ControllerInterface: Make the ID assigning code common

This makes the device ID assigning code common to all backends, by
moving it to AddDevice() instead of copy-pasting or replicating
the logic in the backends.

Also, to prepare for hotplugging, instead of relying on a name usage
count, the new ID assigning system always starts from ID 0 and tries
to assign the first ID that is not used.

1 files changed, 14 insertions, 0 deletions

diff --git a/Source/Core/InputCommon/ControllerInterface/ControllerInterface.cpp b/Source/Core/InputCommon/ControllerInterface/ControllerInterface.cpp
index cbf2c4dfbb..700d390b92 100644
--- a/Source/Core/InputCommon/ControllerInterface/ControllerInterface.cpp
+++ b/Source/Core/InputCommon/ControllerInterface/ControllerInterface.cpp
@@ -143,6 +143,20 @@ void ControllerInterface::Shutdown()
 void ControllerInterface::AddDevice(std::shared_ptr<ciface::Core::Device> device)
 {
   std::lock_guard<std::mutex> lk(m_devices_mutex);
+  // Try to find an ID for this device
+  int id = 0;
+  while (true)
+  {
+    const auto it = std::find_if(m_devices.begin(), m_devices.end(), [&device, &id](const auto& d) {
+      return d->GetSource() == device->GetSource() && d->GetName() == device->GetName() &&
+             d->GetId() == id;
+    });
+    if (it == m_devices.end())  // no device with the same name with this ID, so we can use it
+      break;
+    else
+      id++;
+  }
+  device->SetId(id);
   m_devices.emplace_back(std::move(device));
 }