diff -r 000000000000 -r 6474c204b198 mobile/android/base/gfx/TextLayer.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mobile/android/base/gfx/TextLayer.java Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,69 @@ +/* -*- 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()); + } +} +