UX-1 new SearchEverywhere popup

* recent files

platform/lang-api/src/com/intellij/ide/actions/searcheverywhere/ContributorSearchResult.java

@@ -20,6 +20,10 @@ public class ContributorSearchResult<T> {
     this.hasMoreItems = hasMoreItems;
   }
 
+  public ContributorSearchResult(List<T> items) {
+    this(items, false);
+  }
+
   public List<T> getItems() {
     return items;
   }

platform/lang-impl/src/com/intellij/ide/actions/searcheverywhere/RecentFilesSEContributor.java

@@ -0,0 +1,65 @@
+// 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.
+package com.intellij.ide.actions.searcheverywhere;
+
+import com.google.common.collect.Lists;
+import com.intellij.openapi.fileEditor.FileEditorManager;
+import com.intellij.openapi.fileEditor.impl.EditorHistoryManager;
+import com.intellij.openapi.progress.ProgressIndicator;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.text.StringUtil;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.psi.PsiManager;
+import com.intellij.psi.codeStyle.MinusculeMatcher;
+import com.intellij.psi.codeStyle.NameUtil;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+public class RecentFilesSEContributor extends FileSearchEverywhereContributor {
+
+  @NotNull
+  @Override
+  public String getSearchProviderId() {
+    return RecentFilesSEContributor.class.getSimpleName();
+  }
+
+  @NotNull
+  @Override
+  public String getGroupName() {
+    return "Recent Files";
+  }
+
+  @Override
+  public String includeNonProjectItemsText() {
+    return null;
+  }
+
+  @Override
+  public int getSortWeight() {
+    return 70;
+  }
+
+  @Override
+  public ContributorSearchResult<Object> search(Project project, String pattern, boolean everywhere, ProgressIndicator progressIndicator, int elementsLimit) {
+    MinusculeMatcher matcher = NameUtil.buildMatcher("*" + pattern).build();
+    List<VirtualFile> opened = Arrays.asList(FileEditorManager.getInstance(project).getSelectedFiles());
+    List<VirtualFile> history = Lists.reverse(EditorHistoryManager.getInstance(project).getFileList());
+
+    PsiManager psiManager = PsiManager.getInstance(project);
+    Stream<VirtualFile> stream = history.stream();
+    if (!StringUtil.isEmptyOrSpaces(pattern)) {
+      stream = stream.filter(file -> matcher.matches(file.getName()));
+    }
+    List<Object> res = stream.filter(vf -> !opened.contains(vf) && vf.isValid())
+                             .distinct()
+                             .map(vf -> psiManager.findFile(vf))
+                             .collect(Collectors.toList());
+
+    return res.size() > elementsLimit
+           ? new ContributorSearchResult<>(res.subList(0, elementsLimit), true)
+           : new ContributorSearchResult<>(res);
+  }
+}

platform/lang-impl/src/com/intellij/ide/actions/searcheverywhere/SearchEverywhereManagerImpl.java

@@ -49,6 +49,8 @@ public class SearchEverywhereManagerImpl implements SearchEverywhereManager {
     // fill service contributors
     TopHitSEContributor topHitContributor = new TopHitSEContributor(s -> mySearchEverywhereUI.getSearchField().setText(s));
     myServiceContributors.add(topHitContributor);
+    RecentFilesSEContributor recentContributor = new RecentFilesSEContributor();
+    myServiceContributors.add(recentContributor);
   }
 
   @Override

platform/lang-impl/src/com/intellij/ide/actions/searcheverywhere/SearchEverywhereUI.java

@@ -619,7 +619,7 @@ public class SearchEverywhereUI extends BorderLayoutPanel implements Disposable,
       } else {
         boolean clearBefore = true;
         for (SearchEverywhereContributor contributor : allContributors) {
-          anyFound = anyFound || addContributorItems(contributor, MULTIPLE_CONTRIBUTORS_ELEMENTS_LIMIT, clearBefore);
+          anyFound |= addContributorItems(contributor, MULTIPLE_CONTRIBUTORS_ELEMENTS_LIMIT, clearBefore);
           clearBefore = false;
         }
       }