feat(android): Add the keyboard height code

README.md

@@ -27,3 +27,7 @@ Thanks to [ekasetiawans](https://github.com/ekasetiawans) for [flutter_backgroun
 was essentially the blueprint for the service and background service APIs. They were reimplemented
 to allow the root isolate to pass some additional data to the service, which `flutter_background_service`
 did not support.
+
+Thanks to [nschairer](https://github.com/nschairer) for [flutter_keyboard_height](https://github.com/nschairer/keyboard_height_plugin), which was the base for keeping track of the keyboard height.
+Due to having an issue with the height calculation if the Android device uses gesture navigation, I
+[forked the package](https://git.polynom.me/moxxy/keyboard_height_plugin) and modified the height calculation.

android/src/main/kotlin/org/moxxy/moxxy_native/Constants.kt

@@ -2,6 +2,9 @@ package org.moxxy.moxxy_native
 
 const val TAG = "moxxy_native"
 
+// The event channel name for the keyboard height
+const val KEYBOARD_HEIGHT_EVENT_CHANNEL_NAME = "org.moxxy.moxxyv2/notification_stream"
+
 // The size of buffers to use for various operations
 const val BUFFER_SIZE = 4096
 

android/src/main/kotlin/org/moxxy/moxxy_native/MoxxyNativePlugin.kt

@@ -29,6 +29,7 @@ import org.moxxy.moxxy_native.notifications.NotificationsImplementation
 import org.moxxy.moxxy_native.picker.FilePickerType
 import org.moxxy.moxxy_native.picker.MoxxyPickerApi
 import org.moxxy.moxxy_native.picker.PickerResultListener
+import org.moxxy.moxxy_native.platform.KeyboardStreamHandler
 import org.moxxy.moxxy_native.platform.MoxxyPlatformApi
 import org.moxxy.moxxy_native.platform.PlatformImplementation
 import org.moxxy.moxxy_native.service.BackgroundService
@@ -102,6 +103,10 @@ class MoxxyNativePlugin : FlutterPlugin, ActivityAware, ServiceAware, BroadcastR
             IntentFilter(SERVICE_FOREGROUND_METHOD_CHANNEL_KEY),
         )
 
+        // Special handling for the keyboard height
+        val keyboardChannel = EventChannel(flutterPluginBinding.getBinaryMessenger(), KEYBOARD_HEIGHT_EVENT_CHANNEL_NAME)
+        keyboardChannel?.setStreamHandler(KeyboardStreamHandler)
+
         // Register the picker handler
         pickerListener = PickerResultListener(context!!)
         Log.d(TAG, "Attached to engine")
@@ -118,20 +123,24 @@ class MoxxyNativePlugin : FlutterPlugin, ActivityAware, ServiceAware, BroadcastR
     override fun onAttachedToActivity(binding: ActivityPluginBinding) {
         activity = binding.activity
         binding.addActivityResultListener(pickerListener)
+        KeyboardStreamHandler.activity = activity
         Log.d(TAG, "Attached to activity")
     }
 
     override fun onDetachedFromActivityForConfigChanges() {
         activity = null
+        KeyboardStreamHandler.activity = null
         Log.d(TAG, "Detached from activity")
     }
 
     override fun onReattachedToActivityForConfigChanges(binding: ActivityPluginBinding) {
         activity = binding.activity
+        KeyboardStreamHandler.activity = activity
     }
 
     override fun onDetachedFromActivity() {
         activity = null
+        KeyboardStreamHandler.activity = null
         Log.d(TAG, "Detached from activity")
     }
 

android/src/main/kotlin/org/moxxy/moxxy_native/notifications/NotificationReceiver.kt

@@ -164,7 +164,7 @@ class NotificationReceiver : BroadcastReceiver() {
         }
     }
 
-    fun handleTap(context: Context, intent: Intent) {
+    private fun handleTap(context: Context, intent: Intent) {
         MoxxyEventChannels.notificationEventSink?.success(
             NotificationEvent(
                 intent.getLongExtra(NOTIFICATION_EXTRA_ID_KEY, -1),

android/src/main/kotlin/org/moxxy/moxxy_native/platform/KeyboardStreamHandler.kt

@@ -0,0 +1,73 @@
+package org.moxxy.moxxy_native.platform
+
+import android.app.Activity
+import android.graphics.Rect
+import android.util.Log
+import android.view.View
+import android.view.ViewTreeObserver
+import androidx.core.view.ViewCompat
+import androidx.core.view.WindowInsetsCompat
+import io.flutter.plugin.common.EventChannel
+import org.moxxy.moxxy_native.MoxxyEventChannels
+import org.moxxy.moxxy_native.TAG
+
+object KeyboardStreamHandler : EventChannel.StreamHandler {
+    // The currently active activity. Set by @MoxxyNativePlugin.
+    var activity: Activity? = null
+
+    // The current bottom inset.
+    private var bottomInset: Int = 0
+
+    // The current event sink to use for sending events to the UI.
+    private var sink: EventChannel.EventSink? = null
+
+    private fun handleKeyboardHeightCheck(rootView: View?) {
+        rootView?.viewTreeObserver?.addOnGlobalLayoutListener(object : ViewTreeObserver.OnGlobalLayoutListener {
+            override fun onGlobalLayout() {
+                val r = Rect()
+                rootView.getWindowVisibleDisplayFrame(r)
+
+                val screenHeight = rootView.height
+                // Also subtract the height of the bottom inset as the SafeArea with "bottom: false"
+                // allows us to draw under the bottom system bar, if it is there.
+                val keypadHeight = screenHeight - r.bottom - bottomInset
+
+                val displayMetrics = activity?.resources?.displayMetrics
+                val logicalKeypadHeight = keypadHeight / (displayMetrics?.density ?: 1f)
+
+                if (keypadHeight > screenHeight * 0.15) {
+                    sink?.success(logicalKeypadHeight.toDouble())
+                } else {
+                    sink?.success(0.0)
+                }
+            }
+        })
+    }
+
+    override fun onListen(arguments: Any?, events: EventChannel.EventSink?) {
+        // "register" the event sink
+        sink = events
+
+        val rootView = activity?.window?.decorView?.rootView
+        handleKeyboardHeightCheck(rootView)
+
+        if (rootView != null) {
+            ViewCompat.setOnApplyWindowInsetsListener(rootView!!) { _, windowInsets ->
+                val insets = windowInsets.getInsets(WindowInsetsCompat.Type.systemBars())
+                val triggerEvent = bottomInset != insets.bottom
+                bottomInset = insets.bottom
+
+                // Notify in case the inset changed
+                if (triggerEvent) handleKeyboardHeightCheck(rootView)
+
+                WindowInsetsCompat.CONSUMED
+            }
+        }
+        Log.d(TAG, "KeyboardStreamHandler: Attached stream")
+    }
+
+    override fun onCancel(arguments: Any?) {
+        MoxxyEventChannels.notificationEventSink = null
+        Log.d(TAG, "KeyboardStreamHandler: Detached stream")
+    }
+}

example/lib/main.dart

@@ -1,6 +1,5 @@
 // ignore_for_file: avoid_print
 import 'dart:io';
-import 'dart:typed_data';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:get_it/get_it.dart';
@@ -51,6 +50,19 @@ class TestEvent extends BackgroundEvent {
 class MyAppState extends State<MyApp> {
   String? imagePath;
 
+  @override
+  void initState() {
+    super.initState();
+
+    const EventChannel('org.moxxy.moxxyv2/notification_stream')
+        .receiveBroadcastStream()
+        .listen(
+      (event) {
+        print('Keyboard height: ${event as double}');
+      },
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -221,6 +233,7 @@ class MyAppState extends State<MyApp> {
               },
               child: const Text('Share some text'),
             ),
+            const TextField(),
           ],
         ),
       ),