interface/wx/button.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        button.h
   3 // Purpose:     interface of wxButton
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows licence
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9
  10 /**
  11     @class wxButton
  12
  13     A button is a control that contains a text string, and is one of the most
  14     common elements of a GUI.
  15
  16     It may be placed on a @ref wxDialog "dialog box" or on a @ref wxPanel panel,
  17     or indeed on almost any other window.
  18
  19     By default, i.e. if none of the alignment styles are specified, the label
  20     is centered both horizontally and vertically. If the button has both a
  21     label and a bitmap, the alignment styles above specify the location of the
  22     rectangle combining both the label and the bitmap and the bitmap position
  23     set with wxButton::SetBitmapPosition() defines the relative position of the
  24     bitmap with respect to the label (however currently non-default alignment
  25     combinations are not implemented on all platforms).
  26
  27     Since version 2.9.1 wxButton supports showing both text and an image
  28     (currently only when using wxMSW, wxGTK or wxOSX/Cocoa ports), see
  29     SetBitmap() and SetBitmapLabel(), SetBitmapDisabled() &c methods. In the
  30     previous wxWidgets versions this functionality was only available in (the
  31     now trivial) wxBitmapButton class which was only capable of showing an
  32     image without text.
  33
  34     A button may have either a single image for all states or different images
  35     for the following states (different images are not currently supported
  36     under OS X where the normal image is used for all states):
  37     @li @b normal: the default state
  38     @li @b disabled: bitmap shown when the button is disabled.
  39     @li @b pressed: bitmap shown when the button is pushed (e.g. while the user
  40         keeps the mouse button pressed on it)
  41     @li @b focus: bitmap shown when the button has keyboard focus (but is not
  42         pressed as in this case the button is in the pressed state)
  43     @li @b current: bitmap shown when the mouse is over the button (but it is
  44         not pressed although it may have focus). Notice that if current bitmap
  45         is not specified but the current platform UI uses hover images for the
  46         buttons (such as Windows XP or GTK+), then the focus bitmap is used for
  47         hover state as well. This makes it possible to set focus bitmap only to
  48         get reasonably good behaviour on all platforms.
  49
  50     All of the bitmaps must be of the same size and the normal bitmap must be
  51     set first (to a valid bitmap), before setting any other ones. Also, if the
  52     size of the bitmaps is changed later, you need to change the size of the
  53     normal bitmap before setting any other bitmaps with the new size (and you
  54     do need to reset all of them as their original values can be lost when the
  55     normal bitmap size changes).
  56
  57     The position of the image inside the button be configured using
  58     SetBitmapPosition(). By default the image is on the left of the text.
  59
  60     Please also notice that GTK+ uses a global setting called @c gtk-button-images
  61     to determine if the images should be shown in the buttons
  62     at all. If it is off (which is the case in e.g. Gnome 2.28 by default), no
  63     images will be shown, consistently with the native behaviour.
  64
  65     @beginStyleTable
  66     @style{wxBU_LEFT}
  67         Left-justifies the label. Windows and GTK+ only.
  68     @style{wxBU_TOP}
  69         Aligns the label to the top of the button. Windows and GTK+ only.
  70     @style{wxBU_RIGHT}
  71         Right-justifies the bitmap label. Windows and GTK+ only.
  72     @style{wxBU_BOTTOM}
  73         Aligns the label to the bottom of the button. Windows and GTK+ only.
  74     @style{wxBU_EXACTFIT}
  75         Creates the button as small as possible instead of making it of the
  76         standard size (which is the default behaviour ).
  77     @style{wxBU_NOTEXT}
  78         Disables the display of the text label in the button even if it has one
  79         or its id is one of the standard stock ids with an associated label:
  80         without using this style a button which is only supposed to show a
  81         bitmap but uses a standard id would display a label too.
  82     @style{wxBORDER_NONE}
  83         Creates a button without border. This is currently implemented in MSW,
  84         GTK2 and OSX/Carbon ports but in the latter only applies to buttons
  85         with bitmaps and using bitmap of one of the standard sizes only, namely
  86         128*128, 48*48, 24*24 or 16*16. In all the other cases wxBORDER_NONE is
  87         ignored under OSX.
  88     @endStyleTable
  89
  90     @beginEventEmissionTable{wxCommandEvent}
  91     @event{EVT_BUTTON(id, func)}
  92            Process a @c wxEVT_COMMAND_BUTTON_CLICKED event, when the button is clicked.
  93     @endEventTable
  94
  95     @library{wxcore}
  96     @category{ctrl}
  97     @appearance{button.png}
  98
  99     @see wxBitmapButton
 100 */
 101 class wxButton : public wxAnyButton
 102 {
 103 public:
 104     /**
 105         Default ctor.
 106     */
 107     wxButton();
 108
 109     /**
 110         Constructor, creating and showing a button.
 111
 112         The preferred way to create standard buttons is to use default value of
 113         @a label. If no label is supplied and @a id is one of standard IDs from
 114         @ref page_stockitems "this list", a standard label will be used. In
 115         other words, if you use a predefined @c wxID_XXX constant, just omit
 116         the label completely rather than specifying it. In particular, help
 117         buttons (the ones with @a id of @c wxID_HELP) under Mac OS X can't
 118         display any label at all and while wxButton will detect if the standard
 119         "Help" label is used and ignore it, using any other label will prevent
 120         the button from correctly appearing as a help button and so should be
 121         avoided.
 122
 123
 124         In addition to that, the button will be decorated with stock icons under GTK+ 2.
 125
 126         @param parent
 127             Parent window. Must not be @NULL.
 128         @param id
 129             Button identifier. A value of @c wxID_ANY indicates a default value.
 130         @param label
 131             Text to be displayed on the button.
 132         @param pos
 133             Button position.
 134         @param size
 135             Button size. If the default size is specified then the button is sized
 136             appropriately for the text.
 137         @param style
 138             Window style. See wxButton class description.
 139         @param validator
 140             Window validator.
 141         @param name
 142             Window name.
 143
 144         @see Create(), wxValidator
 145     */
 146     wxButton(wxWindow* parent, wxWindowID id,
 147              const wxString& label = wxEmptyString,
 148              const wxPoint& pos = wxDefaultPosition,
 149              const wxSize& size = wxDefaultSize,
 150              long style = 0,
 151              const wxValidator& validator = wxDefaultValidator,
 152              const wxString& name = wxButtonNameStr);
 153
 154     /**
 155         Button creation function for two-step creation.
 156         For more details, see wxButton().
 157     */
 158     bool Create(wxWindow* parent, wxWindowID id,
 159                 const wxString& label = wxEmptyString,
 160                 const wxPoint& pos = wxDefaultPosition,
 161                 const wxSize& size = wxDefaultSize,
 162                 long style = 0,
 163                 const wxValidator& validator = wxDefaultValidator,
 164                 const wxString& name = wxButtonNameStr);
 165
 166     /**
 167         Returns @true if an authentication needed symbol is displayed on the
 168         button.
 169
 170         @remarks This method always returns @false if the platform is not
 171                  Windows Vista or newer.
 172
 173         @see SetAuthNeeded()
 174
 175         @since 2.9.1
 176      */
 177     bool GetAuthNeeded() const;
 178
 179
 180     /**
 181         Returns the default size for the buttons. It is advised to make all the dialog
 182         buttons of the same size and this function allows to retrieve the (platform and
 183         current font dependent size) which should be the best suited for this.
 184     */
 185     static wxSize GetDefaultSize();
 186
 187     /**
 188         Returns the string label for the button.
 189
 190         @see SetLabel()
 191     */
 192     wxString GetLabel() const;
 193
 194     /**
 195         Sets whether an authentication needed symbol should be displayed on the
 196         button.
 197
 198         @remarks This method doesn't do anything if the platform is not Windows
 199                  Vista or newer.
 200
 201         @see GetAuthNeeded()
 202
 203         @since 2.9.1
 204      */
 205     void SetAuthNeeded(bool needed = true);
 206
 207
 208     /**
 209         This sets the button to be the default item in its top-level window
 210         (e.g. the panel or the dialog box containing it).
 211
 212         As normal, pressing return causes the default button to be depressed when
 213         the return key is pressed.
 214
 215         See also wxWindow::SetFocus() which sets the keyboard focus for windows
 216         and text panel items, and wxTopLevelWindow::SetDefaultItem().
 217
 218         @remarks Under Windows, only dialog box buttons respond to this function.
 219
 220         @return the old default item (possibly @NULL)
 221     */
 222     virtual wxWindow* SetDefault();
 223
 224     /**
 225         Sets the string label for the button.
 226
 227         @param label
 228             The label to set.
 229     */
 230     void SetLabel(const wxString& label);
 231 };
 232