Add support for text annotations

Support PDF annotations via the TextAnnotation raw directive in this
format:

    .. raw:: pdf

        TextAnnotation "My content here"

This is useful for speaker notes in Présentation.

rst2pdf/flowables.py

@@ -486,6 +486,22 @@ def draw(self):
     def wrap(self, aW, aH):
         return 0,0
 
+class TextAnnotation(Flowable):
+    """Add text annotation flowable"""
+
+    def __init__(self, *args):
+        if len(args) < 1:
+            args = [None, 1] # No transition
+        self.annotationText = args[0].lstrip('"').rstrip('"')
+
+    def wrap(self, w, h):
+        return 0, 0
+
+    def draw(self):
+        # Format of Reportlab's textAnnotation():
+        # textAnnotation("Your content", Rect=[x_begin, y_begin, x_end, y_end], relative=1)
+        self.canv.textAnnotation(self.annotationText, [-1, -1, -1, -1], 1)
+
 class Transition(Flowable):
     """Wrap canvas.setPageTransition.
 

rst2pdf/tests/input/textannotation.txt

@@ -0,0 +1,5 @@
+The `TextAnnotation` directive add an annotation to the PDF
+
+.. raw:: pdf
+
+    TextAnnotation "This is an annotation"

rst2pdf/tests/md5/textannotation.json

@@ -0,0 +1,9 @@
+bad_md5 = [
+        'sentinel'
+]
+
+good_md5 = [
+        '15759227f97f019679a39c0d893e3c68',
+        'sentinel'
+]
+

rst2pdf/utils.py

@@ -17,8 +17,13 @@ def parseRaw(data, node):
     Supported (can add others on request):
 
     * PageBreak
-
+    * EvenPageBreak
+    * OddPageBreak
+    * FrameBreak
     * Spacer width, height
+    * Transition
+    * SetPageCounter
+    * TextAnnotation "text of annotation"
 
     """
     elements = []
@@ -57,6 +62,8 @@ def parseRaw(data, node):
             elements.append(Transition(*tokens[1:]))
         elif command == 'SetPageCounter':
             elements.append(flowables.PageCounter(*tokens[1:]))
+        elif command == 'TextAnnotation':
+            elements.append(TextAnnotation(*tokens[1:]))
         else:
             log.error('Unknown command %s in raw pdf directive [%s]'%(command,nodeid(node)))
     return elements