use latex to get string bounder (#1914)

* tikz: use latex to get string bounder

use !pragma to configure tex and preamble, and the default is like this:

```
!pragma TexSystem xelatex
```

and the template is
```
\documentclass{standalone}
\usepackage{tikz}
\usepackage{aeguill}
% preamble
\begin{document}
```
latex implementations is inspired by matplotlib

* tikz: latex show log if fail

* tikz: add custom preamble to tex

```
!pragma TexPreamble \usepackage{ctex}
```

src/net/atmp/ImageBuilder.java

@@ -333,9 +333,9 @@ private UGraphic createUGraphic(final XDimension2D dim, double scaleFactor, Prag
 		case VDX:
 			return new UGraphicVdx(backcolor, colorMapper, stringBounder);
 		case LATEX:
-			return new UGraphicTikz(backcolor, colorMapper, stringBounder, scaleFactor, true);
+			return new UGraphicTikz(backcolor, colorMapper, stringBounder, scaleFactor, true, pragma);
 		case LATEX_NO_PREAMBLE:
-			return new UGraphicTikz(backcolor, colorMapper, stringBounder, scaleFactor, false);
+			return new UGraphicTikz(backcolor, colorMapper, stringBounder, scaleFactor, false, pragma);
 		case BRAILLE_PNG:
 			return new UGraphicBraille(backcolor, colorMapper, stringBounder);
 		case UTXT:

src/net/sourceforge/plantuml/FileFormat.java

@@ -224,25 +224,47 @@ public boolean matchesProperty(String propertyName) {
 
 	private StringBounder getTikzStringBounder(final TikzFontDistortion tikzFontDistortion) {
 		return new StringBounderRaw(FileFormat.gg.getFontRenderContext()) {
+
+			private final LatexManager latexManager = new LatexManager(tikzFontDistortion.getTexSystem(), tikzFontDistortion.getTexPreamble());
+
 			public String toString() {
 				return "FileFormat::getTikzStringBounder";
 			}
 
 			protected XDimension2D calculateDimensionInternal(UFont font, String text) {
-				text = text.replace("\t", "    ");
-				final XDimension2D w1 = getJavaDimension(font.goTikz(-1), text);
-				final XDimension2D w2 = getJavaDimension(font.goTikz(0), text);
-				final XDimension2D w3 = getJavaDimension(font.goTikz(1), text);
-				final double factor = (w3.getWidth() - w1.getWidth()) / w2.getWidth();
-				final double distortion = tikzFontDistortion.getDistortion();
-				final double magnify = tikzFontDistortion.getMagnify();
-				final double delta = (w2.getWidth() - w1.getWidth()) * factor * distortion;
-				return w2.withWidth(Math.max(w1.getWidth(), magnify * w2.getWidth() - delta));
+				double[] widthHeightDepth = latexManager.getWidthHeightDepth(styleText(font, text));
+				return new XDimension2D(widthHeightDepth[0], widthHeightDepth[1] + widthHeightDepth[2]);
 			}
 
 			public boolean matchesProperty(String propertyName) {
 				return false;
 			}
+
+			public double getDescent(UFont font, String text) {
+				double[] widthHeightDepth = latexManager.getWidthHeightDepth(styleText(font, text));
+				return widthHeightDepth[2];
+			}
+
+			protected String styleText(UFont font, String text) {
+				StringBuilder sb = new StringBuilder();
+				final boolean italic = font.isItalic();
+				final boolean bold = font.isBold();
+
+				if (italic)
+					sb.append("\\textit{");
+
+				if (bold)
+					sb.append("\\textbf{");
+
+				sb.append(text);
+				if (bold)
+					sb.append("}");
+
+				if (italic)
+					sb.append("}");
+
+				return sb.toString();
+			}
 		};
 	}
 

src/net/sourceforge/plantuml/LatexManager.java

@@ -0,0 +1,98 @@
+package net.sourceforge.plantuml;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.io.PrintWriter;
+import java.nio.file.Files;
+
+public class LatexManager implements AutoCloseable {
+
+	private final Process process;
+	private final PrintWriter writer;
+	private final BufferedReader reader;
+
+	private static final String TEMPLATE_PREFIX = "{" +
+					"\\catcode`\\^=\\active" +
+					"\\catcode`\\%=\\active" +
+					"\\sbox0{{" +
+					"\\catcode`\\^=\\active\\def^{\\ifmmode\\sp\\else\\^{}\\fi}" +
+					"\\catcode`\\%=\\active\\def%{\\%}";
+	private static final String TEMPLATE_SUFFIX = "}}" +
+					"\\typeout{\\the\\wd0,\\the\\ht0,\\the\\dp0}" +
+					"}";
+
+	public LatexManager(String system, String preamble) {
+		String command = (system != null && !system.isEmpty()) ? system : "xelatex";
+		if (!command.endsWith("latex")) {
+			throw new IllegalArgumentException("command " + command + " is unsupported");
+		}
+		try {
+			File tempDir = Files.createTempDirectory("plantuml-latex-").toFile();
+			tempDir.deleteOnExit();
+			this.process = new ProcessBuilder(command, "-halt-on-error")
+							.directory(tempDir)
+							.start();
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+		this.writer = new PrintWriter(new OutputStreamWriter(this.process.getOutputStream()), true);
+		this.reader = new BufferedReader(new InputStreamReader(this.process.getInputStream()));
+		this.writer.println("\\documentclass{standalone}\n" +
+						"\\usepackage{tikz}\n" +
+						"\\usepackage{aeguill}\n" +
+						((preamble != null && !preamble.isEmpty()) ? preamble + "\n" : "") +
+						"\\begin{document}\n" +
+						"\\typeout{latex_query_start}");
+		if (expect("*latex_query_start") == null) {
+			throw new IllegalArgumentException("please install " + command + ", and package `tikz`, `aeguill` (and `ae`)");
+		}
+	}
+
+	private String expect(String s) {
+		StringBuilder sb = new StringBuilder();
+		while (true) {
+			String line;
+			try {
+				line = this.reader.readLine();
+			} catch (IOException e) {
+				throw new RuntimeException(e);
+			}
+			if (line == null) {
+				break;
+			}
+			if (line.startsWith("*Missing character")) {
+				System.err.println(line);
+				break;
+			}
+			sb.append(line);
+			sb.append(System.lineSeparator());
+			if (line.startsWith(s)) {
+				return sb.toString();
+			}
+		}
+		System.err.println(sb);
+		return null;
+	}
+
+	public double[] getWidthHeightDepth(String s) {
+		this.writer.println(TEMPLATE_PREFIX + s + TEMPLATE_SUFFIX);
+		String output = this.expect("*");
+		if (output == null) {
+			throw new IllegalArgumentException("cannot get width, height, depth, text: " + s);
+		}
+		String[] pts = output.trim().replace("*", "").split(",", 3);
+		double width = Double.parseDouble(pts[0].replace("pt", ""));
+		double height = Double.parseDouble(pts[1].replace("pt", ""));
+		double depth = Double.parseDouble(pts[2].replace("pt", ""));
+		return new double[] {width, height, depth};
+	}
+
+	@Override
+	public void close() {
+		this.process.destroy();
+	}
+
+}

src/net/sourceforge/plantuml/TikzFontDistortion.java

@@ -37,11 +37,15 @@
 
 import java.util.StringTokenizer;
 
+import net.sourceforge.plantuml.skin.Pragma;
+
 public class TikzFontDistortion {
 	// ::remove file when __HAXE__
 
 	private final double magnify;
 	private final double distortion;
+	private String texSystem;
+	private String texPreamble;
 
 	private TikzFontDistortion(double magnify, double distortion) {
 		this.magnify = magnify;
@@ -84,4 +88,17 @@ public final double getDistortion() {
 		return distortion;
 	}
 
+	public String getTexSystem() {
+		return texSystem;
+	}
+
+	public String getTexPreamble() {
+		return texPreamble;
+	}
+
+	public void updateFromPragma(Pragma pragma) {
+		this.texSystem = pragma.getValue("texsystem");
+		this.texPreamble = pragma.getValue("texpreamble");
+	}
+
 }

src/net/sourceforge/plantuml/UmlDiagram.java

@@ -128,6 +128,7 @@ final protected ImageData exportDiagramNow(OutputStream os, int index, FileForma
 			throws IOException {
 
 		fileFormatOption = fileFormatOption.withTikzFontDistortion(getSkinParam().getTikzFontDistortion());
+		fileFormatOption.getTikzFontDistortion().updateFromPragma(getPragma());
 
 		// ::comment when __CORE__
 		if (fileFormatOption.getFileFormat() == FileFormat.PDF)

src/net/sourceforge/plantuml/klimt/drawing/tikz/UGraphicTikz.java

@@ -54,15 +54,16 @@
 import net.sourceforge.plantuml.klimt.shape.UPolygon;
 import net.sourceforge.plantuml.klimt.shape.URectangle;
 import net.sourceforge.plantuml.klimt.shape.UText;
+import net.sourceforge.plantuml.skin.Pragma;
 import net.sourceforge.plantuml.tikz.TikzGraphics;
 import net.sourceforge.plantuml.url.Url;
 
 public class UGraphicTikz extends AbstractUGraphic<TikzGraphics> implements ClipContainer {
 
 	public UGraphicTikz(HColor defaultBackground, ColorMapper colorMapper, StringBounder stringBounder, double scale,
-			boolean withPreamble) {
+			boolean withPreamble, Pragma pragma) {
 		super(stringBounder);
-		copy(defaultBackground, colorMapper, new TikzGraphics(scale, withPreamble, colorMapper));
+		copy(defaultBackground, colorMapper, new TikzGraphics(scale, withPreamble, colorMapper, pragma));
 		register();
 	}
 

src/net/sourceforge/plantuml/sudoku/GraphicsSudoku.java

@@ -89,7 +89,7 @@ public ImageData writeImageEps(OutputStream os) throws IOException {
 
 	public ImageData writeImageLatex(OutputStream os, FileFormat fileFormat) throws IOException {
 		final UGraphicTikz ug = new UGraphicTikz(HColors.WHITE, ColorMapper.IDENTITY,
-				FileFormat.LATEX.getDefaultStringBounder(), 1, fileFormat == FileFormat.LATEX);
+				FileFormat.LATEX.getDefaultStringBounder(), 1, fileFormat == FileFormat.LATEX, null);
 		drawInternal(ug);
 		ug.writeToStream(os, null, -1); // dpi param is not used
 		return ImageDataSimple.ok();

src/net/sourceforge/plantuml/tikz/TikzGraphics.java

@@ -56,6 +56,7 @@
 import net.sourceforge.plantuml.klimt.drawing.eps.EpsGraphics;
 import net.sourceforge.plantuml.klimt.geom.USegment;
 import net.sourceforge.plantuml.klimt.geom.USegmentType;
+import net.sourceforge.plantuml.skin.Pragma;
 import net.sourceforge.plantuml.url.Url;
 import net.sourceforge.plantuml.utils.Log;
 import net.sourceforge.plantuml.version.Version;
@@ -78,13 +79,15 @@ public class TikzGraphics {
 	private final double scale;
 	private String dash = null;
 	private final ColorMapper mapper;
+	private final String preamble;
 
 	private final Map<Color, String> colornames = new LinkedHashMap<Color, String>();
 
-	public TikzGraphics(double scale, boolean withPreamble, ColorMapper mapper) {
+	public TikzGraphics(double scale, boolean withPreamble, ColorMapper mapper, Pragma pragma) {
 		this.withPreamble = withPreamble;
 		this.scale = scale;
 		this.mapper = mapper;
+		this.preamble = pragma != null ? pragma.getValue("texpreamble") : null;
 	}
 
 	private final Map<String, Integer> styles = new LinkedHashMap<String, Integer>();
@@ -158,6 +161,9 @@ public void createData(OutputStream os) throws IOException {
 				out(os, "\\usetikzlibrary{calc}");
 				out(os, "\\usepackage{hyperref}");
 			}
+			if (preamble != null && !preamble.isEmpty()) {
+				out(os, preamble);
+			}
 			out(os, "\\begin{document}");
 		}
 		out(os, "% generated by Plantuml " + Version.versionString(15));
@@ -321,7 +327,7 @@ public void text(double x, double y, String text, boolean underline, boolean ita
 			sb.append(",color=");
 			sb.append(getColorName(color));
 		}
-		sb.append("]{");
+		sb.append(",inner sep=0]{");
 		if (pendingUrl == null || urlIgnoreText) {
 			if (underline)
 				sb.append("\\underline{");