Snippets for keyboard input (#368)

* Add a sample code for Keyboard Shortcuts Helper

* Add a sample code for keyboard actions

* Fix the issue on casting a Context object into Activity

Author: chikoski

compose/snippets/src/main/java/com/example/compose/snippets/touchinput/keyboardinput/KeyboardShortcutsHelper.kt

@@ -0,0 +1,116 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.compose.snippets.touchinput.keyboardinput
+
+import android.app.Activity
+import android.os.Build
+import android.os.Bundle
+import android.view.KeyEvent
+import android.view.KeyboardShortcutGroup
+import android.view.KeyboardShortcutInfo
+import android.view.Menu
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
+import androidx.annotation.RequiresApi
+import androidx.compose.material3.Button
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.ui.platform.LocalContext
+
+class MainActivity : ComponentActivity() {
+    // Activity codes such as overridden onStart method.
+
+    @RequiresApi(Build.VERSION_CODES.N)
+    // [START android_compose_keyboard_shortcuts_helper]
+    override fun onProvideKeyboardShortcuts(
+        data: MutableList<KeyboardShortcutGroup>?,
+        menu: Menu?,
+        deviceId: Int
+    ) {
+        val shortcutGroup =
+            KeyboardShortcutGroup(
+                "Cursor movement",
+                listOf(
+                    KeyboardShortcutInfo("Up", KeyEvent.KEYCODE_P, KeyEvent.META_CTRL_ON),
+                    KeyboardShortcutInfo("Down", KeyEvent.KEYCODE_N, KeyEvent.META_CTRL_ON),
+                    KeyboardShortcutInfo("Forward", KeyEvent.KEYCODE_F, KeyEvent.META_CTRL_ON),
+                    KeyboardShortcutInfo("Backward", KeyEvent.KEYCODE_B, KeyEvent.META_CTRL_ON),
+                )
+            )
+        data?.add(shortcutGroup)
+    }
+    // [END android_compose_keyboard_shortcuts_helper]
+}
+
+class AnotherActivity : ComponentActivity() {
+
+    @RequiresApi(Build.VERSION_CODES.N)
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        enableEdgeToEdge()
+        setContent {
+            MaterialTheme {
+                // [START android_compose_keyboard_shortcuts_helper_request]
+                val activity = LocalContext.current as? Activity
+
+                Button(
+                    onClick = {
+                        activity?.requestShowKeyboardShortcuts()
+                    }
+                ) {
+                    Text(text = "Show keyboard shortcuts")
+                }
+                // [END android_compose_keyboard_shortcuts_helper_request]
+            }
+        }
+    }
+
+    @RequiresApi(Build.VERSION_CODES.N)
+    // [START android_compose_keyboard_shortcuts_helper_with_groups]
+    override fun onProvideKeyboardShortcuts(
+        data: MutableList<KeyboardShortcutGroup>?,
+        menu: Menu?,
+        deviceId: Int
+    ) {
+        val cursorMovement = KeyboardShortcutGroup(
+            "Cursor movement",
+            listOf(
+                KeyboardShortcutInfo("Up", KeyEvent.KEYCODE_P, KeyEvent.META_CTRL_ON),
+                KeyboardShortcutInfo("Down", KeyEvent.KEYCODE_N, KeyEvent.META_CTRL_ON),
+                KeyboardShortcutInfo("Forward", KeyEvent.KEYCODE_F, KeyEvent.META_CTRL_ON),
+                KeyboardShortcutInfo("Backward", KeyEvent.KEYCODE_B, KeyEvent.META_CTRL_ON),
+            )
+        )
+
+        val messageEdit = KeyboardShortcutGroup(
+            "Message editing",
+            listOf(
+                KeyboardShortcutInfo("Select All", KeyEvent.KEYCODE_A, KeyEvent.META_CTRL_ON),
+                KeyboardShortcutInfo(
+                    "Send a message",
+                    KeyEvent.KEYCODE_ENTER,
+                    KeyEvent.META_SHIFT_ON
+                )
+            )
+        )
+
+        data?.add(cursorMovement)
+        data?.add(messageEdit)
+    }
+    // [END android_compose_keyboard_shortcuts_helper_with_groups]
+}