GCPadEmu: only connected if default device connected

This lets Dolphin know if a configured GameCube Controller should actually
be treated as connected or not.

Talked to @JMC47 a bit about this last night. My use-case is that all of
my controllers are the same hardware (Xbox One controllers) so share the
same configuration (modulo device number). Treating them all as always
connected isn't a problem for most games, but in some (Smash Bros.) it
forces me to go find a keyboard/mouse and unconfigure any controllers
that I don't actually have connected. Hotplugging devices (works on macOS,
at least) + this patch remove my need to ever touch the Controller Config
dialog while in a game.

This patch makes the following changes:

- A new `BooleanSetting` in `GCPadEmu` called "Always Connected", which
  defaults to false.
- `ControllerEmu` tracks whether the default device is connected on every
  call to `UpdateReferences()`.
- `GCPadEmu.GetStatus()` now sets err bit to `PAD_ERR_NO_CONTROLLER` if
  the default device isn't connected.
- `SIDevice_GCController` handles `PAD_ERR_NO_CONTROLLER` by imitating the
  behaviour of `SIDevice_Null` (as far as I can tell, this is the only use
  of the error bit from `GCPadStatus`).

I wanted to add an OSD message akin to the ones when Wiimotes get
connected/disconnected, but I haven't yet found where to put the logic.

1 files changed, 7 insertions, 0 deletions

diff --git a/Source/Core/InputCommon/ControllerEmu/ControllerEmu.cpp b/Source/Core/InputCommon/ControllerEmu/ControllerEmu.cpp
index cf70fa8468..98b9e5828b 100644
--- a/Source/Core/InputCommon/ControllerEmu/ControllerEmu.cpp
+++ b/Source/Core/InputCommon/ControllerEmu/ControllerEmu.cpp
@@ -34,6 +34,8 @@ std::unique_lock<std::recursive_mutex> EmulatedController::GetStateLock()
 void EmulatedController::UpdateReferences(const ControllerInterface& devi)
 {
   const auto lock = GetStateLock();
+  m_default_device_is_connected = devi.HasConnectedDevice(m_default_device);
+
   for (auto& ctrlGroup : groups)
   {
     for (auto& control : ctrlGroup->controls)
@@ -48,6 +50,11 @@ void EmulatedController::UpdateReferences(const ControllerInterface& devi)
   }
 }
 
+bool EmulatedController::IsDefaultDeviceConnected() const
+{
+  return m_default_device_is_connected;
+}
+
 const ciface::Core::DeviceQualifier& EmulatedController::GetDefaultDevice() const
 {
   return m_default_device;