Class: Pango::Layout

Inherits:
Object
  • Object
show all
Defined in:
(unknown)

Instance Method Summary collapse

Instance Method Details

#alignmentPango::Alignment

Gets the alignment for the layout: how partial lines are positioned within the horizontal space available.

Returns:

#alignment=(alignment) ⇒ nil

Sets the alignment for the layout: how partial lines are positioned within the horizontal space available.

Parameters:

Returns:

  • (nil)

#attributesPango::AttrList

Gets the attribute list for the layout, if any.

Returns:

  • (Pango::AttrList)

    a Pango::AttrList.

#attributes=(attrs) ⇒ nil

Sets the text attributes for a layout object. References attrs, so the caller can unref its reference.

Parameters:

  • attrs (Pango::AttrList)

    a Pango::AttrList, can be nil

Returns:

  • (nil)

#auto_dirTrueClass

Gets whether to calculate the bidirectional base direction for the layout according to the contents of the layout. See pango_layout_set_auto_dir().

Returns:

  • (TrueClass)

    true if the bidirectional base direction is computed from the layout’s contents, false otherwise.

#auto_dir=(auto_dir) ⇒ nil

Sets whether to calculate the bidirectional base direction for the layout according to the contents of the layout; when this flag is on (the default), then paragraphs in

<b>layout</b> that begin with strong right-to-left characters

(Arabic and Hebrew principally), will have right-to-left layout, paragraphs with letters from other scripts will have left-to-right layout. Paragraphs with only neutral characters get their direction from the surrounding paragraphs.

When false, the choice between left-to-right and right-to-left layout is done according to the base direction of the layout’s Pango::Context. (See pango_context_set_base_dir()).

When the auto-computed direction of a paragraph differs from the base direction of the context, the interpretation of %PANGO_ALIGN_LEFT and %PANGO_ALIGN_RIGHT are swapped.

Parameters:

  • auto_dir (TrueClass)

    if true, compute the bidirectional base direction from the layout’s contents.

Returns:

  • (nil)

#baselineInteger

Gets the Y position of baseline of the first line in layout.

Returns:

  • (Integer)

    baseline of first line, from top of layout.

#character_countInteger

Returns the number of Unicode characters in the the text of layout.

Returns:

  • (Integer)

    the number of Unicode characters in the text of layout

#contextPango::Context

Retrieves the Pango::Context used for this layout. This does not have an additional refcount added, so if you want to keep a copy of this around, you must reference it yourself.

Returns:

#context_changednil

Forces recomputation of any state in the Pango::Layout that might depend on the layout’s context. This function should be called if you make changes to the context subsequent to creating the layout.

Returns:

  • (nil)

#copyPango::Layout

Does a deep copy-by-value of the src layout. The attribute list, tab array, and text from the original layout are all copied by value.

Returns:

  • (Pango::Layout)

    the newly allocated Pango::Layout, with a reference count of one, which should be freed with g_object_unref().

#ellipsizePango::EllipsizeMode

Gets the type of ellipsization being performed for layout. See pango_layout_set_ellipsize() Use pango_layout_is_ellipsized() to query whether any paragraphs were actually ellipsized.

Returns:

#ellipsize=(ellipsize) ⇒ nil

Sets the type of ellipsization being performed for layout. Depending on the ellipsization mode ellipsize text is removed from the start, middle, or end of text so they fit within the width and height of layout set with pango_layout_set_width() and pango_layout_set_height().

If the layout contains characters such as newlines that force it to be layed out in multiple paragraphs, then whether each paragraph is ellipsized separately or the entire layout is ellipsized as a whole depends on the set height of the layout. See pango_layout_set_height() for details.

Parameters:

Returns:

  • (nil)

#font_descriptionPango::FontDescription

Gets the font description for the layout, if any.

Returns:

  • (Pango::FontDescription)

    a pointer to the layout’s font description, or nil if the font description from the layout’s context is inherited. This value is owned by the layout and must not be modified or freed.

#font_description=(desc) ⇒ nil

Sets the default font description for the layout. If no font description is set on the layout, the font description from the layout’s context is used.

Parameters:

  • desc (Pango::FontDescription)

    the new Pango::FontDescription, or nil to unset the current font description

Returns:

  • (nil)

#get_cursor_pos(index_, strong_pos, weak_pos) ⇒ nil

Given an index within a layout, determines the positions that of the strong and weak cursors if the insertion point is at that index. The position of each cursor is stored as a zero-width rectangle. The strong cursor location is the location where characters of the directionality equal to the base direction of the layout are inserted. The weak cursor location is the location where characters of the directionality opposite to the base direction of the layout are inserted.

Parameters:

  • index_ (Integer)

    the byte index of the cursor

  • strong_pos (Pango::Rectangle)

    location to store the strong cursor position (may be nil)

  • weak_pos (Pango::Rectangle)

    location to store the weak cursor position (may be nil)

Returns:

  • (nil)

#get_extents(ink_rect, logical_rect) ⇒ nil

Computes the logical and ink extents of layout. Logical extents are usually what you want for positioning things. Note that both extents may have non-zero x and y. You may want to use those to offset where you render the layout. Not doing that is a very typical bug that shows up as right-to-left layouts not being correctly positioned in a layout with a set width.

The extents are given in layout coordinates and in Pango units; layout coordinates begin at the top left corner of the layout.

Parameters:

  • ink_rect (Pango::Rectangle)

    rectangle used to store the extents of the layout as drawn or nil to indicate that the result is not needed.

  • logical_rect (Pango::Rectangle)

    rectangle used to store the logical extents of the layout or nil to indicate that the result is not needed.

Returns:

  • (nil)

#get_line(line) ⇒ Pango::LayoutLine

Retrieves a particular line from a Pango::Layout.

Use the faster pango_layout_get_line_readonly() if you do not plan to modify the contents of the line (glyphs, glyph widths, etc.).

Parameters:

  • line (Integer)

    the index of a line, which must be between 0 and <literal>pango_layout_get_line_count(layout) - 1</literal>, inclusive.

Returns:

  • (Pango::LayoutLine)

    the requested Pango::LayoutLine, or nil if the index is out of range. This layout line can be ref’ed and retained, but will become invalid if changes are made to the Pango::Layout.

#get_line_readonly(line) ⇒ Pango::LayoutLine

Retrieves a particular line from a Pango::Layout.

This is a faster alternative to pango_layout_get_line(), but the user is not expected to modify the contents of the line (glyphs, glyph widths, etc.).

Parameters:

  • line (Integer)

    the index of a line, which must be between 0 and <literal>pango_layout_get_line_count(layout) - 1</literal>, inclusive.

Returns:

  • (Pango::LayoutLine)

    the requested Pango::LayoutLine, or nil if the index is out of range. This layout line can be ref’ed and retained, but will become invalid if changes are made to the Pango::Layout. No changes should be made to the line.

#get_log_attrs(attrs, n_attrs) ⇒ nil

Retrieves an array of logical attributes for each character in the layout.

Parameters:

  • attrs (Array<Pango::LogAttr>)

    location to store a pointer to an array of logical attributes This value must be freed with g_free().

  • n_attrs (Integer)

    location to store the number of the attributes in the array. (The stored value will be one more than the total number of characters in the layout, since there need to be attributes corresponding to both the position before the first character and the position after the last character.)

Returns:

  • (nil)

#get_log_attrs_readonly(n_attrs) ⇒ Array<Pango::LogAttr>

Retrieves an array of logical attributes for each character in the layout.

This is a faster alternative to pango_layout_get_log_attrs(). The returned array is part of layout and must not be modified. Modifying the layout will invalidate the returned array.

The number of attributes returned in n_attrs will be one more than the total number of characters in the layout, since there need to be attributes corresponding to both the position before the first character and the position after the last character.

Parameters:

  • n_attrs (Integer)

    location to store the number of the attributes in the array

Returns:

  • (Array<Pango::LogAttr>)

    an array of logical attributes

#get_pixel_extents(ink_rect, logical_rect) ⇒ nil

Computes the logical and ink extents of layout in device units. This function just calls pango_layout_get_extents() followed by two pango_extents_to_pixels() calls, rounding ink_rect and logical_rect such that the rounded rectangles fully contain the unrounded one (that is, passes them as first argument to pango_extents_to_pixels()).

Parameters:

  • ink_rect (Pango::Rectangle)

    rectangle used to store the extents of the layout as drawn or nil to indicate that the result is not needed.

  • logical_rect (Pango::Rectangle)

    rectangle used to store the logical extents of the layout or nil to indicate that the result is not needed.

Returns:

  • (nil)

#get_pixel_size(width, height) ⇒ nil

Determines the logical width and height of a Pango::Layout in device units. (pango_layout_get_size() returns the width and height scaled by %PANGO_SCALE.) This is simply a convenience function around pango_layout_get_pixel_extents().

Parameters:

  • width (Integer)

    location to store the logical width, or nil

  • height (Integer)

    location to store the logical height, or nil

Returns:

  • (nil)

#get_size(width, height) ⇒ nil

Determines the logical width and height of a Pango::Layout in Pango units (device units scaled by %PANGO_SCALE). This is simply a convenience function around pango_layout_get_extents().

Parameters:

  • width (Integer)

    location to store the logical width, or nil

  • height (Integer)

    location to store the logical height, or nil

Returns:

  • (nil)

#heightInteger

Gets the height of layout used for ellipsization. See pango_layout_set_height() for details. number of lines if negative.

Returns:

  • (Integer)

    the height, in Pango units if positive, or

#height=(height) ⇒ nil

Sets the height to which the Pango::Layout should be ellipsized at. There are two different behaviors, based on whether height is positive or negative.

If height is positive, it will be the maximum height of the layout. Only lines would be shown that would fit, and if there is any text omitted, an ellipsis added. At least one line is included in each paragraph regardless of how small the height value is. A value of zero will render exactly one line for the entire layout.

If height is negative, it will be the (negative of) maximum number of lines per paragraph. That is, the total number of lines shown may well be more than this value if the layout contains multiple paragraphs of text. The default value of -1 means that first line of each paragraph is ellipsized. This behvaior may be changed in the future to act per layout instead of per paragraph. File a bug against pango at <ulink url=“http://bugzilla.gnome.org/bugzilla.gnome.org/”>http://bugzilla.gnome.org/> if your code relies on this behavior.

Height setting only has effect if a positive width is set on layout and ellipsization mode of layout is not %PANGO_ELLIPSIZE_NONE. The behavior is undefined if a height other than -1 is set and ellipsization mode is set to %PANGO_ELLIPSIZE_NONE, and may change in the future.

Parameters:

  • height (Integer)

    the desired height of the layout in Pango units if positive, or desired number of lines if negative.

Returns:

  • (nil)

#indentInteger

Gets the paragraph indent width in Pango units. A negative value indicates a hanging indentation.

Returns:

  • (Integer)

    the indent in Pango units.

#indent=(indent) ⇒ nil

Sets the width in Pango units to indent each paragraph. A negative value of indent will produce a hanging indentation. That is, the first line will have the full width, and subsequent lines will be indented by the absolute value of indent.

The indent setting is ignored if layout alignment is set to %PANGO_ALIGN_CENTER.

Parameters:

  • indent (Integer)

    the amount by which to indent.

Returns:

  • (nil)

#index_to_line_x(index_, trailing, line, x_pos) ⇒ nil

Converts from byte index_ within the layout to line and X position. (X position is measured from the left edge of the line)

Parameters:

  • index_ (Integer)

    the byte index of a grapheme within the layout.

  • trailing (TrueClass)

    an integer indicating the edge of the grapheme to retrieve the position of. If > 0, the trailing edge of the grapheme, if 0, the leading of the grapheme.

  • line (Integer)

    location to store resulting line index. (which will between 0 and pango_layout_get_line_count(layout) - 1), or nil

  • x_pos (Integer)

    location to store resulting position within line (%PANGO_SCALE units per device unit), or nil

Returns:

  • (nil)

#index_to_pos(index_, pos) ⇒ nil

Converts from an index within a Pango::Layout to the onscreen position corresponding to the grapheme at that index, which is represented as rectangle. Note that <literal>pos->x</literal> is always the leading edge of the grapheme and <literal>pos->x + pos->width</literal> the trailing edge of the grapheme. If the directionality of the grapheme is right-to-left, then <literal>pos->width</literal> will be negative.

Parameters:

  • index_ (Integer)

    byte index within layout

  • pos (Pango::Rectangle)

    rectangle in which to store the position of the grapheme

Returns:

  • (nil)

#is_ellipsizedTrueClass

Queries whether the layout had to ellipsize any paragraphs.

This returns true if the ellipsization mode for layout is not %PANGO_ELLIPSIZE_NONE, a positive width is set on layout, and there are paragraphs exceeding that width that have to be ellipsized. otherwise.

Returns:

  • (TrueClass)

    true if any paragraphs had to be ellipsized, false

#is_wrappedTrueClass

Queries whether the layout had to wrap any paragraphs.

This returns true if a positive width is set on layout, ellipsization mode of layout is set to %PANGO_ELLIPSIZE_NONE, and there are paragraphs exceeding the layout width that have to be wrapped. otherwise.

Returns:

  • (TrueClass)

    true if any paragraphs had to be wrapped, false

#iterPango::LayoutIter

Returns an iterator to iterate over the visual extents of the layout.

Returns:

  • (Pango::LayoutIter)

    the new Pango::LayoutIter that should be freed using pango_layout_iter_free().

#justifyTrueClass

Gets whether each complete line should be stretched to fill the entire width of the layout.

Returns:

  • (TrueClass)

    the justify.

#justify=(justify) ⇒ nil

Sets whether each complete line should be stretched to fill the entire width of the layout. This stretching is typically done by adding whitespace, but for some scripts (such as Arabic), the justification may be done in more complex ways, like extending the characters.

Note that this setting is not implemented and so is ignored in Pango older than 1.18.

Parameters:

  • justify (TrueClass)

    whether the lines in the layout should be justified.

Returns:

  • (nil)

#line_countInteger

Retrieves the count of lines for the layout.

Returns:

  • (Integer)

    the line count.

#line_spacingPango::gfloat

Gets the value that has been set with pango_layout_set_line_spacing().

Returns:

  • (Pango::gfloat)

#line_spacing=(factor) ⇒ nil

Sets a factor for line spacing. Typical values are: 0, 1, 1.5, 2. The default values is 0.

If factor is non-zero, lines are placed so that

baseline2 = baseline1 + factor * height2

where height2 is the line height of the second line (as determined by the font(s)). In this case, the spacing set with pango_layout_set_spacing() is ignored.

If factor is zero, spacing is applied as before.

Parameters:

  • factor (Pango::gfloat)

    the new line spacing factor

Returns:

  • (nil)

#linesGLib::SList

Returns the lines of the layout as a list.

Use the faster pango_layout_get_lines_readonly() if you do not plan to modify the contents of the lines (glyphs, glyph widths, etc.). the lines in the layout. This points to internal data of the Pango::Layout and must be used with care. It will become invalid on any change to the layout’s text or properties.

Returns:

  • (GLib::SList)

    a #GSList containing

#lines_readonlyGLib::SList

Returns the lines of the layout as a list.

This is a faster alternative to pango_layout_get_lines(), but the user is not expected to modify the contents of the lines (glyphs, glyph widths, etc.). the lines in the layout. This points to internal data of the Pango::Layout and must be used with care. It will become invalid on any change to the layout’s text or properties. No changes should be made to the lines.

Returns:

  • (GLib::SList)

    a #GSList containing

#move_cursor_visually(strong, old_index, old_trailing, direction, new_index, new_trailing) ⇒ nil

Computes a new cursor position from an old position and a count of positions to move visually. If direction is positive, then the new strong cursor position will be one position to the right of the old cursor position. If direction is negative, then the new strong cursor position will be one position to the left of the old cursor position.

In the presence of bidirectional text, the correspondence between logical and visual order will depend on the direction of the current run, and there may be jumps when the cursor is moved off of the end of a run.

Motion here is in cursor positions, not in characters, so a single call to pango_layout_move_cursor_visually() may move the cursor over multiple characters when multiple characters combine to form a single grapheme.

Parameters:

  • strong (TrueClass)

    whether the moving cursor is the strong cursor or the weak cursor. The strong cursor is the cursor corresponding to text insertion in the base direction for the layout.

  • old_index (Integer)

    the byte index of the grapheme for the old index

  • old_trailing (Integer)

    if 0, the cursor was at the leading edge of the grapheme indicated by old_index, if > 0, the cursor was at the trailing edge.

  • direction (Integer)

    direction to move cursor. A negative value indicates motion to the left.

  • new_index (Integer)

    location to store the new cursor byte index. A value of -1 indicates that the cursor has been moved off the beginning of the layout. A value of %G_MAXINT indicates that the cursor has been moved off the end of the layout.

  • new_trailing (Integer)

    number of characters to move forward from the location returned for new_index to get the position where the cursor should be displayed. This allows distinguishing the position at the beginning of one line from the position at the end of the preceding line. new_index is always on the line where the cursor should be displayed.

Returns:

  • (nil)

#new(context) ⇒ Pango::Layout

Create a new Pango::Layout object with attributes initialized to default values for a particular Pango::Context.

Parameters:

Returns:

  • (Pango::Layout)

    the newly allocated Pango::Layout, with a reference count of one, which should be freed with g_object_unref().

#serialInteger

Returns the current serial number of layout. The serial number is initialized to an small number larger than zero when a new layout is created and is increased whenever the layout is changed using any of the setter functions, or the Pango::Context it uses has changed. The serial may wrap, but will never have the value 0. Since it can wrap, never compare it with “less than”, always use “not equals”.

This can be used to automatically detect changes to a Pango::Layout, and is useful for example to decide whether a layout needs redrawing. To force the serial to be increased, use pango_layout_context_changed().

Returns:

  • (Integer)

    The current serial number of layout.

#set_markup(markup, length) ⇒ nil

Same as pango_layout_set_markup_with_accel(), but the markup text isn’t scanned for accelerators.

Parameters:

  • markup (String)

    marked-up text

  • length (Integer)

    length of marked-up text in bytes, or -1 if markup is null-terminated

Returns:

  • (nil)

#set_markup_with_accel(markup, length, accel_marker, accel_char) ⇒ nil

Sets the layout text and attribute list from marked-up text (see <link linkend=“PangoMarkupFormat”>markup format</link>). Replaces the current text and attribute list.

If accel_marker is nonzero, the given character will mark the character following it as an accelerator. For example, accel_marker might be an ampersand or underscore. All characters marked as an accelerator will receive a %PANGO_UNDERLINE_LOW attribute, and the first character so marked will be returned in accel_char. Two accel_marker characters following each other produce a single literal accel_marker character. (see <link linkend=“PangoMarkupFormat”>markup format</link>)

Parameters:

  • markup (String)

    marked-up text

  • length (Integer)

    length of marked-up text in bytes, or -1 if markup is null-terminated

  • accel_marker (String)

    marker for accelerators in the text

  • accel_char (String)

    return location for first located accelerator, or nil

Returns:

  • (nil)

#set_text(text, length) ⇒ nil

Sets the text of the layout.

This function validates text and renders invalid UTF-8 with a placeholder glyph.

Note that if you have used pango_layout_set_markup() or pango_layout_set_markup_with_accel() on layout before, you may want to call pango_layout_set_attributes() to clear the attributes set on the layout from the markup as this function does not clear attributes.

Parameters:

  • text (String)

    the text

  • length (Integer)

    maximum length of text, in bytes. -1 indicates that the string is nul-terminated and the length should be calculated. The text will also be truncated on encountering a nul-termination even when length is positive.

Returns:

  • (nil)

#single_paragraph_modeTrueClass

Obtains the value set by pango_layout_set_single_paragraph_mode(). paragraph separator characters, false otherwise.

Returns:

  • (TrueClass)

    true if the layout does not break paragraphs at

#single_paragraph_mode=(setting) ⇒ nil

If setting is true, do not treat newlines and similar characters as paragraph separators; instead, keep all text in a single paragraph, and display a glyph for paragraph separator characters. Used when you want to allow editing of newlines on a single text line.

Parameters:

  • setting (TrueClass)

    new setting

Returns:

  • (nil)

#spacingInteger

Gets the amount of spacing between the lines of the layout.

Returns:

  • (Integer)

    the spacing in Pango units.

#spacing=(spacing) ⇒ nil

Sets the amount of spacing in Pango unit between the lines of the layout. When placing lines with spacing, Pango arranges things so that

line2.top = line1.bottom + spacing

Note: Since 1.44, Pango defaults to using the line height (as determined by the font) for placing lines. The spacing set with this function is only taken into account when the line-height factor is set to zero with pango_layout_set_line_spacing().

Parameters:

  • spacing (Integer)

    the amount of spacing

Returns:

  • (nil)

#tabsPango::TabArray

Gets the current Pango::TabArray used by this layout. If no Pango::TabArray has been set, then the default tabs are in use and nil is returned. Default tabs are every 8 spaces. The return value should be freed with pango_tab_array_free(). nil.

Returns:

  • (Pango::TabArray)

    a copy of the tabs for this layout, or

#tabs=(tabs) ⇒ nil

Sets the tabs to use for layout, overriding the default tabs (by default, tabs are every 8 spaces). If tabs is nil, the default tabs are reinstated. tabs is copied into the layout; you must free your copy of tabs yourself.

Parameters:

  • tabs (Pango::TabArray)

    a Pango::TabArray, or nil

Returns:

  • (nil)

#textString

Gets the text in the layout. The returned text should not be freed or modified.

Returns:

  • (String)

    the text in the layout.

#unknown_glyphs_countInteger

Counts the number unknown glyphs in layout. That is, zero if glyphs for all characters in the layout text were found, or more than zero otherwise.

This function can be used to determine if there are any fonts available to render all characters in a certain string, or when used in combination with %PANGO_ATTR_FALLBACK, to check if a certain font supports all the characters in the string.

Returns:

  • (Integer)

    The number of unknown glyphs in layout.

#widthInteger

Gets the width to which the lines of the Pango::Layout should wrap.

Returns:

  • (Integer)

    the width in Pango units, or -1 if no width set.

#width=(width) ⇒ nil

Sets the width to which the lines of the Pango::Layout should wrap or ellipsized. The default value is -1: no width set.

Parameters:

  • width (Integer)

    the desired width in Pango units, or -1 to indicate that no wrapping or ellipsization should be performed.

Returns:

  • (nil)

#wrapPango::WrapMode

Gets the wrap mode for the layout.

Use pango_layout_is_wrapped() to query whether any paragraphs were actually wrapped.

Returns:

#wrap=(wrap) ⇒ nil

Sets the wrap mode; the wrap mode only has effect if a width is set on the layout with pango_layout_set_width(). To turn off wrapping, set the width to -1.

Parameters:

Returns:

  • (nil)

#xy_to_index(x, y, index_, trailing) ⇒ TrueClass

Converts from X and Y position within a layout to the byte index to the character at that logical position. If the Y position is not inside the layout, the closest position is chosen (the position will be clamped inside the layout). If the X position is not within the layout, then the start or the end of the line is chosen as described for pango_layout_line_x_to_index(). If either the X or Y positions were not inside the layout, then the function returns false; on an exact hit, it returns true.

Parameters:

  • x (Integer)

    the X offset (in Pango units) from the left edge of the layout.

  • y (Integer)

    the Y offset (in Pango units) from the top edge of the layout

  • index_ (Integer)

    location to store calculated byte index

  • trailing (Integer)

    location to store a integer indicating where in the grapheme the user clicked. It will either be zero, or the number of characters in the grapheme. 0 represents the leading edge of the grapheme.

Returns:

  • (TrueClass)

    true if the coordinates were inside text, false otherwise.