fix harmless warnings (mostly about unused parameters/variables)

[wxWidgets.git] / docs / changes.txt

-------------------------------------------------------------------------------
                             wxWidgets Change Log
-------------------------------------------------------------------------------

INCOMPATIBLE CHANGES SINCE 2.8.x
================================


        Notice that these changes are described in more details in
        the "Changes Since wxWidgets 2.8" section of the manual,
        please read it if the explanation here is too cryptic.


Unicode-related changes
-----------------------

The biggest changes in wxWidgets 3.0 are the changes due to the merge of the
old ANSI and Unicode build modes in a single build. See the Unicode overview
in the manual for more details but here are the most important incompatible
changes:

- Many wxWidgets functions taking "const wxChar *" have been changed to take
  either "const wxString&" (so that they accept both Unicode and ANSI strings;
  the argument can't be NULL anymore in this case) or "const char *" (if the
  strings are always ANSI; may still be NULL). This change is normally
  backwards compatible except:

  a) Virtual functions: derived classes versions must be modified to take
     "const wxString&" as well to make sure that they continue to override the
     base class version.

  b) Passing NULL as argument: as NULL can't be unambiguously converted to
     wxString, in many cases code using it won't compile any more and NULL
     should be replaced with an empty string.

- Functions returning "const wxChar *" were changed as well. Mostly they now
  return wxString which is then transparently convertible to either "const char
  *" or "const wchar_t *" but in some cases, notably wxDateTime::ParseXXX(),
  the returned string could be NULL and so a separate helper class is used. If
  you obtain compilation errors because of this, you can always correct them by
  explicitly assigning the function return value to a variable of wanted type.
  A slightly more intrusive but better solution is to use ParseXXX() version
  with wxString::const_iterator output parameter which simply returns bool to
  indicate the parsing success.

- Some structure fields which used to be of type "const wxChar *" (such as
  wxCmdLineEntryDesc::shortName, longName and description fields) are now of
  type "const char *", you need to remove wxT() or _T() around the values used
  to initialize them (which should normally always be ASCII).

- wxIPC classes didn't work correctly in Unicode build before, this was fixed
  but at a price of breaking backwards compatibility: many methods which used
  to work with "wxChar *" before use "void *" now (some int parameters were
  also changed to size_t). While wxIPC_TEXT can still be used to transfer 7
  bit text, the new wxIPC_UTF8TEXT format is used for transferring wxStrings.
  Also notice that connection classes should change the parameter types of
  their overridden OnExecute() or override a more convenient OnExec() instead.


wxODBC and contrib libraries removal
------------------------------------

wxODBC library was unmaintained since several years and we couldn't continue
supporting it any longer so it was removed. Please use any of the other open
source ODBC libraries in the future projects.

Also the "applet", "deprecated", "fl", "mmedia" and "plot" contrib libraries
were removed as they were unmaintained and broken since several years.
The "gizmos", "ogl", "net" and "foldbar" contribs have been moved to
wxCode (see http://wxcode.sourceforge.net/complist.php); they are now
open for futher development by volunteers.

The "stc" and "svg" contribs instead have been moved respectively into a new
"official" library stc and in the core lib.


Changes in behaviour not resulting in compilation errors, please read this!
---------------------------------------------------------------------------

- Default location of wxFileConfig files has changed under Windows, you will
  need to update your code if you access these files directly.

- wxWindow::IsEnabled() now returns false if a window parent (and not
  necessarily the window itself) is disabled, new function IsThisEnabled()
  with the same behaviour as old IsEnabled() was added.

- Generating wxNavigationKeyEvent events doesn't work any more under wxGTK (and
  other platforms in the future), use wxWindow::Navigate() or NavigateIn()
  instead.

- Sizers distribute only the extra space between the stretchable items
  according to their proportions and not all available space. We believe the
  new behaviour corresponds better to user expectations but if you did rely
  on the old behaviour you will have to update your code to set the minimal
  sizes of the sizer items to be in the same proportion as the items
  proportions to return to the old behaviour.

- wxWindow::Freeze/Thaw() are not virtual any more, if you overrode them in
  your code you need to override DoFreeze/Thaw() instead now.

- wxCalendarCtrl has native implementation in wxGTK, but it has less features
  than the generic one. The native implementation is used by default, but you
  can still use wxGenericCalendarCtrl instead of wxCalendarCtrl in your code if
  you need the extra features.

- wxDocument::FileHistoryLoad() and wxFileHistory::Load() now take const
  reference to wxConfigBase argument and not just a reference, please update
  your code if you overrode these functions and change the functions in the
  derived classes to use const reference as well.

- Under MSW wxExecute() arguments are now always properly quoted, as under
  Unix, and so shouldn't contain quotes unless they are part of the argument.

- wxDocument::OnNewDocument() doesn't call OnCloseDocument() any more.

- If you use wxScrolledWindow::SetTargetWindow() you must implement its
  GetSizeAvailableForScrollTarget() method, please see its documentation for
  more details.

- Processing of pending events now requires a running event loop.
  Thus initialization code (e.g. showing a dialog) previously done in wxApp::OnRun()
  or equivalent function should now be done into wxApp::OnEventLoopEnter().
  See wxApp::OnEventLoopEnter() and wxApp::OnEventLoopExit() docs for more info.

- wxLoadFileSelector() now allows the user to select existing files only.

- Erase background events are now not generated at all when background style is
  changed. See the updated wxWindow::SetBackgroundStyle() description in the
  manual for more details.

- wxTreeCtrl::GetSelection now asserts if the tree has the wxTR_MULTIPLE style.
  Instead use GetSelections() for multiple items; or if you want only the 
  single item last touched, the new wxTreeCtrl::GetFocusedItem.


Changes in behaviour which may result in compilation errors
-----------------------------------------------------------

- WXWIN_COMPATIBILITY_2_4 doesn't exist any more, please update your code if
  you still relied on features deprecated since version 2.4

- wxDC classes hierarchy has changed, if you derived any classes from wxDC you
  need to review them as wxDC doesn't have any virtual methods any longer and
  uses delegation instead of inheritance to present different behaviours.

- wxWindow::ProcessEvent() (and other wxEvtHandler methods inherited by wxWindow)
  has been made protected to prevent wrongly using it instead of correct
  GetEventHandler()->ProcessEvent().
  New ProcessWindowEvent() was added for convenience.

- Return type of wxString::operator[] and wxString::iterator::operator* is no
  longer wxChar (i.e. char or wchar_t), but wxUniChar. This is not a problem
  in vast majority of cases because of conversion operators, but it can break
  code that depends on the result being wxChar.

- The value returned by wxString::c_str() cannot be casted to non-const char*
  or wchar_t* anymore. The solution is to use newly added wxString methods
  char_str() (which returns a buffer convertible to char*) or wchar_str()
  (which returns a buffer convertible to wchar_t*). These methods are
  available in wxWidgets 2.8 series beginning with 2.8.4 as well.

- The value returned by wxString::operator[] or wxString::iterator cannot be
  used in switch statements anymore, because it's a class instance. Code like
  this won't compile:
     switch (str[i]) { ... }
  and has to be replaced with this:
     switch (str[i].GetValue()) { ... }

- Return type of wxString::c_str() is now a helper wxCStrData struct and not
  const wxChar*. wxCStrData is implicitly convertible to both "const char *"
  and "const wchar_t *", so this only presents a problem if the compiler cannot
  apply the conversion. This can happen in 2 cases:

  + There is an ambiguity because the function being called is overloaded to
    take both "const char *" and "const wchar_t *" as the compiler can't choose
    between them. In this case you may use s.wx_str() to call the function
    matching the current build (Unicode or not) or s.mb_str() or s.wc_str() to
    explicitly select narrow or wide version of it.

    Notice that such functions are normally not very common but unfortunately
    Microsoft decided to extend their STL with standard-incompatible overloads
    of some functions accepting "const wchar_t *" so you may need to replace
    some occurrences of c_str() with wx_str() when using MSVC 8 or later.

  + Some compilers, notably Borland C++ and DigitalMars, don't correctly
    convert operator?: operands to the same type and fail with compilation
    error instead. This can be worked around by explicitly casting to const
    wxChar*: wxLogError(_("error: %s"), !err.empty() ? (const wxChar*)err.c_str() : "")

- wxCtime() and wxAsctime() return char*; this is incompatible with Unicode
  build in wxWidgets 2.8 that returned wchar_t*.

- DigitalMars compiler has a bug that prevents it from using
  wxUniChar::operator bool in conditions and it erroneously reports type
  conversion ambiguity in expressions such as this:
     for ( wxString::const_iterator p = s.begin(); *p; ++p )
  This can be worked around by explicitly casting to bool:
     for ( wxString::const_iterator p = s.begin(); (bool)*p; ++p )

- Virtual wxHtmlParser::AddText() takes wxString, not wxChar*, argument now.

- Functions that took wxChar* arguments that could by NULL in wxWidgets 2.8
  are deprecated and passing NULL to them won't compile anymore, wxEmptyString
  must be used instead.

- wxTmemxxx() functions take either wxChar* or char*, not void*: use memxxx()
  with void pointers.

- Removed insecure wxGets() and wxTmpnam() functions.

- Removed global GetLine() function from wx/protocol/protocol.h, use
  wxProtocol::ReadLine() instead.

- wxVariant no longer derives from wxObject. wxVariantData also no longer
  derives from wxObject; instead of using wxDynamicCast with wxVariantData you
  can use the macro wxDynamicCastVariantData with the same arguments.

- wxWindow::Next/PrevControlId() don't exist any more as they couldn't be
  implemented correctly any longer because automatically generated ids are not
  necessarily allocated consecutively now. Use GetChildren() to find the
  next/previous control sibling instead.

- Calling wxConfig::Write() with an enum value will fail to compile because
  wxConfig now tries to convert all unknown types to wxString automatically.
  The simplest solution is to cast the enum value to int.

- Several wxImage methods which previously had "long bitmaptype" parameters
  have been changed to accept "wxBitmapType bitmaptype", please use enum
  wxBitmapType in your code.

- wxGridCellEditor::EndEdit() signature has changed and it was split in two
  functions, one still called EndEdit() and ApplyEdit(). See the documentation
  of the new functions for more details about how grid editors should be
  written now.

- wxEVT_GRID_CELL_CHANGE event renamed to wxEVT_GRID_CELL_CHANGED and shouldn't
  be vetoed any more, use the new wxEVT_GRID_CELL_CHANGING event to do it.

- wxListCtrlCompare function used with wxListCtrl::SortItems() must now declare
  its third parameter as wxIntPtr and not long (this allows passing pointers
  to it under 64 bit platforms too).

- Global wxPendingEvents and wxPendingEventsLocker objects were removed.
  You may use wxEventLoopBase::SuspendProcessingOfPendingEvents instead of
  locking wxPendingEventsLocker now.

- wxBitmapButton::GetBitmapXXX() overloads returning non-const wxBitmap
  references have been removed, modifying the returned bitmaps never worked and
  now results in compile-time error.


Deprecated methods and their replacements
-----------------------------------------

- wxCreateGreyedImage() deprecated, use wxImage::ConvertToGreyscale() instead.
- wxString::GetWriteBuf() and UngetWriteBuf() deprecated, using wxStringBuffer
  or wxStringBufferLength instead.
- wxDIRCTRL_SHOW_FILTERS style is deprecated, filters are alwsys shown if
  specified so this style should simply be removed
- wxDocManager::MakeDefaultName() replaced by MakeNewDocumentName() and
  wxDocument::GetPrintableName() with GetUserReadableName() which are simpler
  to use
- wxXmlProperty class was renamed to wxXmlAttribute in order to use standard
  terminology. Corresponding wxXmlNode methods were renamed to use
  "Attribute" instead of "Property" or "Prop" in their names.
- wxConnection::OnExecute() is not formally deprecated yet but new code should
  use simpler OnExec() version which is called with wxString argument
- Various wxMenuItem methods were deprecated in favour of more consisently
  named new versions:
    . GetLabel() is now GetItemLabelText()
    . GetText() is not GetItemLabel()
    . GetLabelFromText() is now GetLabelText()
    . SetText() is now SetItemLabel()
- wxBrush's, wxPen's SetStyle() and GetStyle() as well as the wxBrush/wxPen
  ctor now take respectively a wxBrushStyle and a wxPenStyle value instead of a
  plain "int style"; use the new wxBrush/wxPen style names (wxBRUSHSTYLE_XXX
  and wxPENSTYLE_XXX) instead of the old deprecated wxXXX styles.
- EVT_GRID_CELL_CHANGE was deprecated, use EVT_GRID_CELL_CHANGED instead if you
  don't veto the event in its handler and EVT_GRID_CELL_CHANGING if you do.
- EVT_CALENDAR_DAY event has been deprecated, use EVT_CALENDAR_SEL_CHANGED.
- EVT_CALENDAR_MONTH and EVT_CALENDAR_YEAR events are deprecated,
  use EVT_CALENDAR_PAGE_CHANGED which replaces both of them.
- wxCalendarCtrl::EnableYearChange() and wxCAL_NO_YEAR_CHANGE are deprecated.
  There is no replacement for this functionality, it is being dropped as it is
  not available in native wxCalendarCtrl implementations.
- wxDC::SetClippingRegion(const wxRegion&) overload is deprecated as it used
  different convention from the other SetClippingRegion() overloads: wxRegion
  passed to it was interpreted in physical, not logical, coordinates. Replace
  it with SetDeviceClippingRegion() if this was the correct thing to do in your
  code.
- wxTE_AUTO_SCROLL style is deprecated as it's always on by default anyhow.
- wxThreadHelper::Create() has been renamed to CreateThread which has a better
  name for a mix-in class, and allows setting the thread type.
- wxDos2UnixFilename, wxUnix2DosFilename, wxStripExtension, wxGetTempFileName,
  wxExpandPath, wxContractPath, wxRealPath, wxCopyAbsolutePath, wxSplitPath
  were deprecated in favour of wxFileName methods. See docs for more info.
- wxEvtHandler::TryValidator/Parent() are deprecated, override the new and
  documented TryBefore/After() methods if you used to override these ones.
- wxGetMultipleChoices() is deprecated, use wxGetSelectedChoices() which has
  the same signature but returns -1 and not 0 if the dialog was cancelled.
- building the windows which are placed inside wxStaticBoxes as siblings of the
  wxStaticBox is still allowed but it's deprecated as it gives some problems
  on some ports (e.g. wxGTK).
  You should now create windows placed inside a wxStaticBox as children of
  the static box itself.
- wxMouseState::{Left,Middle,Right}Down() were renamed to XXXIsDown() for
  consistency with wxMouseEvent and the old names were deprecated.


Major new features in this release
----------------------------------

- wxWidgets is now always built with Unicode support but provides the same
  simple (i.e. "char *"-tolerant) API as was available in ANSI build in the
  past.

- wxWidgets may now use either wchar_t (UTF-16/32) or UTF-8 internally,
  depending on what is optimal for the target platform.

- New propgrid library containing wxPropertyGrid and related classes.

- Many enhancements to wxDataViewCtrl.

- Event loops, timers and sockets can now be used in wxBase, without GUI.

- Events can now be connected to any functor, not necessarily a method of
  wxEvtHandler-derived class. The compile-time safety was also improved.

- Documentation for wxWidgets has been converted from LaTex to C++ headers
  with Doxygen comments and significantly improved in the process (screenshots
  of various controls were added, more identifiers are now linked to their
  definition &c). Any reports about inaccuracies in the documentation are
  welcome (and due to using the simple Doxygen syntax it is now easier than
  ever to submit patches correcting them! :-)

- Support for persistent objects automatically saving and restoring their state
  was added.


2.9.1:
------

All:

- Added wxStd{Input,Output}Stream classes (Jonathan Liu).
- Include port number in host header in wxHTTP (Marcin 'Malcom' Malich).
- Added wxTempFile::Flush().
- Added support for wxLongLong and wxULongLong in wxVariant.

All (GUI):

- Added support for showing bitmaps in wxButton.
- wxWindow::SetAutoLayout() now works for all windows, not just panels.