native_display_event_dispatcher_x11.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/time/default_tick_clock.h"
   6 #include "ui/display/chromeos/x11/native_display_event_dispatcher_x11.h"
   7 #include "ui/display/chromeos/x11/display_mode_x11.h"
   8 #include "ui/display/chromeos/x11/display_snapshot_x11.h"
   9 #include "ui/events/platform/platform_event_source.h"
  10
  11 #include <X11/extensions/Xrandr.h>
  12
  13 namespace ui {
  14
  15 // static
  16 const int NativeDisplayEventDispatcherX11::kUseCacheAfterStartupMs = 7000;
  17
  18 NativeDisplayEventDispatcherX11::NativeDisplayEventDispatcherX11(
  19     NativeDisplayDelegateX11::HelperDelegate* delegate,
  20     int xrandr_event_base)
  21     : delegate_(delegate),
  22       xrandr_event_base_(xrandr_event_base),
  23       tick_clock_(new base::DefaultTickClock) {
  24   startup_time_ = tick_clock_->NowTicks();
  25 }
  26
  27 NativeDisplayEventDispatcherX11::~NativeDisplayEventDispatcherX11() {}
  28
  29 bool NativeDisplayEventDispatcherX11::CanDispatchEvent(
  30     const PlatformEvent& event) {
  31   return (event->type - xrandr_event_base_ == RRScreenChangeNotify) ||
  32          (event->type - xrandr_event_base_ == RRNotify);
  33 }
  34
  35 uint32_t NativeDisplayEventDispatcherX11::DispatchEvent(
  36     const PlatformEvent& event) {
  37   if (event->type - xrandr_event_base_ == RRScreenChangeNotify) {
  38     VLOG(1) << "Received RRScreenChangeNotify event";
  39     delegate_->UpdateXRandRConfiguration(event);
  40     return ui::POST_DISPATCH_PERFORM_DEFAULT;
  41   }
  42
  43   // Bail out early for everything except RRNotify_OutputChange events
  44   // about an output getting connected or disconnected.
  45   if (event->type - xrandr_event_base_ != RRNotify)
  46     return ui::POST_DISPATCH_PERFORM_DEFAULT;
  47   const XRRNotifyEvent* notify_event = reinterpret_cast<XRRNotifyEvent*>(event);
  48   if (notify_event->subtype != RRNotify_OutputChange)
  49     return ui::POST_DISPATCH_PERFORM_DEFAULT;
  50   const XRROutputChangeNotifyEvent* output_change_event =
  51       reinterpret_cast<XRROutputChangeNotifyEvent*>(event);
  52   const int action = output_change_event->connection;
  53   if (action != RR_Connected && action != RR_Disconnected)
  54     return ui::POST_DISPATCH_PERFORM_DEFAULT;
  55
  56   const bool connected = (action == RR_Connected);
  57   VLOG(1) << "Received RRNotify_OutputChange event:"
  58           << " output=" << output_change_event->output
  59           << " crtc=" << output_change_event->crtc
  60           << " mode=" << output_change_event->mode
  61           << " action=" << (connected ? "connected" : "disconnected");
  62
  63   bool check_cache = (tick_clock_->NowTicks() - startup_time_)
  64                          .InMilliseconds() <= kUseCacheAfterStartupMs;
  65
  66   if (check_cache) {
  67     bool found_changed_output = false;
  68     const std::vector<DisplaySnapshot*>& cached_outputs =
  69         delegate_->GetCachedDisplays();
  70     for (std::vector<DisplaySnapshot*>::const_iterator it =
  71              cached_outputs.begin();
  72          it != cached_outputs.end();
  73          ++it) {
  74       const DisplaySnapshotX11* x11_output =
  75           static_cast<const DisplaySnapshotX11*>(*it);
  76       const DisplayModeX11* x11_mode =
  77           static_cast<const DisplayModeX11*>(x11_output->current_mode());
  78       RRMode mode_id = x11_mode ? x11_mode->mode_id() : None;
  79
  80       // Update if we failed to fetch the external display's ID before.
  81       // Internal display's EDID should always be available.
  82       bool display_id_needs_update =
  83           x11_output->type() != ui::DISPLAY_CONNECTION_TYPE_INTERNAL &&
  84           !x11_output->display_id();
  85
  86       if (x11_output->output() == output_change_event->output) {
  87         if (connected && x11_output->crtc() == output_change_event->crtc &&
  88             mode_id == output_change_event->mode &&
  89             !display_id_needs_update) {
  90           VLOG(1) << "Ignoring event describing already-cached state";
  91           return POST_DISPATCH_PERFORM_DEFAULT;
  92         }
  93         found_changed_output = true;
  94         break;
  95       }
  96     }
  97
  98     if (!connected && !found_changed_output) {
  99       VLOG(1) << "Ignoring event describing already-disconnected output";
 100       return ui::POST_DISPATCH_PERFORM_DEFAULT;
 101     }
 102   }
 103
 104   delegate_->NotifyDisplayObservers();
 105
 106   return ui::POST_DISPATCH_PERFORM_DEFAULT;
 107 }
 108
 109 void NativeDisplayEventDispatcherX11::SetTickClockForTest(
 110     scoped_ptr<base::TickClock> tick_clock) {
 111   tick_clock_ = tick_clock.Pass();
 112   startup_time_ = tick_clock_->NowTicks();
 113 }
 114
 115 }  // namespace ui