Code cleanup

SerialPlotter now uses min/2 and max*2 instead of plain min and max
Ticks works also when min == max
Fixes arduino#3767

Author: Federico Fissore

app/src/processing/app/SerialPlotter.java

@@ -19,54 +19,55 @@
 package processing.app;
 
 import cc.arduino.packages.BoardPort;
+import processing.app.helpers.CircularBuffer;
+import processing.app.helpers.Ticks;
 import processing.app.legacy.PApplet;
 
-import processing.app.helpers.*;
-import static processing.app.I18n.tr;
-
-import java.awt.*;
-import java.awt.event.*;
-import java.awt.geom.*;
 import javax.swing.*;
-import javax.swing.border.*;
+import javax.swing.border.EmptyBorder;
+import java.awt.*;
+import java.awt.event.ActionListener;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.Rectangle2D;
+
+import static processing.app.I18n.tr;
 
 public class SerialPlotter extends AbstractMonitor {
-  private StringBuffer messageBuffer;
-  private CircularBuffer buffer;
-  private GraphPanel graphPanel;
-  private JComboBox serialRates;
 
+  private final StringBuffer messageBuffer;
+  private CircularBuffer buffer;
+  private JComboBox<String> serialRates;
   private Serial serial;
   private int serialRate;
 
   private class GraphPanel extends JPanel {
     private double minY, maxY, rangeY;
     private Rectangle bounds;
     private int xOffset;
-    private Font font;
-    private Color graphColor;
-    
+    private final Font font;
+    private final Color graphColor;
+
     public GraphPanel() {
       font = Theme.getFont("console.font");
       graphColor = Theme.getColor("header.bgcolor");
       xOffset = 20;
     }
-    
+
     @Override
     public void paintComponent(Graphics g1) {
-      Graphics2D g = (Graphics2D)g1;
+      Graphics2D g = (Graphics2D) g1;
       g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
       g.setFont(font);
       super.paintComponent(g);
-      
+
       bounds = g.getClipBounds();
       setBackground(Color.WHITE);
-      if(buffer.isEmpty()) {
+      if (buffer.isEmpty()) {
         return;
       }
-      
-      minY = buffer.min();
-      maxY = buffer.max();
+
+      minY = buffer.min() / 2;
+      maxY = buffer.max() * 2;
       Ticks ticks = new Ticks(minY, maxY, 3);
       minY = Math.min(minY, ticks.getTick(0));
       maxY = Math.max(maxY, ticks.getTick(ticks.getTickCount() - 1));
@@ -77,45 +78,45 @@ public void paintComponent(Graphics g1) {
 
       g.setStroke(new BasicStroke(1.0f));
       FontMetrics fm = g.getFontMetrics();
-      for(int i = 0; i < ticks.getTickCount(); ++i) {
+      for (int i = 0; i < ticks.getTickCount(); ++i) {
         double tick = ticks.getTick(i);
         Rectangle2D fRect = fm.getStringBounds(String.valueOf(tick), g);
-        xOffset = Math.max(xOffset, (int)fRect.getWidth() + 15);
+        xOffset = Math.max(xOffset, (int) fRect.getWidth() + 15);
 
         // draw tick
-        g.drawLine(xOffset - 5, (int)transformY(tick), xOffset + 2, (int)transformY(tick));
+        g.drawLine(xOffset - 5, (int) transformY(tick), xOffset + 2, (int) transformY(tick));
         // draw tick label
-        g.drawString(String.valueOf(tick), xOffset - (int)fRect.getWidth() - 10, transformY(tick) - (float)fRect.getHeight() * 0.5f + fm.getAscent());
+        g.drawString(String.valueOf(tick), xOffset - (int) fRect.getWidth() - 10, transformY(tick) - (float) fRect.getHeight() * 0.5f + fm.getAscent());
       }
 
       g.drawLine(bounds.x + xOffset, bounds.y + 5, bounds.x + xOffset, bounds.y + bounds.height - 10);
-      
-      g.setTransform(AffineTransform.getTranslateInstance(xOffset, 0));		
-      float xstep = (float)(bounds.width - xOffset) / (float)buffer.capacity();
-      
+
+      g.setTransform(AffineTransform.getTranslateInstance(xOffset, 0));
+      float xstep = (float) (bounds.width - xOffset) / (float) buffer.capacity();
+
       g.setColor(graphColor);
       g.setStroke(new BasicStroke(0.75f));
-      
-      for(int i = 0; i < buffer.size() - 1; ++i) {
+
+      for (int i = 0; i < buffer.size() - 1; ++i) {
         g.drawLine(
-          (int)(i * xstep), (int)transformY(buffer.get(i)),
-          (int)((i + 1) * xstep), (int)transformY(buffer.get(i + 1))
+          (int) (i * xstep), (int) transformY(buffer.get(i)),
+          (int) ((i + 1) * xstep), (int) transformY(buffer.get(i + 1))
         );
       }
     }
-    
+
     @Override
     public Dimension getMinimumSize() {
       return new Dimension(200, 100);
     }
-    
+
     @Override
     public Dimension getPreferredSize() {
       return new Dimension(500, 250);
     }
-    
+
     private float transformY(double rawY) {
-      return (float)(5 + (bounds.height - 10) * (1.0 - (rawY - minY) / rangeY));
+      return (float) (5 + (bounds.height - 10) * (1.0 - (rawY - minY) / rangeY));
     }
   }
 
@@ -124,93 +125,80 @@ public SerialPlotter(BoardPort port) {
 
     serialRate = PreferencesData.getInteger("serial.debug_rate");
     serialRates.setSelectedItem(serialRate + " " + tr("baud"));
-    onSerialRateChange(new ActionListener() {
-      public void actionPerformed(ActionEvent event) {
-        String wholeString = (String) serialRates.getSelectedItem();
-        String rateString = wholeString.substring(0, wholeString.indexOf(' '));
-        serialRate = Integer.parseInt(rateString);
-        PreferencesData.set("serial.debug_rate", rateString);
-        try {
-          close();
-          Thread.sleep(100); // Wait for serial port to properly close
-          open();
-        } catch (InterruptedException e) {
-          // noop
-        } catch (Exception e) {
-          System.err.println(e);
-        }
+    onSerialRateChange(event -> {
+      String wholeString = (String) serialRates.getSelectedItem();
+      String rateString = wholeString.substring(0, wholeString.indexOf(' '));
+      serialRate = Integer.parseInt(rateString);
+      PreferencesData.set("serial.debug_rate", rateString);
+      try {
+        close();
+        Thread.sleep(100); // Wait for serial port to properly close
+        open();
+      } catch (Exception e) {
+        // ignore
       }
     });
 
     messageBuffer = new StringBuffer();
   }
-  
+
   protected void onCreateWindow(Container mainPane) {
     mainPane.setLayout(new BorderLayout());
-    
-    Font consoleFont = Theme.getFont("console.font");
-    Font editorFont = PreferencesData.getFont("editor.font");
-    Font font = new Font(consoleFont.getName(), consoleFont.getStyle(), editorFont.getSize());
-   
+
     buffer = new CircularBuffer(500);
-    graphPanel = new GraphPanel();
-    
+    GraphPanel graphPanel = new GraphPanel();
+
     mainPane.add(graphPanel, BorderLayout.CENTER);
-    
+
     JPanel pane = new JPanel();
     pane.setLayout(new BoxLayout(pane, BoxLayout.X_AXIS));
     pane.setBorder(new EmptyBorder(4, 4, 4, 4));
-    
-    serialRates = new JComboBox();
-    for (int i = 0; i < serialRateStrings.length; i++)
-      serialRates.addItem(serialRateStrings[i] + " " + tr("baud"));
-    
+
+    serialRates = new JComboBox<>();
+    for (String serialRateString : serialRateStrings) serialRates.addItem(serialRateString + " " + tr("baud"));
+
     serialRates.setMaximumSize(serialRates.getMinimumSize());
 
     pane.add(Box.createRigidArea(new Dimension(8, 0)));
     pane.add(serialRates);
-    
+
     mainPane.add(pane, BorderLayout.SOUTH);
   }
-  
-  protected void onEnableWindow(boolean enable)
-  {
-    serialRates.setEnabled(enable); 
+
+  protected void onEnableWindow(boolean enable) {
+    serialRates.setEnabled(enable);
   }
-  
-  public void onSerialRateChange(ActionListener listener) {
+
+  private void onSerialRateChange(ActionListener listener) {
     serialRates.addActionListener(listener);
   }
-  
+
   public void message(final String s) {
     messageBuffer.append(s);
-    while(true) {
+    while (true) {
       int linebreak = messageBuffer.indexOf("\n");
-      if(linebreak == -1) {
+      if (linebreak == -1) {
         break;
       }
-    
+
       String line = messageBuffer.substring(0, linebreak);
       line = line.trim();
       messageBuffer.delete(0, linebreak + 1);
-    
+
       try {
         double value = Double.valueOf(line);
         buffer.add(value);
-      } catch(NumberFormatException e) {
-        continue; // ignore lines that can't be cast to a number
+      } catch (NumberFormatException e) {
+        // ignore
       }
     }
 
-    SwingUtilities.invokeLater(new Runnable() {
-      public void run() {        
-        SerialPlotter.this.repaint();
-    }});
+    SwingUtilities.invokeLater(SerialPlotter.this::repaint);
   }
-  
+
   public void open() throws Exception {
     super.open();
-  
+
     if (serial != null) return;
 
     serial = new Serial(getBoardPort().getAddress(), serialRate) {

app/src/processing/app/helpers/CircularBuffer.java

@@ -3,77 +3,74 @@
 import java.util.NoSuchElementException;
 
 public class CircularBuffer {
-  private double[] elements;
+
+  private final double[] elements;
   private int start = -1;
   private int end = -1;
-  private int capacity;
-  
+  private final int capacity;
+
   public void add(double num) {
     end = (end + 1) % capacity;
     elements[end] = num;
-    if(start == end || start == -1) {
+    if (start == end || start == -1) {
       start = (start + 1) % capacity;
     }
   }
-  
+
   public double get(int index) {
-    if(index >= capacity) {
+    if (index >= capacity) {
       throw new IndexOutOfBoundsException();
     }
-    if(index >= size()) {
+    if (index >= size()) {
       throw new IndexOutOfBoundsException();
     }
-    
+
     return elements[(start + index) % capacity];
   }
-  
+
   public boolean isEmpty() {
     return start == -1 && end == -1;
   }
-  
-  public void clear() {
-    start = end = -1;
-  }
-  
+
   public CircularBuffer(int capacity) {
     this.capacity = capacity;
     elements = new double[capacity];
   }
-  
+
   public double min() {
-    if(size() == 0) {
+    if (size() == 0) {
       throw new NoSuchElementException();
     }
-    
+
     double out = get(0);
-    for(int i = 1; i < size(); ++i) {
+    for (int i = 1; i < size(); ++i) {
       out = Math.min(out, get(i));
     }
-		
+
     return out;
   }
-  
+
   public double max() {
-    if(size() == 0) {
+    if (size() == 0) {
       throw new NoSuchElementException();
     }
-    	
+
     double out = get(0);
-    for(int i = 1; i < size(); ++i) {
+    for (int i = 1; i < size(); ++i) {
       out = Math.max(out, get(i));
     }
-    
+
     return out;
   }
-  
+
   public int size() {
-    if(end == -1) {
+    if (end == -1) {
       return 0;
     }
-    
+
     return (end - start + capacity) % capacity + 1;
   }
-  
+
   public int capacity() {
     return capacity;
   }