Class Spinner

All Implemented Interfaces:
Drawable

public class Spinner extends Composite
Instances of this class are selectable user interface objects that allow the user to enter and modify numeric values.

Note that although this class is a subclass of Composite, it does not make sense to add children to it, or set a layout on it.

Styles:
READ_ONLY, WRAP
Events:
Selection, Modify, Verify

IMPORTANT: This class is not intended to be subclassed.

Since:
3.1
See Also:
Restriction:
This class is not intended to be subclassed by clients.
  • Field Details

    • LIMIT

      public static final int LIMIT
      the operating system limit for the number of characters that the text field in an instance of this class can hold
      Since:
      3.4
  • Constructor Details

    • Spinner

      public Spinner(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:
  • Method Details

    • checkSubclass

      protected void checkSubclass()
      Description copied from class: Widget
      Checks that this class can be subclassed.

      The SWT class library is intended to be subclassed only at specific, controlled points (most notably, Composite and Canvas when implementing new widgets). This method enforces this rule unless it is overridden.

      IMPORTANT: By providing an implementation of this method that allows a subclass of a class which does not normally allow subclassing to be created, the implementer agrees to be fully responsible for the fact that any such subclass will likely fail between SWT releases and will be strongly platform specific. No support is provided for user-written classes which are implemented in this fashion.

      The ability to subclass outside of the allowed SWT classes is intended purely to enable those not on the SWT development team to implement patches in order to get around specific limitations in advance of when those limitations can be addressed by the team. Subclassing should not be attempted without an intimate and detailed understanding of the hierarchy.

      Overrides:
      checkSubclass in class Composite
    • addModifyListener

      public void addModifyListener(ModifyListener listener)
      Adds the listener to the collection of listeners who will be notified when the receiver's text is modified, by sending it one of the messages defined in the ModifyListener interface.
      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:
    • addSelectionListener

      public void addSelectionListener(SelectionListener listener)
      Adds the listener to the collection of listeners who will be notified when the control is selected by the user, by sending it one of the messages defined in the SelectionListener interface.

      widgetSelected is not called for texts. widgetDefaultSelected is typically called when ENTER is pressed in a single-line text.

      Parameters:
      listener - the listener which should be notified when the control is selected by the user
      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:
    • copy

      public void copy()
      Copies the selected text.

      The current selection is copied to the clipboard.

      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
    • cut

      public void cut()
      Cuts the selected text.

      The current selection is first copied to the clipboard and then deleted from the widget.

      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
    • getDigits

      public int getDigits()
      Returns the number of decimal places used by the receiver.
      Returns:
      the digits
      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
    • getIncrement

      public int getIncrement()
      Returns the amount that the receiver's value will be modified by when the up/down 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 position will be modified by when the page up/down keys are pressed.
      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
    • getText

      public String getText()
      Returns a string containing a copy of the contents of the receiver's text field, or an empty string if there are no contents.
      Returns:
      the receiver's text
      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
      Since:
      3.4
    • getTextLimit

      public int getTextLimit()
      Returns the maximum number of characters that the receiver's text field is capable of holding. If this has not been changed by setTextLimit(), it will be the constant Spinner.LIMIT.
      Returns:
      the text limit
      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
      Since:
      3.4
      See Also:
    • paste

      public void paste()
      Pastes text from clipboard.

      The selected text is deleted from the widget and new text inserted from the clipboard.

      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
    • removeModifyListener

      public void removeModifyListener(ModifyListener listener)
      Removes the listener from the collection of listeners who will be notified when the receiver's text is modified.
      Parameters:
      listener - the listener which should no longer 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:
    • removeSelectionListener

      public void removeSelectionListener(SelectionListener listener)
      Removes the listener from the collection of listeners who will be notified when the control is selected by the user.
      Parameters:
      listener - the listener which should no longer 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:
    • setDigits

      public void setDigits(int value)
      Sets the number of decimal places used by the receiver.

      The digit setting is used to allow for floating point values in the receiver. For example, to set the selection to a floating point value of 1.37 call setDigits() with a value of 2 and setSelection() with a value of 137. Similarly, if getDigits() has a value of 2 and getSelection() returns 137 this should be interpreted as 1.37. This applies to all numeric APIs.

      Parameters:
      value - the new digits (must be greater than or equal to zero)
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the value is less than zero
      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 value)
      Sets the amount that the receiver's value will be modified by when the up/down arrows are pressed to the argument, which must be at least one.
      Parameters:
      value - 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 less 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 or equal to 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 greater 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 less than or equal to 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 value)
      Sets the amount that the receiver's position will be modified by when the page up/down keys are pressed to the argument, which must be at least one.
      Parameters:
      value - 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 position, to the argument. If the argument is not within the range specified by minimum and maximum, it will be adjusted to fall within this range.
      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
    • setTextLimit

      public void setTextLimit(int limit)
      Sets the maximum number of characters that the receiver's text field is capable of holding to be the argument.

      To reset this value to the default, use setTextLimit(Spinner.LIMIT). Specifying a limit value larger than Spinner.LIMIT sets the receiver's limit to Spinner.LIMIT.

      Parameters:
      limit - new text limit
      Throws:
      IllegalArgumentException -
      • ERROR_CANNOT_BE_ZERO - if the limit is zero
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
      Since:
      3.4
      See Also:
    • setValues

      public void setValues(int selection, int minimum, int maximum, int digits, int increment, int pageIncrement)
      Sets the receiver's selection, minimum value, maximum value, digits, increment and page increment all at once.

      Note: This is similar to setting the values individually using the appropriate methods, but may be implemented in a more efficient fashion on some platforms.

      Parameters:
      selection - the new selection value
      minimum - the new minimum value
      maximum - the new maximum value
      digits - the new digits value
      increment - the new increment value
      pageIncrement - the new pageIncrement value
      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
      Since:
      3.2