File	Doc	Category	Size	Date	Package
OverlayLayout.java	API Doc	Java SE 5 API	8264	Fri Aug 26 14:57:58 BST 2005	javax.swing

OverlayLayout

• java.lang.Object

Fields Summary
private Container	target
private SizeRequirements[]	xChildren
private SizeRequirements[]	yChildren
private SizeRequirements	xTotal
private SizeRequirements	yTotal

Constructors Summary
public OverlayLayout(Container target) Constructs a layout manager that performs overlay arrangement of the children. The layout manager created is dedicated to the given container. param target the container to do layout against this.target = target;

Methods Summary
public void	addLayoutComponent(java.lang.String name, java.awt.Component comp) Adds the specified component to the layout. Used by this class to know when to invalidate layout. param name the name of the component param comp the the component to be added invalidateLayout(comp.getParent());
public void	addLayoutComponent(java.awt.Component comp, java.lang.Object constraints) Adds the specified component to the layout, using the specified constraint object. Used by this class to know when to invalidate layout. param comp the component to be added param constraints where/how the component is added to the layout. invalidateLayout(comp.getParent());
void	checkContainer(java.awt.Container target) if (this.target != target) { throw new AWTError("OverlayLayout can't be shared"); }
void	checkRequests() if (xChildren == null || yChildren == null) { // The requests have been invalidated... recalculate // the request information. int n = target.getComponentCount(); xChildren = new SizeRequirements[n]; yChildren = new SizeRequirements[n]; for (int i = 0; i < n; i++) { Component c = target.getComponent(i); Dimension min = c.getMinimumSize(); Dimension typ = c.getPreferredSize(); Dimension max = c.getMaximumSize(); xChildren[i] = new SizeRequirements(min.width, typ.width, max.width, c.getAlignmentX()); yChildren[i] = new SizeRequirements(min.height, typ.height, max.height, c.getAlignmentY()); } xTotal = SizeRequirements.getAlignedSizeRequirements(xChildren); yTotal = SizeRequirements.getAlignedSizeRequirements(yChildren); }
public float	getLayoutAlignmentX(java.awt.Container target) Returns the alignment along the x axis for the container. param target the container return the alignment >= 0.0f && <= 1.0f checkContainer(target); checkRequests(); return xTotal.alignment;
public float	getLayoutAlignmentY(java.awt.Container target) Returns the alignment along the y axis for the container. param target the container return the alignment >= 0.0f && <= 1.0f checkContainer(target); checkRequests(); return yTotal.alignment;
public void	invalidateLayout(java.awt.Container target) Indicates a child has changed its layout related information, which causes any cached calculations to be flushed. param target the container checkContainer(target); xChildren = null; yChildren = null; xTotal = null; yTotal = null;
public void	layoutContainer(java.awt.Container target) Called by the AWT when the specified container needs to be laid out. param target the container to lay out exception AWTError if the target isn't the container specified to the constructor checkContainer(target); checkRequests(); int nChildren = target.getComponentCount(); int[] xOffsets = new int[nChildren]; int[] xSpans = new int[nChildren]; int[] yOffsets = new int[nChildren]; int[] ySpans = new int[nChildren]; // determine the child placements Dimension alloc = target.getSize(); Insets in = target.getInsets(); alloc.width -= in.left + in.right; alloc.height -= in.top + in.bottom; SizeRequirements.calculateAlignedPositions(alloc.width, xTotal, xChildren, xOffsets, xSpans); SizeRequirements.calculateAlignedPositions(alloc.height, yTotal, yChildren, yOffsets, ySpans); // flush changes to the container for (int i = 0; i < nChildren; i++) { Component c = target.getComponent(i); c.setBounds(in.left + xOffsets[i], in.top + yOffsets[i], xSpans[i], ySpans[i]); }
public java.awt.Dimension	maximumLayoutSize(java.awt.Container target) Returns the maximum dimensions needed to lay out the components contained in the specified target container. Recomputes the layout if it has been invalidated, and factors in the inset setting returned by getInset. param target the component that needs to be laid out return a Dimension object containing the maximum dimensions see #preferredLayoutSize checkContainer(target); checkRequests(); Dimension size = new Dimension(xTotal.maximum, yTotal.maximum); Insets insets = target.getInsets(); size.width += insets.left + insets.right; size.height += insets.top + insets.bottom; return size;
public java.awt.Dimension	minimumLayoutSize(java.awt.Container target) Returns the minimum dimensions needed to lay out the components contained in the specified target container. Recomputes the layout if it has been invalidated, and factors in the current inset setting. param target the component which needs to be laid out return a Dimension object containing the minimum dimensions see #preferredLayoutSize checkContainer(target); checkRequests(); Dimension size = new Dimension(xTotal.minimum, yTotal.minimum); Insets insets = target.getInsets(); size.width += insets.left + insets.right; size.height += insets.top + insets.bottom; return size;
public java.awt.Dimension	preferredLayoutSize(java.awt.Container target) Returns the preferred dimensions for this layout given the components in the specified target container. Recomputes the layout if it has been invalidated. Factors in the current inset setting returned by getInsets(). param target the component which needs to be laid out return a Dimension object containing the preferred dimensions see #minimumLayoutSize checkContainer(target); checkRequests(); Dimension size = new Dimension(xTotal.preferred, yTotal.preferred); Insets insets = target.getInsets(); size.width += insets.left + insets.right; size.height += insets.top + insets.bottom; return size;
public void	removeLayoutComponent(java.awt.Component comp) Removes the specified component from the layout. Used by this class to know when to invalidate layout. param comp the component to remove invalidateLayout(comp.getParent());