michael@0: /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko.gfx;
michael@0: 
michael@0: import org.mozilla.gecko.mozglue.DirectBufferAllocator;
michael@0: 
michael@0: import android.graphics.Bitmap;
michael@0: import android.graphics.Canvas;
michael@0: import android.graphics.Color;
michael@0: import android.graphics.Paint;
michael@0: import android.graphics.Typeface;
michael@0: 
michael@0: import java.nio.ByteBuffer;
michael@0: 
michael@0: /**
michael@0:  * Draws text on a layer. This is used for the frame rate meter.
michael@0:  */
michael@0: public class TextLayer extends SingleTileLayer {
michael@0:     private final ByteBuffer mBuffer;   // this buffer is owned by the BufferedCairoImage
michael@0:     private final IntSize mSize;
michael@0: 
michael@0:     /*
michael@0:      * This awkward pattern is necessary due to Java's restrictions on when one can call superclass
michael@0:      * constructors.
michael@0:      */
michael@0:     private TextLayer(ByteBuffer buffer, BufferedCairoImage image, IntSize size, String text) {
michael@0:         super(false, image);
michael@0:         mBuffer = buffer;
michael@0:         mSize = size;
michael@0:         renderText(text);
michael@0:     }
michael@0: 
michael@0:     public static TextLayer create(IntSize size, String text) {
michael@0:         ByteBuffer buffer = DirectBufferAllocator.allocate(size.width * size.height * 4);
michael@0:         BufferedCairoImage image = new BufferedCairoImage(buffer, size.width, size.height,
michael@0:                                                           CairoImage.FORMAT_ARGB32);
michael@0:         return new TextLayer(buffer, image, size, text);
michael@0:     }
michael@0: 
michael@0:     public void setText(String text) {
michael@0:         renderText(text);
michael@0:         invalidate();
michael@0:     }
michael@0: 
michael@0:     private void renderText(String text) {
michael@0:         Bitmap bitmap = Bitmap.createBitmap(mSize.width, mSize.height, Bitmap.Config.ARGB_8888);
michael@0:         Canvas canvas = new Canvas(bitmap);
michael@0: 
michael@0:         Paint textPaint = new Paint();
michael@0:         textPaint.setAntiAlias(true);
michael@0:         textPaint.setColor(Color.WHITE);
michael@0:         textPaint.setFakeBoldText(true);
michael@0:         textPaint.setTextSize(18.0f);
michael@0:         textPaint.setTypeface(Typeface.DEFAULT_BOLD);
michael@0:         float width = textPaint.measureText(text) + 18.0f;
michael@0: 
michael@0:         Paint backgroundPaint = new Paint();
michael@0:         backgroundPaint.setColor(Color.argb(127, 0, 0, 0));
michael@0:         canvas.drawRect(0.0f, 0.0f, width, 18.0f + 6.0f, backgroundPaint);
michael@0: 
michael@0:         canvas.drawText(text, 6.0f, 18.0f, textPaint);
michael@0: 
michael@0:         bitmap.copyPixelsToBuffer(mBuffer.asIntBuffer());
michael@0:     }
michael@0: }
michael@0: