fix: perform haptic feedback on cursor move (#228)

* fix: perform haptic feedback on cursor control

This uses `HapticFeedbackConstants.TEXT_HANDLE_MOVE`, which may not work on all devices.

See: #222

* fix: bump `HANDLE_MOVE_MIN_MS` to 35ms

Less buzzing when swiping quickly on some devices.

Author: naveensingh

app/src/main/kotlin/org/fossify/keyboard/services/SimpleKeyboardIME.kt

@@ -417,15 +417,20 @@ class SimpleKeyboardIME : InputMethodService(), OnKeyboardActionListener, Shared
     }
 
     private fun moveCursor(moveRight: Boolean) {
-        val extractedText = currentInputConnection?.getExtractedText(ExtractedTextRequest(), 0) ?: return
-        var newCursorPosition = extractedText.selectionStart
-        newCursorPosition = if (moveRight) {
-            newCursorPosition + 1
+        val inputConnection = currentInputConnection
+        val extractedText = inputConnection.getExtractedText(ExtractedTextRequest(), 0) ?: return
+        val text = extractedText.text ?: return
+        val oldPos = extractedText.selectionStart
+        val newPos = if (moveRight) {
+            oldPos + 1
         } else {
-            newCursorPosition - 1
-        }
+            oldPos - 1
+        }.coerceIn(0, text.length)
 
-        currentInputConnection?.setSelection(newCursorPosition, newCursorPosition)
+        if (newPos != oldPos) {
+            inputConnection?.setSelection(newPos, newPos)
+            keyboardView?.performHapticHandleMove()
+        }
     }
 
     private fun getImeOptionsActionId(): Int {

app/src/main/kotlin/org/fossify/keyboard/views/MyKeyboardView.kt

@@ -14,6 +14,7 @@ import android.os.Build
 import android.os.Handler
 import android.os.Looper
 import android.os.Message
+import android.os.SystemClock
 import android.util.AttributeSet
 import android.util.TypedValue
 import android.view.*
@@ -33,6 +34,7 @@ import androidx.emoji2.text.EmojiCompat.EMOJI_SUPPORTED
 import androidx.recyclerview.widget.GridLayoutManager.SpanSizeLookup
 import org.fossify.commons.extensions.*
 import org.fossify.commons.helpers.ensureBackgroundThread
+import org.fossify.commons.helpers.isOreoMr1Plus
 import org.fossify.commons.helpers.isPiePlus
 import org.fossify.keyboard.R
 import org.fossify.keyboard.activities.ManageClipboardItemsActivity
@@ -143,6 +145,7 @@ class MyKeyboardView @JvmOverloads constructor(
     private var mTopSmallNumberMarginHeight = 0f
     private val mSpaceMoveThreshold: Int
     private var ignoreTouches = false
+    private var lastHandleMoveAt = 0L
 
     private var mKeyBackground: Drawable? = null
     private var mShowKeyBorders: Boolean = false
@@ -185,6 +188,7 @@ class MyKeyboardView @JvmOverloads constructor(
         private const val REPEAT_INTERVAL = 50 // ~20 keys per second
         private const val REPEAT_START_DELAY = 400
         private val LONGPRESS_TIMEOUT = ViewConfiguration.getLongPressTimeout()
+        private const val HANDLE_MOVE_MIN_MS = 35L
     }
 
     init {
@@ -491,6 +495,20 @@ class MyKeyboardView @JvmOverloads constructor(
         }
     }
 
+    fun performHapticHandleMove() {
+        if (!context.config.vibrateOnKeypress) return
+        val now = SystemClock.uptimeMillis()
+        if (now - lastHandleMoveAt < HANDLE_MOVE_MIN_MS) return
+        lastHandleMoveAt = now
+        if (isOreoMr1Plus()) {
+            @Suppress("DEPRECATION")
+            performHapticFeedback(
+                HapticFeedbackConstants.TEXT_HANDLE_MOVE,
+                HapticFeedbackConstants.FLAG_IGNORE_GLOBAL_SETTING
+            )
+        }
+    }
+
     /**
      * Sets the state of the shift key of the keyboard, if any.
      * @param shifted whether or not to enable the state of the shift key