extract overline, underline, and rule into their own files (#999)

src/buildCommon.js

@@ -9,6 +9,7 @@ import domTree from "./domTree";
 import fontMetrics from "./fontMetrics";
 import symbols from "./symbols";
 import utils from "./utils";
+import stretchy from "./stretchy";
 
 import type Options from "./Options";
 import type ParseNode from "./ParseNode";
@@ -274,6 +275,19 @@ const makeSpan = function(
     return span;
 };
 
+const makeLineSpan = function(
+    className: string,
+    options: Options,
+) {
+    // Fill the entire span instead of just a border. That way, the min-height
+    // value in katex.less will ensure that at least one screen pixel displays.
+    const line = stretchy.ruleSpan(className, options);
+    line.height = options.fontMetrics().defaultRuleThickness;
+    line.style.height = line.height + "em";
+    line.maxFontSize = 1.0;
+    return line;
+};
+
 /**
  * Makes an anchor with the given href, list of classes, list of children,
  * and options.
@@ -612,6 +626,7 @@ export default {
     makeSymbol,
     mathsym,
     makeSpan,
+    makeLineSpan,
     makeAnchor,
     makeFragment,
     makeVList,

src/buildHTML.js

@@ -474,63 +474,6 @@ groupTypes.spacing = function(group, options) {
     }
 };
 
-export const makeLineSpan = function(className, options, thickness) {
-    // Fill the entire span instead of just a border. That way, the min-height
-    // value in katex.less will ensure that at least one screen pixel displays.
-    const line = stretchy.ruleSpan(className, options);
-    line.height = thickness || options.fontMetrics().defaultRuleThickness;
-    line.style.height = line.height + "em";
-    line.maxFontSize = 1.0;
-    return line;
-};
-
-groupTypes.overline = function(group, options) {
-    // Overlines are handled in the TeXbook pg 443, Rule 9.
-
-    // Build the inner group in the cramped style.
-    const innerGroup = buildGroup(group.value.body,
-            options.havingCrampedStyle());
-
-    // Create the line above the body
-    const line = makeLineSpan("overline-line", options);
-
-    // Generate the vlist, with the appropriate kerns
-    const vlist = buildCommon.makeVList({
-        positionType: "firstBaseline",
-        children: [
-            {type: "elem", elem: innerGroup},
-            {type: "kern", size: 3 * line.height},
-            {type: "elem", elem: line},
-            {type: "kern", size: line.height},
-        ],
-    }, options);
-
-    return makeSpan(["mord", "overline"], [vlist], options);
-};
-
-groupTypes.underline = function(group, options) {
-    // Underlines are handled in the TeXbook pg 443, Rule 10.
-    // Build the inner group.
-    const innerGroup = buildGroup(group.value.body, options);
-
-    // Create the line above the body
-    const line = makeLineSpan("underline-line", options);
-
-    // Generate the vlist, with the appropriate kerns
-    const vlist = buildCommon.makeVList({
-        positionType: "top",
-        positionData: innerGroup.height,
-        children: [
-            {type: "kern", size: line.height},
-            {type: "elem", elem: line},
-            {type: "kern", size: 3 * line.height},
-            {type: "elem", elem: innerGroup},
-        ],
-    }, options);
-
-    return makeSpan(["mord", "underline"], [vlist], options);
-};
-
 groupTypes.sqrt = function(group, options) {
     // Square roots are handled in the TeXbook pg. 443, Rule 11.
 
@@ -705,36 +648,6 @@ groupTypes.verb = function(group, options) {
         body, newOptions);
 };
 
-groupTypes.rule = function(group, options) {
-    // Make an empty span for the rule
-    const rule = makeSpan(["mord", "rule"], [], options);
-
-    // Calculate the shift, width, and height of the rule, and account for units
-    let shift = 0;
-    if (group.value.shift) {
-        shift = calculateSize(group.value.shift, options);
-    }
-
-    const width = calculateSize(group.value.width, options);
-    const height = calculateSize(group.value.height, options);
-
-    // Style the rule to the right size
-    rule.style.borderRightWidth = width + "em";
-    rule.style.borderTopWidth = height + "em";
-    rule.style.bottom = shift + "em";
-
-    // Record the height and width
-    rule.width = width;
-    rule.height = height + shift;
-    rule.depth = -shift;
-    // Font size is the number large enough that the browser will
-    // reserve at least `absHeight` space above the baseline.
-    // The 1.125 factor was empirically determined
-    rule.maxFontSize = height * 1.125 * options.sizeMultiplier;
-
-    return rule;
-};
-
 groupTypes.accent = function(group, options) {
     // Accents are handled in the TeXbook pg. 443, rule 12.
     let base = group.value.base;

src/buildMathML.js

@@ -359,32 +359,6 @@ groupTypes.verb = function(group, options) {
     return node;
 };
 
-groupTypes.overline = function(group, options) {
-    const operator = new mathMLTree.MathNode(
-        "mo", [new mathMLTree.TextNode("\u203e")]);
-    operator.setAttribute("stretchy", "true");
-
-    const node = new mathMLTree.MathNode(
-        "mover",
-        [buildGroup(group.value.body, options), operator]);
-    node.setAttribute("accent", "true");
-
-    return node;
-};
-
-groupTypes.underline = function(group, options) {
-    const operator = new mathMLTree.MathNode(
-        "mo", [new mathMLTree.TextNode("\u203e")]);
-    operator.setAttribute("stretchy", "true");
-
-    const node = new mathMLTree.MathNode(
-        "munder",
-        [buildGroup(group.value.body, options), operator]);
-    node.setAttribute("accentunder", "true");
-
-    return node;
-};
-
 groupTypes.accentUnder = function(group, options) {
     const accentNode = stretchy.mathMLnode(group.value.label);
     const node = new mathMLTree.MathNode(
@@ -460,14 +434,6 @@ groupTypes.xArrow = function(group, options) {
     return node;
 };
 
-groupTypes.rule = function(group) {
-    // TODO(emily): Figure out if there's an actual way to draw black boxes
-    // in MathML.
-    const node = new mathMLTree.MathNode("mrow");
-
-    return node;
-};
-
 groupTypes.mclass = function(group, options) {
     const inner = buildExpression(group.value.value, options);
     return new mathMLTree.MathNode("mstyle", inner);

src/domTree.js

@@ -59,6 +59,7 @@ class span implements CombinableDomNode {
     children: DomChildNode[];
     height: number;
     depth: number;
+    width: ?number;
     maxFontSize: number;
     style: {[string]: string};
     attributes: {[string]: string};

src/functions.js

@@ -124,44 +124,11 @@ defineFunction(["\\fcolorbox"], {
     };
 });
 
-// An overline
-defineFunction(["\\overline"], {
-    numArgs: 1,
-}, function(context, args) {
-    const body = args[0];
-    return {
-        type: "overline",
-        body: body,
-    };
-});
+import "./functions/overline";
 
-// An underline
-defineFunction(["\\underline"], {
-    numArgs: 1,
-}, function(context, args) {
-    const body = args[0];
-    return {
-        type: "underline",
-        body: body,
-    };
-});
+import "./functions/underline";
 
-// A box of the width and height
-defineFunction(["\\rule"], {
-    numArgs: 2,
-    numOptionalArgs: 1,
-    argTypes: ["size", "size", "size"],
-}, function(context, args, optArgs) {
-    const shift = optArgs[0];
-    const width = args[0];
-    const height = args[1];
-    return {
-        type: "rule",
-        shift: shift && shift.value,
-        width: width.value,
-        height: height.value,
-    };
-});
+import "./functions/rule";
 
 import "./functions/kern";
 

src/functions/genfrac.js

@@ -93,7 +93,7 @@ defineFunction({
         let ruleWidth;
         let ruleSpacing;
         if (group.value.hasBarLine) {
-            rule = html.makeLineSpan("frac-line", options);
+            rule = buildCommon.makeLineSpan("frac-line", options);
             ruleWidth = rule.height;
             ruleSpacing = rule.height;
         } else {

src/functions/overline.js

@@ -0,0 +1,57 @@
+// @flow
+import defineFunction from "../defineFunction";
+import buildCommon from "../buildCommon";
+import mathMLTree from "../mathMLTree";
+
+import * as html from "../buildHTML";
+import * as mml from "../buildMathML";
+
+defineFunction({
+    type: "overline",
+    names: ["\\overline"],
+    props: {
+        numArgs: 1,
+    },
+    handler(context, args) {
+        const body = args[0];
+        return {
+            type: "overline",
+            body: body,
+        };
+    },
+    htmlBuilder(group, options) {
+        // Overlines are handled in the TeXbook pg 443, Rule 9.
+
+        // Build the inner group in the cramped style.
+        const innerGroup = html.buildGroup(group.value.body,
+            options.havingCrampedStyle());
+
+        // Create the line above the body
+        const line = buildCommon.makeLineSpan("overline-line", options);
+
+        // Generate the vlist, with the appropriate kerns
+        const vlist = buildCommon.makeVList({
+            positionType: "firstBaseline",
+            children: [
+                {type: "elem", elem: innerGroup},
+                {type: "kern", size: 3 * line.height},
+                {type: "elem", elem: line},
+                {type: "kern", size: line.height},
+            ],
+        }, options);
+
+        return buildCommon.makeSpan(["mord", "overline"], [vlist], options);
+    },
+    mathmlBuilder(group, options) {
+        const operator = new mathMLTree.MathNode(
+            "mo", [new mathMLTree.TextNode("\u203e")]);
+        operator.setAttribute("stretchy", "true");
+
+        const node = new mathMLTree.MathNode(
+            "mover",
+            [mml.buildGroup(group.value.body, options), operator]);
+        node.setAttribute("accent", "true");
+
+        return node;
+    },
+});

src/functions/rule.js

@@ -0,0 +1,62 @@
+// @flow
+import buildCommon from "../buildCommon";
+import defineFunction from "../defineFunction";
+import mathMLTree from "../mathMLTree";
+import {calculateSize} from "../units";
+
+defineFunction({
+    type: "rule",
+    names: ["\\rule"],
+    props: {
+        numArgs: 2,
+        numOptionalArgs: 1,
+        argTypes: ["size", "size", "size"],
+    },
+    handler(context, args, optArgs) {
+        const shift = optArgs[0];
+        const width = args[0];
+        const height = args[1];
+        return {
+            type: "rule",
+            shift: shift && shift.value,
+            width: width.value,
+            height: height.value,
+        };
+    },
+    htmlBuilder(group, options) {
+        // Make an empty span for the rule
+        const rule = buildCommon.makeSpan(["mord", "rule"], [], options);
+
+        // Calculate the shift, width, and height of the rule, and account for units
+        let shift = 0;
+        if (group.value.shift) {
+            shift = calculateSize(group.value.shift, options);
+        }
+
+        const width = calculateSize(group.value.width, options);
+        const height = calculateSize(group.value.height, options);
+
+        // Style the rule to the right size
+        rule.style.borderRightWidth = width + "em";
+        rule.style.borderTopWidth = height + "em";
+        rule.style.bottom = shift + "em";
+
+        // Record the height and width
+        rule.width = width;
+        rule.height = height + shift;
+        rule.depth = -shift;
+        // Font size is the number large enough that the browser will
+        // reserve at least `absHeight` space above the baseline.
+        // The 1.125 factor was empirically determined
+        rule.maxFontSize = height * 1.125 * options.sizeMultiplier;
+
+        return rule;
+    },
+    mathmlBuilder(group, options) {
+        // TODO(emily): Figure out if there's an actual way to draw black boxes
+        // in MathML.
+        const node = new mathMLTree.MathNode("mrow");
+
+        return node;
+    },
+});

src/functions/underline.js

@@ -0,0 +1,56 @@
+// @flow
+import defineFunction from "../defineFunction";
+import buildCommon from "../buildCommon";
+import mathMLTree from "../mathMLTree";
+
+import * as html from "../buildHTML";
+import * as mml from "../buildMathML";
+
+defineFunction({
+    type: "underline",
+    names: ["\\underline"],
+    props: {
+        numArgs: 1,
+    },
+    handler(context, args) {
+        const body = args[0];
+        return {
+            type: "underline",
+            body: body,
+        };
+    },
+    htmlBuilder(group, options) {
+        // Underlines are handled in the TeXbook pg 443, Rule 10.
+        // Build the inner group.
+        const innerGroup = html.buildGroup(group.value.body, options);
+
+        // Create the line above the body
+        const line = buildCommon.makeLineSpan("underline-line", options);
+
+        // Generate the vlist, with the appropriate kerns
+        const vlist = buildCommon.makeVList({
+            positionType: "top",
+            positionData: innerGroup.height,
+            children: [
+                {type: "kern", size: line.height},
+                {type: "elem", elem: line},
+                {type: "kern", size: 3 * line.height},
+                {type: "elem", elem: innerGroup},
+            ],
+        }, options);
+
+        return buildCommon.makeSpan(["mord", "underline"], [vlist], options);
+    },
+    mathmlBuilder(group, options) {
+        const operator = new mathMLTree.MathNode(
+            "mo", [new mathMLTree.TextNode("\u203e")]);
+        operator.setAttribute("stretchy", "true");
+
+        const node = new mathMLTree.MathNode(
+            "munder",
+            [mml.buildGroup(group.value.body, options), operator]);
+        node.setAttribute("accentunder", "true");
+
+        return node;
+    },
+});