| /* SpringLayout.java -- |
| Copyright (C) 2004 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package javax.swing; |
| |
| import java.awt.Component; |
| import java.awt.Container; |
| import java.awt.Dimension; |
| import java.awt.LayoutManager2; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** |
| * A very flexible layout manager. Components are laid out by defining the |
| * relationships between them. The relationships are expressed as |
| * {@link Spring}s. You can attach a Spring for each edge of a component and |
| * link it to an edge of a different component. For example, you can say, |
| * the northern edge of component A should be attached to the southern edge |
| * of component B, and the space between them should be something between |
| * x and y pixels, and preferably z pixels. |
| * <p>While quite simple, this layout manager can be used to emulate most other |
| * layout managers, and can also be used to solve some layout problems, which |
| * would be hard to solve with other layout managers.</p> |
| * |
| * @author Roman Kennke (roman@ontographics.com) |
| */ |
| public class SpringLayout implements LayoutManager2 |
| { |
| |
| /** The right edge of a component. */ |
| public static final String EAST = "East"; |
| |
| /** The top edge of a component. */ |
| public static final String NORTH = "North"; |
| |
| /** The bottom edge of a component. */ |
| public static final String SOUTH = "South"; |
| |
| /** The left edge of a component. */ |
| public static final String WEST = "West"; |
| |
| /** maps components to their constraints. */ |
| private Map constraintsMap; |
| |
| /** |
| * The constraints that define the relationships between components. |
| * Each Constraints object can hold 4 Springs: one for each edge of the |
| * component. Additionally it can hold Springs for the components width |
| * and the components height. Since the height and width constraints are |
| * dependend on the other constraints, a component can be over-constraint. |
| * In this case (like when all of NORTH, SOUTH and HEIGHT are constraint), |
| * the values are adjusted, so that the mathematics still hold true. |
| * |
| * @author Roman Kennke (roman@ontographics.com) |
| */ |
| public static class Constraints |
| { |
| |
| // The constraints for each edge, and width and height. |
| /** The Spring for the left edge. */ |
| private Spring x; |
| |
| /** The Spring for the upper edge. */ |
| private Spring y; |
| |
| /** The Spring for the height. */ |
| private Spring height; |
| |
| /** The Spring for the width. */ |
| private Spring width; |
| |
| /** The Spring for the right edge. */ |
| private Spring east; |
| |
| /** The Spring for the bottom edge. */ |
| private Spring south; |
| |
| /** |
| * Creates a new Constraints object. |
| * There is no constraint set. |
| */ |
| public Constraints() |
| { |
| x = y = height = width = east = south = null; |
| } |
| |
| /** |
| * Creates a new Constraints object. |
| * |
| * @param x the constraint for the left edge of the component. |
| * @param y the constraint for the upper edge of the component. |
| */ |
| public Constraints(Spring x, Spring y) |
| { |
| this.x = x; |
| this.y = y; |
| width = height = east = south = null; |
| } |
| |
| /** |
| * Creates a new Constraints object. |
| * |
| * @param x the constraint for the left edge of the component. |
| * @param y the constraint for the upper edge of the component. |
| * @param width the constraint for the width of the component. |
| * @param height the constraint for the height of the component. |
| */ |
| public Constraints(Spring x, Spring y, Spring width, Spring height) |
| { |
| this.x = x; |
| this.y = y; |
| this.width = width; |
| this.height = height; |
| east = south = null; |
| } |
| |
| /** |
| * Returns the constraint for the edge with the <code>edgeName</code>. |
| * This is expected to be one of |
| * {@link #EAST}, {@link #WEST}, {@link NORTH} or {@link SOUTH}. |
| * |
| * @param edgeName the name of the edge. |
| * @return the constraint for the specified edge. |
| */ |
| public Spring getConstraint(String edgeName) |
| { |
| Spring retVal = null; |
| if (edgeName.equals(SpringLayout.NORTH)) |
| retVal = y; |
| else if (edgeName.equals(SpringLayout.WEST)) |
| retVal = x; |
| else if (edgeName.equals(SpringLayout.SOUTH)) |
| { |
| retVal = south; |
| if ((retVal == null) && (y != null) && (height != null)) |
| retVal = Spring.sum(y, height); |
| } |
| else if (edgeName.equals(SpringLayout.EAST)) |
| { |
| retVal = east; |
| if ((retVal == null) && (x != null) && (width != null)) |
| retVal = Spring.sum(x, width); |
| } |
| |
| return retVal; |
| } |
| |
| /** |
| * Returns the constraint for the height of the component. |
| * |
| * @return the height constraint. |
| */ |
| public Spring getHeight() |
| { |
| Spring retVal = height; |
| if ((retVal == null) && (y != null) && (south != null)) |
| { |
| retVal = Spring.sum(south, Spring.minus(y)); |
| } |
| return retVal; |
| } |
| |
| /** |
| * Returns the constraint for the width of the component. |
| * |
| * @return the width constraint. |
| */ |
| public Spring getWidth() |
| { |
| Spring retVal = width; |
| if ((retVal == null) && (x != null) && (east != null)) |
| { |
| retVal = Spring.sum(east, Spring.minus(x)); |
| } |
| return retVal; |
| } |
| |
| /** |
| * Returns the constraint for the left edge of the component. |
| * |
| * @return the left-edge constraint (== WEST). |
| */ |
| public Spring getX() |
| { |
| Spring retVal = x; |
| if ((retVal == null) && (width != null) && (east != null)) |
| { |
| retVal = Spring.sum(east, Spring.minus(width)); |
| } |
| return retVal; |
| } |
| |
| /** |
| * Returns the constraint for the upper edge of the component. |
| * |
| * @return the upper-edge constraint (== NORTH). |
| */ |
| public Spring getY() |
| { |
| Spring retVal = y; |
| if ((retVal == null) && (height != null) && (south != null)) |
| { |
| retVal = Spring.sum(south, Spring.minus(height)); |
| } |
| return retVal; |
| } |
| |
| /** |
| * Sets a constraint for the specified edge. If this leads to an |
| * over-constrained situation, the constraints get adjusted, so that |
| * the mathematics still hold true. |
| * |
| * @param edgeName the name of the edge, one of {@link #EAST}, |
| * {@link #WEST}, {@link NORTH} or {@link SOUTH}. |
| * @param s the constraint to be set. |
| */ |
| public void setConstraint(String edgeName, Spring s) |
| { |
| |
| if (edgeName.equals(SpringLayout.WEST)) |
| { |
| x = s; |
| if ((width != null) && (east != null)) |
| width = Spring.sum(east, Spring.minus(x)); |
| } |
| else if (edgeName.equals(SpringLayout.NORTH)) |
| { |
| y = s; |
| if ((height != null) && (south != null)) |
| height = Spring.sum(south, Spring.minus(y)); |
| } |
| else if (edgeName.equals(SpringLayout.EAST)) |
| { |
| east = s; |
| if ((x != null) && (width != null)) |
| x = Spring.sum(east, Spring.minus(width)); |
| } |
| else if (edgeName.equals(SpringLayout.SOUTH)) |
| { |
| south = s; |
| if ((height != null) && (y != null)) |
| y = Spring.sum(south, Spring.minus(height)); |
| } |
| |
| } |
| |
| /** |
| * Sets the height-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setHeight(Spring s) |
| { |
| height = s; |
| if ((south != null) && (y != null)) |
| south = Spring.sum(y, height); |
| |
| } |
| |
| /** |
| * Sets the width-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setWidth(Spring s) |
| { |
| width = s; |
| if ((east != null) && (x != null)) |
| east = Spring.sum(x, width); |
| |
| } |
| |
| /** |
| * Sets the WEST-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setX(Spring s) |
| { |
| x = s; |
| if ((width != null) && (east != null)) |
| width = Spring.sum(east, Spring.minus(x)); |
| |
| } |
| |
| /** |
| * Sets the NORTH-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setY(Spring s) |
| { |
| y = s; |
| if ((height != null) && (south != null)) |
| height = Spring.sum(south, Spring.minus(y)); |
| |
| } |
| } |
| |
| /** |
| * Creates a new SpringLayout. |
| */ |
| public SpringLayout() |
| { |
| |
| constraintsMap = new HashMap(); |
| } |
| |
| /** |
| * Adds a layout component and a constraint object to this layout. |
| * This method is usually only called by a {@java.awt.Container}s add |
| * Method. |
| * |
| * @param component the component to be added. |
| * @param constraint the constraint to be set. |
| */ |
| public void addLayoutComponent(Component component, Object constraint) |
| { |
| constraintsMap.put(component, constraint); |
| } |
| |
| |
| /** |
| * Adds a layout component and a constraint object to this layout. |
| * This method is usually only called by a {@java.awt.Container}s add |
| * Method. This method does nothing, since SpringLayout does not manage |
| * String-indexed components. |
| * |
| * @param component the component to be added. |
| * @param constraint the constraint to be set. |
| */ |
| public void addLayoutComponent(String name, Component c) |
| { |
| // do nothing here. |
| } |
| |
| /** |
| * Returns the constraint of the edge named by <code>edgeName</code>. |
| * |
| * @param c the component from which to get the constraint. |
| * @param edgeName the name of the edge, one of {@link #EAST}, |
| * {@link #WEST}, {@link NORTH} or {@link SOUTH}. |
| * @return the constraint of the edge <code>edgeName</code> of the |
| * component c. |
| */ |
| public Spring getConstraint(String edgeName, Component c) |
| { |
| Constraints constraints = getConstraints(c); |
| return constraints.getConstraint(edgeName); |
| } |
| |
| /** |
| * Returns the {@link Constraints} object associated with the specified |
| * component. |
| * |
| * @param c the component for which to determine the constraint. |
| * @return the {@link Constraints} object associated with the specified |
| * component. |
| */ |
| public SpringLayout.Constraints getConstraints(Component c) |
| { |
| Constraints constraints = (Constraints) constraintsMap.get(c); |
| if (constraints == null) |
| { |
| Container parent = c.getParent(); |
| constraints = new Constraints(); |
| if (parent != null) |
| { |
| constraints.setX |
| (Spring.constant(parent.getInsets().left)); |
| constraints.setY |
| (Spring.constant(parent.getInsets().top)); |
| } |
| else |
| { |
| constraints.setX |
| (Spring.constant(0)); |
| constraints.setY |
| (Spring.constant(0)); |
| |
| } |
| constraints.setWidth |
| (Spring.constant(c.getMinimumSize().width, |
| c.getPreferredSize().width, |
| c.getMaximumSize().width)); |
| constraints.setHeight |
| (Spring.constant(c.getMinimumSize().height, |
| c.getPreferredSize().height, |
| c.getMaximumSize().height)); |
| |
| constraintsMap.put(c, constraints); |
| |
| } |
| |
| return constraints; |
| } |
| |
| /** |
| * Returns the X alignment of the Container <code>p</code>. |
| * |
| * @param p the {@link java.awt.Container} for which to determine the X |
| * alignment. |
| * @return always 0.0 |
| */ |
| public float getLayoutAlignmentX(Container p) |
| { |
| return 0.0F; |
| } |
| |
| /** |
| * Returns the Y alignment of the Container <code>p</code>. |
| * |
| * @param p the {@link java.awt.Container} for which to determine the Y |
| * alignment. |
| * @return always 0.0 |
| */ |
| public float getLayoutAlignmentY(Container p) |
| { |
| return 0.0F; |
| } |
| |
| /** |
| * Recalculate a possibly cached layout. |
| */ |
| public void invalidateLayout(Container p) |
| { |
| // nothing to do here yet |
| } |
| |
| /** |
| * Lays out the container <code>p</code>. |
| * |
| * @param p the container to be laid out. |
| */ |
| public void layoutContainer(Container p) |
| { |
| |
| addLayoutComponent(p, new Constraints(Spring.constant(0), |
| Spring.constant(0))); |
| |
| int offsetX = p.getInsets().left; |
| int offsetY = p.getInsets().right; |
| |
| Component[] components = p.getComponents(); |
| for (int index = 0; index < components.length; index++) |
| { |
| Component c = components[index]; |
| Constraints constraints = getConstraints(c); |
| int x = constraints.getX().getValue(); |
| int y = constraints.getY().getValue(); |
| int width = constraints.getWidth().getValue(); |
| int height = constraints.getHeight().getValue(); |
| |
| c.setLocation(x + offsetX, y + offsetY); |
| c.setSize(width, height); |
| } |
| |
| } |
| |
| /** |
| * Calculates the maximum size of the layed out container. This |
| * respects the maximum sizes of all contained components. |
| * |
| * @param p the container to be laid out. |
| * @return the maximum size of the container. |
| */ |
| public Dimension maximumLayoutSize(Container p) |
| { |
| int maxX = 0; |
| int maxY = 0; |
| |
| int offsetX = p.getInsets().left; |
| int offsetY = p.getInsets().right; |
| |
| Component[] components = p.getComponents(); |
| for (int index = 0; index < components.length; index++) |
| { |
| Component c = components[index]; |
| Constraints constraints = getConstraints(c); |
| int x = constraints.getX().getMaximumValue(); |
| int y = constraints.getY().getMaximumValue(); |
| int width = constraints.getWidth().getMaximumValue(); |
| int height = constraints.getHeight().getMaximumValue(); |
| |
| int rightEdge = offsetX + x + width; |
| if (rightEdge > maxX) |
| maxX = rightEdge; |
| int bottomEdge = offsetY + y + height; |
| if (bottomEdge > maxY) |
| maxY = bottomEdge; |
| } |
| |
| return new Dimension(maxX, maxY); |
| } |
| |
| |
| /** |
| * Calculates the minimum size of the layed out container. This |
| * respects the minimum sizes of all contained components. |
| * |
| * @param p the container to be laid out. |
| * @return the minimum size of the container. |
| */ |
| public Dimension minimumLayoutSize(Container p) |
| { |
| int maxX = 0; |
| int maxY = 0; |
| |
| int offsetX = p.getInsets().left; |
| int offsetY = p.getInsets().right; |
| |
| Component[] components = p.getComponents(); |
| for (int index = 0; index < components.length; index++) |
| { |
| Component c = components[index]; |
| Constraints constraints = getConstraints(c); |
| int x = constraints.getX().getMinimumValue(); |
| int y = constraints.getY().getMinimumValue(); |
| int width = constraints.getWidth().getMinimumValue(); |
| int height = constraints.getHeight().getMinimumValue(); |
| |
| int rightEdge = offsetX + x + width; |
| if (rightEdge > maxX) |
| maxX = rightEdge; |
| int bottomEdge = offsetY + y + height; |
| if (bottomEdge > maxY) |
| maxY = bottomEdge; |
| } |
| |
| return new Dimension(maxX, maxY); |
| } |
| |
| /** |
| * Calculates the preferred size of the layed out container. This |
| * respects the preferred sizes of all contained components. |
| * |
| * @param p the container to be laid out. |
| * @return the preferred size of the container. |
| */ |
| public Dimension preferredLayoutSize(Container p) |
| { |
| int maxX = 0; |
| int maxY = 0; |
| |
| int offsetX = p.getInsets().left; |
| int offsetY = p.getInsets().right; |
| |
| Component[] components = p.getComponents(); |
| for (int index = 0; index < components.length; index++) |
| { |
| Component c = components[index]; |
| Constraints constraints = getConstraints(c); |
| int x = constraints.getX().getPreferredValue(); |
| int y = constraints.getY().getPreferredValue(); |
| int width = constraints.getWidth().getPreferredValue(); |
| int height = constraints.getHeight().getPreferredValue(); |
| |
| int rightEdge = offsetX + x + width; |
| if (rightEdge > maxX) |
| maxX = rightEdge; |
| int bottomEdge = offsetY + y + height; |
| if (bottomEdge > maxY) |
| maxY = bottomEdge; |
| } |
| |
| return new Dimension(maxX, maxY); |
| } |
| |
| /** |
| * Attaches the edge <code>e1</code> of component <code>c1</code> to |
| * the edge <code>e2</code> of component <code>c2</code> width the |
| * fixed strut <code>pad</code>. |
| * |
| * @param e1 the edge of component 1. |
| * @param c1 the component 1. |
| * @param pad the space between the components in pixels. |
| * @param e2 the edge of component 2. |
| * @param c2 the component 2. |
| */ |
| public void putConstraint(String e1, Component c1, int pad, String e2, |
| Component c2) |
| { |
| Constraints constraints1 = getConstraints(c1); |
| Constraints constraints2 = getConstraints(c2); |
| |
| Spring strut = Spring.constant(pad); |
| Spring otherEdge = constraints2.getConstraint(e2); |
| constraints1.setConstraint(e1, Spring.sum(strut, otherEdge)); |
| |
| } |
| |
| /** |
| * Attaches the edge <code>e1</code> of component <code>c1</code> to |
| * the edge <code>e2</code> of component <code>c2</code> width the |
| * {@link Spring} <code>s</code>. |
| * |
| * @param e1 the edge of component 1. |
| * @param c1 the component 1. |
| * @param s the space between the components as a {@link Spring} object. |
| * @param e2 the edge of component 2. |
| * @param c2 the component 2. |
| */ |
| public void putConstraint(String e1, Component c1, Spring s, String e2, |
| Component c2) |
| { |
| Constraints constraints1 = getConstraints(c1); |
| Constraints constraints2 = getConstraints(c2); |
| |
| Spring otherEdge = constraints2.getConstraint(e2); |
| constraints1.setConstraint(e1, Spring.sum(s, otherEdge)); |
| |
| } |
| |
| /** |
| * Removes a layout component. |
| * @param c the layout component to remove. |
| */ |
| public void removeLayoutComponent(Component c) |
| { |
| // do nothing here |
| } |
| } |