In-application Keystone ticket promotion

chrome/browser/cocoa/about_window_controller.mm

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#import "chrome/browser/cocoa/about_window_controller.h"
+
 #include "app/l10n_util_mac.h"
 #include "app/resource_bundle.h"
 #include "base/logging.h"
 #include "base/mac_util.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
-#import "chrome/app/keystone_glue.h"
 #include "chrome/browser/browser_list.h"
-#import "chrome/browser/cocoa/about_window_controller.h"
 #import "chrome/browser/cocoa/background_tile_view.h"
+#import "chrome/browser/cocoa/keystone_glue.h"
 #include "chrome/browser/cocoa/restart_browser.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "grit/locale_settings.h"
 #include "third_party/GTM/AppKit/GTMUILocalizerAndLayoutTweaker.h"
 
 namespace {
 
 void AttributedStringAppendString(NSMutableAttributedString* attr_str,
@@ skipping 27 matching lines @@
                    range:range];
 }
 
 }  // namespace
 
 @interface AboutWindowController(Private)
 
 // Launches a check for available updates.
 - (void)checkForUpdate;
 
+// Turns the update and promotion blocks on and off as needed based on whether
+// updates are possible and promotion is desired or required.
+- (void)adjustUpdateUIVisibility;
+
+// Maintains the update and promotion block visibility and window sizing.
+// This uses bool instead of BOOL for the convenience of the internal
+// implementation.
+- (void)setAllowsUpdate:(bool)update allowsPromotion:(bool)promotion;
+
 // Notification callback, called with the status of asynchronous
 // -checkForUpdate and -updateNow: operations.
 - (void)updateStatus:(NSNotification*)notification;
 
 // These methods maintain the image (or throbber) and text displayed regarding
 // update status.  -setUpdateThrobberMessage: starts a progress throbber and
 // sets the text.  -setUpdateImage:message: displays an image and sets the
 // text.
 - (void)setUpdateThrobberMessage:(NSString*)message;
 - (void)setUpdateImage:(int)imageID message:(NSString*)message;
@@ skipping 27 matching lines @@
 }
 
 - (void)dealloc {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   [super dealloc];
 }
 
 // YES when an About box is currently showing the kAutoupdateInstallFailed
 // status, or if no About box is visible, if the most recent About box to be
 // closed was closed while showing this status.  When an About box opens, if
-// the recent status is kAutoupdateInstallFailed and
-// recentShownInstallFailedStatus is NO, the failure needs to be shown instead
-// of launching a new update check.  recentShownInstallFailedStatus is
+// the recent status is kAutoupdateInstallFailed or kAutoupdatePromoteFailed
+// and recentShownUserActionFailedStatus is NO, the failure needs to be shown
+// instead of launching a new update check.  recentShownInstallFailedStatus is
 // maintained by -updateStatus:.
-static BOOL recentShownInstallFailedStatus = NO;
+static BOOL recentShownUserActionFailedStatus = NO;
 
 - (void)awakeFromNib {
   NSBundle* bundle = mac_util::MainAppBundle();
   NSString* chromeVersion =
       [bundle objectForInfoDictionaryKey:@"CFBundleShortVersionString"];
 
 #if defined(GOOGLE_CHROME_BUILD)
   NSString* version = chromeVersion;
 #else  // GOOGLE_CHROME_BUILD
   // The format string is not localized, but this is how the displayed version
@@ skipping 15 matching lines @@
   [logoView_ setImage:logoImage];
 
   [[legalText_ textStorage] setAttributedString:[[self class] legalTextBlock]];
 
   // Resize our text view now so that the |updateShift| below is set
   // correctly. The About box has its controls manually positioned, so we need
   // to calculate how much larger (or smaller) our text box is and store that
   // difference in |legalShift|. We do something similar with |updateShift|
   // below, which is either 0, or the amount of space to offset the window size
   // because the view that contains the update button has been removed because
-  // this build doesn't have KeyStone.
+  // this build doesn't have Keystone.
   NSRect oldLegalRect = [legalBlock_ frame];
   [legalText_ sizeToFit];
   NSRect newRect = oldLegalRect;
   newRect.size.height = [legalText_ frame].size.height;
   [legalBlock_ setFrame:newRect];
   CGFloat legalShift = newRect.size.height - oldLegalRect.size.height;
 
-  KeystoneGlue* keystoneGlue = [KeystoneGlue defaultKeystoneGlue];
-  CGFloat updateShift;
-  if (keystoneGlue) {
+  NSRect backgroundFrame = [backgroundView_ frame];
+  backgroundFrame.origin.y += legalShift;
+  [backgroundView_ setFrame:backgroundFrame];
+
+  NSSize windowDelta = NSMakeSize(0.0, legalShift);
+  [GTMUILocalizerAndLayoutTweaker
+      resizeWindowWithoutAutoResizingSubViews:[self window]
+                                        delta:windowDelta];
+
+  windowHeight_ = [[self window] frame].size.height;
+
+  [self adjustUpdateUIVisibility];
+
+  // Don't do anything update-related if adjustUpdateUIVisibility decided that
+  // updates aren't possible.
+  if (![updateBlock_ isHidden]) {
+    KeystoneGlue* keystoneGlue = [KeystoneGlue defaultKeystoneGlue];
+    AutoupdateStatus recentStatus = [keystoneGlue recentStatus];
     if ([keystoneGlue asyncOperationPending] ||
-        ([keystoneGlue recentStatus] == kAutoupdateInstallFailed &&
-         !recentShownInstallFailedStatus)) {
+        recentStatus == kAutoupdateRegisterFailed ||
+        ((recentStatus == kAutoupdateInstallFailed ||
+          recentStatus == kAutoupdatePromoteFailed) &&
+         !recentShownUserActionFailedStatus)) {
       // If an asynchronous update operation is currently pending, such as a
       // check for updates or an update installation attempt, set the status
       // up correspondingly without launching a new update check.
       //
-      // If a previous update attempt was unsuccessful but no About box was
-      // around to report the error, show it now, and allow another chance to
-      // install the update.
+      // If registration failed, no other operations make sense, so just go
+      // straight to the error.
+      //
+      // If a previous update or promotion attempt was unsuccessful but no
+      // About box was around to report the error, show it now, and allow
+      // another chance to perform the action.
       [self updateStatus:[keystoneGlue recentNotification]];
     } else {
       // Launch a new update check, even if one was already completed, because
       // a new update may be available or a new update may have been installed
       // in the background since the last time an About box was displayed.
       [self checkForUpdate];
     }
-
-    updateShift = 0.0;
-  } else {
-    // Hide all the update UI
-    [updateBlock_ setHidden:YES];
-
-    // Figure out the amount being removed by taking out the update block
-    // and its spacing.
-    updateShift = NSMinY([legalBlock_ frame]) - NSMinY([updateBlock_ frame]);
-
-    NSRect legalFrame = [legalBlock_ frame];
-    legalFrame.origin.y -= updateShift;
-    [legalBlock_ setFrame:legalFrame];
   }
 
-  NSRect backgroundFrame = [backgroundView_ frame];
-  backgroundFrame.origin.y += legalShift - updateShift;
-  [backgroundView_ setFrame:backgroundFrame];
-
-  NSSize windowDelta = NSMakeSize(0.0, legalShift - updateShift);
-
-  [GTMUILocalizerAndLayoutTweaker
-      resizeWindowWithoutAutoResizingSubViews:[self window]
-                                        delta:windowDelta];
+  [[self window] center];
 }
 
 - (void)windowWillClose:(NSNotification*)notification {
   [self autorelease];
 }
 
+- (void)adjustUpdateUIVisibility {
+  bool allowUpdate;
+  bool allowPromotion;
+
+  KeystoneGlue* keystoneGlue = [KeystoneGlue defaultKeystoneGlue];
+  if (keystoneGlue && ![keystoneGlue isOnReadOnlyFilesystem]) {
+    AutoupdateStatus recentStatus = [keystoneGlue recentStatus];
+    if (recentStatus == kAutoupdateRegistering ||
+        recentStatus == kAutoupdateRegisterFailed ||
+        recentStatus == kAutoupdatePromoted) {
+      // Show the update block while registering so that there's a progress
+      // spinner, and if registration failed so that there's an error message.
+      // Show it following a promotion because updates should be possible
+      // after promotion successfully completes.
+      allowUpdate = true;
+
+      // Promotion isn't possible at this point.
+      allowPromotion = false;
+    } else if (recentStatus == kAutoupdatePromoteFailed) {
+      // TODO(mark): Add kAutoupdatePromoting to this block.  KSRegistration
+      // currently handles the promotion synchronously, meaning that the main
+      // thread's loop doesn't spin, meaning that animations and other updates
+      // to the window won't occur until KSRegistration is done with
+      // promotion.  This looks laggy and bad and probably qualifies as
+      // "jank."  For now, there just won't be any visual feedback while
+      // promotion is in progress, but it should complete (or fail) very
+      // quickly.  http://b/2290009.
+      //
+      // Also see the TODO for kAutoupdatePromoting in -updateStatus:version:.
+      //
+      // Show the update block so that there's some visual feedback that
+      // promotion is under way or that it's failed.  Show the promotion block
+      // because the user either just clicked that button or because the user
+      // should be able to click it again.
+      allowUpdate = true;
+      allowPromotion = true;
+    } else {
+      // Show the update block only if a promotion is not absolutely required.
+      allowUpdate = ![keystoneGlue needsPromotion];
+
+      // Show the promotion block if promotion is a possibility.
+      allowPromotion = [keystoneGlue wantsPromotion];
+    }
+  } else {
+    // There is no glue, or the application is on a read-only filesystem.
+    // Updates and promotions are impossible.
+    allowUpdate = false;
+    allowPromotion = false;
+  }
+
+  [self setAllowsUpdate:allowUpdate allowsPromotion:allowPromotion];
+}
+
+- (void)setAllowsUpdate:(bool)update allowsPromotion:(bool)promotion {
+  bool oldUpdate = ![updateBlock_ isHidden];
+  bool oldPromotion = ![promotionBlock_ isHidden];
+
+  if (promotion == oldPromotion && update == oldUpdate) {
+    return;
+  }
+
+  NSRect updateFrame = [updateBlock_ frame];
+  NSRect promotionFrame = [promotionBlock_ frame];
+
+  // This routine assumes no space between the update and promotion blocks.
+  DCHECK_EQ(NSMinY(updateFrame), NSMaxY(promotionFrame));
+
+  bool promotionOnly = !update && promotion;
+  bool oldPromotionOnly = !oldUpdate && oldPromotion;
+  if (promotionOnly != oldPromotionOnly) {
+    // The window is transitioning from having a promotion block and no update
+    // block to any other state, or the other way around.  Move the promotion
+    // frame up so that its top edge is in the same position as the update
+    // frame's top edge, or move it back down to its original location.
+    promotionFrame.origin.y += (promotionOnly ? 1.0 : -1.0) *
+                               NSHeight(updateFrame);
+  }
+
+  CGFloat delta = 0.0;
+
+  if (update != oldUpdate) {
+    [updateBlock_ setHidden:!update];
+    delta += (update ? 1.0 : -1.0) * NSHeight(updateFrame);
+  }
+
+  if (promotion != oldPromotion) {
+    [promotionBlock_ setHidden:!promotion];
+    delta += (promotion ? 1.0 : -1.0) * NSHeight(promotionFrame);
+  }
+
+  NSRect legalFrame = [legalBlock_ frame];
+
+  bool updateOrPromotion = update || promotion;
+  bool oldUpdateOrPromotion = oldUpdate || oldPromotion;
+  if (updateOrPromotion != oldUpdateOrPromotion) {
+    // The window is transitioning from having an update or promotion block or
+    // both to not having either, or the other way around.  Adjust delta to
+    // account for the space between the legal block and the update or
+    // promotion block.  When the update and promotion blocks are not visible,
+    // this extra spacing is not used.
+    delta += (updateOrPromotion ? 1.0 : -1.0) *
+             (NSMinY(legalFrame) - NSMaxY(updateFrame));
+  }
+
+  // The promotion frame may have changed even if delta is 0, so always reset
+  // its frame.
+  promotionFrame.origin.y += delta;
+  [promotionBlock_ setFrame:promotionFrame];
+
+  if (delta) {
+    updateFrame.origin.y += delta;
+    [updateBlock_ setFrame:updateFrame];
+
+    legalFrame.origin.y += delta;
+    [legalBlock_ setFrame:legalFrame];
+
+    NSRect backgroundFrame = [backgroundView_ frame];
+    backgroundFrame.origin.y += delta;
+    [backgroundView_ setFrame:backgroundFrame];
+
+    // GTMUILocalizerAndLayoutTweaker resizes the window without any
+    // opportunity for animation.  In order to animate, disable window
+    // updates, save the current frame, let GTMUILocalizerAndLayoutTweaker do
+    // its thing, save the desired frame, restore the original frame, and then
+    // animate.
+    NSWindow* window = [self window];
+    [window disableScreenUpdatesUntilFlush];
+
+    NSRect oldFrame = [window frame];
+
+    // GTMUILocalizerAndLayoutTweaker applies its delta to the window's
+    // current size (like oldFrame.size), but oldFrame isn't trustworthy if
+    // an animation is in progress.  Set the window's frame to
+    // intermediateFrame, which is a frame of the size that an existing
+    // animation is animating to, so that GTM can apply the delta to the right
+    // size.
+    NSRect intermediateFrame = oldFrame;
+    intermediateFrame.origin.y -= intermediateFrame.size.height - windowHeight_;
+    intermediateFrame.size.height = windowHeight_;
+    [window setFrame:intermediateFrame display:NO];
+
+    NSSize windowDelta = NSMakeSize(0.0, delta);
+    [GTMUILocalizerAndLayoutTweaker
+        resizeWindowWithoutAutoResizingSubViews:window
+                                          delta:windowDelta];
+    [window setFrameTopLeftPoint:NSMakePoint(NSMinX(intermediateFrame),
+                                             NSMaxY(intermediateFrame))];
+    NSRect newFrame = [window frame];
+
+    windowHeight_ += delta;
+
+    if (![[self window] isVisible]) {
+      // Don't animate if the window isn't on screen yet.
+      [window setFrame:newFrame display:NO];
+    } else {
+      [window setFrame:oldFrame display:NO];
+      [window setFrame:newFrame display:YES animate:YES];
+    }
+  }
+}
+
 - (void)setUpdateThrobberMessage:(NSString*)message {
   [updateStatusIndicator_ setHidden:YES];
 
   [spinner_ setHidden:NO];
   [spinner_ startAnimation:self];
 
   [updateText_ setStringValue:message];
 }
 
 - (void)setUpdateImage:(int)imageID message:(NSString*)message {
@@ skipping 14 matching lines @@
 
   // Immediately, kAutoupdateStatusNotification will be posted, and
   // -updateStatus: will be called with status kAutoupdateChecking.
   //
   // Upon completion, kAutoupdateStatusNotification will be posted, and
   // -updateStatus: will be called with a status indicating the result of the
   // check.
 }
 
 - (IBAction)updateNow:(id)sender {
-  updateTriggered_ = YES;
-
   [[KeystoneGlue defaultKeystoneGlue] installUpdate];
 
   // Immediately, kAutoupdateStatusNotification will be posted, and
   // -updateStatus: will be called with status kAutoupdateInstalling.
   //
   // Upon completion, kAutoupdateStatusNotification will be posted, and
   // -updateStatus: will be called with a status indicating the result of the
   // installation attempt.
 }
 
+- (IBAction)promoteUpdater:(id)sender {
+  [[KeystoneGlue defaultKeystoneGlue] promoteTicket];
+
+  // Immediately, kAutoupdateStatusNotification will be posted, and
+  // -updateStatus: will be called with status kAutoupdatePromoting.
+  //
+  // Upon completion, kAutoupdateStatusNotification will be posted, and
+  // -updateStatus: will be called with a status indicating a result of the
+  // installation attempt.
+  //
+  // If the promotion was successful, KeystoneGlue will re-register the ticket
+  // and -updateStatus: will be called again indicating first that
+  // registration is in progress and subsequently that it has completed.
+}
+
 - (void)updateStatus:(NSNotification*)notification {
-  recentShownInstallFailedStatus = NO;
+  recentShownUserActionFailedStatus = NO;
 
   NSDictionary* dictionary = [notification userInfo];
   AutoupdateStatus status = static_cast<AutoupdateStatus>(
       [[dictionary objectForKey:kAutoupdateStatusStatus] intValue]);
 
   // Don't assume |version| is a real string.  It may be nil.
   NSString* version = [dictionary objectForKey:kAutoupdateStatusVersion];
 
+  bool updateMessage = true;
   bool throbber = false;
   int imageID = 0;
   NSString* message;
+  bool enableUpdateButton = false;
+  bool enablePromoteButton = true;
 
   switch (status) {
+    case kAutoupdateRegistering:
+      // When registering, use the "checking" message.  The check will be
+      // launched if appropriate immediately after registration.
+      throbber = true;
+      message = l10n_util::GetNSStringWithFixup(IDS_UPGRADE_CHECK_STARTED);
+      enablePromoteButton = false;
+
+      break;
+
+    case kAutoupdateRegistered:
+      // Once registered, the ability to update and promote is known.
+      [self adjustUpdateUIVisibility];
+
+      if (![updateBlock_ isHidden]) {
+        // If registration completes while the window is visible, go straight
+        // into an update check.  Return immediately, this routine will be
+        // re-entered shortly with kAutoupdateChecking.
+        [self checkForUpdate];
+        return;
+      }
+
+      // Nothing actually failed, but updates aren't possible.  The throbber
+      // and message are hidden, but they'll be reset to these dummy values
+      // just to get the throbber to stop spinning if it's running.
+      imageID = IDR_UPDATE_FAIL;
+      message = l10n_util::GetNSStringFWithFixup(IDS_UPGRADE_ERROR,
+                                                 IntToString16(status));
+
+      break;
+
     case kAutoupdateChecking:
       throbber = true;
       message = l10n_util::GetNSStringWithFixup(IDS_UPGRADE_CHECK_STARTED);
+      enablePromoteButton = false;
 
       break;
 
     case kAutoupdateCurrent:
       imageID = IDR_UPDATE_UPTODATE;
       message = l10n_util::GetNSStringFWithFixup(
           IDS_UPGRADE_ALREADY_UP_TO_DATE,
           l10n_util::GetStringUTF16(IDS_PRODUCT_NAME),
           base::SysNSStringToUTF16(version));
 
       break;
 
     case kAutoupdateAvailable:
       imageID = IDR_UPDATE_AVAILABLE;
       message = l10n_util::GetNSStringFWithFixup(
           IDS_UPGRADE_AVAILABLE, l10n_util::GetStringUTF16(IDS_PRODUCT_NAME));
-      [updateNowButton_ setEnabled:YES];
+      enableUpdateButton = true;
 
       break;
 
     case kAutoupdateInstalling:
-      // Don't let anyone click "Update Now" twice.
-      [updateNowButton_ setEnabled:NO];
-
       throbber = true;
       message = l10n_util::GetNSStringWithFixup(IDS_UPGRADE_STARTED);
+      enablePromoteButton = false;
 
       break;
 
     case kAutoupdateInstalled:
       {
         imageID = IDR_UPDATE_UPTODATE;
         string16 productName = l10n_util::GetStringUTF16(IDS_PRODUCT_NAME);
         if (version) {
           message = l10n_util::GetNSStringFWithFixup(
               IDS_UPGRADE_SUCCESSFUL,
               productName,
               base::SysNSStringToUTF16(version));
         } else {
           message = l10n_util::GetNSStringFWithFixup(
               IDS_UPGRADE_SUCCESSFUL_NOVERSION, productName);
         }
 
         // TODO(mark): Turn the button in the dialog into a restart button
         // instead of springing this sheet or dialog.
         NSWindow* window = [self window];
         NSWindow* restartDialogParent = [window isVisible] ? window : nil;
         restart_browser::RequestRestart(restartDialogParent);
       }
 
       break;
 
-    case kAutoupdateInstallFailed:
-      recentShownInstallFailedStatus = YES;
+    case kAutoupdatePromoting:
+#if 1
+      // TODO(mark): See the TODO in -adjustUpdateUIVisibility for an
+      // explanation of why nothing can be done here at the moment.  When
+      // KSRegistration handles promotion asynchronously, this dummy block can
+      // be replaced with the #else block.  For now, just leave the messaging
+      // alone.  http://b/2290009.
+      updateMessage = false;
+#else
+      // The visibility may be changing.
+      [self adjustUpdateUIVisibility];
 
-      // Allow another chance.
-      [updateNowButton_ setEnabled:YES];
+      // This is not a terminal state, and kAutoupdatePromoted or
+      // kAutoupdatePromoteFailed will follow.  Use the throbber and
+      // "checking" message so that it looks like something's happening.
+      throbber = true;
+      message = l10n_util::GetNSStringWithFixup(IDS_UPGRADE_CHECK_STARTED);
+#endif
 
-      // Fall through.
+      enablePromoteButton = false;
+
+      break;
+
+    case kAutoupdatePromoted:
+      // The visibility may be changing.
+      [self adjustUpdateUIVisibility];
+
+      if (![updateBlock_ isHidden]) {
+        // If promotion completes while the window is visible, go straight
+        // into an update check.  Return immediately, this routine will be
+        // re-entered shortly with kAutoupdateChecking.
+        [self checkForUpdate];
+        return;
+      }
+
+      // Nothing actually failed, but updates aren't possible.  The throbber
+      // and message are hidden, but they'll be reset to these dummy values
+      // just to get the throbber to stop spinning if it's running.
+      imageID = IDR_UPDATE_FAIL;
+      message = l10n_util::GetNSStringFWithFixup(IDS_UPGRADE_ERROR,
+                                                 IntToString16(status));
+
+      break;
+
+    case kAutoupdateRegisterFailed:
+      imageID = IDR_UPDATE_FAIL;
+      message = l10n_util::GetNSStringFWithFixup(IDS_UPGRADE_ERROR,
+                                                 IntToString16(status));
+      enablePromoteButton = false;
+
+      break;
 
     case kAutoupdateCheckFailed:
       imageID = IDR_UPDATE_FAIL;
       message = l10n_util::GetNSStringFWithFixup(IDS_UPGRADE_ERROR,
                                                  IntToString16(status));
+
+      break;
+
+    case kAutoupdateInstallFailed:
+      recentShownUserActionFailedStatus = YES;
+
+      imageID = IDR_UPDATE_FAIL;
+      message = l10n_util::GetNSStringFWithFixup(IDS_UPGRADE_ERROR,
+                                                 IntToString16(status));
+
+      // Allow another chance.
+      enableUpdateButton = true;
+
+      break;
+
+    case kAutoupdatePromoteFailed:
+      recentShownUserActionFailedStatus = YES;
+
+      imageID = IDR_UPDATE_FAIL;
+      message = l10n_util::GetNSStringFWithFixup(IDS_UPGRADE_ERROR,
+                                                 IntToString16(status));
 
       break;
 
     default:
       NOTREACHED();
+
       return;
   }
 
-  if (throbber) {
-    [self setUpdateThrobberMessage:message];
-  } else {
-    DCHECK_NE(imageID, 0);
-    [self setUpdateImage:imageID message:message];
+  if (updateMessage) {
+    if (throbber) {
+      [self setUpdateThrobberMessage:message];
+    } else {
+      DCHECK_NE(imageID, 0);
+      [self setUpdateImage:imageID message:message];
+    }
   }
+
+  // Note that these buttons may be hidden depending on what
+  // -adjustUpdateUIVisibility did.  Their enabled/disabled status doesn't
+  // necessarily have anything to do with their visibility.
+  [updateNowButton_ setEnabled:enableUpdateButton];
+  [promoteButton_ setEnabled:enablePromoteButton];
 }
 
 - (BOOL)textView:(NSTextView *)aTextView
    clickedOnLink:(id)link
          atIndex:(NSUInteger)charIndex {
   // We always create a new window, so there's no need to try to re-use
   // an existing one just to pass in the NEW_WINDOW disposition.
   Browser* browser = Browser::Create(profile_);
   if (browser) {
     browser->OpenURL(GURL([link UTF8String]), GURL(), NEW_WINDOW,
@@ skipping 127 matching lines @@
   NSRange string_range = NSMakeRange(0, [legal_block length]);
   [legal_block addAttribute:NSFontAttributeName
                       value:[NSFont labelFontOfSize:11]
                       range:string_range];
 
   [legal_block endEditing];
   return legal_block;
 }
 
 @end  // @implementation AboutWindowController