1 // Copyright (c) 2012 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 #include "ui/views/widget/drop_helper.h"
6
7 #include "ui/base/dragdrop/drag_drop_types.h"
8 #include "ui/views/view.h"
9 #include "ui/views/widget/widget.h"
10
11 namespace views {
12
DropHelper(View * root_view)13 DropHelper::DropHelper(View* root_view)
14 : root_view_(root_view),
15 target_view_(NULL),
16 deepest_view_(NULL) {
17 }
18
~DropHelper()19 DropHelper::~DropHelper() {
20 }
21
ResetTargetViewIfEquals(View * view)22 void DropHelper::ResetTargetViewIfEquals(View* view) {
23 if (target_view_ == view)
24 target_view_ = NULL;
25 if (deepest_view_ == view)
26 deepest_view_ = NULL;
27 }
28
OnDragOver(const OSExchangeData & data,const gfx::Point & root_view_location,int drag_operation)29 int DropHelper::OnDragOver(const OSExchangeData& data,
30 const gfx::Point& root_view_location,
31 int drag_operation) {
32 View* view = CalculateTargetViewImpl(root_view_location, data, true,
33 &deepest_view_);
34
35 if (view != target_view_) {
36 // Target changed notify old drag exited, then new drag entered.
37 NotifyDragExit();
38 target_view_ = view;
39 NotifyDragEntered(data, root_view_location, drag_operation);
40 }
41
42 return NotifyDragOver(data, root_view_location, drag_operation);
43 }
44
OnDragExit()45 void DropHelper::OnDragExit() {
46 NotifyDragExit();
47 deepest_view_ = target_view_ = NULL;
48 }
49
OnDrop(const OSExchangeData & data,const gfx::Point & root_view_location,int drag_operation)50 int DropHelper::OnDrop(const OSExchangeData& data,
51 const gfx::Point& root_view_location,
52 int drag_operation) {
53 View* drop_view = target_view_;
54 deepest_view_ = target_view_ = NULL;
55 if (!drop_view)
56 return ui::DragDropTypes::DRAG_NONE;
57
58 if (drag_operation == ui::DragDropTypes::DRAG_NONE) {
59 drop_view->OnDragExited();
60 return ui::DragDropTypes::DRAG_NONE;
61 }
62
63 gfx::Point view_location(root_view_location);
64 View* root_view = drop_view->GetWidget()->GetRootView();
65 View::ConvertPointToTarget(root_view, drop_view, &view_location);
66 ui::DropTargetEvent drop_event(data, view_location, view_location,
67 drag_operation);
68 return drop_view->OnPerformDrop(drop_event);
69 }
70
CalculateTargetView(const gfx::Point & root_view_location,const OSExchangeData & data,bool check_can_drop)71 View* DropHelper::CalculateTargetView(
72 const gfx::Point& root_view_location,
73 const OSExchangeData& data,
74 bool check_can_drop) {
75 return CalculateTargetViewImpl(root_view_location, data, check_can_drop,
76 NULL);
77 }
78
CalculateTargetViewImpl(const gfx::Point & root_view_location,const OSExchangeData & data,bool check_can_drop,View ** deepest_view)79 View* DropHelper::CalculateTargetViewImpl(
80 const gfx::Point& root_view_location,
81 const OSExchangeData& data,
82 bool check_can_drop,
83 View** deepest_view) {
84 View* view = root_view_->GetEventHandlerForPoint(root_view_location);
85 if (view == deepest_view_) {
86 // The view the mouse is over hasn't changed; reuse the target.
87 return target_view_;
88 }
89 if (deepest_view)
90 *deepest_view = view;
91 // TODO(sky): for the time being these are separate. Once I port chrome menu
92 // I can switch to the #else implementation and nuke the OS_WIN
93 // implementation.
94 #if defined(OS_WIN)
95 // View under mouse changed, which means a new view may want the drop.
96 // Walk the tree, stopping at target_view_ as we know it'll accept the
97 // drop.
98 while (view && view != target_view_ &&
99 (!view->enabled() || !view->CanDrop(data))) {
100 view = view->parent();
101 }
102 #else
103 int formats = 0;
104 std::set<OSExchangeData::CustomFormat> custom_formats;
105 while (view && view != target_view_) {
106 if (view->enabled() &&
107 view->GetDropFormats(&formats, &custom_formats) &&
108 data.HasAnyFormat(formats, custom_formats) &&
109 (!check_can_drop || view->CanDrop(data))) {
110 // Found the view.
111 return view;
112 }
113 formats = 0;
114 custom_formats.clear();
115 view = view->parent();
116 }
117 #endif
118 return view;
119 }
120
NotifyDragEntered(const OSExchangeData & data,const gfx::Point & root_view_location,int drag_operation)121 void DropHelper::NotifyDragEntered(const OSExchangeData& data,
122 const gfx::Point& root_view_location,
123 int drag_operation) {
124 if (!target_view_)
125 return;
126
127 gfx::Point target_view_location(root_view_location);
128 View::ConvertPointToTarget(root_view_, target_view_, &target_view_location);
129 ui::DropTargetEvent enter_event(data,
130 target_view_location,
131 target_view_location,
132 drag_operation);
133 target_view_->OnDragEntered(enter_event);
134 }
135
NotifyDragOver(const OSExchangeData & data,const gfx::Point & root_view_location,int drag_operation)136 int DropHelper::NotifyDragOver(const OSExchangeData& data,
137 const gfx::Point& root_view_location,
138 int drag_operation) {
139 if (!target_view_)
140 return ui::DragDropTypes::DRAG_NONE;
141
142 gfx::Point target_view_location(root_view_location);
143 View::ConvertPointToTarget(root_view_, target_view_, &target_view_location);
144 ui::DropTargetEvent enter_event(data,
145 target_view_location,
146 target_view_location,
147 drag_operation);
148 return target_view_->OnDragUpdated(enter_event);
149 }
150
NotifyDragExit()151 void DropHelper::NotifyDragExit() {
152 if (target_view_)
153 target_view_->OnDragExited();
154 }
155
156 } // namespace views
157