praktikum-holons/src/holeg/ui/view/window/AddOnWindow.java

package holeg.ui.view.window;

import holeg.api.AddOn;
import holeg.preferences.ImagePreference;
import holeg.ui.controller.Control;
import holeg.ui.view.image.Import;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Font;
import java.io.File;
import java.io.FileNotFoundException;
import java.lang.reflect.InvocationTargetException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Scanner;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextPane;
import javax.swing.filechooser.FileNameExtensionFilter;
import javax.swing.text.SimpleAttributeSet;
import javax.swing.text.StyleConstants;
import javax.tools.JavaCompiler;
import javax.tools.ToolProvider;

/**
 * This window is for the loading of additional add-ons like algorithm or randomizer.
 */
public class AddOnWindow extends JFrame {

  private final Control control;
  private final JPanel content = new JPanel();

  public AddOnWindow(JFrame parentFrame, Control control) {
    this.control = control;
    this.setTitle("Add-Ons");
    this.setVisible(true);
    this.setContentPane(content);
    this.setIconImage(Import.loadImage(ImagePreference.Logo, 30, 30));
    initMenuBar();
    initDefaultContentPanel();
    this.pack();
    this.setLocationRelativeTo(parentFrame);
  }

  private void initMenuBar() {
    JMenuBar menuBar = new JMenuBar();
    JMenu menuSelect = new JMenu("File");
    JMenuItem menuItemAlgorithm = new JMenuItem("Open .java-File..");
    menuItemAlgorithm.addActionListener(actionEvent -> openJavaFile());
    menuSelect.add(menuItemAlgorithm);
    JMenuItem menuItemFolder = new JMenuItem("Open Folder..");
    menuItemFolder.addActionListener(actionEvent -> openFolder(menuSelect));
    menuSelect.add(menuItemFolder);
    menuSelect.addSeparator();
    JMenu menuHelp = new JMenu("Help");
    menuBar.add(menuSelect);
    menuBar.add(menuHelp);
    this.setJMenuBar(menuBar);
  }

  private void initDefaultContentPanel() {
    content.setLayout(new BorderLayout());
    JTextPane textPane = new JTextPane();
    SimpleAttributeSet attribs = new SimpleAttributeSet();
    StyleConstants.setAlignment(attribs, StyleConstants.ALIGN_JUSTIFIED);
    textPane.setParagraphAttributes(attribs, true);
    textPane.setText("No algorithm is loaded."
        + "\n OPTION[1]:"
        + "\n  Select '.java'-file via the file browser. (File\u2192Open .jave-File..)"
        + "\n"
        + "\n OPTION[2]:"
        + "\n First select the folder where the addon '.java'-file is located. (File\u2192Open Folder..)"
        + "\n Second load the algorithm. (File\u2192'YourAlgo')");
    textPane.setFont(new Font("Serif", Font.PLAIN, 16));

    content.add(textPane, BorderLayout.CENTER);
    content.setPreferredSize(new Dimension(500, 500));
  }

  /**
   *
   */
  private void openJavaFile() {
    JFileChooser fileChooser = new JFileChooser();
    fileChooser.setCurrentDirectory(
        new File(System.getProperty("user.dir") + "/src/holeg/algorithm/"));
    fileChooser.setFileFilter(new FileNameExtensionFilter("JAVA Source Files", "java"));
    fileChooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
    fileChooser.setAcceptAllFileFilterUsed(false);
    int result = fileChooser.showOpenDialog(this);
    if (result == JFileChooser.APPROVE_OPTION) {
      //Found a file
      loadAlgorithm(fileChooser.getSelectedFile());
    }
  }

  private void openFolder(JMenu menuSelect) {
    JFileChooser fileChooser = new JFileChooser();
    fileChooser.setCurrentDirectory(new File(System.getProperty("user.dir") + "/src/"));
    fileChooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
    fileChooser.setAcceptAllFileFilterUsed(false);
    int result = fileChooser.showOpenDialog(this);
    if (result == JFileChooser.APPROVE_OPTION) {
      File[] files = fileChooser.getSelectedFile()
          .listFiles(file -> file.getName().endsWith(".java"));

      //Remove all Index from old Folder
      for (int i = menuSelect.getItemCount() - 1; i > 2; i--) {
        menuSelect.remove(i);
      }
      for (File file : files) {
        JMenuItem insertMenuItem = new JMenuItem(getNameWithoutExtension(file));
        insertMenuItem.addActionListener(actionEvent -> loadAlgorithm(file));
        menuSelect.add(insertMenuItem);
      }
    }
  }

  /**
   * Compile and load a java File.
   * @param javaFile file
   */

  private void loadAlgorithm(File javaFile) {
    //Get Class name:
    String name = getNameWithoutExtension(javaFile);
    //get Package name
    String packageName = "";
    Scanner in = null;
    try {
      in = new Scanner(javaFile);
      while (in.hasNext()) {
        String line = in.nextLine().trim();
        if (line.startsWith("package")) {
          packageName = line.substring(8, line.length() - 1);
          break;
        }
      }
    } catch (FileNotFoundException e) {
      generateErrorDialog("File not Found");
    }
    //GetPathName
    //String path =  javaFile.getParentFile().isDirectory() ? javaFile.getParentFile().getAbsolutePath() : "";
    File folder = javaFile.getParentFile();
    // Compile source file.
    JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
    if (ToolProvider.getSystemJavaCompiler() == null) {
      generateErrorDialog("Please install the JDK on your system.");
    } else {
      compiler.run(null, null, null, javaFile.getAbsolutePath());
    }
    try {
      URLClassLoader classLoader = URLClassLoader.newInstance(new URL[]{folder.toURI().toURL()});
      Class<?> cls = Class.forName(packageName.isEmpty() ? name : packageName + "." + name, true,
          classLoader);
      Object object = cls.getDeclaredConstructor().newInstance();
      if (object instanceof AddOn addon) {
        addon.setController(control);
        this.setContentPane(addon.getPanel());
        this.pack();
      } else {
        generateErrorDialog("Class does not implement CpsAlgorithm!");
      }
    } catch (MalformedURLException e) {
      generateErrorDialog("URLClassLoader error");
    } catch (ClassNotFoundException e) {
      generateErrorDialog("ClassNotFound error" + e.getMessage());
    } catch (InstantiationException e) {
      generateErrorDialog("Class does not implement a Constructor." + e.getMessage());
    } catch (IllegalAccessException e) {
      generateErrorDialog(
          "Class set this method privat or protected needs to be public." + e.getMessage());
    } catch (IllegalArgumentException | InvocationTargetException | NoSuchMethodException | SecurityException e) {
      e.printStackTrace();
    }
  }

  /**
   * Returns the Name of a file without Extension.
   * @param file the file
   * @return filename without extension like ".java"
   */
  private String getNameWithoutExtension(File file) {
    return file.getName().substring(0, file.getName().lastIndexOf("."));
  }

  /**
   * Generate a little Error Dialog to inform the User.
   * @param message error message
   */
  private void generateErrorDialog(String message) {
    JOptionPane.showConfirmDialog(this, message, "Error", JOptionPane.YES_NO_OPTION,
        JOptionPane.ERROR_MESSAGE);
  }
}