## Changes since 2.4.x

Listed here are the deprecated and incompatible changes made to wxWidgets.

For other changes (such as additional features, bug fixes, etc.) see the changes.txt file located in the docs directory of your wxWidgets directory.

Incompatible changes since 2.4.x
Deprecated changes since 2.4.x

### Incompatible changes since 2.4.x

wxEvent and its derivatives losing public variable members

wxEvent and its derivatives do not have their public variable members public any more. Please use Get/Set accessors.

New window repainting behaviour

Windows are no longer fully repainted when resized; use the new style wxFULL_REPAINT_ON_RESIZE to force this (wxNO_FULL_REPAINT_ON_RESIZE still exists but doesn't do anything any more, this behaviour is default now).

Window class member changes

wxWindow::m_font and m_backgroundColour/m_foregroundColour are no longer always set, use GetFont(), GetBack/ForegroundColour() to access them, and they will be dynamically determined if necessary.

Sizers Internal Overhaul

The sizers have had some fundamental internal changes in the 2.5.2 and 2.5.3 releases intended to make them do more of the "Right Thing" but also be as backwards compatible as possible. First a bit about how things used to work:

- The size that a window had when Add()ed to the sizer was assumed to be its minimal size, and that size would always be used by default when calculating layout size and positions, and the sizer itself would keep track of that minimal size.
- If the window item was Add()ed with the wxADJUST_MINSIZE flag then when layout was calculated the item's GetBestSize would be used to reset the minimal size that the sizer used.

The main thrust of the new sizer changes was to make behaviour like wxADJUST_MINSIZE be the default, and also to push the tracking of the minimal size to the window itself (since it knows its own needs) instead of having the sizer take care of it. Consequently these changes were made:

- The wxFIXED_MINSIZE flag was added to allow for the old behaviour. When this flag is used the size a window has when Add()ed to the sizer will be treated as its minimal size and it will not be readjusted on each layout.
- The minimum size stored in wxWindow and settable with SetSizeHints or SetMinSize will by default be used by the sizer (if it was set) as the minimal size of the sizer item. If the minsize was not set (or was only partially set) then the window's best size is fetched and it is used instead of (or blended with) the minsize. wxWindow::GetBestFittingSize was added to facilitate getting the size to be used by the sizers.
- The best size of a window is cached so it doesn't need to be recalculated on every layout. wxWindow::InvalidateBestSize was added and should be called (usually just internally in control methods) whenever something is done that would make the best size change.
- All wxControls were changed to set the minsize to what is passed to the constructor or their Create method, and also to set the real size of the control to the blending of the minsize and bestsize. wxWindow::SetBestFittingSize was added to help with this, although most controls don't need to call it directly because it is called indirectly via the SetInitialBestSize called in the base classes.

At this time, the only situation known not to work the same as before is the following:

    win = new SomeWidget(parent);
    win->SetSize(SomeNonDefaultSize);
    sizer->Add(win);

In this case the old code would have used the new size as the minimum, but now the sizer will use the default size as the minimum rather than the size set later. It is an easy fix though, just move the specification of the size to the constructor (assuming that SomeWidget will set its minsize there like the rest of the controls do) or call SetMinSize instead of SetSize.

In order to fit well with this new scheme of things, all wxControls or custom controls should do the following things. (Depending on how they are used you may also want to do the same thing for non-control custom windows.)

- Either override or inherit a meaningful DoGetBestSize method that calculates whatever size is "best" for the control. Once that size is calculated then there should normally be a call to CacheBestSize to save it for later use, unless for some reason you want the best size to be recalculated on every layout.
- Any method that changes the attributes of the control such that the best size will change should call InvalidateBestSize so it will be recalculated the next time it is needed.
- The control's constructor and/or Create method should ensure that the minsize is set to the size passed in, and that the control is sized to a blending of the min size and best size. This can be done by calling SetBestFittingSize.

Massive wxURL Rewrite

wxURL has undergone some radical changes.

- Many accessors of wxURL - GetHostName, GetProtocolName, and GetPath, have been replaced by its parent's (wxURI) counterparts - GetServer, GetScheme, and GetPath, respectively.
- ConvertToValidURI has been replaced by wxURI. Do not use ConvertToValidURI for future applications.
- ConvertFromURI has been replaced by wxURI::Unescape.

Minor incompatible changes since 2.4.x

- no initialization/cleanup can be done in wxApp's constructor or destructor because they are now called much earlier/later than before; please move any exiting code from there to wxApp::OnInit()/OnExit()
- also, OnExit() is not called if OnInit() fails
- finally the program exit code is OnRun() return value, not OnExit() one
- `wxTheApp` can't be assigned to any longer, use wxApp::SetInstance() instead
- wxFileType::GetIcon() returns wxIconLocation, not wxIcon
- wxColourDatabase is not a wxList any more, use AddColour to add new colours
- wxWindow::Clear() is now called ClearBackground()
- pointer returned by wxFont::GetNativeFontInfo() must not be deleted now
- wxMouseEvent::Moving() doesn't return true if mouse is being dragged any more
- (most) controls now inherit parents colours by default, override ShouldInheritColours() to return false if you don't want this to happen
- wxApp::SendIdleEvents() now takes 2 arguments
- wxTabView::GetLayers() changed return type from wxList& to wxTabLayerList& (when WXWIN_COMPATIBILITY_2_4 == 0)
- wxID_SEPARATOR (id used for the menu separators) value changed from -1 to -2
- wxGetNumberFromUser() is now in separate wx/numdlg.h, not wx/textdlg.h
- wxChoice and wxCombobox now handle their size in the same way as in all the other ports under MSW, new code is actually correct but different from weird stuff they were doing before so the behaviour of your programs might change
- wxTaskBarIcon objects must now be destroyed before the application can exit. Previously, the application terminated if there were no top level windows; now it terminates if there are no top level windows or taskbar icons left.
- wxZlibInputStream is not by default compatible with the output of the 2.4.x version of wxZlibOutputStream. However, there is a compatibility mode, switched on by passing wxZLIB_24COMPATIBLE to the constructor.
- when WXWIN_COMPATIBILITY_2_4 == 0 wxHashTable uses a new implementation not using wxList keyed interface (the same used when wxUSE_STL == 1), the only incompatibility being that Next() returns a wxHashTable::Node* instead of a wxNode*.
- non-const wxDC methods GetBackground(), GetBrush(), GetFont() and GetPen() as well as wxWindow methods GetFont() and GetCursor() don't exist any more, please fix your code -- it never worked correctly anyhow if you modified the objects returned by these methods so you should simply switch to using const methods.
- wxWindow::GetFont() now returns wxFont object instead of reference
- EVT_XXX macros are now type-safe; code that uses wrong type for event handler's argument will no longer compile.
- Identical functionality of wxFileDialog::ParseWildcard, wxGenericDirCtrl::ParseFilter, Motif and MSW parsing native dialogs is now accessible in ::wxParseCommonDialogsFilter
- wxNotebookSizer and wxBookCtrlSizer are now deprecated -- they are no longer needed, you can treat wxNotebook as any other control and put it directly into the sizer that was wxNotebookSizer's parent sizer in old code.
- wxFile methods now return either wxFileOffset or wxFileSize_t which may be a 64 bit integer type, even on 32 bit platforms, instead of off_t and so the return value of wxFile::Length(), for example, shouldn't be assigned to off_t variable any more (the compiler might warn you about this)
- wxListItem::m_data is now of type wxUIntPtr, not long, for compatibility with 64 bit systems
- wxSizer::Add/Insert returns pointer to wxSizerItem just added so conditions writeen with if(Add(..)==true) will not work. Use if(Add(..)) instead.
- New wxBrush::IsHatch() checking for brush type replaces IS_HATCH macro.
- wxSystemSettings::GetSystem*() members deprecated and replaced with wxSystemSettings::Get*().

### Deprecated changes since 2.4.x

- wxURL::GetInputStream() and similar functionality has been deprecated in favor of other ways of connecting, such as though sockets or wxFileSystem.
- wxDocManager::GetNoHistoryFiles() renamed to GetHistoryFilesCount()
- wxSizer::Remove(wxWindow *), use Detach() instead (it is more clear)
- wxSizer::Set/GetOption(): use Set/GetProportion() instead
- wxKeyEvent::KeyCode(): use GetKeyCode instead
- wxList::Number, First, Last, Nth: use GetCount, GetFirst/Last, Item instead
- wxNode::Next, Previous, Data: use GetNext, GetPrevious, GetData instead
- wxListBase::operator wxList&(): use typesafe lists instead
- wxTheFontMapper: use wxFontMapper::Get() instead
- wxStringHashTable: use wxHashMap instead
- wxHashTableLong: use wxHashMap instead
- wxArrayString::GetStringArray: use wxCArrayString or alternative wxWidgets methods taking wxArrayString
- wxArrayString::Remove(index, count): use RemoveAt instead
- wxTreeItemId conversion to long is deprecated and shouldn't be used
- wxTreeCtrl::GetFirst/NextChild() 2nd argument now has type wxTreeItemIdValue and not long, please change declarations of "cookie"s in your code accordingly -- otherwise your code won't work on 64 bit platforms
- (MSW only) wxWindow::GetUseCtl3D(), GetTransparentBackground() and SetTransparent() as well as wxNO_3D and wxUSER_COLOURS styles
- wxList keyed interface: use wxHashMap instead
- wxColourDatabase::FindColour(): use Find() instead (NOTE: it has a different return type)
- wxHashTable::Next: use wxHashTable::Node* or wxHashTable::compatibility_iterator to store the return value
- wxWave class; use wxSound instead
- The wxHIDE_READONLY flag for wxFileDialog was not implemented and has now been removed
- wxTaskBarIcon::OnXXX() virtual methods: use events instead
- obsolete and not used wxUSE_GENERIC_DIALOGS_IN_MSW has been removed
- wxDbTable::wxDbTable with wxChar* deprecated, same with wxString& instead.