Add support for Joystick hats.

internal/mappingrules/interfaces.go

@@ -22,9 +22,6 @@ type RuleTarget interface {
 	// (e.g., inverting the value if Inverted == true)
 	NormalizeValue(int32) int32
 
-	// MatchEvent returns true if the provided device and input event are a match for this rule target
-	ValidateEvent(*evdev.InputDevice, *evdev.InputEvent) bool
-
 	// CreateEvent creates an event that can be emitted on a virtual device.
 	// For RuleTargetModeSelect, this method modifies the active mode and returns nil.
 	//
@@ -35,6 +32,7 @@ type RuleTarget interface {
 	// for most implementations.
 	CreateEvent(int32, *string) *evdev.InputEvent
 
+	// MatchEvent returns true if the provided device and input event are a match for this rule target
 	MatchEvent(device Device, event *evdev.InputEvent) bool
 }
 

internal/mappingrules/mapping_rule_hat.go

@@ -0,0 +1,45 @@
+package mappingrules
+
+import (
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"github.com/holoplot/go-evdev"
+)
+
+// A Simple Mapping Rule can map a button to a button or an axis to an axis.
+type MappingRuleHat struct {
+	MappingRuleBase
+	Input  *RuleTargetHat
+	Output *RuleTargetHat
+}
+
+func NewMappingRuleHat(ruleConfig configparser.RuleConfigHat,
+	pDevs map[string]Device,
+	vDevs map[string]Device,
+	base MappingRuleBase) (*MappingRuleHat, error) {
+
+	input, err := NewRuleTargetHatFromConfig(ruleConfig.Input, pDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	output, err := NewRuleTargetHatFromConfig(ruleConfig.Output, vDevs)
+	if err != nil {
+		return nil, err
+	}
+
+	return &MappingRuleHat{
+		MappingRuleBase: base,
+		Input:           input,
+		Output:          output,
+	}, nil
+}
+
+func (rule *MappingRuleHat) MatchEvent(device Device, event *evdev.InputEvent, mode *string) (*evdev.InputDevice, *evdev.InputEvent) {
+	if !rule.MappingRuleBase.modeCheck(mode) ||
+		!rule.Input.MatchEvent(device, event) {
+		return nil, nil
+	}
+
+	// The cast here is safe because the interface is only ever different for unit tests
+	return rule.Output.Device.(*evdev.InputDevice), rule.Output.CreateEvent(rule.Input.NormalizeValue(event.Value), mode)
+}

internal/mappingrules/rule_target_hat.go

@@ -0,0 +1,53 @@
+package mappingrules
+
+import (
+	"fmt"
+
+	"git.annabunches.net/annabunches/joyful/internal/configparser"
+	"git.annabunches.net/annabunches/joyful/internal/eventcodes"
+	"github.com/holoplot/go-evdev"
+)
+
+type RuleTargetHat struct {
+	Device   Device
+	Hat      evdev.EvCode
+	Inverted bool
+}
+
+func NewRuleTargetHatFromConfig(config configparser.RuleTargetConfigHat, devs map[string]Device) (*RuleTargetHat, error) {
+	dev, ok := devs[config.Device]
+	if !ok {
+		return nil, fmt.Errorf("device '%s' not found", config.Device)
+	}
+
+	code, err := eventcodes.ParseCode(config.Hat, eventcodes.CodePrefixAxis)
+	if err != nil {
+		return nil, err
+	}
+
+	return &RuleTargetHat{
+		Device:   dev,
+		Hat:      code,
+		Inverted: config.Inverted,
+	}, nil
+}
+
+func (target *RuleTargetHat) NormalizeValue(value int32) int32 {
+	if !target.Inverted {
+		return value
+	}
+
+	return value * -1
+}
+
+func (target *RuleTargetHat) CreateEvent(value int32, _ *string) *evdev.InputEvent {
+	return &evdev.InputEvent{
+		Type:  evdev.EV_ABS,
+		Code:  target.Hat,
+		Value: value,
+	}
+}
+
+func (target *RuleTargetHat) MatchEvent(device Device, event *evdev.InputEvent) bool {
+	return device == target.Device && event.Code == target.Hat
+}