fixed build process and added project configuration files from idea

src/main/java/dev/sillyangel/calc/Calculator.java

@@ -44,7 +44,7 @@ public class Calculator extends JFrame implements KeyListener {
 	protected double result;
 	private String[] CalculatorModes = new String[] {"Standard", "Scientific", "Data calculation"};
 	private JComboBox<String> modeselect;
-	
+
 	public static void main(String[] args) {
 		FlatMacDarkLaf.setup();
 		try {
@@ -76,22 +76,22 @@ public class Calculator extends JFrame implements KeyListener {
 		icons.add(Toolkit.getDefaultToolkit().getImage(Calculator.class.getResource("/images/appIcon512.png")));
 		icons.add(Toolkit.getDefaultToolkit().getImage(Calculator.class.getResource("/images/appIcon1024.png")));
 		setIconImages(icons);
-		
+
 		setTitle("angel's awesome calculator");
 		setBounds(100, 100, 368, 556);
 		setFocusable(true);
 		addKeyListener(this);
-        
+
 		contentPane = new JPanel();
 		contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
 		setContentPane(contentPane);
-		
+
 		display = new JTextField();
 		display.setEditable(false);
 		display.setFont(new Font("Segoe UI", Font.PLAIN, 22));
 		display.setColumns(10);
 		JPanel buttonPanel = new JPanel();
-		
+
 		addComponentListener(new ComponentAdapter() {
 			@Override
 			public void componentResized(ComponentEvent e) {
@@ -99,7 +99,7 @@ public class Calculator extends JFrame implements KeyListener {
 				System.out.println("Window resized to " + size.width + "x" + size.height);
 			}
 		});
-		
+
 		JPanel panel = new JPanel();
 		GroupLayout gl_contentPane = new GroupLayout(contentPane);
 		gl_contentPane.setHorizontalGroup(
@@ -119,10 +119,10 @@ public class Calculator extends JFrame implements KeyListener {
 					.addPreferredGap(ComponentPlacement.RELATED)
 					.addComponent(display, GroupLayout.PREFERRED_SIZE, 78, GroupLayout.PREFERRED_SIZE)
 					.addGap(27)
-					.addComponent(buttonPanel, GroupLayout.PREFERRED_SIZE, 359, GroupLayout.PREFERRED_SIZE) 	
+					.addComponent(buttonPanel, GroupLayout.PREFERRED_SIZE, 359, GroupLayout.PREFERRED_SIZE)
 					.addContainerGap(199, Short.MAX_VALUE))
 		);
-		
+
 		buttonPanel.setLayout(new GridLayout(0, 4, 0, 0));
 
 		modeselect = new JComboBox<>(CalculatorModes);
@@ -134,22 +134,26 @@ public class Calculator extends JFrame implements KeyListener {
 			}
 		});
 		modeselect.setEditable(false);
-		
-		JButton btnNewButton_1 = new JButton("New button");
-		JLabel lblNewLabel = new JLabel("New label");
+		modeselect.setFocusable(false);
+
+		JButton btnNewButton_1 = new JButton("New button");
+		btnNewButton_1.setFocusable(false);
+		JLabel lblNewLabel = new JLabel("New label");
+		lblNewLabel.setFocusable(false);
+
 
-		
 		panel.add(modeselect);
 		panel.add(lblNewLabel);
 		panel.add(btnNewButton_1);
 
-		JButton empty_4 = new JButton("");
-		JButton empty_1 = new JButton("");
-		JButton empty_2 = new JButton("");
-		JButton empty = new JButton("");
-		JButton empty_3 = new JButton("");
-		
-		JButton btnErase = new JButton("DEL");
+		JButton btnPercent = new JButton("%");
+		JButton btnClearEntry = new JButton("CE");
+		JButton btnReciprocal = new JButton("1/x");
+		JButton btnSquare = new JButton("x²");
+		JButton btnSquareRoot = new JButton("√x");
+
+		// Use FlatLaf Tree.icon.collapsed as backspace-like icon (or just use text)
+		JButton btnBackspace = new JButton("⌫");
 		JButton btnClear = new JButton("C");
 		JButton btnPlusMin = new JButton("+/-");
 		JButton btnDot = new JButton(".");
@@ -162,7 +166,7 @@ public class Calculator extends JFrame implements KeyListener {
 		JButton btn4 = new JButton("4");
 		JButton btn5 = new JButton("5");
 		JButton btn6 = new JButton("6"); // why was 6 afraid of 7... because 7 8 9 :sob:
-		JButton btn7 = new JButton("7"); // 67! 
+		JButton btn7 = new JButton("7"); // 67!
 		JButton btn8 = new JButton("8");
 		JButton btn9 = new JButton("9");
 
@@ -174,9 +178,9 @@ public class Calculator extends JFrame implements KeyListener {
 		btnDot.addActionListener(new ActionListener() {
 			public void actionPerformed(ActionEvent e) {
 				String n = display.getText(); // get the text on the display
-				if (n.contains(".")) return; // if it already contains a "." skip rest of this 
+				if (n.contains(".")) return; // if it already contains a "." skip rest of this
 				processDigit(e.getActionCommand());
-				
+
 			}
 		});
 
@@ -185,19 +189,25 @@ public class Calculator extends JFrame implements KeyListener {
 				math();
 			}
 		});
-		
-		btnErase.addActionListener(new ActionListener() {
+
+		btnBackspace.addActionListener(new ActionListener() {
 			public void actionPerformed(ActionEvent e) {
-				clear();
+				backspace();
 			}
 		});
-		
+
+		btnClearEntry.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				clearEntry();
+			}
+		});
+
 		btnClear.addActionListener(new ActionListener() {
 			public void actionPerformed(ActionEvent e) {
-				clear();
+				clearAll();
 			}
 		});
-		
+
 		btnPlus.addActionListener(new ActionListener() {
 			public void actionPerformed(ActionEvent e) {
 				setOperator(e.getActionCommand());
@@ -208,8 +218,8 @@ public class Calculator extends JFrame implements KeyListener {
 			public void actionPerformed(ActionEvent e) {
 				setOperator(e.getActionCommand());
 			}
-		});		
-		
+		});
+
 		btnMul.addActionListener(new ActionListener() {
 			public void actionPerformed(ActionEvent e) {
 				setOperator(e.getActionCommand());
@@ -245,13 +255,13 @@ public class Calculator extends JFrame implements KeyListener {
 				processDigit(e.getActionCommand());
 			}
 		});
-		
+
 		btn4.addActionListener(new ActionListener() {
 			public void actionPerformed(ActionEvent e) {
 				processDigit(e.getActionCommand());
 			}
 		});
-		
+
 		btn5.addActionListener(new ActionListener() {
 			public void actionPerformed(ActionEvent e) {
 				processDigit(e.getActionCommand());
@@ -268,37 +278,62 @@ public class Calculator extends JFrame implements KeyListener {
 				processDigit(e.getActionCommand());
 			}
 		});
-		
+
 		btn8.addActionListener(new ActionListener() {
 			public void actionPerformed(ActionEvent e) {
 				processDigit(e.getActionCommand());
 			}
 		});
-		
+
 		btn9.addActionListener(new ActionListener() {
 			public void actionPerformed(ActionEvent e) {
 				processDigit(e.getActionCommand());
 			}
 		});
-		
+
 		btnPlusMin.addActionListener(new ActionListener() {
 		    public void actionPerformed(ActionEvent e) {
 		        String tmp = display.getText();
 		        if (tmp == null || tmp.isEmpty()) return;
 		        char first = tmp.charAt(0);
 		        if (first == '-') {
-		            tmp = tmp.substring(1, tmp.length()); 
+		            tmp = tmp.substring(1, tmp.length());
 		            display.setText(tmp);
 		        } else {
 		            display.setText("-" + tmp);
 		        }
 		    }
 		});
-		
-		
 
-		btnErase.setFont(new Font("Segoe UI", Font.PLAIN, 29));
+		btnPercent.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				setOperator("%");
+			}
+		});
+
+		btnReciprocal.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				reciprocal();
+			}
+		});
+
+		btnSquare.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				square();
+			}
+		});
+
+		btnSquareRoot.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				squareRoot();
+			}
+		});
+
+
+
+		btnBackspace.setFont(new Font("Segoe UI", Font.PLAIN, 29));
 		btnClear.setFont(new Font("Segoe UI", Font.PLAIN, 29));
+		btnClearEntry.setFont(new Font("Segoe UI", Font.PLAIN, 29));
 		btnPlusMin.setFont(new Font("Segoe UI", Font.PLAIN, 29));
 		btnEq.setFont(new Font("Segoe UI", Font.PLAIN, 29));
 		btnDot.setFont(new Font("Segoe UI", Font.PLAIN, 29));
@@ -316,20 +351,44 @@ public class Calculator extends JFrame implements KeyListener {
 		btnMin.setFont(new Font("Segoe UI", Font.PLAIN, 29));
 		btnDiv.setFont(new Font("Segoe UI", Font.PLAIN, 29));
 		btnPlus.setFont(new Font("Segoe UI", Font.PLAIN, 29));
+		btnPercent.setFont(new Font("Segoe UI", Font.PLAIN, 29));
+		btnReciprocal.setFont(new Font("Segoe UI", Font.PLAIN, 29));
+		btnSquare.setFont(new Font("Segoe UI", Font.PLAIN, 29));
+		btnSquareRoot.setFont(new Font("Segoe UI", Font.PLAIN, 29));
 
-		empty.setEnabled(false);
-		empty_1.setEnabled(false);
-		empty_2.setEnabled(false);
-		empty_3.setEnabled(false);
-		empty_4.setEnabled(false);
+		// Make all buttons non-focusable so keyboard input always goes to the frame
+		btnBackspace.setFocusable(false);
+		btnClear.setFocusable(false);
+		btnClearEntry.setFocusable(false);
+		btnPlusMin.setFocusable(false);
+		btnEq.setFocusable(false);
+		btnDot.setFocusable(false);
+		btn0.setFocusable(false);
+		btn1.setFocusable(false);
+		btn2.setFocusable(false);
+		btn3.setFocusable(false);
+		btn4.setFocusable(false);
+		btn5.setFocusable(false);
+		btn6.setFocusable(false);
+		btn7.setFocusable(false);
+		btn8.setFocusable(false);
+		btn9.setFocusable(false);
+		btnMul.setFocusable(false);
+		btnMin.setFocusable(false);
+		btnDiv.setFocusable(false);
+		btnPlus.setFocusable(false);
+		btnPercent.setFocusable(false);
+		btnReciprocal.setFocusable(false);
+		btnSquare.setFocusable(false);
+		btnSquareRoot.setFocusable(false);
 
-		buttonPanel.add(empty);
-		buttonPanel.add(empty_3);
+		buttonPanel.add(btnPercent);
+		buttonPanel.add(btnClearEntry);
 		buttonPanel.add(btnClear);
-		buttonPanel.add(btnErase);
-		buttonPanel.add(empty_4);
-		buttonPanel.add(empty_1);
-		buttonPanel.add(empty_2);
+		buttonPanel.add(btnBackspace);
+		buttonPanel.add(btnReciprocal);
+		buttonPanel.add(btnSquare);
+		buttonPanel.add(btnSquareRoot);
 		buttonPanel.add(btnDiv);
 		buttonPanel.add(btn7);
 		buttonPanel.add(btn8);
@@ -347,7 +406,7 @@ public class Calculator extends JFrame implements KeyListener {
 		buttonPanel.add(btn0);
 		buttonPanel.add(btnDot);
 		buttonPanel.add(btnEq);
-		
+
 		contentPane.setLayout(gl_contentPane);
 
 	}
@@ -362,7 +421,7 @@ public class Calculator extends JFrame implements KeyListener {
 		}
 	}
 
-	void clear() {
+	void backspace() {
 		String tmp = display.getText();
 		if (tmp.length()>1) // if there is more than 1 character
 		    display.setText( tmp.substring(0, tmp.length()-1) );
@@ -370,11 +429,56 @@ public class Calculator extends JFrame implements KeyListener {
 		    display.setText("");
 	}
 
+	void clearEntry() {
+		// Clear only the current display (entry)
+		display.setText("");
+	}
+
+	void clearAll() {
+		// Clear everything including operands and operator
+		display.setText("");
+		operand1 = "";
+		operand2 = "";
+		operator = "";
+		resultVisible = false;
+	}
+
+	void reciprocal() {
+		String tmp = display.getText();
+		if (tmp == null || tmp.isEmpty()) return;
+		double value = Double.parseDouble(tmp);
+		if (value != 0) {
+			result = 1.0 / value;
+			display.setText("" + result);
+			resultVisible = true;
+		}
+	}
+
+	void square() {
+		String tmp = display.getText();
+		if (tmp == null || tmp.isEmpty()) return;
+		double value = Double.parseDouble(tmp);
+		result = value * value;
+		display.setText("" + result);
+		resultVisible = true;
+	}
+
+	void squareRoot() {
+		String tmp = display.getText();
+		if (tmp == null || tmp.isEmpty()) return;
+		double value = Double.parseDouble(tmp);
+		if (value >= 0) {
+			result = Math.sqrt(value);
+			display.setText("" + result);
+			resultVisible = true;
+		}
+	}
+
 	void processDigit(String actionCommand) {
 		if (resultVisible == true) {
 			display.setText("");
 			resultVisible = false;
-		} 
+		}
 		// if (actionCommand == "+") {
 		// 	btnDiv.setForeground(new Color(0, 0, 0));
 		// 	btnMul.setForeground(new Color(0, 0, 0));
@@ -397,19 +501,19 @@ public class Calculator extends JFrame implements KeyListener {
 		// 	btnMin.setForeground(new Color(30, 144, 255));
         // }
 		display.setText(display.getText() + actionCommand);
-		
+
 	}
 	void setOperator(String daop) {
 		operand1 = display.getText();
 		operator = daop;
 		display.setText("");
 	}
-	
+
     void math() {
 		operand2 = display.getText();
 		double op1 = Double.parseDouble(operand1);
 		double op2 = Double.parseDouble(operand2);
-		
+
 		if (operator == "+") {
 			result = op1+op2;
 		} else if (operator == "-") {
@@ -418,25 +522,27 @@ public class Calculator extends JFrame implements KeyListener {
 			result = op1*op2;
 		} else if (operator == "/") {
 			result = op1/op2;
+		} else if (operator == "%") {
+			result = op1 % op2;
 		} else {
 			result = op2;
 			System.out.println("Op: " + op1);
 			System.out.println("Op2: " + op2);
 		}
-		
+
 		operator = "";
 		operand1 = "";
 		operand2 = "";
-		
+
 		// btnDiv.setForeground(new Color(0, 0, 0));
 		// btnMul.setForeground(new Color(0, 0, 0));
 		// btnPlus.setForeground(new Color(0, 0, 0));
 		// btnMin.setForeground(new Color(0, 0, 0));
-		
+
 		resultVisible = true;
 		display.setText(""+result);
 	}
-	
+
     // Implement the keyPressed method
     @Override
     public void keyPressed(KeyEvent e) {
@@ -445,14 +551,14 @@ public class Calculator extends JFrame implements KeyListener {
        if (KeyEvent.getKeyText(keyCode) == "Enter") {
     	   math();
        } else if (e.getKeyCode() == KeyEvent.VK_BACK_SPACE) {
-    	   clear();
+    	   backspace();
        }
     }
 
     // Implement the keyReleased method
     @Override
     public void keyReleased(KeyEvent e) {
-//        int keyCode = e.getKeyCode();	
+//        int keyCode = e.getKeyCode();
 //       System.out.println("Key Released: " + KeyEvent.getKeyText(keyCode));
     }
 
@@ -477,6 +583,6 @@ public class Calculator extends JFrame implements KeyListener {
         if (c == '=') {
         	math();
         }
-        
+
     }
-}
+}