ecommons.waltable/org.eclipse.statet.ecommons.waltable.core/src/org/eclipse/statet/ecommons/waltable/edit/config/DialogErrorHandling.java

/*=============================================================================#
 # Copyright (c) 2012, 2021 Original NatTable authors and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0
 # 
 # Contributors:
 #     Original NatTable authors and others - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ecommons.waltable.edit.config;

import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

import org.eclipse.statet.ecommons.waltable.Messages;
import org.eclipse.statet.ecommons.waltable.data.convert.ConversionFailedException;
import org.eclipse.statet.ecommons.waltable.data.validate.ValidationFailedException;
import org.eclipse.statet.ecommons.waltable.edit.editor.AbstractEditErrorHandler;
import org.eclipse.statet.ecommons.waltable.edit.editor.ICellEditor;
import org.eclipse.statet.ecommons.waltable.edit.editor.IEditErrorHandler;


/**
 * Strategy class for conversion/validation failures.
 * If the entered value is not valid, a warning dialog with the corresponding error message
 * will show up. The warning dialog gives the opportunity to discard the invalid input or
 * change it, which will cause the editor to stay open. 
 * Only handles errors on commit.
 */
public class DialogErrorHandling extends AbstractEditErrorHandler {

	/**
	 * The {@link ICellEditor} for which this {@link DialogErrorHandling} is activated.
	 * Needed so it is possible to operate on it dependent on the users choice.
	 */
	protected ICellEditor editor;
	/**
	 * Flag to configure if this dialog allows to commit invalid data.
	 * This is necessary to implement cross validation in NatTable by using dialogs to
	 * tell the user what is wrong.
	 * By default this value is set to <code>false</code> as cross validation is not
	 * the default validation use case.
	 */
	protected boolean allowCommit= false;
	/**
	 * The shell title that will be used if there is no conversion or validation shell title configured.
	 */
	private String failureShellTitle= Messages.getString("DialogErrorHandlingStrategy.failureTitle"); //$NON-NLS-1$
	/**
	 * The shell title that will be used in case this {@link DialogErrorHandling} is called to handle
	 * a {@link ConversionFailedException}.
	 */
	private String conversionFailureShellTitle= Messages.getString("DialogErrorHandlingStrategy.conversionFailureTitle"); //$NON-NLS-1$
	/**
	 * The shell title that will be used in case this {@link DialogErrorHandling} is called to handle
	 * a {@link ValidationFailedException}.
	 */
	private String validationFailureShellTitle= Messages.getString("DialogErrorHandlingStrategy.validationFailureTitle"); //$NON-NLS-1$
	/**
	 * The text on the button for changing the entered value.
	 */
	private String changeButtonLabel= Messages.getString("DialogErrorHandlingStrategy.warningDialog.changeButton"); //$NON-NLS-1$
	/**
	 * The text on the button to discard the entered value.
	 */
	private String discardButtonLabel= Messages.getString("DialogErrorHandlingStrategy.warningDialog.discardButton");  //$NON-NLS-1$
	/**
	 * The text on the button to commit the entered invalid value. Needed to support cross validation.
	 */
	private final String commitButtonLabel= Messages.getString("DialogErrorHandlingStrategy.warningDialog.commitButton");  //$NON-NLS-1$

	/**
	 * Create a new {@link DialogErrorHandling} with no underlying {@link IEditErrorHandler}
	 * that does not support cross validation.
	 */
	public DialogErrorHandling() {
		this(null, false);
	}
	
	/**
	 * Create a new {@link DialogErrorHandling} with no underlying {@link IEditErrorHandler}
	 * that gives the opportunity to configure the error handling for cross validation.
	 * @param allowCommit Flag to configure if this dialog allows to commit invalid data.
	 * 			If this parameter is set to <code>true</code>, an additional button for committing
	 * 			the invalid data will be provided within the dialog.
	 */
	public DialogErrorHandling(final boolean allowCommit) {
		this(null, allowCommit);
		
	}
	
	/**
	 * Create a new {@link DialogErrorHandling} using the given {@link IEditErrorHandler} as
	 * the underlying to allow chaining of error handling. Using this constructor there is
	 * no cross validation support.
	 * @param underlyingErrorHandler The underlying {@link IEditErrorHandler}
	 */
	public DialogErrorHandling(final IEditErrorHandler underlyingErrorHandler) {
		this(underlyingErrorHandler, false);
	}
	
	/**
	 * Create a new {@link DialogErrorHandling} using the given {@link IEditErrorHandler} as
	 * the underlying to allow chaining of error handling.
	 * @param underlyingErrorHandler The underlying {@link IEditErrorHandler}
	 * @param allowCommit Flag to configure if this dialog allows to commit invalid data.
	 * 			If this parameter is set to <code>true</code>, an additional button for committing
	 * 			the invalid data will be provided within the dialog.
	 */
	public DialogErrorHandling(final IEditErrorHandler underlyingErrorHandler, final boolean allowCommit) {
		super(underlyingErrorHandler);
		this.allowCommit= allowCommit;
	}
	
	/**
	 * {@inheritDoc}
	 * After the error is handled by its underlying {@link IEditErrorHandler},
	 * a dialog will be opened showing the error message to the user, giving the
	 * opportunity to decide if the entered value should be discarded or if the
	 * editor should stay open so the value can be modified.
	 */
	@Override
	public void displayError(final ICellEditor cellEditor, final Exception e) {
		super.displayError(cellEditor, e);
		this.editor= cellEditor;
		
		String shellTitle= this.failureShellTitle;
		if (e instanceof ConversionFailedException && this.conversionFailureShellTitle != null) {
			shellTitle= this.conversionFailureShellTitle;
		} else if (e instanceof ValidationFailedException && this.validationFailureShellTitle != null) {
			shellTitle= this.validationFailureShellTitle;
		}
		showWarningDialog(e.getLocalizedMessage(), shellTitle);
	}
	
	/**
	 * Shows a warning dialog if the conversion or the validation returned an error message.
	 * Otherwise nothing happens.
	 */
	protected void showWarningDialog(final String dialogMessage, final String dialogTitle) {
		if (!isWarningDialogActive()) {
			//conversion/validation failed - so open dialog with error message
			
			if (dialogMessage != null) {
				final String[] buttonLabels= this.allowCommit ?
						new String[] {this.changeButtonLabel, this.discardButtonLabel, this.commitButtonLabel} :
						new String[] {this.changeButtonLabel, this.discardButtonLabel};
				final MessageDialog warningDialog= new MessageDialog(
						Display.getCurrent().getActiveShell(), 
						dialogTitle, 
						null, 
						dialogMessage, 
						MessageDialog.WARNING, 
						buttonLabels, 
						0);
				
				//if discard was selected close the editor
				final long returnCode= warningDialog.open();
				if (returnCode == 1) {
					this.editor.close();
				}
				//if commit was selected, commit the value by skipping the validation
				else if (returnCode == 2) {
					this.editor.commit(null, true, true);
				}
			}
		}
	}
	
	/**
	 * Checks if the current active Shell is a conversion/validation failure warning dialog.
	 * As a Shell has not id it is checked if the Shell title is for conversion or validation
	 * failure in localized format.
	 * @return <code>true</code> if a warning dialog is active
	 */
	protected boolean isWarningDialogActive() {
		//check if the current active shell is a conversion or validation failure warning dialog
		final Shell control= Display.getCurrent().getActiveShell();
		if (control != null &&
				(this.conversionFailureShellTitle.equals(control.getText())
						|| this.validationFailureShellTitle.equals(control.getText())
						|| this.failureShellTitle.equals(control.getText()))) {
			return true;
		}
		return false;
	}

	/**
	 * @return The shell title that will be used if there is no conversion or validation shell 
	 * 			title configured.
	 */
	public String getFailureShellTitle() {
		return this.failureShellTitle;
	}

	/**
	 * @param failureShellTitle The shell title that should be used if there is no conversion or 
	 * 			validation shell title configured.
	 */
	public void setFailureShellTitle(final String failureShellTitle) {
		this.failureShellTitle= failureShellTitle;
	}

	/**
	 * @return The shell title that will be used in case this {@link DialogErrorHandling} is called 
	 * 			to handle a {@link ConversionFailedException}.
	 */
	public String getConversionFailureShellTitle() {
		return this.conversionFailureShellTitle;
	}

	/**
	 * @param conversionFailureShellTitle The shell title that should be used in case this 
	 * 			{@link DialogErrorHandling} is called to handle a {@link ConversionFailedException}.
	 */
	public void setConversionFailureShellTitle(final String conversionFailureShellTitle) {
		this.conversionFailureShellTitle= conversionFailureShellTitle;
	}

	/**
	 * @return The shell title that will be used in case this {@link DialogErrorHandling} is called to handle
	 * 			a {@link ValidationFailedException}.
	 */
	public String getValidationFailureShellTitle() {
		return this.validationFailureShellTitle;
	}

	/**
	 * @param validationFailureShellTitle The shell title that should be used in case this 
	 * 			{@link DialogErrorHandling} is called to handle a {@link ValidationFailedException}.
	 */
	public void setValidationFailureShellTitle(final String validationFailureShellTitle) {
		this.validationFailureShellTitle= validationFailureShellTitle;
	}

	/**
	 * @return The text on the button for changing the entered value.
	 */
	public String getChangeButtonLabel() {
		return this.changeButtonLabel;
	}

	/**
	 * @param changeButtonLabel The text on the button for changing the entered value.
	 */
	public void setChangeButtonLabel(final String changeButtonLabel) {
		this.changeButtonLabel= changeButtonLabel;
	}

	/**
	 * @return The text on the button to discard the entered value.
	 */
	public String getDiscardButtonLabel() {
		return this.discardButtonLabel;
	}

	/**
	 * @param discardButtonLabel The text on the button to discard the entered value.
	 */
	public void setDiscardButtonLabel(final String discardButtonLabel) {
		this.discardButtonLabel= discardButtonLabel;
	}

}