Groovy example source code file (OutputTransforms.groovy)

This example Groovy source code file (OutputTransforms.groovy) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

awt, closure, component, file, file, graphicsenvironment, groovyshell, groovyshell, gui, icon, icon, image, image, imageicon, imageicon, object, outputtransforms, swing

The Groovy OutputTransforms.groovy source code

/*
 * Copyright 2003-2008 the original author or authors.
 *
 * 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 groovy.ui

import java.awt.*
import java.awt.image.BufferedImage
import javax.swing.Icon
import javax.swing.ImageIcon
import org.codehaus.groovy.runtime.InvokerHelper

public class OutputTransforms {

    @Lazy static def localTransforms = loadOutputTransforms()

    static def loadOutputTransforms() {
        def transforms = []

        //
        // load user local transforms
        //
        def userHome = new File(System.getProperty('user.home'))
        def groovyDir = new File(userHome, '.groovy')
        def userTransforms = new File(groovyDir, "OutputTransforms.groovy")
        if (userTransforms.exists()) {
            GroovyShell shell = new GroovyShell()
            shell.setVariable('transforms', transforms)
            shell.evaluate(userTransforms)
        }

        //
        // built-in transforms
        //

        // any non-window GUI components, such as  a heavyweight button or a
        // Swing component, gets passed if it has no parent set (the parent
        // clause is to keep buttons from disappearing from user shown forms)
        transforms << { it -> if ((it instanceof Component) && !(it instanceof Window) && (it.parent == null)) it }

        // remaining components get printed to an image
        transforms << { it ->
            if (it instanceof javax.swing.JComponent) {
                Dimension d = it.size
                if (d.width == 0) {
                    d = it.preferredSize
                    it.size = d
                }

                GraphicsEnvironment ge = GraphicsEnvironment.localGraphicsEnvironment
                GraphicsDevice gs = ge.defaultScreenDevice
                GraphicsConfiguration gc = gs.defaultConfiguration

                BufferedImage image = gc.createCompatibleImage(d.width as int, d.height as int, Transparency.TRANSLUCENT)
                Graphics2D g2 = image.createGraphics()
                it.print(g2)
                g2.dispose()
                new ImageIcon(image)
            }
        }

        // icons get passed, they can be rendered multiple times so no parent check
        transforms << { it -> if (it instanceof Icon) it }

        // Images become ImageIcons
        transforms << { it -> if (it instanceof Image) new ImageIcon(it)}

        // final case, non-nulls just get inspected as strings
        transforms << { it -> if (it != null) "${InvokerHelper.inspect(it)}" }

        return transforms
    }

    static def transformResult(def base, def transforms = localTransforms) {
        for (Closure c : transforms) {
            def result = c(base as Object)
            if (result != null)  {
                return result
            }
        }
        return base
    }

}