Add keyboard shortcuts

app/src/main/java/com/capyreader/app/MainActivity.kt

@@ -2,10 +2,14 @@ package com.capyreader.app
 
 import android.content.Intent
 import android.os.Bundle
+import android.view.KeyboardShortcutGroup
+import android.view.KeyboardShortcutInfo
+import android.view.Menu
 import androidx.activity.compose.setContent
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
+import com.capyreader.app.keyboard.KeyboardShortcutManager
 import com.capyreader.app.notifications.NotificationHelper
 import com.capyreader.app.preferences.AppPreferences
 import com.capyreader.app.ui.App
@@ -37,6 +41,23 @@ class MainActivity : BaseActivity() {
         pendingArticleID = NotificationHelper.openFromIntent(intent, appPreferences = appPreferences)
     }
 
+    override fun onProvideKeyboardShortcuts(
+        data: MutableList<KeyboardShortcutGroup>?,
+        menu: Menu?,
+        deviceId: Int
+    ) {
+        super.onProvideKeyboardShortcuts(data, menu, deviceId)
+        val manager = get<KeyboardShortcutManager>()
+        val shortcuts = manager.effectiveBindings().flatMap { (action, keys) ->
+            keys.map { key ->
+                KeyboardShortcutInfo(getString(action.labelRes), key.keyCode, key.meta)
+            }
+        }
+        data?.add(
+            KeyboardShortcutGroup(getString(R.string.shortcuts_group_title), shortcuts)
+        )
+    }
+
     private fun startDestination(): Route {
         val appPreferences = get<AppPreferences>()
 

app/src/main/java/com/capyreader/app/keyboard/KeyboardShortcutManager.kt

@@ -0,0 +1,56 @@
+package com.capyreader.app.keyboard
+
+import com.jocmp.capy.preferences.Preference
+import com.jocmp.capy.preferences.getAndSet
+
+class KeyboardShortcutManager(
+    private val overridesPreference: Preference<ShortcutOverrides>,
+) {
+    fun resolve(keyCode: Int, meta: Int): ShortcutAction? {
+        val key = ShortcutKey(keyCode = keyCode, meta = meta)
+        val reverseLookup = buildReverseLookup()
+        return reverseLookup[key]
+    }
+
+    fun effectiveBindings(): Map<ShortcutAction, List<ShortcutKey>> {
+        val overrides = overridesPreference.get().bindings
+        return ShortcutAction.entries.associateWith { action ->
+            overrides[action] ?: action.defaultKeys
+        }
+    }
+
+    fun updateBinding(action: ShortcutAction, keys: List<ShortcutKey>) {
+        overridesPreference.getAndSet { current ->
+            current.copy(bindings = current.bindings + (action to keys))
+        }
+    }
+
+    fun resetBinding(action: ShortcutAction) {
+        overridesPreference.getAndSet { current ->
+            current.copy(bindings = current.bindings - action)
+        }
+    }
+
+    fun resetAll() {
+        overridesPreference.set(ShortcutOverrides())
+    }
+
+    fun findConflict(key: ShortcutKey, excludeAction: ShortcutAction): ShortcutAction? {
+        return effectiveBindings()
+            .filterKeys { it != excludeAction }
+            .entries
+            .firstOrNull { (_, keys) -> key in keys }
+            ?.key
+    }
+
+    private fun buildReverseLookup(): Map<ShortcutKey, ShortcutAction> {
+        val bindings = effectiveBindings()
+        val lookup = mutableMapOf<ShortcutKey, ShortcutAction>()
+        bindings.forEach { (action, keys) ->
+            keys.forEach { key ->
+                lookup[key] = action
+            }
+        }
+        return lookup
+    }
+}

app/src/main/java/com/capyreader/app/keyboard/ShortcutAction.kt

@@ -0,0 +1,85 @@
+package com.capyreader.app.keyboard
+
+import android.view.KeyEvent
+import androidx.annotation.StringRes
+import com.capyreader.app.R
+import kotlinx.serialization.Serializable
+
+@Serializable
+enum class ShortcutAction(
+    @StringRes val labelRes: Int,
+    val defaultKeys: List<ShortcutKey>,
+) {
+    NEXT_ARTICLE(
+        labelRes = R.string.shortcut_next_article,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_J),
+        ),
+    ),
+    PREVIOUS_ARTICLE(
+        labelRes = R.string.shortcut_previous_article,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_K),
+        ),
+    ),
+    TOGGLE_STAR(
+        labelRes = R.string.shortcut_toggle_star,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_S),
+        ),
+    ),
+    TOGGLE_READ(
+        labelRes = R.string.shortcut_toggle_read,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_M),
+        ),
+    ),
+    TOGGLE_FULL_CONTENT(
+        labelRes = R.string.shortcut_toggle_full_content,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_C),
+        ),
+    ),
+    OPEN_IN_BROWSER(
+        labelRes = R.string.shortcut_open_in_browser,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_V),
+        ),
+    ),
+    REFRESH(
+        labelRes = R.string.shortcut_refresh,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_R),
+        ),
+    ),
+    GO_BACK(
+        labelRes = R.string.shortcut_go_back,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_ESCAPE),
+        ),
+    ),
+    MARK_ALL_READ(
+        labelRes = R.string.shortcut_mark_all_read,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_A, meta = KeyEvent.META_SHIFT_ON),
+        ),
+    ),
+    FOCUS_SEARCH(
+        labelRes = R.string.shortcut_focus_search,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_SLASH),
+        ),
+    ),
+    TOGGLE_FULLSCREEN(
+        labelRes = R.string.shortcut_toggle_fullscreen,
+        defaultKeys = listOf(
+            ShortcutKey(KeyEvent.KEYCODE_F, meta = KeyEvent.META_SHIFT_ON),
+        ),
+    );
+
+    fun isCharacterBound(): Boolean {
+        return defaultKeys.any { key ->
+            key.meta == 0 && key.keyCode in KeyEvent.KEYCODE_A..KeyEvent.KEYCODE_Z
+        }
+    }
+}

app/src/main/java/com/capyreader/app/keyboard/ShortcutKey.kt

@@ -0,0 +1,66 @@
+package com.capyreader.app.keyboard
+
+import android.view.KeyEvent
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class ShortcutKey(
+    val keyCode: Int,
+    val meta: Int = 0,
+) {
+    fun label(): String {
+        val parts = mutableListOf<String>()
+
+        if (meta and KeyEvent.META_CTRL_ON != 0) parts.add("Ctrl")
+        if (meta and KeyEvent.META_ALT_ON != 0) parts.add("Alt")
+        if (meta and KeyEvent.META_SHIFT_ON != 0) parts.add("Shift")
+        if (meta and KeyEvent.META_META_ON != 0) parts.add("Meta")
+
+        parts.add(keyCodeLabel(keyCode))
+
+        return parts.joinToString("+")
+    }
+
+    companion object {
+        private fun keyCodeLabel(keyCode: Int): String {
+            return when (keyCode) {
+                KeyEvent.KEYCODE_DPAD_UP -> "Up"
+                KeyEvent.KEYCODE_DPAD_DOWN -> "Down"
+                KeyEvent.KEYCODE_DPAD_LEFT -> "Left"
+                KeyEvent.KEYCODE_DPAD_RIGHT -> "Right"
+                KeyEvent.KEYCODE_ENTER -> "Enter"
+                KeyEvent.KEYCODE_SPACE -> "Space"
+                KeyEvent.KEYCODE_ESCAPE -> "Esc"
+                KeyEvent.KEYCODE_DEL -> "Backspace"
+                KeyEvent.KEYCODE_FORWARD_DEL -> "Delete"
+                KeyEvent.KEYCODE_TAB -> "Tab"
+                else -> KeyEvent.keyCodeToString(keyCode)
+                    .removePrefix("KEYCODE_")
+                    .lowercase()
+                    .replaceFirstChar { it.uppercase() }
+            }
+        }
+
+        fun isModifierOnly(keyCode: Int): Boolean {
+            return keyCode in listOf(
+                KeyEvent.KEYCODE_SHIFT_LEFT,
+                KeyEvent.KEYCODE_SHIFT_RIGHT,
+                KeyEvent.KEYCODE_CTRL_LEFT,
+                KeyEvent.KEYCODE_CTRL_RIGHT,
+                KeyEvent.KEYCODE_ALT_LEFT,
+                KeyEvent.KEYCODE_ALT_RIGHT,
+                KeyEvent.KEYCODE_META_LEFT,
+                KeyEvent.KEYCODE_META_RIGHT,
+            )
+        }
+
+        fun metaState(event: KeyEvent): Int {
+            var meta = 0
+            if (event.isCtrlPressed) meta = meta or KeyEvent.META_CTRL_ON
+            if (event.isAltPressed) meta = meta or KeyEvent.META_ALT_ON
+            if (event.isShiftPressed) meta = meta or KeyEvent.META_SHIFT_ON
+            if (event.isMetaPressed) meta = meta or KeyEvent.META_META_ON
+            return meta
+        }
+    }
+}

app/src/main/java/com/capyreader/app/keyboard/ShortcutOverrides.kt

@@ -0,0 +1,8 @@
+package com.capyreader.app.keyboard
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class ShortcutOverrides(
+    val bindings: Map<ShortcutAction, List<ShortcutKey>> = emptyMap()
+)

app/src/main/java/com/capyreader/app/preferences/AppPreferences.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import androidx.preference.PreferenceManager
 import com.capyreader.app.common.FeedGroup
 import com.capyreader.app.common.ImagePreview
+import com.capyreader.app.keyboard.ShortcutOverrides
 import com.capyreader.app.refresher.RefreshInterval
 import com.capyreader.app.ui.articles.ArticleListFontScale
 import com.capyreader.app.ui.articles.DefaultPaneExpansionIndex
@@ -82,6 +83,20 @@ class AppPreferences(context: Context) {
     val badgeStyle: Preference<BadgeStyle>
         get() = preferenceStore.getEnum("badge_style", BadgeStyle.default)
 
+    val shortcutOverrides: Preference<ShortcutOverrides>
+        get() = preferenceStore.getObject(
+            key = "keyboard_shortcut_overrides",
+            defaultValue = ShortcutOverrides(),
+            serializer = { Json.encodeToString(it) },
+            deserializer = {
+                try {
+                    Json.decodeFromString(it)
+                } catch (e: Throwable) {
+                    ShortcutOverrides()
+                }
+            }
+        )
+
     fun clearAll() {
         preferenceStore.clearAll()
     }

app/src/main/java/com/capyreader/app/ui/articles/ArticleList.kt

@@ -35,6 +35,7 @@ fun ArticleList(
     onMarkAllRead: (range: MarkRead) -> Unit = {},
     refreshingAll: Boolean,
     dimReadArticles: Boolean = true,
+    keyboardNavigated: Boolean = false,
 ) {
     val articleOptions = rememberArticleOptions().copy(
         dim = dimReadArticles,
@@ -58,6 +59,7 @@ fun ArticleList(
                                 article = item,
                                 index = index,
                                 selected = selectedArticleKey == item.id,
+                                keyboardNavigated = keyboardNavigated,
                                 onSelect = {
                                     onSelect(it)
                                 },

app/src/main/java/com/capyreader/app/ui/articles/ArticleRow.kt

@@ -3,6 +3,7 @@ package com.capyreader.app.ui.articles
 import android.content.res.Configuration
 import androidx.compose.foundation.ExperimentalFoundationApi
 import androidx.compose.foundation.background
+import androidx.compose.foundation.border
 import androidx.compose.foundation.combinedClickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -95,6 +96,7 @@ fun ArticleRow(
     onMarkAllRead: (range: MarkRead) -> Unit = {},
     currentTime: LocalDateTime,
     options: ArticleRowOptions = ArticleRowOptions(),
+    keyboardNavigated: Boolean = false,
 ) {
     val imageURL = article.imageURL
     val isMonochrome = LocalAppTheme.current.value == AppTheme.MONOCHROME
@@ -125,6 +127,7 @@ fun ArticleRow(
             onClick = { onSelect(article.id) },
             onLongClick = openArticleMenu,
             article = article,
+            showBorder = selected && keyboardNavigated,
         ) {
             ArticleListItem(
                 headlineContent = {
@@ -415,11 +418,22 @@ private fun ArticleBox(
     onClick: () -> Unit,
     onLongClick: () -> Unit,
     article: Article,
+    showBorder: Boolean,
     content: @Composable () -> Unit
 ) {
     ArticleRowSwipeBox(article) {
-        Box(
+        val borderModifier = if (showBorder) {
+            Modifier.border(
+                width = 2.dp,
+                color = colorScheme.primary,
+                shape = RoundedCornerShape(4.dp),
+            )
+        } else {
             Modifier
+        }
+
+        Box(
+            borderModifier
                 .combinedClickable(
                     onClick = onClick,
                     onLongClick = onLongClick,