Class Shell

  • All Implemented Interfaces:
    Adaptable, Drawable

    public class Shell
    extends Decorations
    Instances of this class represent the "windows" which the desktop or "window manager" is managing. Instances that do not have a parent (that is, they are built using the constructor, which takes a Display as the argument) are described as top level shells. Instances that do have a parent are described as secondary or dialog shells.

    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.

    The modality of an instance may be specified using style bits. The modality style bits are used to determine whether input is blocked for other shells on the display. The PRIMARY_MODAL style allows an instance to block input to its parent. The APPLICATION_MODAL style allows an instance to block input to every other shell in the display. The SYSTEM_MODAL style allows an instance to block input to all shells, including shells belonging to different applications.

    Note: The styles supported by this class are 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 and modality. For example, some window managers only support resizable windows and will always assume the RESIZE style, even if it is not set. In addition, if a modality style is not supported, it is "upgraded" to a more restrictive modality style that is supported. For example, if PRIMARY_MODAL is not supported, it would be upgraded to APPLICATION_MODAL. A modality style may also be "downgraded" to a less restrictive style. For example, most operating systems no longer support SYSTEM_MODAL because it can freeze up the desktop, so this is typically downgraded to APPLICATION_MODAL.

    Styles:
    BORDER, CLOSE, MIN, MAX, NO_TRIM, RESIZE, TITLE, ON_TOP, TOOL, SHEET
    APPLICATION_MODAL, MODELESS, PRIMARY_MODAL, SYSTEM_MODAL
    Events:
    Activate, Close, Deactivate, Deiconify, Iconify
    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)

    Note: Only one of the styles APPLICATION_MODAL, MODELESS, PRIMARY_MODAL and SYSTEM_MODAL may be specified.

    IMPORTANT: This class is not intended to be subclassed.

    See Also:
    SWT
    • Constructor Detail

      • Shell

        public Shell()
        Constructs a new instance of this class. This is equivalent to calling Shell((Display) null).
        Throws:
        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
        Since:
        1.3
      • Shell

        public Shell​(int style)
        Constructs a new instance of this class given only the style value describing its behavior and appearance. This is equivalent to calling Shell((Display) null, style).

        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:
        style - the style of control to construct
        Throws:
        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.BORDER, SWT.CLOSE, SWT.MIN, SWT.MAX, SWT.RESIZE, SWT.TITLE, SWT.NO_TRIM, SWT.SHELL_TRIM, , SWT.APPLICATION_MODAL, SWT.SHEET
      • Shell

        public Shell​(Display display)
        Constructs a new instance of this class given only the display to create it on. It is created with style SWT.SHELL_TRIM.

        Note: Currently, null can be passed in for the display argument. This has the effect of creating the shell on the currently active display if there is one. If there is no current display, the shell is created on a "default" display. Passing in null as the display argument is not considered to be good coding style, and may not be supported in a future release of SWT.

        Parameters:
        display - the display to create the shell on
        Throws:
        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
      • Shell

        public Shell​(Display display,
                     int style)
        Constructs a new instance of this class given the display to create it on 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.

        Note: Currently, null can be passed in for the display argument. This has the effect of creating the shell on the currently active display if there is one. If there is no current display, the shell is created on a "default" display. Passing in null as the display argument is not considered to be good coding style, and may not be supported in a future release of SWT.

        Parameters:
        display - the display to create the shell on
        style - the style of control to construct
        Throws:
        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.BORDER, SWT.CLOSE, SWT.MIN, SWT.MAX, SWT.RESIZE, SWT.TITLE, SWT.NO_TRIM, SWT.SHELL_TRIM, SWT.DIALOG_TRIM, SWT.MODELESS, SWT.PRIMARY_MODAL, SWT.APPLICATION_MODAL, SWT.SYSTEM_MODAL, SWT.SHEET
      • Shell

        public Shell​(Shell parent)
        Constructs a new instance of this class given only its parent. It is created with style SWT.DIALOG_TRIM.

        Note: Currently, null can be passed in for the parent. This has the effect of creating the shell on the currently active display if there is one. If there is no current display, the shell is created on a "default" display. Passing in null as the parent is not considered to be good coding style, and may not be supported in a future release of SWT.

        Parameters:
        parent - a shell which will be the parent of the new instance
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the parent is disposed
        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
      • Shell

        public Shell​(Shell 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.

        Note: Currently, null can be passed in for the parent. This has the effect of creating the shell on the currently active display if there is one. If there is no current display, the shell is created on a "default" display. Passing in null as the parent is not considered to be good coding style, and may not be supported in a future release of SWT.

        Parameters:
        parent - a shell which will be the parent of the new instance
        style - the style of control to construct
        Throws:
        java.lang.IllegalArgumentException -
        • ERROR_INVALID_ARGUMENT - if the parent is disposed
        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.BORDER, SWT.CLOSE, SWT.MIN, SWT.MAX, SWT.RESIZE, SWT.TITLE, SWT.NO_TRIM, SWT.SHELL_TRIM, SWT.DIALOG_TRIM, SWT.ON_TOP, SWT.TOOL, , SWT.APPLICATION_MODAL
    • Method Detail

      • getShells

        public Shell[] getShells()
        Returns an array containing all shells which are descendents of the receiver.

        Returns:
        the dialog shells
        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
      • 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:
        Scrollable.getClientArea()
      • getBorderWidth

        public int getBorderWidth()
        Description copied from class: Control
        Returns the receiver's border width. Note: When the theming defines different border widths for the four edges, this method returns the maximum border width.
        Overrides:
        getBorderWidth in class Control
        Returns:
        the border width
      • getAdapter

        public <T> T getAdapter​(java.lang.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 Decorations
        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.
      • setEnabled

        public void setEnabled​(boolean enabled)
        Description copied from class: Control
        Enables the receiver if the argument is true, and disables it otherwise. A disabled control is typically not selectable from the user interface and draws with an inactive or "grayed" look.
        Overrides:
        setEnabled in class Control
        Parameters:
        enabled - the new enabled state
      • isEnabled

        public boolean isEnabled()
        Description copied from class: Control
        Returns true if the receiver is enabled and all ancestors up to and including the receiver's nearest ancestor shell are enabled. Otherwise, false is returned. A disabled control is typically not selectable from the user interface and draws with an inactive or "grayed" look.
        Overrides:
        isEnabled in class Control
        Returns:
        the receiver's enabled state
        See Also:
        Control.getEnabled()
      • isVisible

        public boolean isVisible()
        Description copied from class: Control
        Returns true if the receiver is visible and all ancestors up to and including the receiver's nearest ancestor shell are visible. Otherwise, false is returned.
        Overrides:
        isVisible in class Control
        Returns:
        the receiver's visibility state
        See Also:
        Control.getVisible()
      • 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
      • close

        public void close()
        Requests that the window manager close the receiver in the same way it would be closed when the user clicks on the "close box" or performs some other platform specific key or mouse combination that indicates the window should be removed.
        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:
        SWT.Close, Widget.dispose()
      • setAlpha

        public void setAlpha​(int alpha)
        Sets the receiver's alpha value.

        This operation may not be available on some platforms.

        Parameters:
        alpha - the alpha 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:
        1.1
      • getAlpha

        public int getAlpha()
        Returns the receiver's alpha value.
        Returns:
        the alpha 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:
        1.1
      • setModified

        public void setModified​(boolean modified)
        Sets the receiver's modified state as specified by the argument.
        Parameters:
        modified - the new modified state for the receiver
      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
    • getModified

      public boolean getModified()
      Gets the receiver's modified 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
Since:
1.3