Mac: implement drag-and-drop of URLs to tabs/tab strip.

chrome/browser/cocoa/url_drop_target.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/url_drop_target.h"
+
+#include "base/logging.h"
+#import "third_party/mozilla/include/NSPasteboard+Utils.h"
+
+@interface URLDropTargetHandler(Private)
+
+// Get the window controller.
+- (id<URLDropTargetWindowController>)windowController;
+
+// Gets the appropriate drag operation given the |NSDraggingInfo|.
+- (NSDragOperation)getDragOperation:(id<NSDraggingInfo>)sender;
+
+// Tell the window controller to hide the drop indicator.
+- (void)hideIndicator;
+
+@end  // @interface URLDropTargetHandler(Private)
+
+@implementation URLDropTargetHandler
+
+- (id)initWithView:(NSView*)view {
+  if ((self = [super init])) {
+    view_ = view;
+    [view_ registerForDraggedTypes:
+         [NSArray arrayWithObjects:kWebURLsWithTitlesPboardType,
+                                   NSURLPboardType,
+                                   NSStringPboardType,
+                                   NSFilenamesPboardType,
+                                   nil]];
+  }
+  return self;
+}
+
+// The following four methods implement parts of the |NSDraggingDestination|
+// protocol, which the owner should "forward" to its |URLDropTargetHandler|
+// (us).
+
+- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender {
+  return [self getDragOperation:sender];
+}
+
+- (NSDragOperation)draggingUpdated:(id<NSDraggingInfo>)sender {
+  NSDragOperation dragOp = [self getDragOperation:sender];
+  if (dragOp == NSDragOperationCopy) {
+    // Just tell the window controller to update the indicator.
+    [[self windowController] indicateDropURLsAt:[sender draggingLocation]];
+  }
+  return dragOp;
+}
+
+- (void)draggingExited:(id<NSDraggingInfo>)sender {
+  [self hideIndicator];
+}
+
+- (BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
+  [self hideIndicator];
+
+  NSPasteboard* pboard = [sender draggingPasteboard];
+  if ([pboard containsURLData]) {
+    NSArray* urls = nil;
+    NSArray* titles;  // discarded
+    [pboard getURLs:&urls andTitles:&titles];
+
+    if ([urls count]) {
+      // Tell the window controller about the dropped URL(s).
+      [[self windowController] dropURLs:urls at:[sender draggingLocation]];
+      return YES;
+    }
+  }
+
+  return NO;
+}
+
+@end  // @implementation URLDropTargetHandler
+
+@implementation URLDropTargetHandler(Private)
+
+- (id<URLDropTargetWindowController>)windowController {
+  id<URLDropTargetWindowController> controller =
+      [[view_ window] windowController];
+  DCHECK([(id)controller conformsToProtocol:
+      @protocol(URLDropTargetWindowController)]);
+  return controller;
+}
+
+- (NSDragOperation)getDragOperation:(id<NSDraggingInfo>)sender {
+  // Only allow the copy operation.
+  return [sender draggingSourceOperationMask] & NSDragOperationCopy;
+}
+
+- (void)hideIndicator {
+  [[self windowController] hideDropURLsIndicator];
+}
+
+@end  // @implementation URLDropTargetHandler(Private)