fltk::Button Class Reference

Inherits fltk::Widget.

Inherited by BButton, fltk::CheckButton, fltk::HighlightButton, fltk::RepeatButton, fltk::ReturnButton, and fltk::ToggleButton.

List of all members.

Public Types

enum  { HIDDEN = 3 }

Public Member Functions

 Button (int, int, int, int, const char *=0)
void draw (int glyph_width) const
virtual void draw ()
int handle (int event, const Rectangle &)
int handle (int)
bool value () const
bool value (bool v)

Static Public Attributes

static NamedStyledefault_style = &::style

Detailed Description

Buttons generate callbacks when they are clicked by the user. You control exactly when and how by changing the values for when():

  • fltk::WHEN_NEVER: The callback is not done, instead changed() is turned on.
  • fltk::WHEN_RELEASE: This is the default, the callback is done after the user successfully clicks the button (i.e. they let it go with the mouse still pointing at it), or when a shortcut is typed.
  • fltk::WHEN_CHANGED : The callback is done each time the value() changes (when the user pushes and releases the button, and as the mouse is dragged around in and out of the button).

Buttons can also generate callbacks in response to fltk::SHORTCUT events. The button can either have an explicit shortcut() value or a letter shortcut can be indicated in the label() with an '&' character before it. For the label shortcut it does not matter if Alt is held down, but if you have an input field in the same window, the user will have to hold down the Alt key so that the input field does not eat the event first as an fltk::KEY event.


Member Enumeration Documentation

anonymous enum

Back-compatibility enumeration


Indicates that the button should be hidden.

Constructor & Destructor Documentation

Button::Button ( int  x,
int  y,
int  w,
int  h,
const char *  l = 0 

The default constructor calls Widget() with x, y, w, h and l. It also sets the style to the default_style

xThe x position of the Button, relative to the group
yThe y position of the Button, relative to the group
wThe width of the Button
hThe height of the Button
lThe Button's label

Member Function Documentation

void Button::draw ( void  ) [virtual]

The virtual draw() function makes sure the button isn't hidden, then calls Button::draw(int glyph_width) with a width of 0

Reimplemented from fltk::Widget.

Reimplemented in fltk::CheckButton, and fltk::ReturnButton.

void Button::draw ( int  glyph_width) const

This function provides a mess of back-compatabilty and Windows emulation to subclasses of Button to draw with. It will draw the button according to the current state of being pushed and it's state().

glyph_widthIf non-zero is passed for glyph_width then the glyph() is drawn in that space on the left (or on the right if negative), and it assummes the glyph indicates the state(), so the box is only used to indicate the pushed state.
int Button::handle ( int  event,
const Rectangle rectangle 

The Button's own handle function. See Widget::handle

eventThe event to handle
rectangleThe rectangle this event occurred within. You can change this value, or inspect it in a subclass, to determine what you want your button to do if the user clicks on different sections
int Button::handle ( int  event) [virtual]

Wrapper around Button::handle(int event, const Rectangle& rectangle)

eventThe event that this button has received
1 if the button has successfully handled the event,
0 otherwise

Reimplemented from fltk::Widget.

Reimplemented in fltk::RepeatButton.

bool Button::value ( ) const [inline]

The current value. The ToggleButton subclass provides the ability for the user to change this value permanently, otherwise it is just temporary while the user is holding the button down.

This is the same as Widget::state().

true if the button is pushed down, false otherwise
bool Button::value ( bool  v) [inline]

Changes the value() and redraws the button. This is the same function as Widget::state(). See also Widget::set(), Widget::clear(), and Widget::setonly().

vThe new value for the button; true for pushed down, false for not pushed down. If you pass "true" as the value, a normal button will draw pushed-in, until the user clicks it and releases it.
true if the new value is different, false otherwise

Member Data Documentation

NamedStyle * Button::default_style = &::style [static]

This sets the Button's default style to one with no revert function It thus inherits its style from the "default" style and from Group::default_style

Reimplemented from fltk::Widget.

Reimplemented in fltk::CheckButton, fltk::HighlightButton, fltk::LightButton, fltk::RadioButton, and fltk::ReturnButton.

The documentation for this class was generated from the following files: