[gtk+] README: Refer to release notes online

[Matthias Clasen <matthiasc src gnome org>]

commit 14e33ab0f58fe11f973ff8f7615b3044b2113889
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon May 30 20:24:13 2016 -0400

    README: Refer to release notes online
    
    We don't want to maintain this information in two places,
    so just link to the online documentation here.

 README.in |  291 +-----------------------------------------------------------
 1 files changed, 5 insertions(+), 286 deletions(-)
---
diff --git a/README.in b/README.in
index 1dec201..9315f92 100644
--- a/README.in
+++ b/README.in
@@ -73,291 +73,10 @@ Patches should be in unified diff form. (The -up option to GNU diff)
 Even better are git-formatted patches. (Use git format-patch)
 
 
-Release notes for 3.20
-======================
+Release notes
+=============
 
-* The way theming works in GTK+ has been reworked fundamentally, to
-  implement many more CSS features and make themes more expressive.
-  As a result, custom CSS that is shipped with applications and third-
-  party themes will need adjustments. Widgets now use element names much
-  more than style classes; type names are no longer used in style matching.
-  Every widget now documents the element names it has and the style classes
-  it uses. The GTK+ inspector can also help with finding this information.
+Release notes for releases of GTK+ 3.x are part of the migration
+guide in the GTK+ documentation. See
 
-* GTK+ now uses internal subobjects (also known as gadgets) for allocating
-  and drawing widget parts. Applications that subclass GTK+ widgets may see
-  warnings if they override the size_allocate vfunc and don't chain up.
-  The proper way to subclass is to chain up in size_allocate. If you do not
-  want to do that for some reason, you have to override the draw vfunc as
-  well.
-
-* Several fixes for window sizing and window placement with client-side
-  decorations may affect applications that are saving and restoring window
-  sizes. The recommended best practice for this which is known to work with
-  client-side and server-side decorations and with older and newer versions
-  of GTK+ is to use gtk_window_get_size() to save window sizes and
-  gtk_window_set_default_size() to restore it.
-  See https://wiki.gnome.org/HowDoI/SaveWindowState for a detailed example.
-
-* Geometry handling in GtkWindow has been removed. If you are using the
-  functions gtk_window_resize_to_geometry, gtk_window_set_default_geometry,
-  gtk_window_parse_geometry or gtk_window_set_geometry_hints, you may need
-  to make some changes to your code.
-
-* GtkDrawingArea used to implicitly render the theme background before
-  calling the ::draw handler. This is no longer the case. If you rely
-  on having a theme-provided background, call gtk_render_background()
-  from your ::draw handler.
-
-* The GtkFileChooser interface prerequisite changed from GtkWidget
-  to GObject, allowing non-widget implementations of this interface.
-  This is a minor change in ABI, as applications are no longer guaranteed
-  that a GtkFileChooser also supports all GtkWidget methods. However, all
-  previously existing implementations still derive from GtkWidget, so no
-  existing code should break.
-
-* The way in which GtkLevelBar determines the offset to apply was a bit
-  inconsistent in the past; this has been fixed. Applications that are using
-  custom offsets should double-check that their levels look as expected.
-
-Release notes for 3.18
-======================
-
-* The GtkListBox model support that was introduced in 3.16 has been
-  changed to no longer call gtk_widget_show_all on rows created by
-  the create_widget_func. You need to manage the visibility of child
-  widgets yourself in your create_widget_func.
-
-* The alpha component of foreground colors that are applied to
-  GtkCellRendererText is no longer ignored. If you don't want your
-  text to be translucent, use opaque colors.
-
-Release notes for 3.16
-======================
-
-* GTK+ now includes an OpenGL rendering widget. To support GL on various
-  platforms, GTK+ uses libepoxy.
-
-* GTK+ no longer uses gtk-update-icon-cache during its build. The
-  --enable-gtk2-dependency configure option has been removed.
-
-* The introspection annotations for the x and y parameters of
-  GtkMenuPositionFunc have been corrected from 'out' to 'inout'.
-  If you are using such a function from language-bindings, this
-  may require adjustments.
-
-* The lookup order for actions that are activated via keyboard
-  accelerators has been changed to start at the currently focused
-  widget. If your application is making use fo nested action groups
-  via gtk_widget_insert_action_group, you may want to check that
-  this change does not upset your accelerators.
-
-* The GtkScrollable interface has gained a new vfunc, get_border,
-  that is used to position overshoot and undershoot indications that
-  are drawn over the content by GtkScrolledWindow. Unless your scrollable
-  has non-scrolling parts similar to treeview headers, there is no need
-  to implement this vfunc.
-
-* The GtkSearchEntry widget has gained a number of new signals that
-  are emitted when certain key sequences are seen. In particular, it
-  now handles the Escape key and emits ::stop-search. Applications that
-  expect to handle Escape themselves will need to be updated.
-
-Release notes for 3.14
-======================
-
-* A new state, GTK_STATE_FLAG_CHECKED, has been added for checked states
-  of radio and check buttons and menuitems. Applications that are using
-  GTK+ styles without widgets will need adjustments.
-
-* Adwaita is now the default theme on all platforms.
-
-* The icon theme code has become a little pickier about sizes and is not
-  automatically scaling icons beyond the limits defined in the icon theme
-  unless explicitly asked to do so with GTK_ICON_LOOKUP_FORCE_SIZE.
-
-* GTK+ now includes an interactive debugger which can be activated with
-  the keyboard shortcuts Ctrl-Shift-d or Ctrl-Shift-i. If these shortcuts
-  interfere with application keybindings, they can be disabled with the
-  setting org.gtk.Settings.Debug.enable-inspector-keybinding.
-
-* Most widgets have been ported to use the new gesture framework internally
-  for event handling. Traditional event handlers in derived widgets are still
-  being called.
-
-* Using GTK+ under X11 without the X Render extension has been observed
-  to be problematic. This combination is using code paths in cairo and
-  graphics drivers which are rarely tested and likely buggy.
-
-* GtkTextView is now using a pixel-cache internally, and is drawing
-  a background underneath the text. This can cause problems for applications
-  which assumed that they could draw things below and above the text
-  by chaining up in the ::draw implementation of their GtkTextView subclass.
-  As a short-term workaround, you can make the application apply a
-  custom theme to the text view with a transparent background. For
-  a proper fix, use the new ::draw_layer vfunc.
-
-Release notes for 3.12
-======================
-
-* GtkWidget had a hack where if opacity is 0.999 we set up an opacity
-  group when rendering the widget. This is no longer needed in 3.10,
-  and GtkStack doesn't use it anymore. It has been removed in 3.12.
-  GdStack is using it, so applications should be ported from GdStack
-  to GtkStack in 3.12.
-
-* GtkHeaderBar in 3.10 was not ordering its pack-end children in
-  the right way. This has been fixed in 3.12. Applications which
-  pack multiple widgets at the end of a headerbar will have to
-  be updated.
-
-* gtk_text_view_add_child_in_window has changed behaviour a bit.
-  It now always positions the child in buffer coordinates, where
-  it used to inconsistently scroll with the buffer but then go
-  reposition to a window-relative position on redraw.
-
-* A number of container widgets have been made more compliant with
-  the uniform CSS rendering model by making them render backgrounds
-  and borders. This may require some adjustments in applications that
-  were making assumptions about containers never rendering backgrounds.
-
-Release notes for 3.10
-======================
-
-* GDK has been changed to allow only a single screen per display.
-  Only the X11 backend had multiple screens before, and multi-screen
-  setups (not multi-monitor!) are very rare nowadays. If you really
-  need multiple X screens, open them as separate displays.
-
-* The behavior of GtkBox::expand has been changed to never propagate
-  up. Previously, this was happening inconsistently. If you want the
-  expand to propagate, use the GtkWidget h/v expand properties.
-  If you experience sizing problems with widgets in ported code,
-  carefully check the expand and fill flags of your boxes.
-
-* GtkBin no longer provides default implementations for
-  get_height_for_width, subclasses now have to provide their own
-  implementation if they need height-for-width functionality.
-
-* Widget state propagation has been changed. Historically, all of
-  active, prelight, selected, insensitive, inconsistent and backdrop
-  have been propagated to children. This has now been restricted
-  to just the insensitive and backdrop states. This mostly affects
-  theming.
-
-* The way widget drawing happens has changed. Earlier versions handled
-  one expose event per GdkWindow, each with a separate cairo_t. Now we
-  only handle the expose event on the toplevel and reuse the same
-  cairo_t (with the right translation and clipping) for the entire
-  widget hierarchy, recursing down via the GtkWidget::draw signal.
-  Having all rendering in the same call tree allows effects like
-  opacity and offscreen rendering of entire widget sub-hierarchies.
-  Generally this should not require any changes in widgets, but
-  code looking at e.g. the current expose event may see different
-  behavior than before.
-
-* The Gtk+ scrolling implementation has changed. gdk_window_scroll()
-  and gdk_window_move_region() no longer copy the region on the
-  window, but rather invalidate the entire scrolled region. This is
-  slightly slower, but allowed us to implement a offscreen surface
-  scrolling method which better fits modern hardware. Most scrolling
-  widgets in Gtk+ have been converted to use this model for scrolling,
-  but external widgets implementing scrolling using GdkWindow may see
-  some slowdown.
-
-Release notes for 3.8
-=====================
-
-* GtkIconInfo has changed from being a boxed type to a GObject. This
-  is technically an ABI change, but basically all existing code
-  will keep working if its used as a boxed type, and its not
-  possible to instantiate GtkIconInfos outside Gtk, so this is not
-  expected to be a big problem.
-
-Release notes for 3.6
-=====================
-
-* The accessibility bridge code that exports accessible objects
-  on the bus is now used by default; atk-bridge has been converted
-  into a library that GTK+ links against. To void the linking,
-  pass --without-atk-bridge when configuring GTK+.
-
-* GDK threading support has been deprecated. It is recommended to
-  use g_idle_add(), g_main_context_invoke() and similar funtions
-  to make all GTK+ calls from the main thread.
-
-* GTK+ now follows the XDG Base Directory specification for
-  user configuration and data files. In detail,
-  * $XDG_CONFIG_HOME/gtk-3.0/custom-papers is the new location
-    for $HOME/.gtk-custom-papers
-  * $XDG_CONFIG_HOME/gtk-3.0/bookmarks is the new location
-    for $HOME/.gtk-bookmarks
-  * $XDG_DATA_HOME/themes is preferred over $HOME/.themes
-  * $XDG_DATA_HOME/icons is preferred over $HOME/.icons.
-  Existing files from the old location will still be read
-  if the new location does not exist.
-
-* $HOME/.gtk-3.0 is no longer in the default module load path.
-  If you want to load modules from there, add it to the GTK_PATH
-  environment variable.
-
-Release notes for 3.4
-=====================
-
-* Scroll events have been separated from button events, and smooth
-  scrolling has been added with a separate event mask. Widgets now
-  need to have either GDK_SCROLL_MASK or GDK_SMOOTH_SCROLL_MASK in
-  their event mask to receive scroll events. In addition, the
-  GdkScrollDirection enumeration has gained a new member,
-  GDK_SCROLL_SMOOTH, so switch statements will have to be amended
-  to cover this case.
-
-* GTK+ now uses <Primary> instead of <Control> in keyboard accelerators,
-  for improved cross-platform handling. This should not affect
-  applications, unless they parse or create these accelerator
-  manually.
-
-* The tacit assumption that the Alt key corresponds to the MOD1
-  modifier under X11 is now a hard requirement.
-
-* The beagle search backend for the file chooser has been dropped.
-  Tracker is the only supported search backend on Linux now.
-
-* GtkNotebook has been changed to destroy its action widgets when
-  it gets destroyed itself. If your application is using action
-  widgets in notebooks, you may have to adjust your code to take
-  this into account.
-
-* GtkApplication no longer uses the gtk mainloop wrappers, so
-  it is no longer possible to use gtk_main_quit() to stop it.
-
-* The -uninstalled variants of the pkg-config files have been dropped.
-
-* Excessive dependencies have been culled from Requires: lines
-  in .pc files. Dependent modules may have to declare dependencies
-  that there were getting 'for free' in the past.
-
-Release notes for 3.2
-=====================
-
-* The accessible implementations for GTK+ widgets have been integrated
-  into libgtk itself, and the gail module does not exist anymore. This
-  change should not affect applications very much.
-
-Release notes for 3.0
-=====================
-
-* GTK+ 3 is a major new version of GTK+, which is parallel installable
-  with GTK+ 2.x. For information about porting applications from GTK+ 2.x
-  to GTK+ 3, see the file:
-
-  docs/reference/gtk/html/migrating.html
-
-  Or online at:
-
-  http://library.gnome.org/devel/gtk/3.0/migrating.html
-
-* Note that the library sonames in this release have been changed from
-  libgtk-3.0 and libgdk-3.0 to libgtk-3 and libgdk-3, to prevent the
-  library versions from going backwards, compared to the 2.90/91/99
-  releases. Applications will have to be recompiled.
+https://developer.gnome.org/gtk3/unstable/gtk-migrating-2-to-3.html