File	Doc	Category	Size	Date	Package
GraphPaperLayout.java	API Doc	Example	12043	Tue Dec 12 18:59:00 GMT 2000	None

GraphPaperLayout

• java.lang.Object

import java.awt.*;
import java.applet.Applet;
public class ButtonGrid extends Applet {
public void init() {
setLayout(new GraphPaperLayout(new Dimension(5,5)));
// Add a 1x1 Rect at (0,0)
add(new Button("1"), new Rectangle(0,0,1,1));
// Add a 2x1 Rect at (2,0)
add(new Button("2"), new Rectangle(2,0,2,1));
// Add a 1x2 Rect at (1,1)
add(new Button("3"), new Rectangle(1,1,1,2));
// Add a 2x2 Rect at (3,2)
add(new Button("4"), new Rectangle(3,2,2,2));
// Add a 1x1 Rect at (0,4)
add(new Button("5"), new Rectangle(0,4,1,1));
// Add a 1x2 Rect at (2,3)
add(new Button("6"), new Rectangle(2,3,1,2));
}
}

Fields Summary
int	hgap
int	vgap
Dimension	gridSize
Hashtable	compTable

Constructors Summary
public GraphPaperLayout() Creates a graph paper layout with a default of a 1 x 1 graph, with no vertical or horizontal padding. this(new Dimension(1,1));
public GraphPaperLayout(Dimension gridSize) Creates a graph paper layout with the given grid size, with no vertical or horizontal padding. this(gridSize, 0, 0);
public GraphPaperLayout(Dimension gridSize, int hgap, int vgap) Creates a graph paper layout with the given grid size and padding. param gridSize size of the graph paper in logical units (n x m) param hgap horizontal padding param vgap vertical padding if ((gridSize.width <= 0) || (gridSize.height <= 0)) { throw new IllegalArgumentException( "dimensions must be greater than zero"); } this.gridSize = new Dimension(gridSize); this.hgap = hgap; this.vgap = vgap; compTable = new Hashtable();

Methods Summary
public void	addLayoutComponent(java.awt.Component comp, java.lang.Object constraints) Adds the specified component to the layout, using the specified constraint object. param comp the component to be added param constraints where/how the component is added to the layout. if (constraints instanceof Rectangle) { Rectangle rect = (Rectangle)constraints; if ( rect.width <= 0 || rect.height <= 0 ) { throw new IllegalArgumentException( "cannot add to layout: rectangle must have positive width and height"); } if ( rect.x < 0 || rect.y < 0 ) { throw new IllegalArgumentException( "cannot add to layout: rectangle x and y must be >= 0"); } setConstraints(comp, rect); } else if (constraints != null) { throw new IllegalArgumentException( "cannot add to layout: constraint must be a Rectangle"); }
public void	addLayoutComponent(java.lang.String name, java.awt.Component comp) Adds the specified component with the specified name to the layout. This does nothing in GraphPaperLayout, since constraints are required.
public java.awt.Dimension	getGridSize() return the size of the graph paper in logical units (n x m) return new Dimension( gridSize );
protected java.awt.Dimension	getLargestCellSize(java.awt.Container parent, boolean isPreferred) Algorithm for calculating the largest minimum or preferred cell size. Largest cell size is calculated by getting the applicable size of each component and keeping the maximum value, dividing the component's width by the number of columns it is specified to occupy and dividing the component's height by the number of rows it is specified to occupy. param parent the container in which to do the layout. param isPreferred true for calculating preferred size, false for calculating minimum size. return the largest cell size required. int ncomponents = parent.getComponentCount(); Dimension maxCellSize = new Dimension(0,0); for ( int i = 0; i < ncomponents; i++ ) { Component c = parent.getComponent(i); Rectangle rect = (Rectangle)compTable.get(c); if ( c != null && rect != null ) { Dimension componentSize; if ( isPreferred ) { componentSize = c.getPreferredSize(); } else { componentSize = c.getMinimumSize(); } // Note: rect dimensions are already asserted to be > 0 when the // component is added with constraints maxCellSize.width = Math.max(maxCellSize.width, componentSize.width / rect.width); maxCellSize.height = Math.max(maxCellSize.height, componentSize.height / rect.height); } } return maxCellSize;
public float	getLayoutAlignmentX(java.awt.Container target) Returns the alignment along the x axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the furthest away from the origin, 0.5 is centered, etc. return 0.5f;
public float	getLayoutAlignmentY(java.awt.Container target) Returns the alignment along the y axis. This specifies how the component would like to be aligned relative to other components. The value should be a number between 0 and 1 where 0 represents alignment along the origin, 1 is aligned the furthest away from the origin, 0.5 is centered, etc. return 0.5f;
protected java.awt.Dimension	getLayoutSize(java.awt.Container parent, boolean isPreferred) Algorithm for calculating layout size (minimum or preferred). The width of a graph paper layout is the largest cell width (calculated in getLargestCellSize() times the number of columns, plus the horizontal padding times the number of columns plus one, plus the left and right insets of the target container. The height of a graph paper layout is the largest cell height (calculated in getLargestCellSize() times the number of rows, plus the vertical padding times the number of rows plus one, plus the top and bottom insets of the target container. param parent the container in which to do the layout. param isPreferred true for calculating preferred size, false for calculating minimum size. return the dimensions to lay out the subcomponents of the specified container. see java.awt.GraphPaperLayout#getLargestCellSize Dimension largestSize = getLargestCellSize(parent, isPreferred); Insets insets = parent.getInsets(); largestSize.width = ( largestSize.width * gridSize.width ) + ( hgap * ( gridSize.width + 1 ) ) + insets.left + insets.right; largestSize.height = ( largestSize.height * gridSize.height ) + ( vgap * ( gridSize.height + 1 ) ) + insets.top + insets.bottom; return largestSize;
public void	invalidateLayout(java.awt.Container target) Invalidates the layout, indicating that if the layout manager has cached information it should be discarded. // Do nothing
public void	layoutContainer(java.awt.Container parent) Lays out the container in the specified container. param parent the component which needs to be laid out synchronized (parent.getTreeLock()) { Insets insets = parent.getInsets(); int ncomponents = parent.getComponentCount(); if (ncomponents == 0) { return; } // Total parent dimensions Dimension size = parent.getSize(); int totalW = size.width - (insets.left + insets.right); int totalH = size.height - (insets.top + insets.bottom); // Cell dimensions, including padding int totalCellW = totalW / gridSize.width; int totalCellH = totalH / gridSize.height; // Cell dimensions, without padding int cellW = (totalW - ( (gridSize.width + 1) * hgap) ) / gridSize.width; int cellH = (totalH - ( (gridSize.height + 1) * vgap) ) / gridSize.height; for ( int i = 0; i < ncomponents; i++ ) { Component c = parent.getComponent(i); Rectangle rect = (Rectangle)compTable.get(c); if ( rect != null ) { int x = insets.left + ( totalCellW * rect.x ) + hgap; int y = insets.top + ( totalCellH * rect.y ) + vgap; int w = ( cellW * rect.width ) - hgap; int h = ( cellH * rect.height ) - vgap; c.setBounds(x, y, w, h); } } }
public java.awt.Dimension	maximumLayoutSize(java.awt.Container target) Returns the maximum size of this component. see java.awt.Component#getMinimumSize() see java.awt.Component#getPreferredSize() see LayoutManager return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
public java.awt.Dimension	minimumLayoutSize(java.awt.Container parent) Calculates the minimum size dimensions for the specified panel given the components in the specified parent container. param parent the component to be laid out see #preferredLayoutSize return getLayoutSize(parent, false);
public java.awt.Dimension	preferredLayoutSize(java.awt.Container parent) Calculates the preferred size dimensions for the specified panel given the components in the specified parent container. param parent the component to be laid out see #minimumLayoutSize return getLayoutSize(parent, true);
public void	removeLayoutComponent(java.awt.Component comp) Removes the specified component from the layout. param comp the component to be removed compTable.remove(comp);
public void	setConstraints(java.awt.Component comp, java.awt.Rectangle constraints) compTable.put(comp, new Rectangle(constraints));
public void	setGridSize(java.awt.Dimension d) Set the size of the graph paper in logical units (n x m) setGridSize( d.width, d.height );
public void	setGridSize(int width, int height) Set the size of the graph paper in logical units (n x m) gridSize = new Dimension( width, height );