android.util.DisplayMetrics#DENSITY_DEVICE_STABLE源码实例Demo

/**
 * Returns context with default screen densityDpi.This context is used to keep the layout size as
 * per the default screen densityDpi and not based on the display size setting changed by the
 * user.
 */
public static Context getDefaultScreenDensityContext(Context context) {
  Resources res = context.getResources();
  Configuration configuration = new Configuration(res.getConfiguration());

  /* get default display density */
  if (BuildVersionUtils.isAtLeastN()) {
    configuration.densityDpi = DisplayMetrics.DENSITY_DEVICE_STABLE;
  } else {
    WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
    DisplayMetrics dm = new DisplayMetrics();
    wm.getDefaultDisplay().getRealMetrics(dm);
    configuration.densityDpi = dm.densityDpi;
  }
  configuration.setTo(configuration);

  return context.createConfigurationContext(configuration);
}
 

/**
 * Shows the "unsupported display size" warning, if necessary.
 *
 * @param r activity record for which the warning may be displayed
 */
public void showUnsupportedDisplaySizeDialogIfNeeded(ActivityRecord r) {
    final Configuration globalConfig = mAms.getGlobalConfiguration();
    if (globalConfig.densityDpi != DisplayMetrics.DENSITY_DEVICE_STABLE
            && r.appInfo.requiresSmallestWidthDp > globalConfig.smallestScreenWidthDp) {
        mUiHandler.showUnsupportedDisplaySizeDialog(r);
    }
}
 

static boolean getAllowRotationDefaultValue(Context context) {
    if (AndroidVersion.isAtLeastNougat) {
        // If the device was scaled, used the original dimensions to determine if rotation
        // is allowed of not.
        Resources res = context.getResources();
        int originalSmallestWidth = res.getConfiguration().smallestScreenWidthDp
                * res.getDisplayMetrics().densityDpi / DisplayMetrics.DENSITY_DEVICE_STABLE;
        return originalSmallestWidth >= 600;
    }
    return false;
}