content: /*
   * Copyright (C) 2006 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package android.util;
  
  import android.annotation.UnsupportedAppUsage;
  import android.os.SystemProperties;
  
  
  /**
   * A structure describing general information about a display, such as its
   * size, density, and font scaling.
   * <p>To access the DisplayMetrics members, retrieve display metrics like this:</p>
   * <pre>context.getResources().getDisplayMetrics();</pre>
   */
  public class DisplayMetrics {
      /**
       * Standard quantized DPI for low-density screens.
       */
      public static final int DENSITY_LOW = 120;
  
      /**
       * Intermediate density for screens that sit between {@link #DENSITY_LOW} (120dpi) and
       * {@link #DENSITY_MEDIUM} (160dpi). This is not a density that applications should target,
       * instead relying on the system to scale their {@link #DENSITY_MEDIUM} assets for them.
       */
      public static final int DENSITY_140 = 140;
  
      /**
       * Standard quantized DPI for medium-density screens.
       */
      public static final int DENSITY_MEDIUM = 160;
  
      /**
       * Intermediate density for screens that sit between {@link #DENSITY_MEDIUM} (160dpi) and
       * {@link #DENSITY_HIGH} (240dpi). This is not a density that applications should target,
       * instead relying on the system to scale their {@link #DENSITY_HIGH} assets for them.
       */
      public static final int DENSITY_180 = 180;
  
      /**
       * Intermediate density for screens that sit between {@link #DENSITY_MEDIUM} (160dpi) and
       * {@link #DENSITY_HIGH} (240dpi). This is not a density that applications should target,
       * instead relying on the system to scale their {@link #DENSITY_HIGH} assets for them.
       */
      public static final int DENSITY_200 = 200;
  
      /**
       * This is a secondary density, added for some common screen configurations.
       * It is recommended that applications not generally target this as a first
       * class density -- that is, don't supply specific graphics for this
       * density, instead allow the platform to scale from other densities
       * (typically {@link #DENSITY_HIGH}) as
       * appropriate.  In most cases (such as using bitmaps in
       * {@link android.graphics.drawable.Drawable}) the platform
       * can perform this scaling at load time, so the only cost is some slight
       * startup runtime overhead.
       *
       * <p>This density was original introduced to correspond with a
       * 720p TV screen: the density for 1080p televisions is
       * {@link #DENSITY_XHIGH}, and the value here provides the same UI
       * size for a TV running at 720p.  It has also found use in 7" tablets,
       * when these devices have 1280x720 displays.
       */
      public static final int DENSITY_TV = 213;
  
      /**
       * Intermediate density for screens that sit between {@link #DENSITY_MEDIUM} (160dpi) and
       * {@link #DENSITY_HIGH} (240dpi). This is not a density that applications should target,
       * instead relying on the system to scale their {@link #DENSITY_HIGH} assets for them.
       */
      public static final int DENSITY_220 = 220;
  
      /**
       * Standard quantized DPI for high-density screens.
       */
      public static final int DENSITY_HIGH = 240;
  
      /**
       * Intermediate density for screens that sit between {@link #DENSITY_HIGH} (240dpi) and
       * {@link #DENSITY_XHIGH} (320dpi). This is not a density that applications should target,
       * instead relying on the system to scale their {@link #DENSITY_XHIGH} assets for them.
       */
      public static final int DENSITY_260 = 260;
  
      /**
       * Intermediate density for screens that sit between {@link #DENSITY_HIGH} (240dpi) and
       * {@link #DENSITY_XHIGH} (320dpi). This is not a density that applications should target,
       * instead relying on the system to scale their {@link #DENSITY_XHIGH} assets for them.
       */
      public static final int DENSITY_280 = 280;
  
      /**
       * Intermediate density for screens that sit between {@link #DENSITY_HIGH} (240dpi) and
       * {@link #DENSITY_XHIGH} (320dpi). This is not a density that applications should target,
       * instead relying on the system to scale their {@link #DENSITY_XHIGH} assets for them.
       */
      public static final int DENSITY_300 = 300;
  
      /**
       * Standard quantized DPI for extra-high-density screens.
       */
      public static final int DENSITY_XHIGH = 320;
  
      /**
       * Intermediate density for screens that sit somewhere between
       * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
       * This is not a density that applications should target, instead relying
       * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
       */
      public static final int DENSITY_340 = 340;
  
      /**
       * Intermediate density for screens that sit somewhere between
       * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
       * This is not a density that applications should target, instead relying
       * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
       */
      public static final int DENSITY_360 = 360;
  
      /**
       * Intermediate density for screens that sit somewhere between
       * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
       * This is not a density that applications should target, instead relying
       * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
       */
      public static final int DENSITY_400 = 400;
  
      /**
       * Intermediate density for screens that sit somewhere between
       * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
       * This is not a density that applications should target, instead relying
       * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
       */
      public static final int DENSITY_420 = 420;
  
      /**
       * Intermediate density for screens that sit somewhere between
       * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
       * This is not a density that applications should target, instead relying
       * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
       */
      public static final int DENSITY_440 = 440;
  
      /**
       * Intermediate density for screens that sit somewhere between
       * {@link #DENSITY_XHIGH} (320 dpi) and {@link #DENSITY_XXHIGH} (480 dpi).
       * This is not a density that applications should target, instead relying
       * on the system to scale their {@link #DENSITY_XXHIGH} assets for them.
       */
      public static final int DENSITY_450 = 450;
  
      /**
       * Standard quantized DPI for extra-extra-high-density screens.
       */
      public static final int DENSITY_XXHIGH = 480;
  
      /**
       * Intermediate density for screens that sit somewhere between
       * {@link #DENSITY_XXHIGH} (480 dpi) and {@link #DENSITY_XXXHIGH} (640 dpi).
       * This is not a density that applications should target, instead relying
       * on the system to scale their {@link #DENSITY_XXXHIGH} assets for them.
       */
      public static final int DENSITY_560 = 560;
  
      /**
       * Intermediate density for screens that sit somewhere between
       * {@link #DENSITY_XXHIGH} (480 dpi) and {@link #DENSITY_XXXHIGH} (640 dpi).
       * This is not a density that applications should target, instead relying
       * on the system to scale their {@link #DENSITY_XXXHIGH} assets for them.
       */
      public static final int DENSITY_600 = 600;
  
      /**
       * Standard quantized DPI for extra-extra-extra-high-density screens.  Applications
       * should not generally worry about this density; relying on XHIGH graphics
       * being scaled up to it should be sufficient for almost all cases.  A typical
       * use of this density would be 4K television screens -- 3840x2160, which
       * is 2x a traditional HD 1920x1080 screen which runs at DENSITY_XHIGH.
       */
      public static final int DENSITY_XXXHIGH = 640;
  
      /**
       * The reference density used throughout the system.
       */
      public static final int DENSITY_DEFAULT = DENSITY_MEDIUM;
  
      /**
       * Scaling factor to convert a density in DPI units to the density scale.
       * @hide
       */
      public static final float DENSITY_DEFAULT_SCALE = 1.0f / DENSITY_DEFAULT;
  
      /**
       * The device's current density.
       * <p>
       * This value reflects any changes made to the device density. To obtain
       * the device's stable density, use {@link #DENSITY_DEVICE_STABLE}.
       *
       * @hide This value should not be used.
       * @deprecated Use {@link #DENSITY_DEVICE_STABLE} to obtain the stable
       *             device density or {@link #densityDpi} to obtain the current
       *             density for a specific display.
       */
      @Deprecated
      @UnsupportedAppUsage
      public static int DENSITY_DEVICE = getDeviceDensity();
  
      /**
       * The device's stable density.
       * <p>
       * This value is constant at run time and may not reflect the current
       * display density. To obtain the current density for a specific display,
       * use {@link #densityDpi}.
       */
      public static final int DENSITY_DEVICE_STABLE = getDeviceDensity();
  
      /**
       * The absolute width of the available display size in pixels.
       */
      public int widthPixels;
      /**
       * The absolute height of the available display size in pixels.
       */
      public int heightPixels;
      /**
       * The logical density of the display.  This is a scaling factor for the
       * Density Independent Pixel unit, where one DIP is one pixel on an
       * approximately 160 dpi screen (for example a 240x320, 1.5"x2" screen), 
       * providing the baseline of the system's display. Thus on a 160dpi screen 
       * this density value will be 1; on a 120 dpi screen it would be .75; etc.
       *  
       * <p>This value does not exactly follow the real screen size (as given by 
       * {@link #xdpi} and {@link #ydpi}), but rather is used to scale the size of
       * the overall UI in steps based on gross changes in the display dpi.  For 
       * example, a 240x320 screen will have a density of 1 even if its width is 
       * 1.8", 1.3", etc. However, if the screen resolution is increased to 
       * 320x480 but the screen size remained 1.5"x2" then the density would be 
       * increased (probably to 1.5).
       *
       * @see #DENSITY_DEFAULT
       */
      public float density;
      /**
       * The screen density expressed as dots-per-inch.  May be either
       * {@link #DENSITY_LOW}, {@link #DENSITY_MEDIUM}, or {@link #DENSITY_HIGH}.
       */
      public int densityDpi;
      /**
       * A scaling factor for fonts displayed on the display.  This is the same
       * as {@link #density}, except that it may be adjusted in smaller
       * increments at runtime based on a user preference for the font size.
       */
      public float scaledDensity;
      /**
       * The exact physical pixels per inch of the screen in the X dimension.
       */
      public float xdpi;
      /**
       * The exact physical pixels per inch of the screen in the Y dimension.
       */
      public float ydpi;
  
      /**
       * The reported display width prior to any compatibility mode scaling
       * being applied.
       * @hide
       */
      @UnsupportedAppUsage
      public int noncompatWidthPixels;
      /**
       * The reported display height prior to any compatibility mode scaling
       * being applied.
       * @hide
       */
      @UnsupportedAppUsage
      public int noncompatHeightPixels;
      /**
       * The reported display density prior to any compatibility mode scaling
       * being applied.
       * @hide
       */
      public float noncompatDensity;
      /**
       * The reported display density prior to any compatibility mode scaling
       * being applied.
       * @hide
       */
      @UnsupportedAppUsage
      public int noncompatDensityDpi;
      /**
       * The reported scaled density prior to any compatibility mode scaling
       * being applied.
       * @hide
       */
      public float noncompatScaledDensity;
      /**
       * The reported display xdpi prior to any compatibility mode scaling
       * being applied.
       * @hide
       */
      public float noncompatXdpi;
      /**
       * The reported display ydpi prior to any compatibility mode scaling
       * being applied.
       * @hide
       */
      public float noncompatYdpi;
  
      public DisplayMetrics() {
      }
      
      public void setTo(DisplayMetrics o) {
          if (this == o) {
              return;
          }
  
          widthPixels = o.widthPixels;
          heightPixels = o.heightPixels;
          density = o.density;
          densityDpi = o.densityDpi;
          scaledDensity = o.scaledDensity;
          xdpi = o.xdpi;
          ydpi = o.ydpi;
          noncompatWidthPixels = o.noncompatWidthPixels;
          noncompatHeightPixels = o.noncompatHeightPixels;
          noncompatDensity = o.noncompatDensity;
          noncompatDensityDpi = o.noncompatDensityDpi;
          noncompatScaledDensity = o.noncompatScaledDensity;
          noncompatXdpi = o.noncompatXdpi;
          noncompatYdpi = o.noncompatYdpi;
      }
      
      public void setToDefaults() {
          widthPixels = 0;
          heightPixels = 0;
          density =  DENSITY_DEVICE / (float) DENSITY_DEFAULT;
          densityDpi =  DENSITY_DEVICE;
          scaledDensity = density;
          xdpi = DENSITY_DEVICE;
          ydpi = DENSITY_DEVICE;
          noncompatWidthPixels = widthPixels;
          noncompatHeightPixels = heightPixels;
          noncompatDensity = density;
          noncompatDensityDpi = densityDpi;
          noncompatScaledDensity = scaledDensity;
          noncompatXdpi = xdpi;
          noncompatYdpi = ydpi;
      }
  
      @Override
      public boolean equals(Object o) {
          return o instanceof DisplayMetrics && equals((DisplayMetrics)o);
      }
  
      /**
       * Returns true if these display metrics equal the other display metrics.
       *
       * @param other The display metrics with which to compare.
       * @return True if the display metrics are equal.
       */
      public boolean equals(DisplayMetrics other) {
          return equalsPhysical(other)
                  && scaledDensity == other.scaledDensity
                  && noncompatScaledDensity == other.noncompatScaledDensity;
      }
  
      /**
       * Returns true if the physical aspects of the two display metrics
       * are equal.  This ignores the scaled density, which is a logical
       * attribute based on the current desired font size.
       *
       * @param other The display metrics with which to compare.
       * @return True if the display metrics are equal.
       * @hide
       */
      public boolean equalsPhysical(DisplayMetrics other) {
          return other != null
                  && widthPixels == other.widthPixels
                  && heightPixels == other.heightPixels
                  && density == other.density
                  && densityDpi == other.densityDpi
                  && xdpi == other.xdpi
                  && ydpi == other.ydpi
                  && noncompatWidthPixels == other.noncompatWidthPixels
                  && noncompatHeightPixels == other.noncompatHeightPixels
                  && noncompatDensity == other.noncompatDensity
                  && noncompatDensityDpi == other.noncompatDensityDpi
                  && noncompatXdpi == other.noncompatXdpi
                  && noncompatYdpi == other.noncompatYdpi;
      }
  
      @Override
      public int hashCode() {
          return widthPixels * heightPixels * densityDpi;
      }
  
      @Override
      public String toString() {
          return "DisplayMetrics{density=" + density + ", width=" + widthPixels +
              ", height=" + heightPixels + ", scaledDensity=" + scaledDensity +
              ", xdpi=" + xdpi + ", ydpi=" + ydpi + "}";
      }
  
      private static int getDeviceDensity() {
          // qemu.sf.lcd_density can be used to override ro.sf.lcd_density
          // when running in the emulator, allowing for dynamic configurations.
          // The reason for this is that ro.sf.lcd_density is write-once and is
          // set by the init process when it parses build.prop before anything else.
          return SystemProperties.getInt("qemu.sf.lcd_density",
                  SystemProperties.getInt("ro.sf.lcd_density", DENSITY_DEFAULT));
      }
  }
  