RowHeightResizer.java :  » Database-Client » SQL-Workbench » workbench » gui » components » Java Open Source

/*
 * RowHeightResizer.java
 *
 * This file is part of SQL Workbench/J, http://www.sql-workbench.net
 *
 * Copyright 2002-2008, Thomas Kellerer
 * No part of this code maybe reused without the permission of the author
 *
 * To contact the author please send an email to: support@sql-workbench.net
 *
 */
package workbench.gui.components;

import java.awt.Cursor;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;

import javax.swing.JTable;
import javax.swing.event.MouseInputAdapter;

public class RowHeightResizer
  extends MouseInputAdapter
{
  private JTable table;
  private boolean active;
  private boolean rowSelectionAllowed;
  private int row;
  private int startY;
  private int startHeight;

  private static final int PIXELS = 5;
  private Cursor lastCursor;
  private static Cursor resizeCursor = Cursor.getPredefinedCursor(Cursor.S_RESIZE_CURSOR);

  public RowHeightResizer(JTable table)
  {
    this.table = table;
    this.table.addMouseListener(this);
    this.table.addMouseMotionListener(this);
    this.row = -1;
  }

  public void done()
  {
    if (this.table == null) return;
    this.table.removeMouseListener(this);
    this.table.removeMouseMotionListener(this);
  }

  public void mouseMoved(MouseEvent e)
  {
    Point p = e.getPoint();

    if (this.isMouseOverRowMargin(p))
    {
      if (this.lastCursor == null)
      {
        this.lastCursor = this.table.getCursor();
      }
      this.table.setCursor(resizeCursor);
    }
    else
    {
      this.table.setCursor(this.lastCursor);
    }
  }

  public void mousePressed(MouseEvent e)
  {
    Point p = e.getPoint();

    if (this.isMouseOverRowMargin(p))
    {
      this.active = true;
      this.startY = p.y;
      this.startHeight = table.getRowHeight(row);
      this.rowSelectionAllowed = this.table.getRowSelectionAllowed();
      this.table.setRowSelectionAllowed(false);
    }
  }

  public void mouseDragged(MouseEvent e)
  {
    if (!active) return;

    int newHeight = startHeight + e.getY() - startY;
    newHeight = Math.max(1, newHeight);
    this.table.setRowHeight(row, newHeight);
  }

  public void mouseReleased(MouseEvent e)
  {
    if (!active) return;

    this.table.setRowSelectionAllowed(this.rowSelectionAllowed);
    this.active = false;
    this.row = -1;
  }

  private boolean isMouseOverRowMargin(Point p)
  {
    if (!table.isEnabled()) return false;
    this.row = table.rowAtPoint(p);
    int column = table.columnAtPoint(p);

    if (row == -1 || column == -1) return false;

    Rectangle r = table.getCellRect(row, column, true);

    if (p.y >= r.y + r.height - PIXELS)
    {
      return true;
    }
    return false;
  }

}