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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
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*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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*
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package javax.swing.border;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.Component;
import java.io.Serializable;
/**
* A class that implements an empty border with no size.
* This provides a convenient base class from which other border
* classes can be easily derived.
* <p>
* <strong>Warning:</strong>
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeans<sup><font size="-2">TM</font></sup>
* has been added to the <code>java.beans</code> package.
* Please see {@link java.beans.XMLEncoder}.
*
* @author David Kloba
*/
public abstract class AbstractBorder implements Border, Serializable
{
/**
* This default implementation does no painting.
* @param c the component for which this border is being painted
* @param g the paint graphics
* @param x the x position of the painted border
* @param y the y position of the painted border
* @param width the width of the painted border
* @param height the height of the painted border
*/
public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
}
/**
* This default implementation returns a new <code>Insets</code>
* instance where the <code>top</code>, <code>left</code>,
* <code>bottom</code>, and
* <code>right</code> fields are set to <code>0</code>.
* @param c the component for which this border insets value applies
* @return the new <code>Insets</code> object initialized to 0
*/
public Insets getBorderInsets(Component c) {
return new Insets(0, 0, 0, 0);
}
/**
* Reinitializes the insets parameter with this Border's current Insets.
* @param c the component for which this border insets value applies
* @param insets the object to be reinitialized
* @return the <code>insets</code> object
*/
public Insets getBorderInsets(Component c, Insets insets) {
insets.left = insets.top = insets.right = insets.bottom = 0;
return insets;
}
/**
* This default implementation returns false.
* @return false
*/
public boolean isBorderOpaque() { return false; }
/**
* This convenience method calls the static method.
* @param c the component for which this border is being computed
* @param x the x position of the border
* @param y the y position of the border
* @param width the width of the border
* @param height the height of the border
* @return a <code>Rectangle</code> containing the interior coordinates
*/
public Rectangle getInteriorRectangle(Component c, int x, int y, int width, int height) {
return getInteriorRectangle(c, this, x, y, width, height);
}
/**
* Returns a rectangle using the arguments minus the
* insets of the border. This is useful for determining the area
* that components should draw in that will not intersect the border.
* @param c the component for which this border is being computed
* @param b the <code>Border</code> object
* @param x the x position of the border
* @param y the y position of the border
* @param width the width of the border
* @param height the height of the border
* @return a <code>Rectangle</code> containing the interior coordinates
*/
public static Rectangle getInteriorRectangle(Component c, Border b, int x, int y, int width, int height) {
Insets insets;
if(b != null)
insets = b.getBorderInsets(c);
else
insets = new Insets(0, 0, 0, 0);
return new Rectangle(x + insets.left,
y + insets.top,
width - insets.right - insets.left,
height - insets.top - insets.bottom);
}
/**
* Returns the baseline. A return value less than 0 indicates the border
* does not have a reasonable baseline.
* <p>
* The default implementation returns -1. Subclasses that support
* baseline should override appropriately. If a value >= 0 is
* returned, then the component has a valid baseline for any
* size >= the minimum size and <code>getBaselineResizeBehavior</code>
* can be used to determine how the baseline changes with size.
*
* @param c <code>Component</code> baseline is being requested for
* @param width the width to get the baseline for
* @param height the height to get the baseline for
* @return the baseline or < 0 indicating there is no reasonable
* baseline
* @throws IllegalArgumentException if width or height is < 0
* @see java.awt.Component#getBaseline(int,int)
* @see java.awt.Component#getBaselineResizeBehavior()
* @since 1.6
*/
public int getBaseline(Component c, int width, int height) {
if (width < 0 || height < 0) {
throw new IllegalArgumentException(
"Width and height must be >= 0");
}
return -1;
}
/**
* Returns an enum indicating how the baseline of a component
* changes as the size changes. This method is primarily meant for
* layout managers and GUI builders.
* <p>
* The default implementation returns
* <code>BaselineResizeBehavior.OTHER</code>, subclasses that support
* baseline should override appropriately. Subclasses should
* never return <code>null</code>; if the baseline can not be
* calculated return <code>BaselineResizeBehavior.OTHER</code>. Callers
* should first ask for the baseline using
* <code>getBaseline</code> and if a value >= 0 is returned use
* this method. It is acceptable for this method to return a
* value other than <code>BaselineResizeBehavior.OTHER</code> even if
* <code>getBaseline</code> returns a value less than 0.
*
* @param c <code>Component</code> to return baseline resize behavior for
* @return an enum indicating how the baseline changes as the border is
* resized
* @see java.awt.Component#getBaseline(int,int)
* @see java.awt.Component#getBaselineResizeBehavior()
* @since 1.6
*/
public Component.BaselineResizeBehavior getBaselineResizeBehavior(
Component c) {
if (c == null) {
throw new NullPointerException("Component must be non-null");
}
return Component.BaselineResizeBehavior.OTHER;
}
/*
* Convenience function for determining ComponentOrientation.
* Helps us avoid having Munge directives throughout the code.
*/
static boolean isLeftToRight( Component c ) {
return c.getComponentOrientation().isLeftToRight();
}
}