gecko/mobile/android/base/gfx/ScrollbarLayer.java
Kartikaya Gupta d84f168de3 Bug 709560 - Set blend function when enabling gl blending. r=pcwalton
The missing blend function was causing the default of GL_ONE,
GL_ZERO to take effect, making it look like alpha blending wasn't
working. It would start working once the 9-patch shadow was rendered
since that code sets the correct blend function. Fix this by
ensuring we set the blend function wherever we use blending.
2011-12-19 17:40:01 -05:00

228 lines
9.3 KiB
Java

/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Android code.
*
* The Initial Developer of the Original Code is Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2011
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Kartikaya Gupta <kgupta@mozilla.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
package org.mozilla.gecko.gfx;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PointF;
import android.graphics.PorterDuff;
import android.graphics.Rect;
import android.graphics.RectF;
import android.opengl.GLES11;
import android.opengl.GLES11Ext;
import android.util.Log;
import java.nio.ByteBuffer;
import javax.microedition.khronos.opengles.GL10;
import org.mozilla.gecko.FloatUtils;
import org.mozilla.gecko.GeckoAppShell;
/**
* Draws a small rect. This is scaled to become a scrollbar.
*/
public class ScrollbarLayer extends TileLayer {
public static final long FADE_DELAY = 500; // milliseconds before fade-out starts
private static final float FADE_AMOUNT = 0.03f; // how much (as a percent) the scrollbar should fade per frame
private static final int PADDING = 1; // gap between scrollbar and edge of viewport
private static final int BAR_SIZE = 6;
private static final int CAP_RADIUS = (BAR_SIZE / 2);
private static final int[] CROPRECT_MIDPIXEL = new int[] { CAP_RADIUS, CAP_RADIUS, 1, 1 };
private static final int[] CROPRECT_TOPCAP = new int[] { 0, CAP_RADIUS, BAR_SIZE, -CAP_RADIUS };
private static final int[] CROPRECT_BOTTOMCAP = new int[] { 0, BAR_SIZE, BAR_SIZE, -CAP_RADIUS };
private static final int[] CROPRECT_LEFTCAP = new int[] { 0, BAR_SIZE, CAP_RADIUS, -BAR_SIZE };
private static final int[] CROPRECT_RIGHTCAP = new int[] { CAP_RADIUS, BAR_SIZE, CAP_RADIUS, -BAR_SIZE };
private final boolean mVertical;
private final ByteBuffer mBuffer;
private final Bitmap mBitmap;
private final Canvas mCanvas;
private float mOpacity;
private boolean mFinalized = false;
private ScrollbarLayer(CairoImage image, boolean vertical, ByteBuffer buffer) {
super(false, image);
mVertical = vertical;
mBuffer = buffer;
IntSize size = image.getSize();
mBitmap = Bitmap.createBitmap(size.width, size.height, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
protected void finalize() throws Throwable {
try {
if (!mFinalized && mBuffer != null)
GeckoAppShell.freeDirectBuffer(mBuffer);
mFinalized = true;
} finally {
super.finalize();
}
}
public static ScrollbarLayer create(boolean vertical) {
// just create an empty image for now, it will get drawn
// on demand anyway
int imageSize = IntSize.nextPowerOfTwo(BAR_SIZE);
ByteBuffer buffer = GeckoAppShell.allocateDirectBuffer(imageSize * imageSize * 4);
CairoImage image = new BufferedCairoImage(buffer, imageSize, imageSize, CairoImage.FORMAT_ARGB32);
return new ScrollbarLayer(image, vertical, buffer);
}
/**
* Decrease the opacity of the scrollbar by one frame's worth.
* Return true if the opacity was decreased, or false if the scrollbars
* are already fully faded out.
*/
public boolean fade() {
if (FloatUtils.fuzzyEquals(mOpacity, 0.0f)) {
return false;
}
beginTransaction();
try {
setOpacity(Math.max(mOpacity - FADE_AMOUNT, 0.0f));
invalidate();
} finally {
endTransaction();
}
return true;
}
/**
* Restore the opacity of the scrollbar to fully opaque.
* Return true if the opacity was changed, or false if the scrollbars
* are already fully opaque.
*/
public boolean unfade() {
if (FloatUtils.fuzzyEquals(mOpacity, 1.0f)) {
return false;
}
beginTransaction();
try {
setOpacity(1.0f);
invalidate();
} finally {
endTransaction();
}
return true;
}
private void setOpacity(float opacity) {
mOpacity = opacity;
Paint foregroundPaint = new Paint();
foregroundPaint.setAntiAlias(true);
foregroundPaint.setStyle(Paint.Style.FILL);
// use a (a,r,g,b) color of (127,0,0,0), and multiply the alpha by mOpacity for fading
foregroundPaint.setColor(Color.argb((int)Math.round(mOpacity * 127), 0, 0, 0));
mCanvas.drawColor(Color.argb(0, 0, 0, 0), PorterDuff.Mode.CLEAR);
mCanvas.drawCircle(CAP_RADIUS, CAP_RADIUS, CAP_RADIUS, foregroundPaint);
mBitmap.copyPixelsToBuffer(mBuffer.asIntBuffer());
}
@Override
public void draw(RenderContext context) {
if (!initialized())
return;
try {
GLES11.glEnable(GL10.GL_BLEND);
GLES11.glBlendFunc(GL10.GL_SRC_ALPHA, GL10.GL_ONE_MINUS_SRC_ALPHA);
Rect rect = RectUtils.round(mVertical ? getVerticalRect(context) : getHorizontalRect(context));
GLES11.glBindTexture(GL10.GL_TEXTURE_2D, getTextureID());
float viewHeight = context.viewport.height();
// for the body of the scrollbar, we take a 1x1 pixel from the center of the image
// and scale it to become the bar
GLES11.glTexParameteriv(GL10.GL_TEXTURE_2D, GLES11Ext.GL_TEXTURE_CROP_RECT_OES, CROPRECT_MIDPIXEL, 0);
GLES11Ext.glDrawTexfOES(rect.left, viewHeight - rect.bottom, 0.0f, rect.width(), rect.height());
if (mVertical) {
// top endcap
GLES11.glTexParameteriv(GL10.GL_TEXTURE_2D, GLES11Ext.GL_TEXTURE_CROP_RECT_OES, CROPRECT_TOPCAP, 0);
GLES11Ext.glDrawTexfOES(rect.left, viewHeight - rect.top, 0.0f, BAR_SIZE, CAP_RADIUS);
// bottom endcap
GLES11.glTexParameteriv(GL10.GL_TEXTURE_2D, GLES11Ext.GL_TEXTURE_CROP_RECT_OES, CROPRECT_BOTTOMCAP, 0);
GLES11Ext.glDrawTexfOES(rect.left, viewHeight - (rect.bottom + CAP_RADIUS), 0.0f, BAR_SIZE, CAP_RADIUS);
} else {
// left endcap
GLES11.glTexParameteriv(GL10.GL_TEXTURE_2D, GLES11Ext.GL_TEXTURE_CROP_RECT_OES, CROPRECT_LEFTCAP, 0);
GLES11Ext.glDrawTexfOES(rect.left - CAP_RADIUS, viewHeight - rect.bottom, 0.0f, CAP_RADIUS, BAR_SIZE);
// right endcap
GLES11.glTexParameteriv(GL10.GL_TEXTURE_2D, GLES11Ext.GL_TEXTURE_CROP_RECT_OES, CROPRECT_RIGHTCAP, 0);
GLES11Ext.glDrawTexfOES(rect.right, viewHeight - rect.bottom, 0.0f, CAP_RADIUS, BAR_SIZE);
}
} finally {
GLES11.glDisable(GL10.GL_BLEND);
}
}
private RectF getVerticalRect(RenderContext context) {
RectF viewport = context.viewport;
FloatSize pageSize = context.pageSize;
float barStart = (viewport.height() * viewport.top / pageSize.height) + CAP_RADIUS;
float barEnd = (viewport.height() * viewport.bottom / pageSize.height) - CAP_RADIUS;
if (barStart > barEnd) {
float middle = (barStart + barEnd) / 2.0f;
barStart = barEnd = middle;
}
float right = viewport.width() - PADDING;
return new RectF(right - BAR_SIZE, barStart, right, barEnd);
}
private RectF getHorizontalRect(RenderContext context) {
RectF viewport = context.viewport;
FloatSize pageSize = context.pageSize;
float barStart = (viewport.width() * viewport.left / pageSize.width) + CAP_RADIUS;
float barEnd = (viewport.width() * viewport.right / pageSize.width) - CAP_RADIUS;
if (barStart > barEnd) {
float middle = (barStart + barEnd) / 2.0f;
barStart = barEnd = middle;
}
float bottom = viewport.height() - PADDING;
return new RectF(barStart, bottom - BAR_SIZE, barEnd, bottom);
}
}