Source code for toyplot.reportlab

# Copyright 2014, Sandia Corporation. Under the terms of Contract
# DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains certain
# rights in this software.

"""Support functions for rendering using ReportLab."""


import base64
import io
import re

import numpy
import reportlab.lib.colors
import reportlab.lib.utils

import toyplot.color
import toyplot.units


[docs]def render(svg, canvas): """Render the SVG representation of a toyplot canvas to a ReportLab canvas. Parameters ---------- svg: xml.etree.ElementTree.Element SVG representation of a :class:`toyplot.canvas.Canvas` returned by :func:`toyplot.svg.render()`. canvas: reportlab.pdfgen.canvas.Canvas ReportLab canvas that will be used to render the plot. """ def get_fill(root, style): if "fill" not in style: return None, None # pragma: no cover gradient_id = re.match("^url[(]#(.*)[)]$", style["fill"]) if gradient_id: gradient_id = gradient_id.group(1) gradient_xml = root.find(".//*[@id='%s']" % gradient_id) if gradient_xml.tag != "linearGradient": raise NotImplementedError("Only linear gradients are implemented.") # pragma: no cover if gradient_xml.get("gradientUnits") != "userSpaceOnUse": raise NotImplementedError("Only userSpaceOnUse gradients are implemented.") # pragma: no cover return None, gradient_xml color = toyplot.color.css(style["fill"]) if color is None: return None, None fill_opacity = float(style.get("fill-opacity", 1.0)) opacity = float(style.get("opacity", 1.0)) fill = toyplot.color.rgba( color["r"], color["g"], color["b"], color["a"] * fill_opacity * opacity, ) return fill, None def get_stroke(style): if "stroke" not in style: return None # pragma: no cover color = toyplot.color.css(style["stroke"]) if color is None: return None stroke_opacity = float(style.get("stroke-opacity", 1.0)) opacity = float(style.get("opacity", 1.0)) return toyplot.color.rgba( color["r"], color["g"], color["b"], color["a"] * stroke_opacity * opacity, ) def get_line_cap(style): if "stroke-linecap" not in style: return 0 elif style["stroke-linecap"] == "butt": return 0 elif style["stroke-linecap"] == "round": return 1 elif style["stroke-linecap"] == "square": return 2 def get_font_family(style): if "font-family" not in style: return None # pragma: no cover bold = True if style.get("font-weight", "") == "bold" else False italic = True if style.get("font-style", "") == "italic" else False for font_family in style["font-family"].split(","): font_family = font_family.lower() if font_family in get_font_family.substitutions: font_family = get_font_family.substitutions[font_family] return get_font_family.font_table[(font_family, bold, italic)] raise ValueError("Unknown font family: %s" % style["font-family"]) # pragma: no cover get_font_family.font_table = { ("courier", False, False): "Courier", ("courier", True, False): "Courier-Bold", ("courier", False, True): "Courier-Oblique", ("courier", True, True): "Courier-BoldOblique", ("helvetica", False, False): "Helvetica", ("helvetica", True, False): "Helvetica-Bold", ("helvetica", False, True): "Helvetica-Oblique", ("helvetica", True, True): "Helvetica-BoldOblique", ("times", False, False): "Times-Roman", ("times", True, False): "Times-Bold", ("times", False, True): "Times-Italic", ("times", True, True): "Times-BoldItalic", } get_font_family.substitutions = { "courier": "courier", "helvetica": "helvetica", "monospace": "courier", "sans-serif": "helvetica", "serif": "times", "times": "times", } def set_fill_color(canvas, color): canvas.setFillColorRGB(color["r"], color["g"], color["b"]) canvas.setFillAlpha(numpy.asscalar(color["a"])) def set_stroke_color(canvas, color): canvas.setStrokeColorRGB(color["r"], color["g"], color["b"]) canvas.setStrokeAlpha(numpy.asscalar(color["a"])) def render_element(root, element, canvas, styles): canvas.saveState() current_style = {} if styles: current_style.update(styles[-1]) for declaration in element.get("style", "").split(";"): if declaration == "": continue key, value = declaration.split(":") current_style[key] = value styles.append(current_style) if "stroke-width" in current_style: canvas.setLineWidth(float(current_style["stroke-width"])) if "stroke-dasharray" in current_style: canvas.setDash([float(length) for length in current_style["stroke-dasharray"].split(",")]) if current_style.get("visibility") != "hidden": if "transform" in element.attrib: for transformation in element.get("transform").split(")")[::1]: if transformation: transform, arguments = transformation.split("(") arguments = arguments.split(",") if transform.strip() == "translate": if len(arguments) == 2: canvas.translate(float(arguments[0]), float(arguments[1])) elif transform.strip() == "rotate": if len(arguments) == 1: canvas.rotate(float(arguments[0])) if len(arguments) == 3: canvas.translate(float(arguments[1]), float(arguments[2])) canvas.rotate(float(arguments[0])) canvas.translate(-float(arguments[1]), -float(arguments[2])) if element.tag == "svg": if "background-color" in current_style: set_fill_color(canvas, toyplot.color.css(current_style["background-color"])) canvas.rect( 0, 0, float(element.get("width")[:-2]), float(element.get("height")[:-2]), stroke=0, fill=1, ) if current_style["border-style"] != "none": set_stroke_color(canvas, toyplot.color.css(current_style["border-color"])) canvas.setLineWidth(float(current_style["border-width"])) canvas.rect( 0, 0, float(element.get("width")[:-2]), float(element.get("height")[:-2]), stroke=1, fill=0, ) for child in element: render_element(root, child, canvas, styles) elif element.tag == "a": # At the moment, it doesn't look like reportlab supports external hyperlinks. for child in element: render_element(root, child, canvas, styles) elif element.tag == "g": if element.get("clip-path", None) is not None: clip_id = element.get("clip-path")[5:-1] clip_path = root.find(".//*[@id='%s']" % clip_id) for child in clip_path: if child.tag == "rect": x = float(child.get("x")) y = float(child.get("y")) width = float(child.get("width")) height = float(child.get("height")) path = canvas.beginPath() path.moveTo(x, y) path.lineTo(x + width, y) path.lineTo(x + width, y + height) path.lineTo(x, y + height) path.close() canvas.clipPath(path, stroke=0, fill=1) else: toyplot.log.error("Unhandled clip tag: %s", child.tag) # pragma: no cover for child in element: render_element(root, child, canvas, styles) elif element.tag == "clipPath": pass elif element.tag == "line": stroke = get_stroke(current_style) if stroke is not None: set_stroke_color(canvas, stroke) canvas.setLineCap(get_line_cap(current_style)) canvas.line( float(element.get("x1", 0)), float(element.get("y1", 0)), float(element.get("x2", 0)), float(element.get("y2", 0)), ) elif element.tag == "path": stroke = get_stroke(current_style) if stroke is not None: set_stroke_color(canvas, stroke) canvas.setLineCap(get_line_cap(current_style)) path = canvas.beginPath() commands = element.get("d").split() while commands: command = commands.pop(0) if command == "L": path.lineTo( float(commands.pop(0)), float(commands.pop(0))) elif command == "M": path.moveTo( float(commands.pop(0)), float(commands.pop(0))) canvas.drawPath(path) elif element.tag == "polygon": fill, fill_gradient = get_fill(root, current_style) if fill_gradient is not None: raise NotImplementedError("Gradient <polygon> not implemented.") # pragma: no cover if fill is not None: set_fill_color(canvas, fill) stroke = get_stroke(current_style) if stroke is not None: set_stroke_color(canvas, stroke) points = [point.split(",") for point in element.get("points").split()] path = canvas.beginPath() for point in points[:1]: path.moveTo(float(point[0]), float(point[1])) for point in points[1:]: path.lineTo(float(point[0]), float(point[1])) path.close() canvas.drawPath(path, stroke=stroke is not None, fill=fill is not None) elif element.tag == "rect": fill, fill_gradient = get_fill(root, current_style) if fill is not None: set_fill_color(canvas, fill) stroke = get_stroke(current_style) if stroke is not None: set_stroke_color(canvas, stroke) x = float(element.get("x", 0)) y = float(element.get("y", 0)) width = float(element.get("width")) height = float(element.get("height")) path = canvas.beginPath() path.moveTo(x, y) path.lineTo(x + width, y) path.lineTo(x + width, y + height) path.lineTo(x, y + height) path.close() if fill_gradient is not None: pdf_colors = [] pdf_offsets = [] for stop in fill_gradient: offset = float(stop.get("offset")) color = toyplot.color.css(stop.get("stop-color")) opacity = float(stop.get("stop-opacity")) pdf_colors.append(reportlab.lib.colors.Color(color["r"], color["g"], color["b"], color["a"] * opacity)) pdf_offsets.append(offset) canvas.saveState() canvas.clipPath(path, stroke=0, fill=1) canvas.setFillAlpha(1) canvas.linearGradient( float(fill_gradient.get("x1")), float(fill_gradient.get("y1")), float(fill_gradient.get("x2")), float(fill_gradient.get("y2")), pdf_colors, pdf_offsets, ) canvas.restoreState() canvas.drawPath(path, stroke=stroke is not None, fill=fill is not None) elif element.tag == "circle": fill, fill_gradient = get_fill(root, current_style) if fill_gradient is not None: raise NotImplementedError("Gradient <circle> not implemented.") # pragma: no cover if fill is not None: set_fill_color(canvas, fill) stroke = get_stroke(current_style) if stroke is not None: set_stroke_color(canvas, stroke) cx = float(element.get("cx", 0)) cy = float(element.get("cy", 0)) r = float(element.get("r")) canvas.circle(cx, cy, r, stroke=stroke is not None, fill=fill is not None) elif element.tag == "text": x = float(element.get("x", 0)) y = float(element.get("y", 0)) fill, fill_gradient = get_fill(element, current_style) stroke = get_stroke(current_style) font_family = get_font_family(current_style) font_size = toyplot.units.convert(current_style["font-size"], target="px") text = element.text canvas.saveState() canvas.setFont(font_family, font_size) if fill is not None: set_fill_color(canvas, fill) if stroke is not None: set_stroke_color(canvas, stroke) canvas.translate(x, y) canvas.scale(1, -1) canvas.drawString(0, 0, text) canvas.restoreState() elif element.tag == "image": import PIL.Image image = element.get("xlink:href") if not image.startswith("data:image/png;base64,"): raise ValueError("Unsupported image type.") # pragma: no cover image = base64.standard_b64decode(image[22:]) image = io.BytesIO(image) image = PIL.Image.open(image) image = reportlab.lib.utils.ImageReader(image) x = float(element.get("x", 0)) y = float(element.get("y", 0)) width = float(element.get("width")) height = float(element.get("height")) canvas.saveState() path = canvas.beginPath() set_fill_color(canvas, toyplot.color.rgb(1, 1, 1)) canvas.rect(x, y, width, height, stroke=0, fill=1) canvas.translate(x, y + height) canvas.scale(1, -1) canvas.drawImage(image=image, x=0, y=0, width=width, height=height, mask=None) canvas.restoreState() elif element.tag in ["defs", "title"]: pass else: raise Exception("unhandled tag: %s" % element.tag) # pragma: no cover styles.pop() canvas.restoreState() render_element(svg, svg, canvas, [])