1 /* 2 * Copyright (C) 2006 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.util; 18 19 import android.os.SystemProperties; 20 21 22 /** 23 * A structure describing general information about a display, such as its 24 * size, density, and font scaling. 25 * <p>To access the DisplayMetrics members, initialize an object like this:</p> 26 * <pre> DisplayMetrics metrics = new DisplayMetrics(); 27 * getWindowManager().getDefaultDisplay().getMetrics(metrics);</pre> 28 */ 29 public class DisplayMetrics { 30 /** 31 * Standard quantized DPI for low-density screens. 32 */ 33 public static final int DENSITY_LOW = 120; 34 35 /** 36 * Standard quantized DPI for medium-density screens. 37 */ 38 public static final int DENSITY_MEDIUM = 160; 39 40 /** 41 * This is a secondary density, added for some common screen configurations. 42 * It is recommended that applications not generally target this as a first 43 * class density -- that is, don't supply specific graphics for this 44 * density, instead allow the platform to scale from other densities 45 * (typically {@link #DENSITY_HIGH}) as 46 * appropriate. In most cases (such as using bitmaps in 47 * {@link android.graphics.drawable.Drawable}) the platform 48 * can perform this scaling at load time, so the only cost is some slight 49 * startup runtime overhead. 50 * 51 * <p>This density was original introduced to correspond with a 52 * 720p TV screen: the density for 1080p televisions is 53 * {@link #DENSITY_XHIGH}, and the value here provides the same UI 54 * size for a TV running at 720p. It has also found use in 7" tablets, 55 * when these devices have 1280x720 displays. 56 */ 57 public static final int DENSITY_TV = 213; 58 59 /** 60 * Standard quantized DPI for high-density screens. 61 */ 62 public static final int DENSITY_HIGH = 240; 63 64 /** 65 * Intermediate density for screens that sit between {@link #DENSITY_HIGH} (240dpi) and 66 * {@link #DENSITY_XHIGH} (320dpi). This is not a density that applications should target, 67 * instead relying on the system to scale their {@link #DENSITY_XHIGH} assets for them. 68 */ 69 public static final int DENSITY_260 = 260; 70 71 /** 72 * Intermediate density for screens that sit between {@link #DENSITY_HIGH} (240dpi) and 73 * {@link #DENSITY_XHIGH} (320dpi). This is not a density that applications should target, 74 * instead relying on the system to scale their {@link #DENSITY_XHIGH} assets for them. 75 */ 76 public static final int DENSITY_280 = 280; 77 78 /** 79 * Intermediate density for screens that sit between {@link #DENSITY_HIGH} (240dpi) and 80 * {@link #DENSITY_XHIGH} (320dpi). This is not a density that applications should target, 81 * instead relying on the system to scale their {@link #DENSITY_XHIGH} assets for them. 82 */ 83 public static final int DENSITY_300 = 300; 84 85 /** 86 * Standard quantized DPI for extra-high-density screens. 87 */ 88 public static final int DENSITY_XHIGH = 320; 89 90 /** 91 * Intermediate density for screens that sit somewhere between 92 * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi). 93 * This is not a density that applications should target, instead relying 94 * on the system to scale their {@link #DENSITY_XXHIGH} assets for them. 95 */ 96 public static final int DENSITY_340 = 340; 97 98 /** 99 * Intermediate density for screens that sit somewhere between 100 * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi). 101 * This is not a density that applications should target, instead relying 102 * on the system to scale their {@link #DENSITY_XXHIGH} assets for them. 103 */ 104 public static final int DENSITY_360 = 360; 105 106 /** 107 * Intermediate density for screens that sit somewhere between 108 * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi). 109 * This is not a density that applications should target, instead relying 110 * on the system to scale their {@link #DENSITY_XXHIGH} assets for them. 111 */ 112 public static final int DENSITY_400 = 400; 113 114 /** 115 * Intermediate density for screens that sit somewhere between 116 * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi). 117 * This is not a density that applications should target, instead relying 118 * on the system to scale their {@link #DENSITY_XXHIGH} assets for them. 119 */ 120 public static final int DENSITY_420 = 420; 121 122 /** 123 * Intermediate density for screens that sit somewhere between 124 * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi). 125 * This is not a density that applications should target, instead relying 126 * on the system to scale their {@link #DENSITY_XXHIGH} assets for them. 127 */ 128 public static final int DENSITY_440 = 440; 129 130 /** 131 * Standard quantized DPI for extra-extra-high-density screens. 132 */ 133 public static final int DENSITY_XXHIGH = 480; 134 135 /** 136 * Intermediate density for screens that sit somewhere between 137 * {@link #DENSITY_XXHIGH} (480 dpi) and {@link #DENSITY_XXXHIGH} (640 dpi). 138 * This is not a density that applications should target, instead relying 139 * on the system to scale their {@link #DENSITY_XXXHIGH} assets for them. 140 */ 141 public static final int DENSITY_560 = 560; 142 143 /** 144 * Standard quantized DPI for extra-extra-extra-high-density screens. Applications 145 * should not generally worry about this density; relying on XHIGH graphics 146 * being scaled up to it should be sufficient for almost all cases. A typical 147 * use of this density would be 4K television screens -- 3840x2160, which 148 * is 2x a traditional HD 1920x1080 screen which runs at DENSITY_XHIGH. 149 */ 150 public static final int DENSITY_XXXHIGH = 640; 151 152 /** 153 * The reference density used throughout the system. 154 */ 155 public static final int DENSITY_DEFAULT = DENSITY_MEDIUM; 156 157 /** 158 * Scaling factor to convert a density in DPI units to the density scale. 159 * @hide 160 */ 161 public static final float DENSITY_DEFAULT_SCALE = 1.0f / DENSITY_DEFAULT; 162 163 /** 164 * The device's current density. 165 * <p> 166 * This value reflects any changes made to the device density. To obtain 167 * the device's stable density, use {@link #DENSITY_DEVICE_STABLE}. 168 * 169 * @hide This value should not be used. 170 * @deprecated Use {@link #DENSITY_DEVICE_STABLE} to obtain the stable 171 * device density or {@link #densityDpi} to obtain the current 172 * density for a specific display. 173 */ 174 @Deprecated 175 public static int DENSITY_DEVICE = getDeviceDensity(); 176 177 /** 178 * The device's stable density. 179 * <p> 180 * This value is constant at run time and may not reflect the current 181 * display density. To obtain the current density for a specific display, 182 * use {@link #densityDpi}. 183 */ 184 public static final int DENSITY_DEVICE_STABLE = getDeviceDensity(); 185 186 /** 187 * The absolute width of the available display size in pixels. 188 */ 189 public int widthPixels; 190 /** 191 * The absolute height of the available display size in pixels. 192 */ 193 public int heightPixels; 194 /** 195 * The logical density of the display. This is a scaling factor for the 196 * Density Independent Pixel unit, where one DIP is one pixel on an 197 * approximately 160 dpi screen (for example a 240x320, 1.5"x2" screen), 198 * providing the baseline of the system's display. Thus on a 160dpi screen 199 * this density value will be 1; on a 120 dpi screen it would be .75; etc. 200 * 201 * <p>This value does not exactly follow the real screen size (as given by 202 * {@link #xdpi} and {@link #ydpi}, but rather is used to scale the size of 203 * the overall UI in steps based on gross changes in the display dpi. For 204 * example, a 240x320 screen will have a density of 1 even if its width is 205 * 1.8", 1.3", etc. However, if the screen resolution is increased to 206 * 320x480 but the screen size remained 1.5"x2" then the density would be 207 * increased (probably to 1.5). 208 * 209 * @see #DENSITY_DEFAULT 210 */ 211 public float density; 212 /** 213 * The screen density expressed as dots-per-inch. May be either 214 * {@link #DENSITY_LOW}, {@link #DENSITY_MEDIUM}, or {@link #DENSITY_HIGH}. 215 */ 216 public int densityDpi; 217 /** 218 * A scaling factor for fonts displayed on the display. This is the same 219 * as {@link #density}, except that it may be adjusted in smaller 220 * increments at runtime based on a user preference for the font size. 221 */ 222 public float scaledDensity; 223 /** 224 * The exact physical pixels per inch of the screen in the X dimension. 225 */ 226 public float xdpi; 227 /** 228 * The exact physical pixels per inch of the screen in the Y dimension. 229 */ 230 public float ydpi; 231 232 /** 233 * The reported display width prior to any compatibility mode scaling 234 * being applied. 235 * @hide 236 */ 237 public int noncompatWidthPixels; 238 /** 239 * The reported display height prior to any compatibility mode scaling 240 * being applied. 241 * @hide 242 */ 243 public int noncompatHeightPixels; 244 /** 245 * The reported display density prior to any compatibility mode scaling 246 * being applied. 247 * @hide 248 */ 249 public float noncompatDensity; 250 /** 251 * The reported display density prior to any compatibility mode scaling 252 * being applied. 253 * @hide 254 */ 255 public int noncompatDensityDpi; 256 /** 257 * The reported scaled density prior to any compatibility mode scaling 258 * being applied. 259 * @hide 260 */ 261 public float noncompatScaledDensity; 262 /** 263 * The reported display xdpi prior to any compatibility mode scaling 264 * being applied. 265 * @hide 266 */ 267 public float noncompatXdpi; 268 /** 269 * The reported display ydpi prior to any compatibility mode scaling 270 * being applied. 271 * @hide 272 */ 273 public float noncompatYdpi; 274 275 public DisplayMetrics() { 276 } 277 278 public void setTo(DisplayMetrics o) { 279 if (this == o) { 280 return; 281 } 282 283 widthPixels = o.widthPixels; 284 heightPixels = o.heightPixels; 285 density = o.density; 286 densityDpi = o.densityDpi; 287 scaledDensity = o.scaledDensity; 288 xdpi = o.xdpi; 289 ydpi = o.ydpi; 290 noncompatWidthPixels = o.noncompatWidthPixels; 291 noncompatHeightPixels = o.noncompatHeightPixels; 292 noncompatDensity = o.noncompatDensity; 293 noncompatDensityDpi = o.noncompatDensityDpi; 294 noncompatScaledDensity = o.noncompatScaledDensity; 295 noncompatXdpi = o.noncompatXdpi; 296 noncompatYdpi = o.noncompatYdpi; 297 } 298 299 public void setToDefaults() { 300 widthPixels = 0; 301 heightPixels = 0; 302 density = DENSITY_DEVICE / (float) DENSITY_DEFAULT; 303 densityDpi = DENSITY_DEVICE; 304 scaledDensity = density; 305 xdpi = DENSITY_DEVICE; 306 ydpi = DENSITY_DEVICE; 307 noncompatWidthPixels = widthPixels; 308 noncompatHeightPixels = heightPixels; 309 noncompatDensity = density; 310 noncompatDensityDpi = densityDpi; 311 noncompatScaledDensity = scaledDensity; 312 noncompatXdpi = xdpi; 313 noncompatYdpi = ydpi; 314 } 315 316 @Override 317 public boolean equals(Object o) { 318 return o instanceof DisplayMetrics && equals((DisplayMetrics)o); 319 } 320 321 /** 322 * Returns true if these display metrics equal the other display metrics. 323 * 324 * @param other The display metrics with which to compare. 325 * @return True if the display metrics are equal. 326 */ 327 public boolean equals(DisplayMetrics other) { 328 return equalsPhysical(other) 329 && scaledDensity == other.scaledDensity 330 && noncompatScaledDensity == other.noncompatScaledDensity; 331 } 332 333 /** 334 * Returns true if the physical aspects of the two display metrics 335 * are equal. This ignores the scaled density, which is a logical 336 * attribute based on the current desired font size. 337 * 338 * @param other The display metrics with which to compare. 339 * @return True if the display metrics are equal. 340 * @hide 341 */ 342 public boolean equalsPhysical(DisplayMetrics other) { 343 return other != null 344 && widthPixels == other.widthPixels 345 && heightPixels == other.heightPixels 346 && density == other.density 347 && densityDpi == other.densityDpi 348 && xdpi == other.xdpi 349 && ydpi == other.ydpi 350 && noncompatWidthPixels == other.noncompatWidthPixels 351 && noncompatHeightPixels == other.noncompatHeightPixels 352 && noncompatDensity == other.noncompatDensity 353 && noncompatDensityDpi == other.noncompatDensityDpi 354 && noncompatXdpi == other.noncompatXdpi 355 && noncompatYdpi == other.noncompatYdpi; 356 } 357 358 @Override 359 public int hashCode() { 360 return widthPixels * heightPixels * densityDpi; 361 } 362 363 @Override 364 public String toString() { 365 return "DisplayMetrics{density=" + density + ", width=" + widthPixels + 366 ", height=" + heightPixels + ", scaledDensity=" + scaledDensity + 367 ", xdpi=" + xdpi + ", ydpi=" + ydpi + "}"; 368 } 369 370 private static int getDeviceDensity() { 371 // qemu.sf.lcd_density can be used to override ro.sf.lcd_density 372 // when running in the emulator, allowing for dynamic configurations. 373 // The reason for this is that ro.sf.lcd_density is write-once and is 374 // set by the init process when it parses build.prop before anything else. 375 return SystemProperties.getInt("qemu.sf.lcd_density", 376 SystemProperties.getInt("ro.sf.lcd_density", DENSITY_DEFAULT)); 377 } 378 } 379
