blob: a72defc61979d8beebd933506b04464a07526610 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
// Copyright (c) 2010 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.
#ifndef CHROME_BROWSER_TAB_CONTENTS_LOADER_MANAGER_H_
#define CHROME_BROWSER_TAB_CONTENTS_LOADER_MANAGER_H_
#pragma once
#include <map>
#include "base/scoped_ptr.h"
#include "chrome/browser/search_engines/template_url_id.h"
class MatchPreviewLoader;
class MatchPreviewLoaderDelegate;
// LoaderManager is responsible for maintaining the MatchPreviewLoaders for
// MatchPreview. LoaderManager keeps track of one loader for loading non-instant
// urls, and a loader per TemplateURLID for loading instant urls. A loader per
// TemplateURLID is necessitated due to not knowing in advance if a site
// really supports instant (for example, the user might have opted out even
// though it's supported).
//
// Users of LoaderManager need only concern themselves with the current and
// pending loaders. The current loader is the loader that if ready is shown by
// MatchPreview. The pending loader is used if the current loader is ready and
// update is invoked with a different id. In this case the current loader is
// left as current (and it's preview contents stopped) and the newly created
// loader is set to pending. Once the pending loader is ready
// MakePendingCurrent should be invoked to make the pending the current loader.
//
// MatchPreviewLoader owns all the MatchPreviewLoaders returned. You can take
// ownership of the current loader by invoking ReleaseCurrentLoader.
class LoaderManager {
public:
explicit LoaderManager(MatchPreviewLoaderDelegate* loader_delegate);
~LoaderManager();
// Updates the current loader. If the current loader is replaced and should be
// deleted it is set in |old_loader|. This is done to allow the caller to
// notify delegates before the old loader is destroyed. This returns the
// active MatchPreviewLoader that should be used.
MatchPreviewLoader* UpdateLoader(TemplateURLID instant_id,
scoped_ptr<MatchPreviewLoader>* old_loader);
// Makes the pending loader the current loader. If ownership of the old
// loader is to pass to the caller |old_loader| is set appropriately.
void MakePendingCurrent(scoped_ptr<MatchPreviewLoader>* old_loader);
// Returns the current loader and clears internal references to it. This
// should be used prior to destroying the LoaderManager when the owner of
// LoaderManager wants to take ownership of the loader.
MatchPreviewLoader* ReleaseCurrentLoader();
// Returns the current loader, may be null.
MatchPreviewLoader* current_loader() const { return current_loader_; }
// Returns the pending loader, may be null.
MatchPreviewLoader* pending_loader() const { return pending_loader_; }
// The active loader is the loader that should be used for new loads. It is
// either the pending loader or the current loader.
MatchPreviewLoader* active_loader() const {
return pending_loader_ ? pending_loader_ : current_loader_;
}
// Returns the number of instant loaders.
// This is exposed for tests.
size_t num_instant_loaders() const { return instant_loaders_.size(); }
private:
typedef std::map<TemplateURLID, MatchPreviewLoader*> Loaders;
// Creates a loader and if |id| is non-zero registers it in instant_loaders_.
MatchPreviewLoader* CreateLoader(TemplateURLID id);
// Returns the loader for loading instant results with the specified id. If
// there is no loader for the specified id a new one is created.
MatchPreviewLoader* GetInstantLoader(TemplateURLID id);
MatchPreviewLoaderDelegate* loader_delegate_;
// The current loader.
MatchPreviewLoader* current_loader_;
// Loader we want to use as soon as ready. This is only non-null if
// current_loader_ is ready and Update is invoked with a different template
// url id.
MatchPreviewLoader* pending_loader_;
// Maps for template url id to loader used for that template url id.
Loaders instant_loaders_;
DISALLOW_COPY_AND_ASSIGN(LoaderManager);
};
#endif // CHROME_BROWSER_TAB_CONTENTS_LOADER_MANAGER_H_
|
