org.meteoinfo.ui.slider.RangeSliderUI Maven / Gradle / Ivy
package org.meteoinfo.ui.slider;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import javax.swing.JComponent;
import javax.swing.JSlider;
import javax.swing.SwingUtilities;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.plaf.basic.BasicSliderUI;
/**
* UI delegate for the RangeSlider component. RangeSliderUI paints two thumbs,
* one for the lower value and one for the upper value.
*/
class RangeSliderUI extends BasicSliderUI {
/** Color of selected range. */
private Color rangeColor = Color.GREEN;
/** Location and size of thumb for upper value. */
private Rectangle upperThumbRect;
/** Indicator that determines whether upper thumb is selected. */
private boolean upperThumbSelected;
/** Indicator that determines whether lower thumb is being dragged. */
private transient boolean lowerDragging;
/** Indicator that determines whether upper thumb is being dragged. */
private transient boolean upperDragging;
/**
* Constructs a RangeSliderUI for the specified slider component.
* @param b RangeSlider
*/
public RangeSliderUI(RangeSlider b) {
super(b);
}
/**
* Installs this UI delegate on the specified component.
*/
@Override
public void installUI(JComponent c) {
upperThumbRect = new Rectangle();
super.installUI(c);
}
/**
* Creates a listener to handle track events in the specified slider.
*/
@Override
protected TrackListener createTrackListener(JSlider slider) {
return new RangeTrackListener();
}
/**
* Creates a listener to handle change events in the specified slider.
*/
@Override
protected ChangeListener createChangeListener(JSlider slider) {
return new ChangeHandler();
}
/**
* Updates the dimensions for both thumbs.
*/
@Override
protected void calculateThumbSize() {
// Call superclass method for lower thumb size.
super.calculateThumbSize();
// Set upper thumb size.
upperThumbRect.setSize(thumbRect.width, thumbRect.height);
}
/**
* Updates the locations for both thumbs.
*/
@Override
protected void calculateThumbLocation() {
// Call superclass method for lower thumb location.
super.calculateThumbLocation();
// Adjust upper value to snap to ticks if necessary.
if (slider.getSnapToTicks()) {
int upperValue = slider.getValue() + slider.getExtent();
int snappedValue = upperValue;
int majorTickSpacing = slider.getMajorTickSpacing();
int minorTickSpacing = slider.getMinorTickSpacing();
int tickSpacing = 0;
if (minorTickSpacing > 0) {
tickSpacing = minorTickSpacing;
} else if (majorTickSpacing > 0) {
tickSpacing = majorTickSpacing;
}
if (tickSpacing != 0) {
// If it's not on a tick, change the value
if ((upperValue - slider.getMinimum()) % tickSpacing != 0) {
float temp = (float)(upperValue - slider.getMinimum()) / (float)tickSpacing;
int whichTick = Math.round(temp);
snappedValue = slider.getMinimum() + (whichTick * tickSpacing);
}
if (snappedValue != upperValue) {
slider.setExtent(snappedValue - slider.getValue());
}
}
}
// Calculate upper thumb location. The thumb is centered over its
// value on the track.
if (slider.getOrientation() == JSlider.HORIZONTAL) {
int upperPosition = xPositionForValue(slider.getValue() + slider.getExtent());
upperThumbRect.x = upperPosition - (upperThumbRect.width / 2);
upperThumbRect.y = trackRect.y;
} else {
int upperPosition = yPositionForValue(slider.getValue() + slider.getExtent());
upperThumbRect.x = trackRect.x;
upperThumbRect.y = upperPosition - (upperThumbRect.height / 2);
}
}
/**
* Returns the size of a thumb.
*/
@Override
protected Dimension getThumbSize() {
return new Dimension(12, 12);
}
/**
* Paints the slider. The selected thumb is always painted on top of the
* other thumb.
*/
@Override
public void paint(Graphics g, JComponent c) {
super.paint(g, c);
Rectangle clipRect = g.getClipBounds();
if (upperThumbSelected) {
// Paint lower thumb first, then upper thumb.
if (clipRect.intersects(thumbRect)) {
paintLowerThumb(g);
}
if (clipRect.intersects(upperThumbRect)) {
paintUpperThumb(g);
}
} else {
// Paint upper thumb first, then lower thumb.
if (clipRect.intersects(upperThumbRect)) {
paintUpperThumb(g);
}
if (clipRect.intersects(thumbRect)) {
paintLowerThumb(g);
}
}
}
/**
* Paints the track.
*/
@Override
public void paintTrack(Graphics g) {
// Draw track.
super.paintTrack(g);
Rectangle trackBounds = trackRect;
if (slider.getOrientation() == JSlider.HORIZONTAL) {
// Determine position of selected range by moving from the middle
// of one thumb to the other.
int lowerX = thumbRect.x + (thumbRect.width / 2);
int upperX = upperThumbRect.x + (upperThumbRect.width / 2);
// Determine track position.
int cy = (trackBounds.height / 2) - 2;
// Save color and shift position.
Color oldColor = g.getColor();
g.translate(trackBounds.x, trackBounds.y + cy);
// Draw selected range.
g.setColor(rangeColor);
for (int y = 0; y <= 3; y++) {
g.drawLine(lowerX - trackBounds.x, y, upperX - trackBounds.x, y);
}
// Restore position and color.
g.translate(-trackBounds.x, -(trackBounds.y + cy));
g.setColor(oldColor);
} else {
// Determine position of selected range by moving from the middle
// of one thumb to the other.
int lowerY = thumbRect.x + (thumbRect.width / 2);
int upperY = upperThumbRect.x + (upperThumbRect.width / 2);
// Determine track position.
int cx = (trackBounds.width / 2) - 2;
// Save color and shift position.
Color oldColor = g.getColor();
g.translate(trackBounds.x + cx, trackBounds.y);
// Draw selected range.
g.setColor(rangeColor);
for (int x = 0; x <= 3; x++) {
g.drawLine(x, lowerY - trackBounds.y, x, upperY - trackBounds.y);
}
// Restore position and color.
g.translate(-(trackBounds.x + cx), -trackBounds.y);
g.setColor(oldColor);
}
}
/**
* Overrides superclass method to do nothing. Thumb painting is handled
* within the paint() method.
*/
@Override
public void paintThumb(Graphics g) {
// Do nothing.
}
/**
* Paints the thumb for the lower value using the specified graphics object.
*/
private void paintLowerThumb(Graphics g) {
Rectangle knobBounds = thumbRect;
int w = knobBounds.width;
int h = knobBounds.height;
// Create graphics copy.
Graphics2D g2d = (Graphics2D) g.create();
// Create default thumb shape.
Shape thumbShape = createThumbShape(w - 1, h - 1);
// Draw thumb.
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2d.translate(knobBounds.x, knobBounds.y);
g2d.setColor(Color.CYAN);
g2d.fill(thumbShape);
g2d.setColor(Color.BLUE);
g2d.draw(thumbShape);
// Dispose graphics.
g2d.dispose();
}
/**
* Paints the thumb for the upper value using the specified graphics object.
*/
private void paintUpperThumb(Graphics g) {
Rectangle knobBounds = upperThumbRect;
int w = knobBounds.width;
int h = knobBounds.height;
// Create graphics copy.
Graphics2D g2d = (Graphics2D) g.create();
// Create default thumb shape.
Shape thumbShape = createThumbShape(w - 1, h - 1);
// Draw thumb.
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2d.translate(knobBounds.x, knobBounds.y);
g2d.setColor(Color.PINK);
g2d.fill(thumbShape);
g2d.setColor(Color.RED);
g2d.draw(thumbShape);
// Dispose graphics.
g2d.dispose();
}
/**
* Returns a Shape representing a thumb.
*/
private Shape createThumbShape(int width, int height) {
// Use circular shape.
Ellipse2D shape = new Ellipse2D.Double(0, 0, width, height);
return shape;
}
/**
* Sets the location of the upper thumb, and repaints the slider. This is
* called when the upper thumb is dragged to repaint the slider. The
* setThumbLocation() method performs the same task for the
* lower thumb.
*/
private void setUpperThumbLocation(int x, int y) {
Rectangle upperUnionRect = new Rectangle();
upperUnionRect.setBounds(upperThumbRect);
upperThumbRect.setLocation(x, y);
SwingUtilities.computeUnion(upperThumbRect.x, upperThumbRect.y, upperThumbRect.width, upperThumbRect.height, upperUnionRect);
slider.repaint(upperUnionRect.x, upperUnionRect.y, upperUnionRect.width, upperUnionRect.height);
}
/**
* Moves the selected thumb in the specified direction by a block increment.
* This method is called when the user presses the Page Up or Down keys.
*/
public void scrollByBlock(int direction) {
synchronized (slider) {
int blockIncrement = (slider.getMaximum() - slider.getMinimum()) / 10;
if (blockIncrement <= 0 && slider.getMaximum() > slider.getMinimum()) {
blockIncrement = 1;
}
int delta = blockIncrement * ((direction > 0) ? POSITIVE_SCROLL : NEGATIVE_SCROLL);
if (upperThumbSelected) {
int oldValue = ((RangeSlider) slider).getUpperValue();
((RangeSlider) slider).setUpperValue(oldValue + delta);
} else {
int oldValue = slider.getValue();
slider.setValue(oldValue + delta);
}
}
}
/**
* Moves the selected thumb in the specified direction by a unit increment.
* This method is called when the user presses one of the arrow keys.
*/
public void scrollByUnit(int direction) {
synchronized (slider) {
int delta = 1 * ((direction > 0) ? POSITIVE_SCROLL : NEGATIVE_SCROLL);
if (upperThumbSelected) {
int oldValue = ((RangeSlider) slider).getUpperValue();
((RangeSlider) slider).setUpperValue(oldValue + delta);
} else {
int oldValue = slider.getValue();
slider.setValue(oldValue + delta);
}
}
}
/**
* Listener to handle model change events. This calculates the thumb
* locations and repaints the slider if the value change is not caused by
* dragging a thumb.
*/
public class ChangeHandler implements ChangeListener {
public void stateChanged(ChangeEvent arg0) {
if (!lowerDragging && !upperDragging) {
calculateThumbLocation();
slider.repaint();
}
}
}
/**
* Listener to handle mouse movements in the slider track.
*/
public class RangeTrackListener extends TrackListener {
@Override
public void mousePressed(MouseEvent e) {
if (!slider.isEnabled()) {
return;
}
currentMouseX = e.getX();
currentMouseY = e.getY();
if (slider.isRequestFocusEnabled()) {
slider.requestFocus();
}
// Determine which thumb is pressed. If the upper thumb is
// selected (last one dragged), then check its position first;
// otherwise check the position of the lower thumb first.
boolean lowerPressed = false;
boolean upperPressed = false;
if (upperThumbSelected || slider.getMinimum() == slider.getValue()) {
if (upperThumbRect.contains(currentMouseX, currentMouseY)) {
upperPressed = true;
} else if (thumbRect.contains(currentMouseX, currentMouseY)) {
lowerPressed = true;
}
} else {
if (thumbRect.contains(currentMouseX, currentMouseY)) {
lowerPressed = true;
} else if (upperThumbRect.contains(currentMouseX, currentMouseY)) {
upperPressed = true;
}
}
// Handle lower thumb pressed.
if (lowerPressed) {
switch (slider.getOrientation()) {
case JSlider.VERTICAL:
offset = currentMouseY - thumbRect.y;
break;
case JSlider.HORIZONTAL:
offset = currentMouseX - thumbRect.x;
break;
}
upperThumbSelected = false;
lowerDragging = true;
return;
}
lowerDragging = false;
// Handle upper thumb pressed.
if (upperPressed) {
switch (slider.getOrientation()) {
case JSlider.VERTICAL:
offset = currentMouseY - upperThumbRect.y;
break;
case JSlider.HORIZONTAL:
offset = currentMouseX - upperThumbRect.x;
break;
}
upperThumbSelected = true;
upperDragging = true;
return;
}
upperDragging = false;
}
@Override
public void mouseReleased(MouseEvent e) {
lowerDragging = false;
upperDragging = false;
slider.setValueIsAdjusting(false);
super.mouseReleased(e);
}
@Override
public void mouseDragged(MouseEvent e) {
if (!slider.isEnabled()) {
return;
}
currentMouseX = e.getX();
currentMouseY = e.getY();
if (lowerDragging) {
slider.setValueIsAdjusting(true);
moveLowerThumb();
} else if (upperDragging) {
slider.setValueIsAdjusting(true);
moveUpperThumb();
}
}
@Override
public boolean shouldScroll(int direction) {
return false;
}
/**
* Moves the location of the lower thumb, and sets its corresponding
* value in the slider.
*/
private void moveLowerThumb() {
int thumbMiddle = 0;
switch (slider.getOrientation()) {
case JSlider.VERTICAL:
int halfThumbHeight = thumbRect.height / 2;
int thumbTop = currentMouseY - offset;
int trackTop = trackRect.y;
int trackBottom = trackRect.y + (trackRect.height - 1);
int vMax = yPositionForValue(slider.getValue() + slider.getExtent());
// Apply bounds to thumb position.
if (drawInverted()) {
trackBottom = vMax;
} else {
trackTop = vMax;
}
thumbTop = Math.max(thumbTop, trackTop - halfThumbHeight);
thumbTop = Math.min(thumbTop, trackBottom - halfThumbHeight);
setThumbLocation(thumbRect.x, thumbTop);
// Update slider value.
thumbMiddle = thumbTop + halfThumbHeight;
slider.setValue(valueForYPosition(thumbMiddle));
break;
case JSlider.HORIZONTAL:
int halfThumbWidth = thumbRect.width / 2;
int thumbLeft = currentMouseX - offset;
int trackLeft = trackRect.x;
int trackRight = trackRect.x + (trackRect.width - 1);
int hMax = xPositionForValue(slider.getValue() + slider.getExtent());
// Apply bounds to thumb position.
if (drawInverted()) {
trackLeft = hMax;
} else {
trackRight = hMax;
}
thumbLeft = Math.max(thumbLeft, trackLeft - halfThumbWidth);
thumbLeft = Math.min(thumbLeft, trackRight - halfThumbWidth);
setThumbLocation(thumbLeft, thumbRect.y);
// Update slider value.
thumbMiddle = thumbLeft + halfThumbWidth;
slider.setValue(valueForXPosition(thumbMiddle));
break;
default:
return;
}
}
/**
* Moves the location of the upper thumb, and sets its corresponding
* value in the slider.
*/
private void moveUpperThumb() {
int thumbMiddle = 0;
switch (slider.getOrientation()) {
case JSlider.VERTICAL:
int halfThumbHeight = thumbRect.height / 2;
int thumbTop = currentMouseY - offset;
int trackTop = trackRect.y;
int trackBottom = trackRect.y + (trackRect.height - 1);
int vMin = yPositionForValue(slider.getValue());
// Apply bounds to thumb position.
if (drawInverted()) {
trackTop = vMin;
} else {
trackBottom = vMin;
}
thumbTop = Math.max(thumbTop, trackTop - halfThumbHeight);
thumbTop = Math.min(thumbTop, trackBottom - halfThumbHeight);
setUpperThumbLocation(thumbRect.x, thumbTop);
// Update slider extent.
thumbMiddle = thumbTop + halfThumbHeight;
slider.setExtent(valueForYPosition(thumbMiddle) - slider.getValue());
break;
case JSlider.HORIZONTAL:
int halfThumbWidth = thumbRect.width / 2;
int thumbLeft = currentMouseX - offset;
int trackLeft = trackRect.x;
int trackRight = trackRect.x + (trackRect.width - 1);
int hMin = xPositionForValue(slider.getValue());
// Apply bounds to thumb position.
if (drawInverted()) {
trackRight = hMin;
} else {
trackLeft = hMin;
}
thumbLeft = Math.max(thumbLeft, trackLeft - halfThumbWidth);
thumbLeft = Math.min(thumbLeft, trackRight - halfThumbWidth);
setUpperThumbLocation(thumbLeft, thumbRect.y);
// Update slider extent.
thumbMiddle = thumbLeft + halfThumbWidth;
slider.setExtent(valueForXPosition(thumbMiddle) - slider.getValue());
break;
default:
return;
}
}
}
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