Refactor and add some documentation (it'll be true soon enough)

internal/config/devices.go

@@ -0,0 +1,118 @@
+package config
+
+import (
+	"fmt"
+	"strings"
+
+	"git.annabunches.net/annabunches/joyful/internal/logger"
+	"github.com/holoplot/go-evdev"
+)
+
+// CreateVirtualDevices will register any configured devices with type = virtual
+// using /dev/uinput, and return a map of those devices.
+//
+// This function assumes you have already called Parse() on the config directory.
+//
+// This function should only be called once, unless you want to create duplicate devices for some reason.
+func (parser *ConfigParser) CreateVirtualDevices() map[string]*evdev.InputDevice {
+	deviceMap := make(map[string]*evdev.InputDevice)
+
+	for _, deviceConfig := range parser.config.Devices {
+		if strings.ToLower(deviceConfig.Type) != DeviceTypeVirtual {
+			continue
+		}
+
+		name := fmt.Sprintf("joyful-%s", deviceConfig.Name)
+		device, err := evdev.CreateDevice(
+			name,
+			// TODO: who knows what these should actually be
+			evdev.InputID{
+				BusType: 0x03,
+				Vendor:  0x4711,
+				Product: 0x0816,
+				Version: 1,
+			},
+			map[evdev.EvType][]evdev.EvCode{
+				evdev.EV_KEY: makeButtons(int(deviceConfig.Buttons)),
+				evdev.EV_ABS: makeAxes(int(deviceConfig.Axes)),
+			},
+		)
+
+		if err != nil {
+			logger.LogIfError(err, "Failed to create virtual device")
+			continue
+		}
+
+		deviceMap[deviceConfig.Name] = device
+		logger.Log(fmt.Sprintf("Created virtual device '%s'", name))
+	}
+
+	return deviceMap
+}
+
+// ConnectPhysicalDevices will create InputDevices corresponding to any registered
+// devices with type = physical. It will also attempt to acquire exclusive access
+// to those devices, to prevent the same inputs from being read on multiple devices.
+//
+// This function assumes you have already called Parse() on the config directory.
+//
+// This function should only be called once.
+func (parser *ConfigParser) ConnectPhysicalDevices() map[string]*evdev.InputDevice {
+	deviceMap := make(map[string]*evdev.InputDevice)
+
+	for _, deviceConfig := range parser.config.Devices {
+		if strings.ToLower(deviceConfig.Type) != DeviceTypePhysical {
+			continue
+		}
+
+		device, err := evdev.OpenByName(deviceConfig.DeviceName)
+		if err != nil {
+			logger.LogError(err, "Failed to open physical device, skipping. Confirm the device name with 'evlist'. Watch out for spaces.")
+			continue
+		}
+
+		// TODO: grab exclusive access to device (add config option)
+
+		logger.Log(fmt.Sprintf("Connected to '%s' as '%s'", deviceConfig.DeviceName, deviceConfig.Name))
+		deviceMap[deviceConfig.Name] = device
+	}
+
+	return deviceMap
+}
+
+func makeButtons(numButtons int) []evdev.EvCode {
+	if numButtons > 56 {
+		numButtons = 56
+		logger.Log("Limiting virtual device buttons to 56")
+	}
+
+	buttons := make([]evdev.EvCode, numButtons)
+
+	startCode := 0x120
+	for i := 0; i < numButtons && i < 16; i++ {
+		buttons[i] = evdev.EvCode(startCode + i)
+	}
+
+	if numButtons > 16 {
+		startCode = 0x2c0
+		for i := 0; i < numButtons-16; i++ {
+			buttons[16+i] = evdev.EvCode(startCode + i)
+		}
+	}
+
+	return buttons
+}
+
+func makeAxes(numAxes int) []evdev.EvCode {
+	if numAxes > 8 {
+		numAxes = 8
+		logger.Log("Limiting virtual device axes to 8")
+	}
+
+	axes := make([]evdev.EvCode, numAxes)
+	for i := 0; i < numAxes; i++ {
+		axes[i] = evdev.EvCode(i)
+	}
+
+	return axes
+}