Move createSessionForLookupElement() to ImplementationViewSessionFactory; clarify code (IDEA-CR-41751)

platform/lang-impl/src/com/intellij/codeInsight/hint/ImplementationViewSession.kt

@@ -1,6 +1,8 @@
 // Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.codeInsight.hint
 
+import com.intellij.codeInsight.documentation.DocumentationManager
+import com.intellij.codeInsight.hint.PsiImplementationViewSession.getSelfAndImplementations
 import com.intellij.openapi.actionSystem.DataContext
 import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.extensions.ExtensionPointName
@@ -8,10 +10,17 @@ import com.intellij.openapi.progress.ProgressIndicator
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
+import com.intellij.psi.presentation.java.SymbolPresentationUtil
 import com.intellij.util.Processor
 
 interface ImplementationViewSession {
+  val factory: ImplementationViewSessionFactory
   val project: Project
+
+  /**
+   * The list of implementations which could be found synchronously. Additional implementations can be obtained by calling
+   * [searchImplementationsInBackground].
+   */
   val implementationElements: List<ImplementationViewElement>
   val file: PsiFile?
 
@@ -19,8 +28,6 @@ interface ImplementationViewSession {
   val text: String?
   val editor: Editor?
 
-  fun createSessionForLookupElement(lookupItemObject: Any?, isSearchDeep: Boolean): ImplementationViewSession?
-
   fun searchImplementationsInBackground(indicator: ProgressIndicator,
                                         isSearchDeep: Boolean,
                                         includeSelf: Boolean,
@@ -31,6 +38,7 @@ interface ImplementationViewSession {
 
 interface ImplementationViewSessionFactory {
   fun createSession(dataContext: DataContext, project: Project, invokedByShortcut: Boolean): ImplementationViewSession?
+  fun createSessionForLookupElement(project: Project, editor: Editor?, file: PsiFile?, lookupItemObject: Any?, isSearchDeep: Boolean): ImplementationViewSession?
 
   companion object {
     @JvmField val EP_NAME = ExtensionPointName.create<ImplementationViewSessionFactory>("com.intellij.implementationViewSessionFactory")
@@ -41,4 +49,20 @@ class PsiImplementationSessionViewFactory : ImplementationViewSessionFactory {
   override fun createSession(dataContext: DataContext, project: Project, invokedByShortcut: Boolean): ImplementationViewSession? {
     return PsiImplementationViewSession.create(dataContext, project, invokedByShortcut)
   }
+
+  override fun createSessionForLookupElement(project: Project, editor: Editor?, file: PsiFile?, lookupItemObject: Any?, isSearchDeep: Boolean): ImplementationViewSession? {
+    val element = lookupItemObject as? PsiElement ?: DocumentationManager.getInstance(project).getElementFromLookup(editor, file)
+    var impls = arrayOf<PsiElement>()
+    var text = ""
+    if (element != null) {
+      // if (element instanceof PsiPackage) return;
+      val containingFile = element.containingFile
+      if (containingFile == null || !containingFile.viewProvider.isPhysical) return null
+
+      impls = getSelfAndImplementations(editor, element, PsiImplementationViewSession.createImplementationsSearcher(isSearchDeep))
+      text = SymbolPresentationUtil.getSymbolPresentableText(element)
+    }
+
+    return PsiImplementationViewSession(project, element, impls, text, editor, file)
+  }
 }

platform/lang-impl/src/com/intellij/codeInsight/hint/PsiImplementationViewSession.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.codeInsight.hint;
 
 import com.intellij.codeInsight.TargetElementUtil;
@@ -52,6 +52,12 @@ public class PsiImplementationViewSession implements ImplementationViewSession {
     myFile = file;
   }
 
+  @NotNull
+  @Override
+  public ImplementationViewSessionFactory getFactory() {
+    return ImplementationViewSessionFactory.EP_NAME.findExtensionOrFail(PsiImplementationSessionViewFactory.class);
+  }
+
   @NotNull
   public Project getProject() {
     return myProject;
@@ -83,25 +89,6 @@ public class PsiImplementationViewSession implements ImplementationViewSession {
     return myFile;
   }
 
-  @Override
-  public PsiImplementationViewSession createSessionForLookupElement(Object lookupItemObject, boolean isSearchDeep) {
-    final PsiElement element = lookupItemObject instanceof PsiElement
-                               ? (PsiElement)lookupItemObject
-                               : DocumentationManager.getInstance(myProject).getElementFromLookup(myEditor, myFile);
-    PsiElement[] impls = {};
-    String text = "";
-    if (element != null) {
-      // if (element instanceof PsiPackage) return;
-      PsiFile containingFile = element.getContainingFile();
-      if (containingFile == null || !containingFile.getViewProvider().isPhysical()) return null;
-
-      impls = getSelfAndImplementations(myEditor, element, PsiImplementationViewSession.createImplementationsSearcher(isSearchDeep));
-      text = SymbolPresentationUtil.getSymbolPresentableText(element);
-    }
-
-    return new PsiImplementationViewSession(myProject, element, impls, text, myEditor, myFile);
-  }
-
   @Override
   public boolean elementRequiresIncludeSelf() {
     return !(myElement instanceof PomTargetPsiElement);

platform/lang-impl/src/com/intellij/codeInsight/hint/actions/ShowImplementationsAction.java

@@ -1,4 +1,4 @@
-// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.codeInsight.hint.actions;
 
 import com.intellij.codeInsight.CodeInsightBundle;
@@ -87,7 +87,8 @@ public class ShowImplementationsAction extends AnAction implements PopupAction {
   }
 
   private void updateElementImplementations(final Object lookupItemObject, ImplementationViewSession session) {
-    ImplementationViewSession newSession = session.createSessionForLookupElement(lookupItemObject, isSearchDeep());
+    ImplementationViewSession newSession = session.getFactory().createSessionForLookupElement(session.getProject(),
+                                                                                              session.getEditor(), session.getFile(), lookupItemObject, isSearchDeep());
     if (newSession != null) {
       showImplementations(newSession, false, false);
     }