1131 lines
43 KiB
Python
1131 lines
43 KiB
Python
"""
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weasyprint.draw
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---------------
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Take an "after layout" box tree and draw it onto a cairo context.
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:copyright: Copyright 2011-2019 Simon Sapin and contributors, see AUTHORS.
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:license: BSD, see LICENSE for details.
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"""
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import contextlib
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import operator
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from math import ceil, floor, hypot, pi, sqrt, tan
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import cairocffi as cairo
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from .formatting_structure import boxes
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from .images import SVGImage
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from .layout import replaced
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from .layout.backgrounds import BackgroundLayer
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from .stacking import StackingContext
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from .text import show_first_line
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SIDES = ('top', 'right', 'bottom', 'left')
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CROP = '''
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<!-- horizontal top left -->
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<path d="M0,{bleed_top} h{half_bleed_left}" />
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<!-- horizontal top right -->
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<path d="M0,{bleed_top} h{half_bleed_right}"
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transform="translate({width},0) scale(-1,1)" />
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<!-- horizontal bottom right -->
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<path d="M0,{bleed_bottom} h{half_bleed_right}"
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transform="translate({width},{height}) scale(-1,-1)" />
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<!-- horizontal bottom left -->
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<path d="M0,{bleed_bottom} h{half_bleed_left}"
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transform="translate(0,{height}) scale(1,-1)" />
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<!-- vertical top left -->
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<path d="M{bleed_left},0 v{half_bleed_top}" />
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<!-- vertical bottom right -->
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<path d="M{bleed_right},0 v{half_bleed_bottom}"
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transform="translate({width},{height}) scale(-1,-1)" />
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<!-- vertical bottom left -->
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<path d="M{bleed_left},0 v{half_bleed_bottom}"
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transform="translate(0,{height}) scale(1,-1)" />
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<!-- vertical top right -->
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<path d="M{bleed_right},0 v{half_bleed_top}"
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transform="translate({width},0) scale(-1,1)" />
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'''
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CROSS = '''
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<!-- top -->
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<circle r="{half_bleed_top}"
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transform="scale(0.5)
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translate({width},{half_bleed_top}) scale(0.5)" />
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<path d="M-{half_bleed_top},{half_bleed_top} h{bleed_top}
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M0,0 v{bleed_top}"
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transform="scale(0.5) translate({width},0)" />
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<!-- bottom -->
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<circle r="{half_bleed_bottom}"
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transform="translate(0,{height}) scale(0.5)
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translate({width},-{half_bleed_bottom}) scale(0.5)" />
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<path d="M-{half_bleed_bottom},-{half_bleed_bottom} h{bleed_bottom}
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M0,0 v-{bleed_bottom}"
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transform="translate(0,{height}) scale(0.5) translate({width},0)" />
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<!-- left -->
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<circle r="{half_bleed_left}"
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transform="scale(0.5)
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translate({half_bleed_left},{height}) scale(0.5)" />
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<path d="M{half_bleed_left},-{half_bleed_left} v{bleed_left}
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M0,0 h{bleed_left}"
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transform="scale(0.5) translate(0,{height})" />
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<!-- right -->
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<circle r="{half_bleed_right}"
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transform="translate({width},0) scale(0.5)
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translate(-{half_bleed_right},{height}) scale(0.5)" />
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<path d="M-{half_bleed_right},-{half_bleed_right} v{bleed_right}
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M0,0 h-{bleed_right}"
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transform="translate({width},0)
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scale(0.5) translate(0,{height})" />
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'''
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@contextlib.contextmanager
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def stacked(context):
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"""Save and restore the context when used with the ``with`` keyword."""
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context.save()
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try:
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yield
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finally:
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context.restore()
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def hsv2rgb(hue, saturation, value):
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"""Transform a HSV color to a RGB color."""
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c = value * saturation
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x = c * (1 - abs((hue / 60) % 2 - 1))
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m = value - c
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if 0 <= hue < 60:
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return c + m, x + m, m
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elif 60 <= hue < 120:
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return x + m, c + m, m
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elif 120 <= hue < 180:
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return m, c + m, x + m
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elif 180 <= hue < 240:
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return m, x + m, c + m
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elif 240 <= hue < 300:
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return x + m, m, c + m
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elif 300 <= hue < 360:
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return c + m, m, x + m
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def rgb2hsv(red, green, blue):
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"""Transform a RGB color to a HSV color."""
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cmax = max(red, green, blue)
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cmin = min(red, green, blue)
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delta = cmax - cmin
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if delta == 0:
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hue = 0
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elif cmax == red:
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hue = 60 * ((green - blue) / delta % 6)
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elif cmax == green:
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hue = 60 * ((blue - red) / delta + 2)
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elif cmax == blue:
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hue = 60 * ((red - green) / delta + 4)
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saturation = 0 if delta == 0 else delta / cmax
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return hue, saturation, cmax
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def get_color(style, key):
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value = style[key]
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return value if value != 'currentColor' else style['color']
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def darken(color):
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"""Return a darker color."""
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hue, saturation, value = rgb2hsv(color.red, color.green, color.blue)
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value /= 1.5
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saturation /= 1.25
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return hsv2rgb(hue, saturation, value) + (color.alpha,)
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def lighten(color):
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"""Return a lighter color."""
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hue, saturation, value = rgb2hsv(color.red, color.green, color.blue)
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value = 1 - (1 - value) / 1.5
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if saturation:
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saturation = 1 - (1 - saturation) / 1.25
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return hsv2rgb(hue, saturation, value) + (color.alpha,)
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def draw_page(page, context, enable_hinting):
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"""Draw the given PageBox."""
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bleed = {
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side: page.style['bleed_%s' % side].value
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for side in ('top', 'right', 'bottom', 'left')}
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marks = page.style['marks']
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stacking_context = StackingContext.from_page(page)
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draw_background(
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context, stacking_context.box.background, enable_hinting,
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clip_box=False, bleed=bleed, marks=marks)
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draw_background(
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context, page.canvas_background, enable_hinting, clip_box=False)
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draw_border(context, page, enable_hinting)
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draw_stacking_context(context, stacking_context, enable_hinting)
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def draw_box_background_and_border(context, page, box, enable_hinting):
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draw_background(context, box.background, enable_hinting)
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if isinstance(box, boxes.TableBox):
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draw_table_backgrounds(context, page, box, enable_hinting)
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if box.style['border_collapse'] == 'separate':
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draw_border(context, box, enable_hinting)
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for row_group in box.children:
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for row in row_group.children:
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for cell in row.children:
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if (cell.style['empty_cells'] == 'show' or
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not cell.empty):
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draw_border(context, cell, enable_hinting)
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else:
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draw_collapsed_borders(context, box, enable_hinting)
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else:
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draw_border(context, box, enable_hinting)
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def draw_stacking_context(context, stacking_context, enable_hinting):
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"""Draw a ``stacking_context`` on ``context``."""
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# See http://www.w3.org/TR/CSS2/zindex.html
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with stacked(context):
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box = stacking_context.box
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if box.is_absolutely_positioned() and box.style['clip']:
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top, right, bottom, left = box.style['clip']
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if top == 'auto':
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top = 0
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if right == 'auto':
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right = 0
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if bottom == 'auto':
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bottom = box.border_height()
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if left == 'auto':
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left = box.border_width()
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context.rectangle(
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box.border_box_x() + right,
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box.border_box_y() + top,
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left - right,
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bottom - top)
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context.clip()
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if box.style['opacity'] < 1:
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context.push_group()
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if box.transformation_matrix:
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try:
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box.transformation_matrix.copy().invert()
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except cairo.CairoError:
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return
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else:
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context.transform(box.transformation_matrix)
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# Point 1 is done in draw_page
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# Point 2
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if isinstance(box, (boxes.BlockBox, boxes.MarginBox,
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boxes.InlineBlockBox, boxes.TableCellBox,
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boxes.FlexContainerBox)):
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# The canvas background was removed by set_canvas_background
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draw_box_background_and_border(
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context, stacking_context.page, box, enable_hinting)
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with stacked(context):
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if box.style['overflow'] != 'visible':
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# Only clip the content and the children:
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# - the background is already clipped
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# - the border must *not* be clipped
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rounded_box_path(context, box.rounded_padding_box())
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context.clip()
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# Point 3
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for child_context in stacking_context.negative_z_contexts:
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draw_stacking_context(context, child_context, enable_hinting)
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# Point 4
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for block in stacking_context.block_level_boxes:
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draw_box_background_and_border(
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context, stacking_context.page, block, enable_hinting)
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# Point 5
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for child_context in stacking_context.float_contexts:
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draw_stacking_context(context, child_context, enable_hinting)
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# Point 6
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if isinstance(box, boxes.InlineBox):
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draw_inline_level(
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context, stacking_context.page, box, enable_hinting)
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# Point 7
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for block in [box] + stacking_context.blocks_and_cells:
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if isinstance(block, boxes.ReplacedBox):
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draw_replacedbox(context, block)
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else:
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for child in block.children:
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if isinstance(child, boxes.LineBox):
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draw_inline_level(
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context, stacking_context.page, child,
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enable_hinting)
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# Point 8
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for child_context in stacking_context.zero_z_contexts:
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draw_stacking_context(context, child_context, enable_hinting)
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# Point 9
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for child_context in stacking_context.positive_z_contexts:
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draw_stacking_context(context, child_context, enable_hinting)
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# Point 10
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draw_outlines(context, box, enable_hinting)
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if box.style['opacity'] < 1:
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context.pop_group_to_source()
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context.paint_with_alpha(box.style['opacity'])
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def rounded_box_path(context, radii):
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"""Draw the path of the border radius box.
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``widths`` is a tuple of the inner widths (top, right, bottom, left) from
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the border box. Radii are adjusted from these values. Default is (0, 0, 0,
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0).
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Inspired by cairo cookbook
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http://cairographics.org/cookbook/roundedrectangles/
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"""
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x, y, w, h, tl, tr, br, bl = radii
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if 0 in tl:
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tl = (0, 0)
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if 0 in tr:
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tr = (0, 0)
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if 0 in br:
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br = (0, 0)
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if 0 in bl:
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bl = (0, 0)
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if (tl, tr, br, bl) == 4 * ((0, 0),):
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# No radius, draw a rectangle
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context.rectangle(x, y, w, h)
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return
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context.move_to(x, y)
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context.new_sub_path()
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for i, (w, h, (rx, ry)) in enumerate((
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(0, 0, tl), (w, 0, tr), (w, h, br), (0, h, bl))):
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context.save()
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context.translate(x + w, y + h)
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radius = max(rx, ry)
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if radius:
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context.scale(min(rx / ry, 1), min(ry / rx, 1))
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context.arc(
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(-1 if w else 1) * radius, (-1 if h else 1) * radius, radius,
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(2 + i) * pi / 2, (3 + i) * pi / 2)
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context.restore()
|
||
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||
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def draw_background(context, bg, enable_hinting, clip_box=True, bleed=None,
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marks=()):
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"""Draw the background color and image to a ``cairo.Context``.
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||
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If ``clip_box`` is set to ``False``, the background is not clipped to the
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border box of the background, but only to the painting area.
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||
|
||
"""
|
||
if bg is None:
|
||
return
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||
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||
with stacked(context):
|
||
if enable_hinting:
|
||
# Prefer crisp edges on background rectangles.
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||
context.set_antialias(cairo.ANTIALIAS_NONE)
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||
|
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if clip_box:
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for box in bg.layers[-1].clipped_boxes:
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rounded_box_path(context, box)
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context.clip()
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||
|
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# Background color
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||
if bg.color.alpha > 0:
|
||
with stacked(context):
|
||
painting_area = bg.layers[-1].painting_area
|
||
if painting_area:
|
||
if bleed:
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||
# Painting area is the PDF BleedBox
|
||
x, y, width, height = painting_area
|
||
painting_area = (
|
||
x - bleed['left'], y - bleed['top'],
|
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width + bleed['left'] + bleed['right'],
|
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height + bleed['top'] + bleed['bottom'])
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context.rectangle(*painting_area)
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context.clip()
|
||
context.set_source_rgba(*bg.color)
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||
context.paint()
|
||
|
||
if bleed and marks:
|
||
x, y, width, height = bg.layers[-1].painting_area
|
||
x -= bleed['left']
|
||
y -= bleed['top']
|
||
width += bleed['left'] + bleed['right']
|
||
height += bleed['top'] + bleed['bottom']
|
||
svg = '''
|
||
<svg height="{height}" width="{width}"
|
||
fill="transparent" stroke="black" stroke-width="1"
|
||
xmlns="http://www.w3.org/2000/svg"
|
||
xmlns:xlink="http://www.w3.org/1999/xlink">
|
||
'''
|
||
if 'crop' in marks:
|
||
svg += CROP
|
||
if 'cross' in marks:
|
||
svg += CROSS
|
||
svg += '</svg>'
|
||
half_bleed = {key: value * 0.5 for key, value in bleed.items()}
|
||
image = SVGImage(svg.format(
|
||
height=height, width=width,
|
||
bleed_left=bleed['left'], bleed_right=bleed['right'],
|
||
bleed_top=bleed['top'], bleed_bottom=bleed['bottom'],
|
||
half_bleed_left=half_bleed['left'],
|
||
half_bleed_right=half_bleed['right'],
|
||
half_bleed_top=half_bleed['top'],
|
||
half_bleed_bottom=half_bleed['bottom'],
|
||
), '', None)
|
||
# Painting area is the PDF media box
|
||
size = (width, height)
|
||
position = (x, y)
|
||
repeat = ('no-repeat', 'no-repeat')
|
||
unbounded = True
|
||
painting_area = position + size
|
||
positioning_area = (0, 0, width, height)
|
||
clipped_boxes = []
|
||
layer = BackgroundLayer(
|
||
image, size, position, repeat, unbounded, painting_area,
|
||
positioning_area, clipped_boxes)
|
||
bg.layers.insert(0, layer)
|
||
# Paint in reversed order: first layer is "closest" to the viewer.
|
||
for layer in reversed(bg.layers):
|
||
draw_background_image(context, layer, bg.image_rendering)
|
||
|
||
|
||
def draw_table_backgrounds(context, page, table, enable_hinting):
|
||
"""Draw the background color and image of the table children."""
|
||
for column_group in table.column_groups:
|
||
draw_background(context, column_group.background, enable_hinting)
|
||
for column in column_group.children:
|
||
draw_background(context, column.background, enable_hinting)
|
||
for row_group in table.children:
|
||
draw_background(context, row_group.background, enable_hinting)
|
||
for row in row_group.children:
|
||
draw_background(context, row.background, enable_hinting)
|
||
for cell in row.children:
|
||
if (table.style['border_collapse'] == 'collapse' or
|
||
cell.style['empty_cells'] == 'show' or
|
||
not cell.empty):
|
||
draw_background(context, cell.background, enable_hinting)
|
||
|
||
|
||
def draw_background_image(context, layer, image_rendering):
|
||
if layer.image is None:
|
||
return
|
||
|
||
painting_x, painting_y, painting_width, painting_height = (
|
||
layer.painting_area)
|
||
positioning_x, positioning_y, positioning_width, positioning_height = (
|
||
layer.positioning_area)
|
||
position_x, position_y = layer.position
|
||
repeat_x, repeat_y = layer.repeat
|
||
image_width, image_height = layer.size
|
||
|
||
if repeat_x == 'no-repeat':
|
||
# We want at least the whole image_width drawn on sub_surface, but we
|
||
# want to be sure it will not be repeated on the painting_width.
|
||
repeat_width = max(image_width, painting_width)
|
||
elif repeat_x in ('repeat', 'round'):
|
||
# We repeat the image each image_width.
|
||
repeat_width = image_width
|
||
else:
|
||
assert repeat_x == 'space'
|
||
n_repeats = floor(positioning_width / image_width)
|
||
if n_repeats >= 2:
|
||
# The repeat width is the whole positioning width with one image
|
||
# removed, divided by (the number of repeated images - 1). This
|
||
# way, we get the width of one image + one space. We ignore
|
||
# background-position for this dimension.
|
||
repeat_width = (positioning_width - image_width) / (n_repeats - 1)
|
||
position_x = 0
|
||
else:
|
||
# We don't repeat the image.
|
||
repeat_width = image_width
|
||
|
||
# Comments above apply here too.
|
||
if repeat_y == 'no-repeat':
|
||
repeat_height = max(image_height, painting_height)
|
||
elif repeat_y in ('repeat', 'round'):
|
||
repeat_height = image_height
|
||
else:
|
||
assert repeat_y == 'space'
|
||
n_repeats = floor(positioning_height / image_height)
|
||
if n_repeats >= 2:
|
||
repeat_height = (
|
||
positioning_height - image_height) / (n_repeats - 1)
|
||
position_y = 0
|
||
else:
|
||
repeat_height = image_height
|
||
|
||
sub_surface = cairo.PDFSurface(None, repeat_width, repeat_height)
|
||
sub_context = cairo.Context(sub_surface)
|
||
sub_context.rectangle(0, 0, image_width, image_height)
|
||
sub_context.clip()
|
||
layer.image.draw(sub_context, image_width, image_height, image_rendering)
|
||
pattern = cairo.SurfacePattern(sub_surface)
|
||
|
||
if repeat_x == repeat_y == 'no-repeat':
|
||
pattern.set_extend(cairo.EXTEND_NONE)
|
||
else:
|
||
pattern.set_extend(cairo.EXTEND_REPEAT)
|
||
|
||
with stacked(context):
|
||
if not layer.unbounded:
|
||
context.rectangle(painting_x, painting_y,
|
||
painting_width, painting_height)
|
||
context.clip()
|
||
# else: unrestricted, whole page box
|
||
|
||
context.translate(positioning_x + position_x,
|
||
positioning_y + position_y)
|
||
context.set_source(pattern)
|
||
context.paint()
|
||
|
||
|
||
def xy_offset(x, y, offset_x, offset_y, offset):
|
||
"""Increment X and Y coordinates by the given offsets."""
|
||
return x + offset_x * offset, y + offset_y * offset
|
||
|
||
|
||
def styled_color(style, color, side):
|
||
if style in ('inset', 'outset'):
|
||
do_lighten = (side in ('top', 'left')) ^ (style == 'inset')
|
||
return (lighten if do_lighten else darken)(color)
|
||
elif style in ('ridge', 'groove'):
|
||
if (side in ('top', 'left')) ^ (style == 'ridge'):
|
||
return lighten(color), darken(color)
|
||
else:
|
||
return darken(color), lighten(color)
|
||
return color
|
||
|
||
|
||
def draw_border(context, box, enable_hinting):
|
||
"""Draw the box border to a ``cairo.Context``."""
|
||
# We need a plan to draw beautiful borders, and that's difficult, no need
|
||
# to lie. Let's try to find the cases that we can handle in a smart way.
|
||
|
||
def draw_column_border():
|
||
"""Draw column borders."""
|
||
columns = (
|
||
isinstance(box, boxes.BlockContainerBox) and (
|
||
box.style['column_width'] != 'auto' or
|
||
box.style['column_count'] != 'auto'))
|
||
if columns and box.style['column_rule_width']:
|
||
border_widths = (0, 0, 0, box.style['column_rule_width'])
|
||
for child in box.children[1:]:
|
||
with stacked(context):
|
||
position_x = (child.position_x - (
|
||
box.style['column_rule_width'] +
|
||
box.style['column_gap']) / 2)
|
||
border_box = (
|
||
position_x, child.position_y,
|
||
box.style['column_rule_width'], box.height)
|
||
clip_border_segment(
|
||
context, enable_hinting,
|
||
box.style['column_rule_style'],
|
||
box.style['column_rule_width'], 'left', border_box,
|
||
border_widths)
|
||
draw_rect_border(
|
||
context, border_box, border_widths,
|
||
box.style['column_rule_style'], styled_color(
|
||
box.style['column_rule_style'],
|
||
get_color(box.style, 'column_rule_color'), 'left'))
|
||
|
||
# The box is hidden, easy.
|
||
if box.style['visibility'] != 'visible':
|
||
draw_column_border()
|
||
return
|
||
|
||
widths = [getattr(box, 'border_%s_width' % side) for side in SIDES]
|
||
|
||
# No border, return early.
|
||
if all(width == 0 for width in widths):
|
||
draw_column_border()
|
||
return
|
||
|
||
colors = [get_color(box.style, 'border_%s_color' % side) for side in SIDES]
|
||
styles = [
|
||
colors[i].alpha and box.style['border_%s_style' % side]
|
||
for (i, side) in enumerate(SIDES)]
|
||
|
||
# The 4 sides are solid or double, and they have the same color. Oh yeah!
|
||
# We can draw them so easily!
|
||
if set(styles) in (set(('solid',)), set(('double',))) and (
|
||
len(set(colors)) == 1):
|
||
draw_rounded_border(context, box, styles[0], colors[0])
|
||
draw_column_border()
|
||
return
|
||
|
||
# We're not smart enough to find a good way to draw the borders :/. We must
|
||
# draw them side by side.
|
||
for side, width, color, style in zip(SIDES, widths, colors, styles):
|
||
if width == 0 or not color:
|
||
continue
|
||
with stacked(context):
|
||
clip_border_segment(
|
||
context, enable_hinting, style, width, side,
|
||
box.rounded_border_box()[:4], widths,
|
||
box.rounded_border_box()[4:])
|
||
draw_rounded_border(
|
||
context, box, style, styled_color(style, color, side))
|
||
|
||
draw_column_border()
|
||
|
||
|
||
def clip_border_segment(context, enable_hinting, style, width, side,
|
||
border_box, border_widths=None, radii=None):
|
||
"""Clip one segment of box border.
|
||
|
||
The strategy is to remove the zones not needed because of the style or the
|
||
side before painting.
|
||
|
||
"""
|
||
if enable_hinting and style != 'dotted' and (
|
||
# Borders smaller than 1 device unit would disappear
|
||
# without anti-aliasing.
|
||
hypot(*context.user_to_device(width, 0)) >= 1 and
|
||
hypot(*context.user_to_device(0, width)) >= 1):
|
||
# Avoid an artifact in the corner joining two solid borders
|
||
# of the same color.
|
||
context.set_antialias(cairo.ANTIALIAS_NONE)
|
||
|
||
bbx, bby, bbw, bbh = border_box
|
||
(tlh, tlv), (trh, trv), (brh, brv), (blh, blv) = radii or 4 * ((0, 0),)
|
||
bt, br, bb, bl = border_widths or 4 * (width,)
|
||
|
||
def transition_point(x1, y1, x2, y2):
|
||
"""Get the point use for border transition.
|
||
|
||
The extra boolean returned is ``True`` if the point is in the padding
|
||
box (ie. the padding box is rounded).
|
||
|
||
This point is not specified. We must be sure to be inside the rounded
|
||
padding box, and in the zone defined in the "transition zone" allowed
|
||
by the specification. We chose the corner of the transition zone. It's
|
||
easy to get and gives quite good results, but it seems to be different
|
||
from what other browsers do.
|
||
|
||
"""
|
||
return (
|
||
((x1, y1), True) if abs(x1) > abs(x2) and abs(y1) > abs(y2)
|
||
else ((x2, y2), False))
|
||
|
||
def corner_half_length(a, b):
|
||
"""Return the length of the half of one ellipsis corner.
|
||
|
||
Inspired by [Ramanujan, S., "Modular Equations and Approximations to
|
||
pi" Quart. J. Pure. Appl. Math., vol. 45 (1913-1914), pp. 350-372],
|
||
wonderfully explained by Dr Rob.
|
||
|
||
http://mathforum.org/dr.math/faq/formulas/
|
||
|
||
"""
|
||
x = (a - b) / (a + b)
|
||
return pi / 8 * (a + b) * (
|
||
1 + 3 * x ** 2 / (10 + sqrt(4 - 3 * x ** 2)))
|
||
|
||
if side == 'top':
|
||
(px1, py1), rounded1 = transition_point(tlh, tlv, bl, bt)
|
||
(px2, py2), rounded2 = transition_point(-trh, trv, -br, bt)
|
||
width = bt
|
||
way = 1
|
||
angle = 1
|
||
main_offset = bby
|
||
elif side == 'right':
|
||
(px1, py1), rounded1 = transition_point(-trh, trv, -br, bt)
|
||
(px2, py2), rounded2 = transition_point(-brh, -brv, -br, -bb)
|
||
width = br
|
||
way = 1
|
||
angle = 2
|
||
main_offset = bbx + bbw
|
||
elif side == 'bottom':
|
||
(px1, py1), rounded1 = transition_point(blh, -blv, bl, -bb)
|
||
(px2, py2), rounded2 = transition_point(-brh, -brv, -br, -bb)
|
||
width = bb
|
||
way = -1
|
||
angle = 3
|
||
main_offset = bby + bbh
|
||
elif side == 'left':
|
||
(px1, py1), rounded1 = transition_point(tlh, tlv, bl, bt)
|
||
(px2, py2), rounded2 = transition_point(blh, -blv, bl, -bb)
|
||
width = bl
|
||
way = -1
|
||
angle = 4
|
||
main_offset = bbx
|
||
|
||
if side in ('top', 'bottom'):
|
||
a1, b1 = px1 - bl / 2, way * py1 - width / 2
|
||
a2, b2 = -px2 - br / 2, way * py2 - width / 2
|
||
line_length = bbw - px1 + px2
|
||
length = bbw
|
||
context.move_to(bbx + bbw, main_offset)
|
||
context.rel_line_to(-bbw, 0)
|
||
context.rel_line_to(px1, py1)
|
||
context.rel_line_to(-px1 + bbw + px2, -py1 + py2)
|
||
elif side in ('left', 'right'):
|
||
a1, b1 = -way * px1 - width / 2, py1 - bt / 2
|
||
a2, b2 = -way * px2 - width / 2, -py2 - bb / 2
|
||
line_length = bbh - py1 + py2
|
||
length = bbh
|
||
context.move_to(main_offset, bby + bbh)
|
||
context.rel_line_to(0, -bbh)
|
||
context.rel_line_to(px1, py1)
|
||
context.rel_line_to(-px1 + px2, -py1 + bbh + py2)
|
||
|
||
context.set_fill_rule(cairo.FILL_RULE_EVEN_ODD)
|
||
if style in ('dotted', 'dashed'):
|
||
dash = width if style == 'dotted' else 3 * width
|
||
if rounded1 or rounded2:
|
||
# At least one of the two corners is rounded
|
||
chl1 = corner_half_length(a1, b1)
|
||
chl2 = corner_half_length(a2, b2)
|
||
length = line_length + chl1 + chl2
|
||
dash_length = round(length / dash)
|
||
if rounded1 and rounded2:
|
||
# 2x dashes
|
||
dash = length / (dash_length + dash_length % 2)
|
||
else:
|
||
# 2x - 1/2 dashes
|
||
dash = length / (dash_length + dash_length % 2 - 0.5)
|
||
dashes1 = int(ceil((chl1 - dash / 2) / dash))
|
||
dashes2 = int(ceil((chl2 - dash / 2) / dash))
|
||
line = int(floor(line_length / dash))
|
||
|
||
def draw_dots(dashes, line, way, x, y, px, py, chl):
|
||
if not dashes:
|
||
return line + 1, 0
|
||
for i in range(0, dashes, 2):
|
||
i += 0.5 # half dash
|
||
angle1 = (
|
||
((2 * angle - way) + i * way * dash / chl) /
|
||
4 * pi)
|
||
angle2 = (min if way > 0 else max)(
|
||
((2 * angle - way) + (i + 1) * way * dash / chl) /
|
||
4 * pi,
|
||
angle * pi / 2)
|
||
if side in ('top', 'bottom'):
|
||
context.move_to(x + px, main_offset + py)
|
||
context.line_to(
|
||
x + px - way * px * 1 / tan(angle2),
|
||
main_offset)
|
||
context.line_to(
|
||
x + px - way * px * 1 / tan(angle1),
|
||
main_offset)
|
||
elif side in ('left', 'right'):
|
||
context.move_to(main_offset + px, y + py)
|
||
context.line_to(
|
||
main_offset,
|
||
y + py + way * py * tan(angle2))
|
||
context.line_to(
|
||
main_offset,
|
||
y + py + way * py * tan(angle1))
|
||
if angle2 == angle * pi / 2:
|
||
offset = (angle1 - angle2) / ((
|
||
((2 * angle - way) + (i + 1) * way * dash / chl) /
|
||
4 * pi) - angle1)
|
||
line += 1
|
||
break
|
||
else:
|
||
offset = 1 - (
|
||
(angle * pi / 2 - angle2) / (angle2 - angle1))
|
||
return line, offset
|
||
|
||
line, offset = draw_dots(
|
||
dashes1, line, way, bbx, bby, px1, py1, chl1)
|
||
line = draw_dots(
|
||
dashes2, line, -way, bbx + bbw, bby + bbh, px2, py2, chl2)[0]
|
||
|
||
if line_length > 1e-6:
|
||
for i in range(0, line, 2):
|
||
i += offset
|
||
if side in ('top', 'bottom'):
|
||
x1 = max(bbx + px1 + i * dash, bbx + px1)
|
||
x2 = min(bbx + px1 + (i + 1) * dash, bbx + bbw + px2)
|
||
y1 = main_offset - (width if way < 0 else 0)
|
||
y2 = y1 + width
|
||
elif side in ('left', 'right'):
|
||
y1 = max(bby + py1 + i * dash, bby + py1)
|
||
y2 = min(bby + py1 + (i + 1) * dash, bby + bbh + py2)
|
||
x1 = main_offset - (width if way > 0 else 0)
|
||
x2 = x1 + width
|
||
context.rectangle(x1, y1, x2 - x1, y2 - y1)
|
||
else:
|
||
# 2x + 1 dashes
|
||
context.clip()
|
||
dash = length / (
|
||
round(length / dash) - (round(length / dash) + 1) % 2) or 1
|
||
for i in range(0, int(round(length / dash)), 2):
|
||
if side == 'top':
|
||
context.rectangle(
|
||
bbx + i * dash, bby, dash, width)
|
||
elif side == 'right':
|
||
context.rectangle(
|
||
bbx + bbw - width, bby + i * dash, width, dash)
|
||
elif side == 'bottom':
|
||
context.rectangle(
|
||
bbx + i * dash, bby + bbh - width, dash, width)
|
||
elif side == 'left':
|
||
context.rectangle(
|
||
bbx, bby + i * dash, width, dash)
|
||
context.clip()
|
||
|
||
|
||
def draw_rounded_border(context, box, style, color):
|
||
context.set_fill_rule(cairo.FILL_RULE_EVEN_ODD)
|
||
rounded_box_path(context, box.rounded_padding_box())
|
||
if style in ('ridge', 'groove'):
|
||
rounded_box_path(context, box.rounded_box_ratio(1 / 2))
|
||
context.set_source_rgba(*color[0])
|
||
context.fill()
|
||
rounded_box_path(context, box.rounded_box_ratio(1 / 2))
|
||
rounded_box_path(context, box.rounded_border_box())
|
||
context.set_source_rgba(*color[1])
|
||
context.fill()
|
||
return
|
||
if style == 'double':
|
||
rounded_box_path(context, box.rounded_box_ratio(1 / 3))
|
||
rounded_box_path(context, box.rounded_box_ratio(2 / 3))
|
||
rounded_box_path(context, box.rounded_border_box())
|
||
context.set_source_rgba(*color)
|
||
context.fill()
|
||
|
||
|
||
def draw_rect_border(context, box, widths, style, color):
|
||
context.set_fill_rule(cairo.FILL_RULE_EVEN_ODD)
|
||
bbx, bby, bbw, bbh = box
|
||
bt, br, bb, bl = widths
|
||
context.rectangle(*box)
|
||
if style in ('ridge', 'groove'):
|
||
context.rectangle(
|
||
bbx + bl / 2, bby + bt / 2,
|
||
bbw - (bl + br) / 2, bbh - (bt + bb) / 2)
|
||
context.set_source_rgba(*color[0])
|
||
context.fill()
|
||
context.rectangle(
|
||
bbx + bl / 2, bby + bt / 2,
|
||
bbw - (bl + br) / 2, bbh - (bt + bb) / 2)
|
||
context.rectangle(
|
||
bbx + bl, bby + bt, bbw - bl - br, bbh - bt - bb)
|
||
context.set_source_rgba(*color[1])
|
||
context.fill()
|
||
return
|
||
if style == 'double':
|
||
context.rectangle(
|
||
bbx + bl / 3, bby + bt / 3,
|
||
bbw - (bl + br) / 3, bbh - (bt + bb) / 3)
|
||
context.rectangle(
|
||
bbx + bl * 2 / 3, bby + bt * 2 / 3,
|
||
bbw - (bl + br) * 2 / 3, bbh - (bt + bb) * 2 / 3)
|
||
context.rectangle(bbx + bl, bby + bt, bbw - bl - br, bbh - bt - bb)
|
||
context.set_source_rgba(*color)
|
||
context.fill()
|
||
|
||
|
||
def draw_outlines(context, box, enable_hinting):
|
||
width = box.style['outline_width']
|
||
color = get_color(box.style, 'outline_color')
|
||
style = box.style['outline_style']
|
||
if box.style['visibility'] == 'visible' and width and color.alpha:
|
||
outline_box = (
|
||
box.border_box_x() - width, box.border_box_y() - width,
|
||
box.border_width() + 2 * width, box.border_height() + 2 * width)
|
||
for side in SIDES:
|
||
with stacked(context):
|
||
clip_border_segment(
|
||
context, enable_hinting, style, width, side, outline_box)
|
||
draw_rect_border(
|
||
context, outline_box, 4 * (width,), style,
|
||
styled_color(style, color, side))
|
||
|
||
if isinstance(box, boxes.ParentBox):
|
||
for child in box.children:
|
||
if isinstance(child, boxes.Box):
|
||
draw_outlines(context, child, enable_hinting)
|
||
|
||
|
||
def draw_collapsed_borders(context, table, enable_hinting):
|
||
"""Draw borders of table cells when they collapse."""
|
||
row_heights = [row.height for row_group in table.children
|
||
for row in row_group.children]
|
||
column_widths = table.column_widths
|
||
if not (row_heights and column_widths):
|
||
# One of the list is empty: don’t bother with empty tables
|
||
return
|
||
row_positions = [row.position_y for row_group in table.children
|
||
for row in row_group.children]
|
||
column_positions = list(table.column_positions)
|
||
grid_height = len(row_heights)
|
||
grid_width = len(column_widths)
|
||
assert grid_width == len(column_positions)
|
||
# Add the end of the last column, but make a copy from the table attr.
|
||
column_positions += [column_positions[-1] + column_widths[-1]]
|
||
# Add the end of the last row. No copy here, we own this list
|
||
row_positions.append(row_positions[-1] + row_heights[-1])
|
||
vertical_borders, horizontal_borders = table.collapsed_border_grid
|
||
if table.children[0].is_header:
|
||
header_rows = len(table.children[0].children)
|
||
else:
|
||
header_rows = 0
|
||
if table.children[-1].is_footer:
|
||
footer_rows = len(table.children[-1].children)
|
||
else:
|
||
footer_rows = 0
|
||
skipped_rows = table.skipped_rows
|
||
if skipped_rows:
|
||
body_rows_offset = skipped_rows - header_rows
|
||
else:
|
||
body_rows_offset = 0
|
||
if header_rows == 0:
|
||
header_rows = -1
|
||
if footer_rows:
|
||
first_footer_row = grid_height - footer_rows - 1
|
||
else:
|
||
first_footer_row = grid_height + 1
|
||
original_grid_height = len(vertical_borders)
|
||
footer_rows_offset = original_grid_height - grid_height
|
||
|
||
def row_number(y, horizontal):
|
||
if y < (header_rows + int(horizontal)):
|
||
return y
|
||
elif y >= (first_footer_row + int(horizontal)):
|
||
return y + footer_rows_offset
|
||
else:
|
||
return y + body_rows_offset
|
||
|
||
segments = []
|
||
|
||
def half_max_width(border_list, yx_pairs, vertical=True):
|
||
result = 0
|
||
for y, x in yx_pairs:
|
||
if (
|
||
(0 <= y < grid_height and 0 <= x <= grid_width)
|
||
if vertical else
|
||
(0 <= y <= grid_height and 0 <= x < grid_width)
|
||
):
|
||
yy = row_number(y, horizontal=not vertical)
|
||
_, (_, width, _) = border_list[yy][x]
|
||
result = max(result, width)
|
||
return result / 2
|
||
|
||
def add_vertical(x, y):
|
||
yy = row_number(y, horizontal=False)
|
||
score, (style, width, color) = vertical_borders[yy][x]
|
||
if width == 0 or color.alpha == 0:
|
||
return
|
||
pos_x = column_positions[x]
|
||
pos_y1 = row_positions[y] - half_max_width(horizontal_borders, [
|
||
(y, x - 1), (y, x)], vertical=False)
|
||
pos_y2 = row_positions[y + 1] + half_max_width(horizontal_borders, [
|
||
(y + 1, x - 1), (y + 1, x)], vertical=False)
|
||
segments.append((
|
||
score, style, width, color, 'left',
|
||
(pos_x - width / 2, pos_y1, 0, pos_y2 - pos_y1)))
|
||
|
||
def add_horizontal(x, y):
|
||
yy = row_number(y, horizontal=True)
|
||
score, (style, width, color) = horizontal_borders[yy][x]
|
||
if width == 0 or color.alpha == 0:
|
||
return
|
||
pos_y = row_positions[y]
|
||
# TODO: change signs for rtl when we support rtl tables?
|
||
pos_x1 = column_positions[x] - half_max_width(vertical_borders, [
|
||
(y - 1, x), (y, x)])
|
||
pos_x2 = column_positions[x + 1] + half_max_width(vertical_borders, [
|
||
(y - 1, x + 1), (y, x + 1)])
|
||
segments.append((
|
||
score, style, width, color, 'top',
|
||
(pos_x1, pos_y - width / 2, pos_x2 - pos_x1, 0)))
|
||
|
||
for x in range(grid_width):
|
||
add_horizontal(x, 0)
|
||
for y in range(grid_height):
|
||
add_vertical(0, y)
|
||
for x in range(grid_width):
|
||
add_vertical(x + 1, y)
|
||
add_horizontal(x, y + 1)
|
||
|
||
# Sort bigger scores last (painted later, on top)
|
||
# Since the number of different scores is expected to be small compared
|
||
# to the number of segments, there should be little changes and Timsort
|
||
# should be closer to O(n) than O(n * log(n))
|
||
segments.sort(key=operator.itemgetter(0))
|
||
|
||
for segment in segments:
|
||
_, style, width, color, side, border_box = segment
|
||
if side == 'top':
|
||
widths = (width, 0, 0, 0)
|
||
else:
|
||
widths = (0, 0, 0, width)
|
||
with stacked(context):
|
||
clip_border_segment(
|
||
context, enable_hinting, style, width, side, border_box,
|
||
widths)
|
||
draw_rect_border(
|
||
context, border_box, widths, style,
|
||
styled_color(style, color, side))
|
||
|
||
|
||
def draw_replacedbox(context, box):
|
||
"""Draw the given :class:`boxes.ReplacedBox` to a ``cairo.context``."""
|
||
if box.style['visibility'] != 'visible' or not box.width or not box.height:
|
||
return
|
||
|
||
draw_width, draw_height, draw_x, draw_y = replaced.replacedbox_layout(box)
|
||
|
||
with stacked(context):
|
||
rounded_box_path(context, box.rounded_content_box())
|
||
context.clip()
|
||
context.translate(draw_x, draw_y)
|
||
box.replacement.draw(
|
||
context, draw_width, draw_height, box.style['image_rendering'])
|
||
|
||
|
||
def draw_inline_level(context, page, box, enable_hinting, offset_x=0,
|
||
text_overflow='clip'):
|
||
if isinstance(box, StackingContext):
|
||
stacking_context = box
|
||
assert isinstance(
|
||
stacking_context.box, (boxes.InlineBlockBox, boxes.InlineFlexBox))
|
||
draw_stacking_context(context, stacking_context, enable_hinting)
|
||
else:
|
||
draw_background(context, box.background, enable_hinting)
|
||
draw_border(context, box, enable_hinting)
|
||
if isinstance(box, (boxes.InlineBox, boxes.LineBox)):
|
||
if isinstance(box, boxes.LineBox):
|
||
text_overflow = box.text_overflow
|
||
for child in box.children:
|
||
if isinstance(child, StackingContext):
|
||
child_offset_x = offset_x
|
||
else:
|
||
child_offset_x = (
|
||
offset_x + child.position_x - box.position_x)
|
||
if isinstance(child, boxes.TextBox):
|
||
draw_text(
|
||
context, child, enable_hinting,
|
||
child_offset_x, text_overflow)
|
||
else:
|
||
draw_inline_level(
|
||
context, page, child, enable_hinting, child_offset_x,
|
||
text_overflow)
|
||
elif isinstance(box, boxes.InlineReplacedBox):
|
||
draw_replacedbox(context, box)
|
||
else:
|
||
assert isinstance(box, boxes.TextBox)
|
||
# Should only happen for list markers
|
||
draw_text(context, box, enable_hinting, offset_x, text_overflow)
|
||
|
||
|
||
def draw_text(context, textbox, enable_hinting, offset_x=0,
|
||
text_overflow='clip'):
|
||
"""Draw ``textbox`` to a ``cairo.Context`` from ``PangoCairo.Context``."""
|
||
# Pango crashes with font-size: 0
|
||
assert textbox.style['font_size']
|
||
|
||
if textbox.style['visibility'] != 'visible':
|
||
return
|
||
|
||
context.move_to(textbox.position_x, textbox.position_y + textbox.baseline)
|
||
context.set_source_rgba(*textbox.style['color'])
|
||
|
||
textbox.pango_layout.reactivate(textbox.style)
|
||
show_first_line(context, textbox, text_overflow)
|
||
|
||
values = textbox.style['text_decoration_line']
|
||
|
||
thickness = textbox.style['font_size'] / 18 # Like other browsers do
|
||
if enable_hinting and thickness < 1:
|
||
thickness = 1
|
||
|
||
color = textbox.style['text_decoration_color']
|
||
if color == 'currentColor':
|
||
color = textbox.style['color']
|
||
|
||
if ('overline' in values or
|
||
'line-through' in values or
|
||
'underline' in values):
|
||
metrics = textbox.pango_layout.get_font_metrics()
|
||
if 'overline' in values:
|
||
draw_text_decoration(
|
||
context, textbox, offset_x,
|
||
textbox.baseline - metrics.ascent + thickness / 2,
|
||
thickness, enable_hinting, color)
|
||
if 'underline' in values:
|
||
draw_text_decoration(
|
||
context, textbox, offset_x,
|
||
textbox.baseline - metrics.underline_position + thickness / 2,
|
||
thickness, enable_hinting, color)
|
||
if 'line-through' in values:
|
||
draw_text_decoration(
|
||
context, textbox, offset_x,
|
||
textbox.baseline - metrics.strikethrough_position,
|
||
thickness, enable_hinting, color)
|
||
|
||
textbox.pango_layout.deactivate()
|
||
|
||
|
||
def draw_wave(context, x, y, width, offset_x, radius):
|
||
context.new_path()
|
||
diameter = 2 * radius
|
||
wave_index = offset_x // diameter
|
||
remain = offset_x - wave_index * diameter
|
||
|
||
while width > 0:
|
||
up = (wave_index % 2 == 0)
|
||
center_x = x - remain + radius
|
||
alpha1 = (1 + remain / diameter) * pi
|
||
alpha2 = (1 + min(1, width / diameter)) * pi
|
||
|
||
if up:
|
||
context.arc(center_x, y, radius, alpha1, alpha2)
|
||
else:
|
||
context.arc_negative(
|
||
center_x, y, radius, -alpha1, -alpha2)
|
||
|
||
x += diameter - remain
|
||
width -= diameter - remain
|
||
remain = 0
|
||
wave_index += 1
|
||
|
||
|
||
def draw_text_decoration(context, textbox, offset_x, offset_y, thickness,
|
||
enable_hinting, color):
|
||
"""Draw text-decoration of ``textbox`` to a ``cairo.Context``."""
|
||
style = textbox.style['text_decoration_style']
|
||
with stacked(context):
|
||
if enable_hinting:
|
||
context.set_antialias(cairo.ANTIALIAS_NONE)
|
||
context.set_source_rgba(*color)
|
||
context.set_line_width(thickness)
|
||
|
||
if style == 'dashed':
|
||
context.set_dash([5 * thickness], offset=offset_x)
|
||
elif style == 'dotted':
|
||
context.set_dash([thickness], offset=offset_x)
|
||
|
||
if style == 'wavy':
|
||
draw_wave(
|
||
context,
|
||
textbox.position_x, textbox.position_y + offset_y,
|
||
textbox.width, offset_x, 0.75 * thickness)
|
||
else:
|
||
context.move_to(textbox.position_x, textbox.position_y + offset_y)
|
||
context.rel_line_to(textbox.width, 0)
|
||
|
||
if style == 'double':
|
||
delta = 2 * thickness
|
||
context.move_to(
|
||
textbox.position_x, textbox.position_y + offset_y + delta)
|
||
context.rel_line_to(textbox.width, 0)
|
||
|
||
context.stroke()
|