| /* SpringLayout.java -- |
| Copyright (C) 2004, 2006, 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., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 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; |
| |
| /** |
| In each axis the user can set three values, i.e. x, width, east, if all |
| three are set, then there's no room for manoeuvre so in those cases the |
| third will be described by the below spring which is calculated in terms |
| of the other two |
| */ |
| private Spring v; |
| private Spring h; |
| |
| /** |
| * Creates a new Constraints object. |
| * There is no constraint set. |
| */ |
| public Constraints() |
| { |
| x = y = height = width = east = south = v = h = 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 = v = h = 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 = v = h = null; |
| } |
| |
| /** |
| * Create a new Constraints object which tracks the indicated |
| * component. The x and y positions for this Constraints object |
| * are constant Springs created with the component's location at |
| * the time this constructor is called. The width and height |
| * of this Constraints are Springs created using |
| * {@link Spring#width(Component)} and {@link Spring#height(Component)}, |
| * respectively. |
| * @param component the component to track |
| * @since 1.5 |
| */ |
| public Constraints(Component component) |
| { |
| this(Spring.constant(component.getX()), |
| Spring.constant(component.getY()), |
| Spring.width(component), |
| Spring.height(component)); |
| } |
| |
| /** |
| * 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 = getY(); |
| else if (edgeName.equals(SpringLayout.WEST)) |
| retVal = getX(); |
| else if (edgeName.equals(SpringLayout.SOUTH)) |
| retVal = getSouth(); |
| else if (edgeName.equals(SpringLayout.EAST)) |
| retVal = getEast(); |
| return retVal; |
| } |
| |
| /** |
| * Returns the constraint for the height of the component. |
| * |
| * @return the height constraint. |
| */ |
| public Spring getHeight() |
| { |
| if (height != null) |
| return height; |
| else if ((v == null) && (y != null) && (south != null)) |
| v = Spring.sum(south, Spring.minus(y)); |
| return v; |
| } |
| |
| /** |
| * Returns the constraint for the width of the component. |
| * |
| * @return the width constraint. |
| */ |
| public Spring getWidth() |
| { |
| if (width != null) |
| return width; |
| else if ((h == null) && (x != null) && (east != null)) |
| h = Spring.sum(east, Spring.minus(x)); |
| return h; |
| } |
| |
| /** |
| * Returns the constraint for the left edge of the component. |
| * |
| * @return the left-edge constraint (== WEST). |
| */ |
| public Spring getX() |
| { |
| if (x != null) |
| return x; |
| else if ((h == null) && (width != null) && (east != null)) |
| h = Spring.sum(east, Spring.minus(width)); |
| return h; |
| } |
| |
| /** |
| * Returns the constraint for the upper edge of the component. |
| * |
| * @return the upper-edge constraint (== NORTH). |
| */ |
| public Spring getY() |
| { |
| if (y != null) |
| return y; |
| else if ((v == null) && (height != null) && (south != null)) |
| v = Spring.sum(south, Spring.minus(height)); |
| return v; |
| } |
| |
| /** |
| * Returns the constraint for the lower edge of the component. |
| * |
| * @return the lower-edge constraint (== SOUTH). |
| */ |
| public Spring getSouth() |
| { |
| if (south != null) |
| return south; |
| else if ((v == null) && (height != null) && (y != null)) |
| v = Spring.sum(y, height); |
| return v; |
| } |
| |
| /** |
| * Returns the constraint for the right edge of the component. |
| * |
| * @return the right-edge constraint (== EAST). |
| */ |
| public Spring getEast() |
| { |
| if (east != null) |
| return east; |
| else if ((h == null) && (width != null) && (x != null)) |
| h = Spring.sum(x, width); |
| return h; |
| } |
| |
| /** |
| * 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)) |
| setX(s); |
| else if (edgeName.equals(SpringLayout.NORTH)) |
| setY(s); |
| else if (edgeName.equals(SpringLayout.EAST)) |
| setEast(s); |
| else if (edgeName.equals(SpringLayout.SOUTH)) |
| setSouth(s); |
| |
| } |
| |
| /** |
| * Sets the height-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setHeight(Spring s) |
| { |
| height = s; |
| v = null; |
| if ((south != null) && (y != null) && (height != null)) |
| south = null; |
| } |
| |
| /** |
| * Sets the width-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setWidth(Spring s) |
| { |
| width = s; |
| h = null; |
| if ((east != null) && (x != null) && (width != null)) |
| east = null; |
| } |
| |
| /** |
| * Sets the WEST-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setX(Spring s) |
| { |
| x = s; |
| h = null; |
| if ((width != null) && (east != null) && (x != null)) |
| width = null; |
| } |
| |
| /** |
| * Sets the NORTH-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setY(Spring s) |
| { |
| y = s; |
| v = null; |
| if ((height != null) && (south != null) && (y != null)) |
| height = null; |
| } |
| |
| /** |
| * Sets the SOUTH-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setSouth(Spring s) |
| { |
| south = s; |
| v = null; |
| if ((height != null) && (south != null) && (y != null)) |
| y = null; |
| } |
| |
| /** |
| * Sets the EAST-constraint. |
| * |
| * @param s the constraint to be set. |
| */ |
| public void setEast(Spring s) |
| { |
| east = s; |
| h = null; |
| if ((width != null) && (east != null) && (x != null)) |
| x = null; |
| } |
| |
| public void dropCalcResult() |
| { |
| if (x != null) |
| x.setValue(Spring.UNSET); |
| if (y != null) |
| y.setValue(Spring.UNSET); |
| if (width != null) |
| width.setValue(Spring.UNSET); |
| if (height != null) |
| height.setValue(Spring.UNSET); |
| if (east != null) |
| east.setValue(Spring.UNSET); |
| if (south != null) |
| south.setValue(Spring.UNSET); |
| if (h != null) |
| h.setValue(Spring.UNSET); |
| if (v != null) |
| v.setValue(Spring.UNSET); |
| } |
| } |
| |
| /** |
| * 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 {@link 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 {@link java.awt.Container}s add |
| * method. This method does nothing, since SpringLayout does not manage |
| * String-indexed components. |
| * |
| * @param name the name. |
| * @param c the component to be added. |
| */ |
| public void addLayoutComponent(String name, Component c) |
| { |
| // do nothing here. |
| } |
| |
| /** |
| * The trick to SpringLayout is that the network of Springs needs to |
| * completely created before the positioning results are generated. |
| * |
| * Using the springs directly during network creation will set their values |
| * before the network is completed, Using Deferred Springs during creation of |
| * the network allows all the edges to be connected together and the network |
| * to be created without resolving the Springs until their results need to be |
| * known, at which point the network is complete and the spring addition and |
| * and substitution calculations will work on a complete and valid network. |
| * |
| * @author Caolan McNamara (caolanm@redhat.com) |
| */ |
| private static class DeferredSpring extends Spring |
| { |
| private SpringLayout sl; |
| private String edgeName; |
| private Component c; |
| |
| public String toString() |
| { |
| return "DeferredSpring of edge" + edgeName + " of " + "something"; |
| } |
| |
| public DeferredSpring(SpringLayout s, String edge, Component component) |
| { |
| sl = s; |
| edgeName = edge; |
| c = component; |
| } |
| |
| private Spring resolveSpring() |
| { |
| return sl.getConstraints(c).getConstraint(edgeName); |
| } |
| |
| public int getMaximumValue() |
| { |
| return resolveSpring().getMaximumValue(); |
| } |
| |
| public int getMinimumValue() |
| { |
| return resolveSpring().getMinimumValue(); |
| } |
| |
| public int getPreferredValue() |
| { |
| return resolveSpring().getPreferredValue(); |
| } |
| |
| public int getValue() |
| { |
| int nRet = resolveSpring().getValue(); |
| if (nRet == Spring.UNSET) |
| nRet = getPreferredValue(); |
| return nRet; |
| } |
| |
| public void setValue(int size) |
| { |
| resolveSpring().setValue(size); |
| } |
| } |
| |
| private abstract static class DeferredDimension extends Spring |
| { |
| private int value; |
| |
| public DeferredDimension() |
| { |
| value = Spring.UNSET; |
| } |
| |
| public void setValue(int val) |
| { |
| value = val; |
| } |
| |
| public int getValue() |
| { |
| if (value == Spring.UNSET) |
| return getPreferredValue(); |
| return value; |
| } |
| } |
| |
| private static class DeferredWidth extends DeferredDimension |
| { |
| private Component c; |
| |
| |
| public DeferredWidth(Component component) |
| { |
| c = component; |
| } |
| |
| public String toString() |
| { |
| return "DeferredWidth of " + "something"; |
| } |
| |
| //clip max to a value we can do meaningful calculation with |
| public int getMaximumValue() |
| { |
| int widget_width = c.getMaximumSize().width; |
| return Math.min(Short.MAX_VALUE, widget_width); |
| } |
| |
| public int getMinimumValue() |
| { |
| return c.getMinimumSize().width; |
| } |
| |
| public int getPreferredValue() |
| { |
| return c.getPreferredSize().width; |
| } |
| } |
| |
| private static class DeferredHeight extends DeferredDimension |
| { |
| private Component c; |
| |
| public String toString() |
| { |
| return "DeferredHeight of " + "something"; |
| } |
| |
| public DeferredHeight(Component component) |
| { |
| c = component; |
| } |
| |
| //clip max to a value we can do meaningful calculations with it |
| public int getMaximumValue() |
| { |
| int widget_height = c.getMaximumSize().height; |
| return Math.min(Short.MAX_VALUE, widget_height); |
| } |
| |
| public int getMinimumValue() |
| { |
| return c.getMinimumSize().height; |
| } |
| |
| public int getPreferredValue() |
| { |
| return c.getPreferredSize().height; |
| } |
| } |
| |
| /** |
| * 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) |
| { |
| return new DeferredSpring(this, edgeName, c); |
| } |
| |
| /** |
| * 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) |
| { |
| constraints = new Constraints(); |
| |
| constraints.setWidth(new DeferredWidth(c)); |
| constraints.setHeight(new DeferredHeight(c)); |
| constraints.setX(Spring.constant(0)); |
| constraints.setY(Spring.constant(0)); |
| |
| 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 |
| } |
| |
| private Constraints initContainer(Container p) |
| { |
| Constraints c = getConstraints(p); |
| |
| c.setX(Spring.constant(0)); |
| c.setY(Spring.constant(0)); |
| c.setWidth(null); |
| c.setHeight(null); |
| if (c.getEast() == null) |
| c.setEast(Spring.constant(0, 0, Integer.MAX_VALUE)); |
| if (c.getSouth() == null) |
| c.setSouth(Spring.constant(0, 0, Integer.MAX_VALUE)); |
| |
| return c; |
| } |
| |
| /** |
| * Lays out the container <code>p</code>. |
| * |
| * @param p the container to be laid out. |
| */ |
| public void layoutContainer(Container p) |
| { |
| java.awt.Insets insets = p.getInsets(); |
| |
| Component[] components = p.getComponents(); |
| |
| Constraints cs = initContainer(p); |
| cs.dropCalcResult(); |
| |
| for (int index = 0 ; index < components.length; index++) |
| { |
| Component c = components[index]; |
| getConstraints(c).dropCalcResult(); |
| } |
| |
| int offsetX = p.getInsets().left; |
| int offsetY = p.getInsets().right; |
| |
| cs.getX().setValue(0); |
| cs.getY().setValue(0); |
| cs.getWidth().setValue(p.getWidth() - offsetX - insets.right); |
| cs.getHeight().setValue(p.getHeight() - offsetY - insets.bottom); |
| |
| 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.setBounds(x + offsetX, y + offsetY, 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) |
| { |
| java.awt.Insets insets = p.getInsets(); |
| |
| Constraints cs = initContainer(p); |
| |
| int maxX = cs.getWidth().getMaximumValue() + insets.left + insets.right; |
| int maxY = cs.getHeight().getMaximumValue() + insets.top + insets.bottom; |
| |
| 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) |
| { |
| java.awt.Insets insets = p.getInsets(); |
| |
| Constraints cs = initContainer(p); |
| |
| int maxX = cs.getWidth().getMinimumValue() + insets.left + insets.right; |
| int maxY = cs.getHeight().getMinimumValue() + insets.top + insets.bottom; |
| |
| 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) |
| { |
| java.awt.Insets insets = p.getInsets(); |
| |
| Constraints cs = initContainer(p); |
| |
| int maxX = cs.getWidth().getPreferredValue() + insets.left + insets.right; |
| int maxY = cs.getHeight().getPreferredValue() + insets.top + insets.bottom; |
| |
| 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) |
| { |
| putConstraint(e1, c1, Spring.constant(pad), e2, c2); |
| } |
| |
| /** |
| * 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); |
| |
| Spring otherEdge = getConstraint(e2, c2); |
| 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 |
| } |
| } |