[mac] Implement dragging of multiple tabs.

chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.mm

 // Copyright (c) 2012 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/ui/cocoa/tabs/tab_strip_drag_controller.h"
 
 #import "base/mac/mac_util.h"
 #include "base/mac/scoped_cftyperef.h"
 #import "base/mac/sdk_forward_declarations.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_controller.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_controller_target.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_view.h"
 #import "chrome/browser/ui/cocoa/tabs/tab_window_controller.h"
+#import "chrome/browser/ui/cocoa/tabs/tab_strip_controller.h"
 
 const CGFloat kTearDistance = 36.0;
 const NSTimeInterval kTearDuration = 0.333;
 
 @interface TabStripDragController (Private)
 - (void)resetDragControllers;
 - (NSArray*)dropTargetsForController:(TabWindowController*)dragController;
 - (void)setWindowBackgroundVisibility:(BOOL)shouldBeVisible;
 - (void)endDrag:(NSEvent*)event;
 - (void)continueDrag:(NSEvent*)event;
@@ skipping 201 matching lines @@
   // Create or identify the dragged controller.
   if (!draggedController_) {
     // Get rid of any placeholder remaining in the original source window.
     [sourceController_ removePlaceholder];
 
     // Detach from the current window and put it in a new window. If there are
     // no more tabs remaining after detaching, the source window is about to
     // go away (it's been autoreleased) so we need to ensure we don't reference
     // it any more. In that case the new controller becomes our source
     // controller.
+    NSArray* tabs = [draggedTab_ selected] ? [tabStrip_ selectedViews]
+                                           : @[ [draggedTab_ tabView] ];
     draggedController_ =
-        [sourceController_ detachTabToNewWindow:[draggedTab_ tabView]];
+        [sourceController_ detachTabsToNewWindow:tabs
+                                      draggedTab:[draggedTab_ tabView]];
+
     dragWindow_ = [draggedController_ window];
     [dragWindow_ setAlphaValue:0.0];
     if (![sourceController_ hasLiveTabs]) {
       sourceController_ = draggedController_;
       sourceWindow_ = dragWindow_;
     }
 
     // Disable window animation before calling |orderFront:| when detaching
     // to a new window.
     NSWindowAnimationBehavior savedAnimationBehavior =
@@ skipping 76 matching lines @@
 
   // If we're not hovering over any window, make the window fully
   // opaque. Otherwise, find where the tab might be dropped and insert
   // a placeholder so it appears like it's part of that window.
   if (targetController_) {
     if (![[targetController_ window] isKeyWindow])
       [[targetController_ window] orderFront:nil];
 
     // Compute where placeholder should go and insert it into the
     // destination tab strip.
-    TabView* draggedTabView = (TabView*)[draggedController_ activeTabView];
-    NSRect tabFrame = [draggedTabView frame];
+    // The placeholder frame is the rect that contains all dragged tabs.
+    NSRect tabFrame = NSZeroRect;
+    for (NSView* tabView in [draggedController_ tabViews]) {
+      tabFrame = NSUnionRect(tabFrame, [tabView frame]);
+    }
     tabFrame.origin = [dragWindow_ convertBaseToScreen:tabFrame.origin];
     tabFrame.origin = [[targetController_ window]
                         convertScreenToBase:tabFrame.origin];
     tabFrame = [[targetController_ tabStripView]
                 convertRect:tabFrame fromView:nil];
     [targetController_ insertPlaceholderForTab:[draggedTab_ tabView]
                                          frame:tabFrame];
     [targetController_ layoutTabs];
   } else {
     [dragWindow_ makeKeyAndOrderFront:nil];
@@ skipping 27 matching lines @@
   // dragging. It will show when the next call to -layoutTabs (which happens
   // indirectly by several of the calls below, such as removing the
   // placeholder).
   [draggedController_ showNewTabButton:YES];
 
   if (draggingWithinTabStrip_) {
     if (tabWasDragged_) {
       // Move tab to new location.
       DCHECK([sourceController_ numberOfTabs]);
       TabWindowController* dropController = sourceController_;
-      [dropController moveTabView:[dropController activeTabView]
-                   fromController:nil];
+      [dropController moveTabViews:@[ [dropController activeTabView] ]
+                    fromController:nil];
     }
   } else if (targetController_) {
     // Move between windows. If |targetController_| is nil, we're not dropping
     // into any existing window.
-    NSView* draggedTabView = [draggedController_ activeTabView];
-    [targetController_ moveTabView:draggedTabView
-                    fromController:draggedController_];
+    [targetController_ moveTabViews:[draggedController_ tabViews]
+                     fromController:draggedController_];
     // Force redraw to avoid flashes of old content before returning to event
     // loop.
     [[targetController_ window] display];
     [targetController_ showWindow:nil];
     [draggedController_ removeOverlay];
   } else {
     // Only move the window around on screen. Make sure it's set back to
     // normal state (fully opaque, has shadow, has key, etc).
     [draggedController_ removeOverlay];
     // Don't want to re-show the window if it was closed during the drag.
@@ skipping 68 matching lines @@
     [[targetController_ window] makeMainWindow];
   } else {
     [dragWindow_ setAlphaValue:0.5];
     [[draggedController_ overlayWindow] setHasShadow:NO];
     [[draggedController_ window] makeMainWindow];
   }
   chromeIsVisible_ = shouldBeVisible;
 }
 
 @end