Support percentages for opacity

Fix #1986.

tests/draw/svg/test_opacity.py

@@ -31,7 +31,7 @@ def test_fill_opacity(assert_same_renderings):
     assert_same_renderings(
         opacity_source % '''
             <rect x="2" y="2" width="5" height="5"
-                  fill="blue" opacity="0.5" />
+                  fill="blue" opacity="50%" />
             <rect x="2" y="2" width="5" height="5" stroke-width="2"
                   stroke="lime" fill="transparent" />
         ''',
@@ -59,7 +59,7 @@ def test_stroke_opacity(assert_same_renderings):
         ''',
         opacity_source % '''
             <rect x="2" y="2" width="5" height="5" stroke-width="2"
-                  stroke="lime" fill="blue" stroke-opacity="0.5" />
+                  stroke="lime" fill="blue" stroke-opacity="50%" />
         ''',
     )
 
@@ -82,7 +82,6 @@ def test_stroke_fill_opacity(assert_same_renderings):
     )
 
 
-@pytest.mark.xfail
 @assert_no_logs
 def test_pattern_gradient_stroke_fill_opacity(assert_same_renderings):
     assert_same_renderings(
@@ -141,6 +140,6 @@ def test_translate_opacity(assert_same_renderings):
         ''',
         opacity_source % '''
             <rect x="2" y="2" width="5" height="5"
-                  fill="blue" opacity="0.5" />
+                  fill="blue" opacity="50%" />
         ''',
     )

tests/draw/test_opacity.py

@@ -11,23 +11,26 @@
 
 
 @assert_no_logs
-def test_opacity_1(assert_same_renderings):
+def test_opacity_zero(assert_same_renderings):
     assert_same_renderings(
         opacity_source % '<div></div>',
         opacity_source % '<div></div><div style="opacity: 0"></div>',
+        opacity_source % '<div></div><div style="opacity: 0%"></div>',
     )
 
 
 @assert_no_logs
-def test_opacity_2(assert_same_renderings):
+def test_opacity_normal_range(assert_same_renderings):
     assert_same_renderings(
         opacity_source % '<div style="background: rgb(102, 102, 102)"></div>',
         opacity_source % '<div style="opacity: 0.6"></div>',
+        opacity_source % '<div style="opacity: 60%"></div>',
+        opacity_source % '<div style="opacity: 60.0%"></div>',
     )
 
 
 @assert_no_logs
-def test_opacity_3(assert_same_renderings):
+def test_opacity_nested(assert_same_renderings):
     assert_same_renderings(
         opacity_source % '<div style="background: rgb(102, 102, 102)"></div>',
         opacity_source % '<div style="opacity: 0.6"></div>',
@@ -37,3 +40,21 @@ def test_opacity_3(assert_same_renderings):
           </div>
         ''',  # 0.9 * 0.666666 == 0.6
     )
+
+
+@assert_no_logs
+def test_opacity_percent_clamp_down(assert_same_renderings):
+    assert_same_renderings(
+        opacity_source % '<div></div>',
+        opacity_source % '<div style="opacity: 1.2"></div>',
+        opacity_source % '<div style="opacity: 120%"></div>',
+    )
+
+
+@assert_no_logs
+def test_opacity_percent_clamp_up(assert_same_renderings):
+    assert_same_renderings(
+        opacity_source % '<div></div>',
+        opacity_source % '<div></div><div style="opacity: -0.2"></div>',
+        opacity_source % '<div></div><div style="opacity: -20%"></div>',
+    )

weasyprint/css/validation/properties.py

@@ -1029,6 +1029,8 @@ def opacity(token):
     """Validation for the ``opacity`` property."""
     if token.type == 'number':
         return min(1, max(0, token.value))
+    if token.type == 'percentage':
+        return min(1, max(0, token.value / 100))
 
 
 @property()

weasyprint/svg/__init__.py

@@ -19,7 +19,8 @@
 from .shapes import circle, ellipse, line, polygon, polyline, rect
 from .text import text
 from .utils import (
-    PointError, color, normalize, parse_url, preserve_ratio, size, transform)
+    PointError, alpha_value, color, normalize, parse_url, preserve_ratio, size,
+    transform)
 
 TAGS = {
     'a': text,
@@ -412,7 +413,7 @@ def draw_node(self, node, font_size, fill_stroke=True):
         self.transform(node.get('transform'), font_size)
 
         # Create substream for opacity
-        opacity = float(node.get('opacity', 1))
+        opacity = alpha_value(node.get('opacity', 1))
         if fill_stroke and 0 <= opacity < 1:
             original_streams.append(self.stream)
             box = self.calculate_bounding_box(node, font_size)
@@ -662,7 +663,7 @@ def fill_stroke(self, node, font_size, text=False):
 
         # Get fill data
         fill_source, fill_color = self.get_paint(node.get('fill', 'black'))
-        fill_opacity = float(node.get('fill-opacity', 1))
+        fill_opacity = alpha_value(node.get('fill-opacity', 1))
         fill_drawn = draw_gradient_or_pattern(
             self, node, fill_source, font_size, fill_opacity, stroke=False)
         if fill_color and not fill_drawn:
@@ -673,7 +674,7 @@ def fill_stroke(self, node, font_size, text=False):
 
         # Get stroke data
         stroke_source, stroke_color = self.get_paint(node.get('stroke'))
-        stroke_opacity = float(node.get('stroke-opacity', 1))
+        stroke_opacity = alpha_value(node.get('stroke-opacity', 1))
         stroke_drawn = draw_gradient_or_pattern(
             self, node, stroke_source, font_size, stroke_opacity, stroke=True)
         if stroke_color and not stroke_drawn:

weasyprint/svg/defs.py

@@ -5,7 +5,7 @@
 
 from ..matrix import Matrix
 from .bounding_box import is_valid_bounding_box
-from .utils import color, parse_url, size, transform
+from .utils import alpha_value, color, parse_url, size, transform
 
 
 def use(svg, node, font_size):
@@ -83,7 +83,7 @@ def draw_gradient(svg, node, gradient, font_size, opacity, stroke):
         positions.append(max(
             positions[-1] if positions else 0,
             size(child.get('offset'), font_size, 1)))
-        stop_opacity = float(child.get('stop-opacity', 1)) * opacity
+        stop_opacity = alpha_value(child.get('stop-opacity', 1)) * opacity
         stop_color = color(child.get('stop-color', 'black'))
         if stop_opacity < 1:
             stop_color = tuple(

weasyprint/svg/utils.py

@@ -57,6 +57,17 @@ def size(string, font_size=None, percentage_reference=None):
     return 0
 
 
+def alpha_value(value):
+    """Return opacity between 0 and 1 from str, number or percentage."""
+    ratio = 1
+    if isinstance(value, str):
+        value = value.strip()
+        if value.endswith('%'):
+            ratio = 100
+            value = value[:-1].strip()
+    return min(1, max(0, float(value) / ratio))
+
+
 def point(svg, string, font_size):
     """Pop first two size values from a string."""
     match = re.match('(.*?) (.*?)(?: |$)', string)