我正在开发一个试图缩放通用窗口（JFrame或JDialog）的应用程序。
我发现了一个问题，当要放大JSlider组件时，即使Component本身的边界已经改变，视觉指针JSlider也不会缩放。
我在JSlider公共API中查找了一个函数，该函数返回一个基类Component的对象，可以修改，但我还没有找到。
函数jSlider1.getComponentCount()也返回0.
如果那里有合适的功能，我也会查看SliderUI课程，但没有成功
有谁知道访问Component的视觉指针JSlider的正确方法？或者至少如何设置它的大小，以便能够缩放它？
答案 0 :(得分：1)
正如我之前在评论中所说，我最终决定覆盖JSlider和MetalSliderUI类。 至少这与Java-8兼容，因为我开始的代码是oracle JDK-8。
使用新类的示例的代码如下。
新界面：
public interface ZoomInterface
{
public void setZoomFactor( double zoomFactor );
public double getZoomFactor();
}
New overriden classes:
ZoomMetalSliderUI:
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import javax.swing.Icon;
import javax.swing.JComponent;
import javax.swing.JSlider;
import javax.swing.plaf.metal.MetalLookAndFeel;
import javax.swing.plaf.metal.MetalSliderUI;
/**
*
* @author Francisco Javier Rojas Garrido <frojasg1@hotmail.com>
*/
public class ZoomMetalSliderUI extends MetalSliderUI implements ZoomInterface
{
protected double _zoomFactor = 1.0D;
public ZoomMetalSliderUI()
{
super();
}
@Override
public Dimension getThumbSize()
{
Dimension result = ViewFunctions.instance().getNewDimension( super.getThumbSize(), null, _zoomFactor );
return( result );
}
@Override
public void setZoomFactor(double zoomFactor)
{
_zoomFactor = zoomFactor;
}
@Override
public double getZoomFactor()
{
return( _zoomFactor );
}
@Override
public void paint( Graphics g, JComponent c )
{
calculateGeometry();
super.paint(g, c);
}
@Override
public void paintThumb(Graphics g) {
Rectangle knobBounds = thumbRect;
// g.translate( knobBounds.x, knobBounds.y );
Icon icon = null;
if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
icon = horizThumbIcon;
}
else {
icon = vertThumbIcon;
}
BufferedImage bi = new BufferedImage( icon.getIconWidth(), icon.getIconHeight(),
BufferedImage.TYPE_INT_ARGB );
Graphics g1 = bi.getGraphics();
if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
horizThumbIcon.paintIcon( slider, bi.getGraphics(), 0, 0 );
}
else {
vertThumbIcon.paintIcon( slider, bi.getGraphics(), 0, 0 );
}
Rectangle tr = new Rectangle( 0, 0, icon.getIconWidth(), icon.getIconHeight() );
Rectangle newRectangle = ViewFunctions.instance().getNewRectangle(tr, null, _zoomFactor );
BufferedImage bi_tx = ImageFunctions.resizeImage(bi, (int)newRectangle.getWidth(),
(int)newRectangle.getHeight(),
null, null, null );
Point center = ViewFunctions.instance().getCenter(knobBounds);
g.drawImage( bi_tx, center.x - newRectangle.width / 2,
center.y - newRectangle.height / 2,
center.x + newRectangle.width / 2,
center.y + newRectangle.height / 2,
0,
0,
bi_tx.getWidth(),
bi_tx.getHeight(),
null );
// g.translate( -knobBounds.x, -knobBounds.y );
}
public void paintTrack(Graphics g) {
/* if (MetalLookAndFeel.usingOcean()) {
oceanPaintTrack(g);
return;
}
*/
Color trackColor = !slider.isEnabled() ? MetalLookAndFeel.getControlShadow() :
slider.getForeground();
// boolean leftToRight = MetalUtils.isLeftToRight(slider);
boolean leftToRight = isLeftToRight(slider);
g.translate( trackRect.x, trackRect.y );
int trackLeft = 0;
int trackTop = 0;
int trackRight;
int trackBottom;
// Draw the track
if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
trackBottom = (trackRect.height - 1) - getThumbOverhang();
trackTop = trackBottom - (getTrackWidth() - 1);
trackRight = trackRect.width - 1;
}
else {
if (leftToRight) {
trackLeft = (trackRect.width - getThumbOverhang()) -
getTrackWidth();
trackRight = (trackRect.width - getThumbOverhang()) - 1;
}
else {
trackLeft = getThumbOverhang();
trackRight = getThumbOverhang() + getTrackWidth() - 1;
}
trackBottom = trackRect.height - 1;
}
if ( slider.isEnabled() ) {
g.setColor( MetalLookAndFeel.getControlDarkShadow() );
g.drawRect( trackLeft, trackTop,
(trackRight - trackLeft) - 1, (trackBottom - trackTop) - 1 );
g.setColor( MetalLookAndFeel.getControlHighlight() );
g.drawLine( trackLeft + 1, trackBottom, trackRight, trackBottom );
g.drawLine( trackRight, trackTop + 1, trackRight, trackBottom );
g.setColor( MetalLookAndFeel.getControlShadow() );
g.drawLine( trackLeft + 1, trackTop + 1, trackRight - 2, trackTop + 1 );
g.drawLine( trackLeft + 1, trackTop + 1, trackLeft + 1, trackBottom - 2 );
}
else {
g.setColor( MetalLookAndFeel.getControlShadow() );
g.drawRect( trackLeft, trackTop,
(trackRight - trackLeft) - 1, (trackBottom - trackTop) - 1 );
}
// Draw the fill
if ( filledSlider ) {
int middleOfThumb;
int fillTop;
int fillLeft;
int fillBottom;
int fillRight;
if ( slider.getOrientation() == JSlider.HORIZONTAL ) {
middleOfThumb = thumbRect.x + (thumbRect.width / 2);
middleOfThumb -= trackRect.x; // To compensate for the g.translate()
fillTop = !slider.isEnabled() ? trackTop : trackTop + 1;
fillBottom = !slider.isEnabled() ? trackBottom - 1 : trackBottom - 2;
if ( !drawInverted() ) {
fillLeft = !slider.isEnabled() ? trackLeft : trackLeft + 1;
fillRight = middleOfThumb;
}
else {
fillLeft = middleOfThumb;
fillRight = !slider.isEnabled() ? trackRight - 1 : trackRight - 2;
}
}
else {
middleOfThumb = thumbRect.y + (thumbRect.height / 2);
middleOfThumb -= trackRect.y; // To compensate for the g.translate()
fillLeft = !slider.isEnabled() ? trackLeft : trackLeft + 1;
fillRight = !slider.isEnabled() ? trackRight - 1 : trackRight - 2;
if ( !drawInverted() ) {
fillTop = middleOfThumb;
fillBottom = !slider.isEnabled() ? trackBottom - 1 : trackBottom - 2;
}
else {
fillTop = !slider.isEnabled() ? trackTop : trackTop + 1;
fillBottom = middleOfThumb;
}
}
if ( slider.isEnabled() ) {
g.setColor( slider.getBackground() );
g.drawLine( fillLeft, fillTop, fillRight, fillTop );
g.drawLine( fillLeft, fillTop, fillLeft, fillBottom );
g.setColor( MetalLookAndFeel.getControlShadow() );
g.fillRect( fillLeft + 1, fillTop + 1,
fillRight - fillLeft, fillBottom - fillTop );
}
else {
g.setColor( MetalLookAndFeel.getControlShadow() );
g.fillRect(fillLeft, fillTop, fillRight - fillLeft, fillBottom - fillTop);
}
}
g.translate( -trackRect.x, -trackRect.y );
}
static boolean isLeftToRight( Component c ) {
return c.getComponentOrientation().isLeftToRight();
}
}
ZoomJSlider:
import javax.swing.BoundedRangeModel;
import javax.swing.JSlider;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.metal.MetalSliderUI;
/**
*
* @author Francisco Javier Rojas Garrido <frojasg1@hotmail.com>
*/
public class ZoomJSlider extends JSlider implements ZoomInterface
{
protected double _zoomFactor = 1.0D;
public ZoomJSlider() {
super();
}
public ZoomJSlider(int orientation) {
super(orientation);
}
public ZoomJSlider(int min, int max) {
super(min, max);
}
public ZoomJSlider(int min, int max, int value) {
super(min, max, value);
}
public ZoomJSlider(int orientation, int min, int max, int value)
{
super(orientation, min, max, value);
}
public ZoomJSlider(BoundedRangeModel brm)
{
super( brm );
}
public void switchToZoomUI()
{
ComponentUI compUi = getUI();
ComponentUI newUi = null;
if( ( compUi instanceof MetalSliderUI ) &&
!( compUi instanceof ZoomMetalSliderUI ) )
{
newUi = new ZoomMetalSliderUI();
}
if( newUi != null )
{
setUI(newUi);
( (ZoomInterface) newUi ).setZoomFactor(_zoomFactor);
}
}
@Override
public void setZoomFactor( double zoomFactor )
{
_zoomFactor = zoomFactor;
ComponentUI compUi = getUI();
if( compUi instanceof ZoomInterface )
{
ZoomInterface zi = (ZoomInterface) compUi;
zi.setZoomFactor(zoomFactor);
}
repaint();
}
@Override
public double getZoomFactor()
{
return( _zoomFactor );
}
}
Main class:
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.plaf.metal.MetalLookAndFeel;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author Francisco Javier Rojas Garrido <frojasg1@hotmail.com>
*/
public class Main
{
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
javax.swing.UIManager.setLookAndFeel(MetalLookAndFeel.class.getName());
} catch (ClassNotFoundException ex) {
Logger.getLogger(MetalLookAndFeel.class.getName()).log(Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
Logger.getLogger(MetalLookAndFeel.class.getName()).log(Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
Logger.getLogger(MetalLookAndFeel.class.getName()).log(Level.SEVERE, null, ex);
} catch (UnsupportedLookAndFeelException ex) {
Logger.getLogger(MetalLookAndFeel.class.getName()).log(Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
try
{
new Window().setVisible(true);
}
catch( Throwable th )
{
th.printStackTrace();
}
}
});
}
}
Window class:
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Point;
import javax.swing.JFrame;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
/**
*
* @author Francisco Javier Rojas Garrido <frojasg1@hotmail.com>
*/
public class Window extends JFrame implements ChangeListener
{
protected Dimension _dimen = new Dimension( 250, 30 );
protected ZoomJSlider _jSlider = null;
protected javax.swing.JPanel _jPanel1;
public Window()
{
super( );
initComponents();
setListeners();
}
protected void initComponents()
{
_jPanel1 = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
getContentPane().setLayout(null);
_jPanel1.setLayout(null);
_jSlider = new ZoomJSlider( 50, 200, 100 );
_jPanel1.add( _jSlider );
_jSlider.switchToZoomUI();
_jSlider.setBounds( 20, 30, (int) _dimen.getWidth(), (int) _dimen.getHeight() );
getContentPane().add(_jPanel1);
_jPanel1.setBounds(0, 0, 600, 120);
setSize( 650, 170 );
setLocation( getCenteredLocationForComponent( this ) );
}
protected void setListeners()
{
_jSlider.addChangeListener( this );
}
@Override
public void stateChanged( ChangeEvent ce )
{
double zoomFactor = _jSlider.getValue() / 100.0D;
_jSlider.setZoomFactor( zoomFactor );
Dimension size = ViewFunctions.instance().getNewDimension(_dimen, null, zoomFactor);
_jSlider.setBounds( _jSlider.getX(), _jSlider.getY(),
(int) size.getWidth(), (int) size.getHeight() );
}
public static Point getCenteredLocationForComponent( Component comp )
{
int width = java.awt.Toolkit.getDefaultToolkit().getScreenSize().width;
int height = java.awt.Toolkit.getDefaultToolkit().getScreenSize().height;
Point result = new Point( width/2 - comp.getWidth()/2, height/2 - comp.getHeight()/2 );
return( result );
}
}
Other classes:
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.Raster;
/**
*
* @author Usuario
*/
public class ImageFunctions
{
public static BufferedImage resizeImage( BufferedImage original, int width, int height, Integer switchColorFrom,
Integer switchColorTo, Integer alphaForPixelsDifferentFromColorFrom ) throws IllegalArgumentException
{
int alpha = 0xFF000000;
if( alphaForPixelsDifferentFromColorFrom != null )
alpha = ( (alphaForPixelsDifferentFromColorFrom) & 0xFF ) << 24;
if( ( width < 1 ) || ( height < 1 ) ) throw( new IllegalArgumentException( "Bad size for image. Width: " + width + ". Height: " + height ) );
BufferedImage result = new BufferedImage( width, height, BufferedImage.TYPE_INT_ARGB );
double factorX = ((double) original.getWidth()) / width ;
double factorY = ( (double) original.getHeight() ) / height;
int[] pixels = getRGB( 0, 0, original.getWidth(), original.getHeight(), original );
double transformedY = 0.5d;
for( int tY = 0; tY < height; transformedY += 1, tY++ )
{
int originalOffsetY = (int) ( Math.floor(transformedY*factorY) ) * original.getWidth();
double transformedX = 0.5D;
for( int tX = 0; tX < width; transformedX += 1, tX++ )
{
int originalX = (int) ( Math.floor( transformedX*factorX ) );
int pixelColor = pixels[ originalOffsetY+originalX ];
if( ( switchColorFrom != null ) && ( pixelColor == switchColorFrom ) )
{
if( switchColorTo != null ) pixelColor = switchColorTo;
else pixelColor = pixelColor & 0xFFFFFF;
}
else if( alphaForPixelsDifferentFromColorFrom != null )
{
pixelColor = pixelColor & 0xFFFFFF | alpha;
}
result.setRGB( tX, tY, pixelColor );
}
}
return( result );
}
/**
* Returns an array of integer pixels in the default RGB color model
* (TYPE_INT_ARGB) and default sRGB color space,
* from a portion of the image data. Color conversion takes
* place if the default model does not match the image
* <code>ColorModel</code>. There are only 8-bits of precision for
* each color component in the returned data when
* using this method. With a specified coordinate (x, y) in the
* image, the ARGB pixel can be accessed in this way:
* </p>
*
* <pre>
* pixel = rgbArray[offset + (y-startY)*scansize + (x-startX)]; </pre>
*
* <p>
*
* An <code>ArrayOutOfBoundsException</code> may be thrown
* if the region is not in bounds.
* However, explicit bounds checking is not guaranteed.
*
* @param startX the starting X coordinate
* @param startY the starting Y coordinate
* @param w width of region
* @param h height of region
* @param rgbArray if not <code>null</code>, the rgb pixels are
* written here
* @param offset offset into the <code>rgbArray</code>
* @param scansize scanline stride for the <code>rgbArray</code>
* @return array of RGB pixels.
* @see #setRGB(int, int, int)
* @see #setRGB(int, int, int, int, int[], int, int)
*/
public static int[] getRGB(int startX, int startY, int w, int h,
BufferedImage bi )
{
ColorModel colorModel = bi.getColorModel();
Raster raster = bi.getRaster();
// WritableRaster raster = colorModel.createCompatibleWritableRaster( bi.getWidth(), bi.getHeight() );
int scansize = w;
int offset =0;
int yoff = offset;
int off;
Object data;
int nbands = raster.getNumBands();
int dataType = raster.getDataBuffer().getDataType();
switch (dataType)
{
case DataBuffer.TYPE_BYTE:
data = new byte[nbands];
break;
case DataBuffer.TYPE_USHORT:
data = new short[nbands];
break;
case DataBuffer.TYPE_INT:
data = new int[nbands];
break;
case DataBuffer.TYPE_FLOAT:
data = new float[nbands];
break;
case DataBuffer.TYPE_DOUBLE:
data = new double[nbands];
break;
default:
throw new IllegalArgumentException("Unknown data buffer type: "+
dataType);
}
int[] rgbArray = new int[offset+h*scansize];
for (int y = startY; y < startY+h; y++, yoff+=scansize)
{
off = yoff;
for (int x = startX; x < startX+w; x++)
{
if( (x>=0) && (x<bi.getWidth()) && (y>=0) && (y<bi.getHeight() ) )
{
rgbArray[off++] = colorModel.getRGB(raster.getDataElements( x,
y,
data));
}
else
{
rgbArray[off++] = 0;
}
}
}
return rgbArray;
}
}
public class IntegerFunctions
{
public static int max( int i1, int i2 )
{
return( i1>i2 ? i1 : i2 );
}
public static int min( int i1, int i2 )
{
return( i1<i2 ? i1 : i2 );
}
public static int abs( int ii )
{
return( ii>=0 ? ii : -ii );
}
public static int sgn( int ii )
{
return( ii>0 ? 1 : ( ii<0 ? -1 : 0 ) );
}
}
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Rectangle;
/**
*
* @author Usuario
*/
public class ViewFunctions
{
protected static ViewFunctions _instance;
public static ViewFunctions instance()
{
if( _instance == null )
_instance = new ViewFunctions();
return( _instance );
}
public Dimension getNewDimension( Dimension dim, Insets insets, double zoomFactor )
{
Dimension result = null;
if( dim != null )
{
if( insets == null )
insets = new Insets(0,0,0,0);
int insetsWidth = insets.left + insets.right;
int insetsHeight = insets.top + insets.bottom;
result = new Dimension( (int) ( zoomFactor * ( dim.getWidth() - insetsWidth ) + insetsWidth ),
(int) ( zoomFactor * ( dim.getHeight() - insetsHeight ) + insetsHeight ) );
}
return( result );
}
public Rectangle getNewRectangle( Rectangle rect, Insets insets, double zoomFactor )
{
Rectangle result = null;
if( rect != null )
{
if( insets == null )
insets = new Insets(0,0,0,0);
int insetsWidth = insets.left + insets.right;
int insetsHeight = insets.top + insets.bottom;
result = new Rectangle( (int) ( zoomFactor * ( rect.getX() + insets.left ) - insets.left ),
(int) ( zoomFactor * ( rect.getY() + insets.top ) - insets.top ),
(int) ( zoomFactor * ( rect.getWidth() - insetsWidth ) + insetsWidth ),
(int) ( zoomFactor * ( rect.getHeight() - insetsHeight ) + insetsHeight ) );
}
return( result );
}
public Insets getNewInsets( Insets insets, double zoomFactor )
{
Insets result = null;
if( insets != null )
{
result = new Insets( (int) ( insets.top * zoomFactor ),
(int) ( insets.left * zoomFactor ),
(int) ( insets.bottom * zoomFactor ),
(int) ( insets.right * zoomFactor ) );
}
return( result );
}
public Point getCenter( Rectangle rect )
{
Point result = null;
if( rect != null )
{
result = new Point( (int) ( rect.getX() + rect.getWidth() / 2 ),
(int) ( rect.getY() + rect.getHeight() / 2 ) );
}
return( result );
}
public Rectangle calculateNewBounds( Rectangle originalBounds, Insets insets, Point center, double zoomFactor )
{
Rectangle result = null;
if( originalBounds != null )
{
if( insets == null )
insets = new Insets( 0, 0, 0, 0 );
int newX = (int) originalBounds.getX();
int newY = (int) originalBounds.getY();
if( center != null )
{
newX = (int) ( center.getX() - insets.left + ( originalBounds.getX() - center.getX() + insets.left ) * zoomFactor );
newY = (int) ( center.getY() - insets.top + ( originalBounds.getY() - center.getY() + insets.top ) * zoomFactor );
}
result = new Rectangle( newX,
newY,
(int) ( ( originalBounds.getWidth() - insets.left - insets.right ) * zoomFactor + insets.left + insets.right ),
(int) ( ( originalBounds.getHeight() - insets.top - insets.bottom ) * zoomFactor + insets.top + insets.bottom )
);
}
return( result );
}
}