Package org.eclipse.swt.widgets

Class Decorations

java.lang.Object
org.eclipse.swt.widgets.Widget
org.eclipse.swt.widgets.Control
org.eclipse.swt.widgets.Scrollable
org.eclipse.swt.widgets.Composite
org.eclipse.swt.widgets.Canvas
org.eclipse.swt.widgets.Decorations
All Implemented Interfaces:
Drawable
Direct Known Subclasses:
Shell
public class Decorations extends Canvas
Instances of this class provide the appearance and behavior of Shells, but are not top level shells or dialogs. Class Shell shares a significant amount of code with this class, and is a subclass.

IMPORTANT: This class was intended to be abstract and should never be referenced or instantiated. Instead, the class Shell should be used.

Instances are always displayed in one of the maximized, minimized or normal states:

  • When an instance is marked as maximized, the window manager will typically resize it to fill the entire visible area of the display, and the instance is usually put in a state where it can not be resized (even if it has style RESIZE) until it is no longer maximized.
  • When an instance is in the normal state (neither maximized or minimized), its appearance is controlled by the style constants which were specified when it was created and the restrictions of the window manager (see below).
  • When an instance has been marked as minimized, its contents (client area) will usually not be visible, and depending on the window manager, it may be "iconified" (that is, replaced on the desktop by a small simplified representation of itself), relocated to a distinguished area of the screen, or hidden. Combinations of these changes are also possible.
Note: The styles supported by this class must be treated as HINTs, since the window manager for the desktop on which the instance is visible has ultimate control over the appearance and behavior of decorations. For example, some window managers only support resizable windows and will always assume the RESIZE style, even if it is not set.
Styles:
BORDER, CLOSE, MIN, MAX, NO_TRIM, RESIZE, TITLE, ON_TOP, TOOL
Events:
(none)
Class SWT provides two "convenience constants" for the most commonly required style combinations:
SHELL_TRIM
the result of combining the constants which are required to produce a typical application top level shell: (that is, CLOSE | TITLE | MIN | MAX | RESIZE)
DIALOG_TRIM
the result of combining the constants which are required to produce a typical application dialog shell: (that is, TITLE | CLOSE | BORDER)

IMPORTANT: This class is intended to be subclassed only within the SWT implementation.

See Also:
Restriction:
This class is not intended to be subclassed by clients.

  • Constructor Details

    • Decorations

      public Decorations(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

    • dispose

      public void dispose()
      Description copied from class: Widget
      Disposes of the operating system resources associated with the receiver and all its descendants. After this method has been invoked, the receiver and all descendants will answer true when sent the message isDisposed(). Any internal connections between the widgets in the tree will have been removed to facilitate garbage collection. This method does nothing if the widget is already disposed.

      NOTE: This method is not called recursively on the descendants of the receiver. This means that, widget implementers can not detect when a widget is being disposed of by re-implementing this method, but should instead listen for the Dispose event.

      Overrides:
      dispose in class Widget
      See Also:

    • getDefaultButton

      public Button getDefaultButton()
      Returns the receiver's default button if one had previously been set, otherwise returns null.
      Returns:
      the default button or null
      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
      See Also:

    • getImage

      public Image getImage()
      Returns the receiver's image if it had previously been set using setImage(). The image is typically displayed by the window manager when the instance is marked as iconified, and may also be displayed somewhere in the trim when the instance is in normal or maximized states.

      Note: This method will return null if called before setImage() is called. It does not provide access to a window manager provided, "default" image even if one exists.

      Returns:
      the image
      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

    • getImages

      public Image[] getImages()
      Returns the receiver's images if they had previously been set using setImages(). Images are typically displayed by the window manager when the instance is marked as iconified, and may also be displayed somewhere in the trim when the instance is in normal or maximized states. Depending where the icon is displayed, the platform chooses the icon with the "best" attributes. It is expected that the array will contain the same icon rendered at different sizes, with different depth and transparency attributes.

      Note: This method will return an empty array if called before setImages() is called. It does not provide access to a window manager provided, "default" image even if one exists.

      Returns:
      the images
      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:
      3.0

    • getMaximized

      public boolean getMaximized()
      Returns true if the receiver is currently maximized, and false otherwise.
      Returns:
      the maximized state
      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
      See Also:

    • getMenuBar

      public Menu getMenuBar()
      Returns the receiver's menu bar if one had previously been set, otherwise returns null.
      Returns:
      the menu bar or null
      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

    • getMinimized

      public boolean getMinimized()
      Returns true if the receiver is currently minimized, and false otherwise.
      Returns:
      the minimized state
      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
      See Also:

    • getText

      public String getText()
      Returns the receiver's text, which is the string that the window manager will typically display as the receiver's title. If the text has not previously been set, returns an empty string.
      Returns:
      the 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

    • isReparentable

      public boolean isReparentable()
      Description copied from class: Control
      Returns true if the underlying operating system supports this reparenting, otherwise false
      Overrides:
      isReparentable in class Control
      Returns:
      true if the widget can be reparented, otherwise false

    • setDefaultButton

      public void setDefaultButton(Button button)
      If the argument is not null, sets the receiver's default button to the argument, and if the argument is null, sets the receiver's default button to the first button which was set as the receiver's default button (called the saved default button). If no default button had previously been set, or the saved default button was disposed, the receiver's default button will be set to null.

      The default button is the button that is selected when the receiver is active and the user presses ENTER.

      Parameters:
      button - the new default button
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the button has been disposed
      • ERROR_INVALID_PARENT - if the control is not in the same widget tree
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

    • setImage

      public void setImage(Image image)
      Sets the receiver's image to the argument, which may be null. The image is typically displayed by the window manager when the instance is marked as iconified, and may also be displayed somewhere in the trim when the instance is in normal or maximized states.
      Parameters:
      image - the new image (or null)
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the image has been disposed
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

    • setImages

      public void setImages(Image[] images)
      Sets the receiver's images to the argument, which may be an empty array. Images are typically displayed by the window manager when the instance is marked as iconified, and may also be displayed somewhere in the trim when the instance is in normal or maximized states. Depending where the icon is displayed, the platform chooses the icon with the "best" attributes. It is expected that the array will contain the same icon rendered at different sizes, with different depth and transparency attributes.
      Parameters:
      images - the new image array
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the array of images is null
      • ERROR_INVALID_ARGUMENT - if one of the images is null or has been disposed
      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:
      3.0

    • setMaximized

      public void setMaximized(boolean maximized)
      Sets the maximized state of the receiver. If the argument is true causes the receiver to switch to the maximized state, and if the argument is false and the receiver was previously maximized, causes the receiver to switch back to either the minimized or normal states.

      Note: The result of intermixing calls to setMaximized(true) and setMinimized(true) will vary by platform. Typically, the behavior will match the platform user's expectations, but not always. This should be avoided if possible.

      Parameters:
      maximized - the new maximized state
      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
      See Also:

    • setMenuBar

      public void setMenuBar(Menu menu)
      Sets the receiver's menu bar to the argument, which may be null.
      Parameters:
      menu - the new menu bar
      Throws:
      IllegalArgumentException -
      • ERROR_INVALID_ARGUMENT - if the menu has been disposed
      • ERROR_INVALID_PARENT - if the menu is not in the same widget tree
      SWTException -
      • ERROR_WIDGET_DISPOSED - if the receiver has been disposed
      • ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver

    • setMinimized

      public void setMinimized(boolean minimized)
      Sets the minimized stated of the receiver. If the argument is true causes the receiver to switch to the minimized state, and if the argument is false and the receiver was previously minimized, causes the receiver to switch back to either the maximized or normal states.

      Note: The result of intermixing calls to setMaximized(true) and setMinimized(true) will vary by platform. Typically, the behavior will match the platform user's expectations, but not always. This should be avoided if possible.

      Parameters:
      minimized - the new minimized state
      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
      See Also:

    • setOrientation

      public void setOrientation(int orientation)
      Description copied from class: Control
      Sets the orientation of the receiver, which must be one of the constants SWT.LEFT_TO_RIGHT or SWT.RIGHT_TO_LEFT.
      Overrides:
      setOrientation in class Control
      Parameters:
      orientation - new orientation style

    • setText

      public void setText(String string)
      Sets the receiver's text, which is the string that the window manager will typically display as the receiver's title, to the argument, which must not be null.

      Note: If control characters like '\n', '\t' etc. are used in the string, then the behavior is platform dependent.

      Parameters:
      string - the new text
      Throws:
      IllegalArgumentException -
      • ERROR_NULL_ARGUMENT - if the text 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

    • setVisible

      public void setVisible(boolean visible)
      Description copied from class: Control
      Marks the receiver as visible if the argument is true, and marks it invisible otherwise.

      If one of the receiver's ancestors is not visible or some other condition makes the receiver not visible, marking it visible may not actually cause it to be displayed.

      Overrides:
      setVisible in class Control
      Parameters:
      visible - the new visibility state