llvm-gcc-4.2/libjava/classpath/javax/swing/text/ComponentView.java

/* ComponentView.java -- 
   Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
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package javax.swing.text;

import java.awt.Component;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.Shape;

import javax.swing.SwingConstants;
import javax.swing.SwingUtilities;

/**
 * A {@link View} implementation that is able to render arbitrary
 * {@link Component}s. This uses the attribute
 * {@link StyleConstants#ComponentAttribute} to determine the
 * <code>Component</code> that should be rendered. This <code>Component</code>
 * becomes a direct child of the <code>JTextComponent</code> that contains
 * this <code>ComponentView</code>, so this view must not be shared between
 * multiple <code>JTextComponent</code>s.
 *
 * @author Roman Kennke (kennke@aicas.com)
 * @author original author unknown
 */
public class ComponentView extends View
{

  /**
   * The component that is displayed by this view.
   */
  private Component comp;

  /**
   * Creates a new instance of <code>ComponentView</code> for the specified
   * <code>Element</code>.
   *
   * @param elem the element that this <code>View</code> is rendering
   */
  public ComponentView(Element elem)
  {
    super(elem);
  }

  /**
   * Creates the <code>Component</code> that this <code>View</code> is
   * rendering. The <code>Component</code> is determined using
   * the {@link StyleConstants#ComponentAttribute} of the associated
   * <code>Element</code>.
   *
   * @return the component that is rendered
   */
  protected Component createComponent()
  {
    return StyleConstants.getComponent(getElement().getAttributes());
  }

  /**
   * Returns the alignment of this <code>View</code> along the specified axis.
   *
   * @param axis either {@link View#X_AXIS} or {@link View#Y_AXIS}
   *
   * @return the alignment of this <code>View</code> along the specified axis
   */
  public float getAlignment(int axis)
  {
    float align;
    if (axis == X_AXIS)
      align = getComponent().getAlignmentX();
    else if (axis == Y_AXIS)
      align = getComponent().getAlignmentY();
    else
      throw new IllegalArgumentException();
    return align;
  }

  /**
   * Returns the <code>Component</code> that is rendered by this
   * <code>ComponentView</code>.
   *
   * @return the <code>Component</code> that is rendered by this
   *         <code>ComponentView</code>
   */
  public final Component getComponent()
  {
    if (comp == null)
      comp = createComponent();
    return comp;
  }

  /**
   * Returns the maximum span of this <code>View</code> along the specified
   * axis.
   *
   * This will return {@link Component#getMaximumSize()} for the specified
   * axis.
   *
   * @return the maximum span of this <code>View</code> along the specified
   *         axis
   */
  public float getMaximumSpan(int axis)
  {
    float span;
    if (axis == X_AXIS)
      span = getComponent().getMaximumSize().width;
    else if (axis == Y_AXIS)
      span = getComponent().getMaximumSize().height;
    else
      throw new IllegalArgumentException();
    return span;
  }

  public float getMinimumSpan(int axis)
  {
    float span;
    if (axis == X_AXIS)
      span = getComponent().getMinimumSize().width;
    else if (axis == Y_AXIS)
      span = getComponent().getMinimumSize().height;
    else
      throw new IllegalArgumentException();
    return span;
  }

  public float getPreferredSpan(int axis)
  {
    float span;
    if (axis == X_AXIS)
      span = getComponent().getPreferredSize().width;
    else if (axis == Y_AXIS)
      span = getComponent().getPreferredSize().height;
    else
      throw new IllegalArgumentException();
    return span;
  }

  public Shape modelToView(int pos, Shape a, Position.Bias b)
    throws BadLocationException
  {
    Element el = getElement();
    if (pos < el.getStartOffset() || pos >= el.getEndOffset())
      throw new BadLocationException("Illegal offset for this view", pos);
    Rectangle r = a.getBounds();
    Component c = getComponent();
    return new Rectangle(r.x, r.y, c.getWidth(), c.getHeight());
  }

  /**
   * The real painting behavour is performed by normal component painting,
   * triggered by the text component that hosts this view. This method does
   * not paint by itself. However, it sets the size of the component according
   * to the allocation that is passed here.
   *
   * @param g the graphics context
   * @param a the allocation of the child
   */
  public void paint(Graphics g, Shape a)
  {
    Rectangle r = a.getBounds();
    getComponent().setBounds(r.x, r.y, r.width, r.height);
  }

  /**
   * This sets up the component when the view is added to its parent, or
   * cleans up the view when it is removed from its parent.
   *
   * When this view is added to a parent view, the component of this view
   * is added to the container that hosts this view. When <code>p</code> is
   * <code>null</code>, then the view is removed from it's parent and we have
   * to also remove the component from it's parent container.
   *
   * @param p the parent view or <code>null</code> if this view is removed
   *        from it's parent
   */
  public void setParent(final View p)
  {
    if (SwingUtilities.isEventDispatchThread())
      setParentImpl(p);
    else
      SwingUtilities.invokeLater
      (new Runnable()
       {
         public void run()
         {
           setParentImpl(p);
         }
       });
  }

  /**
   * The implementation of {@link #setParent}. This is package private to
   * avoid a synthetic accessor method.
   *
   * @param p the parent view to set
   */
  private void setParentImpl(View p)
  {
    super.setParent(p);
    if (p != null)
      {
        Component c = getComponent();
        p.getContainer().add(c);
      }
    else
      {
        Component c = getComponent();
        Container parent = c.getParent();
        parent.remove(c);
        comp = null;
      }
  }
    
  /**
   * Maps coordinates from the <code>View</code>'s space into a position
   * in the document model.
   *
   * @param x the x coordinate in the view space
   * @param y the y coordinate in the view space
   * @param a the allocation of this <code>View</code>
   * @param b the bias to use
   *
   * @return the position in the document that corresponds to the screen
   *         coordinates <code>x, y</code>
   */
  public int viewToModel(float x, float y, Shape a, Position.Bias[] b)
  {
    // The element should only have one character position and it is clear
    // that this position is the position that best matches the given screen
    // coordinates, simply because this view has only this one position.
    Element el = getElement();
    return el.getStartOffset();
  }
}