Class Spinner

All Implemented Interfaces:
Adaptable, 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.

Styles:
READ_ONLY, WRAP
Events:
Selection, Modify

IMPORTANT: This class is not intended to be subclassed.

Since:
1.0
  • Field Details

    • LIMIT

      public static final int LIMIT
      the limit for the number of characters that the text field in an instance of this class can hold
      Since:
      1.3
      See Also:
  • 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

    • 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
    • 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
      Since:
      1.3
    • 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
    • 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
    • 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
    • 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 equals 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
    • 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
    • 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
    • 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
    • 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
    • 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
    • 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
    • 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
    • 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:
      1.3
    • setTextLimit

      public void setTextLimit(int textLimit)
      Sets the maximum number of characters that the receiver is capable of holding to be the argument.

      Instead of trying to set the text limit to zero, consider creating a read-only text widget.

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

      Parameters:
      textLimit - 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:
      1.3
      See Also:
    • getTextLimit

      public int getTextLimit()
      Returns the maximum number of characters that the receiver is capable of holding.

      If this has not been changed by setTextLimit(), it will be the constant Text.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:
      1.3
      See Also:
    • computeSize

      public Point computeSize(int wHint, int hHint, boolean changed)
      Description copied from class: Control
      Returns the preferred size of the receiver.

      The preferred size of a control is the size that it would best be displayed at. The width hint and height hint arguments allow the caller to ask a control questions such as "Given a particular width, how high does the control need to be to show all of the contents?" To indicate that the caller does not wish to constrain a particular dimension, the constant SWT.DEFAULT is passed for the hint.

      If the changed flag is true, it indicates that the receiver's contents have changed, therefore any caches that a layout manager containing the control may have been keeping need to be flushed. When the control is resized, the changed flag will be false, so layout manager caches can be retained.

      Overrides:
      computeSize in class Composite
      Parameters:
      wHint - the width hint (can be SWT.DEFAULT)
      hHint - the height hint (can be SWT.DEFAULT)
      changed - true if the control's contents have changed, and false otherwise
      Returns:
      the preferred size of the control.
      See Also:
    • computeTrim

      public Rectangle computeTrim(int x, int y, int width, int height)
      Description copied from class: Scrollable
      Given a desired client area for the receiver (as described by the arguments), returns the bounding rectangle which would be required to produce that client area.

      In other words, it returns a rectangle such that, if the receiver's bounds were set to that rectangle, the area of the receiver which is capable of displaying data (that is, not covered by the "trimmings") would be the rectangle described by the arguments (relative to the receiver's parent).

      Overrides:
      computeTrim in class Scrollable
      Parameters:
      x - the desired x coordinate of the client area
      y - the desired y coordinate of the client area
      width - the desired width of the client area
      height - the desired height of the client area
      Returns:
      the required bounds to produce the given client area
      See Also:
    • 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:
    • 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:
    • 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
      Since:
      1.2
      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
      Since:
      1.2
      See Also:
    • getAdapter

      public <T> T getAdapter(Class<T> adapter)
      Description copied from class: Widget
      Implementation of the Adaptable interface.

      IMPORTANT: This method is not part of the RWT public API. It is marked public only so that it can be shared within the packages provided by RWT. It should never be accessed from application code.

      Specified by:
      getAdapter in interface Adaptable
      Overrides:
      getAdapter in class Composite
      Parameters:
      adapter - the lookup class
      Returns:
      an object that can be cast to the given class or null if there is no adapter associated with the given class.