ArithmeticExpression

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A collection of arithmetic functions and operations, which other Watch Face Format elements use to resolve real-time attribute values and gyroscopic effects.

Introduced in Wear OS 4.

Example

An example expression for rotating a value up to 5 degrees in either direction, based on the $ x $-value of the Wear OS device's accelerometer:

(5/90)*clamp([ACCELEROMETER_ANGLE_X],0,90) + (-5/90)*clamp([ACCELEROMETER_ANGLE_X],-90,0)

...which is equivalent to the following mathematical expression, where $ \theta_x $ represents the accelerometer angle in the $ x $-direction:

Functions

The Watch Face Format recognizes the following string values as functions:

Operators

The Watch Face Format recognizes the following string values as operators:

+

Unary plus, or addition of multiple values. Supports both integers and floating-point values.

-

Unary minus, or subtraction of multiple values. Supports both integers and floating-point values.

*

Multiplication of multiple integer or floating-point values.

/

Division of 2 integer or floating-point values.

If division of 2 integers results in a non-integer value, the decimal part is preserved in the floating-point result. For example, $ \frac{1}{2} = 0.5 $.

In addition, the expression $ \frac{x}{0} $ is evaluated as 0, where $ x $ is any integer.

%

Modular division of 2 integer or floating-point values.

If both operands are integers, the result is the remainder from dividing the 2 values. For example, $ 19 \bmod 7 = 5 $.

If at least one operand is a floating-point number, the result is a floating-point equivalent of the remainder; for example: $ 19.0 \bmod 7 = 5.0 $.

~

Bitwise "not" operator. Several examples:

• ~1 is $ -2 $
• ~0 is $ -1 $

!

Logical "not" operator, which supports double negatives. Several examples:

• $ !2 $ is false
• $ !!0 $ is true

|

Bitwise "or" operator. Supports more than 2 input values. Several examples:

• $ 1 | 0 = 1 $
• $ 1 | 2 | 4 = 7 $

||

Logical "or" operator.

&

Bitwise "and" operator. Supports exactly 2 input values.

&&

Logical "and" operator.

(

Open parenthesis. Used for changing the standard order of operations, where multiplication and division ordinarily take priority over addition and subtraction.

)

Closed parenthesis. Used for changing the standard order of operations, where multiplication and division ordinarily take priority over addition and subtraction.

<

The "less than" comparison operator. When comparing an integer value with its floating-point equivalent, the result is false.

<=

The "less than or equal to" comparison operator. When comparing an integer value with its floating-point equivalent, the result is true.

>

The "greater than" comparison operator. When comparing an integer value with its floating-point equivalent, the result is false.

>=

The "greater than or equal to" comparison operator. When comparing an integer value with its floating-point equivalent, the result is true.

? and :

Provides support for ternary operations. The general format is as follows:

condition ? value_if_true : value_if_false

Supports nested ternary operations using parentheses.

,

Separates values in functions that take more than 1 argument.

"

When placed at the beginning and end of a value, indicates that the Watch Face Format should interpret the value as a string.

==

Compare for equality. When comparing an integer value with its floating-point equivalent, the result is true.

!=

Compare for inequality. When comparing an integer value with its floating-point equivalent, the result is false.