fix: Improve the position of the conditions on the edges

ansibleplaybookgrapher/postprocessor.py

@@ -15,10 +15,15 @@
 import os
 from typing import Dict
 
+from ansible.utils.display import Display
 from lxml import etree
+from svg.path import parse_path
 
 from ansibleplaybookgrapher.graph import PlaybookNode
 
+display = Display()
+DISPLAY_PREFIX = "postprocessor:"
+
 JQUERY = "https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"
 SVG_NAMESPACE = "http://www.w3.org/2000/svg"
 
@@ -149,6 +154,32 @@ def _insert_graph_representation(self, graph_representation: PlaybookNode):
 
                 element.append(root_subelement)
 
+    def _get_text_path_start_offset(self, path_element, text: str) -> str:
+        """
+        Get the start offset where the edge label should begin
+        :param path_element:
+        :param text:
+        :return:
+        """
+        # Get Bézier curve
+        path_segments = parse_path(path_element.get("d"))
+        # FIXME: apply the translation to the segments ?
+        #  TRANSLATE_PATTERN = re.compile(".*translate\((?P<x>[+-]?[0-9]*[.]?[0-9]+) (?P<y>[+-]?[0-9]*[.]?[0-9]+)\).*")
+        #  transform_attribute = self.root.xpath("//*[@id='graph0']", namespaces={"ns": SVG_NAMESPACE})[0].get("transform")
+
+        # The segments usually contain 3 elements: One MoveTo and one or two CubicBezier objects.
+        # This is relatively slow to compute. Decreasing the "error" will drastically slow down the post-processing
+        segment_length = path_segments.length(error=1e-4)
+        text_length = len(text)
+        # We put the label closer to the target node
+        offset_factor = 0.76
+
+        start_offset = segment_length * offset_factor - text_length
+        msg = f"{DISPLAY_PREFIX} {len(path_segments)} segment(s) found for the path '{path_element.get('id')}', "
+        msg += f"segment_length={segment_length}, start_offset={start_offset}, text_length={text_length}"
+        display.vvvvv(msg)
+        return str(start_offset)
+
     def _curve_text_on_edges(self):
         """
         Update the text on each edge to curve it based on the edge
@@ -160,22 +191,34 @@ def _curve_text_on_edges(self):
         )
 
         for edge in edge_elements:
-            path_element = edge.find(".//path", namespaces=self.root.nsmap)
+            path_elements = edge.findall(".//path", namespaces=self.root.nsmap)
+            display.vvvvv(
+                f"{DISPLAY_PREFIX} {len(path_elements)} path(s) found on the edge '{edge.get('id')}'"
+            )
             text_element = edge.find(".//text", namespaces=self.root.nsmap)
+
+            # Define an ID for the path so that we can reference it explicitly
             path_id = f"path_{edge.get('id')}"
+            # Even though we may have more than one path, we only care about a single on.
+            #  We have more than one path (edge) pointing to a single task if role containing the task is used more than
+            #   once.
+            path_element = path_elements[0]
             path_element.set("id", path_id)
 
-            # Create a curved textPath
+            # Create a curved textPath: the text will follow the path
             text_path = etree.Element("textPath")
             text_path.set("{http://www.w3.org/1999/xlink}href", f"#{path_id}")
-            text_path.set("text-anchor", "middle")
-            text_path.set("startOffset", "50%")
             text_path.text = text_element.text
+
+            offset = self._get_text_path_start_offset(path_element, text_path.text)
+            text_path.set("startOffset", offset)
+
             text_element.append(text_path)
 
-            # Move a little the text
-            text_element.set("dy", "-0.5%")
-            # Remove unnecessary attributes
-            text_element.attrib.pop("x")
-            text_element.attrib.pop("y")
+            # The more paths we have, the more we move the text from the path
+            dy = -0.2 - (len(path_elements) - 1) * 0.4
+            text_element.set("dy", f"{dy}%")
+            # Remove unnecessary attributes and clear the text
+            text_element.attrib.pop("x", "")
+            text_element.attrib.pop("y", "")
             text_element.text = None

ansibleplaybookgrapher/utils.py

@@ -41,7 +41,7 @@ def convert_when_to_str(when: List) -> str:
 
     # Convert each element in the list to str
     when_to_str = list(map(str, when))
-    return f"[when: {' and '.join(when_to_str)}]"
+    return f"[when: {' and '.join(when_to_str)}]".strip().replace("\n", "")
 
 
 def hash_value(value: str) -> str:

requirements.txt

@@ -2,3 +2,4 @@ ansible-core>=2.11,<2.13
 graphviz>=0.18,<1
 colour<1
 lxml<5
+svg.path<7