ADFA-3122 | Fix editor viewport and buffer persistence on configuration change (#1066)

* fix(editor): preserve scroll position and file timestamps on configuration change
Ensure cursor visibility after layout changes and update file timestamps after saving.

* fix: Make fileTimestamps thread-safe

Author: jatezzz

app/src/main/java/com/itsaky/androidide/activities/editor/EditorHandlerActivity.kt

@@ -18,6 +18,7 @@
 package com.itsaky.androidide.activities.editor
 
 import android.content.Intent
+import android.content.res.Configuration
 import android.os.Bundle
 import android.text.TextUtils
 import android.util.Log
@@ -26,6 +27,7 @@ import android.view.ViewGroup.LayoutParams
 import androidx.collection.MutableIntObjectMap
 import androidx.core.content.res.ResourcesCompat
 import androidx.core.view.GravityCompat
+import androidx.core.view.doOnNextLayout
 import androidx.lifecycle.lifecycleScope
 import com.blankj.utilcode.util.ImageUtils
 import com.google.android.material.tabs.TabLayout
@@ -79,6 +81,7 @@ import org.adfa.constants.CONTENT_KEY
 import org.greenrobot.eventbus.Subscribe
 import org.greenrobot.eventbus.ThreadMode
 import java.io.File
+import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.CopyOnWriteArrayList
 import java.util.concurrent.atomic.AtomicBoolean
 import java.util.function.Consumer
@@ -100,7 +103,7 @@ open class EditorHandlerActivity :
 
 	protected val isOpenedFilesSaved = AtomicBoolean(false)
 
-	private val fileTimestamps = mutableMapOf<String, Long>()
+	private val fileTimestamps = ConcurrentHashMap<String, Long>()
 
 	private val pluginTabIndices = mutableMapOf<String, Int>()
 	private val tabIndexToPluginId = mutableMapOf<Int, String>()
@@ -704,6 +707,16 @@ open class EditorHandlerActivity :
 		}
 	}
 
+	override fun onConfigurationChanged(newConfig: Configuration) {
+		super.onConfigurationChanged(newConfig)
+
+		getCurrentEditor()?.editor?.apply {
+			doOnNextLayout {
+				cursor?.let { c -> ensurePositionVisible(c.leftLine, c.leftColumn, true) }
+			}
+		}
+	}
+
 	private suspend fun saveResultInternal(
 		index: Int,
 		result: SaveResult,
@@ -723,6 +736,10 @@ open class EditorHandlerActivity :
 				return false
 			}
 
+			frag.file?.let { savedFile ->
+				fileTimestamps[savedFile.absolutePath] = savedFile.lastModified()
+			}
+
 			val isGradle = fileName.endsWith(".gradle") || fileName.endsWith(".gradle.kts")
 			val isXml: Boolean = fileName.endsWith(".xml")
 			if (!result.gradleSaved) {