Package org.eclipse.swt.layout

Class FillLayout

  • public final class FillLayout
extends Layout
    FillLayout is the simplest layout class. It lays out controls in a single row or column, forcing them to be the same size.

    Initially, the controls will all be as tall as the tallest control, and as wide as the widest. FillLayout does not wrap, but you can specify margins and spacing. You might use it to lay out buttons in a task bar or tool bar, or to stack checkboxes in a Group. FillLayout can also be used when a Composite only has one child. For example, if a Shell has a single Group child, FillLayout will cause the Group to completely fill the Shell (if margins are 0).

    Example code: first a FillLayout is created and its type field is set, and then the layout is set into the Composite. Note that in a FillLayout, children are always the same size, and they fill all available space. 

        FillLayout fillLayout = new FillLayout();
    fillLayout.type = SWT.VERTICAL;
    shell.setLayout(fillLayout);

    Since:
    1.0
    See Also:
    SWT Example: LayoutExample, Sample code and further information

    • Field Summary

      Fields 
      Modifier and Type Field Description
      int marginHeight
      marginHeight specifies the number of pixels of vertical margin that will be placed along the top and bottom edges of the layout.
      int marginWidth
      marginWidth specifies the number of pixels of horizontal margin that will be placed along the left and right edges of the layout.
      int spacing
      spacing specifies the number of pixels between the edge of one cell and the edge of its neighbouring cell.
      int type
      type specifies how controls will be positioned within the layout.

    • Constructor Summary

      Constructors 
      Constructor Description
      FillLayout()
      Constructs a new instance of this class.
      FillLayout​(int type)
      Constructs a new instance of this class given the type.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected Point computeSize​(Composite composite, int wHint, int hHint, boolean flushCache)
      Computes and returns the size of the specified composite's client area according to this layout.
      protected boolean flushCache​(Control control)
      Instruct the layout to flush any cached values associated with the control specified in the argument control.
      protected void layout​(Composite composite, boolean flushCache)
      Lays out the children of the specified composite according to this layout.
      java.lang.String toString()
      Returns a string containing a concise, human-readable description of the receiver.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Field Detail

      • type

        public int type
        type specifies how controls will be positioned within the layout. The default value is HORIZONTAL. Possible values are:
        • HORIZONTAL: Position the controls horizontally from left to right
        • VERTICAL: Position the controls vertically from top to bottom

      • marginWidth

        public int marginWidth
        marginWidth specifies the number of pixels of horizontal margin that will be placed along the left and right edges of the layout. The default value is 0.

      • marginHeight

        public int marginHeight
        marginHeight specifies the number of pixels of vertical margin that will be placed along the top and bottom edges of the layout. The default value is 0.

      • spacing

        public int spacing
        spacing specifies the number of pixels between the edge of one cell and the edge of its neighbouring cell. The default value is 0.

    • Constructor Detail

      • FillLayout

        public FillLayout()
        Constructs a new instance of this class.

      • FillLayout

        public FillLayout​(int type)
        Constructs a new instance of this class given the type.
        Parameters:
        type - the type of fill layout

    • Method Detail

      • computeSize

        protected Point computeSize​(Composite composite,
                            int wHint,
                            int hHint,
                            boolean flushCache)
        Description copied from class: Layout
        Computes and returns the size of the specified composite's client area according to this layout.

        This method computes the size that the client area of the composite must be in order to position all children at their preferred size inside the composite according to the layout algorithm encoded by this layout.

        When a width or height hint is supplied, it is used to constrain the result. For example, if a width hint is provided that is less than the width of the client area, the layout may choose to wrap and increase height, clip, overlap, or otherwise constrain the children.

        Specified by:
        computeSize in class Layout
        Parameters:
        composite - a composite widget using this layout
        wHint - width (SWT.DEFAULT for preferred size)
        hHint - height (SWT.DEFAULT for preferred size)
        flushCache - true means flush cached layout values
        Returns:
        a point containing the computed size (width, height)
        See Also:
        Layout.layout(org.eclipse.swt.widgets.Composite, boolean), Control.getBorderWidth(), Control.getBounds(), Control.getSize(), Control.pack(boolean), "computeTrim, getClientArea for controls that implement them"

      • flushCache

        protected boolean flushCache​(Control control)
        Description copied from class: Layout
        Instruct the layout to flush any cached values associated with the control specified in the argument control.
        Overrides:
        flushCache in class Layout
        Parameters:
        control - a control managed by this layout
        Returns:
        true if the Layout has flushed all cached information associated with control

      • layout

        protected void layout​(Composite composite,
                      boolean flushCache)
        Description copied from class: Layout
        Lays out the children of the specified composite according to this layout.

        This method positions and sizes the children of a composite using the layout algorithm encoded by this layout. Children of the composite are positioned in the client area of the composite. The position of the composite is not altered by this method.

        When the flush cache hint is true, the layout is instructed to flush any cached values associated with the children. Typically, a layout will cache the preferred sizes of the children to avoid the expense of computing these values each time the widget is laid out.

        When layout is triggered explicitly by the programmer the flush cache hint is true. When layout is triggered by a resize, either caused by the programmer or by the user, the hint is false.

        Specified by:
        layout in class Layout
        Parameters:
        composite - a composite widget using this layout
        flushCache - true means flush cached layout values

      • toString

        public java.lang.String toString()
        Returns a string containing a concise, human-readable description of the receiver.
        Overrides:
        toString in class java.lang.Object
        Returns:
        a string representation of the layout