R/pangoManuals.R

Defines functions checkPango boundPangoVersion pangoReorderItems pangoRbearing pangoLbearing pangoDescent pangoAscent pangoTabArrayNewWithPositions pangoShape pangoGlyphStringXToIndex pangoGlyphStringIndexToX pangoParseMarkup pangoLayoutSetMarkupWithAccel pangoMatrixInit pangoBreak pangoGlyphStringGetLogicalWidths pangoGetLogAttrs

Documented in boundPangoVersion checkPango pangoAscent pangoBreak pangoDescent pangoGetLogAttrs pangoGlyphStringGetLogicalWidths pangoGlyphStringIndexToX pangoGlyphStringXToIndex pangoLayoutSetMarkupWithAccel pangoLbearing pangoMatrixInit pangoParseMarkup pangoRbearing pangoReorderItems pangoShape pangoTabArrayNewWithPositions

# reason: we need to hide the text length parameter
pangoGetLogAttrs <-
function(text, level, language)
{
        text <- as.character(text)
        level <- as.integer(level)
        checkPtrType(language, "PangoLanguage")

        w <- .RGtkCall("S_pango_get_log_attrs", text, level, language)

        return(invisible(w))
}
pangoGlyphStringGetLogicalWidths <-
function(object, text, embedding.level)
{
        checkPtrType(object, "PangoGlyphString")
        text <- as.character(text)
        embedding.level <- as.integer(embedding.level)

        w <- .RGtkCall("S_pango_glyph_string_get_logical_widths", object, text, embedding.level)

        return(w)
}

# reason: removed text length and attrs length parameters
pangoBreak <-
function(text, analysis)
{
        text <- as.character(text)
        checkPtrType(analysis, "PangoAnalysis")

        w <- .RGtkCall("S_pango_break", text, analysis)

        return(invisible(w))
}

# reason: PangoMatrix is a boxed type that needs to be treated as a reference,
# but there is no way to create one from an API function
# This mimics the aliased static initializer in the API.

pangoMatrixInit <-
function()
{
	w <- .RGtkCall("S_pango_matrix_init")
	
	return(w)
}

# Here are some Pango constants
PANGO_SCALE <- 1024
PANGO_SCALE_XX_SMALL <-  (1 / (1.2 * 1.2 * 1.2))
PANGO_SCALE_X_SMALL <- (1 / (1.2 * 1.2))
PANGO_SCALE_SMALL <- (1 / 1.2)
PANGO_SCALE_MEDIUM <- 1
PANGO_SCALE_LARGE <- 1 * 1.2
PANGO_SCALE_X_LARGE <- 1 * 1.2 * 1.2
PANGO_SCALE_XX_LARGE <- 1 * 1.2 * 1.2 * 1.2

# reason: now let's handle the functions where the text length is omitted
pangoLayoutSetMarkupWithAccel <-
function(object, markup, accel.marker)
{
        checkPtrType(object, "PangoLayout")
        markup <- as.character(markup)
        length <- -1
        accel.marker <- as.character(accel.marker)

        w <- .RGtkCall("S_pango_layout_set_markup_with_accel", object, markup, length, accel.marker)

        return(w)
}
pangoParseMarkup <-
function(markup.text, accel.marker, .errwarn = TRUE)
{
        markup.text <- as.character(markup.text)
        length <- -1
        accel.marker <- as.character(accel.marker)

        w <- .RGtkCall("S_pango_parse_markup", markup.text, length, accel.marker)

        w <- handleError(w, .errwarn)
        
        return(w)
}
pangoGlyphStringIndexToX <-
function(object, text, analysis, index, trailing)
{
        checkPtrType(object, "PangoGlyphString")
        text <- as.character(text)
        length <- nchar(text)
        checkPtrType(analysis, "PangoAnalysis")
        index <- as.integer(index)
        trailing <- as.logical(trailing)

        w <- .RGtkCall("S_pango_glyph_string_index_to_x", object, text, length, analysis, index, trailing)

        return(w)
}
pangoGlyphStringXToIndex <-
function(object, text, analysis, x.pos)
{
        checkPtrType(object, "PangoGlyphString")
        text <- as.character(text)
        length <- nchar(text)
        checkPtrType(analysis, "PangoAnalysis")
        x.pos <- as.integer(x.pos)

        w <- .RGtkCall("S_pango_glyph_string_x_to_index", object, text, length, analysis, x.pos)

        return(invisible(w))
}
pangoShape <-
function(text, analysis, glyphs)
{
        text <- as.character(text)
        length <- nchar(text)
        checkPtrType(analysis, "PangoAnalysis")
        checkPtrType(glyphs, "PangoGlyphString")

        w <- .RGtkCall("S_pango_shape", text, length, analysis, glyphs)

        return(w)
}
# reason: var-args, just set aligns/positions for each one
pangoTabArrayNewWithPositions <-
function(size, positions.in.pixels, ...)
{
        size <- as.integer(size)
        positions.in.pixels <- as.logical(positions.in.pixels)
        args <- list(...)
		alignments <- args[seq(1,length(args),by=2)]
		positions <- args[seq(2,length(args),by=2)]
		
		array <- pangoTabArrayNew(size, positions.in.pixels)
		for (i in 1:length(args))
			pangoTabArraySetTab(array, i-1, alignments[[i]], positions[[i]])
        
		return(array)
}

# these are macros that seem simple enough to reimplement in R
# of course, if they change this will also need to be updated

pangoAscent <- function(x)
{
	rect <- as.PangoRectangle(x)
	-rect$y
}
pangoDescent <- function(x)
{
	rect <- as.PangoRectangle(x)
	rect$y + rect$height
}
pangoLbearing <- function(x)
{
	rect <- as.PangoRectangle(x)
	rect$x
}
pangoRbearing <- function(x)
{
	rect <- as.PangoRectangle(x)
	rect$x + rect$width
}

pangoReorderItems <-
function(logical.items)
{
	.notimplemented("wouldn't work automatically due to memory management details and the API says its useless")
}

## version checking ##

boundPangoVersion <- function() {
  as.numeric_version(paste(.RGtkCall("boundPangoVersion"), collapse="."))
}

checkPango <- function(version) {
  .Deprecated("boundPangoVersion() >= version")
  boundPangoVersion() >= version
}

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RGtk2 documentation built on Jan. 26, 2018, 1:32 a.m.