Input: Remove device limit for touch input devices

This patch removes the 128 device limit that was imposed on input
devices. Instead of using a fixed size array, a flat_map is used.

The DeviceDataManager also removes entries from the flat_map if a
device has been disconnected.

Test: Manually tested on the faulty device.
Bug: b/137907174
Change-Id: I5e5803aa4fb853bf4129515767c60a2dec81686d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1913717Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Michael Spang <spang@chromium.org>
Commit-Queue: Malay Keshav <malaykeshav@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715624}

ui/events/devices/device_data_manager.cc

@@ -4,12 +4,15 @@
 
 #include "ui/events/devices/device_data_manager.h"
 
+#include <algorithm>
+
 #include "base/at_exit.h"
 #include "base/bind.h"
 #include "base/logging.h"
 #include "ui/display/types/display_constants.h"
 #include "ui/events/devices/input_device_event_observer.h"
 #include "ui/events/devices/touch_device_transform.h"
+#include "ui/events/devices/touchscreen_device.h"
 #include "ui/gfx/geometry/point3_f.h"
 
 // This macro provides the implementation for the observer notification methods.
@@ -79,19 +82,16 @@ void DeviceDataManager::ConfigureTouchDevices(
 }
 
 void DeviceDataManager::ClearTouchDeviceAssociations() {
-  for (size_t i = 0; i < touch_map_.size(); ++i)
-    touch_map_[i] = TouchDeviceTransform();
+  touch_map_.clear();
   for (TouchscreenDevice& touchscreen_device : touchscreen_devices_)
     touchscreen_device.target_display_id = display::kInvalidDisplayId;
 }
 
 void DeviceDataManager::UpdateTouchInfoFromTransform(
     const ui::TouchDeviceTransform& touch_device_transform) {
-  if (!IsTouchDeviceIdValid(touch_device_transform.device_id))
-    return;
+  DCHECK_GE(touch_device_transform.device_id, 0);
 
   touch_map_[touch_device_transform.device_id] = touch_device_transform;
-
   for (TouchscreenDevice& touchscreen_device : touchscreen_devices_) {
     if (touchscreen_device.id == touch_device_transform.device_id) {
       touchscreen_device.target_display_id = touch_device_transform.display_id;
@@ -100,22 +100,41 @@ void DeviceDataManager::UpdateTouchInfoFromTransform(
   }
 }
 
-bool DeviceDataManager::IsTouchDeviceIdValid(int touch_device_id) const {
-  return (touch_device_id > 0 && touch_device_id < kMaxDeviceNum);
+void DeviceDataManager::UpdateTouchMap() {
+  // Remove all entries for devices from the |touch_map_| that are not currently
+  // connected.
+  auto last_iter = std::remove_if(
+      touch_map_.begin(), touch_map_.end(),
+      [this](const std::pair<int, TouchDeviceTransform>& map_entry) {
+        // Check if the given |map_entry| is present in the current list of
+        // connected devices.
+        auto iter = std::find_if(
+            touchscreen_devices_.begin(), touchscreen_devices_.end(),
+            [&map_entry](const TouchscreenDevice& touch_device) {
+              return touch_device.id == map_entry.second.device_id;
+            });
+
+        // Remove the device identified by |map_entry| from |touch_map_| if it
+        // is not present in the list of currently connected devices.
+        return iter != touchscreen_devices_.end();
+      });
+  touch_map_.erase(last_iter, touch_map_.end());
 }
 
 void DeviceDataManager::ApplyTouchRadiusScale(int touch_device_id,
                                               double* radius) {
-  if (IsTouchDeviceIdValid(touch_device_id))
-    *radius = (*radius) * touch_map_[touch_device_id].radius_scale;
+  auto iter = touch_map_.find(touch_device_id);
+  if (iter != touch_map_.end())
+    *radius = (*radius) * iter->second.radius_scale;
 }
 
 void DeviceDataManager::ApplyTouchTransformer(int touch_device_id,
                                               float* x,
                                               float* y) {
-  if (IsTouchDeviceIdValid(touch_device_id)) {
+  auto iter = touch_map_.find(touch_device_id);
+  if (iter != touch_map_.end()) {
     gfx::Point3F point(*x, *y, 0.0);
-    const gfx::Transform& trans = touch_map_[touch_device_id].transform;
+    const gfx::Transform& trans = iter->second.transform;
     trans.TransformPoint(&point);
     *x = point.x();
     *y = point.y();
@@ -150,8 +169,9 @@ bool DeviceDataManager::AreDeviceListsComplete() const {
 
 int64_t DeviceDataManager::GetTargetDisplayForTouchDevice(
     int touch_device_id) const {
-  if (IsTouchDeviceIdValid(touch_device_id))
-    return touch_map_[touch_device_id].display_id;
+  auto iter = touch_map_.find(touch_device_id);
+  if (iter != touch_map_.end())
+    return iter->second.display_id;
   return display::kInvalidDisplayId;
 }
 
@@ -170,6 +190,7 @@ void DeviceDataManager::OnTouchscreenDevicesUpdated(
     touchscreen_device.target_display_id =
         GetTargetDisplayForTouchDevice(touchscreen_device.id);
   }
+  UpdateTouchMap();
   NotifyObserversTouchscreenDeviceConfigurationChanged();
 }
 

ui/events/devices/device_data_manager.h

@@ -11,6 +11,7 @@
 #include <memory>
 #include <vector>
 
+#include "base/containers/flat_map.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "ui/events/devices/device_hotplug_event_observer.h"
@@ -91,7 +92,7 @@ class EVENTS_DEVICES_EXPORT DeviceDataManager
   void ClearTouchDeviceAssociations();
   void UpdateTouchInfoFromTransform(
       const ui::TouchDeviceTransform& touch_device_transform);
-  bool IsTouchDeviceIdValid(int touch_device_id) const;
+  void UpdateTouchMap();
 
   void NotifyObserversTouchscreenDeviceConfigurationChanged();
   void NotifyObserversKeyboardDeviceConfigurationChanged();
@@ -117,10 +118,8 @@ class EVENTS_DEVICES_EXPORT DeviceDataManager
   // Set to true when ConfigureTouchDevices() is called.
   bool are_touchscreen_target_displays_valid_ = false;
 
-  // Contains touchscreen device info for each device mapped by device ID. Will
-  // have default values if the device with corresponding ID isn't a touchscreen
-  // or doesn't exist.
-  std::array<TouchDeviceTransform, kMaxDeviceNum> touch_map_;
+  // Contains touchscreen device info for each device mapped by device ID.
+  base::flat_map<int, TouchDeviceTransform> touch_map_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceDataManager);
 };