Optimize exception message when depends on support library version is older than 25.1.0.

Author: bennyhuo

MainScope/src/main/java/com/bennyhuo/kotlin/coroutines/android/mainscope/MainScope.kt

@@ -18,7 +18,7 @@ interface MainScope: CoroutineScope{
 
         val isFragmentSupported by lazy {
             try {
-                Class.forName("android.support.v4.app.Fragment")
+                Class.forName("android.support.v4.app.FragmentManager\$FragmentLifecycleCallbacks")
                 Logcat.debug("Fragment enabled.")
                 true
             }catch (e: ClassNotFoundException){

MainScope/src/main/java/com/bennyhuo/kotlin/coroutines/android/mainscope/exception/Exceptions.kt

@@ -0,0 +1,6 @@
+package com.bennyhuo.kotlin.coroutines.android.mainscope.exception
+
+class UnsupportedTypeException(type: Class<*>, vararg supportedTypes: String)
+    : Exception("Unsupported type: $type. ${supportedTypes.joinToString()} ${if(supportedTypes.size == 1) "is" else "are" } needed.")
+
+class UnsupportedVersionException(library: String, version: String): Exception("Unsupported version: $version of $library")

MainScope/src/main/java/com/bennyhuo/kotlin/coroutines/android/mainscope/scope/MainScoped.kt

@@ -6,6 +6,8 @@ import android.support.v4.app.Fragment
 import com.bennyhuo.kotlin.coroutines.android.mainscope.EmptyScope
 import com.bennyhuo.kotlin.coroutines.android.mainscope.MainScope
 import com.bennyhuo.kotlin.coroutines.android.mainscope.MainScopeImpl
+import com.bennyhuo.kotlin.coroutines.android.mainscope.exception.UnsupportedTypeException
+import com.bennyhuo.kotlin.coroutines.android.mainscope.exception.UnsupportedVersionException
 import com.bennyhuo.kotlin.coroutines.android.mainscope.utils.Logcat
 import kotlinx.coroutines.cancel
 import java.util.*
@@ -44,7 +46,17 @@ private fun MainScoped.isDestroyed(): Boolean {
             this.activity?.isFinishing?: true || this.isRemoving ||this.view == null
         }
         else ->{
-            throw IllegalAccessException("An Activity or android.support.v4.app.Fragment is needed!")
+            val fragmentClass = try {
+                Class.forName("android.support.v4.app.Fragment")
+            } catch (e: Exception) {
+                null
+            }
+            fragmentClass?.let {
+                if(it.isAssignableFrom(this.javaClass)){
+                    throw UnsupportedVersionException("com.android.support:support-fragment", "<25.1.0")
+                }
+            }
+            throw UnsupportedTypeException(this.javaClass, "android.app.Activity", "android.support.v4.app.Fragment")
         }
     }
 }

README.md

@@ -118,6 +118,8 @@ Most of the listeners borrowed from [Anko](https://github.com/kotlin/anko) are e
 
 Since `android.app.Fragment` is deprecated, we choose to support `android.support.v4.app.Fragment` only. If you include the library into the classpath, Fragment support will be automatically enabled for subtypes of `FragmentActivity`. Otherwise if you never use Fragment, don't worry, nothing will happen.
 
+ `FragmentLifecycleCallbacks` was added from v25.1.0 so older versions will not be supported.
+
 ## Issue
 
 Please feel free to issue and pull request.

app-fragment/build.gradle

@@ -22,13 +22,15 @@ android {
     }
 }
 
+def android_support_version_sample = "25.1.0"
+
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
     implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     implementation 'com.android.support.constraint:constraint-layout:1.1.3'
-    implementation "com.android.support:recyclerview-v7:$android_support_version"
-    implementation "com.android.support:design:$android_support_version"
-    implementation "com.android.support:appcompat-v7:$android_support_version"
+    implementation "com.android.support:recyclerview-v7:$android_support_version_sample"
+    implementation "com.android.support:design:$android_support_version_sample"
+    implementation "com.android.support:appcompat-v7:$android_support_version_sample"
 
     testImplementation 'junit:junit:4.12'
     androidTestImplementation 'com.android.support.test:runner:1.0.2'

app-fragment/src/main/java/com/bennyhuo/kotlin/coroutines/android/sample/MainActivity.kt

@@ -13,7 +13,7 @@ class MainActivity : AppCompatActivity(), BasicScoped {
 
         button.onClick {
             supportFragmentManager.beginTransaction()
-                    .setCustomAnimations(android.R.animator.fade_in,android.R.animator.fade_out)
+                    .setCustomAnimations(android.R.anim.fade_in,android.R.anim.fade_out)
                     .add(R.id.fragmentContainer, MainFragment())
                     .addToBackStack("Main").commit()
         }