org.drools.guvnor.client.common.AbstractRestrictedEntryTextBox.java Source code

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Here is the source code for org.drools.guvnor.client.common.AbstractRestrictedEntryTextBox.java

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/*
 * Copyright 2011 JBoss 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 org.drools.guvnor.client.common;

import com.google.gwt.event.dom.client.BlurEvent;
import com.google.gwt.event.dom.client.BlurHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.event.logical.shared.ValueChangeEvent;
import com.google.gwt.user.client.ui.TextBox;

/**
 * A TextBox to handle restricted entry
 */
public abstract class AbstractRestrictedEntryTextBox extends TextBox {

    protected final boolean allowEmptyValue;

    public AbstractRestrictedEntryTextBox() {
        this(false);
    }

    public AbstractRestrictedEntryTextBox(final boolean allowEmptyValue) {
        this.allowEmptyValue = allowEmptyValue;
        setup();
    }

    protected void setup() {
        final TextBox me = this;

        //Validate value as it is entered
        this.addKeyPressHandler(new KeyPressHandler() {

            public void onKeyPress(KeyPressEvent event) {

                // Permit navigation
                int keyCode = event.getNativeEvent().getKeyCode();
                if (event.isControlKeyDown() || keyCode == KeyCodes.KEY_BACKSPACE || keyCode == KeyCodes.KEY_DELETE
                        || keyCode == KeyCodes.KEY_LEFT || keyCode == KeyCodes.KEY_RIGHT
                        || keyCode == KeyCodes.KEY_TAB) {
                    return;
                }

                // Get new value and validate
                int charCode = event.getCharCode();
                String oldValue = me.getValue();
                String newValue = oldValue.substring(0, me.getCursorPos());
                newValue = newValue + ((char) charCode);
                newValue = newValue + oldValue.substring(me.getCursorPos() + me.getSelectionLength());
                if (!isValidValue(newValue, false)) {
                    event.preventDefault();
                }

            }

        });

        //Add validation when looses focus (for when values are pasted in by users')
        this.addBlurHandler(new BlurHandler() {

            @Override
            public void onBlur(BlurEvent event) {
                final String value = me.getText();
                if (!isValidValue(value, true)) {
                    final String validValue = makeValidValue(value);
                    me.setText(validValue);
                    ValueChangeEvent.fire(AbstractRestrictedEntryTextBox.this, validValue);
                }
            }

        });

    }

    /**
     * Validate value of TextBox
     * 
     * @param value
     * @param isOnFocusLost
     *            Focus has been lost from the TextBox
     * @return True if valid
     */
    public abstract boolean isValidValue(String value, boolean isOnFocusLost);

    /**
     * If validation fails (e.g. as a result of a user pasting a value) when the
     * TextBox looses focus this method is called to transform the current value
     * into one which is valid. This default implementation returns an empty
     * String, however numerical TextBoxes could check the value is numerical
     * and scale to that suitable for the type.
     * 
     * @param value
     *            Current value
     * @return A valid value
     */
    protected String makeValidValue(String value) {
        return "";
    }

}