net.cbtltd.client.field.spinner.ValueSpinner.java Source code

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Here is the source code for net.cbtltd.client.field.spinner.ValueSpinner.java

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/*
 * Copyright 2008 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package net.cbtltd.client.field.spinner;

import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;

/**
 * The Class ValueSpinner is a combination of a {@link TextBox} and a
 * {@link Spinner} to allow spinning and display of the resulting value.
 */
public class ValueSpinner extends HorizontalPanel {

    private Spinner spinner;
    private final TextBox valueBox = new TextBox();

    private SpinnerListener spinnerListener = new SpinnerListener() {
        public void onSpinning(Integer value) {
            if (getSpinner() != null) {
                getSpinner().setValue(value, false);
            }
            valueBox.setText(formatValue(value));
        }
    };

    private KeyPressHandler keyPressHandler = new KeyPressHandler() {

        public void onKeyPress(KeyPressEvent event) {
            int index = valueBox.getCursorPos();
            String previousText = valueBox.getText();
            String newText;
            if (valueBox.getSelectionLength() > 0) {
                newText = previousText.substring(0, valueBox.getCursorPos()) + event.getCharCode() + previousText
                        .substring(valueBox.getCursorPos() + valueBox.getSelectionLength(), previousText.length());
            } else {
                newText = previousText.substring(0, index) + event.getCharCode()
                        + previousText.substring(index, previousText.length());
            }
            valueBox.cancelKey();
            try {
                Integer newValue = parseValue(newText);
                if (spinner.isConstrained() && (newValue > spinner.getMax() || newValue < spinner.getMin())) {
                    return;
                }
                spinner.setValue(newValue, true);
            } catch (Exception e) {
                valueBox.cancelKey();
            }
        }
    };

    /**
     * @param value initial value
     */
    public ValueSpinner(Integer value) {
        this(value, 0, 0, 1, 99, false);
    }

    /**
     * Instantiates a new spinner.
     * 
     * @param value initial value
     * @param min min value
     * @param max max value
     */
    public ValueSpinner(Integer value, int min, int max) {
        this(value, min, max, 1, 99, true);
    }

    /**
     * Instantiates a new spinner.
     * 
     * @param value initial value
     * @param min min value
     * @param max max value
     * @param minStep min value for stepping
     * @param maxStep max value for stepping
     */
    public ValueSpinner(Integer value, int min, int max, int minStep, int maxStep) {
        this(value, min, max, minStep, maxStep, true);
    }

    /**
     * Instantiates a new spinner.
     * 
     * @param value initial value
     * @param min min value
     * @param max max value
     * @param minStep min value for stepping
     * @param maxStep max value for stepping
     * @param constrained if set to false min and max value will not have any effect
     */
    public ValueSpinner(Integer value, Integer min, Integer max, int minStep, int maxStep, boolean constrained) {
        super();
        setStylePrimaryName("gwt-ValueSpinner");
        spinner = new Spinner(spinnerListener, value, min, max, minStep, maxStep, constrained);
        valueBox.setStyleName("textBox");
        valueBox.addKeyPressHandler(keyPressHandler);
        setVerticalAlignment(ALIGN_MIDDLE);
        add(valueBox);
        VerticalPanel arrowsPanel = new VerticalPanel();
        arrowsPanel.setStylePrimaryName("arrows");
        arrowsPanel.setHorizontalAlignment(VerticalPanel.ALIGN_CENTER);
        arrowsPanel.add(spinner.getIncrementArrow());
        arrowsPanel.add(spinner.getDecrementArrow());
        add(arrowsPanel);
    }

    /**
     * @return the Spinner used by this widget
     */
    public Spinner getSpinner() {
        return spinner;
    }

    /**
     * @return the SpinnerListener used to listen to the {@link Spinner} events
     */
    public SpinnerListener getSpinnerListener() {
        return spinnerListener;
    }

    /**
     * @return the TextBox used by this widget
     */
    public TextBox getTextBox() {
        return valueBox;
    }

    /**
     * @return whether this widget is enabled.
     */
    public boolean isEnabled() {
        return spinner.isEnabled();
    }

    /**
     * Sets whether this widget is enabled.
     * 
     * @param enabled true to enable the widget, false to disable it
     */
    public void setEnabled(boolean enabled) {
        spinner.setEnabled(enabled);
        valueBox.setEnabled(enabled);
    }

    /**
     * @param value the value to format
     * @return the formatted value
     */
    protected String formatValue(Integer value) {
        return String.valueOf(value);
    }

    /**
     * @param value the value to parse
     * @return the parsed value
     */
    protected Integer parseValue(String value) {
        return Integer.valueOf(value);
    }
}