Associate internal touchscreen to internal display

Currently we associate touchscreen to display based on matching
resolution. But there could be cases the internal touchscreen
reports a resolution that does not match any display resolution,
or the internal display and external display have the same resolution
so we don't know which display to match the touchscreen to.

This patch adds a logic that if we have internal touchscreen and
internal display, we should match them first regardless of the
resolution.

We already have the information about which display is internal display.
For deciding internal touchscreen, we query X to get the touchscreen's
/dev/input/eventX  node, and call a script is_touchscreen_internal
(which checks if the device is a I2C device) to decide whether the
touchscreen is internal or not.

BUG=chrome-os-partner:29398
TEST=touch position is correctly mapped on Blaze in extending mode, with
     external monitor having 1920x1280 resolution.

Review URL: https://codereview.chromium.org/394063004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283641 0039d316-1c4b-4281-b951-d872f2087c98

ui/display/chromeos/touchscreen_delegate_impl.cc

@@ -23,7 +23,38 @@ void TouchscreenDelegateImpl::AssociateTouchscreens(
     std::vector<DisplayConfigurator::DisplayState>* displays) {
   std::set<int> no_match_touchscreen;
   std::vector<TouchscreenDevice> devices = touch_device_manager_->GetDevices();
+
+  int internal_touchscreen = -1;
+  for (size_t i = 0; i < devices.size(); ++i) {
+    if (devices[i].is_internal) {
+      internal_touchscreen = i;
+      break;
+    }
+  }
+
+  DisplayConfigurator::DisplayState* internal_state = NULL;
+  for (size_t i = 0; i < displays->size(); ++i) {
+    DisplayConfigurator::DisplayState* state = &(*displays)[i];
+    if (state->display->type() == DISPLAY_CONNECTION_TYPE_INTERNAL &&
+        state->display->native_mode() &&
+        state->touch_device_id == 0) {
+      internal_state = state;
+      break;
+    }
+  }
+
+  if (internal_state && internal_touchscreen >= 0) {
+    internal_state->touch_device_id = devices[internal_touchscreen].id;
+    VLOG(2) << "Found internal touchscreen for internal display "
+            << internal_state->display->display_id() << " touch_device_id "
+            << internal_state->touch_device_id << " size "
+            << devices[internal_touchscreen].size.ToString();
+  }
+
   for (size_t i = 0; i < devices.size(); ++i) {
+    if (internal_state &&
+        internal_state->touch_device_id == devices[i].id)
+      continue;
     bool found_mapping = false;
     for (size_t j = 0; j < displays->size(); ++j) {
       DisplayConfigurator::DisplayState* state = &(*displays)[j];

ui/display/chromeos/touchscreen_delegate_impl_unittest.cc

@@ -48,8 +48,9 @@ class TouchscreenDelegateImplTest : public testing::Test {
     delegate_.reset(new TouchscreenDelegateImpl(
         scoped_ptr<TouchscreenDeviceManager>(device_manager_)));
 
-    // Internal display. Must not be matched to a touch screen unless the size
-    // matches.
+    // Internal display will always match to internal touchscreen. If internal
+    // touchscreen can't be detected, it is then associated to a touch screen
+    // with matching size.
     TestDisplaySnapshot* snapshot = new TestDisplaySnapshot();
     DisplayMode* mode = new DisplayMode(gfx::Size(1920, 1080), false, 60.0);
     snapshot->set_type(DISPLAY_CONNECTION_TYPE_INTERNAL);
@@ -110,8 +111,8 @@ TEST_F(TouchscreenDelegateImplTest, NoTouchscreens) {
 }
 
 TEST_F(TouchscreenDelegateImplTest, OneToOneMapping) {
-  device_manager_->AddDevice(TouchscreenDevice(1, gfx::Size(800, 600)));
-  device_manager_->AddDevice(TouchscreenDevice(2, gfx::Size(1024, 768)));
+  device_manager_->AddDevice(TouchscreenDevice(1, gfx::Size(800, 600), false));
+  device_manager_->AddDevice(TouchscreenDevice(2, gfx::Size(1024, 768), false));
 
   std::vector<DisplayConfigurator::DisplayState> display_states =
       GetDisplayStates();
@@ -124,7 +125,7 @@ TEST_F(TouchscreenDelegateImplTest, OneToOneMapping) {
 }
 
 TEST_F(TouchscreenDelegateImplTest, MapToCorrectDisplaySize) {
-  device_manager_->AddDevice(TouchscreenDevice(2, gfx::Size(1024, 768)));
+  device_manager_->AddDevice(TouchscreenDevice(2, gfx::Size(1024, 768), false));
 
   std::vector<DisplayConfigurator::DisplayState> display_states =
       GetDisplayStates();
@@ -137,8 +138,8 @@ TEST_F(TouchscreenDelegateImplTest, MapToCorrectDisplaySize) {
 }
 
 TEST_F(TouchscreenDelegateImplTest, MapWhenSizeDiffersByOne) {
-  device_manager_->AddDevice(TouchscreenDevice(1, gfx::Size(801, 600)));
-  device_manager_->AddDevice(TouchscreenDevice(2, gfx::Size(1023, 768)));
+  device_manager_->AddDevice(TouchscreenDevice(1, gfx::Size(801, 600), false));
+  device_manager_->AddDevice(TouchscreenDevice(2, gfx::Size(1023, 768), false));
 
   std::vector<DisplayConfigurator::DisplayState> display_states =
       GetDisplayStates();
@@ -151,8 +152,8 @@ TEST_F(TouchscreenDelegateImplTest, MapWhenSizeDiffersByOne) {
 }
 
 TEST_F(TouchscreenDelegateImplTest, MapWhenSizesDoNotMatch) {
-  device_manager_->AddDevice(TouchscreenDevice(1, gfx::Size(1022, 768)));
-  device_manager_->AddDevice(TouchscreenDevice(2, gfx::Size(802, 600)));
+  device_manager_->AddDevice(TouchscreenDevice(1, gfx::Size(1022, 768), false));
+  device_manager_->AddDevice(TouchscreenDevice(2, gfx::Size(802, 600), false));
 
   std::vector<DisplayConfigurator::DisplayState> display_states =
       GetDisplayStates();
@@ -164,4 +165,20 @@ TEST_F(TouchscreenDelegateImplTest, MapWhenSizesDoNotMatch) {
   EXPECT_EQ(2, display_states[3].touch_device_id);
 }
 
+TEST_F(TouchscreenDelegateImplTest, MapInternalTouchscreen) {
+  device_manager_->AddDevice(
+      TouchscreenDevice(1, gfx::Size(1920, 1080), false));
+  device_manager_->AddDevice(TouchscreenDevice(2, gfx::Size(9999, 888), true));
+
+  std::vector<DisplayConfigurator::DisplayState> display_states =
+      GetDisplayStates();
+  delegate_->AssociateTouchscreens(&display_states);
+
+  // Internal touchscreen is always mapped to internal display.
+  EXPECT_EQ(2, display_states[0].touch_device_id);
+  EXPECT_EQ(1, display_states[1].touch_device_id);
+  EXPECT_EQ(TouchscreenDevice::kInvalidId, display_states[2].touch_device_id);
+  EXPECT_EQ(TouchscreenDevice::kInvalidId, display_states[3].touch_device_id);
+}
+
 }  // namespace ui

ui/display/chromeos/x11/touchscreen_device_manager_x11.cc

@@ -9,9 +9,88 @@
 
 #include <cmath>
 #include <set>
-
+#include <string>
+#include <vector>
+
+#include "base/command_line.h"
+#include "base/files/file_enumerator.h"
+#include "base/logging.h"
+#include "base/process/launch.h"
+#include "base/strings/string_util.h"
+#include "base/sys_info.h"
 #include "ui/gfx/x/x11_types.h"
 
+namespace {
+
+// We consider the touchscreen to be internal if it is an I2c device.
+// With the device id, we can query X to get the device's dev input
+// node eventXXX. Then we search all the dev input nodes registered
+// by I2C devices to see if we can find eventXXX.
+bool IsTouchscreenInternal(XDisplay* dpy, int device_id) {
+  using base::FileEnumerator;
+  using base::FilePath;
+
+  if (!base::SysInfo::IsRunningOnChromeOS())
+    return false;
+
+  // Input device has a property "Device Node" pointing to its dev input node,
+  // e.g.   Device Node (250): "/dev/input/event8"
+  Atom device_node = XInternAtom(dpy, "Device Node", False);
+  if (device_node == None)
+    return false;
+
+  Atom actual_type;
+  int actual_format;
+  unsigned long nitems, bytes_after;
+  unsigned char* data;
+  XDevice* dev = XOpenDevice(dpy, device_id);
+  if (!dev)
+    return false;
+
+  if (XGetDeviceProperty(dpy, dev, device_node, 0, 1000, False,
+                         AnyPropertyType, &actual_type, &actual_format,
+                         &nitems, &bytes_after, &data) != Success) {
+    XCloseDevice(dpy, dev);
+    return false;
+  }
+  base::FilePath dev_node_path(reinterpret_cast<char*>(data));
+  XFree(data);
+  XCloseDevice(dpy, dev);
+
+  std::string event_node = dev_node_path.BaseName().value();
+  if (event_node.empty() ||
+      !StartsWithASCII(event_node, "event", false)) {
+    return false;
+  }
+
+  // Extract id "XXX" from "eventXXX"
+  std::string event_node_id = event_node.substr(5);
+
+  // I2C input device registers its dev input node at
+  // /sys/bus/i2c/devices/*/input/inputXXX/eventXXX
+  FileEnumerator i2c_enum(FilePath(FILE_PATH_LITERAL("/sys/bus/i2c/devices/")),
+                          false,
+                          base::FileEnumerator::DIRECTORIES);
+  for (FilePath i2c_name = i2c_enum.Next();
+       !i2c_name.empty();
+       i2c_name = i2c_enum.Next()) {
+    FileEnumerator input_enum(i2c_name.Append(FILE_PATH_LITERAL("input")),
+                              false,
+                              base::FileEnumerator::DIRECTORIES,
+                              FILE_PATH_LITERAL("input*"));
+    for (base::FilePath input = input_enum.Next();
+         !input.empty();
+         input = input_enum.Next()) {
+      if (input.BaseName().value().substr(5) == event_node_id)
+        return true;
+    }
+  }
+
+  return false;
+}
+
+}  // namespace
+
 namespace ui {
 
 TouchscreenDeviceManagerX11::TouchscreenDeviceManagerX11()
@@ -70,8 +149,10 @@ std::vector<TouchscreenDevice> TouchscreenDeviceManagerX11::GetDevices() {
     // Touchscreens should have absolute X and Y axes, and be direct touch
     // devices.
     if (width > 0.0 && height > 0.0 && is_direct_touch) {
+      bool is_internal = IsTouchscreenInternal(display_, info[i].deviceid);
       devices.push_back(TouchscreenDevice(info[i].deviceid,
-                                          gfx::Size(width, height)));
+                                          gfx::Size(width, height),
+                                          is_internal));
     }
   }
 

ui/display/types/chromeos/touchscreen_device.cc

@@ -9,8 +9,11 @@ namespace ui {
 // static
 const int TouchscreenDevice::kInvalidId = 0;
 
-TouchscreenDevice::TouchscreenDevice(int id, const gfx::Size& size)
+TouchscreenDevice::TouchscreenDevice(int id,
+                                     const gfx::Size& size,
+                                     bool is_internal)
     : id(id),
-      size(size) {}
+      size(size),
+      is_internal(is_internal) {}
 
 }  // namespace ui

ui/display/types/chromeos/touchscreen_device.h

@@ -14,13 +14,16 @@ namespace ui {
 struct DISPLAY_TYPES_EXPORT TouchscreenDevice {
   static const int kInvalidId;
 
-  TouchscreenDevice(int id, const gfx::Size& size);
+  TouchscreenDevice(int id, const gfx::Size& size, bool is_internal);
 
   // ID of the touch screen. This ID must uniquely identify the touch screen.
   int id;
 
   // Size of the touch screen area.
   gfx::Size size;
+
+  // True if this is an internal touchscreen.
+  bool is_internal;
 };
 
 }  // namespace ui