12.6.10 Anchor Flow Object Class

Use of this flow object requires the page feature.

An anchor flow object is atomic and serves only as a flow object to be synchronized. It may be either inlined or displayed. If inlined, it produces a single area with zero size in the escapement direction. If displayed, it produces a single area with zero size in the placement direction. The resulting area will be kept with the first area resulting from the flow object that follows unless the anchor-keep-with-previous?: characteristic is true.

Anchor flow objects have the following characteristics:

• anchor-keep-with-previous?: is a boolean specifying whether the resulting area shall be kept with the last area of the previous flow object instead of the first area resulting from the following flow object. The initial value is #f.

• display?: is a boolean specifying whether the flow object is displayed rather than inlined. This characteristic is not inherited. The default value is #f.

• span: is a strictly positive integer specifying the number of columns that the areas resulting from this flow object shall span. This characteristic shall apply if the flow object is directed into a port on a column-set-sequence flow object that is flowed into the top-float, bottom-float, or body-text zone of a spannable column-subset. The initial value is 1.

• span-weak?: is a boolean specifying whether the areas resulting from this flow object span weakly rather than strongly. See section 12.6.5.1, Column-set-model. This characteristic applies if the flow object is directed into a port on a column-set-sequence flow object that is flowed into the top-float, bottom-float, or body-text zone of a spannable column-subset and has a span: characteristic with a value greater than 1. The initial value is #f.

• inhibit-line-breaks?: is a boolean specifying whether line breaks shall be inhibited before and after each area produced by this flow object. This applies only to line breaks introduced by the formatter to make lines fit in the available space. The initial value is #f.

• break-before-priority: is an integer that affects whether a break is allowed before this flow object. The break priority of a potential breakpoint is the maximum of the break-after-priority of the flow object immediately preceding the potential breakpoint and the break-before-priorities of the flow object immediately following the potential breakpoint, and any characters immediately following that character for which the drop-after-line-break?: characteristic is true. A break shall be allowed at a potential breakpoint only if the break priority is even. This characteristic is not inherited. The default value is 0.

• break-after-priority: is an integer that affects whether a break is allowed after this flow object as described in the specification of the break-before-priority: characteristic. This characteristic is not inherited. The default value is 0.