Merge pull request #224 from caarmen/use-injected-io-dispatcher

caarmen · web-flow · commit 32e988a63fda · 2025-03-29T19:59:46.000+01:00
Provide an ioDispatcher via dagger. Use it to read the license text.
diff --git a/app/src/main/kotlin/ca/rmen/android/poetassistant/about/LicenseActivity.kt b/app/src/main/kotlin/ca/rmen/android/poetassistant/about/LicenseActivity.kt
@@ -22,17 +22,13 @@ package ca.rmen.android.poetassistant.about
 import android.content.Context
 import android.content.Intent
 import android.os.Bundle
-import android.util.Log
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
-import androidx.annotation.WorkerThread
+import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
+import androidx.compose.runtime.collectAsState
 import ca.rmen.android.poetassistant.Constants
-import ca.rmen.android.poetassistant.dagger.DaggerHelper
 import ca.rmen.android.poetassistant.theme.AppTheme
-import java.io.BufferedReader
-import java.io.IOException
-import java.io.InputStreamReader
 
 class LicenseActivity : AppCompatActivity() {
     companion object {
@@ -52,38 +48,20 @@ class LicenseActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
+        val licenseViewModel: LicenseViewModel by viewModels()
         val title = intent.getStringExtra(EXTRA_TITLE)!!
         val licenseFile = intent.getStringExtra(EXTRA_LICENSE_TEXT_ASSET_FILE)!!
-        val threading = DaggerHelper.getMainScreenComponent(this).getThreading()
-        threading.execute(
-            { readFile(licenseFile) },
-            {
-                setContent {
-                    AppTheme {
-                        LicenseScreen(
-                            title = title,
-                            licenseText = it,
-                            onBack = onBackPressedDispatcher::onBackPressed
-                        )
-                    }
-                }
-            })
-    }
-
-    @WorkerThread
-    private fun readFile(fileName: String): String {
-
-        try {
-            BufferedReader(InputStreamReader(assets.open(fileName))).use {
-                val builder = StringBuilder()
-                it.forEachLine { line ->
-                    builder.append(line).append('\n')
-                }
-                return builder.toString()
+        licenseViewModel.readLicenseText(licenseFile)
+        setContent {
+            val licenseText = licenseViewModel.licenseText.collectAsState()
+            AppTheme {
+                LicenseScreen(
+                    title = title,
+                    licenseText = licenseText.value,
+                    onBack = onBackPressedDispatcher::onBackPressed
+                )
             }
-        } catch (e: IOException) {
-            Log.e(TAG, "Couldn't read license file $fileName: ${e.message}", e)
-            return ""
         }
     }
+
 }
diff --git a/app/src/main/kotlin/ca/rmen/android/poetassistant/about/LicenseViewModel.kt b/app/src/main/kotlin/ca/rmen/android/poetassistant/about/LicenseViewModel.kt
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2025 - present Carmen Alvarez
+ *
+ * This file is part of Poet Assistant.
+ *
+ * Poet Assistant is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Poet Assistant is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Poet Assistant.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package ca.rmen.android.poetassistant.about
+
+import android.app.Application
+import android.util.Log
+import androidx.lifecycle.AndroidViewModel
+import androidx.lifecycle.viewModelScope
+import ca.rmen.android.poetassistant.Constants
+import ca.rmen.android.poetassistant.dagger.DaggerHelper
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import java.io.IOException
+import javax.inject.Inject
+
+class LicenseViewModel(private val application: Application) :
+    AndroidViewModel(application) {
+
+    companion object {
+        private val TAG = Constants.TAG + LicenseViewModel::class.java.simpleName
+    }
+
+    init {
+        DaggerHelper.getMainScreenComponent(application).inject(this)
+    }
+
+    @Inject
+    lateinit var ioDispatcher: CoroutineDispatcher
+
+    private val _licenseText = MutableStateFlow("")
+    val licenseText = _licenseText.asStateFlow()
+
+    fun readLicenseText(fileName: String) {
+        viewModelScope.launch(ioDispatcher) {
+            val contents = readFile(fileName)
+            _licenseText.value = contents
+        }
+    }
+
+    private fun readFile(fileName: String): String {
+        try {
+            return application.assets.open(fileName).bufferedReader().use { it.readText() }
+        } catch (e: IOException) {
+            Log.e(TAG, "Couldn't read license file $fileName: ${e.message}", e)
+            return ""
+        }
+    }
+}
diff --git a/app/src/main/kotlin/ca/rmen/android/poetassistant/dagger/AppComponent.kt b/app/src/main/kotlin/ca/rmen/android/poetassistant/dagger/AppComponent.kt
@@ -22,6 +22,7 @@ package ca.rmen.android.poetassistant.dagger
 import ca.rmen.android.poetassistant.Favorites
 import ca.rmen.android.poetassistant.PoemAudioExport
 import ca.rmen.android.poetassistant.Threading
+import ca.rmen.android.poetassistant.about.LicenseViewModel
 import ca.rmen.android.poetassistant.main.MainActivity
 import ca.rmen.android.poetassistant.main.dictionaries.ResultListAdapterFactory
 import ca.rmen.android.poetassistant.main.dictionaries.ResultListHeaderViewModel
@@ -48,6 +49,7 @@ import ca.rmen.android.poetassistant.wotd.WotdEntryViewModel
 import ca.rmen.android.poetassistant.wotd.WotdLiveData
 import dagger.Component
 import dagger.Subcomponent
+import kotlinx.coroutines.CoroutineDispatcher
 import javax.inject.Singleton
 
 @Singleton
@@ -64,6 +66,7 @@ interface AppComponent {
         fun getFavorites(): Favorites
         fun getSettingsPrefs(): SettingsPrefs
         fun getThreading(): Threading
+        fun getIODispatcher(): CoroutineDispatcher
         fun getResultListAdapterFactory() : ResultListAdapterFactory
     }
 
@@ -75,6 +78,7 @@ interface AppComponent {
         fun injectDict(resultListViewModel: ResultListViewModel<DictionaryEntry>)
         fun inject(rtEntry: RTEntryViewModel)
         fun inject(resultListHeaderViewModel: ResultListHeaderViewModel)
+        fun inject(licenseViewModel: LicenseViewModel)
         fun inject(readerViewModel: ReaderViewModel)
         fun inject(poemAudioExport: PoemAudioExport)
         fun inject(rhymerLiveData: RhymerLiveData)
diff --git a/app/src/main/kotlin/ca/rmen/android/poetassistant/dagger/ThreadingModule.kt b/app/src/main/kotlin/ca/rmen/android/poetassistant/dagger/ThreadingModule.kt
@@ -23,6 +23,7 @@ import ca.rmen.android.poetassistant.CoroutineThreading
 import ca.rmen.android.poetassistant.Threading
 import dagger.Module
 import dagger.Provides
+import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.Dispatchers
 import javax.inject.Singleton
 
@@ -31,4 +32,9 @@ class ThreadingModule {
     @Provides
     @Singleton
     fun providesThreading() : Threading = CoroutineThreading(Dispatchers.Default, Dispatchers.Main)
+
+
+    @Provides
+    @Singleton
+    fun providesIODispatcher(): CoroutineDispatcher = Dispatchers.IO
 }
diff --git a/app/src/sharedTest/kotlin/ca/rmen/android/poetassistant/dagger/TestThreadingModule.kt b/app/src/sharedTest/kotlin/ca/rmen/android/poetassistant/dagger/TestThreadingModule.kt
@@ -23,6 +23,9 @@ import ca.rmen.android.poetassistant.InstrumentationThreading
 import ca.rmen.android.poetassistant.Threading
 import dagger.Module
 import dagger.Provides
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
 import javax.inject.Singleton
 
 @Module
@@ -31,4 +34,9 @@ class TestThreadingModule {
     @Provides
     @Singleton
     fun providesThreading(): Threading = InstrumentationThreading()
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Provides
+    @Singleton
+    fun providesIODispatcher(): CoroutineDispatcher = UnconfinedTestDispatcher()
 }
diff --git a/app/src/test/kotlin/ca/rmen/android/poetassistant/dagger/JunitThreadingModule.kt b/app/src/test/kotlin/ca/rmen/android/poetassistant/dagger/JunitThreadingModule.kt
@@ -23,11 +23,19 @@ import ca.rmen.android.poetassistant.JunitThreading
 import ca.rmen.android.poetassistant.Threading
 import dagger.Module
 import dagger.Provides
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
 import javax.inject.Singleton
 
 @Module
 class JunitThreadingModule {
     @Provides
     @Singleton
     fun providesThreading() : Threading = JunitThreading()
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Provides
+    @Singleton
+    fun providesIODispatcher(): CoroutineDispatcher = UnconfinedTestDispatcher()
 }
