Package org.eclipse.swt.layout

Class RowLayout

  • public final class RowLayout
extends Layout
    Instances of this class determine the size and position of the children of a Composite by placing them either in horizontal rows or vertical columns within the parent Composite.

    RowLayout aligns all controls in one row if the type is set to horizontal, and one column if it is set to vertical. It has the ability to wrap, and provides configurable margins and spacing. RowLayout has a number of configuration fields. In addition, the height and width of each control in a RowLayout can be specified by setting a RowData object into the control using setLayoutData ().

    The following example code creates a RowLayout, sets all of its fields to non-default values, and then sets it into a Shell. 

        RowLayout rowLayout = new RowLayout();
    rowLayout.wrap = false;
    rowLayout.pack = false;
    rowLayout.justify = true;
    rowLayout.type = SWT.VERTICAL;
    rowLayout.marginLeft = 5;
    rowLayout.marginTop = 5;
    rowLayout.marginRight = 5;
    rowLayout.marginBottom = 5;
    rowLayout.spacing = 0;
    shell.setLayout(rowLayout);
    If you are using the default field values, you only need one line of code: 
        shell.setLayout(new RowLayout());

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

    • Field Summary

      Fields 
      Modifier and Type Field Description
      boolean center
      center specifies whether the controls in a row should be centered vertically in each cell for horizontal layouts, or centered horizontally in each cell for vertical layouts.
      boolean fill
      fill specifies whether the controls in a row should be all the same height for horizontal layouts, or the same width for vertical layouts.
      boolean justify
      justify specifies whether the controls in a row should be fully justified, with any extra space placed between the controls.
      int marginBottom
      marginBottom specifies the number of pixels of vertical margin that will be placed along the bottom edge of the layout.
      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 marginLeft
      marginLeft specifies the number of pixels of horizontal margin that will be placed along the left edge of the layout.
      int marginRight
      marginRight specifies the number of pixels of horizontal margin that will be placed along the right edge of the layout.
      int marginTop
      marginTop specifies the number of pixels of vertical margin that will be placed along the top edge 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.
      boolean pack
      pack specifies whether all controls in the layout take their preferred size.
      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 whether the layout places controls in rows or columns.
      boolean wrap
      wrap specifies whether a control will be wrapped to the next row if there is insufficient space on the current row.

    • Constructor Summary

      Constructors 
      Constructor Description
      RowLayout()
      Constructs a new instance of this class.
      RowLayout​(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 whether the layout places controls in rows or columns. 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 3.

      • wrap

        public boolean wrap
        wrap specifies whether a control will be wrapped to the next row if there is insufficient space on the current row. The default value is true.

      • pack

        public boolean pack
        pack specifies whether all controls in the layout take their preferred size. If pack is false, all controls will have the same size which is the size required to accommodate the largest preferred height and the largest preferred width of all the controls in the layout. The default value is true.

      • fill

        public boolean fill
        fill specifies whether the controls in a row should be all the same height for horizontal layouts, or the same width for vertical layouts. The default value is false.

      • center

        public boolean center
        center specifies whether the controls in a row should be centered vertically in each cell for horizontal layouts, or centered horizontally in each cell for vertical layouts. The default value is false.
        Since:
        1.2

      • justify

        public boolean justify
        justify specifies whether the controls in a row should be fully justified, with any extra space placed between the controls. The default value is false.

      • marginLeft

        public int marginLeft
        marginLeft specifies the number of pixels of horizontal margin that will be placed along the left edge of the layout. The default value is 3.

      • marginTop

        public int marginTop
        marginTop specifies the number of pixels of vertical margin that will be placed along the top edge of the layout. The default value is 3.

      • marginRight

        public int marginRight
        marginRight specifies the number of pixels of horizontal margin that will be placed along the right edge of the layout. The default value is 3.

      • marginBottom

        public int marginBottom
        marginBottom specifies the number of pixels of vertical margin that will be placed along the bottom edge of the layout. The default value is 3.

    • Constructor Detail

      • RowLayout

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

      • RowLayout

        public RowLayout​(int type)
        Constructs a new instance of this class given the type.
        Parameters:
        type - the type of row 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