Vertical scrolling arrows in bookmark bar folder windows when needed....

chrome/browser/cocoa/bookmark_bar_folder_controller_unittest.mm

 // Copyright (c) 2010 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 <Cocoa/Cocoa.h>
 
 #include "base/basictypes.h"
 #include "base/scoped_nsobject.h"
 #import "chrome/browser/cocoa/bookmark_bar_constants.h"  // namespace bookmarks
 #import "chrome/browser/cocoa/bookmark_bar_controller.h"
@@ skipping 63 matching lines @@
 }
 
 // We don't have a real BookmarkBarController as our parent root so
 // we fake this one out.
 - (void)closeAllBookmarkFolders {
   [self closeBookmarkFolder:self];
 }
 
 @end
 
+namespace {
+const int kLotsOfNodesCount = 150;
+};
+
 class BookmarkBarFolderControllerTest : public CocoaTest {
  public:
   BrowserTestHelper helper_;
   scoped_nsobject<BookmarkBarController> parentBarController_;
   const BookmarkNode* folderA_;  // owned by model
   const BookmarkNode* longTitleNode_;  // owned by model
 
   BookmarkBarFolderControllerTest() {
     BookmarkModel* model = helper_.profile()->GetBookmarkModel();
     const BookmarkNode* parent = model->GetBookmarkBarNode();
@@ skipping 29 matching lines @@
   }
 
   // Remove the bookmark with the long title.
   void RemoveLongTitleNode() {
     BookmarkModel* model = helper_.profile()->GetBookmarkModel();
     model->Remove(longTitleNode_->GetParent(),
                   longTitleNode_->GetParent()->IndexOfChild(longTitleNode_));
   }
 
   // Add LOTS of nodes to our model if needed (e.g. scrolling).
-  void AddLotsOfNodes() {
+  // Returns the number of nodes added.
+  int AddLotsOfNodes() {
     BookmarkModel* model = helper_.profile()->GetBookmarkModel();
-    for (int i = 0; i < 150; i++) {
+    for (int i = 0; i < kLotsOfNodesCount; i++) {
       model->AddURL(folderA_, folderA_->GetChildCount(), L"repeated title",
                     GURL("http://www.google.com/repeated/url"));
     }
+    return kLotsOfNodesCount;
   }
 
 
   // Return a simple BookmarkBarFolderController.
   BookmarkBarFolderController* SimpleBookmarkBarFolderController() {
     BookmarkButton* parentButton = [[parentBarController_ buttons]
                                      objectAtIndex:0];
     BookmarkBarFolderController* c =
       [[BookmarkBarFolderControllerPong alloc]
                initWithParentButton:parentButton
                    parentController:nil
                       barController:parentBarController_];
     [c window];  // Force nib load.
     return c;
   }
-
 };
 
 TEST_F(BookmarkBarFolderControllerTest, InitCreateAndDelete) {
   scoped_nsobject<BookmarkBarFolderController> bbfc;
   bbfc.reset(SimpleBookmarkBarFolderController());
 
   // Make sure none of the buttons overlap, that all are inside
   // the content frame, and their cells are of the proper class.
   NSArray* buttons = [bbfc buttons];
   EXPECT_TRUE([buttons count]);
@@ skipping 156 matching lines @@
   CGFloat thinWidth = NSWidth([[bbfc window] frame]);
 
   // Make sure window size changed as expected.
   EXPECT_GT(wideWidth, thinWidth);
 }
 
 // Simple scrolling tests.
 TEST_F(BookmarkBarFolderControllerTest, SimpleScroll) {
   scoped_nsobject<BookmarkBarFolderController> bbfc;
 
-  AddLotsOfNodes();
+  int nodecount = AddLotsOfNodes();
   bbfc.reset(SimpleBookmarkBarFolderController());
   EXPECT_TRUE(bbfc.get());
   [bbfc showWindow:bbfc.get()];
 
   // Make sure the window fits on the screen.
   EXPECT_LT(NSHeight([[bbfc window] frame]),
             NSHeight([[NSScreen mainScreen] frame]));
 
+  // Verify the logic used by the scroll arrow code.
+  EXPECT_TRUE([bbfc canScrollUp]);
+  EXPECT_FALSE([bbfc canScrollDown]);
+
   // Scroll it up.  Make sure the window has gotten bigger each time.
   // Also, for each scroll, make sure our hit test finds a new button
   // (to confirm the content area changed).
   NSView* savedHit = nil;
   for (int i=0; i<3; i++) {
     CGFloat height = NSHeight([[bbfc window] frame]);
     [bbfc performOneScroll:60];
     EXPECT_GT(NSHeight([[bbfc window] frame]), height);
-    NSView* hit = [[[bbfc window] contentView] hitTest:NSMakePoint(10, 10)];
+    NSView* hit = [[[bbfc window] contentView] hitTest:NSMakePoint(22, 22)];
     EXPECT_NE(hit, savedHit);
     savedHit = hit;
   }
 
   // Keep scrolling up; make sure we never get bigger than the screen.
   // Also confirm we never scroll the window off the screen.
+  bool bothAtOnce = false;
   NSRect screenFrame = [[NSScreen mainScreen] frame];
-  for (int i=0; i<100; i++) {
+  for (int i = 0; i < nodecount; i++) {
     [bbfc performOneScroll:60];
     EXPECT_TRUE(NSContainsRect(screenFrame,
                                [[bbfc window] frame]));
+    // Make sure, sometime during our scroll, we have the ability to
+    // scroll in either direction.
+    if ([bbfc canScrollUp] &&
+        [bbfc canScrollDown])
+      bothAtOnce = true;
   }
+  EXPECT_TRUE(bothAtOnce);
+
+  // Once we've scrolled to the end, our only option should be to scroll back.
+  EXPECT_FALSE([bbfc canScrollUp]);
+  EXPECT_TRUE([bbfc canScrollDown]);
 
   // Now scroll down and make sure the window size does not change.
   // Also confirm we never scroll the window off the screen the other
   // way.
-  for (int i=0; i<200; i++) {
+  for (int i=0; i<nodecount+50; i++) {
     CGFloat height = NSHeight([[bbfc window] frame]);
     [bbfc performOneScroll:-60];
     EXPECT_EQ(height, NSHeight([[bbfc window] frame]));
     EXPECT_TRUE(NSContainsRect(screenFrame,
                                [[bbfc window] frame]));
   }
 }
 
 class BookmarkBarFolderControllerDragDropTest : public CocoaTest {
  public:
@@ skipping 561 matching lines @@
   [folder deleteBookmark:folder];
   EXPECT_FALSE([folder folderController]);
 }
 
 // TODO(jrg): draggingEntered: and draggingExited: trigger timers so
 // they are hard to test.  Factor out "fire timers" into routines
 // which can be overridden to fire immediately to make behavior
 // confirmable.
 // There is a similar problem with mouseEnteredButton: and
 // mouseExitedButton:.