wxWidgets/interface/cshelp.h

/////////////////////////////////////////////////////////////////////////////
// Name:        cshelp.h
// Purpose:     documentation for wxHelpProvider class
// Author:      wxWidgets team
// RCS-ID:      $Id$
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

/**
    @class wxHelpProvider
    @wxheader{cshelp.h}

    wxHelpProvider is an abstract class used by a program implementing
    context-sensitive help to
    show the help text for the given window.

    The current help provider must be explicitly set by the application using
    wxHelpProvider::Set().

    @library{wxcore}
    @category{help}

    @seealso
    wxContextHelp, wxContextHelpButton, wxSimpleHelpProvider,
    wxHelpControllerHelpProvider, wxWindow::SetHelpText, wxWindow::GetHelpTextAtPoint
*/
class wxHelpProvider
{
public:
    /**
        Virtual destructor for any base class.
    */
    ~wxHelpProvider();

    /**
        Associates the text with the given window or id. Although all help
        providers have these functions to allow making wxWindow::SetHelpText
        work, not all of them implement the functions.
    */
    void AddHelp(wxWindowBase* window, const wxString& text);

    /**
        Unlike some other classes, the help provider is not created on demand.
        This must be explicitly done by the application.
    */
    wxHelpProvider* Get();

    //@{
    /**
        This version associates the given text with all windows with this id.
        May be used to set the same help string for all Cancel buttons in
        the application, for example.
    */
    wxString GetHelp(const wxWindowBase* window);
    void AddHelp(wxWindowID id, const wxString& text);
    //@}

    /**
        Removes the association between the window pointer and the help text. This is
        called by the wxWindow destructor. Without this, the table of help strings will
        fill up
        and when window pointers are reused, the wrong help string will be found.
    */
    void RemoveHelp(wxWindowBase* window);

    /**
        Get/set the current, application-wide help provider. Returns
        the previous one.
    */
    wxHelpProvider* Set(wxHelpProvider* helpProvider);

    /**
        Shows help for the given window. Override this function if the help doesn't
        depend on the exact position inside the window, otherwise you need to override
        ShowHelpAtPoint().
        Returns @true if help was shown, or @false if no help was available for this
        window.
    */
    bool ShowHelp(wxWindowBase* window);

    /**
        This function may be overridden to show help for the window when it should
        depend on the position inside the window, By default this method forwards to
        ShowHelp(), so it is enough to only implement
        the latter if the help doesn't depend on the position.
        Returns @true if help was shown, or @false if no help was available for this
        window.
        
        @param window
            Window to show help text for.
        @param point
            Coordinates of the mouse at the moment of help event emission.
        @param origin
            Help event origin, see wxHelpEvent::GetOrigin.
    */
    bool ShowHelpAtPoint(wxWindowBase* window, const wxPoint point,
                         wxHelpEvent::Origin origin);
};


/**
    @class wxHelpControllerHelpProvider
    @wxheader{cshelp.h}

    wxHelpControllerHelpProvider is an implementation of wxHelpProvider which
    supports
    both context identifiers and plain text help strings. If the help text is an
    integer,
    it is passed to wxHelpController::DisplayContextPopup. Otherwise, it shows the
    string
    in a tooltip as per wxSimpleHelpProvider. If you use this with a
    wxCHMHelpController instance
    on windows, it will use the native style of tip window instead of wxTipWindow.

    You can use the convenience function @b wxContextId to convert an integer
    context
    id to a string for passing to wxWindow::SetHelpText.

    @library{wxcore}
    @category{help}

    @seealso
    wxHelpProvider, wxSimpleHelpProvider, wxContextHelp, wxWindow::SetHelpText,
    wxWindow::GetHelpTextAtPoint
*/
class wxHelpControllerHelpProvider : public wxSimpleHelpProvider
{
public:
    /**
        Note that the instance doesn't own the help controller. The help controller
        should be deleted separately.
    */
    wxHelpControllerHelpProvider(wxHelpControllerBase* hc = NULL);

    /**
        Returns the help controller associated with this help provider.
    */
    wxHelpControllerBase* GetHelpController() const;

    /**
        Sets the help controller associated with this help provider.
    */
    void SetHelpController(wxHelpControllerBase* hc);
};


/**
    @class wxContextHelp
    @wxheader{cshelp.h}

    This class changes the cursor to a query and puts the application into a
    'context-sensitive help mode'.
    When the user left-clicks on a window within the specified window, a wxEVT_HELP
    event is
    sent to that control, and the application may respond to it by popping up some
    help.

    For example:

    @code
    wxContextHelp contextHelp(myWindow);
    @endcode

    There are a couple of ways to invoke this behaviour implicitly:

     Use the wxDIALOG_EX_CONTEXTHELP style for a dialog (Windows only). This will
    put a question mark
    in the titlebar, and Windows will put the application into context-sensitive
    help mode automatically,
    with further programming.
     Create a wxContextHelpButton, whose predefined behaviour is to create a
    context help object.
    Normally you will write your application so that this button is only added to a
    dialog for non-Windows platforms
    (use wxDIALOG_EX_CONTEXTHELP on Windows).

    Note that on Mac OS X, the cursor does not change when in context-sensitive
    help mode.

    @library{wxcore}
    @category{help}

    @seealso
    wxHelpEvent, wxHelpController, wxContextHelpButton
*/
class wxContextHelp : public wxObject
{
public:
    /**
        Constructs a context help object, calling BeginContextHelp() if
        @a doNow is @true (the default).
        If @a window is @NULL, the top window is used.
    */
    wxContextHelp(wxWindow* window = NULL, bool doNow = true);

    /**
        Destroys the context help object.
    */
    ~wxContextHelp();

    /**
        Puts the application into context-sensitive help mode. @a window is the window
        which will be used to catch events; if @NULL, the top window will be used.
        Returns @true if the application was successfully put into context-sensitive
        help mode.
        This function only returns when the event loop has finished.
    */
    bool BeginContextHelp(wxWindow* window = NULL);

    /**
        Ends context-sensitive help mode. Not normally called by the application.
    */
    bool EndContextHelp();
};


/**
    @class wxContextHelpButton
    @wxheader{cshelp.h}

    Instances of this class may be used to add a question mark button that when
    pressed, puts the
    application into context-help mode. It does this by creating a wxContextHelp
    object which itself
    generates a wxEVT_HELP event when the user clicks on a window.

    On Windows, you may add a question-mark icon to a dialog by use of the
    wxDIALOG_EX_CONTEXTHELP extra style, but
    on other platforms you will have to add a button explicitly, usually next to
    OK, Cancel or similar buttons.

    @library{wxcore}
    @category{help}

    @seealso
    wxBitmapButton, wxContextHelp
*/
class wxContextHelpButton : public wxBitmapButton
{
public:
    //@{
    /**
        Constructor, creating and showing a context help button.
        
        @param parent
            Parent window. Must not be @NULL.
        @param id
            Button identifier. Defaults to wxID_CONTEXT_HELP.
        @param pos
            Button position.
        @param size
            Button size. If wxDefaultSize is specified then the button is
        sized
            appropriately for the question mark bitmap.
        @param style
            Window style.
    */
    wxContextHelpButton();
    wxContextHelpButton(wxWindow* parent,
                        wxWindowID id = wxID_CONTEXT_HELP,
                        const wxPoint& pos = wxDefaultPosition,
                        const wxSize& size = wxDefaultSize,
                        long style = wxBU_AUTODRAW);
    //@}
};


/**
    @class wxSimpleHelpProvider
    @wxheader{cshelp.h}

    wxSimpleHelpProvider is an implementation of wxHelpProvider which supports
    only plain text help strings, and shows the string associated with the
    control (if any) in a tooltip.

    @library{wxcore}
    @category{help}

    @seealso
    wxHelpProvider, wxHelpControllerHelpProvider, wxContextHelp,
    wxWindow::SetHelpText, wxWindow::GetHelpTextAtPoint
*/
class wxSimpleHelpProvider : public wxHelpProvider
{
public:

};