// A slider is a widget that varies between a minimum and a maximum // value. The user can drag a "thumb" to change the current value. As // the slider is dragged, Motion() is called. When the slider is // released, Release() is called. Override these two methods to give // the slider behavior. //
// This is (strongly) based on a version by // Adam Doppelt. //
// Fetch the software.
// Fetch the entire Acme package.
public class Slider extends Canvas
{
private static final int THUMB_SIZE = 14;
private static final int BUFFER = 2;
private static final int TEXT_HEIGHT = 15;
private static final int TEXT_BUFFER = 3;
private static final int DEFAULT_WIDTH = 100;
private static final int DEFAULT_HEIGHT = 15;
private static final int MIN_WIDTH = 2 * ( THUMB_SIZE + BUFFER + 1 );
private static final int MIN_HEIGHT = 2 * ( BUFFER + 1 );
private static final int DEFAULT_MIN = 1;
private static final int DEFAULT_MAX = 100;
int value, valueMin, valueMax;
int pixel, pixelMin, pixelMax;
Color barColor, thumbColor, lineColor, textColor;
/// Constructor, all default values.
public Slider()
{
setDefaults();
}
/// Constructor, some specified values.
public Slider( int valueMin, int valueMax )
{
setDefaults();
setMinimum( valueMin );
setMaximum( valueMax );
setValue( valueMin );
}
/// Constructor, some specified values.
public Slider( int valueMin, int valueMax, int width )
{
setDefaults();
setMinimum( valueMin );
setMaximum( valueMax );
setValue( valueMin );
setWidth( width );
}
private void setDefaults()
{
valueMin = DEFAULT_MIN;
valueMax = DEFAULT_MAX;
thumbColor = getBackground();
if ( thumbColor == null )
thumbColor = Color.lightGray;
barColor = thumbColor.darker();
textColor = getForeground();
if ( textColor == null )
textColor = Color.black;
lineColor = textColor;
resize( DEFAULT_WIDTH, DEFAULT_HEIGHT + TEXT_HEIGHT );
// setSize( DEFAULT_WIDTH, DEFAULT_HEIGHT + TEXT_HEIGHT );
setValue( valueMin );
}
/// This method is called when the "thumb" of the slider is moved by
// the user. May be overridden to give the slider some behavior.
public void motion()
{
}
/// This method is called when the "thumb" of the slider is released
// after being moved. May be overridden to give the slider some behavior.
public void release()
{
}
/// Sets the maximum value for the slider.
// @param num The new maximum.
public void setMaximum( int num )
{
valueMax = num;
if ( valueMin > valueMax )
valueMin = valueMax;
setValue( value );
}
/// Sets the minimum value for the slider.
// @param num The new minimum.
public void setMinimum( int num )
{
valueMin = num;
if ( valueMax < valueMin )
valueMax = valueMin;
setValue( value );
}
/// Sets the current value for the slider. The thumb will move to
// reflect the new setting.
// @param num The new setting for the slider.
public void setValue( int num )
{
value = num;
if ( value < valueMin )
value = valueMin;
else if ( value > valueMax )
value = valueMax;
if ( value != valueMin )
pixel = (int) ( Math.round(
Math.abs(
(double) ( value - valueMin ) /
(double) ( valueMax - valueMin ) ) *
(double) ( pixelMax - pixelMin ) ) + pixelMin );
else
pixel = pixelMin;
repaint();
}
/// Sets the height of the slider. This is the height of the entire
// slider canvas, including space reserved for displaying the
// current value.
// @param num The new height.
public void setHeight( int num )
{
if ( num < MIN_HEIGHT + TEXT_HEIGHT )
num = MIN_HEIGHT + TEXT_HEIGHT;
resize( size().width, num );
// setSize( getSize().width, num );
repaint();
}
/// Sets the width of the slider. This is the width of the actual
// slider box.
// @param num The new width.
public void setWidth( int num )
{
if ( num < MIN_WIDTH )
num = MIN_WIDTH;
resize( num, size().height );
// setSize( num, getSize().height );
repaint();
}
/// Sets the color for the slider's bar. The "bar" is the rectangle
// that the thumb slides around in.
// @param color The new bar color.
public void setBarColor( Color color )
{
barColor = color;
repaint();
}
/// Sets the color for the slider's thumb. The "thumb" is the box that
// the user can slide back and forth.
// @param color The new thumb color.
public void setThumbColor( Color color )
{
thumbColor = color;
repaint();
}
/// Sets the line color for the slider - the little vertical line
// on the thumb.
// @param color The new line color.
public void setLineColor( Color color )
{
lineColor = color;
repaint();
}
/// Sets the color for the slider`s text.
// @param color The new text color.
public void setTextColor( Color color )
{
textColor = color;
repaint();
}
/// Returns the current value for the slider.
// @return The current value for the slider.
public int getValue()
{
return value;
}
public void paint( Graphics g )
{
int width = size().width;
// int width = getSize().width;
int height = size().height;
// int height = getSize().height;
g.setColor( barColor );
g.fill3DRect(
0, TEXT_HEIGHT, width, height - TEXT_HEIGHT, false );
g.setColor( thumbColor );
g.fill3DRect(
pixel - THUMB_SIZE, TEXT_HEIGHT + BUFFER,
THUMB_SIZE * 2 + 1, height - 2 * BUFFER - TEXT_HEIGHT, true );
g.setColor( lineColor );
g.drawLine(
pixel, TEXT_HEIGHT + BUFFER + 1, pixel, height - 2 * BUFFER );
g.setColor( textColor );
String str = String.valueOf( value );
int strWidth = getFontMetrics( g.getFont() ).stringWidth( str );
g.drawString( str, pixel - strWidth / 2, TEXT_HEIGHT - TEXT_BUFFER );
}
public void setBounds( int x, int y, int width, int height )
{
super.setBounds( x, y, width, height );
pixelMin = THUMB_SIZE + BUFFER;
pixelMax = width - THUMB_SIZE - BUFFER - 1;
if ( value != valueMin )
pixel = (int) ( Math.round(
Math.abs(
(double) ( value - valueMin ) /
(double) ( valueMax - valueMin ) ) *
(double) ( pixelMax - pixelMin ) ) + pixelMin );
else
pixel = pixelMin;
}
public boolean mouseDown( Event e, int x, int y )
{
if ( x >= pixel - THUMB_SIZE && x <= pixel + THUMB_SIZE )
{
if ( x < pixel )
setValue( value - 1 );
else if ( x > pixel )
setValue( value + 1 );
}
else
mouseAction( x );
motion();
return true;
}
public boolean mouseDrag( Event e, int x, int y )
{
mouseAction( x );
motion();
return true;
}
public boolean mouseUp( Event e, int x, int y )
{
release();
return true;
}
private void mouseAction( int x )
{
double percent;
pixel = Math.min( Math.max( x, pixelMin ), pixelMax );
if ( pixel != pixelMin )
percent = ( (double) pixel - pixelMin ) / ( pixelMax - pixelMin );
else
percent = 0;
value =
(int) ( Math.round( percent * (double) ( valueMax - valueMin ) ) ) +
valueMin;
repaint();
}
}