Make download items drag sources on OS X.

chrome/browser/cocoa/bookmark_button.mm

Index: chrome/browser/cocoa/bookmark_button.mm
diff --git a/chrome/browser/cocoa/bookmark_button.mm b/chrome/browser/cocoa/bookmark_button.mm
index 55c95f6dfe677f28ed045a3ce9574ad070493ae6..b0b6ecd9af15572e1864b576fead74c38d23171b 100644
--- a/chrome/browser/cocoa/bookmark_button.mm
+++ b/chrome/browser/cocoa/bookmark_button.mm
@@ -1,4 +1,4 @@
-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -6,19 +6,9 @@
 #import "base/scoped_nsobject.h"
 #import "chrome/browser/cocoa/bookmark_button.h"
 #import "chrome/browser/cocoa/bookmark_button_cell.h"
-#import "third_party/GTM/AppKit/GTMTheme.h"
-
-namespace {
-
-// Code taken from <http://codereview.chromium.org/180036/diff/3001/3004>.
-// TODO(viettrungluu): Do we want common, standard code for drag hysteresis?
-const CGFloat kWebDragStartHysteresisX = 5.0;
-const CGFloat kWebDragStartHysteresisY = 5.0;
 
 // The opacity of the bookmark button drag image.
-const CGFloat kDragImageOpacity = 0.7;
-
-}
+static const CGFloat kDragImageOpacity = 0.7;
 
 @interface BookmarkButton(Private)
 
@@ -29,25 +19,15 @@ const CGFloat kDragImageOpacity = 0.7;
 
 @implementation BookmarkButton
 
-@synthesize draggable = draggable_;
 @synthesize delegate = delegate_;
 
-- (id)initWithFrame:(NSRect)frame {
-  if ((self = [super initWithFrame:frame])) {
-    draggable_ = YES;
-  }
-  return self;
-}
-
 // By default, NSButton ignores middle-clicks.
 - (void)otherMouseUp:(NSEvent*)event {
   [self performClick:self];
 }
 
+// Overridden from DraggableButton.
 - (void)beginDrag:(NSEvent*)event {
-  // Starting drag. Never start another drag until another mouse down.
-  mayDragStart_ = NO;
-
   if (delegate_) {
     // Ask our delegate to fill the pasteboard for us.
     NSPasteboard* pboard = [NSPasteboard pasteboardWithName:NSDragPboard];
@@ -64,7 +44,7 @@ const CGFloat kDragImageOpacity = 0.7;
     [self dragImage:[self dragImage] at:NSMakePoint(0, yAt) offset:dragOffset
               event:event pasteboard:pboard source:self slideBack:YES];
 
-    // And we're done.
+    // And we're done.	
     [self autorelease];
   } else {
     // Avoid blowing up, but we really shouldn't get here.
@@ -75,8 +55,7 @@ const CGFloat kDragImageOpacity = 0.7;
 - (void)draggedImage:(NSImage*)anImage
              endedAt:(NSPoint)aPoint
            operation:(NSDragOperation)operation {
-  beingDragged_ = NO;
-  [[self cell] setHighlighted:NO];
+  [super endDrag];
 }
 
 - (NSDragOperation)draggingSourceOperationMaskForLocal:(BOOL)isLocal {
@@ -84,61 +63,6 @@ const CGFloat kDragImageOpacity = 0.7;
                  : NSDragOperationCopy;
 }
 
-- (void)mouseUp:(NSEvent*)theEvent {
-  // Make sure that we can't start a drag until we see a mouse down again.
-  mayDragStart_ = NO;
-
-  // This conditional is never true (DnD loops in Cocoa eat the mouse
-  // up) but I added it in case future versions of Cocoa do unexpected
-  // things.
-  if (beingDragged_) {
-    NOTREACHED();
-    return [super mouseUp:theEvent];
-  }
-
-  // There are non-drag cases where a mouseUp: may happen
-  // (e.g. mouse-down, cmd-tab to another application, move mouse,
-  // mouse-up).  So we check.
-  NSPoint viewLocal = [self convertPoint:[theEvent locationInWindow]
-                                fromView:[[self window] contentView]];
-  if (NSPointInRect(viewLocal, [self bounds])) {
-    [self performClick:self];
-  } else {
-    [[self cell] setHighlighted:NO];
-  }
-}
-
-// Mimic "begin a click" operation visually.  Do NOT follow through
-// with normal button event handling.
-- (void)mouseDown:(NSEvent*)theEvent {
-  mayDragStart_ = YES;
-  [[self cell] setHighlighted:YES];
-  initialMouseDownLocation_ = [theEvent locationInWindow];
-}
-
-// Return YES if we have crossed a threshold of movement after
-// mouse-down when we should begin a drag.  Else NO.
-- (BOOL)hasCrossedDragThreshold:(NSEvent*)theEvent {
-  NSPoint currentLocation = [theEvent locationInWindow];
-  if ((abs(currentLocation.x - initialMouseDownLocation_.x) >
-       kWebDragStartHysteresisX) ||
-      (abs(currentLocation.y - initialMouseDownLocation_.y) >
-       kWebDragStartHysteresisY)) {
-    return YES;
-  } else {
-    return NO;
-  }
-}
-
-- (void)mouseDragged:(NSEvent*)theEvent {
-  if (beingDragged_) {
-    [super mouseDragged:theEvent];
-  } else if (draggable_ && mayDragStart_ &&
-             [self hasCrossedDragThreshold:theEvent]) {
-    [self beginDrag:theEvent];
-  }
-}
-
 @end
 
 @implementation BookmarkButton(Private)