GridBagHelper.java

package cz.cuni.lf1.lge.ThunderSTORM.util;

import java.awt.GridBagConstraints;
import java.awt.Insets;

/**
 * A very simple helper class for working with java.awt.GridBagLayout class.
 *
 * When adding control elements (labels, buttons, etc.) into a panel
 * ({@code JPanel}) using the {@code GridBagLayout} it is necessary to provide
 * an instance of {@code GridBagLayoutContraints} class for every single control
 * element to specify its position and size in the grid of
 * {@code GridBagLayout}. And this is exactly what this helper provides. So the
 * whole thing simplifies to:
 * <pre>
 * {@code
 * JPanel panel = new JPanel(new GridBagLayout());
 * panel.add(new JLabel("Hello!"), GridBagHelper.pos(0, 0));}
 * </pre> So the whole call of {@code panel.add} can be in a single line without
 * filling the {@code GridBagConstraints} class every single call.
 */
public class GridBagHelper {

    private static GridBagConstraints gbc = new GridBagConstraints();

    private static GridBagConstraints width(int w, int h) {
        gbc.gridwidth = w;
        gbc.gridheight = h;
        return gbc;
    }

    /**
     * Get a pre-allocated {@code GridBagConstraints} instance filled with X,Y
     * coordinates of a control element in a grid.
     *
     * <strong>Width and height is always set to 1!</strong>
     * For changing the width and/or the height use {@code pos_size} method.
     *
     * @param x X coordinate of a control element in a grid
     * @param y Y coordinate of a control element in a grid
     * @return the pre-allocated instance of{@code GridBagConstraints} class
     * filled with {@code x,y} values specifying the position of a control
     * element in a grid.
     */
    public static GridBagConstraints pos(int x, int y) {
        gbc.gridx = x;
        gbc.gridy = y;
        width(1, 1);
        return gbc;
    }

    /**
     * Get a pre-allocated {@code GridBagConstraints} instance filled with X,Y
     * coordinates, width, and height of a control element in a grid.
     *
     * @param x X coordinate of a control element in a grid
     * @param y Y coordinate of a control element in a grid
     * @param w width of a control element in a grid
     * @param h height of a control element in a grid
     * @return the pre-allocated instance of {@code GridBagConstraints} class
     * filled with {@code x,y} and {@code w,h} values specifying the position,
     * width, and height of a control element in a grid.
     */
    public static GridBagConstraints pos_size(int x, int y, int w, int h) {
        pos(x, y);
        width(w, h);
        return gbc;
    }

    public static GridBagConstraints leftCol() {
        GridBagConstraints ret = new GridBagConstraints();
        ret.gridx = 0;
        ret.weightx = 0.5;
        ret.anchor = GridBagConstraints.LINE_END;
        ret.insets = new Insets(0, 0, 0, 10);
        return ret;
    }

    public static GridBagConstraints rightCol() {
        GridBagConstraints ret = new GridBagConstraints();
        ret.gridx = 1;
        ret.weightx = 0;
        ret.fill = GridBagConstraints.HORIZONTAL;
        ret.anchor = GridBagConstraints.LINE_START;
        return ret;
    }

    public static GridBagConstraints twoCols() {
        GridBagConstraints ret = new GridBagConstraints();
        ret.gridwidth = 2;
        ret.gridx = 0;
        ret.fill = GridBagConstraints.HORIZONTAL;
        ret.anchor = GridBagConstraints.LINE_START;
        return ret;
    }

    public static class Builder {

        GridBagConstraints gbc;

        public Builder() {
            gbc = new GridBagConstraints();
        }

        public Builder(GridBagConstraints gbc) {
            this.gbc = (GridBagConstraints) gbc.clone();
        }

        public GridBagConstraints build() {
            return gbc;
        }

        public Builder gridx(int x) {
            gbc.gridx = x;
            return this;
        }

        public Builder gridy(int y) {
            gbc.gridy = y;
            return this;
        }

        public Builder gridxy(int x, int y) {
            gbc.gridx = x;
            gbc.gridy = y;
            return this;
        }

        public Builder gridwidth(int gridwidth) {
            gbc.gridwidth = gridwidth;
            return this;
        }

        public Builder gridheight(int gridheight) {
            gbc.gridheight = gridheight;
            return this;
        }

        public Builder weightx(double weightx) {
            gbc.weightx = weightx;
            return this;
        }

        public Builder weighty(double weighty) {
            gbc.weighty = weighty;
            return this;
        }

        public Builder fill(int fill) {
            gbc.fill = fill;
            return this;
        }

        public Builder anchor(int anchor) {
            gbc.anchor = anchor;
            return this;
        }

        public Builder insets(Insets insets) {
            gbc.insets = insets;
            return this;
        }

        public Builder ipadx(int ipadx) {
            gbc.ipadx = ipadx;
            return this;
        }

        public Builder ipady(int ipady) {
            gbc.ipady = ipady;
            return this;
        }
    }
}