The Tor Browser / file revision

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-

  * This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 package org.mozilla.gecko.gfx;

 import org.mozilla.gecko.mozglue.DirectBufferAllocator;

 import android.graphics.Bitmap;

 import android.graphics.Canvas;

 import android.graphics.Color;

 import android.graphics.Paint;

 import android.graphics.Typeface;

 import java.nio.ByteBuffer;

 /**

  * Draws text on a layer. This is used for the frame rate meter.

  */

 public class TextLayer extends SingleTileLayer {

     private final ByteBuffer mBuffer;   // this buffer is owned by the BufferedCairoImage

     private final IntSize mSize;

     /*

      * This awkward pattern is necessary due to Java's restrictions on when one can call superclass

      * constructors.

      */

     private TextLayer(ByteBuffer buffer, BufferedCairoImage image, IntSize size, String text) {

         super(false, image);

         mBuffer = buffer;

         mSize = size;

         renderText(text);

     }

     public static TextLayer create(IntSize size, String text) {

         ByteBuffer buffer = DirectBufferAllocator.allocate(size.width * size.height * 4);

         BufferedCairoImage image = new BufferedCairoImage(buffer, size.width, size.height,

                                                           CairoImage.FORMAT_ARGB32);

         return new TextLayer(buffer, image, size, text);

     }

     public void setText(String text) {

         renderText(text);

         invalidate();

     }

     private void renderText(String text) {

         Bitmap bitmap = Bitmap.createBitmap(mSize.width, mSize.height, Bitmap.Config.ARGB_8888);

         Canvas canvas = new Canvas(bitmap);

         Paint textPaint = new Paint();

         textPaint.setAntiAlias(true);

         textPaint.setColor(Color.WHITE);

         textPaint.setFakeBoldText(true);

         textPaint.setTextSize(18.0f);

         textPaint.setTypeface(Typeface.DEFAULT_BOLD);

         float width = textPaint.measureText(text) + 18.0f;

         Paint backgroundPaint = new Paint();

         backgroundPaint.setColor(Color.argb(127, 0, 0, 0));

         canvas.drawRect(0.0f, 0.0f, width, 18.0f + 6.0f, backgroundPaint);

         canvas.drawText(text, 6.0f, 18.0f, textPaint);

         bitmap.copyPixelsToBuffer(mBuffer.asIntBuffer());

     }

 }