Improve input validation and visual feedback

Author: ctrueden

pom.xml

@@ -112,6 +112,8 @@
 
 		<jdatepicker.version>1.3.2</jdatepicker.version>
 		<object-inspector.version>0.1</object-inspector.version>
+
+		<scijava-common.version>2.100.0</scijava-common.version>
 	</properties>
 
 	<repositories>

src/main/java/org/scijava/ui/swing/SwingDialog.java

@@ -37,10 +37,12 @@
 import java.awt.event.WindowAdapter;
 import java.awt.event.WindowEvent;
 
+import javax.swing.JButton;
 import javax.swing.JDialog;
 import javax.swing.JOptionPane;
 import javax.swing.JPanel;
 import javax.swing.JScrollPane;
+import javax.swing.UIManager;
 import javax.swing.WindowConstants;
 import javax.swing.border.Border;
 import javax.swing.border.EmptyBorder;
@@ -292,6 +294,17 @@ public boolean isVisible() {
 		return optionPane.isVisible();
 	}
 
+	/**
+	 * Gets the OK button of this dialog.
+	 *
+	 * @return the OK button, or {@code null} if not found (e.g., because the
+	 *         dialog does not have an OK button).
+	 */
+	public JButton getOkButton() {
+		final String okText = UIManager.getString("OptionPane.okButtonText");
+		return findButton(buttons, okText);
+	}
+
 	// -- Helper methods --
 
 	private void rebuildPane(final boolean scrollBars) {
@@ -339,6 +352,20 @@ private void rebuildPane(final boolean scrollBars) {
 		}
 	}
 
+	/** Recursively searches a component tree for a {@link JButton} by label. */
+	private JButton findButton(final Component c, final String text) {
+		if (c instanceof JButton && text.equals(((JButton) c).getText())) {
+			return (JButton) c;
+		}
+		if (c instanceof Container) {
+			for (final Component child : ((Container) c).getComponents()) {
+				final JButton found = findButton(child, text);
+				if (found != null) return found;
+			}
+		}
+		return null;
+	}
+
 	/**
 	 * Makes the given component grab the keyboard focus whenever the window gains
 	 * the focus.

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

@@ -29,9 +29,15 @@
 
 package org.scijava.ui.swing.widget;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import javax.swing.JOptionPane;
 import javax.swing.JPanel;
 
+import org.scijava.module.ModuleCanceledException;
+import org.scijava.module.ModuleException;
+import org.scijava.module.ModuleItem;
 import org.scijava.module.Module;
 import org.scijava.module.process.PreprocessorPlugin;
 import org.scijava.plugin.Plugin;
@@ -40,6 +46,7 @@
 import org.scijava.ui.swing.SwingUI;
 import org.scijava.widget.InputHarvester;
 import org.scijava.widget.InputPanel;
+import org.scijava.widget.InputWidget;
 
 /**
  * SwingInputHarvester is an {@link InputHarvester} that collects input
@@ -60,6 +67,53 @@ public SwingInputPanel createInputPanel() {
 		return new SwingInputPanel();
 	}
 
+	@Override
+	public void harvest(final Module module) throws ModuleException {
+		final InputPanel<JPanel, JPanel> inputPanel = createInputPanel();
+		buildPanel(inputPanel, module);
+		if (!inputPanel.hasWidgets()) return;
+
+		// Validate all inputs now so the dialog opens with accurate styling and
+		// the OK button already disabled for any initially invalid values.
+		for (final ModuleItem<?> item : module.getInfo().inputs()) {
+			final InputWidget<?, ?> w = inputPanel.getWidget(item.getName());
+			if (w != null) w.get().updateValidation();
+		}
+		inputPanel.refresh();
+
+		while (true) {
+			// Show the dialog; bail out immediately if canceled.
+			if (!harvestInputs(inputPanel, module)) throw new ModuleCanceledException();
+
+			// Validate all unresolved inputs and collect any error messages.
+			final List<String> errors = new ArrayList<>();
+			for (final ModuleItem<?> item : module.getInfo().inputs()) {
+				if (module.isInputResolved(item.getName())) continue;
+				final String message = item.validateMessage(module);
+				if (message != null && !message.isEmpty()) {
+					// Use the same label logic as DefaultWidgetModel.getWidgetLabel().
+					String label = item.getLabel();
+					if (label == null || label.isEmpty()) {
+						final String name = item.getName();
+						label = name.substring(0, 1).toUpperCase() + name.substring(1);
+					}
+					errors.add(label + ": " + message);
+				}
+			}
+
+			if (errors.isEmpty()) break; // all inputs valid; proceed
+
+			// Show a modal error dialog, then re-open the harvester dialog.
+			JOptionPane.showMessageDialog(
+				null,
+				String.join("\n", errors),
+				"Invalid Input",
+				JOptionPane.ERROR_MESSAGE);
+		}
+
+		processResults(inputPanel, module);
+	}
+
 	@Override
 	public boolean harvestInputs(final InputPanel<JPanel, JPanel> inputPanel,
 		final Module module)
@@ -83,8 +137,21 @@ public boolean harvestInputs(final InputPanel<JPanel, JPanel> inputPanel,
 			new SwingDialog(pane, optionType, messageType, doScrollBars);
 		dialog.setTitle(title);
 		dialog.setModal(modal);
+
+		// Wire the OK button to the panel so validation can enable/disable it.
+		if (inputPanel instanceof SwingInputPanel) {
+			final SwingInputPanel swingPanel = (SwingInputPanel) inputPanel;
+			swingPanel.setOkButton(dialog.getOkButton());
+			swingPanel.updateOkButton();
+		}
+
 		final int rval = dialog.show();
 
+		// Detach the OK button once the dialog closes.
+		if (inputPanel instanceof SwingInputPanel) {
+			((SwingInputPanel) inputPanel).setOkButton(null);
+		}
+
 		// verify return value of dialog
 		return rval == JOptionPane.OK_OPTION;
 	}

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

@@ -29,6 +29,7 @@
 
 package org.scijava.ui.swing.widget;
 
+import javax.swing.JButton;
 import javax.swing.JLabel;
 import javax.swing.JPanel;
 
@@ -48,6 +49,32 @@ public class SwingInputPanel extends AbstractInputPanel<JPanel, JPanel> {
 
 	private JPanel uiComponent;
 
+	/** OK button to enable/disable based on overall validation state, or null. */
+	private JButton okButton;
+
+	// -- SwingInputPanel methods --
+
+	/**
+	 * Sets the OK button that should be enabled or disabled to reflect whether
+	 * all widget values are currently valid. Pass {@code null} to detach.
+	 */
+	void setOkButton(final JButton okButton) {
+		this.okButton = okButton;
+	}
+
+	/**
+	 * Enables the OK button if all widgets are valid, disables it otherwise.
+	 * Does nothing if no OK button has been set via {@link #setOkButton}.
+	 */
+	void updateOkButton() {
+		if (okButton == null) return;
+		final boolean allValid = widgets.values().stream().allMatch(w -> {
+			final String msg = w.get().getValidationMessage();
+			return msg == null || msg.isEmpty();
+		});
+		okButton.setEnabled(allValid);
+	}
+
 	// -- InputPanel methods --
 
 	@Override
@@ -71,6 +98,12 @@ public void addWidget(final InputWidget<?, JPanel> widget) {
 		}
 	}
 
+	@Override
+	public void refresh() {
+		super.refresh(); // refreshWidget() on each widget, which applies validation styling
+		updateOkButton();
+	}
+
 	@Override
 	public Class<JPanel> getWidgetComponentType() {
 		return JPanel.class;

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

@@ -29,8 +29,15 @@
 
 package org.scijava.ui.swing.widget;
 
-import javax.swing.JComponent;
-import javax.swing.JPanel;
+import java.awt.Color;
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import javax.swing.*;
+import javax.swing.border.BevelBorder;
+import javax.swing.border.Border;
 
 import net.miginfocom.swing.MigLayout;
 
@@ -49,6 +56,7 @@ public abstract class SwingInputWidget<T> extends
 {
 
 	private JPanel uiComponent;
+	private Set<JComponent> tooltipped = new HashSet<>();
 
 	// -- WrapperPlugin methods --
 
@@ -61,6 +69,14 @@ public void set(final WidgetModel model) {
 		uiComponent.setLayout(layout);
 	}
 
+	// -- InputWidget methods --
+
+	@Override
+	public void refreshWidget() {
+		super.refreshWidget();
+		refreshValidation();
+	}
+
 	// -- UIComponent methods --
 
 	@Override
@@ -84,9 +100,25 @@ protected UserInterface ui() {
 
 	/** Assigns the model's description as the given component's tool tip. */
 	protected void setToolTip(final JComponent c) {
-		final String desc = get().getItem().getDescription();
-		if (desc == null || desc.isEmpty()) return;
-		c.setToolTipText(desc);
+		tooltipped.add(c);
+	}
+
+	/**
+	 * Updates the widget's border and tooltip to reflect the current validation
+	 * state. A red border and tooltip showing the error message are applied when
+	 * the model's validation message is non-null; both are cleared when valid.
+	 * <p>
+	 * Must be called on the Swing EDT.
+	 * </p>
+	 */
+	protected void refreshValidation() {
+		final String message = get().getValidationMessage();
+		final boolean valid = message == null || message.isEmpty();
+		final JPanel p = getComponent();
+		final Color borderColor = valid ? p.getBackground() : Color.RED;
+		final String tip = valid ? get().getItem().getDescription() : message;
+		p.setBorder(BorderFactory.createLineBorder(borderColor, 1));
+		tooltipped.forEach(c -> c.setToolTipText(tip));
 	}
 
 }