[client] Add resource loader that will take care of error handling

1 files changed, 95 insertions, 0 deletions

diff --git a/dozentenmodul/src/main/java/util/ResourceLoader.java b/dozentenmodul/src/main/java/util/ResourceLoader.java
new file mode 100644
index 00000000..06200e5a
--- /dev/null
+++ b/dozentenmodul/src/main/java/util/ResourceLoader.java
@@ -0,0 +1,95 @@
+package util;
+
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Graphics2D;
+import java.awt.font.FontRenderContext;
+import java.awt.geom.Rectangle2D;
+import java.awt.image.BufferedImage;
+import java.net.URL;
+
+import javax.swing.ImageIcon;
+
+/**
+ * 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 {
+
+	/**
+	 * 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) {
+			System.out.println("Resource not found: " + path);
+		} else {
+			try {
+				return new ImageIcon(url, description);
+			} catch (Exception e) {
+				System.out.println("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();
+		}
+	}
+	
+	/**
+	 * 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");
+	}
+
+}