Add floating point number support to scroll bars in number widget

Author: imagejan

src/main/java/org/scijava/ui/swing/widget/SwingNumberWidget.java

@@ -30,7 +30,6 @@
 
 package org.scijava.ui.swing.widget;
 
-import java.awt.Adjustable;
 import java.awt.Component;
 import java.awt.Dimension;
 import java.awt.event.AdjustmentEvent;
@@ -84,7 +83,7 @@ public class SwingNumberWidget extends SwingInputWidget<Number> implements
 	@Parameter
 	private LogService log;
 
-	private JScrollBar scrollBar;
+	private CalibratedScrollBar scrollBar;
 	private CalibratedSlider slider;
 	private JSpinner spinner;
 
@@ -121,6 +120,9 @@ else if (model.isStyle(NumberWidget.SLIDER_STYLE)) {
 		final SpinnerNumberModel spinnerModel =
 			new SpinnerNumberModelFactory().createModel(value, min, max, stepSize);
 		spinner = new JSpinner(spinnerModel);
+		Dimension spinnerSize = spinner.getSize();
+		spinnerSize.width = 50;
+		spinner.setPreferredSize(spinnerSize);
 		fixSpinner(type);
 		setToolTip(spinner);
 		getComponent().add(spinner);
@@ -143,7 +145,7 @@ public boolean supports(final WidgetModel model) {
 	@Override
 	public void adjustmentValueChanged(final AdjustmentEvent e) {
 		// sync spinner with scroll bar value
-		final int value = scrollBar.getValue();
+		final Number value = scrollBar.getCalibratedValue();
 		spinner.setValue(value);
 	}
 
@@ -168,9 +170,9 @@ else if (source == spinner) {
 
 	@Override
 	public void mouseWheelMoved(final MouseWheelEvent e) {
-		int value = getValue().intValue() + e.getWheelRotation(); // TODO convert from wheel rotations to steps on the slider
-		value = Math.min(value, this.get().getMax().intValue());
-		value = Math.max(value, this.get().getMin().intValue());
+		Number value = getValue().doubleValue() + e.getWheelRotation() * get().getStepSize().doubleValue();
+		value = Math.min(value.doubleValue(), this.get().getMax().doubleValue());
+		value = Math.max(value.doubleValue(), this.get().getMin().doubleValue());
 		spinner.setValue(value);
 		syncSliders();
 	}
@@ -184,14 +186,17 @@ private void addScrollBar(final Number min, final Number max,
 			log.warn("Invalid min/max/step; cannot render scroll bar");
 			return;
 		}
-		int mn = min.intValue();
-		if (mn == Integer.MIN_VALUE) mn = Integer.MIN_VALUE + 1;
-		int mx = max.intValue();
-		if (mx < Integer.MAX_VALUE) mx++;
-		final int st = step.intValue();
-
-		scrollBar = new JScrollBar(Adjustable.HORIZONTAL, mn, 1, mn, mx);
-		scrollBar.setUnitIncrement(st);
+		
+		// TODO Integer cases can possibly be handled in a simpler way
+		int sMin = 0;
+		int sMax = (int) ((max.doubleValue() - min.doubleValue()) / step.doubleValue());
+		long range = sMax - sMin;
+		if (range > Integer.MAX_VALUE) {
+			log.warn("Scrollbar span too large; max - min < 2^31 required.");
+			return;
+		}
+
+		scrollBar = new CalibratedScrollBar(min, max, step);
 		setToolTip(scrollBar);
 		getComponent().add(scrollBar);
 		scrollBar.addAdjustmentListener(this);
@@ -205,7 +210,8 @@ private void addSlider(final Number min, final Number max,
 			log.warn("Invalid min/max/step; cannot render slider");
 			return;
 		}
-		// TODO Integer cases can be handled in a simpler way
+
+		// TODO Integer cases can possibly be handled in a simpler way
 		int sMin = 0;
 		int sMax = (int) ((max.doubleValue() - min.doubleValue()) / step.doubleValue());
 		long range = sMax - sMin;
@@ -214,7 +220,6 @@ private void addSlider(final Number min, final Number max,
 			return;
 		}
 
-		// slider = new JSlider(sMin, sMax, sMin);
 		slider = new CalibratedSlider(min, max, step);
 
 		setToolTip(slider);
@@ -307,7 +312,7 @@ public void run() {
 	private void syncSliders() {
 		if (slider != null) {
 			// clamp value within slider bounds
-			Number value = getValue().intValue();
+			Number value = getValue();
 			if (value.doubleValue() < slider.getCalibratedMinimum().doubleValue()) value = slider.getCalibratedMinimum();
 			else if (value.doubleValue() > slider.getCalibratedMaximum().doubleValue()) value = slider.getCalibratedMaximum();
 			slider.removeChangeListener(this);
@@ -316,11 +321,11 @@ private void syncSliders() {
 		}
 		if (scrollBar != null) {
 			// clamp value within scroll bar bounds
-			int value = getValue().intValue();
-			if (value < scrollBar.getMinimum()) value = scrollBar.getMinimum();
-			else if (value > scrollBar.getMaximum()) value = scrollBar.getMaximum();
+			Number value = getValue();
+			if (value.doubleValue() < scrollBar.getCalibratedMinimum().doubleValue()) value = scrollBar.getCalibratedMinimum();
+			else if (value.doubleValue() > scrollBar.getCalibratedMaximum().doubleValue()) value = scrollBar.getCalibratedMaximum();
 			scrollBar.removeAdjustmentListener(this);
-			scrollBar.setValue(getValue().intValue());
+			scrollBar.setCalibratedValue(value);
 			scrollBar.addAdjustmentListener(this);
 		}
 	}
@@ -409,7 +414,7 @@ private Number getCalibratedMaximum() {
 		}
 
 		private int fromCalibrated(Number n) {
-			return (int) ((n.doubleValue() - min.doubleValue()) / stepSize.doubleValue());
+			return (int) Math.round((n.doubleValue() - min.doubleValue()) / stepSize.doubleValue());
 		}
 
 		private Number toCalibrated(int n) {
@@ -421,4 +426,55 @@ private JLabel makeLabel(Number n, int scale) {
 		}
 
 	}
+
+	private class CalibratedScrollBar extends JScrollBar {
+		
+		private Number min;
+		private Number max;
+		private Number stepSize;
+		
+		private CalibratedScrollBar(final Number min, final Number max, final Number stepSize) {
+			// set extent to 1 to make sure the scroll bar is visible
+			super(HORIZONTAL, 0, 1, 0, 1);
+
+			this.min = min;
+			this.max = max;
+			this.stepSize = stepSize;
+
+			int sMin = 0;
+			int sMax = (int) ((max.doubleValue() - min.doubleValue()) / stepSize.doubleValue()) + 1;
+
+			// Adjust max to be an integer multiple of stepSize
+			this.max = min.doubleValue() + (sMax-sMin) * stepSize.doubleValue();
+
+			setMinimum(sMin);
+			setMaximum(sMax);
+			setValue(sMin);
+		}
+		
+		private void setCalibratedValue(Number value) {
+			setValue(fromCalibrated(value));
+		}
+
+		private Number getCalibratedValue() {
+			return toCalibrated(getValue());
+		}
+
+		private Number getCalibratedMinimum() {
+			return min;
+		}
+
+		private Number getCalibratedMaximum() {
+			return max;
+		}
+		
+		private int fromCalibrated(Number n) {
+			return (int) Math.round((n.doubleValue() - min.doubleValue()) / stepSize.doubleValue());
+		}
+		
+		private Number toCalibrated(int n) {
+			return n * stepSize.doubleValue() + min.doubleValue();
+		}
+		
+	}
 }