PrintPreview: Print Preview is not staying associated with initiator renderer.

chrome/browser/ui/webui/print_preview_data_source.h

+// Copyright (c) 2011 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_UI_WEBUI_PRINT_PREVIEW_DATA_SOURCE_H_
+#define CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_DATA_SOURCE_H_
+#pragma once
+
+#include <map>
+#include <string>
+#include <utility>
+
+#include "base/compiler_specific.h"
+#include "chrome/browser/ui/webui/chrome_url_data_manager.h"
+
+template<typename T> struct LeakySingletonTraits;
+
+class PrintPreviewUI;
+
+namespace base {
+class SharedMemory;
+}
+
+// PrintPreviewDataSource serves data for chrome://print requests.
+//
+// PrintPreviewDataSource owns the data and is responsible for freeing it when
+// either:
+//    a) there is a new data.
+//    b) When PrintPreviewDataSource is destroyed.
+//
+// The format for requesting data is as follows:
+// chrome://print/print.pdf/<PrintPreviewUIAddrStr>
+//
+// Parameters (< > required):
+//    <PrintPreviewUIAddrStr> = Print preview UI identifier.
+//
+// Example:
+//    chrome://print/print.pdf/0x7f5470fbe510

[Lei Zhang, 2011/05/26 01:48:31]

That's a weird looking URL. Can we do chrome://print/print.pdf?ab0123ef  ??

[kmadhusu, 2011/05/26 15:51:22]

Done.

+
+class PrintPreviewDataSource : public ChromeURLDataManager::DataSource {
+ public:
+  // A SharedMemory that contains the data for print preview,
+  // and the size of the print preview data in bytes.
+  typedef std::pair<base::SharedMemory*, uint32> PrintPreviewData;
+
+  typedef std::string PreviewUIAddrStr;

[Lei Zhang, 2011/05/26 01:48:31]

can we not have this typedef and just use std::string?

[kmadhusu, 2011/05/26 15:51:22]

Done.

+
+  // 1:1 relationship between PrintPreviewUI and preview data.
+  // Key: Print preview UI address string.
+  // Value: Preview data.
+  typedef std::map<PreviewUIAddrStr, PrintPreviewData> PreviewDataSrcMap;
+
+  PrintPreviewDataSource();
+  virtual ~PrintPreviewDataSource();
+
+  // Getter for the singleton.
+  static PrintPreviewDataSource* GetInstance();
+
+  // Remove the corresponding PrintPreviewUI entry from the map.
+  void RemoveEntry(const PreviewUIAddrStr& preview_ui_addr_str);

[Lei Zhang, 2011/05/26 01:48:31]

nit: Can you put them in a more logical order? Get/Set/Remove.

[kmadhusu, 2011/05/26 15:51:22]

Done.

+
+  // Set/Update the data entry in PreviewDataSrcMap.
+  void SetDataEntry(const PreviewUIAddrStr& preview_ui_addr_str,
+                    const PrintPreviewData& data);
+
+  // Get the data entry from PreviewDataSrcMap.
+  void GetDataEntry(const PreviewUIAddrStr& preview_ui_addr_str,
+                    PrintPreviewData* data);
+
+  // ChromeURLDataManager::DataSource implementation.
+  virtual void StartDataRequest(const std::string& path,
+                                bool is_incognito,
+                                int request_id) OVERRIDE;
+  virtual std::string GetMimeType(const std::string& path) const OVERRIDE;
+
+ private:
+  friend struct LeakySingletonTraits<PrintPreviewDataSource>;

[Lei Zhang, 2011/05/26 01:48:31]

Use DefaultSingletonTraits here. Then you can make the ctor/dtor private. See
other LeakySingletonTraits usage for examples.

[kmadhusu, 2011/05/26 15:51:22]

Removed the singleton traits.

+
+  PreviewDataSrcMap data_source_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrintPreviewDataSource);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_DATA_SOURCE_H_