HorizBagLayout.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * accompanied this code).
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 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package sun.awt;

import java.awt.*;

/**
 * A horizontal 'bag' of Components.  Allocates space for each Component
 * from left to right.
 *
 * @author      Herb Jellinek
 */
public class HorizBagLayout implements LayoutManager {

    int hgap;

    /**
     * Constructs a new HorizBagLayout.
     */
    public HorizBagLayout() {
        this(0);
    }

    /**
     * Constructs a HorizBagLayout with the specified gaps.
     * @param hgap the horizontal gap
     */
    public HorizBagLayout(int hgap) {
        this.hgap = hgap;
    }

    /**
     * Adds the specified named component to the layout.
     * @param name the String name
     * @param comp the component to be added
     */
    public void addLayoutComponent(String name, Component comp) {
    }

    /**
     * Removes the specified component from the layout.
     * @param comp the component to be removed
     */
    public void removeLayoutComponent(Component comp) {
    }

    /**
     * Returns the minimum dimensions needed to lay out the components
     * contained in the specified target container.
     * @param target the Container on which to do the layout
     * @see Container
     * @see #preferredLayoutSize
     */
    public Dimension minimumLayoutSize(Container target) {
        Dimension dim = new Dimension();

        for (int i = 0; i < target.countComponents(); i++) {
            Component comp = target.getComponent(i);
            if (comp.isVisible()) {
                Dimension d = comp.minimumSize();
                dim.width += d.width + hgap;
                dim.height = Math.max(d.height, dim.height);
            }
        }

        Insets insets = target.insets();
        dim.width += insets.left + insets.right;
        dim.height += insets.top + insets.bottom;

        return dim;
    }

    /**
     * Returns the preferred dimensions for this layout given the components
     * in the specified target container.
     * @param target the component which needs to be laid out
     * @see Container
     * @see #minimumLayoutSize
     */
    public Dimension preferredLayoutSize(Container target) {
        Dimension dim = new Dimension();

        for (int i = 0; i < target.countComponents(); i++) {
            Component comp = target.getComponent(i);
            if (comp.isVisible()) {
                Dimension d = comp.preferredSize();
                dim.width += d.width + hgap;
                dim.height = Math.max(dim.height, d.height);
            }
        }

        Insets insets = target.insets();
        dim.width += insets.left + insets.right;
        dim.height += insets.top + insets.bottom;

        return dim;
    }

    /**
     * Lays out the specified container. This method will actually reshape the
     * components in the specified target container in order to satisfy the
     * constraints of the HorizBagLayout object.
     * @param target the component being laid out
     * @see Container
     */
    public void layoutContainer(Container target) {
        Insets insets = target.insets();
        int top = insets.top;
        int bottom = target.size().height - insets.bottom;
        int left = insets.left;
        int right = target.size().width - insets.right;

        for (int i = 0; i < target.countComponents(); i++) {
            Component comp = target.getComponent(i);
            if (comp.isVisible()) {
                int compWidth = comp.size().width;
                comp.resize(compWidth, bottom - top);
                Dimension d = comp.preferredSize();
                comp.reshape(left, top, d.width, bottom - top);
                left += d.width + hgap;
            }
        }
    }

    /**
     * Returns the String representation of this HorizBagLayout's values.
     */
    public String toString() {
        return getClass().getName() + "[hgap=" + hgap + "]";
    }
}