class button

NAME

button - Base class for clickable buttons

SYNOPSIS

class button : public frame

DESCRIPTION

A button adds input actions to a frame. When a button contains a label, it will center the label's text in its window. An extra indicator (like a LED) may also be included in a button. When clicked with the left mouse button, the button performs some action. At least, it provides visible feedback to the user. When a mouse button is pressed on a button, its 3D effect is reversed. When the mouse button is released, the 3D effect returns to its original state. Further actions depends on the type of button.

Variaties of buttons:

• touch button: performs an action, immediately when it is pressed. A release has no effect. The action of a touch button should not remove the button from the screen. If it does, the release event will be sent to an other window.

  A touch button has a virtual function: click(). This function is called on a ButtonPress event.

• command button: send a command to the application when clicked. It perfroms its action when pressed AND released.
• toggle button: toggles on or off when clicked. It adds a state and an indicator to the touch button. The state of the toggle button reverses when pressed. The indicator shows the current state.

  A toggle button overrides the touch button's function click() and overrides the frame's virtual function redraw(). click() reverses the state of the button. redraw() draws the indicator, which depends on the state.

• radio button: when pressed, turns itself on and its sibling buttons off. The indicator shows the state of the radio button. The parent window of a group of radio buttons can determine the index of the radio button that is 'On'.

SEE ALSO

DIAGNOSTICS