Revert "Revert "Fixed user login image flicker/glitch""

This reverts commit 3e1eaf1cb5ec4cf913b785c5100a539ce4cf7df9.

Change-Id: Iacc358ad4678ed55421faad98fe1a786e68d9a40

7 files changed, 127 insertions, 124 deletions

diff --git a/src/com/google/gct/login/CredentialedUserRoster.java b/src/com/google/gct/login/CredentialedUserRoster.java
index 7d50c70..d8936fb 100644
--- a/src/com/google/gct/login/CredentialedUserRoster.java
+++ b/src/com/google/gct/login/CredentialedUserRoster.java
@@ -29,22 +29,19 @@ import java.util.Map;
  * {@link CredentialedUser} objects.
  */
 public class CredentialedUserRoster {
-  private final LinkedHashMap<String, CredentialedUser> allUsers = new LinkedHashMap<String, CredentialedUser>();
-  private CredentialedUser activeUser;
-  private Collection<GoogleLoginListener> listeners;
-
-  public CredentialedUserRoster() {
-    listeners = Lists.newLinkedList();
-  }
+  private final LinkedHashMap<String, CredentialedUser> myAllUsers = new LinkedHashMap<String, CredentialedUser>();
+  private final Collection<GoogleLoginListener> myListeners = Lists.newLinkedList();
+  private CredentialedUser myActiveUser;
 
   /**
    * Returns a copy of the map of the current logged in users.
    * @return Copy of current logged in users.
    */
+  @NotNull
   public LinkedHashMap<String, CredentialedUser> getAllUsers() {
     synchronized (this) {
       LinkedHashMap<String, CredentialedUser> clone = new LinkedHashMap<String, CredentialedUser>();
-      clone.putAll(allUsers);
+      clone.putAll(myAllUsers);
       return clone;
     }
   }
@@ -55,8 +52,8 @@ public class CredentialedUserRoster {
    */
   public void setAllUsers(Map<String, CredentialedUser> users) {
     synchronized (this) {
-      allUsers.clear();
-      allUsers.putAll(users);
+      myAllUsers.clear();
+      myAllUsers.putAll(users);
     }
   }
 
@@ -66,7 +63,7 @@ public class CredentialedUserRoster {
    */
   @Nullable
   public CredentialedUser getActiveUser() {
-    return activeUser;
+    return myActiveUser;
   }
 
   /**
@@ -78,16 +75,16 @@ public class CredentialedUserRoster {
    */
   public void setActiveUser(@NotNull String userEmail) throws IllegalArgumentException {
     synchronized (this) {
-      if(!allUsers.containsKey(userEmail)) {
+      if (!myAllUsers.containsKey(userEmail)) {
         throw new IllegalArgumentException(userEmail + " is not a logged in user.");
       }
 
-      if(activeUser != null) {
-        activeUser.setActive(false);
+      if (myActiveUser != null) {
+        myActiveUser.setActive(false);
       }
 
-      activeUser = allUsers.get(userEmail);
-      activeUser.setActive(true);
+      myActiveUser = myAllUsers.get(userEmail);
+      myActiveUser.setActive(true);
       GoogleLoginPrefs.saveActiveUser(userEmail);
       notifyLoginStatusChange();
     }
@@ -98,9 +95,9 @@ public class CredentialedUserRoster {
    */
   public void removeActiveUser() {
     synchronized (this) {
-      if(activeUser != null) {
-        activeUser.setActive(false);
-        activeUser = null;
+      if (myActiveUser != null) {
+        myActiveUser.setActive(false);
+        myActiveUser = null;
         GoogleLoginPrefs.removeActiveUser();
         notifyLoginStatusChange();
       }
@@ -113,7 +110,7 @@ public class CredentialedUserRoster {
    */
   public int numberOfUsers() {
     synchronized (this) {
-      return allUsers.size();
+      return myAllUsers.size();
     }
   }
 
@@ -122,7 +119,7 @@ public class CredentialedUserRoster {
    * @return True if there is an active user and false otherwise.
    */
   public boolean isActiveUserAvailable() {
-    return activeUser != null;
+    return myActiveUser != null;
   }
 
   /**
@@ -134,7 +131,7 @@ public class CredentialedUserRoster {
    */
   public void addUser(CredentialedUser user) {
     synchronized (this) {
-      allUsers.put(user.getEmail(), user);
+      myAllUsers.put(user.getEmail(), user);
       setActiveUser(user.getEmail());
     }
   }
@@ -150,16 +147,16 @@ public class CredentialedUserRoster {
    */
   public boolean removeUser(String userEmail) {
     synchronized (this) {
-      if(!allUsers.containsKey(userEmail)) {
+      if (!myAllUsers.containsKey(userEmail)) {
         return false;
       }
 
-      if(activeUser.getEmail().equals(userEmail)) {
-        activeUser = null;
+      if (myActiveUser.getEmail().equals(userEmail)) {
+        myActiveUser = null;
         GoogleLoginPrefs.removeActiveUser();
       }
 
-      allUsers.remove(userEmail);
+      myAllUsers.remove(userEmail);
       notifyLoginStatusChange();
       return true;
     }
@@ -172,14 +169,14 @@ public class CredentialedUserRoster {
    * @param listener the specified {@code GoogleLoginListener}
    */
   void addLoginListener(GoogleLoginListener listener) {
-    synchronized(listeners) {
-      listeners.add(listener);
+    synchronized(myListeners) {
+      myListeners.add(listener);
     }
   }
 
   private void notifyLoginStatusChange() {
-    synchronized(listeners) {
-      for (GoogleLoginListener listener : listeners) {
+    synchronized(myListeners) {
+      for (GoogleLoginListener listener : myListeners) {
         listener.statusChanged();
       }
     }
diff --git a/src/com/google/gct/login/GoogleLogin.java b/src/com/google/gct/login/GoogleLogin.java
index 7ddf670..4676152 100644
--- a/src/com/google/gct/login/GoogleLogin.java
+++ b/src/com/google/gct/login/GoogleLogin.java
@@ -70,9 +70,6 @@ public class GoogleLogin {
 
   public static final Logger LOG =  Logger.getInstance(GoogleLogin.class);
 
-  /**
-   * Constructor
-   */
   private GoogleLogin() {
     this.clientInfo = getClientInfo();
     this.uiFacade = new AndroidUiFacade();
@@ -85,8 +82,9 @@ public class GoogleLogin {
    * Gets the {@link GoogleLogin} object.
    * @return the {@link GoogleLogin} object.
    */
+  @NotNull
   public static GoogleLogin getInstance() {
-    if(instance == null) {
+    if (instance == null) {
       instance = new GoogleLogin();
       instance.dataStore.initializeUsers();
     }
@@ -110,10 +108,10 @@ public class GoogleLogin {
    * either succeeds or fails.
    * @throws InvalidThreadTypeException
    */
-  public static void promptToLogIn(final String message, @Nullable final IGoogleLoginCompletedCallback callback)
+  public static void promptToLogIn(@Nullable final String message, @Nullable final IGoogleLoginCompletedCallback callback)
     throws InvalidThreadTypeException {
     if (!instance.isLoggedIn()) {
-      if(ApplicationManager.getApplication().isDispatchThread()) {
+      if (ApplicationManager.getApplication().isDispatchThread()) {
         getInstance().logIn(message, callback);
       } else {
         throw new InvalidThreadTypeException("promptToLogin");
@@ -135,6 +133,7 @@ public class GoogleLogin {
    * @return  An HttpRequestFactory object that has been signed with the active user's
    * authentication headers or null if there is no active user.
    */
+  @Nullable
   public HttpRequestFactory createRequestFactory() {
     return createRequestFactory(null);
   }
@@ -156,9 +155,10 @@ public class GoogleLogin {
    * @return  An HttpRequestFactory object that has been signed with the active user's
    * authentication headers or null if there is no active user.
    */
-  public HttpRequestFactory createRequestFactory(String message) {
+  @Nullable
+  public HttpRequestFactory createRequestFactory(@Nullable String message) {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       // TODO: prompt user to select an existing user or sign in
       return null;
     }
@@ -173,9 +173,10 @@ public class GoogleLogin {
    * @throws IOException if something goes wrong while fetching the token.
    *
    */
+  @Nullable
   public String fetchAccessToken() throws IOException {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return null;
     }
     return activeUser.getGoogleLoginState().fetchAccessToken();
@@ -185,9 +186,10 @@ public class GoogleLogin {
    * Returns the OAuth2 Client ID for the active user.
    * @return the OAuth2 Client ID for the active user.
    */
+  @Nullable
   public String fetchOAuth2ClientId() {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return null;
     }
     return activeUser.getGoogleLoginState().fetchOAuth2ClientId();
@@ -197,9 +199,10 @@ public class GoogleLogin {
    * Returns the OAuth2 Client Secret for the active user.
    * @return the OAuth2 Client Secret for the active user.
    */
+  @Nullable
   public String fetchOAuth2ClientSecret() {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return null;
     }
     return activeUser.getGoogleLoginState().fetchOAuth2ClientSecret();
@@ -212,9 +215,10 @@ public class GoogleLogin {
    *
    * @return the refresh token, or {@code null} if the user cancels out of a request to log in
    */
+  @Nullable
   public String fetchOAuth2RefreshToken() {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return null;
     }
     return activeUser.getGoogleLoginState().fetchOAuth2RefreshToken();
@@ -229,9 +233,10 @@ public class GoogleLogin {
    * @throws IOException if something goes wrong while fetching the token.
    *
    */
+  @Nullable
   public String fetchOAuth2Token() throws IOException {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return null;
     }
     return activeUser.getGoogleLoginState().fetchOAuth2Token();
@@ -242,9 +247,10 @@ public class GoogleLogin {
    * returns credentials with the access token and refresh token set to null.
    * @return the OAuth credentials.
    */
+  @Nullable
   public Credential getCredential() {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return null;
     }
     return activeUser.getGoogleLoginState().getCredential();
@@ -254,9 +260,10 @@ public class GoogleLogin {
    * Returns the active user's email address, or null if there is no active user,
    * @return the active user's email address, or null if there is no active user,
    */
+  @Nullable
   public String getEmail() {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return null;
     }
     return activeUser.getGoogleLoginState().getEmail();
@@ -331,7 +338,7 @@ public class GoogleLogin {
           }
         });
 
-        loggedIn = state.logInWithLocalServer(message);
+        loggedIn = state != null && state.logInWithLocalServer(message);
       }
 
       @Override
@@ -383,7 +390,7 @@ public class GoogleLogin {
    */
   public boolean logOut() {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return false;
     }
 
@@ -405,7 +412,7 @@ public class GoogleLogin {
    */
   public boolean logOut(boolean showPrompt) {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return false;
     }
     return activeUser.getGoogleLoginState().logOut(showPrompt);
@@ -417,13 +424,13 @@ public class GoogleLogin {
    * the access and refresh token will be set to null.
    * @return a new {@link Credential}.
    */
+  @Nullable
   public Credential makeCredential() {
     CredentialedUser activeUser = users.getActiveUser();
-    if(activeUser == null) {
+    if (activeUser == null) {
       return null;
-    } else {
-      return activeUser.getGoogleLoginState().makeCredential();
     }
+    return activeUser.getGoogleLoginState().makeCredential();
   }
 
   /**
@@ -502,7 +509,7 @@ public class GoogleLogin {
         uiFacade,
         new AndroidLoggerFacade());
 
-    if(initializingUsers && !state.isLoggedIn()) {
+    if (initializingUsers && !state.isLoggedIn()) {
       // Logs user out if oauth scope for active user's credentials
       // does not match the current scope
       return null;
@@ -515,7 +522,7 @@ public class GoogleLogin {
    * Returns the Client Info for Android Studio in a {@link com.google.gct.login.GoogleLogin.ClientInfo}.
    * @return the Client Info for Android Studio in a {@link com.google.gct.login.GoogleLogin.ClientInfo}.
    */
-  private ClientInfo getClientInfo() {
+  private static ClientInfo getClientInfo() {
       String id = LoginContext.getId();
       String info = LoginContext.getInfo();
       if (id != null && id.trim().length() > 0
@@ -527,7 +534,7 @@ public class GoogleLogin {
   }
 
   // TODO: update code to specify parent
-  private void logErrorAndDisplayDialog(@NotNull final String title, @NotNull final Exception exception) {
+  private static void logErrorAndDisplayDialog(@NotNull final String title, @NotNull final Exception exception) {
     LOG.error(exception.getMessage(), exception);
     GoogleLoginUtils.showErrorDialog(exception.getMessage(), title);
   }
@@ -627,13 +634,17 @@ public class GoogleLogin {
     @Override
     public boolean askYesOrNo(String title, String message) {
       String updatedMessage = message;
-      if(message.equals("Are you sure you want to sign out?")) {
+      if (message.equals("Are you sure you want to sign out?")) {
+        updatedMessage = "Are you sure you want to sign out";
         CredentialedUser activeUser = getActiveUser();
-        String name = activeUser.getName().isEmpty() ? "" : activeUser.getName() + " ";
-        updatedMessage = "Are you sure you want to sign out " + name
-          + "(" + activeUser.getEmail() + ")?";
+        if (activeUser != null && !Strings.isNullOrEmpty(activeUser.getName())) {
+          updatedMessage += (" " + activeUser.getName());
+        }
+        if (activeUser != null && !Strings.isNullOrEmpty(activeUser.getEmail())) {
+          updatedMessage += (" (" + activeUser.getEmail() + ")");
+        }
+        updatedMessage += "?";
       }
-
       Icon icon = IconLoader.getIcon(GOOGLE_IMG);
       return (Messages.showYesNoDialog(updatedMessage, title, icon) == Messages.YES);
     }
@@ -685,7 +696,7 @@ public class GoogleLogin {
       List<String> allUsers = GoogleLoginPrefs.getStoredUsers();
       String removedUsers = "";
 
-      for(String aUser : allUsers) {
+      for (String aUser : allUsers) {
         // Add a new user, so that loadOAuth called from the GoogleLoginState constructor
         // will be able to create a customized key to get that user's OAuth data
         // This will be overwritten with new GoogleLoginState object
@@ -728,9 +739,8 @@ public class GoogleLogin {
       }
 
       // Log removed users
-      if(!removedUsers.isEmpty()) {
-        String message = "The following user(s) had expired authentication scopes: " + removedUsers
-          + "and have been logged out.";
+      if (!removedUsers.isEmpty()) {
+        String message = "The following user(s) had expired authentication scopes: " + removedUsers + "and have been logged out.";
         GoogleLoginUtils.showErrorDialog(message, "Google Login");
       }
     }
diff --git a/src/com/google/gct/login/GoogleLoginListener.java b/src/com/google/gct/login/GoogleLoginListener.java
index 560f5f0..84f1778 100644
--- a/src/com/google/gct/login/GoogleLoginListener.java
+++ b/src/com/google/gct/login/GoogleLoginListener.java
@@ -21,8 +21,7 @@ import com.intellij.openapi.extensions.ExtensionPointName;
  * Listener for changes in the login status.
  */
 public interface GoogleLoginListener {
-  public static ExtensionPointName<GoogleLoginListener> EP_NAME =
-    new ExtensionPointName<GoogleLoginListener>("com.google.gct.login.googleLoginListener");
+  ExtensionPointName<GoogleLoginListener> EP_NAME = new ExtensionPointName<GoogleLoginListener>("com.google.gct.login.googleLoginListener");
 
   /**
    * Called when the login or active status of the user changes.
diff --git a/src/com/google/gct/login/GoogleLoginPrefs.java b/src/com/google/gct/login/GoogleLoginPrefs.java
index 1872f4e..0c9afd0 100644
--- a/src/com/google/gct/login/GoogleLoginPrefs.java
+++ b/src/com/google/gct/login/GoogleLoginPrefs.java
@@ -18,10 +18,12 @@ package com.google.gct.login;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Joiner;
 import com.google.common.base.Splitter;
+import com.google.common.collect.Lists;
 import com.google.gdt.eclipse.login.common.OAuthData;
 
 import com.intellij.openapi.diagnostic.Logger;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -184,6 +186,7 @@ public class GoogleLoginPrefs {
    * Retrieves the persistently stored active user.
    * @return the stored active user.
    */
+  @Nullable
   public static String getActiveUser() {
     Preferences prefs = getPrefs();
     String activeUser = prefs.get(ACTIVE_USER, null);
@@ -250,9 +253,9 @@ public class GoogleLoginPrefs {
     flushPrefs(prefs);
   }
 
-  private static void removeUser(Preferences prefs, String user) {;
+  private static void removeUser(Preferences prefs, String user) {
     String allUsersString = prefs.get(USERS, "");
-    List<String> allUsers = new ArrayList<String>();
+    List<String> allUsers = Lists.newArrayList();
     for (String scope : allUsersString.split(DELIMITER)) {
       allUsers.add(scope);
     }
diff --git a/src/com/google/gct/login/GoogleLoginUtils.java b/src/com/google/gct/login/GoogleLoginUtils.java
index adf1777..11a29a9 100644
--- a/src/com/google/gct/login/GoogleLoginUtils.java
+++ b/src/com/google/gct/login/GoogleLoginUtils.java
@@ -51,7 +51,6 @@ public class GoogleLoginUtils {
    * @param pictureCallback
    * @return the user's picture from <code>userInfo</code>
    */
-  @Nullable
   public static void getUserPicture(Userinfoplus userInfo, final IUserPropertyCallback pictureCallback) {
     // set the size of the image before it is served
     String urlString = userInfo.getPicture() + "?sz=" + DEFAULT_PICTURE_SIZE;
@@ -76,7 +75,6 @@ public class GoogleLoginUtils {
     });
   }
 
-  @Nullable
   public static void getUserInfo(@NotNull final Credential credential,
     final IUserPropertyCallback callback) {
     final Oauth2 userInfoService =
@@ -131,6 +129,7 @@ public class GoogleLoginUtils {
    * Used for testing.
    * @return a {@link Credential} object for the fake user.
    */
+  @NotNull
   public static Credential makeFakeUserCredential() {
     String clientId = System.getenv().get("ANDROID_CLIENT_ID");
     String clientSecret = System.getenv().get("ANDROID_CLIENT_SECRET");
diff --git a/src/com/google/gct/login/OAuthScopeRegistry.java b/src/com/google/gct/login/OAuthScopeRegistry.java
index a0c23b5..31f96c7 100644
--- a/src/com/google/gct/login/OAuthScopeRegistry.java
+++ b/src/com/google/gct/login/OAuthScopeRegistry.java
@@ -15,8 +15,6 @@
  */
 package com.google.gct.login;
 
-
-import com.intellij.util.containers.HashSet;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.Collections;
@@ -27,19 +25,18 @@ import java.util.TreeSet;
  * Holds the list of OAuth2 scopes for Google Login.
  */
 class OAuthScopeRegistry {
-  private static final SortedSet<String> sScopes;
+  private static final SortedSet<String> SCOPES;
 
   static {
     SortedSet<String> scopes = new TreeSet<String>();
     scopes.add("https://www.googleapis.com/auth/userinfo#email");
     scopes.add("https://www.googleapis.com/auth/appengine.admin");
     scopes.add("https://www.googleapis.com/auth/cloud-platform");
-
-    sScopes = Collections.unmodifiableSortedSet(scopes);
+    SCOPES = Collections.unmodifiableSortedSet(scopes);
   }
 
   @NotNull
   public static SortedSet<String> getScopes() {
-    return sScopes;
+    return SCOPES;
   }
 }
diff --git a/src/com/google/gct/login/ui/UsersListCellRenderer.java b/src/com/google/gct/login/ui/UsersListCellRenderer.java
index 928eeba..01e319a 100644
--- a/src/com/google/gct/login/ui/UsersListCellRenderer.java
+++ b/src/com/google/gct/login/ui/UsersListCellRenderer.java
@@ -16,6 +16,9 @@
 package com.google.gct.login.ui;
 
 import com.intellij.ui.ColorUtil;
+import com.google.api.client.util.Maps;
+import com.google.gct.login.CredentialedUser;
+import com.google.gct.login.GoogleLogin;
 import com.intellij.ui.JBColor;
 import com.intellij.util.ui.UIUtil;
 import org.jetbrains.annotations.Nullable;
@@ -42,7 +45,7 @@ import java.awt.Image;
 import java.awt.Point;
 import java.awt.Toolkit;
 import java.net.URL;
-
+import java.util.Map;
 
 /**
  * A custom cell render for {@link GoogleLoginUsersPanel#list} that manages
@@ -82,6 +85,11 @@ public class UsersListCellRenderer extends JComponent implements ListCellRendere
   private final Dimension myPlayLabelDimension;
   private final Dimension myLearnMoreLabelDimension;
 
+  /** Maps user emails to large user image icons. */
+  private final Map<String, Image> myUserLargeImageCache = Maps.newHashMap();
+  /** Maps user emails to small user image icons. */
+  private final Map<String, Image> myUserSmallImageCache = Maps.newHashMap();
+
   public UsersListCellRenderer() {
     myNameFont = new Font("Helvetica", Font.BOLD, 13);
     myGeneralFont = new Font("Helvetica", Font.PLAIN, 13);
@@ -101,49 +109,58 @@ public class UsersListCellRenderer extends JComponent implements ListCellRendere
   @Nullable
   @Override
   public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
-    if(value instanceof NoUsersListItem) {
+    if (value instanceof NoUsersListItem) {
       return createNoUserDisplay();
     }
-
-    if(!(value instanceof UsersListItem)) {
+    if (!(value instanceof UsersListItem)) {
       return null;
     }
-    UsersListItem usersListItem = (UsersListItem)value;
 
-    boolean calcIsSelected;
-    if (list.getSelectedIndex() == index) {
-      calcIsSelected = true;
-    } else {
-      calcIsSelected = false;
-    }
+    final UsersListItem usersListItem = (UsersListItem)value;
+    final CredentialedUser activeUser = GoogleLogin.getInstance().getActiveUser();
+    final boolean isActiveUserSelected = activeUser != null && usersListItem.getUserEmail().equals(activeUser.getEmail());
 
     JPanel mainPanel = new JPanel(new FlowLayout(FlowLayout.LEFT, HGAP, VGAP));
-    mainPanel.setMinimumSize(calcIsSelected ? myActiveMainPanelDimension : myMainPanelDimension);
+    mainPanel.setMinimumSize(isActiveUserSelected ? myActiveMainPanelDimension : myMainPanelDimension);
     mainPanel.setAlignmentX(LEFT_ALIGNMENT);
 
     // Update colors
-    final Color bg = calcIsSelected ? myActiveColor : myInactiveColor;
-    final Color fg = calcIsSelected ? UIUtil.getListSelectionForeground() : UIUtil.getListForeground();
+    final Color bg = isActiveUserSelected ? myActiveColor : myInactiveColor;
+    final Color fg = isActiveUserSelected ? UIUtil.getListSelectionForeground() : UIUtil.getListForeground();
     mainPanel.setBackground(bg);
     mainPanel.setForeground(fg);
 
-    // TODO: add step to cache scaled image
     Image image = usersListItem.getUserPicture();
-    if(image == null){
-      // use default image
-      URL url = UsersListCellRenderer.class.getResource(DEFAULT_AVATAR);
-      image = Toolkit.getDefaultToolkit().getImage(url);
+    if (image == null){
+      // Use default profile image.
+      image = Toolkit.getDefaultToolkit().getImage(UsersListCellRenderer.class.getResource(DEFAULT_AVATAR));
     }
 
-    int imageWidth = calcIsSelected ? ACTIVE_USER_IMAGE_WIDTH : PLAIN_USER_IMAGE_WIDTH;
-    int imageHeight = calcIsSelected ? ACTIVE_USER_IMAGE_HEIGHT : PLAIN_USER_IMAGE_HEIGHT;
-    Image scaledImage = image.getScaledInstance(imageWidth, imageHeight, Image.SCALE_SMOOTH);
+    final int imageWidth, imageHeight;
+    final Map<String, Image> userImageCache;
+    if (isActiveUserSelected) {
+      imageWidth = ACTIVE_USER_IMAGE_WIDTH;
+      imageHeight = ACTIVE_USER_IMAGE_HEIGHT;
+      userImageCache = myUserLargeImageCache;
+    } else {
+      imageWidth = PLAIN_USER_IMAGE_WIDTH;
+      imageHeight = PLAIN_USER_IMAGE_HEIGHT;
+      userImageCache = myUserSmallImageCache;
+    }
+
+    final Image scaledImage;
+    if (!userImageCache.containsKey(usersListItem.getUserEmail())) {
+      scaledImage = image.getScaledInstance(imageWidth, imageHeight, Image.SCALE_SMOOTH);
+      userImageCache.put(usersListItem.getUserEmail(), scaledImage);
+    } else {
+      scaledImage = userImageCache.get(usersListItem.getUserEmail());
+    }
 
-    JComponent textPanel;
-    if (calcIsSelected) {
-      textPanel =  createActiveTextDisplay(usersListItem);
+    final JComponent textPanel;
+    if (isActiveUserSelected) {
+      textPanel = createActiveTextDisplay(usersListItem);
     } else {
-      textPanel =  createTextDisplay(calcIsSelected, usersListItem);
+      textPanel = createTextDisplay(false, usersListItem);
     }
 
     mainPanel.add(new JLabel(new ImageIcon(scaledImage)));
@@ -161,13 +178,7 @@ public class UsersListCellRenderer extends JComponent implements ListCellRendere
     double playYEnd = playYStart + myPlayLabelDimension.getHeight();
     double playXStart = ACTIVE_USER_IMAGE_WIDTH + HGAP + VGAP;
     double playXEnd = playXStart + myPlayLabelDimension.getWidth();
-
-    if((point.getX() > playXStart) && (point.getX() < playXEnd)
-       && (point.getY() > playYStart) && (point.getY() < playYEnd)) {
-      return true;
-    }
-
-    return false;
+    return (point.getX() > playXStart) && (point.getX() < playXEnd) && (point.getY() > playYStart) && (point.getY() < playYEnd);
   }
 
   public boolean inCloudConsoleUrl(Point point, int activeIndex) {
@@ -177,13 +188,7 @@ public class UsersListCellRenderer extends JComponent implements ListCellRendere
     double playYEnd = playYStart + myCloudLabelDimension.getHeight();
     double playXStart = ACTIVE_USER_IMAGE_WIDTH + HGAP + VGAP;
     double playXEnd = playXStart + myCloudLabelDimension.getWidth();
-
-    if((point.getX() > playXStart) && (point.getX() < playXEnd)
-       && (point.getY() > playYStart) && (point.getY() < playYEnd)) {
-      return true;
-    }
-
-    return false;
+    return (point.getX() > playXStart) && (point.getX() < playXEnd) && (point.getY() > playYStart) && (point.getY() < playYEnd);
   }
 
   public boolean inLearnMoreUrl(Point point) {
@@ -193,13 +198,7 @@ public class UsersListCellRenderer extends JComponent implements ListCellRendere
     double urlYEnd = urlYStart + myLearnMoreLabelDimension.getHeight();
     double urlXStart = GOOGLE_IMAGE_WEST;
     double urlXEnd = urlXStart + myLearnMoreLabelDimension.getWidth();
-
-    if((point.getX() > urlXStart) && (point.getX() < urlXEnd)
-       && (point.getY() > urlYStart) && (point.getY() < urlYEnd)) {
-      return true;
-    }
-
-    return false;
+    return (point.getX() > urlXStart) && (point.getX() < urlXEnd) && (point.getY() > urlYStart) && (point.getY() < urlYEnd);
   }
 
   public int getMainPanelHeight() {
@@ -286,8 +285,7 @@ public class UsersListCellRenderer extends JComponent implements ListCellRendere
     String googleIcon = UIUtil.isUnderDarcula() ? GOOGLE_IMG_WHITE : GOOGLE_IMG_COL;
     URL url = UsersListCellRenderer.class.getResource(googleIcon);
     Image image = Toolkit.getDefaultToolkit().getImage(url);
-    Image scaledImage = image.getScaledInstance(
-      GOOGLE_IMAGE_WIDTH, GOOGLE_IMAGE_HEIGHT, Image.SCALE_SMOOTH);
+    Image scaledImage = image.getScaledInstance(GOOGLE_IMAGE_WIDTH, GOOGLE_IMAGE_HEIGHT, Image.SCALE_SMOOTH);
     JLabel imageLabel = new JLabel(new ImageIcon(scaledImage));
 
     JLabel signInLabel = new JLabel(SIGN_IN_TEXT);