SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// Multi-Phasic Applications: SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package cc.squirreljme.debugger;

import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Point;
import java.awt.Rectangle;
import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JViewport;
import javax.swing.ScrollPaneConstants;

/**
 * Sequential viewing pane.
 *
 * @since 2024/01/22
 */
public class SequentialPanel
{
    /** The panel to use when returning. */
    protected final JComponent viewPanel;
    
    /** The panel for this pane. */
    protected final JPanel addPanel;
    
    /** Blank filler. */
    protected final JLabel filler =
        new JLabel();
    
    /** Does this have items? */
    private volatile boolean _hasItems;
    
    /**
     * Initializes the panel.
     *
     * @since 2024/01/22
     */
    public SequentialPanel()
    {
        this(true);
    }
    
    /**
     * Initializes the panel.
     *
     * @param __scroll Use a scrolling area for the panel?
     * @since 2024/01/22
     */
    public SequentialPanel(boolean __scroll)
    {
        JPanel panel = new JPanel();
        this.addPanel = panel;
        
        // Use grid bag layout for this
        GridBagLayout layout = new GridBagLayout();
        panel.setLayout(layout);
        
        // Use scrolling area
        if (__scroll)
        {
            // Setup shown area for all the instructions in the method
            JScrollPane scroll = new JScrollPane(panel,
                ScrollPaneConstants.VERTICAL_SCROLLBAR_AS_NEEDED,
                ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
            
            // Scrolling is so horrendously slow...
            scroll.getVerticalScrollBar().setUnitIncrement(
                scroll.getVerticalScrollBar().getUnitIncrement() * 8);
            scroll.setWheelScrollingEnabled(true);
            
            // We want to view the scroll
            this.viewPanel = scroll;
        }
        
        // Do not use a scrolling area
        else
            this.viewPanel = panel;
        
        // Initialize with filler
        panel.add(this.filler);
    }
    
    /**
     * Adds a component to the panel.
     *
     * @param __component The component to add.
     * @throws NullPointerException On null arguments.
     * @since 2024/01/22
     */
    public void add(JComponent __component)
        throws NullPointerException
    {
        if (__component == null)
            throw new NullPointerException("NARG");
        
        GridBagConstraints constraints = new GridBagConstraints();
        constraints.anchor = GridBagConstraints.FIRST_LINE_START;
        constraints.gridx = 0;
        constraints.gridy = GridBagConstraints.RELATIVE;
        constraints.gridwidth = 1;
        constraints.fill = GridBagConstraints.HORIZONTAL;
        
        // Force to the left and take no vertical space
        constraints.weightx = 20.0;
        constraints.weighty = 0.0;
        
        // Remove the filler
        this.addPanel.remove(this.filler);
        
        // Add to the panel
        this.addPanel.add(__component, constraints);
        
        // Add the filler back with an extreme weight
        constraints.weighty = 20.0;
        this.addPanel.add(this.filler, constraints);
        
        // Has items now
        this._hasItems = true;
        
        // Repaint
        Utils.revalidate(this.addPanel);
        Utils.revalidate(this.viewPanel);
    }
    
    /**
     * Does this have any items?
     *
     * @return If this has items or not.
     * @since 2024/01/27
     */
    public boolean hasItems()
    {
        return this._hasItems;
    }
    
    /**
     * Look at the given component.
     *
     * @param __component The component to look at.
     * @throws NullPointerException On null arguments.
     * @since 2024/01/27
     */
    public void lookAt(JComponent __component)
        throws NullPointerException
    {
        if (__component == null)
            throw new NullPointerException("NARG");
        
        // If we are using the scroll pane, we need to focus on this
        JComponent viewPanel = this.viewPanel;
        if (viewPanel instanceof JScrollPane)
        {
            JScrollPane scroll = (JScrollPane)viewPanel;
            JViewport viewport = scroll.getViewport();
            
            // Where is the current view?
            Rectangle viewRect = viewport.getViewRect();
            
            // Scroll here
            Rectangle bounds = __component.getBounds();
            viewport.setViewPosition(new Point(bounds.x,
                bounds.y - (viewRect.height / 4)));
            //viewport.scrollRectToVisible(bounds);
            
            // Make sure the view is updated
            Utils.revalidate(scroll);
        }
    }
    
    /**
     * Returns the used panel for this pane.
     *
     * @return The used panel.
     * @since 2024/01/22
     */
    public JComponent panel()
    {
        return this.viewPanel;
    }
    
    /**
     * Removes all items.
     *
     * @since 2024/01/25
     */
    public void removeAll()
    {
        GridBagConstraints constraints = new GridBagConstraints();
        constraints.anchor = GridBagConstraints.FIRST_LINE_START;
        constraints.gridx = 0;
        constraints.gridy = GridBagConstraints.RELATIVE;
        constraints.gridwidth = 1;
        constraints.fill = GridBagConstraints.HORIZONTAL;
        
        // Clear everything
        this.addPanel.removeAll();
        
        // Add the filler back with an extreme weight
        constraints.weighty = 20.0;
        this.addPanel.add(this.filler, constraints);
        
        // No longer has items
        this._hasItems = false;
        
        // Repaint
        Utils.revalidate(this.addPanel);
        Utils.revalidate(this.viewPanel);
    }
}