moved ResourceLoader from dozmod to mss

2 files changed, 182 insertions, 1 deletions

diff --git a/pom.xml b/pom.xml
index 6527be3..9e6b6d2 100644
--- a/pom.xml
+++ b/pom.xml
@@ -110,6 +110,11 @@
 			<version>2.8.1</version>
 			<scope>compile</scope>
 		</dependency>
-
+		<dependency>
+			<groupId>commons-io</groupId>
+			<artifactId>commons-io</artifactId>
+			<version>2.5</version>
+			<scope>compile</scope>
+		</dependency>
 	</dependencies>
 </project>
diff --git a/src/main/java/org/openslx/util/ResourceLoader.java b/src/main/java/org/openslx/util/ResourceLoader.java
new file mode 100644
index 0000000..7f829fc
--- /dev/null
+++ b/src/main/java/org/openslx/util/ResourceLoader.java
@@ -0,0 +1,176 @@
+package org.openslx.util;
+
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.Font;
+import java.awt.Graphics2D;
+import java.awt.Image;
+import java.awt.RenderingHints;
+import java.awt.font.FontRenderContext;
+import java.awt.geom.Rectangle2D;
+import java.awt.image.BufferedImage;
+import java.io.InputStream;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.swing.Icon;
+import javax.swing.ImageIcon;
+
+import org.apache.commons.io.IOUtils;
+import org.apache.log4j.Logger;
+
+/**
+ * Helper class for loading resources.
+ * This should be error safe loaders with a fall back in case the
+ * requested resource can't be found, or isn't of the expected type.
+ */
+public class ResourceLoader
+{
+
+	/**
+	 * Logger for this class
+	 */
+	private final static Logger LOGGER = Logger.getLogger( ResourceLoader.class );
+
+	/**
+	 * Load the given resource as an ImageIcon.
+	 * This is guaranteed to never throw an Exception and always return
+	 * an ImageIcon. If the requested resource could not be loaded,
+	 * an icon is generated, containing an error message. If even that
+	 * fails, an empty icon is returned.
+	 *
+	 * @param path Resource path to load
+	 * @param description Icon description
+	 * @return ImageIcon instance
+	 */
+	public static ImageIcon getIcon( String path, String description )
+	{
+		URL url = ResourceLoader.class.getResource( path );
+		if ( url == null ) {
+			LOGGER.error( "Resource not found: " + path );
+		} else {
+			try {
+				return new ImageIcon( url, description );
+			} catch ( Exception e ) {
+				LOGGER.error( "Resource not loadable: " + path );
+			}
+		}
+		// If we reach here loading failed, create image containing error
+		// message
+		try {
+			return errorIcon( "Invalid Resource: " + path );
+		} catch ( Throwable t ) {
+			return new ImageIcon();
+		}
+	}
+
+	public static Icon getIcon( String path, String description, int maxHeight, Component context )
+	{
+		ImageIcon icon = getIcon( path, description );
+		return getScaledIcon( icon, maxHeight, context );
+	}
+
+	/**
+	 * Load the given resource as an ImageIcon.
+	 * This is guaranteed to never throw an Exception and always return
+	 * an ImageIcon. If the requested resource could not be loaded,
+	 * an icon is generated, containing an error message. If even that
+	 * fails, an empty icon is returned.
+	 *
+	 * @param path Resource path to load
+	 * @return ImageIcon instance
+	 */
+	public static ImageIcon getIcon( String path )
+	{
+		return getIcon( path, path );
+	}
+
+	/**
+	 * Helper that will create an icon with given text.
+	 *
+	 * @param errorText Text to render to icon
+	 * @return the icon
+	 */
+	private static ImageIcon errorIcon( String errorText )
+	{
+		Font font = new Font( "Tahoma", Font.PLAIN, 20 );
+
+		// get dimensions of text
+		FontRenderContext frc = new FontRenderContext( null, true, true );
+		Rectangle2D bounds = font.getStringBounds( errorText, frc );
+		int w = (int)bounds.getWidth();
+		int h = (int)bounds.getHeight();
+
+		// create a BufferedImage object
+		BufferedImage image = new BufferedImage( w, h, BufferedImage.TYPE_INT_RGB );
+		Graphics2D g = image.createGraphics();
+
+		// set color and other parameters
+		g.setColor( Color.WHITE );
+		g.fillRect( 0, 0, w, h );
+		g.setColor( Color.RED );
+		g.setFont( font );
+
+		g.drawString( errorText, (float)bounds.getX(), (float) -bounds.getY() );
+
+		g.dispose();
+		return new ImageIcon( image, "ERROR" );
+	}
+
+	/**
+	 * Tries to load the given resource treating it as a text file
+	 *
+	 * @param path Resource path to load
+	 * @return content of the loaded resource as String
+	 */
+	public static String getTextFile( String path )
+	{
+		String fileContent = null;
+		try ( InputStream stream = ResourceLoader.class.getResourceAsStream( path ) ) {
+			fileContent = IOUtils.toString( stream, StandardCharsets.UTF_8 );
+		} catch ( Exception e ) {
+			LOGGER.error( "IO error while trying to load resource '" + path + "'. See trace: ", e );
+		}
+
+		if ( fileContent != null ) {
+			return fileContent;
+		} else {
+			return "Resource '" + path + "' not found.";
+		}
+	}
+
+	public static InputStream getStream( String path )
+	{
+		return ResourceLoader.class.getResourceAsStream( path );
+	}
+
+	private static final Map<Icon, ImageIcon> iconCache = new HashMap<>();
+
+	public static Icon getScaledIcon( Icon icon, int height, Component context )
+	{
+		if ( icon == null )
+			return null;
+		ImageIcon cached = iconCache.get( icon );
+		if ( cached != null && cached.getIconHeight() == height )
+			return cached;
+		// Generate?
+		float iHeight = icon.getIconHeight();
+		float tHeight = height;
+		if ( iHeight <= tHeight )
+			return icon; // Small enough
+		// Scale down:
+		BufferedImage image = new BufferedImage( icon.getIconWidth(), icon.getIconHeight(),
+				BufferedImage.TYPE_INT_ARGB );
+		Graphics2D g = image.createGraphics();
+		g.setRenderingHint( RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY );
+		g.setRenderingHint( RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON );
+		icon.paintIcon( context, g, 0, 0 );
+		ImageIcon scaledIcon = new ImageIcon( image.getScaledInstance(
+				(int) ( icon.getIconWidth() * ( tHeight / iHeight ) ), (int) ( tHeight ), Image.SCALE_SMOOTH ) );
+		iconCache.put( icon, scaledIcon );
+		return scaledIcon;
+	}
+
+}