gecko/mobile/android/base/gfx/ScrollbarLayer.java

518 lines
20 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.mozglue.DirectBufferAllocator;
import org.mozilla.gecko.util.FloatUtils;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.Rect;
import android.graphics.RectF;
import android.opengl.GLES20;
import java.nio.ByteBuffer;
import java.nio.FloatBuffer;
/**
* 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 final boolean mVertical;
private final Bitmap mBitmap;
private final Canvas mCanvas;
private float mOpacity;
// To avoid excessive GC, declare some objects here that would otherwise
// be created and destroyed frequently during draw().
private final RectF mBarRectF;
private final Rect mBarRect;
private final float[] mBodyCoords;
private final float[] mCap;
private LayerRenderer mRenderer;
private int mProgram;
private int mPositionHandle;
private int mTextureHandle;
private int mSampleHandle;
private int mTMatrixHandle;
private int mOpacityHandle;
// Fragment shader used to draw the scroll-bar with opacity
private static final String FRAGMENT_SHADER =
"precision mediump float;\n" +
"varying vec2 vTexCoord;\n" +
"uniform sampler2D sTexture;\n" +
"uniform float uOpacity;\n" +
"void main() {\n" +
" gl_FragColor = texture2D(sTexture, vTexCoord);\n" +
" gl_FragColor.a *= uOpacity;\n" +
"}\n";
// Dimensions of the texture image
private static final float TEX_HEIGHT = 8.0f;
private static final float TEX_WIDTH = 8.0f;
// Texture coordinates for the scrollbar's body
// We take a 1x1 pixel from the center of the image and scale it to become the bar
private static final float[] BODY_TEX_COORDS = {
// x, y
CAP_RADIUS/TEX_WIDTH, CAP_RADIUS/TEX_HEIGHT,
CAP_RADIUS/TEX_WIDTH, (CAP_RADIUS+1)/TEX_HEIGHT,
(CAP_RADIUS+1)/TEX_WIDTH, CAP_RADIUS/TEX_HEIGHT,
(CAP_RADIUS+1)/TEX_WIDTH, (CAP_RADIUS+1)/TEX_HEIGHT
};
// Texture coordinates for the top cap of the scrollbar
private static final float[] TOP_CAP_TEX_COORDS = {
// x, y
0 , 1.0f - CAP_RADIUS/TEX_HEIGHT,
0 , 1.0f,
BAR_SIZE/TEX_WIDTH, 1.0f - CAP_RADIUS/TEX_HEIGHT,
BAR_SIZE/TEX_WIDTH, 1.0f
};
// Texture coordinates for the bottom cap of the scrollbar
private static final float[] BOT_CAP_TEX_COORDS = {
// x, y
0 , 1.0f - BAR_SIZE/TEX_HEIGHT,
0 , 1.0f - CAP_RADIUS/TEX_HEIGHT,
BAR_SIZE/TEX_WIDTH, 1.0f - BAR_SIZE/TEX_HEIGHT,
BAR_SIZE/TEX_WIDTH, 1.0f - CAP_RADIUS/TEX_HEIGHT
};
// Texture coordinates for the left cap of the scrollbar
private static final float[] LEFT_CAP_TEX_COORDS = {
// x, y
0 , 1.0f - BAR_SIZE/TEX_HEIGHT,
0 , 1.0f,
CAP_RADIUS/TEX_WIDTH, 1.0f - BAR_SIZE/TEX_HEIGHT,
CAP_RADIUS/TEX_WIDTH, 1.0f
};
// Texture coordinates for the right cap of the scrollbar
private static final float[] RIGHT_CAP_TEX_COORDS = {
// x, y
CAP_RADIUS/TEX_WIDTH, 1.0f - BAR_SIZE/TEX_HEIGHT,
CAP_RADIUS/TEX_WIDTH, 1.0f,
BAR_SIZE/TEX_WIDTH , 1.0f - BAR_SIZE/TEX_HEIGHT,
BAR_SIZE/TEX_WIDTH , 1.0f
};
private ScrollbarLayer(LayerRenderer renderer, CairoImage image, boolean vertical, ByteBuffer buffer) {
super(image, TileLayer.PaintMode.NORMAL);
mVertical = vertical;
mRenderer = renderer;
IntSize size = image.getSize();
mBitmap = Bitmap.createBitmap(size.width, size.height, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
// Paint a spot to use as the scroll indicator
Paint foregroundPaint = new Paint();
foregroundPaint.setAntiAlias(true);
foregroundPaint.setStyle(Paint.Style.FILL);
foregroundPaint.setColor(Color.argb(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(buffer.asIntBuffer());
mBarRectF = new RectF();
mBarRect = new Rect();
mBodyCoords = new float[20];
mCap = new float[20];
}
public static ScrollbarLayer create(LayerRenderer renderer, boolean vertical) {
// just create an empty image for now, it will get drawn
// on demand anyway
int imageSize = IntSize.nextPowerOfTwo(BAR_SIZE);
ByteBuffer buffer = DirectBufferAllocator.allocate(imageSize * imageSize * 4);
CairoImage image = new BufferedCairoImage(buffer, imageSize, imageSize,
CairoImage.FORMAT_ARGB32);
return new ScrollbarLayer(renderer, image, vertical, buffer);
}
private void createProgram() {
int vertexShader = LayerRenderer.loadShader(GLES20.GL_VERTEX_SHADER,
LayerRenderer.DEFAULT_VERTEX_SHADER);
int fragmentShader = LayerRenderer.loadShader(GLES20.GL_FRAGMENT_SHADER,
FRAGMENT_SHADER);
mProgram = GLES20.glCreateProgram();
GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program
GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
GLES20.glLinkProgram(mProgram); // creates OpenGL program executables
// Get handles to the shaders' vPosition, aTexCoord, sTexture, and uTMatrix members.
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
mTextureHandle = GLES20.glGetAttribLocation(mProgram, "aTexCoord");
mSampleHandle = GLES20.glGetUniformLocation(mProgram, "sTexture");
mTMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uTMatrix");
mOpacityHandle = GLES20.glGetUniformLocation(mProgram, "uOpacity");
}
private void activateProgram() {
// Add the program to the OpenGL environment
GLES20.glUseProgram(mProgram);
// Set the transformation matrix
GLES20.glUniformMatrix4fv(mTMatrixHandle, 1, false,
LayerRenderer.DEFAULT_TEXTURE_MATRIX, 0);
// Enable the arrays from which we get the vertex and texture coordinates
GLES20.glEnableVertexAttribArray(mPositionHandle);
GLES20.glEnableVertexAttribArray(mTextureHandle);
GLES20.glUniform1i(mSampleHandle, 0);
GLES20.glUniform1f(mOpacityHandle, mOpacity);
}
private void deactivateProgram() {
GLES20.glDisableVertexAttribArray(mTextureHandle);
GLES20.glDisableVertexAttribArray(mPositionHandle);
GLES20.glUseProgram(0);
}
/**
* 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(); // called on compositor thread
mOpacity = Math.max(mOpacity - FADE_AMOUNT, 0.0f);
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(); // called on compositor thread
mOpacity = 1.0f;
endTransaction();
return true;
}
@Override
public void draw(RenderContext context) {
if (!initialized())
return;
// Create the shader program, if necessary
if (mProgram == 0) {
createProgram();
}
// Enable the shader program
mRenderer.deactivateDefaultProgram();
activateProgram();
GLES20.glEnable(GLES20.GL_BLEND);
GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);
if (mVertical) {
getVerticalRect(context, mBarRectF);
} else {
getHorizontalRect(context, mBarRectF);
}
RectUtils.round(mBarRectF, mBarRect);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, getTextureID());
float viewWidth = context.viewport.width();
float viewHeight = context.viewport.height();
float top = viewHeight - mBarRect.top;
float bot = viewHeight - mBarRect.bottom;
// Coordinates for the scrollbar's body combined with the texture coordinates
// x, y, z, texture_x, texture_y
mBodyCoords[0] = mBarRect.left/viewWidth;
mBodyCoords[1] = bot/viewHeight;
mBodyCoords[2] = 0;
mBodyCoords[3] = BODY_TEX_COORDS[0];
mBodyCoords[4] = BODY_TEX_COORDS[1];
mBodyCoords[5] = mBarRect.left/viewWidth;
mBodyCoords[6] = (bot+mBarRect.height())/viewHeight;
mBodyCoords[7] = 0;
mBodyCoords[8] = BODY_TEX_COORDS[2];
mBodyCoords[9] = BODY_TEX_COORDS[3];
mBodyCoords[10] = (mBarRect.left+mBarRect.width())/viewWidth;
mBodyCoords[11] = bot/viewHeight;
mBodyCoords[12] = 0;
mBodyCoords[13] = BODY_TEX_COORDS[4];
mBodyCoords[14] = BODY_TEX_COORDS[5];
mBodyCoords[15] = (mBarRect.left+mBarRect.width())/viewWidth;
mBodyCoords[16] = (bot+mBarRect.height())/viewHeight;
mBodyCoords[17] = 0;
mBodyCoords[18] = BODY_TEX_COORDS[6];
mBodyCoords[19] = BODY_TEX_COORDS[7];
// Get the buffer and handles from the context
FloatBuffer coordBuffer = context.coordBuffer;
int positionHandle = mPositionHandle;
int textureHandle = mTextureHandle;
// Make sure we are at position zero in the buffer in case other draw methods did not
// clean up after themselves
coordBuffer.position(0);
coordBuffer.put(mBodyCoords);
// Unbind any the current array buffer so we can use client side buffers
GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, 0);
// Vertex coordinates are x,y,z starting at position 0 into the buffer.
coordBuffer.position(0);
GLES20.glVertexAttribPointer(positionHandle, 3, GLES20.GL_FLOAT, false, 20,
coordBuffer);
// Texture coordinates are texture_x, texture_y starting at position 3 into the buffer.
coordBuffer.position(3);
GLES20.glVertexAttribPointer(textureHandle, 2, GLES20.GL_FLOAT, false, 20,
coordBuffer);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
// Reset the position in the buffer for the next set of vertex and texture coordinates.
coordBuffer.position(0);
if (mVertical) {
// top endcap
// x, y, z, texture_x, texture_y
mCap[0] = mBarRect.left/viewWidth;
mCap[1] = top/viewHeight;
mCap[2] = 0;
mCap[3] = TOP_CAP_TEX_COORDS[0];
mCap[4] = TOP_CAP_TEX_COORDS[1];
mCap[5] = mBarRect.left/viewWidth;
mCap[6] = (top+CAP_RADIUS)/viewHeight;
mCap[7] = 0;
mCap[8] = TOP_CAP_TEX_COORDS[2];
mCap[9] = TOP_CAP_TEX_COORDS[3];
mCap[10] = (mBarRect.left+BAR_SIZE)/viewWidth;
mCap[11] = top/viewHeight;
mCap[12] = 0;
mCap[13] = TOP_CAP_TEX_COORDS[4];
mCap[14] = TOP_CAP_TEX_COORDS[5];
mCap[15] = (mBarRect.left+BAR_SIZE)/viewWidth;
mCap[16] = (top+CAP_RADIUS)/viewHeight;
mCap[17] = 0;
mCap[18] = TOP_CAP_TEX_COORDS[6];
mCap[19] = TOP_CAP_TEX_COORDS[7];
coordBuffer.put(mCap);
// Vertex coordinates are x,y,z starting at position 0 into the buffer.
coordBuffer.position(0);
GLES20.glVertexAttribPointer(positionHandle, 3, GLES20.GL_FLOAT, false, 20,
coordBuffer);
// Texture coordinates are texture_x, texture_y starting at position 3 into the
// buffer.
coordBuffer.position(3);
GLES20.glVertexAttribPointer(textureHandle, 2, GLES20.GL_FLOAT, false, 20,
coordBuffer);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
// Reset the position in the buffer for the next set of vertex and texture
// coordinates.
coordBuffer.position(0);
// bottom endcap
// x, y, z, texture_x, texture_y
mCap[0] = mBarRect.left/viewWidth;
mCap[1] = (bot-CAP_RADIUS)/viewHeight;
mCap[2] = 0;
mCap[3] = BOT_CAP_TEX_COORDS[0];
mCap[4] = BOT_CAP_TEX_COORDS[1];
mCap[5] = mBarRect.left/viewWidth;
mCap[6] = (bot)/viewHeight;
mCap[7] = 0;
mCap[8] = BOT_CAP_TEX_COORDS[2];
mCap[9] = BOT_CAP_TEX_COORDS[3];
mCap[10] = (mBarRect.left+BAR_SIZE)/viewWidth;
mCap[11] = (bot-CAP_RADIUS)/viewHeight;
mCap[12] = 0;
mCap[13] = BOT_CAP_TEX_COORDS[4];
mCap[14] = BOT_CAP_TEX_COORDS[5];
mCap[15] = (mBarRect.left+BAR_SIZE)/viewWidth;
mCap[16] = (bot)/viewHeight;
mCap[17] = 0;
mCap[18] = BOT_CAP_TEX_COORDS[6];
mCap[19] = BOT_CAP_TEX_COORDS[7];
coordBuffer.put(mCap);
// Vertex coordinates are x,y,z starting at position 0 into the buffer.
coordBuffer.position(0);
GLES20.glVertexAttribPointer(positionHandle, 3, GLES20.GL_FLOAT, false, 20,
coordBuffer);
// Texture coordinates are texture_x, texture_y starting at position 3 into the
// buffer.
coordBuffer.position(3);
GLES20.glVertexAttribPointer(textureHandle, 2, GLES20.GL_FLOAT, false, 20,
coordBuffer);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
// Reset the position in the buffer for the next set of vertex and texture
// coordinates.
coordBuffer.position(0);
} else {
// left endcap
// x, y, z, texture_x, texture_y
mCap[0] = (mBarRect.left-CAP_RADIUS)/viewWidth;
mCap[1] = bot/viewHeight;
mCap[2] = 0;
mCap[3] = LEFT_CAP_TEX_COORDS[0];
mCap[4] = LEFT_CAP_TEX_COORDS[1];
mCap[5] = (mBarRect.left-CAP_RADIUS)/viewWidth;
mCap[6] = (bot+BAR_SIZE)/viewHeight;
mCap[7] = 0;
mCap[8] = LEFT_CAP_TEX_COORDS[2];
mCap[9] = LEFT_CAP_TEX_COORDS[3];
mCap[10] = (mBarRect.left)/viewWidth;
mCap[11] = bot/viewHeight;
mCap[12] = 0;
mCap[13] = LEFT_CAP_TEX_COORDS[4];
mCap[14] = LEFT_CAP_TEX_COORDS[5];
mCap[15] = (mBarRect.left)/viewWidth;
mCap[16] = (bot+BAR_SIZE)/viewHeight;
mCap[17] = 0;
mCap[18] = LEFT_CAP_TEX_COORDS[6];
mCap[19] = LEFT_CAP_TEX_COORDS[7];
coordBuffer.put(mCap);
// Vertex coordinates are x,y,z starting at position 0 into the buffer.
coordBuffer.position(0);
GLES20.glVertexAttribPointer(positionHandle, 3, GLES20.GL_FLOAT, false, 20,
coordBuffer);
// Texture coordinates are texture_x, texture_y starting at position 3 into the
// buffer.
coordBuffer.position(3);
GLES20.glVertexAttribPointer(textureHandle, 2, GLES20.GL_FLOAT, false, 20,
coordBuffer);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
// Reset the position in the buffer for the next set of vertex and texture
// coordinates.
coordBuffer.position(0);
// right endcap
// x, y, z, texture_x, texture_y
mCap[0] = mBarRect.right/viewWidth;
mCap[1] = (bot)/viewHeight;
mCap[2] = 0;
mCap[3] = RIGHT_CAP_TEX_COORDS[0];
mCap[4] = RIGHT_CAP_TEX_COORDS[1];
mCap[5] = mBarRect.right/viewWidth;
mCap[6] = (bot+BAR_SIZE)/viewHeight;
mCap[7] = 0;
mCap[8] = RIGHT_CAP_TEX_COORDS[2];
mCap[9] = RIGHT_CAP_TEX_COORDS[3];
mCap[10] = (mBarRect.right+CAP_RADIUS)/viewWidth;
mCap[11] = (bot)/viewHeight;
mCap[12] = 0;
mCap[13] = RIGHT_CAP_TEX_COORDS[4];
mCap[14] = RIGHT_CAP_TEX_COORDS[5];
mCap[15] = (mBarRect.right+CAP_RADIUS)/viewWidth;
mCap[16] = (bot+BAR_SIZE)/viewHeight;
mCap[17] = 0;
mCap[18] = RIGHT_CAP_TEX_COORDS[6];
mCap[19] = RIGHT_CAP_TEX_COORDS[7];
coordBuffer.put(mCap);
// Vertex coordinates are x,y,z starting at position 0 into the buffer.
coordBuffer.position(0);
GLES20.glVertexAttribPointer(positionHandle, 3, GLES20.GL_FLOAT, false, 20,
coordBuffer);
// Texture coordinates are texture_x, texture_y starting at position 3 into the
// buffer.
coordBuffer.position(3);
GLES20.glVertexAttribPointer(textureHandle, 2, GLES20.GL_FLOAT, false, 20,
coordBuffer);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
}
// Enable the default shader program again
deactivateProgram();
mRenderer.activateDefaultProgram();
}
private void getVerticalRect(RenderContext context, RectF dest) {
RectF viewport = context.viewport;
RectF pageRect = context.pageRect;
float barStart = ((viewport.top - pageRect.top) * (viewport.height() / pageRect.height())) + CAP_RADIUS;
float barEnd = ((viewport.bottom - pageRect.top) * (viewport.height() / pageRect.height())) - CAP_RADIUS;
if (barStart > barEnd) {
float middle = (barStart + barEnd) / 2.0f;
barStart = barEnd = middle;
}
float right = viewport.width() - PADDING;
dest.set(right - BAR_SIZE, barStart, right, barEnd);
}
private void getHorizontalRect(RenderContext context, RectF dest) {
RectF viewport = context.viewport;
RectF pageRect = context.pageRect;
float barStart = ((viewport.left - pageRect.left) * (viewport.width() / pageRect.width())) + CAP_RADIUS;
float barEnd = ((viewport.right - pageRect.left) * (viewport.width() / pageRect.width())) - CAP_RADIUS;
if (barStart > barEnd) {
float middle = (barStart + barEnd) / 2.0f;
barStart = barEnd = middle;
}
float bottom = viewport.height() - PADDING;
dest.set(barStart, bottom - BAR_SIZE, barEnd, bottom);
}
}