1 // Copyright (c) 2011 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 "chrome/browser/ui/webui/screenshot_source.h"
6
7 #include "base/file_util.h"
8 #include "base/memory/ref_counted_memory.h"
9 #include "base/path_service.h"
10 #include "base/synchronization/waitable_event.h"
11 #include "base/task.h"
12 #include "chrome/common/chrome_paths.h"
13 #include "chrome/common/url_constants.h"
14 #include "content/browser/browser_thread.h"
15
16 static const char kCurrentScreenshot[] = "current";
17 #if defined(OS_CHROMEOS)
18 static const char kSavedScreenshots[] = "saved/";
19 #endif
20
21 static const char kScreenshotsRelativePath[] = "/Screenshots/";
22
23 #if defined(OS_CHROMEOS)
24 // Read the file from the screenshots directory into the read_bytes vector.
ReadScreenshot(const std::string & filename,std::vector<unsigned char> * read_bytes,base::WaitableEvent * read_complete)25 void ReadScreenshot(const std::string& filename,
26 std::vector<unsigned char>* read_bytes,
27 base::WaitableEvent* read_complete) {
28 read_bytes->clear();
29
30 FilePath fileshelf_path;
31 if (!PathService::Get(chrome::DIR_DEFAULT_DOWNLOADS, &fileshelf_path)) {
32 read_complete->Signal();
33 return;
34 }
35
36 FilePath file(fileshelf_path.value() + std::string(kScreenshotsRelativePath) +
37 filename);
38
39 int64 file_size = 0;
40 if (!file_util::GetFileSize(file, &file_size)) {
41 read_complete->Signal();
42 return;
43 }
44
45 // expand vector to file size
46 read_bytes->resize(file_size);
47 // read file into the vector
48 int bytes_read = 0;
49 if (!(bytes_read = file_util::ReadFile(file,
50 reinterpret_cast<char*>(
51 &read_bytes->front()),
52 static_cast<int>(file_size))))
53 read_bytes->clear();
54
55 // We're done, if successful, read_bytes will have the data
56 // otherwise, it'll be empty.
57 read_complete->Signal();
58 }
59
60 // Get a saved screenshot - read on the FILE thread.
GetSavedScreenshot(std::string filename)61 std::vector<unsigned char> GetSavedScreenshot(std::string filename) {
62 base::WaitableEvent read_complete(true, false);
63 std::vector<unsigned char> bytes;
64 BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
65 NewRunnableFunction(&ReadScreenshot, filename,
66 &bytes, &read_complete));
67 read_complete.Wait();
68 return bytes;
69 }
70 #endif
71
GetScreenshot(const std::string & full_path)72 std::vector<unsigned char> ScreenshotSource::GetScreenshot(
73 const std::string& full_path) {
74 // Strip the query param value - we only use it as a hack to ensure our
75 // image gets reloaded instead of being pulled from the browser cache
76 std::string path = full_path.substr(0, full_path.find_first_of("?"));
77 if (path == kCurrentScreenshot) {
78 return current_screenshot_;
79 #if defined(OS_CHROMEOS)
80 } else if (path.compare(0, strlen(kSavedScreenshots),
81 kSavedScreenshots) == 0) {
82 // Split the saved screenshot filename from the path
83 std::string filename = path.substr(strlen(kSavedScreenshots));
84
85 return GetSavedScreenshot(filename);
86 #endif
87 } else {
88 std::vector<unsigned char> ret;
89 // TODO(rkc): Weird vc bug, return std::vector<unsigned char>() causes
90 // the object assigned to the return value of this function magically
91 // change it's address 0x0; look into this eventually.
92 return ret;
93 }
94 }
95
ScreenshotSource(std::vector<unsigned char> * current_screenshot)96 ScreenshotSource::ScreenshotSource(
97 std::vector<unsigned char>* current_screenshot)
98 : DataSource(chrome::kChromeUIScreenshotPath, MessageLoop::current()) {
99 // Setup the last screenshot taken.
100 if (current_screenshot)
101 current_screenshot_ = *current_screenshot;
102 else
103 current_screenshot_.clear();
104 }
105
~ScreenshotSource()106 ScreenshotSource::~ScreenshotSource() {}
107
StartDataRequest(const std::string & path,bool is_incognito,int request_id)108 void ScreenshotSource::StartDataRequest(const std::string& path,
109 bool is_incognito,
110 int request_id) {
111 SendResponse(request_id, new RefCountedBytes(GetScreenshot(path)));
112 }
113
GetMimeType(const std::string &) const114 std::string ScreenshotSource::GetMimeType(const std::string&) const {
115 // We need to explicitly return a mime type, otherwise if the user tries to
116 // drag the image they get no extension.
117 return "image/png";
118 }
119