gecko/mobile/android/base/gfx/TextLayer.java
2012-05-21 12:12:37 +01:00

74 lines
2.6 KiB
Java

/* -*- 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.GeckoAppShell;
import org.mozilla.gecko.gfx.BufferedCairoImage;
import org.mozilla.gecko.gfx.CairoImage;
import org.mozilla.gecko.gfx.IntSize;
import org.mozilla.gecko.gfx.SingleTileLayer;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Typeface;
import android.util.Log;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;
/**
* 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 = GeckoAppShell.allocateDirectBuffer(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());
}
}