OAC-Swing/src/main/java/org/openautonomousconnection/oacswing/component/OACTabbedPane.java

/* Author: Maple
 *  Feb. 2 2026
 *  */

package org.openautonomousconnection.oacswing.component;

import lombok.NonNull;
import org.openautonomousconnection.oacswing.component.design.DesignManager;

import javax.swing.*;
import javax.swing.plaf.basic.BasicTabbedPaneUI;
import java.awt.*;

public class OACTabbedPane extends JTabbedPane implements OACComponent {
    private boolean selectionSyncInstalled;

    public OACTabbedPane() {
        super();
    }

    public OACTabbedPane(int tabPlacement) {
        super(tabPlacement);
    }

    public OACTabbedPane(int tabPlacement, int tabLayoutPolicy) {
        super(tabPlacement, tabLayoutPolicy);
    }

    @Override
    public void init() {
        applyDesignColors();
    }

    @Override
    public void updateUI() {
        super.updateUI();
        applyDesignColors();
    }

    private void applyDesignColors() {
        Color bg = DesignManager.resolveBackground(OACTabbedPane.class, getBackground());
        Color fg = DesignManager.resolveForeground(OACTabbedPane.class, getForeground());
        Color selectedBg = DesignManager.resolveHovered(OACButton.class, bg.darker());
        Color selectedFg = fg;
        Color border = DesignManager.resolveBorderColor(bg.darker());

        setOpaque(true);
        setBackground(bg);
        setForeground(fg);
        setUI(new DesignTabbedPaneUI(bg, selectedBg, border));
        applyTabItemColors(bg, fg, selectedBg, selectedFg);
        installSelectionSyncIfNeeded();
    }

    private void applyTabItemColors(Color bg, Color fg, Color selectedBg, Color selectedFg) {
        int selectedIndex = getSelectedIndex();
        for (int i = 0; i < getTabCount(); i++) {
            boolean selected = i == selectedIndex;
            setBackgroundAt(i, selected ? selectedBg : bg);
            setForegroundAt(i, selected ? selectedFg : fg);
        }
        repaint();
    }

    private void installSelectionSyncIfNeeded() {
        if (selectionSyncInstalled) {
            return;
        }
        addChangeListener(e -> {
            Color bg = DesignManager.resolveBackground(OACTabbedPane.class, getBackground());
            Color fg = DesignManager.resolveForeground(OACTabbedPane.class, getForeground());
            Color selectedBg = DesignManager.resolveHovered(OACButton.class, bg.darker());
            applyTabItemColors(bg, fg, selectedBg, fg);
        });
        selectionSyncInstalled = true;
    }

    private static final class DesignTabbedPaneUI extends BasicTabbedPaneUI {
        private final Color background;
        private final Color selectedBackground;
        private final Color borderColor;

        private DesignTabbedPaneUI(Color background, Color selectedBackground, Color borderColor) {
            this.background = background;
            this.selectedBackground = selectedBackground;
            this.borderColor = borderColor;
        }

        @Override
        protected void paintTabBackground(Graphics g, int tabPlacement, int tabIndex,
                                          int x, int y, int w, int h, boolean isSelected) {
            g.setColor(isSelected ? selectedBackground : background);
            g.fillRect(x, y, w, h);
        }

        @Override
        protected void paintTabBorder(Graphics g, int tabPlacement, int tabIndex,
                                      int x, int y, int w, int h, boolean isSelected) {
            g.setColor(borderColor);
            g.drawRect(x, y, w, h);
        }

        @Override
        protected void paintFocusIndicator(Graphics g, int tabPlacement, Rectangle[] rects,
                                           int tabIndex, Rectangle iconRect, Rectangle textRect, boolean isSelected) {
            // no-op to avoid bright LAF focus ring
        }

        @Override
        protected void paintContentBorder(Graphics g, int tabPlacement, int selectedIndex) {
            int width = tabPane.getWidth();
            int height = tabPane.getHeight();
            Insets insets = tabPane.getInsets();

            int x = insets.left;
            int y = insets.top;
            int w = width - insets.right - insets.left;
            int h = height - insets.top - insets.bottom;

            switch (tabPlacement) {
                case LEFT -> {
                    x += calculateTabAreaWidth(tabPlacement, runCount, maxTabWidth);
                    w -= (x - insets.left);
                }
                case RIGHT -> w -= calculateTabAreaWidth(tabPlacement, runCount, maxTabWidth);
                case BOTTOM -> h -= calculateTabAreaHeight(tabPlacement, runCount, maxTabHeight);
                default -> {
                    y += calculateTabAreaHeight(tabPlacement, runCount, maxTabHeight);
                    h -= (y - insets.top);
                }
            }

            g.setColor(background);
            g.fillRect(x, y, w, h);
            g.setColor(borderColor);
            g.drawRect(x, y, Math.max(0, w - 1), Math.max(0, h - 1));
        }
    }

    @Override
    public void addTab(String title, Component component) {
        this.initOther(component);
        super.addTab(title, component);
        applyDesignColors();
    }

    @Override
    public void addTab(String title, Icon icon, Component component) {
        this.initOther(component);
        super.addTab(title, icon, component);
        applyDesignColors();
    }

    @Override
    public void addTab(String title, Icon icon, Component component, String tip) {
        this.initOther(component);
        super.addTab(title, icon, component, tip);
        applyDesignColors();
    }

    @Override
    public Component add(Component comp) {
        this.initOther(comp);
        return super.add(comp);
    }

    @Override
    public Component add(Component comp, int index) {
        this.initOther(comp);
        return super.add(comp, index);
    }

    @Override
    public void add(@NonNull Component comp, Object constraints) {
        this.initOther(comp);
        super.add(comp, constraints);
    }

    @Override
    public Component add(String name, Component comp) {
        this.initOther(comp);
        return super.add(name, comp);
    }

    @Override
    public void add(Component comp, Object constraints, int index) {
        this.initOther(comp);
        super.add(comp, constraints, index);
    }
}