Initial commit: monitor-lets-go — automatic monitor layout daemon

2026-06-22 16:22:47 +07:00
commit a4b80616bb
13 changed files with 1708 additions and 0 deletions
@@ -0,0 +1,99 @@
+// Package backend defines the abstraction layer for window-manager-specific
+// monitor management. Each supported compositor (Hyprland, Sway, etc.)
+// implements the Backend interface, encapsulating how monitors are detected,
+// configured, and how hotplug events are received.
+//
+// This is the only WM-dependent code in the project. To add support for a
+// new window manager, implement this interface and register the backend in
+// cmd/monitor-lets-go/main.go.
+package backend
+
+import "context"
+
+// MonitorInfo represents a physical display as reported by the compositor.
+// Fields use JSON tags matching hyprctl -j output; other compositors
+// populate equivalent fields.
+type MonitorInfo struct {
+	Name        string  `json:"name"`
+	Description string  `json:"description"`
+	Make        string  `json:"make"`
+	Model       string  `json:"model"`
+	Serial      string  `json:"serial"`
+	Width       int     `json:"width"`
+	Height      int     `json:"height"`
+	RefreshRate float64 `json:"refreshRate"`
+	X           int     `json:"x"`
+	Y           int     `json:"y"`
+	Scale       float64 `json:"scale"`
+	Enabled     bool    `json:"enabled"`
+}
+
+// MonitorConfig describes the desired state of a single monitor.
+// Used in configuration and passed to ApplyLayout.
+type MonitorConfig struct {
+	Name     string  `yaml:"name"`
+	Enabled  bool    `yaml:"enabled"`
+	Mode     string  `yaml:"mode"`     // "1920x1080@144", "preferred", or empty
+	Position string  `yaml:"position"` // "0x0", "auto", or empty
+	Scale    float64 `yaml:"scale"`    // 1.0, 1.5, etc.
+}
+
+// State represents the current operational mode of the daemon.
+type State int
+
+const (
+	StateUnknown  State = iota
+	StatePortable       // built-in display only
+	StateDocked         // external monitors connected
+)
+
+// String returns a human-readable state name used for config keys and logging.
+func (s State) String() string {
+	switch s {
+	case StatePortable:
+		return "portable"
+	case StateDocked:
+		return "docked"
+	default:
+		return "unknown"
+	}
+}
+
+// EventType identifies the kind of monitor hotplug event.
+type EventType int
+
+const (
+	EventMonitorAdded   EventType = iota
+	EventMonitorRemoved
+)
+
+// Event carries a single monitor hotplug notification from the compositor.
+type Event struct {
+	Type        EventType
+	MonitorName string
+}
+
+// Backend is the abstraction over a window manager's monitor management.
+// Each implementation handles compositor-specific APIs for querying monitors,
+// applying layouts, and subscribing to hotplug events.
+type Backend interface {
+	// Name returns a human-readable backend identifier (e.g. "hyprland").
+	Name() string
+
+	// GetMonitors returns all monitors known to the compositor,
+	// both active and inactive (physically connected but disabled).
+	GetMonitors(ctx context.Context) ([]MonitorInfo, error)
+
+	// ApplyLayout applies a list of monitor configurations atomically.
+	// The backend must ensure no intermediate state where zero monitors
+	// are enabled is ever visible.
+	ApplyLayout(ctx context.Context, monitors []MonitorConfig) error
+
+	// Events returns a channel of hotplug events and a channel of errors.
+	// The caller must read from both channels. When ctx is cancelled,
+	// the backend closes both channels and stops listening.
+	Events(ctx context.Context) (<-chan Event, <-chan error)
+
+	// Close releases any resources held by the backend.
+	Close() error
+}