Secondly, wxWidgets uses, although only rarely currently, wxMemoryBuffer
for dealing with raw buffers in memory.
- @li @ref overview_bufferclasses_wxcb
+ @li @ref overview_bufferclasses_xcb
<hr>
- @section overview_bufferclasses_wxcb wxXCharBuffer Overview
+ @section overview_bufferclasses_xcb wxXCharBuffer Overview
+
+ @subsection overview_bufferclasses_xcb_general General Usage
- @b General Usage
As mentioned, wxCharBuffer and its wide character variant wxWCharBuffer deal
with c strings in memory. They have two constructors, one in which you pass
the c string you want them to have a copy of, and another where you specify
can be used safely to c functions with variable arguments such as printf.
They also contain standard assignment, character access operators and a copy constructor.
- @b Destruction
+ @subsection overview_bufferclasses_xcb_destruct Destruction
+
It should be noted that on destruction wxCharBuffer and its wide character
variant delete the c string that hold onto. If you want to get the pointer
to the buffer and don't want wxCharBuffer to delete it on destruction,
/////////////////////////////////////////////////////////////////////////////
-// Name: envvars
+// Name: envvars.h
// Purpose: topic overview
// Author: wxWidgets team
// RCS-ID: $Id$
/*!
- @page envvars_overview Environment variables
+ @page overview_envvars Environment variables
This section describes all environment variables that affect execution of
wxWidgets programs.
-
-
-
-
- @c WXTRACE
-
-
-
-
- (Debug build only.)
- This variable can be set to a comma-separated list of trace masks used in
- #wxLogTrace calls;
- wxLog::AddTraceMask is called for every mask
- in the list during wxWidgets initialization.
-
-
-
-
-
- @c WXPREFIX
-
-
-
-
- (Unix only.)
- Overrides installation prefix. Normally, the prefix
- is hard-coded and is the same as the value passed to @c configure via
- the @c --prefix switch when compiling the library (typically
- @c /usr/local or @c /usr). You can set WXPREFIX if you are for example
- distributing a binary version of an application and you don't know in advance
- where it will be installed.
-
-
-
-
-
- @c WXMODE
-
-
-
-
- (wxMGL only.)
- Sets MGL video mode. The value must be in form
- @e widthx@e height-@e depth. The default is @c 640x480-16.
-
-
-
-
-
- @c WXSTDERR
-
-
-
-
- (wxMGL only.)
- Redirects stderr output to a file.
-
- */
-
+ @beginDefList
+ @itemdef{WXTRACE,
+ (Debug build only.)
+ This variable can be set to a comma-separated list of trace masks used in
+ #wxLogTrace calls; wxLog::AddTraceMask is called for every mask
+ in the list during wxWidgets initialization.}
+ @itemdef{WXPREFIX,
+ (Unix only.)
+ Overrides installation prefix. Normally, the prefix
+ is hard-coded and is the same as the value passed to @c configure via
+ the @c --prefix switch when compiling the library (typically
+ @c /usr/local or @c /usr). You can set WXPREFIX if you are for example
+ distributing a binary version of an application and you don't know in advance
+ where it will be installed.}
+ @itemdef{WXMODE,
+ (wxMGL only.)
+ Sets MGL video mode. The value must be in form
+ @e widthx@e height-@e depth. The default is @c 640x480-16.}
+ @itemdef{WXSTDERR,
+ (wxMGL only.)
+ Redirects stderr output to a file.}
+
+*/
/////////////////////////////////////////////////////////////////////////////
-// Name: eventhandling
+// Name: eventhandling.h
// Purpose: topic overview
// Author: wxWidgets team
// RCS-ID: $Id$
/*!
- @page eventhandling_overview Event handling overview
+ @page overview_eventhandling Event handling overview
Classes: #wxEvtHandler, #wxWindow, #wxEvent
- #Introduction
- @ref eventprocessing_overview
- @ref progevent_overview
- @ref pluggablehandlers_overview
- @ref windowids_overview
- @ref eventmacros_overview
- @ref customevents_overview
+ @li @ref overview_eventhandling_introduction
+ @li @ref overview_eventhandling_processing
+ @li @ref overview_eventhandling_prog
+ @li @ref overview_eventhandling_pluggable
+ @li @ref overview_eventhandling_winid
+ <!-- @li @ref overview_eventhandling_macros -->
+ @li @ref overview_eventhandling_pluggable
+ @li @ref overview_eventhandling_winid
- @section eventintroduction Introduction
+
+ <hr>
+
+
+ @section overview_eventhandling_introduction Introduction
Before version 2.0 of wxWidgets, events were handled by the application
either by supplying callback functions, or by overriding virtual member
functions such as @b OnSize.
+
From wxWidgets 2.0, @e event tables are used instead, with a few exceptions.
An event table is placed in an implementation file to tell wxWidgets how to map
events to member functions. These member functions are not virtual functions, but
- they are all similar in form: they take a single wxEvent-derived argument, and have a void return
- type.
+ they are all similar in form: they take a single wxEvent-derived argument,
+ and have a void return type.
Here's an example of an event table.
@code
The first two entries map menu commands to two different member functions. The
EVT_SIZE macro doesn't need a window identifier, since normally you are only
interested in the current window's size events.
+
The EVT_BUTTON macro demonstrates that the originating event does not have to
come from the window class implementing the event table -- if the event source
is a button within a panel within a frame, this will still work, because event
tables are searched up through the hierarchy of windows for the command events.
In this case, the button's event table will be searched, then the parent
panel's, then the frame's.
+
As mentioned before, the member functions that handle events do not have to be
virtual. Indeed, the member functions should not be virtual as the event
handler ignores that the functions are virtual, i.e. overriding a virtual
member function in a derived class will not have any effect. These member
functions take an event argument, and the class of event differs according to
the type of event and the class of the originating window. For size events,
- #wxSizeEvent is used. For menu commands and most
- control commands (such as button presses),
- #wxCommandEvent is used. When controls get more
- complicated, then specific event classes are used, such as
- #wxTreeEvent for events from
- #wxTreeCtrl windows.
+ #wxSizeEvent is used. For menu commands and most control commands
+ (such as button presses), #wxCommandEvent is used. When controls get more
+ complicated, then specific event classes are used, such as #wxTreeEvent for
+ events from #wxTreeCtrl windows.
+
As well as the event table in the implementation file, there must also be a
DECLARE_EVENT_TABLE macro somewhere in the class declaration. For example:
or private) but that it is probably better to insert it at the end, as shown,
because this macro implicitly changes the access to protected which may be
quite unexpected if there is anything following it.
+
Finally, if you don't like using macros for static initialization of the event
tables you may also use wxEvtHandler::Connect to
connect the events to the handlers dynamically, during run-time. See the
@ref sampleevent_overview for an example of doing it.
- @section eventprocessing How events are processed
+
+ @section overview_eventhandling_processing How events are processed
When an event is received from the windowing system, wxWidgets calls
wxEvtHandler::ProcessEvent on the first
event handler object belonging to the window generating the event.
+
It may be noted that wxWidgets' event processing system implements something
very close to virtual methods in normal C++, i.e. it is possible to alter
the behaviour of a class by overriding its event handling functions. In
many cases this works even for changing the behaviour of native controls.
+
For example it is possible to filter out a number of key events sent by the
system to a native text control by overriding wxTextCtrl and defining a
handler for key events using EVT_KEY_DOWN. This would indeed prevent
any key events from being sent to the native control - which might not be
what is desired. In this case the event handler function has to call Skip()
so as to indicate that the search for the event handler should continue.
+
To summarize, instead of explicitly calling the base class version as you
would have done with C++ virtual functions (i.e. @e wxTextCtrl::OnChar()),
you should instead call #Skip.
+
In practice, this would look like this if the derived text control only
accepts 'a' to 'z' and 'A' to 'Z':
}
@endcode
-
The normal order of event table searching by ProcessEvent is as follows:
-
- If the object is disabled (via a call to wxEvtHandler::SetEvtHandlerEnabled)
- the function skips to step (6).
- If the object is a wxWindow, @b ProcessEvent is recursively called on the window's
- #wxValidator. If this returns @true, the function exits.
- @b SearchEventTable is called for this event handler. If this fails, the base
- class table is tried, and so on until no more tables exist or an appropriate function was found,
- in which case the function exits.
- The search is applied down the entire chain of event handlers (usually the chain has a length
- of one). If this succeeds, the function exits.
- If the object is a wxWindow and the event is set to set to propagate (in the library only
- wxCommandEvent based events are set to propagate), @b ProcessEvent is recursively applied
- to the parent window's event handler. If this returns @true, the function exits.
- Finally, @b ProcessEvent is called on the wxApp object.
-
-
- @b Pay close attention to Step 5. People often overlook or get
+ @li If the object is disabled (via a call to wxEvtHandler::SetEvtHandlerEnabled)
+ the function skips to step (6).
+ @li If the object is a wxWindow, @b ProcessEvent is recursively called on the window's
+ #wxValidator. If this returns @true, the function exits.
+ @li @b SearchEventTable is called for this event handler. If this fails, the base
+ class table is tried, and so on until no more tables exist or an appropriate
+ function was found, in which case the function exits.
+ @li The search is applied down the entire chain of event handlers (usually the chain has
+ a length of one). If this succeeds, the function exits.
+ @li If the object is a wxWindow and the event is set to set to propagate (in the library only
+ wxCommandEvent based events are set to propagate), @b ProcessEvent is recursively applied
+ to the parent window's event handler. If this returns @true, the function exits.
+ @li Finally, @b ProcessEvent is called on the wxApp object.
+
+ <b>Pay close attention to Step 5</b>. People often overlook or get
confused by this powerful feature of the wxWidgets event processing
system. To put it a different way, events set to propagate
- (@ref eventshouldpropagate_overview)
+ (see @ref overview_eventhandling_propagate)
(most likely derived either directly or indirectly from wxCommandEvent)
will travel up the containment hierarchy from child to parent until the
maximal propagation level is reached or an event handler is found that
- doesn't call #event.Skip().
+ doesn't call @c event.Skip().
+
Finally, there is another additional complication (which, in fact, simplifies
life of wxWidgets programmers significantly): when propagating the command
events upwards to the parent window, the event propagation stops when it
may be very difficult, if not impossible, to track down all the dialogs which
may be popped up in a complex program (remember that some are created
automatically by wxWidgets). If you need to specify a different behaviour for
- some reason, you can use
- #SetExtraStyle(wxWS_EX_BLOCK_EVENTS)
+ some reason, you can use #SetExtraStyle(wxWS_EX_BLOCK_EVENTS)
explicitly to prevent the events from being propagated beyond the given window
or unset this flag for the dialogs which have it on by default.
+
Typically events that deal with a window as a window (size, motion,
paint, mouse, keyboard, etc.) are sent only to the window. Events
that have a higher level of meaning and/or are generated by the window
itself, (button click, menu select, tree expand, etc.) are command
- events and are sent up to the parent to see if it is interested in the
- event.
+ events and are sent up to the parent to see if it is interested in the event.
+
Note that your application may wish to override ProcessEvent to redirect processing of
events. This is done in the document/view framework, for example, to allow event handlers
to be defined in the document or view. To test for command events (which will probably
- be the only events you wish to redirect), you may use
- wxEvent::IsCommandEvent for efficiency,
+ be the only events you wish to redirect), you may use wxEvent::IsCommandEvent for efficiency,
instead of using the slower run-time type system.
+
As mentioned above, only command events are recursively applied to the parents event
handler in the library itself. As this quite often causes confusion for users,
here is a list of system events which will NOT get sent to the parent's event handler:
-
-
-
-
-
- #wxEvent
-
-
-
-
- The event base class
-
-
-
-
-
- #wxActivateEvent
-
-
-
-
- A window or application activation event
-
-
-
-
-
- #wxCloseEvent
-
-
-
-
- A close window or end session event
-
-
-
-
-
- #wxEraseEvent
-
-
-
-
- An erase background event
-
-
-
-
-
- #wxFocusEvent
-
-
-
-
- A window focus event
-
-
-
-
-
- #wxKeyEvent
-
-
-
-
- A keypress event
-
-
-
-
-
- #wxIdleEvent
-
-
-
-
- An idle event
-
-
-
-
-
- #wxInitDialogEvent
-
-
-
-
- A dialog initialisation event
-
-
-
-
-
- #wxJoystickEvent
-
-
-
-
- A joystick event
-
-
-
-
-
- #wxMenuEvent
-
-
-
-
- A menu event
-
-
-
-
-
- #wxMouseEvent
-
-
-
-
- A mouse event
-
-
-
-
-
- #wxMoveEvent
-
-
-
-
- A move event
-
-
-
-
-
- #wxPaintEvent
-
-
-
-
- A paint event
-
-
-
-
-
- #wxQueryLayoutInfoEvent
-
-
-
-
- Used to query layout information
-
-
-
-
-
- #wxSetCursorEvent
-
-
-
-
- Used for special cursor processing based on current mouse position
-
-
-
-
-
- #wxSizeEvent
-
-
-
-
- A size event
-
-
-
-
-
- #wxScrollWinEvent
-
-
-
-
- A scroll event sent by a scrolled window (not a scroll bar)
-
-
-
-
-
- #wxSysColourChangedEvent
-
-
-
-
- A system colour change event
-
-
-
-
+ @li #wxEvent: The event base class
+ @li #wxActivateEvent: A window or application activation event
+ @li #wxCloseEvent: A close window or end session event
+ @li #wxEraseEvent: An erase background event
+ @li #wxFocusEvent: A window focus event
+ @li #wxKeyEvent: A keypress event
+ @li #wxIdleEvent: An idle event
+ @li #wxInitDialogEvent: A dialog initialisation event
+ @li #wxJoystickEvent: A joystick event
+ @li #wxMenuEvent: A menu event
+ @li #wxMouseEvent: A mouse event
+ @li #wxMoveEvent: A move event
+ @li #wxPaintEvent: A paint event
+ @li #wxQueryLayoutInfoEvent: Used to query layout information
+ @li #wxSetCursorEvent: Used for special cursor processing based on current mouse position
+ @li #wxSizeEvent: A size event
+ @li #wxScrollWinEvent: A scroll event sent by a scrolled window (not a scroll bar)
+ @li #wxSysColourChangedEvent: A system colour change event
In some cases, it might be desired by the programmer to get a certain number
of system events in a parent window, for example all key events sent to, but not
all events (or any selection of them) to the parent window.
- @section progevent Events generated by the user vs programmatically generated events
+ @section overview_eventhandling_prog Events generated by the user vs programmatically generated events
While generically #wxEvents can be generated both by user
actions (e.g. resize of a #wxWindow) and by calls to functions
- (e.g. wxWindow::SetSize), wxWidgets controls
- normally send #wxCommandEvent-derived events only for
- the user-generated events. The only @b exceptions to this rule are:
-
-
-
-
-
-
- wxNotebook::AddPage
-
-
-
-
- No event-free alternatives
-
-
-
-
-
- wxNotebook::AdvanceSelection
-
-
-
-
- No event-free alternatives
-
-
-
-
-
- wxNotebook::DeletePage
-
-
-
-
- No event-free alternatives
-
-
-
-
-
- wxNotebook::SetSelection
-
-
-
-
- Use wxNotebook::ChangeSelection instead, as wxNotebook::SetSelection is deprecated
-
-
-
-
-
- wxTreeCtrl::Delete
-
-
-
-
- No event-free alternatives
-
-
-
-
-
- wxTreeCtrl::DeleteAllItems
-
-
-
-
- No event-free alternatives
-
-
-
-
-
- wxTreeCtrl::EditLabel
-
-
-
+ (e.g. wxWindow::SetSize), wxWidgets controls normally send #wxCommandEvent-derived
+ events only for the user-generated events. The only @b exceptions to this rule are:
- No event-free alternatives
+ @li wxNotebook::AddPage: No event-free alternatives
+ @li wxNotebook::AdvanceSelection: No event-free alternatives
+ @li wxNotebook::DeletePage: No event-free alternatives
+ @li wxNotebook::SetSelection: Use wxNotebook::ChangeSelection instead, as
+ wxNotebook::SetSelection is deprecated
+ @li wxTreeCtrl::Delete: No event-free alternatives
+ @li wxTreeCtrl::DeleteAllItems: No event-free alternatives
+ @li wxTreeCtrl::EditLabel: No event-free alternatives
+ @li All #wxTextCtrl methods
+ wxTextCtrl::ChangeValue can be used instead of wxTextCtrl::SetValue but the other
+ functions, such as #Replace or #WriteText don't have event-free equivalents.
-
- All #wxTextCtrl methods
-
-
-
-
- wxTextCtrl::ChangeValue can be used instead
- of wxTextCtrl::SetValue but the other functions,
- such as #Replace or #WriteText
- don't have event-free equivalents
-
-
-
-
-
-
-
- @section pluggablehandlers Pluggable event handlers
+ @section overview_eventhandling_pluggable Pluggable event handlers
In fact, you don't have to derive a new class from a window class
if you don't want to. You can derive a new class from wxEvtHandler instead,
- defining the appropriate event table, and then call
- wxWindow::SetEventHandler (or, preferably,
- wxWindow::PushEventHandler) to make this
+ defining the appropriate event table, and then call wxWindow::SetEventHandler
+ (or, preferably, wxWindow::PushEventHandler) to make this
event handler the object that responds to events. This way, you can avoid
a lot of class derivation, and use instances of the same event handler class (but different
objects as the same event handler object shouldn't be used more than once) to
- handle events from instances of different widget classes. If you ever have to call a window's event handler
+ handle events from instances of different widget classes.
+
+ If you ever have to call a window's event handler
manually, use the GetEventHandler function to retrieve the window's event handler and use that
to call the member function. By default, GetEventHandler returns a pointer to the window itself
unless an application has redirected event handling using SetEventHandler or PushEventHandler.
+
One use of PushEventHandler is to temporarily or permanently change the
behaviour of the GUI. For example, you might want to invoke a dialog editor
in your application that changes aspects of dialog boxes. You can
to form a chain of event handlers, where each handler processes a different
range of events independently from the other handlers.
- @section windowids Window identifiers
+
+
+ @section overview_eventhandling_winid Window identifiers
Window identifiers are integers, and are used to
uniquely determine window identity in the event system (though you can use it
particular context you're interested in, such as a frame and its children. You
may use the @c wxID_OK identifier, for example, on any number of dialogs so
long as you don't have several within the same dialog.
+
If you pass @c wxID_ANY to a window constructor, an identifier will be
generated for you automatically by wxWidgets. This is useful when you don't
care about the exact identifier either because you're not going to process the
as well. The automatically generated identifiers are always negative and so
will never conflict with the user-specified identifiers which must be always
positive.
+
The following standard identifiers are supplied. You can use wxID_HIGHEST to
determine the number above which it is safe to define your own identifiers. Or,
you can use identifiers below wxID_LOWEST.
@endcode
- @section eventmacros Event macros summary
+
+ <!--
+
+ NOTE: this list is incomplete and it's a trouble to maintain it!
+ we must find an automatic way to generate it
+
+
+ @section overview_eventhandling_macros Event macros summary
@b Macros listed by event class
The documentation for specific event macros is organised by event class. Please refer
toolbars and controls.
+ -->
+ @section overview_eventhandling_custom Custom event summary
- @section customevents Custom event summary
+ @subsection overview_eventhandling_custom_general General approach
- @b General approach
Since version 2.2.x of wxWidgets, each event type is identified by ID which
is given to the event type @e at runtime which makes it possible to add
new event types to the library or application without risking ID clashes
(two different event types mistakingly getting the same event ID). This
event type ID is stored in a struct of type @b const wxEventType.
+
In order to define a new event type, there are principally two choices.
One is to define a entirely new event class (typically deriving from
#wxEvent or #wxCommandEvent.
+
The other is to use the existing event classes and give them an new event
type. You'll have to define and declare a new event type using either way,
and this is done using the following macros:
applications where you have to give the event type ID an explicit value.
See also the @ref sampleevent_overview for an example of code
defining and working with the custom event types.
- @b Using existing event classes
+
+
+ @subsection overview_eventhandling_custom_existing Using existing event classes
+
If you just want to use a #wxCommandEvent with
a new event type, you can then use one of the generic event table macros
listed below, without having to define a new macro yourself. This also
@code
DECLARE_EVENT_TYPE(wxEVT_MY_EVENT, -1)
-
DEFINE_EVENT_TYPE(wxEVT_MY_EVENT)
// user code intercepting the event
@endcode
- @b Generic event table macros
-
-
-
-
-
-
- @b EVT_CUSTOM(event, id, func)
-
-
-
-
- Allows you to add a custom event table
- entry by specifying the event identifier (such as wxEVT_SIZE), the window identifier,
- and a member function to call.
-
-
-
-
-
- @b EVT_CUSTOM_RANGE(event, id1, id2, func)
-
-
+ @subsection overview_eventhandling_custom_generic Generic event table macros
+
+ @beginTable
+ @row2col{EVT_CUSTOM(event\, id\, func),
+ Allows you to add a custom event table
+ entry by specifying the event identifier (such as wxEVT_SIZE),
+ the window identifier, and a member function to call.}
+ @row2col{EVT_CUSTOM_RANGE(event\, id1\, id2\, func),
+ The same as EVT_CUSTOM, but responds to a range of window identifiers.}
+ @row2col{EVT_COMMAND(id\, event\, func),
+ The same as EVT_CUSTOM, but expects a member function with a
+ wxCommandEvent argument.}
+ @row2col{EVT_COMMAND_RANGE(id1\, id2\, event\, func),
+ The same as EVT_CUSTOM_RANGE, but
+ expects a member function with a wxCommandEvent argument.}
+ @row2col{EVT_NOTIFY(event\, id\, func),
+ The same as EVT_CUSTOM, but
+ expects a member function with a wxNotifyEvent argument.}
+ @row2col{EVT_NOTIFY_RANGE(event\, id1\, id2\, func),
+ The same as EVT_CUSTOM_RANGE, but
+ expects a member function with a wxNotifyEvent argument.}
+ @endTable
+
+
+ @subsection overview_eventhandling_custom_ownclass Defining your own event class
-
- The same as EVT_CUSTOM,
- but responds to a range of window identifiers.
-
-
-
-
-
- @b EVT_COMMAND(id, event, func)
-
-
-
-
- The same as EVT_CUSTOM, but
- expects a member function with a wxCommandEvent argument.
-
-
-
-
-
- @b EVT_COMMAND_RANGE(id1, id2, event, func)
-
-
-
-
- The same as EVT_CUSTOM_RANGE, but
- expects a member function with a wxCommandEvent argument.
-
-
-
-
-
- @b EVT_NOTIFY(event, id, func)
-
-
-
-
- The same as EVT_CUSTOM, but
- expects a member function with a wxNotifyEvent argument.
-
-
-
-
-
- @b EVT_NOTIFY_RANGE(event, id1, id2, func)
-
-
-
-
- The same as EVT_CUSTOM_RANGE, but
- expects a member function with a wxNotifyEvent argument.
-
-
-
-
-
-
- @b Defining your own event class
Under certain circumstances, it will be required to define your own event
class e.g. for sending more complex data from one place to another. Apart
from defining your event class, you will also need to define your own
}
@endcode
- */
-
+*/
/////////////////////////////////////////////////////////////////////////////
-// Name: exceptions
+// Name: exceptions.h
// Purpose: topic overview
// Author: wxWidgets team
// RCS-ID: $Id$
/*!
- @page exceptions_overview C++ exceptions overview
+ @page overview_exceptions C++ exceptions overview
- #Introduction
- @ref exceptionstrategies_overview
- #Technicalities
+ @li @ref overview_exceptions_introduction
+ @li @ref overview_exceptions_strategies
+ @li @ref overview_exceptions_tech
- @section exceptionintroduction Introduction
+ <hr>
+
+
+ @section overview_exceptions_introduction Introduction
wxWidgets had been started long before the exceptions were introduced in C++ so
it is not very surprising that it is not built around using them as some more
wxWidgets, even using the exceptions in the user code was dangerous because the
library code wasn't exception-safe and so an exception propagating through it
could result in memory and/or resource leaks, and also not very convenient.
+
Starting from the version 2.5.1 wxWidgets becomes more exception-friendly. It
still doesn't use the exceptions by itself but it should be now safe to use the
exceptions in the user code and the library tries to help you with this. Please
note that making the library exception-safe is still work in progress.
- @section exceptionstrategies Strategies for exceptions handling
+ @section overview_exceptions_strategies Strategies for exceptions handling
There are several choice for using the exceptions in wxWidgets programs. First
of all, you may not use them at all. As stated above, the library doesn't throw
any exceptions by itself and so you don't have to worry about exceptions at all
unless your own code throws them. This is, of course, the simplest solution but
may be not the best one to deal with all possible errors.
+
Another strategy is to use exceptions only to signal truly fatal errors. In
this case you probably don't expect to recover from them and the default
behaviour -- to simply terminate the program -- may be appropriate. If it is
event loop. To deal with the exceptions which may arise during the program
startup and/or shutdown you should insert try/catch clauses in
#OnInit() and/or #OnExit() as well.
+
Finally, you may also want to continue running even when certain exceptions
occur. If all of your exceptions may happen only in the event handlers of a
single class (or only in the classes derived from it), you may centralize your
all the exceptions thrown by any event handler.
- @section exceptionstechnicalities Technicalities
+ @section overview_exceptions_tech Technicalities
- To use any kind of exception support in the library you need to build it with
- @c wxUSE_EXCEPTIONS set to 1. This should be the case by default but
+ To use any kind of exception support in the library you need to build it
+ with @c wxUSE_EXCEPTIONS set to 1. This should be the case by default but
if it isn't, you should edit the @c include/wx/msw/setup.h file under
Windows or run @c configure with @c --enable-exceptions argument
under Unix.
+
On the other hand, if you do not plan to use exceptions, setting this
flag to 0 or using @c --disable-exceptions could result in a leaner and
slightly faster library.
- As for any other library feature, there is a #sample
- showing how to use it. Please look at its sources for further information.
-
- */
+ As for any other library feature, there is a sample (@c except)
+ showing how to use it. Please look at its sources for further information.
+*/
/////////////////////////////////////////////////////////////////////////////
-// Name: file
+// Name: file.h
// Purpose: topic overview
// Author: wxWidgets team
// RCS-ID: $Id$
/*!
- @page file_overview File classes and functions overview
+ @page overview_file File classes and functions overview
+
+ Classes: #wxFile, #wxDir, #wxTempFile, #wxTextFile
- Classes: #wxFile, #wxDir, #wxTempFile,
- #wxTextFile
Functions: see @ref filefunctions_overview.
+
wxWidgets provides some functions and classes to facilitate working with files.
As usual, the accent is put on cross-platform features which explains, for
example, the #wxTextFile class which may be used to convert
between different types of text files (DOS/Unix/Mac).
+
wxFile may be used for low-level IO. It contains all the usual functions to work
with files (opening/closing, reading/writing, seeking, and so on) but compared with
using standard C functions, has error checking (in case of an error a message
is logged using #wxLog facilities) and closes the file
automatically in the destructor which may be quite convenient.
+
wxTempFile is a very small file designed to make replacing the files contents
safer - see its #documentation for more details.
+
wxTextFile is a general purpose class for working with small text files on line
by line basis. It is especially well suited for working with configuration files
and program source files. It can be also used to work with files with "non
native" line termination characters and write them as "native" files if needed
(in fact, the files may be written in any format).
+
wxDir is a helper class for enumerating the files or subdirectories of a
directory. It may be used to enumerate all files, only files satisfying the
given template mask or only non-hidden files.
- */
-
+*/
/////////////////////////////////////////////////////////////////////////////
-// Name: fs
+// Name: filesystem.h
// Purpose: topic overview
// Author: wxWidgets team
// RCS-ID: $Id$
/*!
- @page fs_overview wxFileSystem
+ @page overview_fs wxFileSystem overview
The wxHTML library uses a @b virtual file systems mechanism
similar to the one used in Midnight Commander, Dos Navigator,
FAR or almost any modern file manager. It allows the user to access
data stored in archives as if they were ordinary files. On-the-fly
generated files that exist only in memory are also supported.
- @b Classes
+
+ @li @ref overview_fs_classes
+ @li @ref overview_fs_locations
+ @li @ref overview_fs_combined
+ @li @ref overview_fs_wxhtmlfs
+ @li @ref overview_fs_init
+
+
+ <hr>
+
+
+ @section overview_fs_classes Classes
+
Three classes are used in order to provide virtual file systems mechanism:
+ @li The #wxFSFile class provides information
+ about opened file (name, input stream, mime type and anchor).
+ @li The #wxFileSystem class is the interface.
+ Its main methods are ChangePathTo() and OpenFile(). This class
+ is most often used by the end user.
+ @li The #wxFileSystemHandler is the core
+ of virtual file systems mechanism. You can derive your own handler and pass
+ it to the VFS mechanism. You can derive your own handler and pass it to
+ wxFileSystem's AddHandler() method. In the new handler you only need to
+ override the OpenFile() and CanOpen() methods.
- The #wxFSFile class provides information
- about opened file (name, input stream, mime type and anchor).
- The #wxFileSystem class is the interface.
- Its main methods are ChangePathTo() and OpenFile(). This class
- is most often used by the end user.
- The #wxFileSystemHandler is the core
- of virtual file systems mechanism. You can derive your own handler and pass it to
- the VFS mechanism. You can derive your own handler and pass it to
- wxFileSystem's AddHandler() method. In the new handler you only need to
- override the OpenFile() and CanOpen() methods.
+ @section overview_fs_locations Locations
- @b Locations
Locations (aka filenames aka addresses) are constructed from four parts:
+ @li @b protocol - handler can recognize if it is able to open a
+ file by checking its protocol. Examples are "http", "file" or "ftp".
+ @li <b>right location</b> - is the name of file within the protocol.
+ In "http://www.wxwidgets.org/index.html" the right location is "//www.wxwidgets.org/index.html".
+ @li @b anchor - an anchor is optional and is usually not present.
+ In "index.htm#chapter2" the anchor is "chapter2".
+ @li <b>left location</b> - this is usually an empty string.
+ It is used by 'local' protocols such as ZIP.
+ See Combined Protocols paragraph for details.
- @b protocol - handler can recognize if it is able to open a
- file by checking its protocol. Examples are "http", "file" or "ftp".
- @b right location - is the name of file within the protocol.
- In "http://www.wxwidgets.org/index.html" the right location is "//www.wxwidgets.org/index.html".
- @b anchor - an anchor is optional and is usually not present.
- In "index.htm#chapter2" the anchor is "chapter2".
- @b left location - this is usually an empty string.
- It is used by 'local' protocols such as ZIP.
- See Combined Protocols paragraph for details.
+ @section overview_fs_combined Combined Protocols
- @b Combined Protocols
The left location precedes the protocol in the URL string.
+
It is not used by global protocols like HTTP but it becomes handy when nesting
protocols - for example you may want to access files in a ZIP archive:
file:archives/cpp_doc.zip#zip:reference/fopen.htm#syntax
In this example, the protocol is "zip", right location is
"reference/fopen.htm", anchor is "syntax" and left location
is "file:archives/cpp_doc.zip".
- There are @b two protocols used in this example: "zip" and "file".
- @b File Systems Included in wxHTML
- The following virtual file system handlers are part of wxWidgets so far:
-
-
-
-
-
-
- @b wxArchiveFSHandler
-
-
-
-
- A handler for archives such as zip
- and tar. Include file is wx/fs_arc.h. URLs examples:
- "archive.zip#zip:filename", "archive.tar.gz#gzip:#tar:filename".
-
-
-
-
-
- @b wxFilterFSHandler
-
-
-
-
- A handler for compression schemes such
- as gzip. Header is wx/fs_filter.h. URLs are in the form, e.g.:
- "document.ps.gz#gzip:".
-
-
-
-
-
- @b wxInternetFSHandler
-
-
-
-
- A handler for accessing documents
- via HTTP or FTP protocols. Include file is wx/fs_inet.h.
-
-
-
-
-
- @b wxMemoryFSHandler
-
+ There are @b two protocols used in this example: "zip" and "file".
- This handler allows you to access
- data stored in memory (such as bitmaps) as if they were regular files.
- See @ref memoryfshandler_overview for details.
- Include file is wx/fs_mem.h. URL is prefixed with memory:, e.g.
- "memory:myfile.htm"
+ @section overview_fs_wxhtmlfs File Systems Included in wxHTML
+ The following virtual file system handlers are part of wxWidgets so far:
+ @li @b wxArchiveFSHandler:
+ A handler for archives such as zip
+ and tar. Include file is wx/fs_arc.h. URLs examples:
+ "archive.zip#zip:filename", "archive.tar.gz#gzip:#tar:filename".
+ @li @b wxFilterFSHandler:
+ A handler for compression schemes such
+ as gzip. Header is wx/fs_filter.h. URLs are in the form, e.g.:
+ "document.ps.gz#gzip:".
+ @li @b wxInternetFSHandler:
+ A handler for accessing documents
+ via HTTP or FTP protocols. Include file is wx/fs_inet.h.
+ @li @b wxMemoryFSHandler:
+ This handler allows you to access
+ data stored in memory (such as bitmaps) as if they were regular files.
+ See @ref memoryfshandler_overview for details.
+ Include file is wx/fs_mem.h. URL is prefixed with memory:, e.g.
+ "memory:myfile.htm"
+ In addition, wxFileSystem itself can access local files.
- In addition, wxFileSystem itself can access local files.
+ @section overview_fs_init Initializing file system handlers
- @b Initializing file system handlers
- Use wxFileSystem::AddHandler to initialize
- a handler, for example:
+ Use wxFileSystem::AddHandler to initialize a handler, for example:
@code
- #include wx/fs_mem.h
+ #include <wx/fs_mem.h>
...
}
@endcode
- */
-
+*/
/////////////////////////////////////////////////////////////////////////////
-// Name: font
+// Name: font.h
// Purpose: topic overview
// Author: wxWidgets team
// RCS-ID: $Id$
/*!
- @page font_overview wxFont overview
+ @page overview_font wxFont overview
Class: #wxFont, #wxFontDialog
+
A font is an object which determines the appearance of text, primarily
when drawing text to a window or device context. A font is determined by
the following parameters (not all of them have to be specified, of course):
-
-
-
-
-
- Point size
-
-
-
-
- This is the standard way of referring to text size.
-
-
-
-
-
- Family
-
-
-
-
- Supported families are:
- @b wxDEFAULT, wxDECORATIVE, wxROMAN, wxSCRIPT, wxSWISS, wxMODERN.
- @b wxMODERN is a fixed pitch font; the others are either fixed or variable pitch.
-
-
-
-
-
- Style
-
-
-
-
- The value can be @b wxNORMAL, wxSLANT or @b wxITALIC.
-
-
-
-
-
- Weight
-
-
-
-
- The value can be @b wxNORMAL, wxLIGHT or @b wxBOLD.
-
-
-
-
-
- Underlining
-
-
-
-
- The value can be @true or @false.
-
-
-
-
-
- Face name
-
-
-
-
- An optional string specifying the actual typeface to be used. If @NULL,
- a default typeface will chosen based on the family.
-
-
-
-
-
- Encoding
-
-
-
-
- The font encoding (see @b wxFONTENCODING_XXX
- constants and the @ref fontencoding_overview for more
- details)
-
-
-
-
+ @beginDefList
+ @itemdef{Point size, This is the standard way of referring to text size.}
+ @itemdef{Family,
+ Supported families are:
+ @b wxDEFAULT, @b wxDECORATIVE, @b wxROMAN, @b wxSCRIPT, @b wxSWISS, @b wxMODERN.
+ @b wxMODERN is a fixed pitch font; the others are either fixed or variable pitch.}
+ @itemdef{Style, The value can be @b wxNORMAL, @b wxSLANT or @b wxITALIC.}
+ @itemdef{Weight, The value can be @b wxNORMAL, @b wxLIGHT or @b wxBOLD.}
+ @itemdef{Underlining, The value can be @true or @false.}
+ @itemdef{Face name,
+ An optional string specifying the actual typeface to be used. If @NULL,
+ a default typeface will chosen based on the family.}
+ @itemdef{Encoding,
+ The font encoding (see @b wxFONTENCODING_XXX
+ constants and the @ref fontencoding_overview for more
+ details)}
+ @endDefList
Specifying a family, rather than a specific typeface name, ensures a degree of
portability across platforms because a suitable font will be chosen for the
parameters above don't suffice, in general, to identify all the available fonts
and this is where using the native font descriptions may be helpful - see
below.
+
Under Windows, the face name can be one of the installed fonts on the user's
system. Since the choice of fonts differs from system to system, either choose
standard Windows fonts, or if allowing the user to specify a face name, store
the family name with any file that might be transported to a different Windows
machine or other platform.
- @b Note: There is currently a difference between the appearance
- of fonts on the two platforms, if the mapping mode is anything other than
- wxMM_TEXT. Under X, font size is always specified in points. Under MS
- Windows, the unit for text is points but the text is scaled according to the
- current mapping mode. However, user scaling on a device context will also
- scale fonts under both environments.
+ @note There is currently a difference between the appearance
+ of fonts on the two platforms, if the mapping mode is anything other than
+ wxMM_TEXT. Under X, font size is always specified in points. Under MS
+ Windows, the unit for text is points but the text is scaled according to the
+ current mapping mode. However, user scaling on a device context will also
+ scale fonts under both environments.
- @ref nativefontinformation_overview
- @section nativefontinformation Native font information
+ @section overview_font_nativeinfo Native font information
An alternative way of choosing fonts is to use the native font description.
This is the only acceptable solution if the user is allowed to choose the font
be described using only the family name and so, if only family name is stored
permanently, the user would almost surely see a different font in the program
later.
- Instead, you should store the value returned by
- wxFont::GetNativeFontInfoDesc and pass
- it to wxFont::SetNativeFontInfo later to
- recreate exactly the same font.
+
+ Instead, you should store the value returned by wxFont::GetNativeFontInfoDesc and pass
+ it to wxFont::SetNativeFontInfo later to recreate exactly the same font.
+
Note that the contents of this string depends on the platform and shouldn't be
used for any other purpose (in particular, it is not meant to be shown to the
user). Also please note that although the native font information is currently
are available for all the ports and should be used to make your program work
correctly when they are implemented later.
- */
-
+*/
/////////////////////////////////////////////////////////////////////////////
-// Name: fontencoding
+// Name: fontencoding.h
// Purpose: topic overview
// Author: wxWidgets team
// RCS-ID: $Id$
/*!
- @page fontencoding_overview Font encoding overview
+ @page overview_fontencoding Font encoding overview
wxWidgets has support for multiple font encodings.
+
By encoding we mean here the mapping between the character codes and the
letters. Probably the most well-known encoding is (7 bit) ASCII one which is
used almost universally now to represent the letters of the English alphabet
and some other common characters. However, it is not enough to represent the
letters of foreign alphabets and here other encodings come into play. Please
- note that we will only discuss 8-bit fonts here and not
- #Unicode.
+ note that we will only discuss 8-bit fonts here and not #Unicode.
+
Font encoding support is ensured by several classes:
- #wxFont itself, but also
- #wxFontEnumerator and
+ #wxFont itself, but also #wxFontEnumerator and
#wxFontMapper. wxFont encoding support is reflected by
a (new) constructor parameter @e encoding which takes one of the following
values (elements of enumeration type @c wxFontEncoding):
-
-
-
-
-
- wxFONTENCODING_SYSTEM
-
-
-
-
- The default encoding of the underlying
- operating system (notice that this might be a "foreign" encoding for foreign
- versions of Windows 9x/NT).
-
-
-
-
-
- wxFONTENCODING_DEFAULT
-
-
-
-
- The applications default encoding as
- returned by wxFont::GetDefaultEncoding. On
- program startup, the applications default encoding is the same as
- wxFONTENCODING_SYSTEM, but may be changed to make all the fonts created later
- to use it (by default).
-
-
-
-
-
- wxFONTENCODING_ISO8859_1..15
-
-
-
-
- ISO8859 family encodings which are
- usually used by all non-Microsoft operating systems
-
-
-
-
-
- wxFONTENCODING_KOI8
-
-
-
-
- Standard Cyrillic encoding for the Internet
- (but see also wxFONTENCODING_ISO8859_5 and wxFONTENCODING_CP1251)
-
-
-
-
-
- wxFONTENCODING_CP1250
-
-
-
-
- Microsoft analogue of ISO8859-2
-
-
-
-
-
- wxFONTENCODING_CP1251
-
-
-
-
- Microsoft analogue of ISO8859-5
-
-
-
-
-
- wxFONTENCODING_CP1252
-
-
-
-
- Microsoft analogue of ISO8859-1
-
-
-
-
+ @beginDefList
+ @itemdef{wxFONTENCODING_SYSTEM,
+ The default encoding of the underlying
+ operating system (notice that this might be a "foreign" encoding for foreign
+ versions of Windows 9x/NT).}
+ @itemdef{wxFONTENCODING_DEFAULT,
+ The applications default encoding as returned by wxFont::GetDefaultEncoding.
+ On program startup, the applications default encoding is the same as
+ wxFONTENCODING_SYSTEM, but may be changed to make all the fonts created later
+ to use it (by default).}
+ @itemdef{wxFONTENCODING_ISO8859_1..15,
+ ISO8859 family encodings which are
+ usually used by all non-Microsoft operating systems.}
+ @itemdef{wxFONTENCODING_KOI8,
+ Standard Cyrillic encoding for the Internet
+ (but see also wxFONTENCODING_ISO8859_5 and wxFONTENCODING_CP1251).}
+ @itemdef{wxFONTENCODING_CP1250, Microsoft analogue of ISO8859-2}
+ @itemdef{wxFONTENCODING_CP1251, Microsoft analogue of ISO8859-5}
+ @itemdef{wxFONTENCODING_CP1252, Microsoft analogue of ISO8859-1}
+ @endDefList
As you may see, Microsoft's encoding partly mirror the standard ISO8859 ones,
but there are (minor) differences even between ISO8859-1 (Latin1, ISO encoding
for Western Europe) and CP1251 (WinLatin1, standard code page for English
versions of Windows) and there are more of them for other encodings.
+
The situation is particularly complicated with Cyrillic encodings for which
(more than) three incompatible encodings exist: KOI8 (the old standard, widely
used on the Internet), ISO8859-5 (ISO standard for Cyrillic) and CP1251
(WinCyrillic).
+
This abundance of (incompatible) encodings should make it clear that using
encodings is less easy than it might seem. The problems arise both from the
fact that the standard encodings for the given language (say Russian, which is
written in Cyrillic) are different on different platforms and because the
fonts in the given encoding might just not be installed (this is especially a
problem with Unix, or, in general, non-Win32 systems).
+
To clarify, the #wxFontEnumerator
class may be used to enumerate both all available encodings and to find the
facename(s) in which the given encoding exists. If you can find the font in
for KOI8 encoding (only for WinCyrillic one which is quite different), so
#wxFontEnumerator will never return one, even if
the user has installed a KOI8 font on his system.
+
To solve this problem, a #wxFontMapper class is provided.
+
This class stores the mapping between the encodings and the font face
names which support them in #wxConfig object. Of
course, it would be fairly useless if it tried to determine these mappings by
please refer to it and the documentation of the classes mentioned here for
further explanations.
- */
-
+*/
projects / wxWidgets.git / commitdiff
