This improves the BasicLabelUI:
- It caches the Insets instance.
- It makes the font metrics fetching more fail-safe.
- It removes the graphics color restoring, this is already performed by
Swing's painting mechanism.
2007-04-03 Roman Kennke <[EMAIL PROTECTED]>
* javax/swing/plaf/basic/BasicLabelUI.java
(cachedInsets): New field. Used for reusing the insets instance.
(getFontMetrics): New helper method for fetching a suitable
FontMetrics object.
(getPreferredSize): Use new helper method for font metrics.
(paint): Only do something if we have an icon or text.
Use cached Insets instance and new font metrics helper.
(paintDisabledText): Don't restore the graphics' color.
(paintEnabledText): Don't restore the graphics' color.
/Roman
--
http://kennke.org/blog/
Index: javax/swing/plaf/basic/BasicLabelUI.java
===================================================================
RCS file: /cvsroot/classpath/classpath/javax/swing/plaf/basic/BasicLabelUI.java,v
retrieving revision 1.25
diff -u -1 -5 -r1.25 BasicLabelUI.java
--- javax/swing/plaf/basic/BasicLabelUI.java 17 Aug 2006 14:45:46 -0000 1.25
+++ javax/swing/plaf/basic/BasicLabelUI.java 3 Apr 2007 20:33:19 -0000
@@ -25,73 +25,80 @@
As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module. An independent module is a module which is not derived from
or based on this library. If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so. If you do not wish to do so, delete this
exception statement from your version. */
package javax.swing.plaf.basic;
-import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
+import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.Rectangle;
+import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.Icon;
import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.KeyStroke;
import javax.swing.LookAndFeel;
import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.LabelUI;
import javax.swing.text.View;
/**
* This is the Basic Look and Feel class for the JLabel. One BasicLabelUI
* object is used to paint all JLabels that utilize the Basic Look and Feel.
*/
public class BasicLabelUI extends LabelUI implements PropertyChangeListener
{
/** The labelUI that is shared by all labels. */
protected static BasicLabelUI labelUI;
/**
* These fields hold the rectangles for the whole label,
* the icon and the text.
*/
private Rectangle vr;
private Rectangle ir;
private Rectangle tr;
/**
+ * A cached Insets object for reuse in the label layout methods.
+ */
+ private Insets cachedInsets;
+
+ /**
* Creates a new BasicLabelUI object.
*/
public BasicLabelUI()
{
super();
vr = new Rectangle();
ir = new Rectangle();
tr = new Rectangle();
}
/**
* Creates and returns a UI for the label. Since one UI is shared by all
* labels, this means creating only if necessary and returning the shared
* UI.
*
@@ -119,31 +126,31 @@
{
JLabel lab = (JLabel) c;
Insets insets = lab.getInsets();
int insetsX = insets.left + insets.right;
int insetsY = insets.top + insets.bottom;
Icon icon = lab.getIcon();
String text = lab.getText();
Dimension ret;
if (icon == null && text == null)
ret = new Dimension(insetsX, insetsY);
else if (icon != null && text == null)
ret = new Dimension(icon.getIconWidth() + insetsX,
icon.getIconHeight() + insetsY);
else
{
- FontMetrics fm = lab.getFontMetrics(lab.getFont());
+ FontMetrics fm = getFontMetrics(lab);
ir.x = 0;
ir.y = 0;
ir.width = 0;
ir.height = 0;
tr.x = 0;
tr.y = 0;
tr.width = 0;
tr.height = 0;
vr.x = 0;
vr.y = 0;
vr.width = Short.MAX_VALUE;
vr.height = Short.MAX_VALUE;
layoutCL(lab, fm, text, icon, vr, ir, tr);
Rectangle cr = SwingUtilities.computeUnion(tr.x, tr.y, tr.width,
tr.height, ir);
@@ -177,67 +184,70 @@
*/
public Dimension getMaximumSize(JComponent c)
{
return getPreferredSize(c);
}
/**
* The method that paints the label according to its current state.
*
* @param g The [EMAIL PROTECTED] Graphics} object to paint with.
* @param c The [EMAIL PROTECTED] JComponent} to paint.
*/
public void paint(Graphics g, JComponent c)
{
JLabel b = (JLabel) c;
- FontMetrics fm = g.getFontMetrics();
-
- Insets i = c.getInsets();
- vr.x = i.left;
- vr.y = i.right;
- vr.width = c.getWidth() - i.left + i.right;
- vr.height = c.getHeight() - i.top + i.bottom;
- ir.x = 0;
- ir.y = 0;
- ir.width = 0;
- ir.height = 0;
- tr.x = 0;
- tr.y = 0;
- tr.width = 0;
- tr.height = 0;
Icon icon = (b.isEnabled()) ? b.getIcon() : b.getDisabledIcon();
+ String text = b.getText();
+ if (icon != null || (text != null && ! text.equals("")))
+ {
+ FontMetrics fm = getFontMetrics(b);
+ Insets i = c.getInsets(cachedInsets);
+ vr.x = i.left;
+ vr.y = i.right;
+ vr.width = c.getWidth() - i.left - i.right;
+ vr.height = c.getHeight() - i.top - i.bottom;
+ ir.x = 0;
+ ir.y = 0;
+ ir.width = 0;
+ ir.height = 0;
+ tr.x = 0;
+ tr.y = 0;
+ tr.width = 0;
+ tr.height = 0;
- String text = layoutCL(b, fm, b.getText(), icon, vr, ir, tr);
+ text = layoutCL(b, fm, text, icon, vr, ir, tr);
- if (icon != null)
- icon.paintIcon(b, g, ir.x, ir.y);
+ if (icon != null)
+ icon.paintIcon(b, g, ir.x, ir.y);
- Object htmlRenderer = b.getClientProperty(BasicHTML.propertyKey);
- if (htmlRenderer == null)
- {
- if (text != null && !text.equals(""))
+ if (text != null && ! text.equals(""))
{
- if (b.isEnabled())
- paintEnabledText(b, g, text, tr.x, tr.y + fm.getAscent());
+ Object htmlRenderer = b.getClientProperty(BasicHTML.propertyKey);
+ if (htmlRenderer == null)
+ {
+ if (b.isEnabled())
+ paintEnabledText(b, g, text, tr.x, tr.y + fm.getAscent());
+ else
+ paintDisabledText(b, g, text, tr.x, tr.y + fm.getAscent());
+ }
else
- paintDisabledText(b, g, text, tr.x, tr.y + fm.getAscent());
+ {
+ ((View) htmlRenderer).paint(g, tr);
+ }
}
}
- else
- {
- ((View) htmlRenderer).paint(g, tr);
- }
}
/**
* This method is simply calls SwingUtilities's layoutCompoundLabel.
*
* @param label The label to lay out.
* @param fontMetrics The FontMetrics for the font used.
* @param text The text to paint.
* @param icon The icon to draw.
* @param viewR The entire viewable rectangle.
* @param iconR The icon bounds rectangle.
* @param textR The text bounds rectangle.
*
* @return A possibly clipped version of the text.
*/
@@ -253,77 +263,70 @@
/**
* Paints the text if the label is disabled. By default, this paints the
* clipped text returned by layoutCompoundLabel using the
* background.brighter() color. It also paints the same text using the
* background.darker() color one pixel to the right and one pixel down.
*
* @param l The [EMAIL PROTECTED] JLabel} being painted.
* @param g The [EMAIL PROTECTED] Graphics} object to paint with.
* @param s The String to paint.
* @param textX The x coordinate of the start of the baseline.
* @param textY The y coordinate of the start of the baseline.
*/
protected void paintDisabledText(JLabel l, Graphics g, String s, int textX,
int textY)
{
- Color saved_color = g.getColor();
-
g.setColor(l.getBackground().brighter());
int mnemIndex = l.getDisplayedMnemonicIndex();
if (mnemIndex != -1)
BasicGraphicsUtils.drawStringUnderlineCharAt(g, s, mnemIndex, textX,
textY);
else
g.drawString(s, textX, textY);
g.setColor(l.getBackground().darker());
if (mnemIndex != -1)
BasicGraphicsUtils.drawStringUnderlineCharAt(g, s, mnemIndex, textX + 1,
textY + 1);
else
g.drawString(s, textX + 1, textY + 1);
-
- g.setColor(saved_color);
}
/**
* Paints the text if the label is enabled. The text is painted using the
* foreground color.
*
* @param l The [EMAIL PROTECTED] JLabel} being painted.
* @param g The [EMAIL PROTECTED] Graphics} object to paint with.
* @param s The String to paint.
* @param textX The x coordinate of the start of the baseline.
* @param textY The y coordinate of the start of the baseline.
*/
protected void paintEnabledText(JLabel l, Graphics g, String s, int textX,
- int textY)
+ int textY)
{
- Color saved_color = g.getColor();
g.setColor(l.getForeground());
int mnemIndex = l.getDisplayedMnemonicIndex();
if (mnemIndex != -1)
BasicGraphicsUtils.drawStringUnderlineCharAt(g, s, mnemIndex, textX,
textY);
else
g.drawString(s, textX, textY);
-
- g.setColor(saved_color);
}
/**
* This method installs the UI for the given [EMAIL PROTECTED] JComponent}. This
* method will install the component, defaults, listeners, and keyboard
* actions.
*
* @param c The [EMAIL PROTECTED] JComponent} that this UI is being installed on.
*/
public void installUI(JComponent c)
{
super.installUI(c);
if (c instanceof JLabel)
{
JLabel l = (JLabel) c;
@@ -502,16 +505,39 @@
KeyEvent.ALT_DOWN_MASK), null);
keyMap.put(KeyStroke.getKeyStroke(newMnemonic,
KeyEvent.ALT_DOWN_MASK), "press");
}
}
else if (e.getPropertyName().equals("labelFor"))
{
JLabel label = (JLabel) e.getSource();
InputMap keyMap = label.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
int mnemonic = label.getDisplayedMnemonic();
if (mnemonic > 0)
keyMap.put(KeyStroke.getKeyStroke(mnemonic, KeyEvent.ALT_DOWN_MASK),
"press");
}
}
+
+ /**
+ * Fetches a font metrics object for the specified label. This first
+ * tries to get it from the label object itself by calling
+ * [EMAIL PROTECTED] Component#getFontMetrics(Font)}, and if that does not work
+ * (for instance, when we are in the initialization and have no parent yet),
+ * it asks the Toolkit for a font metrics object.
+ *
+ * @param l the label
+ *
+ * @return a suitable font metrics object
+ */
+ private FontMetrics getFontMetrics(JLabel l)
+ {
+ Font font = l.getFont();
+ FontMetrics fm = l.getFontMetrics(font);
+ if (fm == null)
+ {
+ Toolkit tk = Toolkit.getDefaultToolkit();
+ fm = tk.getFontMetrics(font);
+ }
+ return fm;
+ }
}
