1// Copyright 2013 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#import "ui/app_list/cocoa/apps_collection_view_drag_manager.h"
6
7#include "base/logging.h"
8#include "base/mac/foundation_util.h"
9#import "ui/app_list/cocoa/apps_grid_controller.h"
10#import "ui/app_list/cocoa/apps_grid_view_item.h"
11#import "ui/app_list/cocoa/item_drag_controller.h"
12
13namespace {
14
15// Distance cursor must travel in either x or y direction to start a drag.
16const CGFloat kDragThreshold = 5;
17
18}  // namespace
19
20@interface AppsCollectionViewDragManager ()
21
22// Returns the item index that |theEvent| would hit in the page at |pageIndex|
23// or NSNotFound if no item is hit.
24- (size_t)itemIndexForPage:(size_t)pageIndex
25              hitWithEvent:(NSEvent*)theEvent;
26
27- (void)initiateDrag:(NSEvent*)theEvent;
28- (void)updateDrag:(NSEvent*)theEvent;
29- (void)completeDrag;
30
31- (NSMenu*)menuForEvent:(NSEvent*)theEvent
32                 inPage:(NSCollectionView*)page;
33
34@end
35
36// An NSCollectionView that forwards mouse events to the factory they share.
37@interface GridCollectionView : NSCollectionView {
38 @private
39  AppsCollectionViewDragManager* factory_;
40}
41
42@property(assign, nonatomic) AppsCollectionViewDragManager* factory;
43
44@end
45
46@implementation AppsCollectionViewDragManager
47
48- (id)initWithCellSize:(NSSize)cellSize
49                  rows:(size_t)rows
50               columns:(size_t)columns
51        gridController:(AppsGridController*)gridController {
52  if ((self = [super init])) {
53    cellSize_ = cellSize;
54    rows_ = rows;
55    columns_ = columns;
56    gridController_ = gridController;
57  }
58  return self;
59}
60
61- (NSCollectionView*)makePageWithFrame:(NSRect)pageFrame {
62  base::scoped_nsobject<GridCollectionView> itemCollectionView(
63      [[GridCollectionView alloc] initWithFrame:pageFrame]);
64  [itemCollectionView setFactory:self];
65  [itemCollectionView setMaxNumberOfRows:rows_];
66  [itemCollectionView setMinItemSize:cellSize_];
67  [itemCollectionView setMaxItemSize:cellSize_];
68  [itemCollectionView setSelectable:YES];
69  [itemCollectionView setFocusRingType:NSFocusRingTypeNone];
70  [itemCollectionView setBackgroundColors:
71      [NSArray arrayWithObject:[NSColor clearColor]]];
72  [itemCollectionView setDelegate:gridController_];
73
74  base::scoped_nsobject<AppsGridViewItem> itemPrototype(
75      [[AppsGridViewItem alloc] initWithSize:cellSize_]);
76  [[itemPrototype button] setTarget:gridController_];
77  [[itemPrototype button] setAction:@selector(onItemClicked:)];
78
79  [itemCollectionView setItemPrototype:itemPrototype];
80  return itemCollectionView.autorelease();
81}
82
83- (void)onMouseDownInPage:(NSCollectionView*)page
84                withEvent:(NSEvent*)theEvent {
85  size_t pageIndex = [gridController_ pageIndexForCollectionView:page];
86  itemHitIndex_ = [self itemIndexForPage:pageIndex
87                            hitWithEvent:theEvent];
88  if (itemHitIndex_ == NSNotFound)
89    return;
90
91  mouseDownLocation_ = [theEvent locationInWindow];
92  [[[gridController_ itemAtIndex:itemHitIndex_] view] mouseDown:theEvent];
93}
94
95- (void)onMouseDragged:(NSEvent*)theEvent {
96  if (itemHitIndex_ == NSNotFound)
97    return;
98
99  if (dragging_) {
100    [self updateDrag:theEvent];
101    return;
102  }
103
104  NSPoint mouseLocation = [theEvent locationInWindow];
105  CGFloat deltaX = mouseLocation.x - mouseDownLocation_.x;
106  CGFloat deltaY = mouseLocation.y - mouseDownLocation_.y;
107  if (deltaX * deltaX + deltaY * deltaY > kDragThreshold * kDragThreshold) {
108    [self initiateDrag:theEvent];
109    return;
110  }
111
112  [[[gridController_ itemAtIndex:itemHitIndex_] view] mouseDragged:theEvent];
113}
114
115- (void)onMouseUp:(NSEvent*)theEvent {
116  if (itemHitIndex_ == NSNotFound)
117    return;
118
119  if (dragging_) {
120    [self completeDrag];
121    return;
122  }
123
124  [[[gridController_ itemAtIndex:itemHitIndex_] view] mouseUp:theEvent];
125}
126
127- (size_t)itemIndexForPage:(size_t)pageIndex
128              hitWithEvent:(NSEvent*)theEvent {
129  NSCollectionView* page =
130      [gridController_ collectionViewAtPageIndex:pageIndex];
131  NSPoint pointInView = [page convertPoint:[theEvent locationInWindow]
132                                  fromView:nil];
133
134  const size_t itemsInPage = [[page content] count];
135  for (size_t indexInPage = 0; indexInPage < itemsInPage; ++indexInPage) {
136    if ([page mouse:pointInView
137             inRect:[page frameForItemAtIndex:indexInPage]]) {
138      return indexInPage + pageIndex * rows_ * columns_;
139    }
140  }
141
142  return NSNotFound;
143}
144
145- (void)initiateDrag:(NSEvent*)theEvent {
146  DCHECK_LT(itemHitIndex_, [gridController_ itemCount]);
147  dragging_ = YES;
148
149  if (!itemDragController_) {
150    itemDragController_.reset(
151        [[ItemDragController alloc] initWithGridCellSize:cellSize_]);
152    [[[gridController_ view] superview] addSubview:[itemDragController_ view]];
153  }
154
155  [itemDragController_ initiate:[gridController_ itemAtIndex:itemHitIndex_]
156              mouseDownLocation:mouseDownLocation_
157                currentLocation:[theEvent locationInWindow]
158                      timestamp:[theEvent timestamp]];
159
160  itemDragIndex_ = itemHitIndex_;
161  [self updateDrag:theEvent];
162}
163
164- (void)updateDrag:(NSEvent*)theEvent {
165  [itemDragController_ update:[theEvent locationInWindow]
166                    timestamp:[theEvent timestamp]];
167  [gridController_ maybeChangePageForPoint:[theEvent locationInWindow]];
168
169  size_t visiblePage = [gridController_ visiblePage];
170  size_t itemIndexOver = [self itemIndexForPage:visiblePage
171                                   hitWithEvent:theEvent];
172  DCHECK_NE(0u, [gridController_ itemCount]);
173  if (itemIndexOver == NSNotFound) {
174    if (visiblePage != [gridController_ pageCount] - 1)
175      return;
176
177    // If nothing was hit, but the last page is shown, move to the end.
178    itemIndexOver = [gridController_ itemCount] - 1;
179  }
180
181  if (itemDragIndex_ == itemIndexOver)
182    return;
183
184  [gridController_ moveItemInView:itemDragIndex_
185                      toItemIndex:itemIndexOver];
186  // A new item may be created when moving between pages. Ensure it is hidden.
187  [[[gridController_ itemAtIndex:itemIndexOver] button] setHidden:YES];
188  itemDragIndex_ = itemIndexOver;
189}
190
191- (void)cancelDrag {
192  if (!dragging_)
193    return;
194
195  [gridController_ moveItemInView:itemDragIndex_
196                      toItemIndex:itemHitIndex_];
197  itemDragIndex_ = itemHitIndex_;
198  [self completeDrag];
199  itemHitIndex_ = NSNotFound;  // Ignore future mouse events for this drag.
200}
201
202- (void)completeDrag {
203  DCHECK_GE(itemDragIndex_, 0u);
204  [gridController_ cancelScrollTimer];
205  AppsGridViewItem* item = [gridController_ itemAtIndex:itemDragIndex_];
206
207  // The item could still be animating in the NSCollectionView, so ask it where
208  // it would place the item.
209  NSCollectionView* pageView = base::mac::ObjCCastStrict<NSCollectionView>(
210      [[item view] superview]);
211  size_t indexInPage = itemDragIndex_ % (rows_ * columns_);
212  NSPoint targetOrigin = [[[itemDragController_ view] superview]
213      convertPoint:[pageView frameForItemAtIndex:indexInPage].origin
214          fromView:pageView];
215
216  [itemDragController_ complete:item
217                   targetOrigin:targetOrigin];
218  [gridController_ moveItemWithIndex:itemHitIndex_
219                        toModelIndex:itemDragIndex_];
220
221  dragging_ = NO;
222}
223
224- (NSMenu*)menuForEvent:(NSEvent*)theEvent
225                 inPage:(NSCollectionView*)page {
226  size_t pageIndex = [gridController_ pageIndexForCollectionView:page];
227  size_t itemIndex = [self itemIndexForPage:pageIndex
228                               hitWithEvent:theEvent];
229  if (itemIndex == NSNotFound)
230    return nil;
231
232  return [[gridController_ itemAtIndex:itemIndex] contextMenu];
233}
234
235@end
236
237@implementation GridCollectionView
238
239@synthesize factory = factory_;
240
241- (NSMenu*)menuForEvent:(NSEvent*)theEvent {
242  return [factory_ menuForEvent:theEvent
243                         inPage:self];
244}
245
246- (void)mouseDown:(NSEvent*)theEvent {
247  [factory_ onMouseDownInPage:self
248                    withEvent:theEvent];
249}
250
251- (void)mouseDragged:(NSEvent*)theEvent {
252  [factory_ onMouseDragged:theEvent];
253}
254
255- (void)mouseUp:(NSEvent*)theEvent {
256  [factory_ onMouseUp:theEvent];
257}
258
259- (BOOL)acceptsFirstResponder {
260  return NO;
261}
262
263@end
264