Call wxEvtHandler::TryBefore() only once from ProcessEvent().

[wxWidgets.git] / interface / wx / cursor.h

/////////////////////////////////////////////////////////////////////////////
// Name:        cursor.h
// Purpose:     interface of wxCursor
// Author:      wxWidgets team
// RCS-ID:      $Id$
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

/**
    @class wxCursor

    A cursor is a small bitmap usually used for denoting where the mouse
    pointer is, with a picture that might indicate the interpretation of a
    mouse click. As with icons, cursors in X and MS Windows are created in a
    different manner. Therefore, separate cursors will be created for the
    different environments. Platform-specific methods for creating a wxCursor
    object are catered for, and this is an occasion where conditional
    compilation will probably be required (see wxIcon for an example).

    A single cursor object may be used in many windows (any subwindow type).
    The wxWidgets convention is to set the cursor for a window, as in X, rather
    than to set it globally as in MS Windows, although a global wxSetCursor()
    function is also available for MS Windows use.

    @section cursor_custom Creating a Custom Cursor

    The following is an example of creating a cursor from 32x32 bitmap data
    (down_bits) and a mask (down_mask) where 1 is black and 0 is white for the
    bits, and 1 is opaque and 0 is transparent for the mask.
    It works on Windows and GTK+.

    @code
    static char down_bits[] = { 255, 255, 255, 255, 31,
        255, 255, 255, 31, 255, 255, 255, 31, 255, 255, 255,
        31, 255, 255, 255, 31, 255, 255, 255, 31, 255, 255,
        255, 31, 255, 255, 255, 31, 255, 255, 255, 25, 243,
        255, 255, 19, 249, 255, 255, 7, 252, 255, 255, 15, 254,
        255, 255, 31, 255, 255, 255, 191, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
        255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
        255 };

    static char down_mask[] = { 240, 1, 0, 0, 240, 1,
        0, 0, 240, 1, 0, 0, 240, 1, 0, 0, 240, 1, 0, 0, 240, 1,
        0, 0, 240, 1, 0, 0, 240, 1, 0, 0, 255, 31, 0, 0, 255,
        31, 0, 0, 254, 15, 0, 0, 252, 7, 0, 0, 248, 3, 0, 0,
        240, 1, 0, 0, 224, 0, 0, 0, 64, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0 };

    #ifdef __WXMSW__
        wxBitmap down_bitmap(down_bits, 32, 32);
        wxBitmap down_mask_bitmap(down_mask, 32, 32);

        down_bitmap.SetMask(new wxMask(down_mask_bitmap));
        wxImage down_image = down_bitmap.ConvertToImage();
        down_image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X, 6);
        down_image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y, 14);
        wxCursor down_cursor = wxCursor(down_image);
    #elif defined(__WXGTK__) or defined(__WXMOTIF__)
        wxCursor down_cursor = wxCursor(down_bits, 32, 32, 6, 14,
                                        down_mask, wxWHITE, wxBLACK);
    #endif
    @endcode

    @library{wxcore}
    @category{gdi}

    @stdobjects
    - ::wxNullCursor
    - ::wxSTANDARD_CURSOR
    - ::wxHOURGLASS_CURSOR
    - ::wxCROSS_CURSOR

    @see wxBitmap, wxIcon, wxWindow::SetCursor(), wxSetCursor(), ::wxStockCursor
*/
class wxCursor : public wxGDIObject
{
public:
    /**
        Default constructor.
    */
    wxCursor();

    /**
        Constructs a cursor by passing an array of bits (XBM data).

        The parameters @a fg and @a bg have an effect only on GTK+, and force
        the cursor to use particular background and foreground colours.

        If either @a hotSpotX or @a hotSpotY is -1, the hotspot will be the
        centre of the cursor image (Motif only).

        @param bits
            An array of XBM data bits.
        @param width
            Cursor width.
        @param height
            Cursor height.
        @param hotSpotX
            Hotspot x coordinate (relative to the top left of the image).
        @param hotSpotY
            Hotspot y coordinate (relative to the top left of the image).
        @param maskBits
            Bits for a mask bitmap.

        @onlyfor{wxgtk,wxmotif}

        @beginWxPerlOnly
        In wxPerl use Wx::Cursor->newData(bits, width, height, hotSpotX = -1, hotSpotY = -1, maskBits = 0).
        @endWxPerlOnly
    */
    wxCursor(const char bits[], int width, int height,
             int hotSpotX = -1, int hotSpotY = -1,
             const char maskBits[] = NULL);

    /**
        Constructs a cursor by passing a string resource name or filename.

        The arguments @a hotSpotX and @a hotSpotY are only used when there's no
        hotspot info in the resource/image-file to load (e.g. when using
        @c wxBITMAP_TYPE_ICO under wxMSW or @c wxBITMAP_TYPE_XPM under wxGTK).

        @param cursorName
            The name of the resource or the image file to load.
        @param type
            Icon type to load. It defaults to @c wxCURSOR_DEFAULT_TYPE,
            which is a @#define associated to different values on different
            platforms:
            - under Windows, it defaults to @c wxBITMAP_TYPE_CUR_RESOURCE.
              Other permitted types under Windows are @c wxBITMAP_TYPE_CUR
              (to load a cursor from a .cur cursor file) and @c wxBITMAP_TYPE_ICO
              (to load a cursor from a .ico icon file).
            - under MacOS, it defaults to @c wxBITMAP_TYPE_MACCURSOR_RESOURCE;
              when specifying a string resource name, first the color cursors 'crsr' 
              and then the black/white cursors 'CURS' in the resource chain are scanned 
              through.
            - under GTK, it defaults to @c wxBITMAP_TYPE_XPM. 
              See the wxCursor(const wxImage& image) ctor for more info.
            - under X11, it defaults to @c wxBITMAP_TYPE_XPM.
            - under Motif, it defaults to @c wxBITMAP_TYPE_XBM.
        @param hotSpotX
            Hotspot x coordinate (relative to the top left of the image).
        @param hotSpotY
            Hotspot y coordinate (relative to the top left of the image).
    */
    wxCursor(const wxString& cursorName,
             wxBitmapType type = wxCURSOR_DEFAULT_TYPE,
             int hotSpotX = 0, int hotSpotY = 0);

    /**
        Constructs a cursor using a cursor identifier.

        @param cursorId
            A stock cursor identifier. See ::wxStockCursor.
    */
    wxCursor(wxStockCursor cursorId);

    /**
        Constructs a cursor from a wxImage. If cursor are monochrome on the
        current platform, colors with the RGB elements all greater than 127
        will be foreground, colors less than this background. The mask (if any)
        will be used to specify the transparent area.

        In wxMSW the foreground will be white and the background black.
        If the cursor is larger than 32x32 it is resized.

        In wxGTK, colour cursors and alpha channel are supported (starting from
        GTK+ 2.2). Otherwise the two most frequent colors will be used for
        foreground and background. In any case, the cursor will be displayed
        at the size of the image.

        In wxMac, if the cursor is larger than 16x16 it is resized and
        currently only shown as black/white (mask respected).
    */
    wxCursor(const wxImage& image);

    /**
        Copy constructor, uses @ref overview_refcount "reference counting".

        @param cursor
            Pointer or reference to a cursor to copy.
    */
    wxCursor(const wxCursor& cursor);

    /**
        Destroys the cursor. See
        @ref overview_refcount_destruct "reference-counted object destruction"
        for more info.

        A cursor can be reused for more than one window, and does not get
        destroyed when the window is destroyed. wxWidgets destroys all cursors
        on application exit, although it is best to clean them up explicitly.
    */
    virtual ~wxCursor();

    /**
        Returns @true if cursor data is present.
    */
    virtual bool IsOk() const;

    /**
        Assignment operator, using @ref overview_refcount "reference counting".
    */
    wxCursor& operator =(const wxCursor& cursor);
};


/**
    @name Predefined cursors.

    @see wxStockCursor
*/
//@{
wxCursor wxNullCursor;
wxCursor* wxSTANDARD_CURSOR;
wxCursor* wxHOURGLASS_CURSOR;
wxCursor* wxCROSS_CURSOR;
//@}