def render_cluster_glyph_items(
ctx: cairocffi.Context,
layout: pangocffi.Layout
):
"""
Renders each cluster within a layout with a unique rotation and color.
Warning: Does not support bidirectional text.
:param ctx:
a Cairo context
:param layout:
a Pango layout
"""
layout_run_iter = layout.get_iter()
layout_cluster_iter = layout.get_iter()
layout_text = layout.get_text()
alternate = False
while True:
layout_run = layout_run_iter.get_run()
layout_line_baseline = layout_run_iter.get_baseline()
if layout_run is None:
if not layout_run_iter.next_run():
break
continue
clusters = get_clusters_from_glyph_item(layout_run, layout_text)
for cluster in clusters:
cluster_extents = layout_cluster_iter.get_cluster_extents()[1]
layout_cluster_iter.next_cluster()
alternate = not alternate
ctx.set_source_rgba(0.5, 0, 1 if alternate else 0.5, 0.9)
ctx.save()
ctx.translate(
pangocffi.units_to_double(cluster_extents.x),
pangocffi.units_to_double(layout_line_baseline)
)
ctx.rotate(-0.05 if alternate else 0.05)
pangocairocffi.show_glyph_item(
ctx,
layout_text,
cluster
)
ctx.restore()
if not layout_run_iter.next_run():
break
def test_layout_iter_properties():
context = Context()
layout = Layout(context)
layout_iter = layout.get_iter()
assert layout_iter.next_run() is False
assert layout_iter.next_char() is False
assert layout_iter.next_cluster() is False
assert layout_iter.next_line() is False
assert layout_iter.at_last_line() is True
assert layout_iter.get_index() == 0
assert layout_iter.get_baseline() == 0
assert isinstance(layout_iter.get_char_extents(), Rectangle)
cluster_ink, cluster_logical = layout_iter.get_cluster_extents()
assert isinstance(cluster_ink, Rectangle)
assert isinstance(cluster_logical, Rectangle)
run_ink, run_logical = layout_iter.get_run_extents()
assert isinstance(run_ink, Rectangle)
assert isinstance(run_logical, Rectangle)
y0, y1 = layout_iter.get_line_yrange()
assert y0 == 0
assert y1 == 0
line_ink, line_logical = layout_iter.get_line_extents()
assert isinstance(line_ink, Rectangle)
assert isinstance(line_logical, Rectangle)
layout_ink, layout_logical = layout_iter.get_layout_extents()
assert isinstance(layout_ink, Rectangle)
assert isinstance(layout_logical, Rectangle)
def test_glyph_item_iterator(self):
text = 'Hi from Παν語'
layout = Layout(self.pango_context)
layout.set_text(text)
layout_iter = layout.get_iter()
glyph_item_iter = GlyphItemIter()
assert isinstance(glyph_item_iter.get_pointer(), ffi.CData)
assert glyph_item_iter.init_start(
layout_iter.get_run(),
text
)
assert isinstance(glyph_item_iter.glyph_item, GlyphItem)
assert glyph_item_iter.text == text
# Verify first cluster
assert glyph_item_iter.start_glyph == 0
assert glyph_item_iter.start_index == 0
assert glyph_item_iter.start_char == 0
assert glyph_item_iter.end_glyph == 1
assert glyph_item_iter.end_index == 1
assert glyph_item_iter.end_char == 1
assert not glyph_item_iter.prev_cluster()
assert glyph_item_iter.next_cluster()
# Verify second cluster
assert glyph_item_iter.start_glyph == 1
assert glyph_item_iter.start_index == 1
assert glyph_item_iter.start_char == 1
assert glyph_item_iter.end_glyph == 2
assert glyph_item_iter.end_index == 2
assert glyph_item_iter.end_char == 2
assert glyph_item_iter.init_end(
layout_iter.get_run(),
text
)
# Verify last cluster
assert glyph_item_iter.start_glyph == 7
assert glyph_item_iter.start_index == 7
assert glyph_item_iter.start_char == 7
assert glyph_item_iter.end_glyph == 8
assert glyph_item_iter.end_index == 8
assert glyph_item_iter.end_char == 8
assert not glyph_item_iter.next_cluster()
assert glyph_item_iter.prev_cluster()
# Verify second to last cluster
assert glyph_item_iter.start_glyph == 6
assert glyph_item_iter.start_index == 6
assert glyph_item_iter.start_char == 6
assert glyph_item_iter.end_glyph == 7
assert glyph_item_iter.end_index == 7
assert glyph_item_iter.end_char == 7
def test_layout_run_properties(self):
layout = Layout(self.pango_context)
layout.set_text('Hello World')
layout_iter = layout.get_iter()
layout_run = layout_iter.get_run()
layout_run_item = layout_run.item
assert isinstance(layout_run_item, Item)
def test_glyph_item_copies(self):
text = 'Hi from Παν語'
layout = Layout(self.pango_context)
layout.set_text(text)
layout_iter = layout.get_iter()
layout_run = layout_iter.get_run()
assert layout_run.copy().get_pointer() != layout_run.get_pointer()
def test_layout_run_from_pointer(self):
layout = Layout(self.pango_context)
layout.set_text('Hello World')
layout_iter = layout.get_iter()
layout_run = layout_iter.get_run()
same_layout = LayoutRun.from_pointer(layout_run.get_pointer())
assert isinstance(same_layout, LayoutRun)
def test_glyph_item_get_logical_widths(self):
text = 'Hi from Παν語'
layout = Layout(self.pango_context)
layout.set_text(text)
layout_iter = layout.get_iter()
layout_run = layout_iter.get_run()
logical_widths = layout_run.get_logical_widths(text)
assert len(logical_widths) == 8
assert isinstance(logical_widths[0], int)
def test_layout_iter_pointer(self):
layout = Layout(self.pango_context)
layout_iter = layout.get_iter()
assert isinstance(layout_iter, LayoutIter)
assert isinstance(layout_iter.get_pointer(), ffi.CData)
pointer_shallow_copy = layout_iter.get_pointer()
layout_iter_shallow_copy = LayoutIter.from_pointer(
pointer_shallow_copy
)
assert isinstance(layout_iter_shallow_copy, LayoutIter)
assert isinstance(layout_iter_shallow_copy.get_pointer(), ffi.CData)
def test_glyph_item_splits(self):
text = 'Hi from Παν語'
layout = Layout(self.pango_context)
layout.set_text(text)
layout_iter = layout.get_iter()
layout_run = layout_iter.get_run()
layout_run_hi = layout_run.split(text, 3)
# Substring "Hi "
assert layout_run_hi.item.num_chars == 3
assert layout_run_hi.item.offset == 0
# Substring "from "
assert layout_run.item.num_chars == 5
assert layout_run.item.offset == 3
def _show_layout_baseline(
context: cairocffi.Context,
layout: pangocffi.Layout
):
layout_iter = layout.get_iter()
context.set_line_width(0.5)
context.set_dash([1, 1])
while True:
extents = layout_iter.get_line_extents()
baseline = layout_iter.get_baseline()
y_ranges = layout_iter.get_line_yrange()
context.set_source_rgba(1, 0, 0, 0.9)
context.move_to(
pangocffi.units_to_double(extents[0].x),
pangocffi.units_to_double(y_ranges[0])
)
context.line_to(
pangocffi.units_to_double(extents[0].x + extents[0].width),
pangocffi.units_to_double(y_ranges[0])
)
context.stroke()
context.set_source_rgba(0, 1, 0, 0.9)
context.stroke()
context.move_to(
pangocffi.units_to_double(extents[0].x),
pangocffi.units_to_double(baseline)
)
context.line_to(
pangocffi.units_to_double(extents[0].x + extents[0].width),
pangocffi.units_to_double(baseline)
)
context.stroke()
context.set_source_rgba(0, 0, 1, 0.9)
context.move_to(
pangocffi.units_to_double(extents[0].x),
pangocffi.units_to_double(y_ranges[1])
)
context.line_to(
pangocffi.units_to_double(extents[0].x + extents[0].width),
pangocffi.units_to_double(y_ranges[1])
)
context.stroke()
if not layout_iter.next_run():
break
def _show_layout_line_logical_extents(
context: cairocffi.Context,
layout: pangocffi.Layout
):
layout_iter = layout.get_iter()
context.set_line_width(0.5)
context.set_dash([1, 1])
alternate = True
while True:
alternate = not alternate
extents = layout_iter.get_line_extents()
context.set_source_rgba(0, 0, 1 if alternate else 0.5, 0.9)
_rectangle_path(context, extents[1])
context.stroke()
_coordinate_path(context, (extents[1].x, extents[1].y))
context.fill()
if not layout_iter.next_run():
break
def test_item_properties(self):
layout = Layout(self.pango_context)
layout.set_text('Hi from Παν語')
layout_iter = layout.get_iter()
layout_run = layout_iter.get_run()
layout_run_item = layout_run.item
assert layout_run_item.length == 8
assert layout_run_item.offset == 0
assert layout_run_item.num_chars == 8
assert isinstance(layout_run_item.get_pointer(), ffi.CData)
assert layout_iter.next_run()
layout_run = layout_iter.get_run()
layout_run_item = layout_run.item
assert layout_run_item.length == 6
assert layout_run_item.offset == 8
assert layout_run_item.num_chars == 3
assert isinstance(layout_run_item.get_pointer(), ffi.CData)
def render_run_glyph_items(
ctx: cairocffi.Context,
layout: pangocffi.Layout
) -> None:
"""
Renders each layout run within a layout with a unique rotation and color.
:param ctx:
a Cairo context
:param layout:
a Pango layout
"""
layout_iter = layout.get_iter()
layout_text = layout.get_text()
alternate = False
while True:
layout_run = layout_iter.get_run()
layout_run_extents = layout_iter.get_run_extents()[1]
layout_line_baseline = layout_iter.get_baseline()
if layout_run is None:
if not layout_iter.next_run():
break
continue
alternate = not alternate
ctx.set_source_rgba(0, 0.5, 1 if alternate else 0.5, 0.9)
ctx.save()
ctx.translate(
pangocffi.units_to_double(layout_run_extents.x),
pangocffi.units_to_double(layout_line_baseline)
)
ctx.rotate(0.05 if alternate else -0.05)
pangocairocffi.show_glyph_item(ctx, layout_text, layout_run)
ctx.restore()
if not layout_iter.next_run():
break
def test_layout_iter_properties(self):
layout = Layout(self.pango_context)
layout_iter = layout.get_iter()
assert layout_iter.next_run() is False
assert layout_iter.next_char() is False
assert layout_iter.next_cluster() is False
assert layout_iter.next_line() is False
assert layout_iter.at_last_line() is True
assert layout_iter.get_index() == 0
# Even with no text in the layout, the layout will still have a
# baseline corresponding to the selected font description.
assert layout_iter.get_baseline() > 0
assert isinstance(layout_iter.get_char_extents(), Rectangle)
cluster_ink, cluster_logical = layout_iter.get_cluster_extents()
assert isinstance(cluster_ink, Rectangle)
assert isinstance(cluster_logical, Rectangle)
run_ink, run_logical = layout_iter.get_run_extents()
assert isinstance(run_ink, Rectangle)
assert isinstance(run_logical, Rectangle)
y0, y1 = layout_iter.get_line_yrange()
assert y0 == 0
# Even with no text in the layout, the layout will still have a
# y-range corresponding to the selected font description.
assert y1 > 0
line_ink, line_logical = layout_iter.get_line_extents()
assert isinstance(line_ink, Rectangle)
assert isinstance(line_logical, Rectangle)
layout_ink, layout_logical = layout_iter.get_layout_extents()
assert isinstance(layout_ink, Rectangle)
assert isinstance(layout_logical, Rectangle)
def _show_layout_y_ranges(
context: cairocffi.Context,
layout: pangocffi.Layout
):
layout_iter = layout.get_iter()
context.set_line_width(0.5)
context.set_dash([1, 1])
alternate = True
while True:
alternate = not alternate
extents = layout_iter.get_line_extents()
y_ranges = layout_iter.get_line_yrange()
context.set_source_rgba(0, 0, 1 if alternate else 0.5, 0.9)
context.move_to(
pangocffi.units_to_double(extents[0].x),
pangocffi.units_to_double(y_ranges[0])
)
context.line_to(
pangocffi.units_to_double(extents[0].x + extents[0].width),
pangocffi.units_to_double(y_ranges[0])
)
context.stroke()
context.move_to(
pangocffi.units_to_double(extents[0].x),
pangocffi.units_to_double(y_ranges[1])
)
context.line_to(
pangocffi.units_to_double(extents[0].x + extents[0].width),
pangocffi.units_to_double(y_ranges[1])
)
context.stroke()
if not layout_iter.next_run():
break
def compute_subtext_extents(layout: Layout, parsed_text,
id_index: int) -> Tuple[float, float]:
"""
Returns the x coordinate and width of a subtext of a single line.
"""
assert layout.get_line_count() == 1
(start, end) = get_byte_range(parsed_text, id_index)
iter = layout.get_iter()
x = None
width = 0
while True:
byte_offset = iter.get_index()
if start <= byte_offset < end:
extents = from_pango_rect(iter.get_char_extents())
if x is None:
assert start == byte_offset
x = extents.x
width += extents.width
if byte_offset >= end or not iter.next_char():
break
assert x is not None
return (x, width)
def test_layout_iter_pointer():
context = Context()
layout = Layout(context)
layout_iter = layout.get_iter()
assert isinstance(layout_iter.get_pointer(), ffi.CData)
def test_layout_iterator_run_returns_none(self):
layout = Layout(self.pango_context)
layout_iter = layout.get_iter()
assert layout_iter.get_run() is None
def test_layout_iterator_run_returns_none():
context = Context()
layout = Layout(context)
layout_iter = layout.get_iter()
assert layout_iter.get_run() is None