1 // Copyright 2012 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef PRINTING_METAFILE_H_
6 #define PRINTING_METAFILE_H_
12 #include "base/component_export.h"
13 #include "base/containers/span.h"
14 #include "base/memory/read_only_shared_memory_region.h"
15 #include "build/build_config.h"
16 #include "printing/mojom/print.mojom-forward.h"
17 #include "printing/native_drawing_context.h"
21 #elif BUILDFLAG(IS_APPLE)
22 #include <CoreGraphics/CoreGraphics.h>
36 // This class plays metafiles from data stream (usually PDF or EMF).
37 class COMPONENT_EXPORT(PRINTING_METAFILE) MetafilePlayer {
40 MetafilePlayer(const MetafilePlayer&) = delete;
41 MetafilePlayer& operator=(const MetafilePlayer&) = delete;
42 virtual ~MetafilePlayer();
45 // The slow version of Playback(). It enumerates all the records and play them
46 // back in the HDC. The trick is that it skip over the records known to have
47 // issue with some printers. See Emf::Record::SafePlayback implementation for
49 virtual bool SafePlayback(printing::NativeDrawingContext hdc) const = 0;
51 #elif BUILDFLAG(IS_APPLE)
52 // Renders the given page into `rect` in the given context.
53 // Pages use a 1-based index. `autorotate` determines whether the source PDF
54 // should be autorotated to fit on the destination page. `fit_to_page`
55 // determines whether the source PDF should be scaled to fit on the
57 virtual bool RenderPage(unsigned int page_number,
58 printing::NativeDrawingContext context,
61 bool fit_to_page) const = 0;
62 #endif // BUILDFLAG(IS_WIN)
64 // Populates the buffer with the underlying data. This function should ONLY be
65 // called after the metafile is closed. Returns true if writing succeeded.
66 virtual bool GetDataAsVector(std::vector<char>* buffer) const = 0;
68 // Generates a read-only shared memory region for the underlying data. This
69 // function should ONLY be called after the metafile is closed. The returned
70 // region will be invalid if there is an error trying to generate the mapping.
71 virtual base::MappedReadOnlyRegion GetDataAsSharedMemoryRegion() const = 0;
73 // Determine if a copy of the data should be explicitly made before operating
74 // on metafile data. For security purposes it is important to not operate
75 // directly on the metafile data shared across processes, but instead work on
76 // a local copy made of such data. This query determines if such a copy needs
77 // to be made by the caller, since not all implementations are required to
78 // automatically do so.
79 // TODO(crbug.com/1135729) Eliminate concern about making a copy when the
80 // shared memory can't be written by the sender.
81 virtual bool ShouldCopySharedMemoryRegionData() const = 0;
83 // Identifies the type of encapsulated.
84 virtual mojom::MetafileDataType GetDataType() const = 0;
86 #if BUILDFLAG(IS_ANDROID)
87 // Similar to bool SaveTo(base::File* file) const, but write the data to the
88 // file descriptor directly. This is because Android doesn't allow file
89 // ownership exchange. This function should ONLY be called after the metafile
90 // is closed. Returns true if writing succeeded.
91 virtual bool SaveToFileDescriptor(int fd) const = 0;
93 // Saves the underlying data to the given file. This function should ONLY be
94 // called after the metafile is closed. Returns true if writing succeeded.
95 virtual bool SaveTo(base::File* file) const = 0;
96 #endif // BUILDFLAG(IS_ANDROID)
99 // This class creates a graphics context that renders into a data stream
100 // (usually PDF or EMF).
101 class COMPONENT_EXPORT(PRINTING_METAFILE) Metafile : public MetafilePlayer {
104 Metafile(const Metafile&) = delete;
105 Metafile& operator=(const Metafile&) = delete;
106 ~Metafile() override;
108 // Initializes a fresh new metafile for rendering. Returns false on failure.
109 // Note: It should only be called from within the renderer process to allocate
110 // rendering resources.
111 virtual bool Init() = 0;
113 // Initializes the metafile with `data`. Returns true on success.
114 // Note: It should only be called from within the browser process.
115 virtual bool InitFromData(base::span<const uint8_t> data) = 0;
117 // Prepares a context for rendering a new page with the given `page_size`,
118 // `content_area` and a `scale_factor` to use for the drawing. The units are
119 // in points (=1/72 in).
120 virtual void StartPage(const gfx::Size& page_size,
121 const gfx::Rect& content_area,
123 mojom::PageOrientation page_orientation) = 0;
125 // Closes the current page and destroys the context used in rendering that
126 // page. The results of current page will be appended into the underlying
127 // data stream. Returns true on success.
128 virtual bool FinishPage() = 0;
130 // Closes the metafile. No further rendering is allowed (the current page
131 // is implicitly closed).
132 virtual bool FinishDocument() = 0;
134 // Returns the size of the underlying data stream. Only valid after Close()
136 virtual uint32_t GetDataSize() const = 0;
138 // Copies the first `dst_buffer_size` bytes of the underlying data stream into
139 // `dst_buffer`. This function should ONLY be called after Close() is invoked.
140 // Returns true if the copy succeeds.
141 virtual bool GetData(void* dst_buffer, uint32_t dst_buffer_size) const = 0;
143 virtual gfx::Rect GetPageBounds(unsigned int page_number) const = 0;
144 virtual unsigned int GetPageCount() const = 0;
146 virtual printing::NativeDrawingContext context() const = 0;
148 #if BUILDFLAG(IS_WIN)
149 // "Plays" the EMF buffer in a HDC. It is the same effect as calling the
150 // original GDI function that were called when recording the EMF. `rect` is in
151 // "logical units" and is optional. If `rect` is NULL, the natural EMF bounds
153 // Note: Windows has been known to have stack buffer overflow in its GDI
154 // functions, whether used directly or indirectly through precompiled EMF
155 // data. We have to accept the risk here. Since it is used only for printing,
156 // it requires user intervention.
157 virtual bool Playback(printing::NativeDrawingContext hdc,
158 const RECT* rect) const = 0;
159 #endif // BUILDFLAG(IS_WIN)
161 // MetfilePlayer implementation.
162 bool GetDataAsVector(std::vector<char>* buffer) const override;
163 base::MappedReadOnlyRegion GetDataAsSharedMemoryRegion() const override;
164 #if !BUILDFLAG(IS_ANDROID)
165 bool SaveTo(base::File* file) const override;
166 #endif // !BUILDFLAG(IS_ANDROID)
169 } // namespace printing
171 #endif // PRINTING_METAFILE_H_