GenValue: 4.6 Supplemental Usage: Using Ranges in GenValues

HINT_VALUE_DISPLAYS_RANGE, MSG_GEN_VALUE_SET_RANGE_LENGTH, MSG_GEN_VALUE_GET_RANGE_LENGTH, MSG_GEN_VALUE_ADD_RANGE_LENGTH, MSG_GEN_VALUE_SUBTRACT_RANGE_LENGTH

Special GenValue objects may actually display ranges rather than individual values within a range--for example, the GEOS scrollbars in OSF/Motif display the percentage of the document visible in the view.

For your GenValue to display a range, use HINT_VALUE_DISPLAYS_RANGE . If this hint is not present, the GenValue is assumed to have a range size of zero. This hint takes an argument of WWFixedAsDWord to indicate the size of the range.

To get the range length, use MSG_GEN_VALUE_GET_RANGE_LENGTH . To set the range, use MSG_GEN_VALUE_SET_RANGE_LENGTH . Two other messages, MSG_GEN_VALUE_ADD_RANGE_LENGTH and MSG_GEN_VALUE_SUBTRACT_RANGE_LENGTH , add or subtract the value of the GenValue by the range length.

MSG_GEN_VALUE_GET_RANGE_LENGTH

WWFixedAsDWord MSG_GEN_VALUE_GET_RANGE_LENGTH();

This message returns the value stored in HINT_VALUE_DISPLAYS_RANGE .

Source: Unrestricted.

Destination: Any GenValue object.

Parameters: None.

Return: The value stored in HINT_VALUE_DISPLAYS_RANGE . If this hint is not set, the return value will be zero.

Interception: Generally not intercepted.

MSG_GEN_VALUE_SET_RANGE_LENGTH

void	MSG_GEN_VALUE_SET_RANGE_LENGTH(
        WWFixedAsDWord value);

This message has the effect of adding or changing the hint HINT_VALUE_DISPLAYS_RANGE for the GenValue. Setting a value of zero will cause the GenValue to act as if it did not have this hint.

Source: Unrestricted.

Destination: Any GenValue object.

Parameters: value The new range length.

Return: Nothing.

Interception: Generally not intercepted.

MSG_GEN_VALUE_ADD_RANGE_LENGTH

void	MSG_GEN_VALUE_ADD_RANGE_LENGTH();

This message adds the range length to the current value of the GenValue object. It has the effect of incrementing the GVLI_value field by the range length.

Source: Unrestricted.

Destination: Any GenValue object.

Interception: Generally not intercepted.

MSG_GEN_VALUE_SUBTRACT_RANGE_LENGTH

void	MSG_GEN_VALUE_SUBTRACT_RANGE_LENGTH();

This message subtracts the range length from the current value of the GenValue object. It has the effect of decrementing the GVLI_value field by the range length.

Source: Unrestricted.

Destination: Any GenValue object.

Interception: Generally not intercepted.

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4.5 Text Filters for the GenValue