feat(tui): support horizontal flips (screen mirror) for rotations (#77)

## What does this PR do?

Adds `L` keybind to flip the screen on top of rotations.
[Source](https://wiki.hypr.land/Configuring/Monitors/?utm_source=chatgpt.com#rotating):
```
0 -> normal (no transforms)
1 -> 90 degrees
2 -> 180 degrees
3 -> 270 degrees
4 -> flipped
5 -> flipped + 90 degrees
6 -> flipped + 180 degrees
7 -> flipped + 270 degrees
```

## Why is this change important?

Some users might need to flip their screens when using projectors etc.

## How to test this PR locally?

`make pre-push`

## Related issues

Closes #72

Author: fiffeek

Makefile

@@ -258,6 +258,8 @@ record/preview/daemon: build/docs
 
 demo: record/preview
 
+record/all: demo record/previews record/preview/daemon
+
 record/previews: build/docs
 	$(MAKE) record/preview RECORD_TARGET=views
 	$(MAKE) record/preview RECORD_TARGET=monitor_view

docs/docs/quickstart/tui.md

@@ -106,6 +106,7 @@ Once you select a monitor with `Enter`, it enters **EDITING** mode. In this mode
 | Key | Action |
 |-----|--------|
 | `r` | Rotate the monitor by 90 degrees (cycles through 0 → 90 → 180 → 270 → 0) |
+| `L` | Flip (mirror) monitor horizontally |
 
 :::note
 Cannot rotate disabled monitors

internal/hypr/types.go

@@ -80,6 +80,9 @@ func (m *MonitorSpec) Validate() error {
 	if m.SdrSaturation == 0.0 {
 		m.SdrSaturation = 1.0
 	}
+	if m.Transform < 0 || m.Transform > 7 {
+		return fmt.Errorf(".transform is invalid for monitor id %d: %d < 0 || %d > 7", m.ID, m.Transform, m.Transform)
+	}
 
 	return nil
 }

internal/tui/main_test.go

@@ -1,13 +1,16 @@
-package tui
+package tui_test
 
 import (
+	"flag"
 	"os"
 	"testing"
 
 	"github.com/charmbracelet/lipgloss"
 	"github.com/muesli/termenv"
 )
 
+var regenerate = flag.Bool("regenerate", false, "regenerate fixtures instead of comparing")
+
 func TestMain(m *testing.M) {
 	lipgloss.SetColorProfile(termenv.Ascii)
 	os.Exit(m.Run())

internal/tui/messages.go

@@ -116,6 +116,7 @@ const (
 	OperationNameAdjustSdrSaturation
 	OperationNameHydrate
 	OperationNameReloadHyprDestination
+	OperationNameFlipMonitor
 )
 
 type OperationStatus struct {
@@ -171,6 +172,8 @@ func (o OperationStatus) String() string {
 		operationName = "Render Hypr Config"
 	case OperationNameReloadHyprDestination:
 		operationName = "Reload Hypr Destination"
+	case OperationNameFlipMonitor:
+		operationName = "Flip Monitor"
 	default:
 		operationName = "Operation"
 	}
@@ -202,6 +205,7 @@ func OperationStatusCmd(name OperationName, err error) tea.Cmd {
 		OperationNameMatchingProfile,
 		OperationNameHydrate,
 		OperationNameReloadHyprDestination,
+		OperationNameFlipMonitor,
 	}
 	showSuccessToUser := slices.Contains(criticalOperations, name)
 	return func() tea.Msg {
@@ -260,6 +264,10 @@ type ToggleMonitorCommand struct {
 	MonitorID int
 }
 
+type FlipMonitorCommand struct {
+	MonitorID int
+}
+
 type ChangeColorPresetCommand struct {
 	Preset ColorPreset
 }
@@ -501,6 +509,14 @@ func previewScaleMonitorCmd(monitorID int, scale float64) tea.Cmd {
 	}
 }
 
+func flipMonitorCmd(monitor *MonitorSpec) tea.Cmd {
+	return func() tea.Msg {
+		return FlipMonitorCommand{
+			MonitorID: *monitor.ID,
+		}
+	}
+}
+
 func toggleMonitorCmd(monitor *MonitorSpec) tea.Cmd {
 	return func() tea.Msg {
 		return ToggleMonitorCommand{

internal/tui/monitor_editor.go

@@ -137,6 +137,21 @@ func (e *MonitorEditorStore) RotateMonitor(monitorID int) tea.Cmd {
 	return OperationStatusCmd(OperationNameRotate, nil)
 }
 
+func (e *MonitorEditorStore) FlipMonitor(monitorID int) tea.Cmd {
+	monitor, _, err := e.FindByID(monitorID)
+	if err != nil {
+		return OperationStatusCmd(OperationNameFlipMonitor, err)
+	}
+
+	if monitor.Disabled {
+		return OperationStatusCmd(OperationNameFlipMonitor, ErrMonitorDisabled)
+	}
+
+	monitor.ToggleFlip()
+
+	return OperationStatusCmd(OperationNameFlipMonitor, nil)
+}
+
 func (e *MonitorEditorStore) ToggleVRR(monitorID int) tea.Cmd {
 	monitor, _, err := e.FindByID(monitorID)
 	if err != nil {

internal/tui/monitor_list.go

@@ -105,7 +105,7 @@ func (m MonitorItem) DescriptionLines() []string {
 		m.monitor.ModePretty(),
 		m.monitor.ScalePretty(),
 		m.monitor.VRRPretty(),
-		m.monitor.RotationPretty(),
+		m.monitor.RotationPretty(true),
 		m.monitor.PositionPretty(),
 		m.monitor.MirrorPretty(),
 	}
@@ -125,6 +125,7 @@ type MonitorListKeyMap struct {
 	rotate        key.Binding
 	scale         key.Binding
 	color         key.Binding
+	flip          key.Binding
 	changeMode    key.Binding
 	vrr           key.Binding
 	toggle        key.Binding
@@ -169,6 +170,10 @@ func NewMonitorListKeyMap() *MonitorListKeyMap {
 			key.WithKeys("C"),
 			key.WithHelp("C", "color"),
 		),
+		flip: key.NewBinding(
+			key.WithKeys("L"),
+			key.WithHelp("L", "flip"),
+		),
 	}
 }
 
@@ -183,6 +188,7 @@ func (m MonitorListKeyMap) ShortHelp(state AppState) []key.Binding {
 			m.toggle,
 			m.mirror,
 			m.color,
+			m.flip,
 		}
 	}
 	return []key.Binding{
@@ -292,6 +298,12 @@ func (d MonitorDelegate) Update(msg tea.Msg, m *list.Model) tea.Cmd {
 				return nil
 			}
 			cmds = append(cmds, toggleMonitorCmd(item.monitor))
+		case key.Matches(msg, d.keymap.flip):
+			logrus.Debugf("List called with flip")
+			if !item.Editing() {
+				return nil
+			}
+			cmds = append(cmds, flipMonitorCmd(item.monitor))
 		case key.Matches(msg, d.keymap.scale):
 			logrus.Debugf("List called with scale")
 			if !item.Editing() {

internal/tui/monitors_preview_pane.go

@@ -7,6 +7,7 @@ import (
 	"github.com/charmbracelet/bubbles/key"
 	tea "github.com/charmbracelet/bubbletea"
 	"github.com/charmbracelet/lipgloss"
+	"github.com/fiffeek/hyprdynamicmonitors/internal/utils"
 	"github.com/sirupsen/logrus"
 )
 
@@ -438,6 +439,9 @@ func (*MonitorsPreviewPane) drawMonitorLabel(isSelected bool, monitor *MonitorSp
 	if len(label) > 6 {
 		label = label[:6] // Truncate long names
 	}
+	if monitor.Flipped {
+		label = utils.Reverse(label)
+	}
 	if isSelected {
 		label = "*" + label
 	}
@@ -545,7 +549,7 @@ func (p *MonitorsPreviewPane) renderLegend() string {
 		coloredPattern := GetMonitorColorStyle(i).Render("██")
 		item := fmt.Sprintf("%s %s - %s, %s, %s, %s",
 			coloredPattern, monitor.Name, monitor.Mode(), monitor.PositionPretty(),
-			monitor.ScalePretty(), monitor.RotationPretty())
+			monitor.ScalePretty(), monitor.RotationPretty(false))
 
 		if i == p.selectedIndex {
 			item = SelectedMonitorStyle.Render("► " + item + " ◄")

internal/tui/root.go

@@ -347,6 +347,9 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	case ToggleMonitorVRRCommand:
 		logrus.Debug("Received a monitor vrr command")
 		cmds = append(cmds, m.monitorEditor.ToggleVRR(msg.MonitorID))
+	case FlipMonitorCommand:
+		logrus.Debug("Received a monitor flip command")
+		cmds = append(cmds, m.monitorEditor.FlipMonitor(msg.MonitorID))
 	case RotateMonitorCommand:
 		logrus.Debug("Received a monitor rotate command")
 		cmds = append(cmds, m.monitorEditor.RotateMonitor(msg.MonitorID))

internal/tui/root_test.go

@@ -69,6 +69,30 @@ func TestModel_Update_UserFlows(t *testing.T) {
 			},
 		},
 
+		{
+			name:         "rotate_flip",
+			monitorsData: defaultMonitorData,
+			runFor:       utils.JustPtr(500 * time.Millisecond),
+			steps: []step{
+				{
+					msg:                   tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'j'}},
+					expectOutputToContain: "► DP-1",
+				},
+				{
+					msg:                   tea.KeyMsg{Type: tea.KeyEnter},
+					expectOutputToContain: "EDITING",
+				},
+				{
+					msg:                   tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'r'}},
+					expectOutputToContain: "DP-1→",
+				},
+				{
+					msg:                   tea.KeyMsg{Type: tea.KeyRunes, Runes: []rune{'L'}},
+					expectOutputToContain: "1-PD→",
+				},
+			},
+		},
+
 		{
 			name:         "scale_open",
 			monitorsData: defaultMonitorData,