Display line numbers for the file being edited

app/src/processing/app/syntax/JEditTextArea.java

@@ -87,6 +87,7 @@ public class JEditTextArea extends JComponent
 
     // Initialize some misc. stuff
     painter = new TextAreaPainter(this,defaults);
+    editorLineNumbers = new TextAreaLineNumbers(defaults.font, defaults.bgcolor, defaults.fgcolor, (int) painter.getPreferredSize().getHeight());
     documentHandler = new DocumentHandler();
     eventListenerList = new EventListenerList();
     caretEvent = new MutableCaretEvent();
@@ -96,6 +97,7 @@ public class JEditTextArea extends JComponent
 
     // Initialize the GUI
     setLayout(new ScrollLayout());
+    add(LEFT, editorLineNumbers);
     add(CENTER, painter);
     add(RIGHT, vertical = new JScrollBar(JScrollBar.VERTICAL));
     add(BOTTOM, horizontal = new JScrollBar(JScrollBar.HORIZONTAL));
@@ -315,6 +317,12 @@ public class JEditTextArea extends JComponent
       horizontal.setUnitIncrement(charWidth);
       horizontal.setBlockIncrement(width / 2);
     }
+    updateLineNumbers();
+  }
+
+  private void updateLineNumbers() {
+    editorLineNumbers.updateLineNumbers(getFirstLine() + 1, Math.min(getFirstLine() + getVisibleLines() + 1, getLineCount()));
+    editorLineNumbers.updateWidthForNumDigits(String.valueOf(getLineCount()).length());
   }
 
   /**
@@ -335,7 +343,7 @@ public class JEditTextArea extends JComponent
     if (firstLine != vertical.getValue()) {
       updateScrollBars();
     }
-    painter.repaint();
+    repaintEditor();
   }
 
   /**
@@ -377,7 +385,7 @@ public class JEditTextArea extends JComponent
     this.horizontalOffset = horizontalOffset;
     if(horizontalOffset != horizontal.getValue())
       updateScrollBars();
-    painter.repaint();
+    repaintEditor();
   }
 
   /**
@@ -407,12 +415,17 @@ public class JEditTextArea extends JComponent
     if(changed)
       {
         updateScrollBars();
-        painter.repaint();
+        repaintEditor();
       }
 
     return changed;
   }
 
+  private void repaintEditor() {
+    painter.repaint();
+    updateLineNumbers();
+  }
+  
   /**
    * Ensures that the caret is visible by scrolling the text area if
    * necessary.
@@ -732,7 +745,7 @@ public class JEditTextArea extends JComponent
 
     select(0, 0);
     updateScrollBars();
-    painter.repaint();
+    repaintEditor();
   }
 
 
@@ -753,7 +766,7 @@ public class JEditTextArea extends JComponent
     select(start, stop);
     updateScrollBars();
     setScrollPosition(scroll);
-    painter.repaint();
+    repaintEditor();
   }
 
 
@@ -1747,6 +1760,7 @@ public class JEditTextArea extends JComponent
   }
 
   // protected members
+  protected static String LEFT = "left";
   protected static String CENTER = "center";
   protected static String RIGHT = "right";
   protected static String BOTTOM = "bottom";
@@ -1755,6 +1769,7 @@ public class JEditTextArea extends JComponent
   protected static Timer caretTimer;
 
   protected TextAreaPainter painter;
+  protected TextAreaLineNumbers editorLineNumbers;
 
   //protected EditPopupMenu popup;
   protected JPopupMenu popup;
@@ -1881,7 +1896,9 @@ public class JEditTextArea extends JComponent
 
     public void addLayoutComponent(String name, Component comp)
     {
-      if(name.equals(CENTER))
+      if(name.equals(LEFT))
+        left = comp;
+      else if(name.equals(CENTER))
         center = comp;
       else if(name.equals(RIGHT))
         right = comp;
@@ -1893,6 +1910,8 @@ public class JEditTextArea extends JComponent
 
     public void removeLayoutComponent(Component comp)
     {
+      if(left == comp)
+        left = null;
       if(center == comp)
         center = null;
       if(right == comp)
@@ -1913,6 +1932,8 @@ public class JEditTextArea extends JComponent
       Dimension centerPref = center.getPreferredSize();
       dim.width += centerPref.width;
       dim.height += centerPref.height;
+      Dimension leftPref = left.getPreferredSize();
+      dim.width += leftPref.width;
       Dimension rightPref = right.getPreferredSize();
       dim.width += rightPref.width;
       Dimension bottomPref = bottom.getPreferredSize();
@@ -1931,6 +1952,8 @@ public class JEditTextArea extends JComponent
       Dimension centerPref = center.getMinimumSize();
       dim.width += centerPref.width;
       dim.height += centerPref.height;
+      Dimension leftPref = left.getMinimumSize();
+      dim.width += leftPref.width;
       Dimension rightPref = right.getMinimumSize();
       dim.width += rightPref.width;
       Dimension bottomPref = bottom.getMinimumSize();
@@ -1950,11 +1973,19 @@ public class JEditTextArea extends JComponent
       int ibottom = insets.bottom;
       int iright = insets.right;
 
+      int leftWidth = left.getSize().width;
       int rightWidth = right.getPreferredSize().width;
       int bottomHeight = bottom.getPreferredSize().height;
-      int centerWidth = size.width - rightWidth - ileft - iright;
+      int centerWidth = size.width - leftWidth - rightWidth - ileft - iright;
       int centerHeight = size.height - bottomHeight - itop - ibottom;
 
+      left.setBounds(ileft,
+                      itop,
+                      leftWidth,
+                      centerHeight);
+      
+      ileft += leftWidth;
+      
       center.setBounds(ileft, // + LEFT_EXTRA,
                        itop,
                        centerWidth, // - LEFT_EXTRA,
@@ -1984,6 +2015,7 @@ public class JEditTextArea extends JComponent
     }
 
     // private members
+    private Component left;
     private Component center;
     private Component right;
     private Component bottom;

app/src/processing/app/syntax/TextAreaLineNumbers.java

@@ -0,0 +1,85 @@
+/*
+ * TextAreaLineNumbers.java - Show line numbers for the open file in the editor
+ * Copyright (C) 2013 Cayci Gorlitsky
+ *
+ * You may use and modify this package for any purpose. Redistribution is
+ * permitted, in both source and binary form, provided that this notice
+ * remains intact in all source distributions of this package.
+ */
+
+package processing.app.syntax;
+
+import java.awt.Color;
+import java.awt.Dimension;
+import java.awt.Font;
+import java.awt.Rectangle;
+
+import javax.swing.JTextPane;
+import javax.swing.border.MatteBorder;
+import javax.swing.text.SimpleAttributeSet;
+import javax.swing.text.StyleConstants;
+
+public class TextAreaLineNumbers extends JTextPane {
+  
+  private final int LEFT_INDENT = 6;
+  private final int RIGHT_INDENT = 6;
+  private final int RIGHT_BORDER_WIDTH = 1;
+  private final int PADDING_WIDTH = LEFT_INDENT + RIGHT_INDENT + RIGHT_BORDER_WIDTH;
+  
+  private final int MIN_WIDTH;
+  private final int DIGIT_WIDTH;
+  private final int MIN_NUM_DIGITS = 2;
+  
+  private int currStartNum = 0;
+  private int currEndNum = 0;
+  private int currNumDigits = MIN_NUM_DIGITS;
+  
+  public TextAreaLineNumbers(Font font, Color bgcolor, Color fgcolor, int preferredHeight) {
+    setFont(font);
+    setBackground(bgcolor);
+    setForeground(fgcolor);
+    setOpaque(true);
+    setEditable(false);
+    setEnabled(false);
+    setBorder(new MatteBorder(0, 0, 0, 1, new Color(240, 240, 240)));
+
+    SimpleAttributeSet attribs = new SimpleAttributeSet();  
+    StyleConstants.setAlignment(attribs , StyleConstants.ALIGN_RIGHT);
+    StyleConstants.setLeftIndent(attribs , 6);
+    StyleConstants.setRightIndent(attribs , 6);  
+    setParagraphAttributes(attribs,true); 
+    
+    DIGIT_WIDTH = getFontMetrics(getFont()).stringWidth("0");
+    MIN_WIDTH = DIGIT_WIDTH * MIN_NUM_DIGITS + PADDING_WIDTH;
+    
+    setPreferredSize(new Dimension(MIN_WIDTH, preferredHeight));
+  }
+  
+  public void updateLineNumbers(int startNum, int endNum) {
+    if (currStartNum == startNum && currEndNum == endNum) {
+      return;
+    }
+    currStartNum = startNum;
+    currEndNum = endNum;
+    
+    StringBuilder sb = new StringBuilder();
+    for (int i = startNum; i < endNum; i++) {
+      sb.append(i).append("\n");
+    }
+    sb.append(endNum);
+    setText(sb.toString());
+    
+    invalidate();
+  }
+  
+  public void updateWidthForNumDigits(int numDigits) {
+    if (currNumDigits == numDigits) {
+      return;
+    }
+    currNumDigits = numDigits;
+    
+    setBounds(new Rectangle(Math.max(MIN_WIDTH, DIGIT_WIDTH * numDigits + PADDING_WIDTH), getHeight()));
+    invalidate();
+  }
+  
+}