Android: Add inspection & quickfix to convert findViewById to api 26

#KT-19940 Fixed Target Version 1.1.5

compiler/frontend/src/org/jetbrains/kotlin/psi/psiUtil/ktPsiUtil.kt

@@ -533,6 +533,15 @@ fun KtCallExpression.getOrCreateValueArgumentList(): KtValueArgumentList {
                     typeArgumentList ?: calleeExpression) as KtValueArgumentList
 }
 
+fun KtCallExpression.addTypeArgument(typeArgument: KtTypeProjection) {
+    if (typeArgumentList != null) {
+        typeArgumentList?.addArgument(typeArgument)
+    }
+    else {
+        addAfter(KtPsiFactory(this).createTypeArguments("<${typeArgument.text}>"), calleeExpression)
+    }
+}
+
 fun KtDeclaration.hasBody() = when (this) {
     is KtFunction -> hasBody()
     is KtProperty -> hasBody()

download_android_sdk.xml

@@ -34,7 +34,7 @@
         <mkdir dir="${android.sdk.dir}/build-tools"/>
 
         <download_android_platform android.versioncode="23_r01" android.sdk.version="23" android.full.version="6.0" />
-        <download_android_platform_new android.versioncode="25_r01" android.sdk.version="25" android.full.version="7.1.1" />
+        <download_android_platform_new android.versioncode="26_r02" android.sdk.version="26" android.full.version="8.0.0" />
 
         <download_support_repository android.repo.version="44" android.repo.last="25.2.0"/>
 

idea/idea-android/src/org/jetbrains/kotlin/android/inspection/TypeParameterFindViewByIdInspection.kt

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.android.inspection
+
+import com.intellij.codeInspection.*
+import com.intellij.openapi.project.Project
+import com.intellij.psi.PsiElementVisitor
+import org.jetbrains.android.facet.AndroidFacet
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.inspections.AbstractKotlinInspection
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.KtPsiUtil.isUnsafeCast
+import org.jetbrains.kotlin.psi.psiUtil.addTypeArgument
+import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+
+class TypeParameterFindViewByIdInspection : AbstractKotlinInspection(), CleanupLocalInspectionTool {
+    override fun buildVisitor(holder: ProblemsHolder, isOnTheFly: Boolean, session: LocalInspectionToolSession): PsiElementVisitor {
+        val compileSdk = AndroidFacet.getInstance(session.file)?.androidModuleInfo?.buildSdkVersion?.apiLevel
+        if (compileSdk == null || compileSdk < 26) {
+            return KtVisitorVoid()
+        }
+
+        return object : KtVisitorVoid() {
+            override fun visitCallExpression(expression: KtCallExpression) {
+                super.visitCallExpression(expression)
+                if (expression.calleeExpression?.text != "findViewById" || expression.typeArguments.isNotEmpty()) {
+                    return
+                }
+
+                val parentCast = (expression.parent as? KtBinaryExpressionWithTypeRHS)?.takeIf { isUnsafeCast(it) } ?: return
+                val typeText = parentCast.right?.getTypeTextWithoutQuestionMark() ?: return
+                val callableDescriptor = expression.getResolvedCall(expression.analyze())?.resultingDescriptor ?: return
+                if (callableDescriptor.name.asString() != "findViewById" || callableDescriptor.typeParameters.size != 1) {
+                    return
+                }
+
+                holder.registerProblem(
+                        parentCast,
+                        "Can be converted to findViewById<$typeText>(...)",
+                        ConvertCastToFindViewByIdWithTypeParameter())
+            }
+        }
+    }
+
+    class ConvertCastToFindViewByIdWithTypeParameter : LocalQuickFix {
+        override fun getFamilyName(): String = "Convert cast to findViewById with type parameter"
+
+        override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
+            val cast = descriptor.psiElement as? KtBinaryExpressionWithTypeRHS ?: return
+            val typeText = cast.right?.getTypeTextWithoutQuestionMark() ?: return
+            val call = cast.left as? KtCallExpression ?: return
+
+            val newCall = call.copy() as KtCallExpression
+            val typeArgument = KtPsiFactory(call).createTypeArgument(typeText)
+            newCall.addTypeArgument(typeArgument)
+
+            cast.replace(newCall)
+        }
+    }
+
+    companion object {
+        fun KtTypeReference.getTypeTextWithoutQuestionMark(): String? =
+                (typeElement as? KtNullableType)?.innerType?.text ?: typeElement?.text
+    }
+}

idea/idea-android/tests/org/jetbrains/kotlin/android/TestUtils.java

@@ -34,6 +34,6 @@ public class TestUtils {
 
     @NonNull
     public static String getLatestAndroidPlatform() {
-        return "android-25";
+        return "android-26";
     }
 }

idea/idea-android/tests/org/jetbrains/kotlin/android/lint/AbstractKotlinLintTest.kt

@@ -16,6 +16,7 @@
 
 package org.jetbrains.kotlin.android.lint
 
+import com.intellij.codeInspection.InspectionProfileEntry
 import com.intellij.testFramework.fixtures.impl.CodeInsightTestFixtureImpl
 import com.intellij.util.PathUtil
 import org.jetbrains.android.inspections.klint.AndroidLintInspectionBase
@@ -53,7 +54,7 @@ abstract class AbstractKotlinLintTest : KotlinAndroidTestCase() {
 
         myFixture.enableInspections(*inspectionClassNames.map { className ->
             val inspectionClass = Class.forName(className)
-            inspectionClass.newInstance() as AndroidLintInspectionBase
+            inspectionClass.newInstance() as InspectionProfileEntry
         }.toTypedArray())
 
         val additionalResourcesDir = File(ktFile.parentFile, getTestName(true))
@@ -76,6 +77,6 @@ abstract class AbstractKotlinLintTest : KotlinAndroidTestCase() {
             myFixture.copyFileToProject("${PathUtil.getParentPath(path)}/$dependencyFile", "src/$dependencyTargetPath")
         }
 
-        myFixture.checkHighlighting(true, false, false)
+        myFixture.checkHighlighting(true, false, true)
     }
 }

idea/idea-android/tests/org/jetbrains/kotlin/android/lint/KotlinLintTestGenerated.java

@@ -66,6 +66,12 @@ public class KotlinLintTestGenerated extends AbstractKotlinLintTest {
         doTest(fileName);
     }
 
+    @TestMetadata("findViewById.kt")
+    public void testFindViewById() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/android/lint/findViewById.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("javaPerformance.kt")
     public void testJavaPerformance() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/android/lint/javaPerformance.kt");

idea/idea-android/tests/org/jetbrains/kotlin/android/quickfix/AndroidLintQuickfixTestGenerated.java

@@ -36,6 +36,27 @@ public class AndroidLintQuickfixTestGenerated extends AbstractAndroidLintQuickfi
         KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/android/lintQuickfix"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
     }
 
+    @TestMetadata("idea/testData/android/lintQuickfix/findViewById")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class FindViewById extends AbstractAndroidLintQuickfixTest {
+        public void testAllFilesPresentInFindViewById() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/android/lintQuickfix/findViewById"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("nullableType.kt")
+        public void testNullableType() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/android/lintQuickfix/findViewById/nullableType.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("simple.kt")
+        public void testSimple() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/android/lintQuickfix/findViewById/simple.kt");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("idea/testData/android/lintQuickfix/parcelable")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

idea/resources/inspectionDescriptions/TypeParameterFindViewById.html

@@ -0,0 +1,5 @@
+<html>
+<body>
+Reports <code>findViewById</code> calls with type cast which can be converted to <code>findViewById</code> with type parameter from Android 8.0 (API level 26)
+</body>
+</html>

idea/src/META-INF/android.xml

@@ -12,10 +12,18 @@
 
         <localInspection implementationClass="org.jetbrains.kotlin.android.inspection.IllegalIdentifierInspection"
                          displayName="Illegal Android Identifier"
-                         groupName="Kotlin"
+                         groupName="Kotlin Android"
                          enabledByDefault="true"
                          level="ERROR"/>
 
+        <localInspection implementationClass="org.jetbrains.kotlin.android.inspection.TypeParameterFindViewByIdInspection"
+                         displayName="Cast can be converted to findViewById with type parameter"
+                         groupName="Kotlin Android"
+                         enabledByDefault="true"
+                         cleanupTool="true"
+                         level="WEAK WARNING"
+                         language="kotlin" />
+
         <editorNotificationProvider implementation="org.jetbrains.kotlin.android.actions.KotlinNewActivityNotification"/>
 
         <codeInsight.lineMarkerProvider language="kotlin" implementationClass="org.jetbrains.kotlin.android.KotlinAndroidLineMarkerProvider"/>

idea/testData/android/lint/findViewById.kt

@@ -0,0 +1,49 @@
+// INSPECTION_CLASS: org.jetbrains.kotlin.android.inspection.TypeParameterFindViewByIdInspection
+
+import android.app.Activity
+import android.os.Bundle
+import android.widget.Button
+import android.widget.TextView
+
+@Suppress(
+        "TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER",
+        "UNUSED_VARIABLE"
+)
+class OtherActivity : Activity() {
+
+    override fun onCreate(savedInstanceState: Bundle) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_other)
+
+        <weak_warning descr="Can be converted to findViewById<TextView>(...)">findViewById(R.id.tvHello) as TextView</weak_warning>
+        val tvHello = <weak_warning descr="Can be converted to findViewById<TextView>(...)">findViewById(R.id.tvHello) as TextView</weak_warning>
+        val btnGo = <weak_warning descr="Can be converted to findViewById<Button>(...)">findViewById(R.id.btnGo) as Button?</weak_warning>
+
+        // should be ok, already has type parameter
+        val tvHello2 = findViewById<TextView>(R.id.tvHello) as TextView
+
+        // ok, we can't convert safe cast because semantic will be changed
+        val tvHello3 = findViewById(R.id.tvHello) as? TextView
+
+        // ok, no cast
+        foo(findViewById(R.id.tvHello))
+
+        // ok, no cast
+        findViewById(R.id.tvHello) is TextView
+    }
+
+    fun foo(view: TextView) {
+        view.text = "foo"
+    }
+}
+
+class R {
+    object layout {
+        val activity_other = 100500
+    }
+
+    object id {
+        val tvHello = 0
+        val btnGo = 1
+    }
+}

idea/testData/android/lint/viewHolder.kt

@@ -29,7 +29,7 @@ abstract class ViewHolderTest : BaseAdapter() {
             // Should use View Holder pattern here
             convertView = mInflater.<warning descr="Unconditional layout inflation from view adapter: Should use View Holder pattern (use recycled view passed into this method as the second parameter) for smoother scrolling">inflate(R.layout.your_layout, null)</warning>
 
-            val text = convertView.findViewById(R.id.text) as TextView
+            val text: TextView = convertView.findViewById(R.id.text)
             text.text = "Position " + position
 
             return convertView
@@ -46,7 +46,7 @@ abstract class ViewHolderTest : BaseAdapter() {
                 convertView = mInflater.inflate(R.layout.your_layout, null)
             }
 
-            val text = convertView!!.findViewById(R.id.text) as TextView
+            val text: TextView = convertView!!.findViewById(R.id.text)
             text.text = "Position " + position
 
             return convertView
@@ -65,7 +65,7 @@ abstract class ViewHolderTest : BaseAdapter() {
                 convertView = mInflater.inflate(R.layout.your_layout, null)
             }
 
-            val text = convertView!!.findViewById(R.id.text) as TextView
+            val text: TextView = convertView!!.findViewById(R.id.text)
             text.text = "Position " + position
 
             return convertView
@@ -80,7 +80,7 @@ abstract class ViewHolderTest : BaseAdapter() {
             // Already using View Holder pattern
             convertView = if (convertView == null) mInflater.inflate(R.layout.your_layout, null) else convertView
 
-            val text = convertView!!.findViewById(R.id.text) as TextView
+            val text: TextView = convertView!!.findViewById(R.id.text)
             text.text = "Position " + position
 
             return convertView
@@ -99,16 +99,16 @@ abstract class ViewHolderTest : BaseAdapter() {
             var v: View? = convertView
             if (v == null) v = mLayoutInflator!!.inflate(R.layout.your_layout, null)
 
-            val listItemHolder = v!!.findViewById(R.id.laptimes_list_item_holder) as LinearLayout
+            val listItemHolder: LinearLayout = v!!.findViewById(R.id.laptimes_list_item_holder)
             listItemHolder.removeAllViews()
 
             for (i in 1..5) {
-                val lapItemView = mLayoutInflator!!.inflate(R.layout.laptime_item, null)
+                val lapItemView: View  = mLayoutInflator!!.inflate(R.layout.laptime_item, null)
                 if (i == 0) {
-                    val t = lapItemView.findViewById(R.id.laptime_text) as TextView
+                    val t: TextView = lapItemView.findViewById(R.id.laptime_text)
                 }
 
-                val t2 = lapItemView.findViewById(R.id.laptime_text2) as TextView
+                val t2: TextView = lapItemView.findViewById(R.id.laptime_text2)
                 if (i < mLapTimes.size - 1 && mLapTimes.size > 1) {
                     var laptime = mLapTimes[i] - mLapTimes[i + 1]
                     if (laptime < 0) laptime = mLapTimes[i]

idea/testData/android/lintQuickfix/findViewById/nullableType.kt

@@ -0,0 +1,28 @@
+// INTENTION_TEXT: Convert cast to findViewById with type parameter
+// INSPECTION_CLASS: org.jetbrains.kotlin.android.inspection.TypeParameterFindViewByIdInspection
+
+import android.app.Activity
+import android.os.Bundle
+import android.widget.Button
+import android.widget.TextView
+
+
+class OtherActivity : Activity() {
+
+    override fun onCreate(savedInstanceState: Bundle) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_other)
+
+        val tvHello = <caret>findViewById(R.id.tvHello) as TextView?
+    }
+}
+
+class R {
+    object layout {
+        val activity_other = 100500
+    }
+
+    object id {
+        val tvHello = 0
+    }
+}

idea/testData/android/lintQuickfix/findViewById/nullableType.kt.expected

@@ -0,0 +1,28 @@
+// INTENTION_TEXT: Convert cast to findViewById with type parameter
+// INSPECTION_CLASS: org.jetbrains.kotlin.android.inspection.TypeParameterFindViewByIdInspection
+
+import android.app.Activity
+import android.os.Bundle
+import android.widget.Button
+import android.widget.TextView
+
+
+class OtherActivity : Activity() {
+
+    override fun onCreate(savedInstanceState: Bundle) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_other)
+
+        val tvHello = findViewById<TextView>(R.id.tvHello)
+    }
+}
+
+class R {
+    object layout {
+        val activity_other = 100500
+    }
+
+    object id {
+        val tvHello = 0
+    }
+}

idea/testData/android/lintQuickfix/findViewById/simple.kt

@@ -0,0 +1,28 @@
+// INTENTION_TEXT: Convert cast to findViewById with type parameter
+// INSPECTION_CLASS: org.jetbrains.kotlin.android.inspection.TypeParameterFindViewByIdInspection
+
+import android.app.Activity
+import android.os.Bundle
+import android.widget.Button
+import android.widget.TextView
+
+
+class OtherActivity : Activity() {
+
+    override fun onCreate(savedInstanceState: Bundle) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_other)
+
+        val tvHello = <caret>findViewById(R.id.tvHello) as TextView
+    }
+}
+
+class R {
+    object layout {
+        val activity_other = 100500
+    }
+
+    object id {
+        val tvHello = 0
+    }
+}

idea/testData/android/lintQuickfix/findViewById/simple.kt.expected

@@ -0,0 +1,28 @@
+// INTENTION_TEXT: Convert cast to findViewById with type parameter
+// INSPECTION_CLASS: org.jetbrains.kotlin.android.inspection.TypeParameterFindViewByIdInspection
+
+import android.app.Activity
+import android.os.Bundle
+import android.widget.Button
+import android.widget.TextView
+
+
+class OtherActivity : Activity() {
+
+    override fun onCreate(savedInstanceState: Bundle) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_other)
+
+        val tvHello = findViewById<TextView>(R.id.tvHello)
+    }
+}
+
+class R {
+    object layout {
+        val activity_other = 100500
+    }
+
+    object id {
+        val tvHello = 0
+    }
+}