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app/.venv/Lib/site-packages/weasyprint/layout/percent.py

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+"""Resolve percentages into fixed values."""
+
+from math import inf
+
+from ..formatting_structure import boxes
+
+
+def percentage(value, refer_to):
+    """Return the percentage of the reference value, or the value unchanged.
+
+    ``refer_to`` is the length for 100%. If ``refer_to`` is not a number, it
+    just replaces percentages.
+
+    """
+    if value is None or value == 'auto':
+        return value
+    elif value.unit == 'px':
+        return value.value
+    else:
+        assert value.unit == '%'
+        return refer_to * value.value / 100
+
+
+def resolve_one_percentage(box, property_name, refer_to,
+                           main_flex_direction=None):
+    """Set a used length value from a computed length value.
+
+    ``refer_to`` is the length for 100%. If ``refer_to`` is not a number, it
+    just replaces percentages.
+
+    """
+    # box.style has computed values
+    value = box.style[property_name]
+    # box attributes are used values
+    percent = percentage(value, refer_to)
+    setattr(box, property_name, percent)
+    if property_name in ('min_width', 'min_height') and percent == 'auto':
+        if (main_flex_direction is None or
+                property_name != (f'min_{main_flex_direction}')):
+            setattr(box, property_name, 0)
+
+
+def resolve_position_percentages(box, containing_block):
+    cb_width, cb_height = containing_block
+    resolve_one_percentage(box, 'left', cb_width)
+    resolve_one_percentage(box, 'right', cb_width)
+    resolve_one_percentage(box, 'top', cb_height)
+    resolve_one_percentage(box, 'bottom', cb_height)
+
+
+def resolve_percentages(box, containing_block, main_flex_direction=None):
+    """Set used values as attributes of the box object."""
+    if isinstance(containing_block, boxes.Box):
+        # cb is short for containing block
+        cb_width = containing_block.width
+        cb_height = containing_block.height
+    else:
+        cb_width, cb_height = containing_block
+    if isinstance(box, boxes.PageBox):
+        maybe_height = cb_height
+    else:
+        maybe_height = cb_width
+    resolve_one_percentage(box, 'margin_left', cb_width)
+    resolve_one_percentage(box, 'margin_right', cb_width)
+    resolve_one_percentage(box, 'margin_top', maybe_height)
+    resolve_one_percentage(box, 'margin_bottom', maybe_height)
+    resolve_one_percentage(box, 'padding_left', cb_width)
+    resolve_one_percentage(box, 'padding_right', cb_width)
+    resolve_one_percentage(box, 'padding_top', maybe_height)
+    resolve_one_percentage(box, 'padding_bottom', maybe_height)
+    resolve_one_percentage(box, 'width', cb_width)
+    resolve_one_percentage(box, 'min_width', cb_width, main_flex_direction)
+    resolve_one_percentage(box, 'max_width', cb_width, main_flex_direction)
+
+    # XXX later: top, bottom, left and right on positioned elements
+
+    if cb_height == 'auto':
+        # Special handling when the height of the containing block
+        # depends on its content.
+        height = box.style['height']
+        if height == 'auto' or height.unit == '%':
+            box.height = 'auto'
+        else:
+            assert height.unit == 'px'
+            box.height = height.value
+        resolve_one_percentage(box, 'min_height', 0, main_flex_direction)
+        resolve_one_percentage(box, 'max_height', inf, main_flex_direction)
+    else:
+        resolve_one_percentage(box, 'height', cb_height)
+        resolve_one_percentage(
+            box, 'min_height', cb_height, main_flex_direction)
+        resolve_one_percentage(
+            box, 'max_height', cb_height, main_flex_direction)
+
+    collapse = box.style['border_collapse'] == 'collapse'
+    # Used value == computed value
+    for side in ('top', 'right', 'bottom', 'left'):
+        prop = f'border_{side}_width'
+        # border-{side}-width would have been resolved
+        # during border conflict resolution for collapsed-borders
+        if not (collapse and hasattr(box, prop)):
+            setattr(box, prop, box.style[prop])
+
+    # Shrink *content* widths and heights according to box-sizing
+    # Thanks heavens and the spec: Our validator rejects negative values
+    # for padding and border-width
+    if box.style['box_sizing'] == 'border-box':
+        horizontal_delta = (
+            box.padding_left + box.padding_right +
+            box.border_left_width + box.border_right_width)
+        vertical_delta = (
+            box.padding_top + box.padding_bottom +
+            box.border_top_width + box.border_bottom_width)
+    elif box.style['box_sizing'] == 'padding-box':
+        horizontal_delta = box.padding_left + box.padding_right
+        vertical_delta = box.padding_top + box.padding_bottom
+    else:
+        assert box.style['box_sizing'] == 'content-box'
+        horizontal_delta = 0
+        vertical_delta = 0
+
+    # Keep at least min_* >= 0 to prevent funny output in case box.width or
+    # box.height become negative.
+    # Restricting max_* seems reasonable, too.
+    if horizontal_delta > 0:
+        if box.width != 'auto':
+            box.width = max(0, box.width - horizontal_delta)
+        box.max_width = max(0, box.max_width - horizontal_delta)
+        if box.min_width != 'auto':
+            box.min_width = max(0, box.min_width - horizontal_delta)
+    if vertical_delta > 0:
+        if box.height != 'auto':
+            box.height = max(0, box.height - vertical_delta)
+        box.max_height = max(0, box.max_height - vertical_delta)
+        if box.min_height != 'auto':
+            box.min_height = max(0, box.min_height - vertical_delta)
+
+
+def resolve_radii_percentages(box):
+    for corner in ('top_left', 'top_right', 'bottom_right', 'bottom_left'):
+        property_name = f'border_{corner}_radius'
+        rx, ry = box.style[property_name]
+
+        # Short track for common case
+        if (0, 'px') in (rx, ry):
+            setattr(box, property_name, (0, 0))
+            continue
+
+        for side in corner.split('_'):
+            if side in box.remove_decoration_sides:
+                setattr(box, property_name, (0, 0))
+                break
+        else:
+            rx = percentage(rx, box.border_width())
+            ry = percentage(ry, box.border_height())
+            setattr(box, property_name, (rx, ry))