fix: save state when rotating screen (#111)

* Fixed Text File Editor losing unsaved changes when rotating screen

* style: replace state variable with constant

---------

Co-authored-by: Naveen Singh <[email protected]>
Co-authored-by: Naveen Singh <[email protected]>

Author: Burgerpower01

app/src/main/kotlin/org/fossify/filemanager/activities/ReadTextActivity.kt

@@ -32,6 +32,7 @@ class ReadTextActivity : SimpleActivity() {
     companion object {
         private const val SELECT_SAVE_FILE_INTENT = 1
         private const val SELECT_SAVE_FILE_AND_EXIT_INTENT = 2
+        private const val KEY_UNSAVED_TEXT = "KEY_UNSAVED_TEXT"
     }
 
     private val binding by viewBinding(ActivityReadTextBinding::inflate)
@@ -85,7 +86,7 @@ class ReadTextActivity : SimpleActivity() {
 
         binding.readTextView.onGlobalLayout {
             ensureBackgroundThread {
-                checkIntent(uri)
+                checkIntent(uri, savedInstanceState)
             }
         }
 
@@ -97,6 +98,13 @@ class ReadTextActivity : SimpleActivity() {
         setupToolbar(binding.readTextToolbar, NavigationIcon.Arrow)
     }
 
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        if (originalText != binding.readTextView.text.toString()) {
+            outState.putString(KEY_UNSAVED_TEXT, binding.readTextView.text.toString())
+        }
+    }
+
     override fun onActivityResult(requestCode: Int, resultCode: Int, resultData: Intent?) {
         super.onActivityResult(requestCode, resultCode, resultData)
         if (requestCode == SELECT_SAVE_FILE_INTENT && resultCode == Activity.RESULT_OK && resultData != null && resultData.data != null) {
@@ -241,7 +249,7 @@ class ReadTextActivity : SimpleActivity() {
         }
     }
 
-    private fun checkIntent(uri: Uri) {
+    private fun checkIntent(uri: Uri, savedInstanceState: Bundle?) {
         originalText = if (uri.scheme == "file") {
             filePath = uri.path!!
             val file = File(filePath)
@@ -270,7 +278,13 @@ class ReadTextActivity : SimpleActivity() {
         }
 
         runOnUiThread {
-            binding.readTextView.setText(originalText)
+            var textToSet = originalText
+
+            if (savedInstanceState != null) {
+                textToSet = savedInstanceState.getString(KEY_UNSAVED_TEXT, originalText)
+            }
+
+            binding.readTextView.setText(textToSet)
             if (originalText.isNotEmpty()) {
                 hideKeyboard()
             } else {