support subgraphs

2 files changed, 824 insertions, 14 deletions

diff --git a/src/attributes/mod.rs b/src/attributes/mod.rs
index ea4427a..450440e 100644
--- a/src/attributes/mod.rs
+++ b/src/attributes/mod.rs
@@ -330,17 +330,12 @@ pub trait AttributeStatement<'a> {
         if self.get_attributes().is_empty() {
             return String::from("");
         }
-        let mut dot_string = format!("{} [", self.get_attribute_statement_type());
-        let attributes = &self.get_attributes();
-        let mut iter = attributes.iter();
-        let first = iter.next().unwrap();
-        dot_string.push_str(format!("{}={}", first.0, first.1.dot_string()).as_str());
-        for (key, value) in iter {
-            dot_string.push_str(", ");
-            dot_string.push_str(format!("{}={}", key, value.dot_string()).as_str());
-        }
-        dot_string.push_str("];");
-        dot_string.to_string()
+
+        format!(
+            "{}{};",
+            self.get_attribute_statement_type(),
+            fmt_attributes(self.get_attributes())
+        )
     }
 }
 
@@ -399,6 +394,14 @@ pub trait GraphAttributes<'a> {
         self.add_attribute("clusterrank", AttributeText::from(cluster_rank))
     }
 
+    /// Basic drawing color for graphics, not text. For the latter, use the fontcolor attribute.
+    /// If any fraction is used, the colors are drawn in series, with each color being given
+    /// roughly its specified fraction of the edge.
+    fn color(&mut self, color: Color<'a>) -> &mut Self {
+        Attributes::color(self.get_attributes_mut(), color);
+        self
+    }
+
     /// This attribute specifies a color scheme namespace: the context for interpreting color names.
     /// In particular, if a color value has form "xxx" or "//xxx", then the color xxx will be evaluated
     /// according to the current color scheme. If no color scheme is set, the standard X11 naming is used.
@@ -1159,6 +1162,813 @@ impl Attributes {
     }
 }
 
+pub trait NodeAttributes<'a> {
+    // TODO: constrain
+    /// Indicates the preferred area for a node or empty cluster when laid out by patchwork.
+    /// default: 1.0, minimum: >0
+    fn area(&mut self, area: f32) -> &mut Self {
+        self.add_attribute("area", AttributeText::from(area))
+    }
+
+    /// Classnames to attach to the node’s SVG element.
+    /// Combine with stylesheet for styling SVG output using CSS classnames.
+    /// Multiple space-separated classes are supported.
+    fn class(&mut self, class: String) -> &mut Self {
+        Attributes::class(self.get_attributes_mut(), class);
+        self
+    }
+
+    /// Basic drawing color for graphics, not text. For the latter, use the fontcolor attribute.
+    fn color(&mut self, color: Color<'a>) -> &mut Self {
+        Attributes::color(self.get_attributes_mut(), color);
+        self
+    }
+
+    /// This attribute specifies a color scheme namespace: the context for interpreting color names.
+    /// In particular, if a color value has form "xxx" or "//xxx", then the color xxx will be evaluated
+    /// according to the current color scheme. If no color scheme is set, the standard X11 naming is used.
+    /// For example, if colorscheme=bugn9, then color=7 is interpreted as color="/bugn9/7".
+    fn color_scheme(&mut self, color_scheme: String) -> &mut Self {
+        Attributes::color_scheme(self.get_attributes_mut(), color_scheme);
+        self
+    }
+
+    /// Comments are inserted into output. Device-dependent
+    fn comment(&mut self, comment: String) -> &mut Self {
+        Attributes::comment(self.get_attributes_mut(), comment);
+        self
+    }
+
+    /// Distortion factor for shape=polygon.
+    /// Positive values cause top part to be larger than bottom; negative values do the opposite.
+    fn distortion(&mut self, distortion: f32) -> &mut Self {
+        self.add_attribute("distortion", AttributeText::from(distortion))
+    }
+
+    /// Color used to fill the background of a node or cluster assuming style=filled, or a filled arrowhead.
+    fn fill_color(&mut self, fill_color: Color<'a>) -> &mut Self {
+        Attributes::fill_color(self.get_attributes_mut(), fill_color);
+        self
+    }
+
+    /// Color used to fill the background, with a gradient, of a node or cluster assuming
+    /// style=filled, or a filled arrowhead.
+    fn fill_color_with_colorlist(&mut self, fill_colors: ColorList<'a>) -> &mut Self {
+        Attributes::fill_color_with_colorlist(self.get_attributes_mut(), fill_colors);
+        self
+    }
+
+    /// Color used to fill the background, with a gradient, of a node or cluster assuming
+    /// style=filled, or a filled arrowhead.
+    /// TODO: example
+    fn fill_color_with_iter<I>(&mut self, fill_colors: I) -> &mut Self
+    where
+        I: IntoIterator,
+        I::Item: IntoWeightedColor<'a>,
+    {
+        Attributes::fill_color_with_iter(self.get_attributes_mut(), fill_colors);
+        self
+    }
+
+    /// If true, the node size is specified by the values of the width and height attributes only and
+    /// is not expanded to contain the text label.
+    /// There will be a warning if the label (with margin) cannot fit within these limits.
+    /// If false, the size of a node is determined by smallest width and height needed to contain its label
+    /// and image, if any, with a margin specified by the margin attribute.
+    fn fixed_size(&mut self, fixed_size: bool) -> &mut Self {
+        self.add_attribute("fixedsize", AttributeText::from(fixed_size))
+    }
+
+    /// Color used for text.
+    fn font_color(&mut self, font_color: Color<'a>) -> &mut Self {
+        Attributes::font_color(self.get_attributes_mut(), font_color);
+        self
+    }
+
+    /// Font used for text.
+    fn font_name(&mut self, font_name: String) -> &mut Self {
+        Attributes::font_name(self.get_attributes_mut(), font_name);
+        self
+    }
+
+    /// Font size, in points, used for text.
+    /// default: 14.0, minimum: 1.0
+    fn font_size(&mut self, font_size: f32) -> &mut Self {
+        Attributes::font_size(self.get_attributes_mut(), font_size);
+        self
+    }
+
+    /// If a gradient fill is being used, this determines the angle of the fill.
+    fn gradient_angle(&mut self, gradient_angle: u32) -> &mut Self {
+        Attributes::gradient_angle(self.get_attributes_mut(), gradient_angle);
+        self
+    }
+
+    /// If the end points of an edge belong to the same group, i.e., have the same group attribute,
+    /// parameters are set to avoid crossings and keep the edges straight.
+    fn group(&mut self, group: String) -> &mut Self {
+        self.add_attribute("group", AttributeText::attr(group))
+    }
+
+    // TODO: constrain
+    /// Height of node, in inches.
+    /// default: 0.5, minimum: 0.02
+    fn height(&mut self, height: f32) -> &mut Self {
+        self.add_attribute("height", AttributeText::from(height))
+    }
+
+    /// Gives the name of a file containing an image to be displayed inside a node.
+    /// The image file must be in one of the recognized formats,
+    /// typically JPEG, PNG, GIF, BMP, SVG, or Postscript, and be able to be converted
+    /// into the desired output format.
+    fn image(&mut self, image: String) -> &mut Self {
+        self.add_attribute("image", AttributeText::quoted(image))
+    }
+
+    /// Controls how an image is positioned within its containing node.
+    /// Only has an effect when the image is smaller than the containing node.
+    fn image_pos(&mut self, image_pos: ImagePosition) -> &mut Self {
+        self.add_attribute("imagepos", AttributeText::from(image_pos))
+    }
+
+    /// Controls how an image fills its containing node.
+    fn image_scale_bool(&mut self, image_scale: bool) -> &mut Self {
+        self.add_attribute("imagescale", AttributeText::from(image_scale))
+    }
+
+    /// Controls how an image fills its containing node.
+    fn image_scale(&mut self, image_scale: ImageScale) -> &mut Self {
+        self.add_attribute("imagescale", AttributeText::from(image_scale))
+    }
+
+    /// Text label attached to objects.
+    fn label<S: Into<Cow<'a, str>>>(&mut self, text: S) -> &mut Self {
+        self.add_attribute("label", AttributeText::quoted(text))
+    }
+
+    // Vertical placement of labels for nodes, root graphs and clusters.
+    // For graphs and clusters, only labelloc=t and labelloc=b are allowed, corresponding to placement at the top and bottom, respectively.
+    // By default, root graph labels go on the bottom and cluster labels go on the top.
+    // Note that a subgraph inherits attributes from its parent. Thus, if the root graph sets labelloc=b, the subgraph inherits this value.
+    // For nodes, this attribute is used only when the height of the node is larger than the height of its label.
+    // If labelloc=t, labelloc=c, labelloc=b, the label is aligned with the top, centered, or aligned with the bottom of the node, respectively.
+    // By default, the label is vertically centered.
+    fn label_location(&mut self, label_location: LabelLocation) -> &mut Self {
+        Attributes::label_location(self.get_attributes_mut(), label_location);
+        self
+    }
+
+    /// Specifies layers in which the node, edge or cluster is present.
+    fn layer(&mut self, layer: String) -> &mut Self {
+        Attributes::layer(self.get_attributes_mut(), layer);
+        self
+    }
+
+    /// Sets x and y margins of canvas, in inches.
+    /// Both margins are set equal to the given value.
+    /// See [`crate::NodeAttributes::margin_point`]
+    fn margin(&mut self, margin: f32) -> &mut Self {
+        self.margin_point(Point::new_2d(margin, margin))
+    }
+
+    /// Sets x and y margins of canvas, in inches.
+    /// Specifies space left around the node’s label.
+    /// Note that the margin is not part of the drawing but just empty space left around the drawing.
+    /// The margin basically corresponds to a translation of drawing, as would be necessary to
+    /// center a drawing on a page.
+    /// Nothing is actually drawn in the margin.
+    /// To actually extend the background of a drawing, see the pad attribute.
+    /// Whilst it is possible to create a Point value with either a third co-ordinate
+    /// or a forced position, these are ignored for printing.
+    /// By default, the value is 0.11,0.055.
+    fn margin_point(&mut self, margin: Point) -> &mut Self {
+        Attributes::margin(self.get_attributes_mut(), margin);
+        self
+    }
+
+    /// By default, the justification of multi-line labels is done within the largest context that makes sense.
+    /// Thus, in the label of a polygonal node, a left-justified line will align with the left side of the node (shifted by the prescribed margin).
+    /// In record nodes, left-justified line will line up with the left side of the enclosing column of fields.
+    /// If nojustify=true, multi-line labels will be justified in the context of itself.
+    /// For example, if nojustify is set, the first label line is long, and the second is shorter and left-justified,
+    /// the second will align with the left-most character in the first line, regardless of how large the node might be.
+    fn no_justify(&mut self, no_justify: bool) -> &mut Self {
+        Attributes::no_justify(self.get_attributes_mut(), no_justify);
+        self
+    }
+
+    /// If ordering="out", then the outedges of a node, that is, edges with the node as its tail
+    /// node, must appear left-to-right in the same order in which they are defined in the input.
+    ///
+    /// If ordering="in", then the inedges of a node must appear left-to-right in the same order in
+    /// which they are defined in the input.
+    ///
+    /// If defined as a graph or subgraph attribute, the value is applied to all nodes in the graph
+    /// or subgraph.
+    ///
+    /// Note that the graph attribute takes precedence over the node attribute.
+    fn ordering(&mut self, ordering: Ordering) -> &mut Self {
+        Attributes::ordering(self.get_attributes_mut(), ordering);
+        self
+    }
+
+    // TODO: constrain to 0 - 360. Docs say min is 360 which should be max right?
+    /// Angle, in degrees, to rotate polygon node shapes.
+    /// For any number of polygon sides, 0 degrees rotation results in a flat base.
+    /// Used only if rotate is not defined.
+    /// Default: 0.0 and minimum: 360.0
+    fn orientation(&mut self, orientation: f32) -> &mut Self {
+        Attributes::orientation(self.get_attributes_mut(), orientation);
+        self
+    }
+
+    /// Specifies the width of the pen, in points, used to draw lines and curves,
+    /// including the boundaries of edges and clusters.
+    /// default: 1.0, minimum: 0.0
+    fn pen_width(&mut self, pen_width: f32) -> &mut Self {
+        Attributes::pen_width(self.get_attributes_mut(), pen_width);
+        self
+    }
+
+    /// Set number of peripheries used in polygonal shapes and cluster boundaries.
+    fn peripheries(&mut self, peripheries: u32) -> &mut Self {
+        self.add_attribute("penwidth", AttributeText::from(peripheries))
+    }
+
+    /// Position of node, or spline control points.
+    /// the position indicates the center of the node. On output, the coordinates are in points.
+    fn pos(&mut self, pos: Point) -> &mut Self {
+        Attributes::pos(self.get_attributes_mut(), pos);
+        self
+    }
+
+    // TODO: add post_spline
+
+    /// Rectangles for fields of records, in points.
+    fn rects(&mut self, rect: Rectangle) -> &mut Self {
+        self.add_attribute("rects", AttributeText::from(rect))
+    }
+
+    /// If true, force polygon to be regular, i.e., the vertices of the polygon will
+    /// lie on a circle whose center is the center of the node.
+    fn regular(&mut self, regular: bool) -> &mut Self {
+        self.add_attribute("regular", AttributeText::from(regular))
+    }
+
+    /// Gives the number of points used for a circle/ellipse node.
+    fn sample_points(&mut self, sample_points: u32) -> &mut Self {
+        self.add_attribute("samplepoints", AttributeText::from(sample_points))
+    }
+
+    /// Sets the shape of a node.
+    fn shape(&mut self, shape: Shape) -> &mut Self {
+        self.add_attribute("shape", AttributeText::from(shape))
+    }
+
+    // TODO: constrain
+    /// Print guide boxes in PostScript at the beginning of routesplines if showboxes=1, or at the end if showboxes=2.
+    /// (Debugging, TB mode only!)
+    /// default: 0, minimum: 0
+    fn show_boxes(&mut self, show_boxes: u32) -> &mut Self {
+        Attributes::show_boxes(self.get_attributes_mut(), show_boxes);
+        self
+    }
+
+    /// Number of sides when shape=polygon.
+    fn sides(&mut self, sides: u32) -> &mut Self {
+        self.add_attribute("sides", AttributeText::from(sides))
+    }
+
+    // TODO: constrain
+    /// Skew factor for shape=polygon.
+    /// Positive values skew top of polygon to right; negative to left.
+    /// default: 0.0, minimum: -100.0
+    fn skew(&mut self, skew: f32) -> &mut Self {
+        self.add_attribute("skew", AttributeText::from(skew))
+    }
+
+    /// If packmode indicates an array packing, sortv specifies an insertion order
+    /// among the components, with smaller values inserted first.
+    /// default: 0, minimum: 0
+    fn sortv(&mut self, sortv: u32) -> &mut Self {
+        Attributes::sortv(self.get_attributes_mut(), sortv);
+        self
+    }
+
+    /// Set style information for components of the graph.
+    fn style(&mut self, style: NodeStyle) -> &mut Self {
+        Attributes::style(self.get_attributes_mut(), Styles::Node(style));
+        self
+    }
+
+    /// If the object has a URL, this attribute determines which window of the browser is used for the URL.
+    fn target(&mut self, target: String) -> &mut Self {
+        Attributes::target(self.get_attributes_mut(), target);
+        self
+    }
+
+    /// Tooltip annotation attached to the node or edge.
+    /// If unset, Graphviz will use the object’s label if defined.
+    /// Note that if the label is a record specification or an HTML-like label,
+    /// the resulting tooltip may be unhelpful.
+    /// In this case, if tooltips will be generated, the user should set a tooltip attribute explicitly.
+    fn tooltip(&mut self, tooltip: String) -> &mut Self {
+        Attributes::tooltip(self.get_attributes_mut(), tooltip);
+        self
+    }
+
+    /// Hyperlinks incorporated into device-dependent output.
+    fn url(&mut self, url: String) -> &mut Self {
+        Attributes::url(self.get_attributes_mut(), url);
+        self
+    }
+
+    /// Sets the coordinates of the vertices of the node’s polygon, in inches.
+    /// A list of points, separated by spaces.
+    fn vertices(&mut self, vertices: String) -> &mut Self {
+        self.add_attribute("vertices", AttributeText::quoted(vertices))
+    }
+
+    /// Width of node, in inches.
+    /// This is taken as the initial, minimum width of the node.
+    /// If fixedsize is true, this will be the final width of the node.
+    /// Otherwise, if the node label requires more width to fit, the node’s
+    /// width will be increased to contain the label.
+    fn width(&mut self, width: f32) -> &mut Self {
+        self.add_attribute("width", AttributeText::from(width))
+    }
+
+    /// External label for a node or edge.
+    /// The label will be placed outside of the node but near it.
+    /// These labels are added after all nodes and edges have been placed.
+    /// The labels will be placed so that they do not overlap any node or label.
+    /// This means it may not be possible to place all of them.
+    /// To force placing all of them, set forcelabels=true.
+    fn xlabel(&mut self, xlabel: String) -> &mut Self {
+        Attributes::xlabel(self.get_attributes_mut(), xlabel);
+        self
+    }
+
+    /// Position of an exterior label, in points.
+    /// The position indicates the center of the label.
+    fn xlp(&mut self, xlp: Point) -> &mut Self {
+        Attributes::xlp(self.get_attributes_mut(), xlp);
+        self
+    }
+
+    /// Add an attribute to the node.
+    fn add_attribute<S: Into<String>>(
+        &mut self,
+        key: S,
+        value: AttributeText<'a>,
+    ) -> &mut Self;
+
+    /// Add multiple attribures to the node.
+    fn add_attributes(
+        &'a mut self,
+        attributes: HashMap<String, AttributeText<'a>>,
+    ) -> &mut Self;
+
+    fn get_attributes_mut(&mut self) -> &mut IndexMap<String, AttributeText<'a>>;
+}
+
+pub trait EdgeAttributes<'a> {
+    /// Style of arrowhead on the head node of an edge.
+    /// This will only appear if the dir attribute is forward or both.
+    fn arrow_head(&mut self, arrowhead: ArrowType) -> &mut Self {
+        self.add_attribute("arrowhead", AttributeText::from(arrowhead))
+    }
+
+    // TODO: constrain
+    /// Multiplicative scale factor for arrowheads.
+    /// default: 1.0, minimum: 0.0
+    fn arrow_size(&mut self, arrow_size: f32) -> &mut Self {
+        self.add_attribute("arrowsize", AttributeText::from(arrow_size))
+    }
+
+    /// Style of arrowhead on the tail node of an edge.
+    /// This will only appear if the dir attribute is back or both.
+    fn arrowtail(&mut self, arrowtail: ArrowType) -> &mut Self {
+        self.add_attribute("arrowtail", AttributeText::from(arrowtail))
+    }
+
+    /// Classnames to attach to the edge’s SVG element.
+    /// Combine with stylesheet for styling SVG output using CSS classnames.
+    /// Multiple space-separated classes are supported.
+    fn class(&mut self, class: String) -> &mut Self {
+        Attributes::class(self.get_attributes_mut(), class);
+        self
+    }
+
+    /// Basic drawing color for graphics, not text. For the latter, use the fontcolor attribute.
+    /// If any fraction is used, the colors are drawn in series, with each color being given
+    /// roughly its specified fraction of the edge.
+    fn color(&mut self, color: Color<'a>) -> &mut Self {
+        Attributes::color(self.get_attributes_mut(), color);
+        self
+    }
+
+    /// Basic drawing color for graphics, not text. For the latter, use the fontcolor attribute.
+    /// if colorList has no fractions, the edge is drawn using parallel splines or lines,
+    /// one for each color in the list, in the order given.
+    /// The head arrow, if any, is drawn using the first color in the list, and the tail
+    /// arrow, if any, the second color. This supports the common case of drawing opposing edges,
+    /// but using parallel splines instead of separately routed multiedges.
+    /// If any fraction is used, the colors are drawn in series, with each color being given
+    /// roughly its specified fraction of the edge.
+    fn color_with_colorlist(&mut self, color: ColorList<'a>) -> &mut Self {
+        Attributes::color_with_colorlist(self.get_attributes_mut(), color);
+        self
+    }
+
+    /// This attribute specifies a color scheme namespace: the context for interpreting color names.
+    /// In particular, if a color value has form "xxx" or "//xxx", then the color xxx will be evaluated
+    /// according to the current color scheme. If no color scheme is set, the standard X11 naming is used.
+    /// For example, if colorscheme=bugn9, then color=7 is interpreted as color="/bugn9/7".
+    fn color_scheme(&mut self, color_scheme: String) -> &mut Self {
+        Attributes::color_scheme(self.get_attributes_mut(), color_scheme);
+        self
+    }
+
+    /// Comments are inserted into output. Device-dependent
+    fn comment(&mut self, comment: String) -> &mut Self {
+        self.add_attribute("comment", AttributeText::attr(comment));
+        self
+    }
+
+    /// If false, the edge is not used in ranking the nodes.
+    fn constraint(&mut self, constraint: bool) -> &mut Self {
+        self.add_attribute("constraint", AttributeText::from(constraint))
+    }
+
+    /// If true, attach edge label to edge by a 2-segment polyline, underlining the label,
+    /// then going to the closest point of spline.
+    fn decorate(&mut self, decorate: bool) -> &mut Self {
+        self.add_attribute("decorate", AttributeText::from(decorate))
+    }
+
+    /// Edge type for drawing arrowheads.
+    /// Indicates which ends of the edge should be decorated with an arrowhead.
+    /// The actual style of the arrowhead can be specified using the arrowhead and arrowtail attributes.
+    fn dir(&mut self, dir: Direction) -> &mut Self {
+        self.add_attribute("dir", AttributeText::from(dir))
+    }
+
+    /// If the edge has a URL or edgeURL attribute, edgetarget determines which window
+    /// of the browser is used for the URL attached to the non-label part of the edge.
+    /// Setting edgetarget=_graphviz will open a new window if it doesn’t already exist,
+    /// or reuse it if it does.
+    fn edge_target(&mut self, edge_target: String) -> &mut Self {
+        self.add_attribute("edgetarget", AttributeText::escaped(edge_target))
+    }
+
+    /// Tooltip annotation attached to the non-label part of an edge.
+    /// Used only if the edge has a URL or edgeURL attribute.
+    fn edge_tooltip(&mut self, edge_tooltip: String) -> &mut Self {
+        self.add_attribute("edgetooltip", AttributeText::escaped(edge_tooltip))
+    }
+
+    /// The link for the non-label parts of an edge.
+    /// edgeURL overrides any URL defined for the edge.
+    /// Also, edgeURL is used near the head or tail node unless overridden by headURL or tailURL, respectively.
+    fn edge_url(&mut self, edge_url: String) -> &mut Self {
+        self.add_attribute("edgeurl", AttributeText::escaped(edge_url))
+    }
+
+    // TODO: color list
+    /// Color used to fill the background of a node or cluster assuming style=filled, or a filled arrowhead.
+    fn fill_color(&mut self, fill_color: Color<'a>) -> &mut Self {
+        Attributes::fill_color(self.get_attributes_mut(), fill_color);
+        self
+    }
+
+    // TODO: color list
+    /// Color used for text.
+    fn font_color(&mut self, font_color: Color<'a>) -> &mut Self {
+        Attributes::font_color(self.get_attributes_mut(), font_color);
+        self
+    }
+
+    /// Font used for text.
+    fn font_name(&mut self, font_name: String) -> &mut Self {
+        Attributes::font_name(self.get_attributes_mut(), font_name);
+        self
+    }
+
+    /// Font size, in points, used for text.
+    /// default: 14.0, minimum: 1.0
+    fn font_size(&mut self, font_size: f32) -> &mut Self {
+        Attributes::font_size(self.get_attributes_mut(), font_size);
+        self
+    }
+
+    /// Position of an edge’s head label, in points. The position indicates the center of the label.
+    fn head_lp(&mut self, head_lp: Point) -> &mut Self {
+        self.add_attribute("head_lp", AttributeText::from(head_lp))
+    }
+
+    /// If true, the head of an edge is clipped to the boundary of the head node;
+    /// otherwise, the end of the edge goes to the center of the node, or the center
+    /// of a port, if applicable.
+    fn head_clip(&mut self, head_clip: bool) -> &mut Self {
+        self.add_attribute("headclip", AttributeText::from(head_clip))
+    }
+
+    /// Text label to be placed near head of edge.
+    fn head_label(&mut self, head_label: String) -> &mut Self {
+        self.add_attribute("headlabel", AttributeText::quoted(head_label))
+    }
+
+    /// Indicates where on the head node to attach the head of the edge.
+    /// In the default case, the edge is aimed towards the center of the node,
+    /// and then clipped at the node boundary.
+    fn head_port(&mut self, head_port: PortPosition) -> &mut Self {
+        self.add_attribute("headport", AttributeText::from(head_port))
+    }
+
+    /// If the edge has a headURL, headtarget determines which window of the browser is used for the URL.
+    /// Setting headURL=_graphviz will open a new window if the window doesn’t already exist,
+    /// or reuse the window if it does.
+    /// If undefined, the value of the target is used.
+    fn head_target(&mut self, head_target: String) -> &mut Self {
+        self.add_attribute("headtarget", AttributeText::escaped(head_target))
+    }
+
+    /// Tooltip annotation attached to the head of an edge.
+    /// Used only if the edge has a headURL attribute.
+    fn head_tooltip(&mut self, head_tooltip: String) -> &mut Self {
+        self.add_attribute("headtooltip", AttributeText::escaped(head_tooltip))
+    }
+
+    /// If defined, headURL is output as part of the head label of the edge.
+    /// Also, this value is used near the head node, overriding any URL value.
+    fn head_url(&mut self, head_url: String) -> &mut Self {
+        self.add_attribute("headURL", AttributeText::escaped(head_url))
+    }
+
+    /// An escString or an HTML label.
+    fn label(&mut self, label: String) -> &mut Self {
+        Attributes::label(self.get_attributes_mut(), label);
+        self
+    }
+
+    // TODO: constrain
+    /// Determines, along with labeldistance, where the headlabel / taillabel are
+    /// placed with respect to the head / tail in polar coordinates.
+    /// The origin in the coordinate system is the point where the edge touches the node.
+    /// The ray of 0 degrees goes from the origin back along the edge, parallel to the edge at the origin.
+    /// The angle, in degrees, specifies the rotation from the 0 degree ray,
+    /// with positive angles moving counterclockwise and negative angles moving clockwise.
+    /// default: -25.0, minimum: -180.0
+    fn label_angle(&mut self, label_angle: f32) -> &mut Self {
+        self.add_attribute("labelangle", AttributeText::from(label_angle))
+    }
+
+    /// Multiplicative scaling factor adjusting the distance that the headlabel / taillabel is from
+    /// the head / tail node.
+    /// default: 1.0, minimum: 0.0
+    fn label_distance(&mut self, label_distance: f32) -> &mut Self {
+        self.add_attribute("labeldistance", AttributeText::from(label_distance))
+    }
+
+    /// If true, allows edge labels to be less constrained in position.
+    /// In particular, it may appear on top of other edges.
+    fn label_float(&mut self, label_float: bool) -> &mut Self {
+        self.add_attribute("labelfloat", AttributeText::from(label_float))
+    }
+
+    /// Color used for headlabel and taillabel.
+    fn label_font_color(&mut self, label_font_color: Color<'a>) -> &mut Self {
+        self.add_attribute("labelfontcolor", AttributeText::from(label_font_color))
+    }
+
+    /// Font used for headlabel and taillabel.
+    /// If not set, defaults to edge’s fontname.
+    fn label_font_name(&mut self, label_font_name: String) -> &mut Self {
+        self.add_attribute("labelfontname", AttributeText::attr(label_font_name))
+    }
+
+    // TODO: constrains
+    /// Font size, in points, used for headlabel and taillabel.
+    /// If not set, defaults to edge’s fontsize.
+    /// default: 14.0, minimum: 1.0
+    fn label_font_size(&mut self, label_font_size: f32) -> &mut Self {
+        self.add_attribute("labelfontsize", AttributeText::from(label_font_size))
+    }
+
+    /// If the edge has a URL or labelURL attribute, this attribute determines
+    ///  which window of the browser is used for the URL attached to the label.
+    fn label_target(&mut self, label_target: String) -> &mut Self {
+        self.add_attribute("labeltarget", AttributeText::escaped(label_target))
+    }
+
+    /// Tooltip annotation attached to label of an edge.
+    /// Used only if the edge has a URL or labelURL attribute.
+    fn label_tooltip(&mut self, label_tooltip: String) -> &mut Self {
+        self.add_attribute("labeltooltip", AttributeText::escaped(label_tooltip))
+    }
+
+    /// If defined, labelURL is the link used for the label of an edge.
+    /// labelURL overrides any URL defined for the edge.
+    fn label_url(&mut self, label_url: String) -> &mut Self {
+        self.add_attribute("labelurl", AttributeText::escaped(label_url))
+    }
+
+    fn layer(&mut self, layer: String) -> &mut Self {
+        Attributes::layer(self.get_attributes_mut(), layer);
+        self
+    }
+
+    fn lhead(&mut self, lhead: String) -> &mut Self {
+        self.add_attribute("lhead", AttributeText::quoted(lhead))
+    }
+
+    /// Label position
+    /// The position indicates the center of the label.
+    fn label_position(&mut self, lp: Point) -> &mut Self {
+        Attributes::label_position(self.get_attributes_mut(), lp);
+        self
+    }
+
+    /// Logical tail of an edge.
+    /// When compound=true, if ltail is defined and is the name of a cluster
+    /// containing the real tail, the edge is clipped to the boundary of the cluster.
+    fn ltail(&mut self, ltail: String) -> &mut Self {
+        self.add_attribute("ltail", AttributeText::quoted(ltail))
+    }
+
+    /// Minimum edge length (rank difference between head and tail).
+    fn min_len(&mut self, min_len: u32) -> &mut Self {
+        self.add_attribute("minlen", AttributeText::from(min_len))
+    }
+
+    fn no_justify(&mut self, no_justify: bool) -> &mut Self {
+        self.add_attribute("nojustify", AttributeText::from(no_justify))
+    }
+
+    fn pen_width(&mut self, pen_width: f32) -> &mut Self {
+        Attributes::pen_width(self.get_attributes_mut(), pen_width);
+        self
+    }
+
+    /// Position of node, or spline control points.
+    /// the position indicates the center of the node. On output, the coordinates are in points.
+    fn pos(&mut self, pos: Point) -> &mut Self {
+        Attributes::pos(self.get_attributes_mut(), pos);
+        self
+    }
+
+    /// Edges with the same head and the same samehead value are aimed at the same point on the head.
+    fn same_head(&mut self, same_head: String) -> &mut Self {
+        self.add_attribute("samehead", AttributeText::quoted(same_head))
+    }
+
+    /// Edges with the same tail and the same sametail value are aimed at the same point on the tail.
+    fn same_tail(&mut self, same_tail: String) -> &mut Self {
+        self.add_attribute("sametail", AttributeText::quoted(same_tail))
+    }
+
+    // TODO: constrain
+    /// Print guide boxes in PostScript at the beginning of routesplines if showboxes=1, or at the
+    /// end if showboxes=2.
+    /// (Debugging, TB mode only!)
+    /// default: 0, minimum: 0
+    fn show_boxes(&mut self, show_boxes: u32) -> &mut Self {
+        Attributes::show_boxes(self.get_attributes_mut(), show_boxes);
+        self
+    }
+
+    /// Set style information for components of the graph.
+    fn style(&mut self, style: EdgeStyle) -> &mut Self {
+        Attributes::style(self.get_attributes_mut(), Styles::Edge(style));
+        self
+    }
+
+    /// Position of an edge’s tail label, in points.
+    /// The position indicates the center of the label.
+    fn tail_lp(&mut self, tail_lp: Point) -> &mut Self {
+        self.add_attribute("tail_lp", AttributeText::from(tail_lp))
+    }
+
+    /// If true, the tail of an edge is clipped to the boundary of the tail node; otherwise,
+    /// the end of the edge goes to the center of the node, or the center of a port, if applicable.
+    fn tail_clip(&mut self, tail_clip: bool) -> &mut Self {
+        self.add_attribute("tailclip", AttributeText::from(tail_clip))
+    }
+
+    /// Text label to be placed near tail of edge.
+    fn tail_label(&mut self, tail_label: String) -> &mut Self {
+        self.add_attribute("taillabel", AttributeText::quoted(tail_label))
+    }
+
+    /// Indicates where on the tail node to attach the tail of the edge.
+    fn tail_port(&mut self, tail_port: PortPosition) -> &mut Self {
+        self.add_attribute("tailport", AttributeText::from(tail_port))
+    }
+
+    /// If the edge has a tailURL, tailtarget determines which window of the browser is used for the URL.
+    fn tail_target(&mut self, tail_target: String) -> &mut Self {
+        self.add_attribute("tailtarget", AttributeText::escaped(tail_target))
+    }
+
+    /// Tooltip annotation attached to the tail of an edge.
+    fn tail_tooltip(&mut self, tail_tooltip: String) -> &mut Self {
+        self.add_attribute("tailtooltip", AttributeText::escaped(tail_tooltip))
+    }
+
+    /// If defined, tailURL is output as part of the tail label of the edge.
+    /// Also, this value is used near the tail node, overriding any URL value.
+    fn tail_url(&mut self, tail_url: String) -> &mut Self {
+        self.add_attribute("tailURL", AttributeText::escaped(tail_url))
+    }
+
+    /// If the object has a URL, this attribute determines which window of the browser is used for the URL.
+    fn target(&mut self, target: String) -> &mut Self {
+        self.add_attribute("target", AttributeText::escaped(target))
+    }
+
+    /// Tooltip annotation attached to the node or edge.
+    /// If unset, Graphviz will use the object’s label if defined.
+    /// Note that if the label is a record specification or an HTML-like label,
+    /// the resulting tooltip may be unhelpful.
+    /// In this case, if tooltips will be generated, the user should set a tooltip attribute explicitly.
+    fn tooltip(&mut self, tooltip: String) -> &mut Self {
+        Attributes::tooltip(self.get_attributes_mut(), tooltip);
+        self
+    }
+
+    /// Hyperlinks incorporated into device-dependent output.
+    fn url(&mut self, url: String) -> &mut Self {
+        Attributes::url(self.get_attributes_mut(), url);
+        self
+    }
+
+    // TODO: contrain
+    /// Weight of edge.
+    /// The heavier the weight, the shorter, straighter and more vertical the edge is.
+    /// default: 1, minimum: 0
+    fn weight(&mut self, weight: u32) -> &mut Self {
+        self.add_attribute("weight", AttributeText::attr(weight.to_string()))
+    }
+
+    /// External label for a node or edge.
+    /// The label will be placed outside of the node but near it.
+    /// These labels are added after all nodes and edges have been placed.
+    /// The labels will be placed so that they do not overlap any node or label.
+    /// This means it may not be possible to place all of them.
+    /// To force placing all of them, set forcelabels=true.
+    fn xlabel(&mut self, xlabel: String) -> &mut Self {
+        Attributes::xlabel(self.get_attributes_mut(), xlabel);
+        self
+    }
+
+    /// Position of an exterior label, in points.
+    /// The position indicates the center of the label.
+    fn xlp(&mut self, xlp: Point) -> &mut Self {
+        Attributes::xlp(self.get_attributes_mut(), xlp);
+        self
+    }
+
+    fn add_attribute<S: Into<String>>(
+        &mut self,
+        key: S,
+        value: AttributeText<'a>,
+    ) -> &mut Self;
+
+    fn get_attributes_mut(&mut self) -> &mut IndexMap<String, AttributeText<'a>>;
+
+    // fn add_attribute<S: Into<String>>(
+    //     &self,
+    //     key: S,
+    //     value: AttributeText<'a>
+    // ) {
+    //     self.get_attributes().insert(key.into(), value);
+    // }
+
+    // fn get_attributes(&self) -> IndexMap<String, AttributeText<'a>>;
+
+    // fn get_attributes_mut(&self) -> &mut IndexMap<String, AttributeText<'a>>;
+
+    // fn to_dot_string(&self) -> String;
+}
+
+pub(crate) fn fmt_attributes(attributes: &IndexMap<String, AttributeText>) -> String {
+    let mut dot_string = String::from("");
+    if !attributes.is_empty() {
+        dot_string.push_str(" [");
+        let mut iter = attributes.iter();
+        let first = iter.next().unwrap();
+        dot_string.push_str(format!("{}={}", first.0, first.1.dot_string()).as_str());
+        for (key, value) in iter {
+            dot_string.push_str(", ");
+            dot_string.push_str(format!("{}={}", key, value.dot_string()).as_str());
+        }
+        dot_string.push_str("]");
+    }
+
+    dot_string
+}
+
 #[cfg(test)]
 mod test {
     use crate::attributes::{
diff --git a/src/attributes/shape.rs b/src/attributes/shape.rs
index be37ccc..3c7469e 100644
--- a/src/attributes/shape.rs
+++ b/src/attributes/shape.rs
@@ -91,9 +91,9 @@ impl<'a> DotString<'a> for Shape {
             Shape::Invtriangle => "invtriangle".into(),
             Shape::Invtrapezium => "invtrapezium".into(),
             Shape::Invhouse => "invhouse".into(),
-            Shape::Mdiamond => "mdiamond".into(),
-            Shape::Msquare => "msquare".into(),
-            Shape::Mcircle => "mcircle".into(),
+            Shape::Mdiamond => "Mdiamond".into(),
+            Shape::Msquare => "Msquare".into(),
+            Shape::Mcircle => "Mcircle".into(),
             Shape::Record => "record".into(),
             Shape::Rect => "rect".into(),
             Shape::Rectangle => "rectangle".into(),