Gnome::Pango::T-gravity

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Class initialization

new

Initialization of a type class is simple and only needed when the standalone functions are used.

method new ( )

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Enumerations

PangoGravity

enumeration PangoGravity defined in Gnome::Pango::T-gravity represents the orientation of glyphs in a segment of text.

This is useful when rendering vertical text layouts. In those situations, the layout is rotated using a non-identity Gnome::Pango::N-Matrix , and then glyph orientation is controlled using enumeration PangoGravity defined in Gnome::Pango::T-gravity.

Not every value in this enumeration makes sense for every usage of enumeration PangoGravity defined in Gnome::Pango::T-gravity; for example, PANGO_GRAVITY_AUTO only can be passed to .set-base-gravity() in class Gnome::Pango::Context and can only be returned by .get-base-gravity() in class Gnome::Pango::Context.

See also: enumeration GravityHint from Gnome::Pango::T-gravity

• PANGO_GRAVITY_SOUTH; Glyphs stand upright (default) <img align="right" valign="center" src="m-south.png">

• PANGO_GRAVITY_EAST; Glyphs are rotated 90 degrees counter-clockwise. <img align="right" valign="center" src="m-east.png">

• PANGO_GRAVITY_NORTH; Glyphs are upside-down. <img align="right" valign="cener" src="m-north.png">

• PANGO_GRAVITY_WEST; Glyphs are rotated 90 degrees clockwise. <img align="right" valign="center" src="m-west.png">

• PANGO_GRAVITY_AUTO; Gravity is resolved from the context matrix

PangoGravityHint

enumeration PangoGravityHint defined in Gnome::Pango::T-gravity defines how horizontal scripts should behave in a vertical context.

That is, English excerpts in a vertical paragraph for example.

See also enumeration Gravity from Gnome::Pango::T-gravity

• PANGO_GRAVITY_HINT_NATURAL; scripts will take their natural gravity based on the base gravity and the script. This is the default.

• PANGO_GRAVITY_HINT_STRONG; always use the base gravity set, regardless of the script.

• PANGO_GRAVITY_HINT_LINE; for scripts not in their natural direction (eg. Latin in East gravity), choose per-script gravity such that every script respects the line progression. This means, Latin and Arabic will take opposite gravities and both flow top-to-bottom for example.

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Standalone Functions

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gravity-get-for-matrix This function is not yet available

Finds the gravity that best matches the rotation component in a Gnome::Pango::N-Matrix.

method gravity-get-for-matrix ( CArray[N-Matrix]  $matrix --> PangoGravity )

• $matrix; a Gnome::Pango::N-Matrix.

Return value; the gravity of $matrix, which will never be PANGO_GRAVITY_AUTO, or PANGO_GRAVITY_SOUTH if $matrix is undefined.

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gravity-get-for-script This function is not yet available

Returns the gravity to use in laying out a Gnome::Pango::N-Item.

The gravity is determined based on the script, base gravity, and hint.

If $base_gravity is PANGO_GRAVITY_AUTO, it is first replaced with the preferred gravity of $script. To get the preferred gravity of a script, pass PANGO_GRAVITY_AUTO and PANGO_GRAVITY_HINT_STRONG in.

method gravity-get-for-script ( PangoScript  $script, PangoGravity $base-gravity, PangoGravityHint $hint --> PangoGravity )

• $script; enumeration PangoScript defined in Gnome::Pango::T-ScriptIter to query.

• $base-gravity; base gravity of the paragraph.

• $hint; orientation hint.

Return value; resolved gravity suitable to use for a run of text with $script.

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gravity-get-for-script-and-width This function is not yet available

Returns the gravity to use in laying out a single character or Gnome::Pango::N-Item.

The gravity is determined based on the script, East Asian width, base gravity, and hint,

This function is similar to .Gravity.get-for-script() except that this function makes a distinction between narrow/half-width and wide/full-width characters also. Wide/full-width characters always stand *upright*, that is, they always take the base gravity, whereas narrow/full-width characters are always rotated in vertical context.

If $base_gravity is PANGO_GRAVITY_AUTO, it is first replaced with the preferred gravity of $script.

method gravity-get-for-script-and-width ( PangoScript  $script, Bool() $wide, PangoGravity $base-gravity, PangoGravityHint $hint --> PangoGravity )

• $script; enumeration PangoScript defined in Gnome::Pango::T-ScriptIter to query.

• $wide; True for wide characters as returned by g_unichar_iswide().

• $base-gravity; base gravity of the paragraph.

• $hint; orientation hint.

Return value; resolved gravity suitable to use for a run of text with $script and $wide..

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gravity-to-rotation

Converts a enumeration PangoGravity defined in Gnome::Pango::T-gravity value to its natural rotation in radians.

Note that .rotate() in class Gnome::Pango::N-Matrix takes angle in degrees, not radians. So, to call [method $Pango.Matrix,rotate] with the output of this function you should multiply it by (180. / G_PI).

method gravity-to-rotation ( PangoGravity $gravity --> Num )

• $gravity; gravity to query, should not be PANGO_GRAVITY_AUTO.

Return value; the rotation value corresponding to $gravity..