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Diffstat (limited to 'src/book.vala')
-rw-r--r-- | src/book.vala | 571 |
1 files changed, 571 insertions, 0 deletions
diff --git a/src/book.vala b/src/book.vala new file mode 100644 index 0000000..1aed281 --- /dev/null +++ b/src/book.vala @@ -0,0 +1,571 @@ +/* + * Copyright (C) 2009-2011 Canonical Ltd. + * Author: Robert Ancell <robert.ancell@canonical.com> + * + * This program is free software: you can redistribute it and/or modify it under + * the terms of the GNU General Public License as published by the Free Software + * Foundation, either version 3 of the License, or (at your option) any later + * version. See http://www.gnu.org/copyleft/gpl.html the full text of the + * license. + */ + +public class Book +{ + private List<Page> pages; + + private bool needs_saving; + + public signal void page_added (Page page); + public signal void page_removed (Page page); + public signal void reordered (); + public signal void cleared (); + public signal void needs_saving_changed (); + + public Book () + { + } + + public void clear () + { + pages = null; + cleared (); + } + + private void page_changed_cb (Page page) + { + set_needs_saving (true); + } + + public Page append_page (int width, int height, int dpi, ScanDirection scan_direction) + { + var page = new Page (width, height, dpi, scan_direction); + page.pixels_changed.connect (page_changed_cb); + page.crop_changed.connect (page_changed_cb); + + pages.append (page); + page_added (page); + set_needs_saving (true); + + return page; + } + + public void move_page (Page page, uint location) + { + pages.remove (page); + pages.insert (page, (int) location); + reordered (); + set_needs_saving (true); + } + + public void delete_page (Page page) + { + page.pixels_changed.disconnect (page_changed_cb); + page.crop_changed.disconnect (page_changed_cb); + page_removed (page); + pages.remove (page); + set_needs_saving (true); + } + + public uint get_n_pages () + { + return pages.length (); + } + + public Page get_page (int page_number) + { + if (page_number < 0) + page_number = (int) pages.length () + page_number; + return pages.nth_data (page_number); + } + + public uint get_page_index (Page page) + { + return pages.index (page); + } + + private File make_indexed_file (string uri, int i) + { + if (i == 0) + return File.new_for_uri (uri); + + /* Insert index before extension */ + var basename = Path.get_basename (uri); + string prefix = uri, suffix = ""; + var extension_index = basename.last_index_of_char ('.'); + if (extension_index >= 0) + { + suffix = basename.slice (extension_index, basename.length); + prefix = uri.slice (0, uri.length - suffix.length); + } + + return File.new_for_uri ("%s-%d%s".printf (prefix, i, suffix)); + } + + private void save_multi_file (string type, File file) throws Error + { + int i = 0; + foreach (var page in pages) + { + page.save (type, make_indexed_file (file.get_uri (), i)); + i++; + } + } + + private void save_ps_pdf_surface (Cairo.Surface surface, Gdk.Pixbuf image, double dpi) + { + var context = new Cairo.Context (surface); + context.scale (72.0 / dpi, 72.0 / dpi); + Gdk.cairo_set_source_pixbuf (context, image, 0, 0); + context.get_source ().set_filter (Cairo.Filter.BEST); + context.paint (); + } + + private void save_ps (File file) throws Error + { + var stream = file.replace (null, false, FileCreateFlags.NONE, null); + var writer = new PsWriter (stream); + var surface = writer.surface; + + foreach (var page in pages) + { + var image = page.get_image (true); + var width = image.get_width () * 72.0 / page.get_dpi (); + var height = image.get_height () * 72.0 / page.get_dpi (); + surface.set_size (width, height); + save_ps_pdf_surface (surface, image, page.get_dpi ()); + surface.show_page (); + } + } + + private uint8[]? compress_zlib (uint8[] data) + { + var stream = ZLib.DeflateStream (ZLib.Level.BEST_COMPRESSION); + var out_data = new uint8[data.length]; + + stream.next_in = data; + stream.next_out = out_data; + while (stream.avail_in > 0) + { + if (stream.deflate (ZLib.Flush.FINISH) == ZLib.Status.STREAM_ERROR) + break; + } + + if (stream.avail_in > 0) + return null; + + var n_written = data.length - stream.avail_out; + out_data.resize ((int) n_written); + + return out_data; + } + + private static void jpeg_init_cb (JPEG.Compress info) {} + private static bool jpeg_empty_cb (JPEG.Compress info) { return true; } + private static void jpeg_term_cb (JPEG.Compress info) {} + + private uint8[] compress_jpeg (Gdk.Pixbuf image, out size_t n_written) + { + var info = JPEG.Compress (); + var jerr = JPEG.ErrorManager (); + var dest_mgr = JPEG.DestinationManager (); + + info.err = jerr.std_error (); + info.create_compress (); + + info.image_width = image.get_width (); + info.image_height = image.get_height (); + info.input_components = 3; + info.in_color_space = JPEG.ColorSpace.RGB; /* TODO: JCS_GRAYSCALE? */ + info.set_defaults (); + + var max_length = info.image_width * info.image_height * info.input_components; + var data = new uint8[max_length]; + dest_mgr.next_output_byte = data; + dest_mgr.free_in_buffer = max_length; + dest_mgr.init_destination = jpeg_init_cb; + dest_mgr.empty_output_buffer = jpeg_empty_cb; + dest_mgr.term_destination = jpeg_term_cb; + info.dest = &dest_mgr; + + info.start_compress (true); + unowned uint8[] pixels = image.get_pixels (); + for (var r = 0; r < info.image_height; r++) + { + uint8* row[1]; + row[0] = (uint8*) pixels + r * image.get_rowstride (); + info.write_scanlines (row, 1); + } + info.finish_compress (); + n_written = max_length - dest_mgr.free_in_buffer; + + return data; + } + + private void save_pdf (File file) throws Error + { + var stream = file.replace (null, false, FileCreateFlags.NONE, null); + var writer = new PDFWriter (stream); + + /* Header */ + writer.write_string ("%%PDF-1.3\n"); + + /* Comment with binary as recommended so file is treated as binary */ + writer.write_string ("%%\xe2\xe3\xcf\xd3\n"); + + /* Catalog */ + var catalog_number = writer.start_object (); + writer.write_string ("%u 0 obj\n".printf (catalog_number)); + writer.write_string ("<<\n"); + writer.write_string ("/Type /Catalog\n"); + //FIXMEwriter.write_string ("/Metadata %u 0 R\n".printf (catalog_number + 1)); + writer.write_string ("/Pages %u 0 R\n".printf (catalog_number + 1)); //+2 + writer.write_string (">>\n"); + writer.write_string ("endobj\n"); + + /* Metadata */ + /* FIXME writer.write_string ("\n"); + number = writer.start_object (); + writer.write_string ("%u 0 obj\n".printf (number)); + writer.write_string ("<<\n"); + writer.write_string ("/Type /Metadata\n"); + writer.write_string ("/Subtype /XML\n"); + writer.write_string ("/Length %u\n".printf (...)); + writer.write_string (">>\n"); + writer.write_string ("stream\n"); + // ... + writer.write_string ("\n"); + writer.write_string ("endstream\n"); + writer.write_string ("endobj\n");*/ + + /* Pages */ + writer.write_string ("\n"); + var pages_number = writer.start_object (); + writer.write_string ("%u 0 obj\n".printf (pages_number)); + writer.write_string ("<<\n"); + writer.write_string ("/Type /Pages\n"); + writer.write_string ("/Kids ["); + for (var i = 0; i < get_n_pages (); i++) + writer.write_string (" %u 0 R".printf (pages_number + 1 + (i*3))); + writer.write_string (" ]\n"); + writer.write_string ("/Count %u\n".printf (get_n_pages ())); + writer.write_string (">>\n"); + writer.write_string ("endobj\n"); + + for (var i = 0; i < get_n_pages (); i++) + { + var page = get_page (i); + var image = page.get_image (true); + var width = image.get_width (); + var height = image.get_height (); + unowned uint8[] pixels = image.get_pixels (); + var page_width = width * 72.0 / page.get_dpi (); + var page_height = height * 72.0 / page.get_dpi (); + + int depth = 8; + string color_space = "DeviceRGB"; + string? filter = null; + char[] width_buffer = new char[double.DTOSTR_BUF_SIZE]; + char[] height_buffer = new char[double.DTOSTR_BUF_SIZE]; + uint8[] data; + if (page.is_color ()) + { + depth = 8; + color_space = "DeviceRGB"; + var data_length = height * width * 3 + 1; + data = new uint8[data_length]; + for (var row = 0; row < height; row++) + { + var in_offset = row * image.get_rowstride (); + var out_offset = row * width * 3; + for (var x = 0; x < width; x++) + { + var in_o = in_offset + x*3; + var out_o = out_offset + x*3; + + data[out_o] = pixels[in_o]; + data[out_o+1] = pixels[in_o+1]; + data[out_o+2] = pixels[in_o+2]; + } + } + } + else if (page.get_depth () == 2) + { + int shift_count = 6; + depth = 2; + color_space = "DeviceGray"; + var data_length = height * ((width * 2 + 7) / 8); + data = new uint8[data_length]; + var offset = 0; + data[offset] = 0; + for (var row = 0; row < height; row++) + { + /* Pad to the next line */ + if (shift_count != 6) + { + offset++; + data[offset] = 0; + shift_count = 6; + } + + var in_offset = row * image.get_rowstride (); + for (var x = 0; x < width; x++) + { + var p = pixels[in_offset + x*3]; + if (p >= 192) + data[offset] |= 3 << shift_count; + else if (p >= 128) + data[offset] |= 2 << shift_count; + else if (p >= 64) + data[offset] |= 1 << shift_count; + if (shift_count == 0) + { + offset++; + data[offset] = 0; + shift_count = 6; + } + else + shift_count -= 2; + } + } + } + else if (page.get_depth () == 1) + { + int mask = 0x80; + + depth = 1; + color_space = "DeviceGray"; + var data_length = height * ((width + 7) / 8); + data = new uint8[data_length]; + var offset = 0; + data[offset] = 0; + for (var row = 0; row < height; row++) + { + /* Pad to the next line */ + if (mask != 0x80) + { + offset++; + data[offset] = 0; + mask = 0x80; + } + + var in_offset = row * image.get_rowstride (); + for (var x = 0; x < width; x++) + { + if (pixels[in_offset+x*3] != 0) + data[offset] |= (uint8) mask; + mask >>= 1; + if (mask == 0) + { + offset++; + data[offset] = 0; + mask = 0x80; + } + } + } + } + else + { + depth = 8; + color_space = "DeviceGray"; + var data_length = height * width + 1; + data = new uint8 [data_length]; + for (var row = 0; row < height; row++) + { + var in_offset = row * image.get_rowstride (); + var out_offset = row * width; + for (var x = 0; x < width; x++) + data[out_offset+x] = pixels[in_offset+x*3]; + } + } + + /* Compress data */ + var compressed_data = compress_zlib (data); + if (compressed_data != null) + { + /* Try if JPEG compression is better */ + if (depth > 1) + { + size_t jpeg_length; + var jpeg_data = compress_jpeg (image, out jpeg_length); + if (jpeg_length < compressed_data.length) + { + filter = "DCTDecode"; + data = jpeg_data; + } + } + + if (filter == null) + { + filter = "FlateDecode"; + data = compressed_data; + } + } + + /* Page */ + writer.write_string ("\n"); + var number = writer.start_object (); + writer.write_string ("%u 0 obj\n".printf (number)); + writer.write_string ("<<\n"); + writer.write_string ("/Type /Page\n"); + writer.write_string ("/Parent %u 0 R\n".printf (pages_number)); + writer.write_string ("/Resources << /XObject << /Im%d %u 0 R >> >>\n".printf (i, number+1)); + writer.write_string ("/MediaBox [ 0 0 %s %s ]\n".printf (page_width.format (width_buffer, "%.2f"), page_height.format (height_buffer, "%.2f"))); + writer.write_string ("/Contents %u 0 R\n".printf (number+2)); + writer.write_string (">>\n"); + writer.write_string ("endobj\n"); + + /* Page image */ + writer.write_string ("\n"); + number = writer.start_object (); + writer.write_string ("%u 0 obj\n".printf (number)); + writer.write_string ("<<\n"); + writer.write_string ("/Type /XObject\n"); + writer.write_string ("/Subtype /Image\n"); + writer.write_string ("/Width %d\n".printf (width)); + writer.write_string ("/Height %d\n".printf (height)); + writer.write_string ("/ColorSpace /%s\n".printf (color_space)); + writer.write_string ("/BitsPerComponent %d\n".printf (depth)); + writer.write_string ("/Length %d\n".printf (data.length)); + if (filter != null) + writer.write_string ("/Filter /%s\n".printf (filter)); + writer.write_string (">>\n"); + writer.write_string ("stream\n"); + writer.write (data); + writer.write_string ("\n"); + writer.write_string ("endstream\n"); + writer.write_string ("endobj\n"); + + /* Page contents */ + var command = "q\n%s 0 0 %s 0 0 cm\n/Im%d Do\nQ".printf (page_width.format (width_buffer, "%f"), page_height.format (height_buffer, "%f"), i); + writer.write_string ("\n"); + number = writer.start_object (); + writer.write_string ("%u 0 obj\n".printf (number)); + writer.write_string ("<<\n"); + writer.write_string ("/Length %d\n".printf (command.length + 1)); + writer.write_string (">>\n"); + writer.write_string ("stream\n"); + writer.write_string (command); + writer.write_string ("\n"); + writer.write_string ("endstream\n"); + writer.write_string ("endobj\n"); + } + + /* Info */ + writer.write_string ("\n"); + var info_number = writer.start_object (); + writer.write_string ("%u 0 obj\n".printf (info_number)); + writer.write_string ("<<\n"); + writer.write_string ("/Creator (Simple Scan %s)\n".printf (Config.VERSION)); + writer.write_string (">>\n"); + writer.write_string ("endobj\n"); + + /* Cross-reference table */ + var xref_offset = writer.offset; + writer.write_string ("xref\n"); + writer.write_string ("1 %zu\n".printf (writer.object_offsets.length ())); + foreach (var offset in writer.object_offsets) + writer.write_string ("%010zu 0000 n\n".printf (offset)); + + /* Trailer */ + writer.write_string ("trailer\n"); + writer.write_string ("<<\n"); + writer.write_string ("/Size %zu\n".printf (writer.object_offsets.length ())); + writer.write_string ("/Info %u 0 R\n".printf (info_number)); + writer.write_string ("/Root %u 0 R\n".printf (catalog_number)); + //FIXME: writer.write_string ("/ID [<...> <...>]\n"); + writer.write_string (">>\n"); + writer.write_string ("startxref\n"); + writer.write_string ("%zu\n".printf (xref_offset)); + writer.write_string ("%%%%EOF\n"); + } + + public void save (string type, File file) throws Error + { + if (strcmp (type, "jpeg") == 0) + save_multi_file ("jpeg", file); + else if (strcmp (type, "png") == 0) + save_multi_file ("png", file); + else if (strcmp (type, "tiff") == 0) + save_multi_file ("tiff", file); + else if (strcmp (type, "ps") == 0) + save_ps (file); + else if (strcmp (type, "pdf") == 0) + save_pdf (file); + } + + public void set_needs_saving (bool needs_saving) + { + var needed_saving = this.needs_saving; + this.needs_saving = needs_saving; + if (needed_saving != needs_saving) + needs_saving_changed (); + } + + public bool get_needs_saving () + { + return needs_saving; + } +} + +private class PDFWriter +{ + public size_t offset = 0; + public List<uint> object_offsets; + private FileOutputStream stream; + + public PDFWriter (FileOutputStream stream) + { + this.stream = stream; + } + + public void write (uint8[] data) + { + try + { + stream.write_all (data, null, null); + } + catch (Error e) + { + warning ("Error writing PDF: %s", e.message); + } + offset += data.length; + } + + public void write_string (string text) + { + write ((uint8[]) text.to_utf8 ()); + } + + public uint start_object () + { + object_offsets.append ((uint)offset); + return object_offsets.length (); + } +} + +public class PsWriter +{ + public Cairo.PsSurface surface; + public FileOutputStream stream; + + public PsWriter (FileOutputStream stream) + { + this.stream = stream; + surface = new Cairo.PsSurface.for_stream (write_cairo_data, 0, 0); + } + + private Cairo.Status write_cairo_data (uint8[] data) + { + try + { + stream.write_all (data, null, null); + } + catch (Error e) + { + warning ("Error writing data: %s", e.message); + return Cairo.Status.WRITE_ERROR; + } + + return Cairo.Status.SUCCESS; + } +} |