/ 
Term-Fabulous-0.01
/ Term::Fabulous::Render::Border

NAME

Term::Fabulous::Render::Border - Paint widget borders in their border styles

SYNOPSIS

# Composed by Term::Fabulous::Render; called from draw for every
# border render command:
$ui->render_border( $command, $widget, $buffer );

DESCRIPTION

Most programs never use this module directly, and neither do widgets of your own: a widget gets its border from the parameters described in "BORDERS" in Term::Fabulous::Manual::Looks. This module is one of the roles Term::Fabulous::Render is made of, and it paints the border render commands Clay emits for widgets with a border (see "bordered" in Term::Fabulous::Widget), using the widget's border styles (see Term::Fabulous::Role::HasBorderStyle and Term::Fabulous::Enum::BorderStyle).

METHODS

render_border

$ui->render_border( $command, $widget, $buffer );

Paints the border of $widget:

  • Nothing is painted unless $widget composes Term::Fabulous::Role::HasBorderStyle.

  • A side is painted when its width in the command is positive: Term::Fabulous::Role::HasBorderStyle gives every side with a border the width 1. A side is one cell thick: it is drawn on the outermost row or column of the widget's box. Corners are drawn where a painted top or bottom side meets a painted left or right side; otherwise the top or bottom edge glyph continues to the end of the row. In a box only one cell high, the top and bottom sides would share the same row: when both are to be drawn, only the top side is. Likewise in a box one cell wide only the left side is drawn when both the left and the right side are to be drawn. A side with the Hidden style arrives with a width of 0 (see Term::Fabulous::Role::HasBorderStyle), so it is not painted and the neighboring sides treat it like a side without a width.

  • Each side uses the style it is drawn in, as "border_style_of" in Term::Fabulous::Role::HasBorderStyle answers: the widget's own style for that side, else the one the widget derives, else the theme's style for the widget's family, else the Blank style (spaces). A corner the widget names in border_corners is drawn with that glyph instead (see "border_corners" in Term::Fabulous::Role::HasBorderStyle), in the colors of the style's corner.

  • Each glyph is colored according to its style's location code (see "locations" in Term::Fabulous::Enum::BorderStyle): the border color in front of either the widget's own background (the background already painted in that cell, read from $buffer) or the parent's background (the background of the cell just outside the box, also read from $buffer), possibly in reverse video.

  • A side the widget lists in outer_border_sides (see "outer_border_sides" in Term::Fabulous::Role::HasBorderStyle) is drawn on the parent's background: its glyphs with location code 0 are drawn as code 1, those with code 3 as code 2, and codes 1 and 2 stay. A corner is drawn this way, with the background of the cell beside the box, when the left or right side next to it is listed; otherwise it follows its top or bottom side.

  • Only cells inside the current clip area are painted.

$command is a Clay render command hash (see "RENDER COMMANDS" in Clay::XS); $buffer is the array reference of rows of background attributes, $buffer->[$y][$x], that Term::Fabulous::Render::Rectangle and the other paint roles fill during the frame.

REQUIRED METHODS

The consuming class provides cell_target, which returns the cell target the border is painted into (its set_cell is called; see "CELL TARGET" in Term::Fabulous::Render), and clip_rect (from Term::Fabulous::Render, see "clip_rect" in Term::Fabulous::Render).

SEE ALSO

Term::Fabulous::Render, Term::Fabulous::Enum::BorderStyle, Term::Fabulous::Role::HasBorderStyle, "BORDERS" in Term::Fabulous::Manual::Looks.