Command Palette Technical Specification
Overview
The command palette provides a searchable interface for quick access to keyboard actions, settings, and features. It’s triggered by long-pressing the settings key or via a configured shortcut.
Key Components
| Component | File | Purpose |
|---|
| CommandPalette | CommandPalette.kt | Main palette logic |
| CommandRegistry | CommandRegistry.kt | Available commands |
| PaletteView | CommandPaletteView.kt | UI rendering |
| SearchEngine | PaletteSearch.kt | Fuzzy search |
| Config | Config.kt | Palette settings |
Data Model
Command Definition
// CommandRegistry.kt
data class Command(
val id: String,
val displayName: String,
val description: String,
val category: CommandCategory,
val keywords: List<String>,
val action: () -> Unit,
val isEnabled: () -> Boolean = { true },
val icon: Int? = null
)
enum class CommandCategory {
TEXT, // Copy, paste, select
NAVIGATION, // Cursor, home, end
INPUT, // Layout, language, emoji
SETTINGS, // Toggles, preferences
CLIPBOARD // History, clear, pin
}
Command Registry
// CommandRegistry.kt
object CommandRegistry {
private val commands = mutableListOf<Command>()
init {
// Text actions
register(Command(
id = "copy",
displayName = "Copy",
description = "Copy selected text",
category = CommandCategory.TEXT,
keywords = listOf("copy", "clipboard", "selection"),
action = { inputConnection?.performContextMenuAction(android.R.id.copy) }
))
register(Command(
id = "paste",
displayName = "Paste",
description = "Paste from clipboard",
category = CommandCategory.TEXT,
keywords = listOf("paste", "clipboard", "insert"),
action = { inputConnection?.performContextMenuAction(android.R.id.paste) },
isEnabled = { clipboardManager.hasPrimaryClip() }
))
// Navigation actions
register(Command(
id = "home",
displayName = "Home",
description = "Jump to line start",
category = CommandCategory.NAVIGATION,
keywords = listOf("home", "start", "beginning", "line"),
action = { sendKeyEvent(KeyEvent.KEYCODE_MOVE_HOME) }
))
// ... 30+ more commands
}
}
Activation Flow
Long-press settings key (>500ms)
↓
Detect long press in Pointers.kt
↓
CommandPalette.show()
↓
PaletteView inflates overlay
↓
Focus search input
↓
User types search query
↓
PaletteSearch.search(query)
↓
Filter and rank results
↓
Display matched commands
↓
User taps command
↓
Execute command.action()
↓
CommandPalette.hide()
Search Implementation
Fuzzy Search
// PaletteSearch.kt
class PaletteSearch {
fun search(query: String, commands: List<Command>): List<SearchResult> {
if (query.isEmpty()) {
return getRecentCommands() + commands.sortedBy { it.category }
}
val normalizedQuery = query.lowercase()
return commands
.mapNotNull { cmd -> scoreCommand(cmd, normalizedQuery) }
.sortedByDescending { it.score }
}
private fun scoreCommand(cmd: Command, query: String): SearchResult? {
var score = 0
// Exact match in name
if (cmd.displayName.lowercase().contains(query)) {
score += 100
}
// Keyword match
cmd.keywords.forEach { keyword ->
if (keyword.contains(query)) {
score += 50
}
}
// Fuzzy match
val fuzzyScore = fuzzyMatch(cmd.displayName, query)
score += fuzzyScore
// Boost recent commands
if (isRecent(cmd.id)) {
score += 30
}
return if (score > 20) SearchResult(cmd, score) else null
}
private fun fuzzyMatch(text: String, query: String): Int {
// Levenshtein distance-based scoring
val distance = levenshteinDistance(text.lowercase(), query)
val maxLen = maxOf(text.length, query.length)
return ((1 - distance.toFloat() / maxLen) * 50).toInt()
}
}
UI Rendering
Palette View
// CommandPaletteView.kt
class CommandPaletteView : FrameLayout {
private lateinit var searchInput: EditText
private lateinit var resultsList: RecyclerView
private lateinit var categoryTabs: TabLayout
fun show() {
visibility = VISIBLE
searchInput.requestFocus()
showKeyboard()
// Show recent commands initially
displayResults(search.getRecentCommands())
}
private fun onSearchQueryChanged(query: String) {
val results = search.search(query, registry.getAllCommands())
displayResults(results)
}
private fun onCommandSelected(command: Command) {
if (command.isEnabled()) {
recordRecent(command.id)
hide()
command.action()
}
}
}
Layout Structure
┌────────────────────────────────────────┐
│ ┌────────────────────────────────────┐ │
│ │ 🔍 Search actions... X│ │ ← Search input
│ └────────────────────────────────────┘ │
├────────────────────────────────────────┤
│ [All] [Text] [Nav] [Input] [Settings] │ ← Category tabs
├────────────────────────────────────────┤
│ ┌────────────────────────────────────┐ │
│ │ 📋 Copy Copy selected text │ │ ← Command item
│ │ ✂️ Cut Cut selected text │ │
│ │ 📄 Paste Paste from clipbo..│ │
│ │ ☑️ Select All Select all text │ │
│ └────────────────────────────────────┘ │
└────────────────────────────────────────┘
Recent Commands
// CommandPalette.kt
private val recentCommands = LinkedHashMap<String, Long>(16, 0.75f, true)
fun recordRecent(commandId: String) {
recentCommands[commandId] = System.currentTimeMillis()
// Keep max 10 recent
while (recentCommands.size > 10) {
recentCommands.remove(recentCommands.keys.first())
}
saveRecentToPrefs()
}
fun getRecentCommands(): List<Command> {
return recentCommands.keys
.reversed()
.take(5)
.mapNotNull { registry.getCommand(it) }
}
Customization
Favorites
// CommandPalette.kt
private val favoriteCommands = mutableSetOf<String>()
fun toggleFavorite(commandId: String) {
if (favoriteCommands.contains(commandId)) {
favoriteCommands.remove(commandId)
} else {
favoriteCommands.add(commandId)
}
saveFavoritesToPrefs()
}
Hidden Commands
// CommandPalette.kt
private val hiddenCommands = mutableSetOf<String>()
fun getVisibleCommands(): List<Command> {
return registry.getAllCommands()
.filter { !hiddenCommands.contains(it.id) }
}
Configuration
| Setting | Key | Default | Description |
|---|
| Trigger | palette_trigger | ”long_press_settings” | Activation method |
| Show Recent | palette_show_recent | true | Show recent commands |
| Show Categories | palette_show_categories | true | Show category tabs |
| Max Recent | palette_max_recent | 5 | Number of recent items |
