Text editor using text layout

Question

Does anyone know where I can find code that uses TextLayout to create a text editor directly?

Answer 1

Are you sure you wouldn't be better off using a JTextArea? You can set the font to whatever you want, and make the background transparent, and then use its paint() method to paint it on any other Graphics object?
But if you still insist on using TextLayouts, here's a method to generate some.
     String text = "I have a lot of text here that can change with time.\nNote it handles multiple lines";
     public static final char separator = (char)Character.LINE_SEPARATOR;
     Rectangle onScreen = ... ;
     public TextLayout[] getLayouts(Graphics2D g) {
          return getLayouts(g.getFontRenderContext());
     //a temporary list of lines that the text has to broken into. (Each element is a separate line)
     transient Vector v = new Vector();
     /* Anytime another method changes the text, or the attributes of the text, you'll
     * want to set cachedLayouts to null. Otherwise they will automatically be
     * returned whenever you ask for the TextLayout[]'s... makes this MUCH more efficient.
     transient TextLayout[] cachedLayouts = null;
     static transient TextLayout[] emptyLayout = null;
     protected TextLayout[] getLayouts(FontRenderContext frc) {
          if(frc==null) return new TextLayout[0]; //or you might want to throw an exception
          if(text.length()==0) {
               if(emptyLayout==null) {
                    emptyLayout = new TextLayout[1];
                    emptyLayout[0] = new TextLayout((new AttributedString(" ")).getIterator(),frc);
               return emptyLayout;
          if(cachedLayouts!=null) return cachedLayouts;
          String temp = text;
          v.clear();
          //first break up the text into lines based on how many times the line separator char appears
          while(temp.length()>0) {
               if(temp.indexOf(separator)!=-1) {
                    v.add(temp.substring(0,temp.indexOf(separator))+" ");
                    temp = temp.substring(temp.indexOf(separator)+1);
               } else {
                    v.add(temp);
                    temp = "";
          String[] lines = new String[v.size()];
          lines = (String[])v.toArray(lines);
          v.clear();
          int handledText = 0;
          AttributedCharacterIterator aci;
          for(int z = 0; z<lines.length; z++) {
               aci = new AttributedString( lines[z].substring(handledText) ).getIterator();
               LineBreakMeasurer lbm = new LineBreakMeasurer(aci, frc);
               lbm.setPosition(0);
               while (lbm.getPosition() < lines[z].length()) {
                    v.add( lbm.nextLayout(Math.max(onScreen.width-8,0)) );
               handledText+=lines[z].length();
          TextLayout[] t = new TextLayout[v.size()];
          cachedLayouts = (TextLayout[])v.toArray(t);
          return cachedLayouts;
This just gets you layouts. if you actually want to the user to edit those (with cursor and selected text et al) then you have your work cut out for you.