1 // Copyright 2019 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/layout/proposed_layout.h"
6
7 #include <map>
8 #include <sstream>
9 #include <string>
10
11 #include "ui/gfx/animation/tween.h"
12
13 namespace views {
14
15 namespace {
16
SizeBoundValueBetween(double value,const SizeBound & start,const SizeBound & target)17 SizeBound SizeBoundValueBetween(double value,
18 const SizeBound& start,
19 const SizeBound& target) {
20 return (start.is_bounded() && target.is_bounded())
21 ? gfx::Tween::IntValueBetween(value, start.value(), target.value())
22 : target;
23 }
24
SizeBoundsBetween(double value,const SizeBounds & start,const SizeBounds & target)25 SizeBounds SizeBoundsBetween(double value,
26 const SizeBounds& start,
27 const SizeBounds& target) {
28 return {SizeBoundValueBetween(value, start.width(), target.width()),
29 SizeBoundValueBetween(value, start.height(), target.height())};
30 }
31
32 } // anonymous namespace
33
operator ==(const ChildLayout & other) const34 bool ChildLayout::operator==(const ChildLayout& other) const {
35 // Note: if the view is not visible, the bounds do not matter as they will not
36 // be set.
37 return child_view == other.child_view && visible == other.visible &&
38 (!visible || bounds == other.bounds);
39 }
40
ToString() const41 std::string ChildLayout::ToString() const {
42 std::ostringstream oss;
43 oss << "{" << child_view << (visible ? " visible " : " not visible ")
44 << bounds.ToString() << " / " << available_size.ToString() << "}";
45 return oss.str();
46 }
47
48 ProposedLayout::ProposedLayout() = default;
49 ProposedLayout::ProposedLayout(const ProposedLayout& other) = default;
50 ProposedLayout::ProposedLayout(ProposedLayout&& other) = default;
ProposedLayout(const gfx::Size & size,const std::initializer_list<ChildLayout> & children)51 ProposedLayout::ProposedLayout(
52 const gfx::Size& size,
53 const std::initializer_list<ChildLayout>& children)
54 : host_size(size), child_layouts(children) {}
55 ProposedLayout::~ProposedLayout() = default;
56 ProposedLayout& ProposedLayout::operator=(const ProposedLayout& other) =
57 default;
58 ProposedLayout& ProposedLayout::operator=(ProposedLayout&& other) = default;
59
operator ==(const ProposedLayout & other) const60 bool ProposedLayout::operator==(const ProposedLayout& other) const {
61 return host_size == other.host_size && child_layouts == other.child_layouts;
62 }
63
ToString() const64 std::string ProposedLayout::ToString() const {
65 std::ostringstream oss;
66 oss << "{" << host_size.ToString() << " {";
67 bool first = true;
68 for (const auto& child_layout : child_layouts) {
69 if (first)
70 first = false;
71 else
72 oss << ", ";
73 oss << child_layout.ToString();
74 }
75 oss << "}}";
76 return oss.str();
77 }
78
ProposedLayoutBetween(double value,const ProposedLayout & start,const ProposedLayout & target)79 ProposedLayout ProposedLayoutBetween(double value,
80 const ProposedLayout& start,
81 const ProposedLayout& target) {
82 if (value >= 1.0)
83 return target;
84
85 ProposedLayout layout;
86
87 // Interpolate the host size.
88 layout.host_size =
89 gfx::Tween::SizeValueBetween(value, start.host_size, target.host_size);
90
91 // The views may not be listed in the same order and some views might be
92 // omitted from either the |start| or |target| layout.
93 std::map<const views::View*, size_t> start_view_to_index;
94 for (size_t i = 0; i < start.child_layouts.size(); ++i)
95 start_view_to_index.emplace(start.child_layouts[i].child_view, i);
96 for (const ChildLayout& target_child : target.child_layouts) {
97 // Try to match the view from the target with the view from the start.
98 const auto start_match = start_view_to_index.find(target_child.child_view);
99 if (start_match == start_view_to_index.end()) {
100 // If there is no match, make the view present but invisible.
101 layout.child_layouts.push_back({target_child.child_view, false});
102 } else {
103 // Tween the two layouts.
104 const ChildLayout& start_child = start.child_layouts[start_match->second];
105 layout.child_layouts.push_back(
106 {target_child.child_view, start_child.visible && target_child.visible,
107 gfx::Tween::RectValueBetween(value, start_child.bounds,
108 target_child.bounds),
109 SizeBoundsBetween(value, start_child.available_size,
110 target_child.available_size)});
111 }
112 }
113 return layout;
114 }
115
116 } // namespace views
117