GridBagBuilder

GridBagBuilder

import java.awt.Component;
import java.awt.Container;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.util.function.Consumer;
/**
 * This greatly streamlines using the GridBagLayout
 * Instantiate with the targeted container as an argument through the static factory forContainer()
 * Then use the "addItem" method to add components. After calling addItem, start chaining the GridBag parameters and then call "finalizeConstraints".
 * @author thomasnield@live.com
 *
 */
public final class GridBagBuilder<T extends Container> {

    private final T container;
    private final GridBagLayout layout;
    private DefaultConstraint defaultConstraint = null;

    public DefaultConstraint setDefaultConstraints() {
        defaultConstraint = new DefaultConstraint();
        return defaultConstraint;
    }

    private DefaultConstraint getDefaultConstraint() {
        return defaultConstraint;
    }

    public static <T extends Container> GridBagBuilder<T> forContainer(T container) {
        return new GridBagBuilder<T>(container);
    }
    private GridBagBuilder(T container)  {
        this.container = container;
        this.layout = new GridBagLayout();
        container.setLayout(this.layout);
    }

    private void addComponent(Component comp)  {
        container.add(comp);
    }

    public <C extends Component> GridItem<C,T> addItem(C comp) {
        return new GridItem<C,T>(comp, this);
    }

    public T buildContainer() {
        return container;
    }


    @SuppressWarnings("serial")
    public class DefaultConstraint extends GridBagConstraints  {
        public DefaultConstraint setFill(FillType fillType)    {
            this.fill = fillType.getCode();
            return this;
        }
        public DefaultConstraint setIPadX(int padding)  {
            this.ipadx = padding;
            return this;
        }
        public DefaultConstraint setIPadY(int padding) {
            this.ipady = padding;
            return this;
        }

        public DefaultConstraint setInsets(int top, int left, int bottom, int right){
            this.insets = new Insets(top,left,bottom,right);
            return this;
        }
        public DefaultConstraint setInsets(int allSidesLength) {
            this.insets = new Insets(allSidesLength,allSidesLength,allSidesLength,allSidesLength);
            return this;
        }
        public DefaultConstraint setAnchor(AnchorType anchorType) {
            this.anchor = anchorType.getCode();
            return this;
        }
    }

    public static final class GridItem<C extends Component, T extends Container>  {
        private final GridBagBuilder<T> parent;
        private final C comp;
        private final GridBagConstraints constraint;

        private GridItem(C comp, GridBagBuilder<T> parent) {
            this.comp = comp;
            this.constraint = new GridBagConstraints();
            this.parent = parent;

            if (parent.getDefaultConstraint() != null) {
                GridBagConstraints defaultConstraint = parent.getDefaultConstraint();

                this.constraint.fill  = defaultConstraint.fill;
                this.constraint.insets = defaultConstraint.insets;
                this.constraint.anchor = defaultConstraint.anchor;
                this.constraint.gridwidth = defaultConstraint.gridwidth;
                this.constraint.gridheight = defaultConstraint.gridheight;
                this.constraint.gridx = defaultConstraint.gridx;
                this.constraint.gridy = defaultConstraint.gridy;
                this.constraint.weightx = defaultConstraint.weightx;
                this.constraint.weighty = defaultConstraint.weighty;

            }

            parent.addComponent(comp);
        }

        public Component getComponent() {
            return comp;
        }


        public GridItem<C,T> setGridX(int x) {
            constraint.gridx = x;
            return this;
        }
        public GridItem<C,T> setGridY(int y) {
            constraint.gridy = y;
            return this;
        }
        public GridItem<C,T> setGridXY(int x, int y) {
            setGridX(x);
            setGridY(y);
            return this;
        }

        public GridItem<C,T> setGridWidth(int xWidth) {
            constraint.gridwidth = xWidth;
            return this;
        }
        public GridItem<C,T> setGridHeight(int yHeight) {
            constraint.gridheight = yHeight;
            return this;
        }

        public GridItem<C,T> setFill(FillType fillType) {
            constraint.fill = fillType.getCode();
            return this;
        }

        public GridItem<C,T> setIPadX(int padding) {
            constraint.ipadx = padding;
            return this;
        }

        public GridItem<C,T>setIPadY(int padding) {
            constraint.ipady = padding;
            return this;
        }

        public GridItem<C,T> setInsets(int top, int left, int bottom, int right) {
            constraint.insets = new Insets(top,left,bottom,right);
            return this;
        }
        public GridItem<C,T> setInsetTop(int top) {
            constraint.insets = getInset();
            constraint.insets.top = top;
            return this;
        }
        public GridItem<C,T> setInsetTopBottom(int value) {
            constraint.insets = getInset();
            constraint.insets.top = value;
            constraint.insets.bottom = value;
            return this;
        }
        public GridItem<C,T> setInsetLeftRight(int value) {
            constraint.insets = getInset();
            constraint.insets.left = value;
            constraint.insets.right = value;
            return this;
        }
        public GridItem<C,T> setInsetBottom(int bottom) {
            constraint.insets = getInset();
            constraint.insets.bottom = bottom;
            return this;
        }
        public GridItem<C,T> setInsetLeft(int left) {
            constraint.insets = getInset();
            constraint.insets.left = left;
            return this;
        }
        public GridItem<C,T> setInsetRight(int right) {
            constraint.insets = getInset();
            constraint.insets.right = right;
            return this;
        }
        private Insets getInset() {
            return constraint.insets == null ? new Insets(0,0,0,0) : constraint.insets;
        }
        public GridItem<C,T> setInsets(int allSidesLength) {
            constraint.insets = new Insets(allSidesLength,allSidesLength,allSidesLength,allSidesLength);
            return this;
        }
        public GridItem<C,T> setAnchor(AnchorType anchorType) {
            constraint.anchor = anchorType.getCode();
            return this;
        }

        public GridItem<C,T> setWeightX(int x) {
            constraint.weightx = x;
            return this;
        }

        public GridItem<C,T> setWeightY(int y) {
            constraint.weighty = y;
            return this;
        }

        public GridItem<C,T> setWeightXY(int x, int y) {
            setWeightX(x);
            setWeightY(y);
            return this;
        }
        /**Perform an operation on the component using a Consumer, handy for adding listeners or formatting*/
        public GridItem<C,T> handle(Consumer<C> consumer) {
            consumer.accept(comp);
            return this;
        }
        public C build() {
            parent.layout.setConstraints(comp, constraint);
            return comp;
        }

    }

    public static enum FillType {
        NONE(GridBagConstraints.NONE),
        HORIZONTAL(GridBagConstraints.HORIZONTAL),
        VERTICAL(GridBagConstraints.VERTICAL),
        BOTH(GridBagConstraints.BOTH);

        private final int code;
        public int getCode() { return code; }

        private FillType(int code) {
            this.code = code;
        }
    }

    public static enum AnchorType {
        NORTHWEST(GridBagConstraints.NORTHWEST),
        WEST(GridBagConstraints.WEST),
        EAST(GridBagConstraints.EAST),
        SOUTHEAST(GridBagConstraints.SOUTHEAST),
        NORTH(GridBagConstraints.NORTH),
        CENTER(GridBagConstraints.CENTER),
        SOUTH(GridBagConstraints.SOUTH),
        NORTHEAST(GridBagConstraints.NORTHEAST),
        SOUTHWEST(GridBagConstraints.SOUTHWEST);

        private final int code;
        public int getCode() {return code; }

        private AnchorType(int code) {
            this.code = code;
        }
    }
}