List of features to be implemented (not in any particular order)
----------------------------------------------------------------

- collaborative editing (see discussion with Erik Demaine)
- porting to MacOS; merge Nokia port
- multiple-scenario undo history

- collaborative: allow non-x86 endianness (for ints, for floats?)
- collaborative: have an initial undo item = contents of the initial
  xoj file + attachments for bitmap, pdf, and ps backgrounds

- cleanup of undo history (keep track of refcounts, delete old undo)
  save-and-clear-undo ?

- RandR / recalibration awareness? - NOT NEEDED ANYMORE?
  (e.g. if xinput events are far away from core events, re-query geometry?)
   or see if removing the GTK bugfix would help? -- e.g. by recalling an
   internal gtk init function?
  Also allow for SIGUSR1 to recalibrate (so rotate scripts could pkill
  xournal). (cf #2944459). Recalibration probably requires talking directly 
  to X server to query input device geometry and compensate for GTK.


- image patch related:
  - paste and selresize don't put rectangle at top
  - need option for image mode to revert to previous tool?
  - optimize storage of embedded images by detecting duplicates (D. German)

BUGS:
- lingering issues with synaptics touchpads? (#2872667)
 (todo) - set device to Absolute mode at startup? (GDK doesn't expose API,
          cf XSetDeviceMode() in /usr/include/X11/extensions/XInput.h)
- color picker into canvas doesn't work in GTK+ 2.16 (should disable
   xinput first?)
- export to PDF should see cropbox size if smaller, and map the
   cropbox -- not the entire page -- to the page area! (2009-11-18 forum)

BEHAVIOR TODO:
- option to have "Save Prefs" save current brushes as settings, not defaults
- method to map more general devices to specific tools or to Ignore
  (e.g.: X220T ignore trackpoint; map touchscreen to Hand, eraser to Eraser)

WIN32:
- test further
- write an installer
- bug: opening files with accents in name?
- bug: cairo-scaled-font in printing? (2009-11-18 bug tracker)
- bug: printf() sometimes generates stroke coordinates 1.#J -1.#J  (???)
     (filter out inf, -inf, nan, very large values when saving ???)

PATCHES TO INCORPORATE:

- ezyang e-mail of 11/28/2011: patches in Ubuntu to fix PDF showing up?
http://archive.ubuntu.com/ubuntu/pool/universe/x/xournal/xournal_0.4.5-3.debian.tar.gz
actually not necessary anymore? (ezyang 12/2/2011)

- tauu e-mail of 12/1/2011: 8 small patches for win32, uploaded on tracker
https://sourceforge.net/tracker/index.php?func=detail&aid=3447356&group_id=163434&atid=827735

- patch: add Alt-Up/Dn accelerators for show/hide layer. See
  show_hide_layer.patch

* my own patch noresize_background_v1.patch  (also in xournal-working/)

** patch: ortho/snap (revised Apr 13 2009)
   xournal_ortho_snap_patch_4 (by Josef Pavlicek)

** patch (Ian-Woo Kim): multicolumn mode + LASSO SELECTION
   xournal_lasso_multipage_zoom_button_20090620.patch

** autosave patch (Edward Yang) (should fix: optional only, w/ menu + cfgfile
   entries; fix: should clean up autosave.xoj.bg* files too; config interval)
   0001-Implement-autosave-for-documents-revised.patch (2 seconds after
   modification, vs original 5 seconds)
   *** NEW VERSION: #2881919 (autosave for 0.4.5, w/ some changes)
   NB: last modif should be triggered by prepare_new_undo() and undo/redo?
   *** NEW VERSION: with threading, by Man, e-mail 12/10/2009 10:51pm

** customize paper ruling (Gautam Iyer e-mail Nov 30 2009 / SF tracker)

** cairo export to PNG (Man = Paulo Neves, e-mail Feb 3 '10, saved as
  cairo-png-rendering.diff.txt (refactor printing of page to cairo surface
  with the gtk-print code).

- patch by S. Guest
  shortcut to increase/decrease text font size by 1 point (?) - acts just
  as if one had clicked font sel box and resized (affects sel text + cur font)

- make line spacing in text objects customizable: to a fixed scaling factor,
  a fixed number of units, or the paper ruling (esp. the latter!!)

- page size dialog box should have a check button to keep background size
  the same (so rescaling creates margin around bitmap or PDF background).
  This will need an extension to the file format, to allow a page background
  to have a different size from the page itself.

- option to map device named "touch" to hand tool? (like "Eraser tip")

- roadmap towards SVG support: see 1/25/2010 Mark Edgington email & reply
  (1) export to SVG (using pages and groups for pages and layers; 
  use comment tags to make export nonlossy;
  (2) import from this subset of SVG;
  (3) add SVG to the file-open and save formats

- roadmap towards PDF encapsulation: see 1/29/2010 forum posts
  When exporting to PDF, don't just append our annotations as PDF code but
  also include the .xoj file within the pdf, and ensure the initial pdf is
  well-delimited from the rest. When opening a PDF that includes such
  markings, discard the annotation part of the PDF and open the embedded xoj
  instead. Later, offer such PDF as a file-open and save format (even when
  there's no PDF background being annotated!!).

*** should have Open, Save, Save As manipulate at least 3 formats:
  - XOJ
  - PDF with embedded xoj file in an object (opens with annot. in PDF viewer,
    with background only + separate xoj in xournal)
  - SVG (subset only)
  additionally, should have "print to": printer, PDF, SVG, bitmap.

- allow djvu and other backgrounds (but then can't export to PDF)

- PDF bg memory usage throttling / delete oldest pdf backgrounds
- replace ttsubset by something more modern? (eg. from cairo ?)
- auto-hide patch from ~/prog/src/xournal-autohide/ ?
     (check for cpu usage; handle BOTH edges
      and only (un)hide stuff at the correct edge!)
** UI update (Bob McElrath) -- eliminating status bar, compact layout,
   "compact interface" by default; themes, with line in config file
   to load pixmaps from pixmaps/$THEME/ (see Jan 9, 2009 emails)
- horizontal mode instead of dual-view / multicolumn ?
** "new page before/after" on a PDF bg page should ask: same page, other page of
  PDF file, default paper
** should also have in Journal -> Paper style the option "Pdf page ..."
  which then lets us change the page number.
- new recognizer icon (andruk on patches tracker)
- recognizer: if variable-width, associate average width
- recognizer should snap to existing recognized geometric shapes
- patch to find text in PDF (dmg = Daniel German, Nov 13 2009)

- search through text (xoj and PDF background) (with highlight? forwd/backwd)
  (see evince). Also: ability to select rectangle on PDF bg and copy-paste
  as bitmap or as text.

- improve recognizer: two passes for polygons (low tolerance, then higher)
  to better detect elongated rectangles? (if low tolerance recognizer
  doesn't get a rectangle, then use higher tolerance for everything else,
  since otherwise there's too much risk of splitting a segment into 2)
- snap-to-grid (also for ruler & recognizer vertices)
  and maybe also snap-to-vertices (option for ruler and recognizer)?
- config option: config save current tool options instead of default ones

- bug in truetype subset generation w/ Adobe 9, see if gtk-print any better?

- drag-and-drop, copy-paste text & images directly into xournal
- proximity detection: eraser proximity switches mapping? 
  proximity out removes cursor until next motionnotify?

- render page to bitmap: for export, preview, and copy-paste
    (render using libart, see how gnomecanvas does it?)
    NO: render using Cairo !!!
    (copy-paste: config option to render only current layer or all below?)
- cut-and-paste of selection into other apps (as bitmap; as SVG?)

- navigation sidebar with bitmap page previews
- bitmap preview for document icon in desktop environments?
- "organizer" side panel (hierarchy of notes), cf. gjots
- maintain e-library: table of md5sums of pdfs with associations
  to the corresponding xoj's absolute paths (cf. forum topic
  "Use MD5..." of Dec 2009)

- see iRex code for generic viewer + PDF plugin including caching,
  throttling etc. (Marcel Hendrickx email of Sep 11 '09) 

- allow toolbar to go vertical
- toolbar buttons should react to button 2/3 click to modify settings
  for that tool!!

- paste text directly into xournal, from xournal?
    (instead of starting a text item and pasting into/from it)
- insert links (to URLs; within document/to other xoj? hand mode navigates)
- a command + keyboard shortcut to switch mappings (1<->2, 1<->3, 2<->3)
     (A. Rechnitzer Sept 11, 2007)
- modify encoding of TrueType font subsets or provide cmap so pdf text
  can be extracted

- smoothing of strokes (for users without tablets / with deficient drivers)
- lasso tool
- add config option to limit total memory usage for PDF bitmaps
- ability to select entire page for copy-paste (as bitmap / reorder xournal)
- copy/paste of an entire page (beware if PDF bg is not compatible!)

- convert to/from Jarnal format; to/from MS Journal format???
- export as SVG, as bitmap (use Cairo for this)
- improved PDF viewer features (search text, hyperlink, page borders...)
   (using full poppler api ?)
- search text: among PDF background (using poppler); among text annotations

- use system paper size as default (/etc/papersize)
- sticky notes (anchor visually text box to a bg location)
- use relative paths for bg documents (e.g. annotated PDF)
- flush display queue when drawing over a slow X server?
- more paper customization (in particular, 1/2 inch graph paper)
    (2 custom papers with settings in config file? 
     a folder with blank PDF or xoj papers and quick-access?)
    (also: engineering paper; isometric paper -- Dan Ott  Sep 4 '09)
- option to map a button to a context menu (incl. tool selection, ...)
- option to map a button to "undo"
- xournal_page-shadow.diff (Martin Kiefel Feb 5 2007)
- xoj2pdf on command line
- 'insert blank page after' command (more useful in PDF annot !)
- load images as bg if given on command-line (as with PDF on commandline)
- lasso selection tool (see shoffsta patch)
     (http://shoffsta.afraid.org/Projects/Xournal/)
- flatten (incl undo/redo...) - enabled only if nlayers>1
- color chooser (papercolor, pen color); have default colors and a history
  appear as palette in there!
- printing: print-options, save printer settings (throughout a session,
   and on disk) (maybe a separate config file .xournal/gnome-print-settings)
- help index
- option for highlighter to be always at bottom of its layer
- more pen/highlighter shapes (chisel)
- slanted tip pens (calligraphy)
- toolbar buttons to access custom preset tools (e.g. text or pen with settings)
- text boxes with opaque background
- recalibration upon screen resize / compensation for miscalibration
    (use ConfigureNotify event and XInput? cf "Bugs" tracker 08/2007)
- find a better behavior for vertical space tool across page boundaries ?
   config options? 1) when there's not enough space at bottom of page:
                       - resize the page
                       - move stuff to next page
                       - move stuff to a new page
                   2) when moving to another page:
                       - move everything
                       - move only what doesn't fit (??? looks hard)
   option for vert space tool to also move the background??
   (PDF: cut-and-crop by running PDF code twice with 2 different clipboxes?)
- option to save all annotated files within the .xoj
- non-antialiased version for handhelds
- customize autogenerated save file names 
- layer dialog box to set visibility status of each layer regardless of
  which layer is being edited
- option to link layer creation and visibility status for all pages
  (Eric Borghs 04/15/08)
- display corruption on scroll down when bottom of window is obscured??
  (probably a gnomecanvas or X bug -- expose event generated for wrong
  region, or not processed?)
- autosave at a regular interval in a given location
- keep only a few pages of a PDF file in memory at any given time; generate
  pages by parsing pdf info rather than generating bitmaps for all of them.
- win32 port (Matteo Abrate)
- snap-to-grid tool? (Matteo Abrate)
- EPOS 7/24/07: Thumbnails pane
- EPOS: Connect to EPOS api which sends A4 mapped points
- EPOS: Cut and Paste into OpenOffice applications and the GIMP (as bitmap??)
- EPOS: Export pages to pictures in the Jpg and Png formats.
- EPOS: Rotate Ink in custom angle.
- handwriting recognition???? (cellwriter?) unlikely. we don't have grids
  see galileon comment on 2008-07-29 to tracker #1925309: word recognizer
- handwritten stroke search in document (see cellwriter?)
  (correlate inertia-normalized strokes in lift to unit cotangent bundle?)
- option: export to PDF with incremental pages for successive layers
    (for presentations) (Daniel Brugarth 8/18/07)
- Samuel Hoffstaetter: lasso, gettext localization, sidebar thumbnails, ...
- YoYo Siska patch for desktop mode ??
- Vivek Ayer: rotate paper wrt screen (for environments where display
  rotation doesn't work): gnome_canvas_item_affine_relative(canvas->root, ...)
  would rotate all but text items (still need to modify scroll bbox, and
  adjust event coordinates by inverse rotation).
- rotate PDF background pages (individually wrt each other, see #2099935)
- switch to libglade, and allow customization of key shortcuts (accels)

- command to copy a selected shape to a keybinding that will paste it
  (so one can define symbols to insert into typed notes)  (e.g. "be able
  to bind Ctrl-B to draw a \beta" for class notes). (shape, binding) sets are
  local to one session (different for different classes; but save them into
  the xoj file maybe ?) [Felix Giannelia 09/29/2009]
