1 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*- 2 * This Source Code Form is subject to the terms of the Mozilla Public 3 * License, v. 2.0. If a copy of the MPL was not distributed with this file, 4 * You can obtain one at http://mozilla.org/MPL/2.0/. */ 5 6 package org.mozilla.gecko.gfx; 7 8 import org.mozilla.gecko.annotation.WrapForJNI; 9 import org.mozilla.gecko.util.FloatUtils; 10 11 import android.graphics.PointF; 12 import android.graphics.RectF; 13 import android.util.DisplayMetrics; 14 15 /** 16 * ImmutableViewportMetrics are used to store the viewport metrics 17 * in way that we can access a version of them from multiple threads 18 * without having to take a lock 19 */ 20 public class ImmutableViewportMetrics { 21 22 // We need to flatten the RectF and FloatSize structures 23 // because Java doesn't have the concept of const classes 24 public final float pageRectLeft; 25 public final float pageRectTop; 26 public final float pageRectRight; 27 public final float pageRectBottom; 28 public final float cssPageRectLeft; 29 public final float cssPageRectTop; 30 public final float cssPageRectRight; 31 public final float cssPageRectBottom; 32 public final float viewportRectLeft; 33 public final float viewportRectTop; 34 public final int viewportRectWidth; 35 public final int viewportRectHeight; 36 37 public final float zoomFactor; 38 ImmutableViewportMetrics(DisplayMetrics metrics)39 public ImmutableViewportMetrics(DisplayMetrics metrics) { 40 viewportRectLeft = pageRectLeft = cssPageRectLeft = 0; 41 viewportRectTop = pageRectTop = cssPageRectTop = 0; 42 viewportRectWidth = metrics.widthPixels; 43 viewportRectHeight = metrics.heightPixels; 44 pageRectRight = cssPageRectRight = metrics.widthPixels; 45 pageRectBottom = cssPageRectBottom = metrics.heightPixels; 46 zoomFactor = 1.0f; 47 } 48 49 /** This constructor is used by native code in AndroidJavaWrappers.cpp, be 50 * careful when modifying the signature. 51 */ 52 @WrapForJNI(calledFrom = "gecko") ImmutableViewportMetrics(float aPageRectLeft, float aPageRectTop, float aPageRectRight, float aPageRectBottom, float aCssPageRectLeft, float aCssPageRectTop, float aCssPageRectRight, float aCssPageRectBottom, float aViewportRectLeft, float aViewportRectTop, int aViewportRectWidth, int aViewportRectHeight, float aZoomFactor)53 private ImmutableViewportMetrics(float aPageRectLeft, float aPageRectTop, 54 float aPageRectRight, float aPageRectBottom, float aCssPageRectLeft, 55 float aCssPageRectTop, float aCssPageRectRight, float aCssPageRectBottom, 56 float aViewportRectLeft, float aViewportRectTop, int aViewportRectWidth, 57 int aViewportRectHeight, float aZoomFactor) 58 { 59 pageRectLeft = aPageRectLeft; 60 pageRectTop = aPageRectTop; 61 pageRectRight = aPageRectRight; 62 pageRectBottom = aPageRectBottom; 63 cssPageRectLeft = aCssPageRectLeft; 64 cssPageRectTop = aCssPageRectTop; 65 cssPageRectRight = aCssPageRectRight; 66 cssPageRectBottom = aCssPageRectBottom; 67 viewportRectLeft = aViewportRectLeft; 68 viewportRectTop = aViewportRectTop; 69 viewportRectWidth = aViewportRectWidth; 70 viewportRectHeight = aViewportRectHeight; 71 zoomFactor = aZoomFactor; 72 } 73 getWidth()74 public float getWidth() { 75 return viewportRectWidth; 76 } 77 getHeight()78 public float getHeight() { 79 return viewportRectHeight; 80 } 81 viewportRectRight()82 public float viewportRectRight() { 83 return viewportRectLeft + viewportRectWidth; 84 } 85 viewportRectBottom()86 public float viewportRectBottom() { 87 return viewportRectTop + viewportRectHeight; 88 } 89 getOrigin()90 public PointF getOrigin() { 91 return new PointF(viewportRectLeft, viewportRectTop); 92 } 93 getSize()94 public FloatSize getSize() { 95 return new FloatSize(viewportRectWidth, viewportRectHeight); 96 } 97 getViewport()98 public RectF getViewport() { 99 return new RectF(viewportRectLeft, 100 viewportRectTop, 101 viewportRectRight(), 102 viewportRectBottom()); 103 } 104 getCssViewport()105 public RectF getCssViewport() { 106 return RectUtils.scale(getViewport(), 1 / zoomFactor); 107 } 108 getPageRect()109 public RectF getPageRect() { 110 return new RectF(pageRectLeft, pageRectTop, pageRectRight, pageRectBottom); 111 } 112 getPageWidth()113 public float getPageWidth() { 114 return pageRectRight - pageRectLeft; 115 } 116 getPageHeight()117 public float getPageHeight() { 118 return pageRectBottom - pageRectTop; 119 } 120 getCssPageRect()121 public RectF getCssPageRect() { 122 return new RectF(cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom); 123 } 124 getOverscroll()125 public RectF getOverscroll() { 126 return new RectF(Math.max(0, pageRectLeft - viewportRectLeft), 127 Math.max(0, pageRectTop - viewportRectTop), 128 Math.max(0, viewportRectRight() - pageRectRight), 129 Math.max(0, viewportRectBottom() - pageRectBottom)); 130 } 131 132 /* 133 * Returns the viewport metrics that represent a linear transition between "this" and "to" at 134 * time "t", which is on the scale [0, 1). This function interpolates all values stored in 135 * the viewport metrics. 136 */ interpolate(ImmutableViewportMetrics to, float t)137 public ImmutableViewportMetrics interpolate(ImmutableViewportMetrics to, float t) { 138 return new ImmutableViewportMetrics( 139 FloatUtils.interpolate(pageRectLeft, to.pageRectLeft, t), 140 FloatUtils.interpolate(pageRectTop, to.pageRectTop, t), 141 FloatUtils.interpolate(pageRectRight, to.pageRectRight, t), 142 FloatUtils.interpolate(pageRectBottom, to.pageRectBottom, t), 143 FloatUtils.interpolate(cssPageRectLeft, to.cssPageRectLeft, t), 144 FloatUtils.interpolate(cssPageRectTop, to.cssPageRectTop, t), 145 FloatUtils.interpolate(cssPageRectRight, to.cssPageRectRight, t), 146 FloatUtils.interpolate(cssPageRectBottom, to.cssPageRectBottom, t), 147 FloatUtils.interpolate(viewportRectLeft, to.viewportRectLeft, t), 148 FloatUtils.interpolate(viewportRectTop, to.viewportRectTop, t), 149 (int)FloatUtils.interpolate(viewportRectWidth, to.viewportRectWidth, t), 150 (int)FloatUtils.interpolate(viewportRectHeight, to.viewportRectHeight, t), 151 FloatUtils.interpolate(zoomFactor, to.zoomFactor, t)); 152 } 153 setViewportSize(int width, int height)154 public ImmutableViewportMetrics setViewportSize(int width, int height) { 155 if (width == viewportRectWidth && height == viewportRectHeight) { 156 return this; 157 } 158 159 return new ImmutableViewportMetrics( 160 pageRectLeft, pageRectTop, pageRectRight, pageRectBottom, 161 cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom, 162 viewportRectLeft, viewportRectTop, width, height, 163 zoomFactor); 164 } 165 setViewportOrigin(float newOriginX, float newOriginY)166 public ImmutableViewportMetrics setViewportOrigin(float newOriginX, float newOriginY) { 167 return new ImmutableViewportMetrics( 168 pageRectLeft, pageRectTop, pageRectRight, pageRectBottom, 169 cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom, 170 newOriginX, newOriginY, viewportRectWidth, viewportRectHeight, 171 zoomFactor); 172 } 173 setZoomFactor(float newZoomFactor)174 public ImmutableViewportMetrics setZoomFactor(float newZoomFactor) { 175 return new ImmutableViewportMetrics( 176 pageRectLeft, pageRectTop, pageRectRight, pageRectBottom, 177 cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom, 178 viewportRectLeft, viewportRectTop, viewportRectWidth, viewportRectHeight, 179 newZoomFactor); 180 } 181 offsetViewportBy(float dx, float dy)182 public ImmutableViewportMetrics offsetViewportBy(float dx, float dy) { 183 return setViewportOrigin(viewportRectLeft + dx, viewportRectTop + dy); 184 } 185 offsetViewportByAndClamp(float dx, float dy)186 public ImmutableViewportMetrics offsetViewportByAndClamp(float dx, float dy) { 187 return setViewportOrigin( 188 Math.max(pageRectLeft, Math.min(viewportRectLeft + dx, pageRectRight - getWidth())), 189 Math.max(pageRectTop, Math.min(viewportRectTop + dy, pageRectBottom - getHeight()))); 190 } 191 setPageRect(RectF pageRect, RectF cssPageRect)192 public ImmutableViewportMetrics setPageRect(RectF pageRect, RectF cssPageRect) { 193 return new ImmutableViewportMetrics( 194 pageRect.left, pageRect.top, pageRect.right, pageRect.bottom, 195 cssPageRect.left, cssPageRect.top, cssPageRect.right, cssPageRect.bottom, 196 viewportRectLeft, viewportRectTop, viewportRectWidth, viewportRectHeight, 197 zoomFactor); 198 } 199 setPageRectFrom(ImmutableViewportMetrics aMetrics)200 public ImmutableViewportMetrics setPageRectFrom(ImmutableViewportMetrics aMetrics) { 201 if (aMetrics.cssPageRectLeft == cssPageRectLeft && 202 aMetrics.cssPageRectTop == cssPageRectTop && 203 aMetrics.cssPageRectRight == cssPageRectRight && 204 aMetrics.cssPageRectBottom == cssPageRectBottom) { 205 return this; 206 } 207 RectF css = aMetrics.getCssPageRect(); 208 return setPageRect(RectUtils.scale(css, zoomFactor), css); 209 } 210 211 /* This will set the zoom factor and re-scale page-size and viewport offset 212 * accordingly. The given focus will remain at the same point on the screen 213 * after scaling. 214 */ scaleTo(float newZoomFactor, PointF focus)215 public ImmutableViewportMetrics scaleTo(float newZoomFactor, PointF focus) { 216 // cssPageRect* is invariant, since we're setting the scale factor 217 // here. The page rect is based on the CSS page rect. 218 float newPageRectLeft = cssPageRectLeft * newZoomFactor; 219 float newPageRectTop = cssPageRectTop * newZoomFactor; 220 float newPageRectRight = cssPageRectLeft + ((cssPageRectRight - cssPageRectLeft) * newZoomFactor); 221 float newPageRectBottom = cssPageRectTop + ((cssPageRectBottom - cssPageRectTop) * newZoomFactor); 222 223 PointF origin = getOrigin(); 224 origin.offset(focus.x, focus.y); 225 origin = PointUtils.scale(origin, newZoomFactor / zoomFactor); 226 origin.offset(-focus.x, -focus.y); 227 228 return new ImmutableViewportMetrics( 229 newPageRectLeft, newPageRectTop, newPageRectRight, newPageRectBottom, 230 cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom, 231 origin.x, origin.y, viewportRectWidth, viewportRectHeight, 232 newZoomFactor); 233 } 234 235 /** Clamps the viewport to remain within the page rect. */ clamp()236 public ImmutableViewportMetrics clamp() { 237 RectF newViewport = getViewport(); 238 239 // The viewport bounds ought to never exceed the page bounds. 240 if (newViewport.right > pageRectRight) 241 newViewport.offset((pageRectRight) - newViewport.right, 0); 242 if (newViewport.left < pageRectLeft) 243 newViewport.offset(pageRectLeft - newViewport.left, 0); 244 245 if (newViewport.bottom > pageRectBottom) 246 newViewport.offset(0, (pageRectBottom) - newViewport.bottom); 247 if (newViewport.top < pageRectTop) 248 newViewport.offset(0, pageRectTop - newViewport.top); 249 250 // Note that since newViewport is only translated around, the viewport's 251 // width and height are unchanged. 252 return new ImmutableViewportMetrics( 253 pageRectLeft, pageRectTop, pageRectRight, pageRectBottom, 254 cssPageRectLeft, cssPageRectTop, cssPageRectRight, cssPageRectBottom, 255 newViewport.left, newViewport.top, viewportRectWidth, viewportRectHeight, 256 zoomFactor); 257 } 258 fuzzyEquals(ImmutableViewportMetrics other)259 public boolean fuzzyEquals(ImmutableViewportMetrics other) { 260 // Don't bother checking the pageRectXXX values because they are a product 261 // of the cssPageRectXXX values and the zoomFactor, except with more rounding 262 // error. Checking those is both inefficient and can lead to false negatives. 263 return FloatUtils.fuzzyEquals(cssPageRectLeft, other.cssPageRectLeft) 264 && FloatUtils.fuzzyEquals(cssPageRectTop, other.cssPageRectTop) 265 && FloatUtils.fuzzyEquals(cssPageRectRight, other.cssPageRectRight) 266 && FloatUtils.fuzzyEquals(cssPageRectBottom, other.cssPageRectBottom) 267 && FloatUtils.fuzzyEquals(viewportRectLeft, other.viewportRectLeft) 268 && FloatUtils.fuzzyEquals(viewportRectTop, other.viewportRectTop) 269 && viewportRectWidth == other.viewportRectWidth 270 && viewportRectHeight == other.viewportRectHeight 271 && FloatUtils.fuzzyEquals(zoomFactor, other.zoomFactor); 272 } 273 274 @Override toString()275 public String toString() { 276 return "ImmutableViewportMetrics v=(" + viewportRectLeft + "," + viewportRectTop + "," 277 + viewportRectWidth + "x" + viewportRectHeight + ") p=(" + pageRectLeft + "," 278 + pageRectTop + "," + pageRectRight + "," + pageRectBottom + ") c=(" 279 + cssPageRectLeft + "," + cssPageRectTop + "," + cssPageRectRight + "," 280 + cssPageRectBottom + ") z=" + zoomFactor; 281 } 282 } 283