Class Scale

  • All Implemented Interfaces:
    Drawable

    public class Scale
    extends Control
    Instances of the receiver represent a selectable user interface object that present a range of continuous numeric values.
    Styles:
    HORIZONTAL, VERTICAL
    Events:
    Selection

    Note: Only one of the styles HORIZONTAL and VERTICAL may be specified.

    IMPORTANT: This class is not intended to be subclassed.

    See Also:
    Scale snippets, SWT Example: ControlExample, Sample code and further information
    Restriction:
    This class is not intended to be subclassed by clients.
    • Constructor Detail

      • Scale

        public Scale​(Composite parent,
                     int style)
        Constructs a new instance of this class given its parent and a style value describing its behavior and appearance.

        The style value is either one of the style constants defined in class SWT which is applicable to instances of this class, or must be built by bitwise OR'ing together (that is, using the int "|" operator) two or more of those SWT style constants. The class description lists the style constants that are applicable to the class. Style bits are also inherited from superclasses.

        Parameters:
        parent - a composite control which will be the parent of the new instance (cannot be null)
        style - the style of control to construct
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the parent is null
        SWTException -
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the parent
        • ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
        See Also:
        SWT.HORIZONTAL, SWT.VERTICAL, Widget.checkSubclass(), Widget.getStyle()
    • Method Detail

      • addSelectionListener

        public void addSelectionListener​(SelectionListener listener)
        Adds the listener to the collection of listeners who will be notified when the user changes the receiver's value, by sending it one of the messages defined in the SelectionListener interface.

        widgetSelected is called when the user changes the receiver's value. widgetDefaultSelected is not called.

        Parameters:
        listener - the listener which should be notified
        Throws:
        IllegalArgumentException -
        • ERROR_NULL_ARGUMENT - if the listener is null
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
        See Also:
        SelectionListener, removeSelectionListener(org.eclipse.swt.events.SelectionListener)
      • getIncrement

        public int getIncrement()
        Returns the amount that the receiver's value will be modified by when the up/down (or right/left) arrows are pressed.
        Returns:
        the increment
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • getMaximum

        public int getMaximum()
        Returns the maximum value which the receiver will allow.
        Returns:
        the maximum
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • getMinimum

        public int getMinimum()
        Returns the minimum value which the receiver will allow.
        Returns:
        the minimum
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • getPageIncrement

        public int getPageIncrement()
        Returns the amount that the receiver's value will be modified by when the page increment/decrement areas are selected.
        Returns:
        the page increment
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • getSelection

        public int getSelection()
        Returns the 'selection', which is the receiver's position.
        Returns:
        the selection
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setIncrement

        public void setIncrement​(int increment)
        Sets the amount that the receiver's value will be modified by when the up/down (or right/left) arrows are pressed to the argument, which must be at least one.
        Parameters:
        increment - the new increment (must be greater than zero)
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setMaximum

        public void setMaximum​(int value)
        Sets the maximum value that the receiver will allow. This new value will be ignored if it is not greater than the receiver's current minimum value. If the new maximum is applied then the receiver's selection value will be adjusted if necessary to fall within its new range.
        Parameters:
        value - the new maximum, which must be greater than the current minimum
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setMinimum

        public void setMinimum​(int value)
        Sets the minimum value that the receiver will allow. This new value will be ignored if it is negative or is not less than the receiver's current maximum value. If the new minimum is applied then the receiver's selection value will be adjusted if necessary to fall within its new range.
        Parameters:
        value - the new minimum, which must be nonnegative and less than the current maximum
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setPageIncrement

        public void setPageIncrement​(int pageIncrement)
        Sets the amount that the receiver's value will be modified by when the page increment/decrement areas are selected to the argument, which must be at least one.
        Parameters:
        pageIncrement - the page increment (must be greater than zero)
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      • setSelection

        public void setSelection​(int value)
        Sets the 'selection', which is the receiver's value, to the argument which must be greater than or equal to zero.
        Parameters:
        value - the new selection (must be zero or greater)
        Throws:
        SWTException -
        • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
        • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver