1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/mobile/android/base/gfx/ScrollbarLayer.java Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,297 @@
1.4 +/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
1.5 + * This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +package org.mozilla.gecko.gfx;
1.10 +
1.11 +import org.mozilla.gecko.util.FloatUtils;
1.12 +
1.13 +import android.graphics.Bitmap;
1.14 +import android.graphics.Rect;
1.15 +import android.graphics.RectF;
1.16 +import android.opengl.GLES20;
1.17 +
1.18 +import java.nio.FloatBuffer;
1.19 +
1.20 +public class ScrollbarLayer extends TileLayer {
1.21 + public static final long FADE_DELAY = 500; // milliseconds before fade-out starts
1.22 + private static final float FADE_AMOUNT = 0.03f; // how much (as a percent) the scrollbar should fade per frame
1.23 +
1.24 + private final boolean mVertical;
1.25 + private float mOpacity;
1.26 +
1.27 + // To avoid excessive GC, declare some objects here that would otherwise
1.28 + // be created and destroyed frequently during draw().
1.29 + private final RectF mBarRectF;
1.30 + private final Rect mBarRect;
1.31 + private final float[] mCoords;
1.32 + private final RectF mCapRectF;
1.33 +
1.34 + private LayerRenderer mRenderer;
1.35 + private int mProgram;
1.36 + private int mPositionHandle;
1.37 + private int mTextureHandle;
1.38 + private int mSampleHandle;
1.39 + private int mTMatrixHandle;
1.40 + private int mOpacityHandle;
1.41 +
1.42 + // Fragment shader used to draw the scroll-bar with opacity
1.43 + private static final String FRAGMENT_SHADER =
1.44 + "precision mediump float;\n" +
1.45 + "varying vec2 vTexCoord;\n" +
1.46 + "uniform sampler2D sTexture;\n" +
1.47 + "uniform float uOpacity;\n" +
1.48 + "void main() {\n" +
1.49 + " gl_FragColor = texture2D(sTexture, vTexCoord);\n" +
1.50 + " gl_FragColor.a *= uOpacity;\n" +
1.51 + "}\n";
1.52 +
1.53 + // Dimensions of the texture bitmap (will always be power-of-two)
1.54 + private final int mTexWidth;
1.55 + private final int mTexHeight;
1.56 + // Some useful dimensions of the actual content in the bitmap
1.57 + private final int mBarWidth;
1.58 + private final int mCapLength;
1.59 +
1.60 + private final Rect mStartCapTexCoords; // top/left endcap coordinates
1.61 + private final Rect mBodyTexCoords; // 1-pixel slice of the texture to be stretched
1.62 + private final Rect mEndCapTexCoords; // bottom/right endcap coordinates
1.63 +
1.64 + ScrollbarLayer(LayerRenderer renderer, Bitmap scrollbarImage, IntSize imageSize, boolean vertical) {
1.65 + super(new BufferedCairoImage(scrollbarImage), TileLayer.PaintMode.NORMAL);
1.66 + mRenderer = renderer;
1.67 + mVertical = vertical;
1.68 +
1.69 + mBarRectF = new RectF();
1.70 + mBarRect = new Rect();
1.71 + mCoords = new float[20];
1.72 + mCapRectF = new RectF();
1.73 +
1.74 + mTexHeight = scrollbarImage.getHeight();
1.75 + mTexWidth = scrollbarImage.getWidth();
1.76 +
1.77 + if (mVertical) {
1.78 + mBarWidth = imageSize.width;
1.79 + mCapLength = imageSize.height / 2;
1.80 + mStartCapTexCoords = new Rect(0, mTexHeight - mCapLength, imageSize.width, mTexHeight);
1.81 + mBodyTexCoords = new Rect(0, mTexHeight - (mCapLength + 1), imageSize.width, mTexHeight - mCapLength);
1.82 + mEndCapTexCoords = new Rect(0, mTexHeight - imageSize.height, imageSize.width, mTexHeight - (mCapLength + 1));
1.83 + } else {
1.84 + mBarWidth = imageSize.height;
1.85 + mCapLength = imageSize.width / 2;
1.86 + mStartCapTexCoords = new Rect(0, mTexHeight - imageSize.height, mCapLength, mTexHeight);
1.87 + mBodyTexCoords = new Rect(mCapLength, mTexHeight - imageSize.height, mCapLength + 1, mTexHeight);
1.88 + mEndCapTexCoords = new Rect(mCapLength + 1, mTexHeight - imageSize.height, imageSize.width, mTexHeight);
1.89 + }
1.90 + }
1.91 +
1.92 + private void createProgram() {
1.93 + int vertexShader = LayerRenderer.loadShader(GLES20.GL_VERTEX_SHADER,
1.94 + LayerRenderer.DEFAULT_VERTEX_SHADER);
1.95 + int fragmentShader = LayerRenderer.loadShader(GLES20.GL_FRAGMENT_SHADER,
1.96 + FRAGMENT_SHADER);
1.97 +
1.98 + mProgram = GLES20.glCreateProgram();
1.99 + GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader to program
1.100 + GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
1.101 + GLES20.glLinkProgram(mProgram); // creates OpenGL program executables
1.102 +
1.103 + // Get handles to the shaders' vPosition, aTexCoord, sTexture, and uTMatrix members.
1.104 + mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
1.105 + mTextureHandle = GLES20.glGetAttribLocation(mProgram, "aTexCoord");
1.106 + mSampleHandle = GLES20.glGetUniformLocation(mProgram, "sTexture");
1.107 + mTMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uTMatrix");
1.108 + mOpacityHandle = GLES20.glGetUniformLocation(mProgram, "uOpacity");
1.109 + }
1.110 +
1.111 + private void activateProgram() {
1.112 + // Add the program to the OpenGL environment
1.113 + GLES20.glUseProgram(mProgram);
1.114 +
1.115 + // Set the transformation matrix
1.116 + GLES20.glUniformMatrix4fv(mTMatrixHandle, 1, false,
1.117 + LayerRenderer.DEFAULT_TEXTURE_MATRIX, 0);
1.118 +
1.119 + // Enable the arrays from which we get the vertex and texture coordinates
1.120 + GLES20.glEnableVertexAttribArray(mPositionHandle);
1.121 + GLES20.glEnableVertexAttribArray(mTextureHandle);
1.122 +
1.123 + GLES20.glUniform1i(mSampleHandle, 0);
1.124 + GLES20.glUniform1f(mOpacityHandle, mOpacity);
1.125 + }
1.126 +
1.127 + private void deactivateProgram() {
1.128 + GLES20.glDisableVertexAttribArray(mTextureHandle);
1.129 + GLES20.glDisableVertexAttribArray(mPositionHandle);
1.130 + GLES20.glUseProgram(0);
1.131 + }
1.132 +
1.133 + /**
1.134 + * Decrease the opacity of the scrollbar by one frame's worth.
1.135 + * Return true if the opacity was decreased, or false if the scrollbars
1.136 + * are already fully faded out.
1.137 + */
1.138 + public boolean fade() {
1.139 + if (FloatUtils.fuzzyEquals(mOpacity, 0.0f)) {
1.140 + return false;
1.141 + }
1.142 + beginTransaction(); // called on compositor thread
1.143 + mOpacity = Math.max(mOpacity - FADE_AMOUNT, 0.0f);
1.144 + endTransaction();
1.145 + return true;
1.146 + }
1.147 +
1.148 + /**
1.149 + * Restore the opacity of the scrollbar to fully opaque.
1.150 + * Return true if the opacity was changed, or false if the scrollbars
1.151 + * are already fully opaque.
1.152 + */
1.153 + public boolean unfade() {
1.154 + if (FloatUtils.fuzzyEquals(mOpacity, 1.0f)) {
1.155 + return false;
1.156 + }
1.157 + beginTransaction(); // called on compositor thread
1.158 + mOpacity = 1.0f;
1.159 + endTransaction();
1.160 + return true;
1.161 + }
1.162 +
1.163 + @Override
1.164 + public void draw(RenderContext context) {
1.165 + if (!initialized())
1.166 + return;
1.167 +
1.168 + // Create the shader program, if necessary
1.169 + if (mProgram == 0) {
1.170 + createProgram();
1.171 + }
1.172 +
1.173 + // Enable the shader program
1.174 + mRenderer.deactivateDefaultProgram();
1.175 + activateProgram();
1.176 +
1.177 + GLES20.glEnable(GLES20.GL_BLEND);
1.178 + GLES20.glBlendFunc(GLES20.GL_SRC_ALPHA, GLES20.GL_ONE_MINUS_SRC_ALPHA);
1.179 +
1.180 + if (mVertical) {
1.181 + getVerticalRect(context, mBarRectF);
1.182 + } else {
1.183 + getHorizontalRect(context, mBarRectF);
1.184 + }
1.185 + RectUtils.round(mBarRectF, mBarRect);
1.186 +
1.187 + GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
1.188 + GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, getTextureID());
1.189 +
1.190 + float viewWidth = context.viewport.width();
1.191 + float viewHeight = context.viewport.height();
1.192 +
1.193 + mBarRectF.set(mBarRect.left, viewHeight - mBarRect.top, mBarRect.right, viewHeight - mBarRect.bottom);
1.194 + mBarRectF.offset(context.offset.x, -context.offset.y);
1.195 +
1.196 + // We take a 1-pixel slice from the center of the image and scale it to become the bar
1.197 + fillRectCoordBuffer(mCoords, mBarRectF, viewWidth, viewHeight, mBodyTexCoords, mTexWidth, mTexHeight);
1.198 +
1.199 + // Get the buffer and handles from the context
1.200 + FloatBuffer coordBuffer = context.coordBuffer;
1.201 + int positionHandle = mPositionHandle;
1.202 + int textureHandle = mTextureHandle;
1.203 +
1.204 + // Make sure we are at position zero in the buffer in case other draw methods did not
1.205 + // clean up after themselves
1.206 + coordBuffer.position(0);
1.207 + coordBuffer.put(mCoords);
1.208 +
1.209 + // Unbind any the current array buffer so we can use client side buffers
1.210 + GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER, 0);
1.211 +
1.212 + // Vertex coordinates are x,y,z starting at position 0 into the buffer.
1.213 + coordBuffer.position(0);
1.214 + GLES20.glVertexAttribPointer(positionHandle, 3, GLES20.GL_FLOAT, false, 20, coordBuffer);
1.215 +
1.216 + // Texture coordinates are texture_x, texture_y starting at position 3 into the buffer.
1.217 + coordBuffer.position(3);
1.218 + GLES20.glVertexAttribPointer(textureHandle, 2, GLES20.GL_FLOAT, false, 20, coordBuffer);
1.219 +
1.220 + GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
1.221 +
1.222 + // Reset the position in the buffer for the next set of vertex and texture coordinates.
1.223 + coordBuffer.position(0);
1.224 + if (mVertical) {
1.225 + // top endcap
1.226 + mCapRectF.set(mBarRectF.left, mBarRectF.top + mCapLength, mBarRectF.right, mBarRectF.top);
1.227 + } else {
1.228 + // left endcap
1.229 + mCapRectF.set(mBarRectF.left - mCapLength, mBarRectF.bottom + mBarWidth, mBarRectF.left, mBarRectF.bottom);
1.230 + }
1.231 +
1.232 + fillRectCoordBuffer(mCoords, mCapRectF, viewWidth, viewHeight, mStartCapTexCoords, mTexWidth, mTexHeight);
1.233 + coordBuffer.put(mCoords);
1.234 +
1.235 + // Vertex coordinates are x,y,z starting at position 0 into the buffer.
1.236 + coordBuffer.position(0);
1.237 + GLES20.glVertexAttribPointer(positionHandle, 3, GLES20.GL_FLOAT, false, 20, coordBuffer);
1.238 +
1.239 + // Texture coordinates are texture_x, texture_y starting at position 3 into the buffer.
1.240 + coordBuffer.position(3);
1.241 + GLES20.glVertexAttribPointer(textureHandle, 2, GLES20.GL_FLOAT, false, 20, coordBuffer);
1.242 +
1.243 + GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
1.244 +
1.245 + // Reset the position in the buffer for the next set of vertex and texture coordinates.
1.246 + coordBuffer.position(0);
1.247 + if (mVertical) {
1.248 + // bottom endcap
1.249 + mCapRectF.set(mBarRectF.left, mBarRectF.bottom, mBarRectF.right, mBarRectF.bottom - mCapLength);
1.250 + } else {
1.251 + // right endcap
1.252 + mCapRectF.set(mBarRectF.right, mBarRectF.bottom + mBarWidth, mBarRectF.right + mCapLength, mBarRectF.bottom);
1.253 + }
1.254 + fillRectCoordBuffer(mCoords, mCapRectF, viewWidth, viewHeight, mEndCapTexCoords, mTexWidth, mTexHeight);
1.255 + coordBuffer.put(mCoords);
1.256 +
1.257 + // Vertex coordinates are x,y,z starting at position 0 into the buffer.
1.258 + coordBuffer.position(0);
1.259 + GLES20.glVertexAttribPointer(positionHandle, 3, GLES20.GL_FLOAT, false, 20, coordBuffer);
1.260 +
1.261 + // Texture coordinates are texture_x, texture_y starting at position 3 into the buffer.
1.262 + coordBuffer.position(3);
1.263 + GLES20.glVertexAttribPointer(textureHandle, 2, GLES20.GL_FLOAT, false, 20, coordBuffer);
1.264 +
1.265 + GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
1.266 +
1.267 + // Reset the position in the buffer for the next set of vertex and texture coordinates.
1.268 + coordBuffer.position(0);
1.269 +
1.270 + // Enable the default shader program again
1.271 + deactivateProgram();
1.272 + mRenderer.activateDefaultProgram();
1.273 + }
1.274 +
1.275 + private void getVerticalRect(RenderContext context, RectF dest) {
1.276 + RectF viewport = context.viewport;
1.277 + RectF pageRect = context.pageRect;
1.278 + float viewportHeight = viewport.height() - context.offset.y;
1.279 + float barStart = ((viewport.top - context.offset.y - pageRect.top) * (viewportHeight / pageRect.height())) + mCapLength;
1.280 + float barEnd = ((viewport.bottom - context.offset.y - pageRect.top) * (viewportHeight / pageRect.height())) - mCapLength;
1.281 + if (barStart > barEnd) {
1.282 + float middle = (barStart + barEnd) / 2.0f;
1.283 + barStart = barEnd = middle;
1.284 + }
1.285 + dest.set(viewport.width() - mBarWidth, barStart, viewport.width(), barEnd);
1.286 + }
1.287 +
1.288 + private void getHorizontalRect(RenderContext context, RectF dest) {
1.289 + RectF viewport = context.viewport;
1.290 + RectF pageRect = context.pageRect;
1.291 + float viewportWidth = viewport.width() - context.offset.x;
1.292 + float barStart = ((viewport.left - context.offset.x - pageRect.left) * (viewport.width() / pageRect.width())) + mCapLength;
1.293 + float barEnd = ((viewport.right - context.offset.x - pageRect.left) * (viewport.width() / pageRect.width())) - mCapLength;
1.294 + if (barStart > barEnd) {
1.295 + float middle = (barStart + barEnd) / 2.0f;
1.296 + barStart = barEnd = middle;
1.297 + }
1.298 + dest.set(barStart, viewport.height() - mBarWidth, barEnd, viewport.height());
1.299 + }
1.300 +}
