fix: parse OpenedFilesCache manually to avoid ClassCastException in release builds (fixes #1102)

Author: itsaky

app/proguard-rules.pro

@@ -4,6 +4,10 @@
 -dontnote **
 -dontobfuscate
 
+-keepattributes Signature
+-keepattributes Exceptions
+-keepattributes *Annotation*
+
 -keep class javax.** { *; }
 -keep class jdkx.** { *; }
 
@@ -35,7 +39,6 @@
 }
 
 # EventBus
--keepattributes *Annotation*
 -keepclassmembers class ** {
     @org.greenrobot.eventbus.Subscribe <methods>;
 }
@@ -91,19 +94,29 @@
 # Retrofit 2
 -dontwarn retrofit2.**
 -keep class retrofit2.** { *; }
--keepattributes Signature
--keepattributes Exceptions
 
 -keepclasseswithmembers class * {
     @retrofit2.http.* <methods>;
 }
 
 # OkHttp3
--keepattributes Signature
--keepattributes *Annotation*
 -keep class okhttp3.** { *; }
 -keep interface okhttp3.** { *; }
 -dontwarn okhttp3.**
 
 # Stat uploader
--keep class com.itsaky.androidide.stats.** { *; }
+-keep class com.itsaky.androidide.stats.** { *; }
+
+# Gson
+-keep class * extends com.google.gson.TypeAdapter
+-keep class * implements com.google.gson.TypeAdapterFactory
+-keep class * implements com.google.gson.JsonSerializer
+-keep class * implements com.google.gson.JsonDeserializer
+
+-keepclassmembers,allowobfuscation class * {
+  @com.google.gson.annotations.SerializedName <fields>;
+}
+
+## Retain generic signatures of TypeToken and its subclasses with R8 version 3.0 and higher.
+-keep,allowobfuscation,allowshrinking class com.google.gson.reflect.TypeToken
+-keep,allowobfuscation,allowshrinking class * extends com.google.gson.reflect.TypeToken

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

@@ -163,15 +163,13 @@ open class EditorHandlerActivity : ProjectHandlerActivity(), IEditorHandler {
 
     try {
       if (viewModel.openedFilesCache != null) {
-        viewModel.openedFilesCache?.apply {
-          this.allFiles.forEach { openFile(File(it.filePath), it.selection) }
-          openFile(File(selectedFile))
+        viewModel.openedFilesCache?.let { cache ->
+          onReadOpenedFilesCache(cache)
         }
       } else {
-        viewModel.readOpenedFiles {
-          it ?: return@readOpenedFiles
-          it.allFiles.forEach { file -> openFile(File(file.filePath), file.selection) }
-          openFile(File(it.selectedFile))
+        viewModel.readOpenedFiles { cache ->
+          cache ?: return@readOpenedFiles
+          onReadOpenedFilesCache(cache)
         }
       }
       viewModel.openedFilesCache = null
@@ -180,6 +178,13 @@ open class EditorHandlerActivity : ProjectHandlerActivity(), IEditorHandler {
     }
   }
 
+  private fun onReadOpenedFilesCache(cache: OpenedFilesCache) {
+    cache.allFiles.forEach { file ->
+      openFile(File(file.filePath), file.selection)
+    }
+    openFile(File(cache.selectedFile))
+  }
+
   override fun onPrepareOptionsMenu(menu: Menu): Boolean {
     ensureToolbarMenu(menu)
     return true

app/src/main/java/com/itsaky/androidide/models/OpenedFile.kt

@@ -17,14 +17,48 @@
 
 package com.itsaky.androidide.models
 
+import com.google.gson.Gson
 import com.google.gson.annotations.SerializedName
+import com.google.gson.stream.JsonReader
+import com.itsaky.androidide.utils.ILogger
 
 /**
  * A file that is opened in editor.
  *
  * @author Akash Yadav
  */
 data class OpenedFile(
-  @SerializedName("file") val filePath: String,
-  @SerializedName("selection") var selection: Range
-)
+  @SerializedName(KEY_FILE) val filePath: String,
+  @SerializedName(KEY_SELECTION) var selection: Range
+) {
+
+  companion object {
+
+    private const val KEY_FILE = "file"
+    private const val KEY_SELECTION = "selection"
+    private val log = ILogger.newInstance("OpenedFile")
+
+    fun readFrom(reader: JsonReader): OpenedFile? {
+      return try {
+//        reader.beginObject()
+//        var path = ""
+//        var selection = Range.NONE
+//        while(reader.hasNext()) {
+//          val name = reader.nextName()
+//          if (name == KEY_FILE) {
+//            path = reader.nextString()
+//          } else if (name == KEY_SELECTION) {
+//            selection = Gson().fromJson(reader, Range::class.java)
+//          }
+//        }
+//        reader.endObject()
+//
+//        OpenedFile(path, selection)
+        Gson().fromJson(reader, OpenedFile::class.java)
+      } catch (err: Exception) {
+        log.error("Failed to read opened file", err)
+        null
+      }
+    }
+  }
+}

app/src/main/java/com/itsaky/androidide/models/OpenedFilesCache.kt

@@ -17,7 +17,56 @@
 
 package com.itsaky.androidide.models
 
+import com.google.gson.Gson
+import com.google.gson.annotations.SerializedName
+import com.google.gson.reflect.TypeToken
+import com.google.gson.stream.JsonReader
+import com.itsaky.androidide.utils.ILogger
+import java.io.Reader
+
 /**
  * @author Akash Yadav
  */
-data class OpenedFilesCache(val selectedFile: String, val allFiles: List<OpenedFile>)
+data class OpenedFilesCache(@SerializedName(KEY_SELECTED_FILE) val selectedFile: String,
+  @SerializedName(KEY_ALL_FILES) val allFiles: List<OpenedFile>) {
+
+  companion object {
+
+    private const val KEY_SELECTED_FILE = "selectedFile"
+    private const val KEY_ALL_FILES = "allFiles"
+    private val log = ILogger.newInstance("OpenedFilesCache")
+
+    @JvmStatic
+    fun parse(contentReader: Reader): OpenedFilesCache? {
+      return try {
+        JsonReader(contentReader).use { reader ->
+          if (!reader.hasNext()) {
+            return@use null
+          }
+
+          reader.beginObject()
+          var selectedFile = ""
+          var allFiles = emptyList<OpenedFile>()
+          while (reader.hasNext()) {
+            val name = reader.nextName()
+
+            if (name == KEY_SELECTED_FILE) {
+              selectedFile = reader.nextString()
+            } else if (name == KEY_ALL_FILES) {
+              allFiles = Gson().fromJson(reader, object : TypeToken<List<OpenedFile>>() {})
+            }
+          }
+          reader.endObject()
+
+          return@use OpenedFilesCache(selectedFile, allFiles)
+        }
+      } catch (err: Exception) {
+        log.error("Failed to parse opened files cache", err)
+        null
+      }
+    }
+
+    private fun readOpenedFiles(reader: JsonReader, allFiles: MutableList<OpenedFile>) {
+    }
+  }
+}

app/src/main/java/com/itsaky/androidide/viewmodel/EditorViewModel.kt

@@ -25,6 +25,7 @@ import androidx.lifecycle.ViewModel
 import com.blankj.utilcode.util.FileUtils
 import com.google.gson.Gson
 import com.google.gson.GsonBuilder
+import com.google.gson.reflect.TypeToken
 import com.itsaky.androidide.models.OpenedFilesCache
 import com.itsaky.androidide.projects.ProjectManager
 import com.itsaky.androidide.tasks.executeAsync
@@ -199,11 +200,13 @@ class EditorViewModel : ViewModel() {
 
   fun readOpenedFiles(result: (OpenedFilesCache?) -> Unit) {
     executeAsync({
-      val file = getOpenedFilesCache()
+      val file = getOpenedFilesCache(false)
       if (file.length() == 0L) {
         return@executeAsync null
       }
-      return@executeAsync Gson().fromJson(file.readText(), OpenedFilesCache::class.java)
+      return@executeAsync file.reader().buffered().use { reader ->
+        OpenedFilesCache.parse(reader)
+      }
     }) {
       result(it)
     }
@@ -224,17 +227,17 @@ class EditorViewModel : ViewModel() {
     }
   }
 
-  private fun getOpenedFilesCache(): File {
+  private fun getOpenedFilesCache(forWrite: Boolean = false): File {
     var file = Environment.getProjectCacheDir(ProjectManager.projectPath)
     file = File(file, "editor/openedFiles.json")
-    if (file.exists()) {
+    if (file.exists() && forWrite) {
       FileUtils.rename(file, "${file.name}.bak")
     }
 
     if (file.parentFile?.exists() == false) {
       file.parentFile?.mkdirs()
     }
-  
+
     file.createNewFile()
 
     return file

shared/build.gradle.kts

@@ -24,6 +24,7 @@ plugins {
 dependencies {
     implementation(libs.androidx.annotation)
     implementation(libs.google.guava)
+    implementation(libs.google.gson)
     implementation(projects.logger)
 
     testImplementation(libs.tests.google.truth)

shared/src/main/java/com/itsaky/androidide/models/Locations.kt

@@ -17,12 +17,16 @@
 
 package com.itsaky.androidide.models
 
+import com.google.gson.annotations.SerializedName
 import java.nio.file.Path
 
 data class Location(var file: Path, var range: Range)
 
-data class Position @JvmOverloads constructor(var line: Int, var column: Int, var index: Int = -1) :
-  Comparable<Position> {
+data class Position @JvmOverloads constructor(
+  @SerializedName("line") var line: Int,
+  @SerializedName("column") var column: Int,
+  @SerializedName("index") var index: Int = -1
+) : Comparable<Position> {
 
   fun requireIndex(): Int {
     if (index == -1) {
@@ -43,7 +47,9 @@ data class Position @JvmOverloads constructor(var line: Int, var column: Int, va
   }
 
   companion object {
-    @JvmField val NONE = Position(-1, -1)
+
+    @JvmField
+    val NONE = Position(-1, -1)
   }
 
   override fun compareTo(other: Position): Int {
@@ -85,21 +91,26 @@ data class Position @JvmOverloads constructor(var line: Int, var column: Int, va
 
 open class Range
 @JvmOverloads
-constructor(var start: Position = Position(0, 0), var end: Position = Position(0, 0)) :
-  Comparable<Range> {
-  
-  constructor(src: Range) : this(Position(src.start.line, src.start.column), Position(src.end.line, src.end.column))
+constructor(
+  @SerializedName("start") var start: Position = Position(0, 0),
+  @SerializedName("end") var end: Position = Position(0, 0)
+) : Comparable<Range> {
+
+  constructor(src: Range) : this(Position(src.start.line, src.start.column),
+    Position(src.end.line, src.end.column))
 
   companion object {
-    @JvmField val NONE = Range(Position.NONE, Position.NONE)
+
+    @JvmField
+    val NONE = Range(Position.NONE, Position.NONE)
 
     @JvmStatic
-    fun pointRange(line: Int, column: Int) : Range {
+    fun pointRange(line: Int, column: Int): Range {
       return pointRange(Position(line, column))
     }
 
     @JvmStatic
-    fun pointRange(position: Position) : Range {
+    fun pointRange(position: Position): Range {
       return Range(position, position)
     }
   }