Package google.type

Index

Color

Represents a color in the RGBA color space. This representation is designed for simplicity of conversion to/from color representations in various languages over compactness; for example, the fields of this representation can be trivially provided to the constructor of "java.awt.Color" in Java; it can also be trivially provided to UIColor's "+colorWithRed:green:blue:alpha" method in iOS; and, with just a little work, it can be easily formatted into a CSS "rgba()" string in JavaScript, as well. Here are some examples:

Example (Java):

 import com.google.type.Color;

 // ...
 public static java.awt.Color fromProto(Color protocolor) {
   float alpha = protocolor.hasAlpha()
       ? protocolor.getAlpha().getValue()
       : 1.0;

   return new java.awt.Color(
       protocolor.getRed(),
       protocolor.getGreen(),
       protocolor.getBlue(),
       alpha);
 }

 public static Color toProto(java.awt.Color color) {
   float red = (float) color.getRed();
   float green = (float) color.getGreen();
   float blue = (float) color.getBlue();
   float denominator = 255.0;
   Color.Builder resultBuilder =
       Color
           .newBuilder()
           .setRed(red / denominator)
           .setGreen(green / denominator)
           .setBlue(blue / denominator);
   int alpha = color.getAlpha();
   if (alpha != 255) {
     result.setAlpha(
         FloatValue
             .newBuilder()
             .setValue(((float) alpha) / denominator)
             .build());
   }
   return resultBuilder.build();
 }
 // ...

Example (iOS / Obj-C):

 // ...
 static UIColor* fromProto(Color* protocolor) {
    float red = [protocolor red];
    float green = [protocolor green];
    float blue = [protocolor blue];
    FloatValue* alpha_wrapper = [protocolor alpha];
    float alpha = 1.0;
    if (alpha_wrapper != nil) {
      alpha = [alpha_wrapper value];
    }
    return [UIColor colorWithRed:red green:green blue:blue alpha:alpha];
 }

 static Color* toProto(UIColor* color) {
     CGFloat red, green, blue, alpha;
     if (![color getRed:&red green:&green blue:&blue alpha:&alpha]) {
       return nil;
     }
     Color* result = [Color alloc] init];
     [result setRed:red];
     [result setGreen:green];
     [result setBlue:blue];
     if (alpha <= 0.9999) {
       [result setAlpha:floatWrapperWithValue(alpha)];
     }
     [result autorelease];
     return result;
}
// ...

Example (JavaScript):

// ...

var protoToCssColor = function(rgb_color) {
   var redFrac = rgb_color.red || 0.0;
   var greenFrac = rgb_color.green || 0.0;
   var blueFrac = rgb_color.blue || 0.0;
   var red = Math.floor(redFrac * 255);
   var green = Math.floor(greenFrac * 255);
   var blue = Math.floor(blueFrac * 255);

   if (!('alpha' in rgb_color)) {
      return rgbToCssColor_(red, green, blue);
   }

   var alphaFrac = rgb_color.alpha.value || 0.0;
   var rgbParams = [red, green, blue].join(',');
   return ['rgba(', rgbParams, ',', alphaFrac, ')'].join('');
};

var rgbToCssColor_ = function(red, green, blue) {
  var rgbNumber = new Number((red << 16) | (green << 8) | blue);
  var hexString = rgbNumber.toString(16);
  var missingZeros = 6 - hexString.length;
  var resultBuilder = ['#'];
  for (var i = 0; i < missingZeros; i++) {
     resultBuilder.push('0');
  }
  resultBuilder.push(hexString);
  return resultBuilder.join('');
};

// ...
Fields
red

float

The amount of red in the color as a value in the interval [0, 1].

green

float

The amount of green in the color as a value in the interval [0, 1].

blue

float

The amount of blue in the color as a value in the interval [0, 1].

alpha

FloatValue

The fraction of this color that should be applied to the pixel. That is, the final pixel color is defined by the equation:

pixel color = alpha * (this color) + (1.0 - alpha) * (background color)

This means that a value of 1.0 corresponds to a solid color, whereas a value of 0.0 corresponds to a completely transparent color. This uses a wrapper message rather than a simple float scalar so that it is possible to distinguish between a default value and the value being unset. If omitted, this color object is to be rendered as a solid color (as if the alpha value had been explicitly given with a value of 1.0).

LatLng

An object representing a latitude/longitude pair. This is expressed as a pair of doubles representing degrees latitude and degrees longitude. Unless specified otherwise, this must conform to the WGS84 standard. Values must be within normalized ranges.

Example of normalization code in Python:

def NormalizeLongitude(longitude):
  """Wraps decimal degrees longitude to [-180.0, 180.0]."""
  q, r = divmod(longitude, 360.0)
  if r > 180.0 or (r == 180.0 and q <= -1.0):
    return r - 360.0
  return r

def NormalizeLatLng(latitude, longitude):
  """Wraps decimal degrees latitude and longitude to
  [-90.0, 90.0] and [-180.0, 180.0], respectively."""
  r = latitude % 360.0
  if r <= 90.0:
    return r, NormalizeLongitude(longitude)
  elif r >= 270.0:
    return r - 360, NormalizeLongitude(longitude)
  else:
    return 180 - r, NormalizeLongitude(longitude + 180.0)

assert 180.0 == NormalizeLongitude(180.0)
assert -180.0 == NormalizeLongitude(-180.0)
assert -179.0 == NormalizeLongitude(181.0)
assert (0.0, 0.0) == NormalizeLatLng(360.0, 0.0)
assert (0.0, 0.0) == NormalizeLatLng(-360.0, 0.0)
assert (85.0, 180.0) == NormalizeLatLng(95.0, 0.0)
assert (-85.0, -170.0) == NormalizeLatLng(-95.0, 10.0)
assert (90.0, 10.0) == NormalizeLatLng(90.0, 10.0)
assert (-90.0, -10.0) == NormalizeLatLng(-90.0, -10.0)
assert (0.0, -170.0) == NormalizeLatLng(-180.0, 10.0)
assert (0.0, -170.0) == NormalizeLatLng(180.0, 10.0)
assert (-90.0, 10.0) == NormalizeLatLng(270.0, 10.0)
assert (90.0, 10.0) == NormalizeLatLng(-270.0, 10.0)
Fields
latitude

double

The latitude in degrees. It must be in the range [-90.0, +90.0].

longitude

double

The longitude in degrees. It must be in the range [-180.0, +180.0].

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