feat(core): implements KeyValue and KeyModifier

Ref: https://github.com/rime/librime/blob/1.11.2/src/rime/key_table.h

app/src/main/java/com/osfans/trime/core/KeyModifier.kt

@@ -0,0 +1,103 @@
+/*
+ * SPDX-FileCopyrightText: 2015 - 2024 Rime community
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package com.osfans.trime.core
+
+import android.view.KeyEvent
+import splitties.bitflags.hasFlag
+
+/**
+ * translated from
+ * [librime/key_table.h](https://github.com/rime/librime/blob/1.11.2/src/rime/key_table.h)
+ */
+enum class KeyModifier(
+    val modifier: UInt,
+) {
+    None(0u),
+    Shift(1u shl 0),
+    Lock(1u shl 1), // CapsLock
+    Control(1u shl 2),
+    Mod1(1u shl 3),
+    Alt(Mod1),
+    Mod2(1u shl 4), // NumLock
+    Mod3(1u shl 5),
+    Mod4(1u shl 6),
+    Mod5(1u shl 7),
+    Button1(1u shl 8),
+    Button2(1u shl 9),
+    Button3(1u shl 10),
+    Button4(1u shl 11),
+    Button5(1u shl 12),
+    Handled(1u shl 24),
+    Forward(1u shl 25),
+    Ignored(Forward),
+    Super(1u shl 26),
+    Hyper(1u shl 27),
+    Meta(1u shl 28),
+    Release(1u shl 30),
+    Modifier(0x5f001fffu),
+    ;
+
+    constructor(other: KeyModifier) : this(other.modifier)
+
+    infix fun or(other: KeyModifier): UInt = modifier or other.modifier
+
+    infix fun or(other: UInt): UInt = modifier or other
+}
+
+operator fun UInt.plus(other: KeyModifier) = or(other.modifier)
+
+operator fun UInt.minus(other: KeyModifier) = and(other.modifier.inv())
+
+@JvmInline
+value class KeyModifiers(
+    val modifiers: UInt,
+) {
+    constructor(vararg modifiers: KeyModifier) : this(mergeModifiers(modifiers))
+
+    fun has(modifier: KeyModifier) = modifiers.hasFlag(modifier.modifier)
+
+    val alt get() = has(KeyModifier.Alt)
+    val ctrl get() = has(KeyModifier.Control)
+    val shift get() = has(KeyModifier.Shift)
+    val meta get() = has(KeyModifier.Meta)
+    val capsLock get() = has(KeyModifier.Lock)
+
+    val metaState: Int get() {
+        var metaState = 0
+        if (alt) metaState = KeyEvent.META_ALT_ON or KeyEvent.META_ALT_LEFT_ON
+        if (ctrl) metaState = metaState or KeyEvent.META_CTRL_ON or KeyEvent.META_CTRL_LEFT_ON
+        if (shift) metaState = metaState or KeyEvent.META_SHIFT_ON or KeyEvent.META_SHIFT_LEFT_ON
+        if (meta) metaState = metaState or KeyEvent.META_META_ON or KeyEvent.META_META_LEFT_ON
+        if (capsLock) metaState = metaState or KeyEvent.META_CAPS_LOCK_ON
+        return metaState
+    }
+
+    fun toInt() = modifiers.toInt()
+
+    companion object {
+        val Empty = KeyModifiers(0u)
+
+        fun of(v: Int) = KeyModifiers(v.toUInt())
+
+        fun fromKeyEvent(event: KeyEvent): KeyModifiers {
+            var states = KeyModifier.None.modifier
+            event.apply {
+                if (action == KeyEvent.ACTION_UP) {
+                    states += KeyModifier.Release
+                } else {
+                    if (isAltPressed) states += KeyModifier.Alt
+                    if (isCtrlPressed) states += KeyModifier.Control
+                    if (isShiftPressed) states += KeyModifier.Shift
+                    if (isCapsLockOn) states += KeyModifier.Lock
+                    if (isMetaPressed) states += KeyModifier.Meta
+                }
+            }
+            return KeyModifiers(states)
+        }
+
+        fun mergeModifiers(arr: Array<out KeyModifier>): UInt = arr.fold(KeyModifier.None.modifier) { acc, it -> acc or it.modifier }
+    }
+}

app/src/main/java/com/osfans/trime/core/KeyValue.kt

@@ -0,0 +1,21 @@
+/*
+ * SPDX-FileCopyrightText: 2015 - 2024 Rime community
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+package com.osfans.trime.core
+
+import android.view.KeyEvent
+
+@JvmInline
+value class KeyValue(
+    val value: Int,
+) {
+    val keyCode get() = RimeKeyMapping.valToKeyCode(value)
+
+    override fun toString() = "0x" + value.toString(16).padStart(4, '0')
+
+    companion object {
+        fun fromKeyEvent(event: KeyEvent) = KeyValue(RimeKeyMapping.keyCodeToVal(event.keyCode))
+    }
+}