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         By default, all buttons are made of at least the standard button size,
  76         even if their contents is small enough to fit into a smaller size. This
  77         is done for consistency as most platforms use buttons of the same size
  78         in the native dialogs, but can be overridden by specifying this flag.
  79         If it is given, the button will be made just big enough for its
  80         contents. Notice that under MSW the button will still have at least the
  81         standard height, even with this style, if it has a non-empty label.
  82     @style{wxBU_NOTEXT}
  83         Disables the display of the text label in the button even if it has one
  84         or its id is one of the standard stock ids with an associated label:
  85         without using this style a button which is only supposed to show a
  86         bitmap but uses a standard id would display a label too.
  87     @style{wxBORDER_NONE}
  88         Creates a button without border. This is currently implemented in MSW,
  89         GTK2 and OSX/Cocoa and OSX/Carbon ports but in the latter only applies
  90         to buttons with bitmaps and using bitmap of one of the standard sizes
  91         only, namely 128*128, 48*48, 24*24 or 16*16. In all the other cases
  92         wxBORDER_NONE is ignored under OSX/Carbon (these restrictions don't
  93         exist in OSX/Cocoa however).
  94     @endStyleTable
  95
  96     @beginEventEmissionTable{wxCommandEvent}
  97     @event{EVT_BUTTON(id, func)}
  98            Process a @c wxEVT_BUTTON event, when the button is clicked.
  99     @endEventTable
 100
 101     @library{wxcore}
 102     @category{ctrl}
 103     @appearance{button}
 104
 105     @see wxBitmapButton
 106 */
 107 class wxButton : public wxAnyButton
 108 {
 109 public:
 110     /**
 111         Default ctor.
 112     */
 113     wxButton();
 114
 115     /**
 116         Constructor, creating and showing a button.
 117
 118         The preferred way to create standard buttons is to use default value of
 119         @a label. If no label is supplied and @a id is one of standard IDs from
 120         @ref page_stockitems "this list", a standard label will be used. In
 121         other words, if you use a predefined @c wxID_XXX constant, just omit
 122         the label completely rather than specifying it. In particular, help
 123         buttons (the ones with @a id of @c wxID_HELP) under Mac OS X can't
 124         display any label at all and while wxButton will detect if the standard
 125         "Help" label is used and ignore it, using any other label will prevent
 126         the button from correctly appearing as a help button and so should be
 127         avoided.
 128
 129
 130         In addition to that, the button will be decorated with stock icons under GTK+ 2.
 131
 132         @param parent
 133             Parent window. Must not be @NULL.
 134         @param id
 135             Button identifier. A value of @c wxID_ANY indicates a default value.
 136         @param label
 137             Text to be displayed on the button.
 138         @param pos
 139             Button position.
 140         @param size
 141             Button size. If the default size is specified then the button is sized
 142             appropriately for the text.
 143         @param style
 144             Window style. See wxButton class description.
 145         @param validator
 146             Window validator.
 147         @param name
 148             Window name.
 149
 150         @see Create(), wxValidator
 151     */
 152     wxButton(wxWindow* parent, wxWindowID id,
 153              const wxString& label = wxEmptyString,
 154              const wxPoint& pos = wxDefaultPosition,
 155              const wxSize& size = wxDefaultSize,
 156              long style = 0,
 157              const wxValidator& validator = wxDefaultValidator,
 158              const wxString& name = wxButtonNameStr);
 159
 160     /**
 161         Button creation function for two-step creation.
 162         For more details, see wxButton().
 163     */
 164     bool Create(wxWindow* parent, wxWindowID id,
 165                 const wxString& label = wxEmptyString,
 166                 const wxPoint& pos = wxDefaultPosition,
 167                 const wxSize& size = wxDefaultSize,
 168                 long style = 0,
 169                 const wxValidator& validator = wxDefaultValidator,
 170                 const wxString& name = wxButtonNameStr);
 171
 172     /**
 173         Returns @true if an authentication needed symbol is displayed on the
 174         button.
 175
 176         @remarks This method always returns @false if the platform is not
 177                  Windows Vista or newer.
 178
 179         @see SetAuthNeeded()
 180
 181         @since 2.9.1
 182      */
 183     bool GetAuthNeeded() const;
 184
 185
 186     /**
 187         Returns the default size for the buttons. It is advised to make all the dialog
 188         buttons of the same size and this function allows to retrieve the (platform and
 189         current font dependent size) which should be the best suited for this.
 190     */
 191     static wxSize GetDefaultSize();
 192
 193     /**
 194         Returns the string label for the button.
 195
 196         @see SetLabel()
 197     */
 198     wxString GetLabel() const;
 199
 200     /**
 201         Sets whether an authentication needed symbol should be displayed on the
 202         button.
 203
 204         @remarks This method doesn't do anything if the platform is not Windows
 205                  Vista or newer.
 206
 207         @see GetAuthNeeded()
 208
 209         @since 2.9.1
 210      */
 211     void SetAuthNeeded(bool needed = true);
 212
 213
 214     /**
 215         This sets the button to be the default item in its top-level window
 216         (e.g. the panel or the dialog box containing it).
 217
 218         As normal, pressing return causes the default button to be depressed when
 219         the return key is pressed.
 220
 221         See also wxWindow::SetFocus() which sets the keyboard focus for windows
 222         and text panel items, and wxTopLevelWindow::SetDefaultItem().
 223
 224         @remarks Under Windows, only dialog box buttons respond to this function.
 225
 226         @return the old default item (possibly @NULL)
 227     */
 228     virtual wxWindow* SetDefault();
 229
 230     /**
 231         Sets the string label for the button.
 232
 233         @param label
 234             The label to set.
 235     */
 236     void SetLabel(const wxString& label);
 237 };
 238