Mac: Let status bubble dodge to the right if necessary.

chrome/browser/cocoa/status_bubble_mac.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.
 
 #include "chrome/browser/cocoa/status_bubble_mac.h"
 
 #include <limits>
 
 #include "app/gfx/text_elider.h"
 #include "base/compiler_specific.h"
@@ skipping 207 matching lines @@
 
   // Adjust the position to sit on top of download and extension shelves.
   // |delegate_| can be nil during unit tests.
   if ([delegate_ respondsToSelector:@selector(verticalOffsetForStatusBubble)])
     window_frame.origin.y += [delegate_ verticalOffsetForStatusBubble];
 
   // Get the cursor position relative to the popup.
   cursor_location.x -= NSMaxX(window_frame);
   cursor_location.y -= NSMaxY(window_frame);
 
+  bool isShelfVisible = [delegate_ verticalOffsetForStatusBubble] > 0;
+
   // If the mouse is in a position where we think it would move the
   // status bubble, figure out where and how the bubble should be moved.
   if (cursor_location.y < kMousePadding &&
       cursor_location.x < kMousePadding) {
     int offset = kMousePadding - cursor_location.y;
 
     // Make the movement non-linear.
     offset = offset * offset / kMousePadding;
 
     // When the mouse is entering from the right, we want the offset to be
     // scaled by how horizontally far away the cursor is from the bubble.
     if (cursor_location.x > 0) {
       offset = offset * ((kMousePadding - cursor_location.x) / kMousePadding);
     }
 
-    // Cap the offset and change the visual presentation of the bubble
-    // depending on where it ends up (so that rounded corners square off
-    // and mate to the edges of the tab content).
-    if (offset >= NSHeight(window_frame)) {
-      offset = NSHeight(window_frame);
-      [[window_ contentView] setCornerFlags:
-          kRoundedBottomLeftCorner | kRoundedBottomRightCorner];
-    } else if (offset > 0) {
-      [[window_ contentView] setCornerFlags:
-          kRoundedTopRightCorner | kRoundedBottomLeftCorner |
-          kRoundedBottomRightCorner];
-    } else {
-      [[window_ contentView] setCornerFlags:kRoundedTopRightCorner];
+    bool isOnScreen = true;
+    NSScreen* screen = [window_ screen];
+    if (screen &&
+        NSMinY([screen visibleFrame]) > NSMinY(window_frame) - offset) {
+      isOnScreen = false;
     }
 
-    window_frame.origin.y -= offset;
+    if (isOnScreen && !isShelfVisible) {
+      // Cap the offset and change the visual presentation of the bubble
+      // depending on where it ends up (so that rounded corners square off
+      // and mate to the edges of the tab content).
+      if (offset >= NSHeight(window_frame)) {
+        offset = NSHeight(window_frame);
+        [[window_ contentView] setCornerFlags:
+            kRoundedBottomLeftCorner | kRoundedBottomRightCorner];
+      } else if (offset > 0) {
+        [[window_ contentView] setCornerFlags:
+            kRoundedTopRightCorner | kRoundedBottomLeftCorner |
+            kRoundedBottomRightCorner];
+      } else {
+        [[window_ contentView] setCornerFlags:kRoundedTopRightCorner];
+      }
+      window_frame.origin.y -= offset;
+    } else {
+      // The bubble will obscure the download shelf.  Move the bubble to the
+      // right and reset Y offset_ to zero.
+      [[window_ contentView] setCornerFlags:kRoundedTopLeftCorner];
+
+      // Subtract border width + bubble width.
+      window_frame.origin.x += NSWidth([parent_ frame]) - NSWidth(window_frame);
+    }
   } else {
     [[window_ contentView] setCornerFlags:kRoundedTopRightCorner];
   }
 
   [window_ setFrame:window_frame display:YES];
 }
 
 void StatusBubbleMac::UpdateDownloadShelfVisibility(bool visible) {
 }
 
@@ skipping 216 matching lines @@
 }
 
 NSRect StatusBubbleMac::CalculateWindowFrame() {
   DCHECK(parent_);
 
   NSRect rect = [parent_ frame];
   rect.size.height = kWindowHeight;
   rect.size.width = static_cast<int>(kWindowWidthPercent * rect.size.width);
   return rect;
 }