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 * Standard quantized DPI for extra-extra-high-density screens. 124 */ 125 public static final int DENSITY_XXHIGH = 480; 126 127 /** 128 * Intermediate density for screens that sit somewhere between 129 * {@link #DENSITY_XXHIGH} (480 dpi) and {@link #DENSITY_XXXHIGH} (640 dpi). 130 * This is not a density that applications should target, instead relying 131 * on the system to scale their {@link #DENSITY_XXXHIGH} assets for them. 132 */ 133 public static final int DENSITY_560 = 560; 134 135 /** 136 * Standard quantized DPI for extra-extra-extra-high-density screens. Applications 137 * should not generally worry about this density; relying on XHIGH graphics 138 * being scaled up to it should be sufficient for almost all cases. A typical 139 * use of this density would be 4K television screens -- 3840x2160, which 140 * is 2x a traditional HD 1920x1080 screen which runs at DENSITY_XHIGH. 141 */ 142 public static final int DENSITY_XXXHIGH = 640; 143 144 /** 145 * The reference density used throughout the system. 146 */ 147 public static final int DENSITY_DEFAULT = DENSITY_MEDIUM; 148 149 /** 150 * Scaling factor to convert a density in DPI units to the density scale. 151 * @hide 152 */ 153 public static final float DENSITY_DEFAULT_SCALE = 1.0f / DENSITY_DEFAULT; 154 155 /** 156 * The device's current density. 157 * <p> 158 * This value reflects any changes made to the device density. To obtain 159 * the device's stable density, use {@link #DENSITY_DEVICE_STABLE}. 160 * 161 * @hide This value should not be used. 162 * @deprecated Use {@link #DENSITY_DEVICE_STABLE} to obtain the stable 163 * device density or {@link #densityDpi} to obtain the current 164 * density for a specific display. 165 */ 166 @Deprecated 167 public static int DENSITY_DEVICE = getDeviceDensity(); 168 169 /** 170 * The device's stable density. 171 * <p> 172 * This value is constant at run time and may not reflect the current 173 * display density. To obtain the current density for a specific display, 174 * use {@link #densityDpi}. 175 */ 176 public static final int DENSITY_DEVICE_STABLE = getDeviceDensity(); 177 178 /** 179 * The absolute width of the available display size in pixels. 180 */ 181 public int widthPixels; 182 /** 183 * The absolute height of the available display size in pixels. 184 */ 185 public int heightPixels; 186 /** 187 * The logical density of the display. This is a scaling factor for the 188 * Density Independent Pixel unit, where one DIP is one pixel on an 189 * approximately 160 dpi screen (for example a 240x320, 1.5"x2" screen), 190 * providing the baseline of the system's display. Thus on a 160dpi screen 191 * this density value will be 1; on a 120 dpi screen it would be .75; etc. 192 * 193 * <p>This value does not exactly follow the real screen size (as given by 194 * {@link #xdpi} and {@link #ydpi}, but rather is used to scale the size of 195 * the overall UI in steps based on gross changes in the display dpi. For 196 * example, a 240x320 screen will have a density of 1 even if its width is 197 * 1.8", 1.3", etc. However, if the screen resolution is increased to 198 * 320x480 but the screen size remained 1.5"x2" then the density would be 199 * increased (probably to 1.5). 200 * 201 * @see #DENSITY_DEFAULT 202 */ 203 public float density; 204 /** 205 * The screen density expressed as dots-per-inch. May be either 206 * {@link #DENSITY_LOW}, {@link #DENSITY_MEDIUM}, or {@link #DENSITY_HIGH}. 207 */ 208 public int densityDpi; 209 /** 210 * A scaling factor for fonts displayed on the display. This is the same 211 * as {@link #density}, except that it may be adjusted in smaller 212 * increments at runtime based on a user preference for the font size. 213 */ 214 public float scaledDensity; 215 /** 216 * The exact physical pixels per inch of the screen in the X dimension. 217 */ 218 public float xdpi; 219 /** 220 * The exact physical pixels per inch of the screen in the Y dimension. 221 */ 222 public float ydpi; 223 224 /** 225 * The reported display width prior to any compatibility mode scaling 226 * being applied. 227 * @hide 228 */ 229 public int noncompatWidthPixels; 230 /** 231 * The reported display height prior to any compatibility mode scaling 232 * being applied. 233 * @hide 234 */ 235 public int noncompatHeightPixels; 236 /** 237 * The reported display density prior to any compatibility mode scaling 238 * being applied. 239 * @hide 240 */ 241 public float noncompatDensity; 242 /** 243 * The reported display density prior to any compatibility mode scaling 244 * being applied. 245 * @hide 246 */ 247 public int noncompatDensityDpi; 248 /** 249 * The reported scaled density prior to any compatibility mode scaling 250 * being applied. 251 * @hide 252 */ 253 public float noncompatScaledDensity; 254 /** 255 * The reported display xdpi prior to any compatibility mode scaling 256 * being applied. 257 * @hide 258 */ 259 public float noncompatXdpi; 260 /** 261 * The reported display ydpi prior to any compatibility mode scaling 262 * being applied. 263 * @hide 264 */ 265 public float noncompatYdpi; 266 DisplayMetrics()267 public DisplayMetrics() { 268 } 269 setTo(DisplayMetrics o)270 public void setTo(DisplayMetrics o) { 271 widthPixels = o.widthPixels; 272 heightPixels = o.heightPixels; 273 density = o.density; 274 densityDpi = o.densityDpi; 275 scaledDensity = o.scaledDensity; 276 xdpi = o.xdpi; 277 ydpi = o.ydpi; 278 noncompatWidthPixels = o.noncompatWidthPixels; 279 noncompatHeightPixels = o.noncompatHeightPixels; 280 noncompatDensity = o.noncompatDensity; 281 noncompatDensityDpi = o.noncompatDensityDpi; 282 noncompatScaledDensity = o.noncompatScaledDensity; 283 noncompatXdpi = o.noncompatXdpi; 284 noncompatYdpi = o.noncompatYdpi; 285 } 286 setToDefaults()287 public void setToDefaults() { 288 widthPixels = 0; 289 heightPixels = 0; 290 density = DENSITY_DEVICE / (float) DENSITY_DEFAULT; 291 densityDpi = DENSITY_DEVICE; 292 scaledDensity = density; 293 xdpi = DENSITY_DEVICE; 294 ydpi = DENSITY_DEVICE; 295 noncompatWidthPixels = widthPixels; 296 noncompatHeightPixels = heightPixels; 297 noncompatDensity = density; 298 noncompatDensityDpi = densityDpi; 299 noncompatScaledDensity = scaledDensity; 300 noncompatXdpi = xdpi; 301 noncompatYdpi = ydpi; 302 } 303 304 @Override equals(Object o)305 public boolean equals(Object o) { 306 return o instanceof DisplayMetrics && equals((DisplayMetrics)o); 307 } 308 309 /** 310 * Returns true if these display metrics equal the other display metrics. 311 * 312 * @param other The display metrics with which to compare. 313 * @return True if the display metrics are equal. 314 */ equals(DisplayMetrics other)315 public boolean equals(DisplayMetrics other) { 316 return equalsPhysical(other) 317 && scaledDensity == other.scaledDensity 318 && noncompatScaledDensity == other.noncompatScaledDensity; 319 } 320 321 /** 322 * Returns true if the physical aspects of the two display metrics 323 * are equal. This ignores the scaled density, which is a logical 324 * attribute based on the current desired font size. 325 * 326 * @param other The display metrics with which to compare. 327 * @return True if the display metrics are equal. 328 * @hide 329 */ equalsPhysical(DisplayMetrics other)330 public boolean equalsPhysical(DisplayMetrics other) { 331 return other != null 332 && widthPixels == other.widthPixels 333 && heightPixels == other.heightPixels 334 && density == other.density 335 && densityDpi == other.densityDpi 336 && xdpi == other.xdpi 337 && ydpi == other.ydpi 338 && noncompatWidthPixels == other.noncompatWidthPixels 339 && noncompatHeightPixels == other.noncompatHeightPixels 340 && noncompatDensity == other.noncompatDensity 341 && noncompatDensityDpi == other.noncompatDensityDpi 342 && noncompatXdpi == other.noncompatXdpi 343 && noncompatYdpi == other.noncompatYdpi; 344 } 345 346 @Override hashCode()347 public int hashCode() { 348 return widthPixels * heightPixels * densityDpi; 349 } 350 351 @Override toString()352 public String toString() { 353 return "DisplayMetrics{density=" + density + ", width=" + widthPixels + 354 ", height=" + heightPixels + ", scaledDensity=" + scaledDensity + 355 ", xdpi=" + xdpi + ", ydpi=" + ydpi + "}"; 356 } 357 getDeviceDensity()358 private static int getDeviceDensity() { 359 // qemu.sf.lcd_density can be used to override ro.sf.lcd_density 360 // when running in the emulator, allowing for dynamic configurations. 361 // The reason for this is that ro.sf.lcd_density is write-once and is 362 // set by the init process when it parses build.prop before anything else. 363 return SystemProperties.getInt("qemu.sf.lcd_density", 364 SystemProperties.getInt("ro.sf.lcd_density", DENSITY_DEFAULT)); 365 } 366 } 367