How to put text in a drawable?

Question

I'm trying to create a drawable on the fly to use as a background for a custom linearlayout. It needs to have hash marks and such (no big deal), but also have numbers labeling what the hash marks are (like a ruler). I know I can just create text elements and put them inside the linearlayout and just have the hash marks in the drawable, but I'm hoping to have them inside the drawable as well, so I don't have to do measurement calculations twice.

Answer 1

I've read the book "Professional Android 2 Application Development" (by Reto Meier). Amongst others, it contains an example project where you create a simple compass application where you "draw" text, markers etc.

The brief explanation is that you create a class that extends the android.view.View class and overrides the onDraw(Canvas) method.

All the source code form the book is available for download here: http://www.wrox.com/WileyCDA/WroxTitle/Professional-Android-2-Application-Development.productCd-0470565527,descCd-DOWNLOAD.html. If you download the code and look inside the project named "Chapter 4 Compass", I believe you would find what you're looking for :)

Answer 2

Here is a brief example of a TextDrawable which works like a normal drawable but lets you specify text as the only constructor variable:

public class TextDrawable extends Drawable {      private final String text;     private final Paint paint;      public TextDrawable(String text) {          this.text = text;          this.paint = new Paint();         paint.setColor(Color.WHITE);         paint.setTextSize(22f);         paint.setAntiAlias(true);         paint.setFakeBoldText(true);         paint.setShadowLayer(6f, 0, 0, Color.BLACK);         paint.setStyle(Paint.Style.FILL);         paint.setTextAlign(Paint.Align.LEFT);     }      @Override     public void draw(Canvas canvas) {         canvas.drawText(text, 0, 0, paint);     }      @Override     public void setAlpha(int alpha) {         paint.setAlpha(alpha);     }      @Override     public void setColorFilter(ColorFilter cf) {         paint.setColorFilter(cf);     }      @Override     public int getOpacity() {         return PixelFormat.TRANSLUCENT;     } }