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_280 = 280; 70 71 /** 72 * Standard quantized DPI for extra-high-density screens. 73 */ 74 public static final int DENSITY_XHIGH = 320; 75 76 /** 77 * Intermediate density for screens that sit somewhere between 78 * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi). 79 * This is not a density that applications should target, instead relying 80 * on the system to scale their {@link #DENSITY_XXHIGH} assets for them. 81 */ 82 public static final int DENSITY_360 = 360; 83 84 /** 85 * Intermediate density for screens that sit somewhere between 86 * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi). 87 * This is not a density that applications should target, instead relying 88 * on the system to scale their {@link #DENSITY_XXHIGH} assets for them. 89 */ 90 public static final int DENSITY_400 = 400; 91 92 /** 93 * Intermediate density for screens that sit somewhere between 94 * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi). 95 * This is not a density that applications should target, instead relying 96 * on the system to scale their {@link #DENSITY_XXHIGH} assets for them. 97 */ 98 public static final int DENSITY_420 = 420; 99 100 /** 101 * Standard quantized DPI for extra-extra-high-density screens. 102 */ 103 public static final int DENSITY_XXHIGH = 480; 104 105 /** 106 * Intermediate density for screens that sit somewhere between 107 * {@link #DENSITY_XXHIGH} (480 dpi) and {@link #DENSITY_XXXHIGH} (640 dpi). 108 * This is not a density that applications should target, instead relying 109 * on the system to scale their {@link #DENSITY_XXXHIGH} assets for them. 110 */ 111 public static final int DENSITY_560 = 560; 112 113 /** 114 * Standard quantized DPI for extra-extra-extra-high-density screens. Applications 115 * should not generally worry about this density; relying on XHIGH graphics 116 * being scaled up to it should be sufficient for almost all cases. A typical 117 * use of this density would be 4K television screens -- 3840x2160, which 118 * is 2x a traditional HD 1920x1080 screen which runs at DENSITY_XHIGH. 119 */ 120 public static final int DENSITY_XXXHIGH = 640; 121 122 /** 123 * The reference density used throughout the system. 124 */ 125 public static final int DENSITY_DEFAULT = DENSITY_MEDIUM; 126 127 /** 128 * Scaling factor to convert a density in DPI units to the density scale. 129 * @hide 130 */ 131 public static final float DENSITY_DEFAULT_SCALE = 1.0f / DENSITY_DEFAULT; 132 133 /** 134 * The device's current density. 135 * <p> 136 * This value reflects any changes made to the device density. To obtain 137 * the device's stable density, use {@link #DENSITY_DEVICE_STABLE}. 138 * 139 * @hide This value should not be used. 140 * @deprecated Use {@link #DENSITY_DEVICE_STABLE} to obtain the stable 141 * device density or {@link #densityDpi} to obtain the current 142 * density for a specific display. 143 */ 144 @Deprecated 145 public static int DENSITY_DEVICE = getDeviceDensity(); 146 147 /** 148 * The device's stable density. 149 * <p> 150 * This value is constant at run time and may not reflect the current 151 * display density. To obtain the current density for a specific display, 152 * use {@link #densityDpi}. 153 */ 154 public static final int DENSITY_DEVICE_STABLE = getDeviceDensity(); 155 156 /** 157 * The absolute width of the available display size in pixels. 158 */ 159 public int widthPixels; 160 /** 161 * The absolute height of the available display size in pixels. 162 */ 163 public int heightPixels; 164 /** 165 * The logical density of the display. This is a scaling factor for the 166 * Density Independent Pixel unit, where one DIP is one pixel on an 167 * approximately 160 dpi screen (for example a 240x320, 1.5"x2" screen), 168 * providing the baseline of the system's display. Thus on a 160dpi screen 169 * this density value will be 1; on a 120 dpi screen it would be .75; etc. 170 * 171 * <p>This value does not exactly follow the real screen size (as given by 172 * {@link #xdpi} and {@link #ydpi}, but rather is used to scale the size of 173 * the overall UI in steps based on gross changes in the display dpi. For 174 * example, a 240x320 screen will have a density of 1 even if its width is 175 * 1.8", 1.3", etc. However, if the screen resolution is increased to 176 * 320x480 but the screen size remained 1.5"x2" then the density would be 177 * increased (probably to 1.5). 178 * 179 * @see #DENSITY_DEFAULT 180 */ 181 public float density; 182 /** 183 * The screen density expressed as dots-per-inch. May be either 184 * {@link #DENSITY_LOW}, {@link #DENSITY_MEDIUM}, or {@link #DENSITY_HIGH}. 185 */ 186 public int densityDpi; 187 /** 188 * A scaling factor for fonts displayed on the display. This is the same 189 * as {@link #density}, except that it may be adjusted in smaller 190 * increments at runtime based on a user preference for the font size. 191 */ 192 public float scaledDensity; 193 /** 194 * The exact physical pixels per inch of the screen in the X dimension. 195 */ 196 public float xdpi; 197 /** 198 * The exact physical pixels per inch of the screen in the Y dimension. 199 */ 200 public float ydpi; 201 202 /** 203 * The reported display width prior to any compatibility mode scaling 204 * being applied. 205 * @hide 206 */ 207 public int noncompatWidthPixels; 208 /** 209 * The reported display height prior to any compatibility mode scaling 210 * being applied. 211 * @hide 212 */ 213 public int noncompatHeightPixels; 214 /** 215 * The reported display density prior to any compatibility mode scaling 216 * being applied. 217 * @hide 218 */ 219 public float noncompatDensity; 220 /** 221 * The reported display density prior to any compatibility mode scaling 222 * being applied. 223 * @hide 224 */ 225 public int noncompatDensityDpi; 226 /** 227 * The reported scaled density prior to any compatibility mode scaling 228 * being applied. 229 * @hide 230 */ 231 public float noncompatScaledDensity; 232 /** 233 * The reported display xdpi prior to any compatibility mode scaling 234 * being applied. 235 * @hide 236 */ 237 public float noncompatXdpi; 238 /** 239 * The reported display ydpi prior to any compatibility mode scaling 240 * being applied. 241 * @hide 242 */ 243 public float noncompatYdpi; 244 245 public DisplayMetrics() { 246 } 247 248 public void setTo(DisplayMetrics o) { 249 widthPixels = o.widthPixels; 250 heightPixels = o.heightPixels; 251 density = o.density; 252 densityDpi = o.densityDpi; 253 scaledDensity = o.scaledDensity; 254 xdpi = o.xdpi; 255 ydpi = o.ydpi; 256 noncompatWidthPixels = o.noncompatWidthPixels; 257 noncompatHeightPixels = o.noncompatHeightPixels; 258 noncompatDensity = o.noncompatDensity; 259 noncompatDensityDpi = o.noncompatDensityDpi; 260 noncompatScaledDensity = o.noncompatScaledDensity; 261 noncompatXdpi = o.noncompatXdpi; 262 noncompatYdpi = o.noncompatYdpi; 263 } 264 265 public void setToDefaults() { 266 widthPixels = 0; 267 heightPixels = 0; 268 density = DENSITY_DEVICE / (float) DENSITY_DEFAULT; 269 densityDpi = DENSITY_DEVICE; 270 scaledDensity = density; 271 xdpi = DENSITY_DEVICE; 272 ydpi = DENSITY_DEVICE; 273 noncompatWidthPixels = widthPixels; 274 noncompatHeightPixels = heightPixels; 275 noncompatDensity = density; 276 noncompatDensityDpi = densityDpi; 277 noncompatScaledDensity = scaledDensity; 278 noncompatXdpi = xdpi; 279 noncompatYdpi = ydpi; 280 } 281 282 @Override 283 public boolean equals(Object o) { 284 return o instanceof DisplayMetrics && equals((DisplayMetrics)o); 285 } 286 287 /** 288 * Returns true if these display metrics equal the other display metrics. 289 * 290 * @param other The display metrics with which to compare. 291 * @return True if the display metrics are equal. 292 */ 293 public boolean equals(DisplayMetrics other) { 294 return equalsPhysical(other) 295 && scaledDensity == other.scaledDensity 296 && noncompatScaledDensity == other.noncompatScaledDensity; 297 } 298 299 /** 300 * Returns true if the physical aspects of the two display metrics 301 * are equal. This ignores the scaled density, which is a logical 302 * attribute based on the current desired font size. 303 * 304 * @param other The display metrics with which to compare. 305 * @return True if the display metrics are equal. 306 * @hide 307 */ 308 public boolean equalsPhysical(DisplayMetrics other) { 309 return other != null 310 && widthPixels == other.widthPixels 311 && heightPixels == other.heightPixels 312 && density == other.density 313 && densityDpi == other.densityDpi 314 && xdpi == other.xdpi 315 && ydpi == other.ydpi 316 && noncompatWidthPixels == other.noncompatWidthPixels 317 && noncompatHeightPixels == other.noncompatHeightPixels 318 && noncompatDensity == other.noncompatDensity 319 && noncompatDensityDpi == other.noncompatDensityDpi 320 && noncompatXdpi == other.noncompatXdpi 321 && noncompatYdpi == other.noncompatYdpi; 322 } 323 324 @Override 325 public int hashCode() { 326 return widthPixels * heightPixels * densityDpi; 327 } 328 329 @Override 330 public String toString() { 331 return "DisplayMetrics{density=" + density + ", width=" + widthPixels + 332 ", height=" + heightPixels + ", scaledDensity=" + scaledDensity + 333 ", xdpi=" + xdpi + ", ydpi=" + ydpi + "}"; 334 } 335 336 private static int getDeviceDensity() { 337 // qemu.sf.lcd_density can be used to override ro.sf.lcd_density 338 // when running in the emulator, allowing for dynamic configurations. 339 // The reason for this is that ro.sf.lcd_density is write-once and is 340 // set by the init process when it parses build.prop before anything else. 341 return SystemProperties.getInt("qemu.sf.lcd_density", 342 SystemProperties.getInt("ro.sf.lcd_density", DENSITY_DEFAULT)); 343 } 344 } 345
