From da4858a76e4faad6e5ee49f9cebf80e3fa981de4 Mon Sep 17 00:00:00 2001
From: Benoit Averty <benoit.averty@gmail.com>
Date: Fri, 18 Nov 2016 02:12:23 +0100
Subject: [PATCH] Unicode Support / Cursor issues Fix (#740)

* Add container with a fixed width around unicode characters

* Make container width dynamic and fix wide chars clipping issue

* Finer control on the creation of containers for text inserted in the terminal
---
 lib/hterm.js | 102 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 package.json |   3 +-
 2 files changed, 102 insertions(+), 3 deletions(-)

diff --git a/lib/hterm.js b/lib/hterm.js
index d56febdf..eb4ffd5e 100644
--- a/lib/hterm.js
+++ b/lib/hterm.js
@@ -1,10 +1,16 @@
 import {hterm, lib} from 'hterm-umdjs';
-import fromCharCode from './utils/key-code';
+import runes from 'runes';
 
-const selection = require('./utils/selection');
+import fromCharCode from './utils/key-code';
+import selection from './utils/selection';
 
 hterm.defaultStorage = new lib.Storage.Memory();
 
+// The current width of characters rendered in hterm
+let charWidth;
+// Containers to resize when char width changes
+const containers = [];
+
 // Provide selectAll to terminal viewport
 hterm.Terminal.prototype.selectAll = function () {
   // We need to clear the DOM range to reset anchorNode
@@ -12,6 +18,25 @@ hterm.Terminal.prototype.selectAll = function () {
   selection.all(this);
 };
 
+const oldSetFontSize = hterm.Terminal.prototype.setFontSize;
+hterm.Terminal.prototype.setFontSize = function (px) {
+  oldSetFontSize.call(this, px);
+  charWidth = this.scrollPort_.characterSize.width;
+  // @TODO Maybe clear old spans from the list of spans to resize ?
+  // Resize all containers to match the new whar width.
+  containers.forEach(container => {
+    if (container && container.style) {
+      container.style.width = `${container.wcNode ? charWidth * 2 : charWidth}px`;
+    }
+  });
+};
+
+const oldSyncFontFamily = hterm.Terminal.prototype.syncFontFamily;
+hterm.Terminal.prototype.syncFontFamily = function () {
+  oldSyncFontFamily.call(this);
+  this.setFontSize();
+};
+
 // override double click behavior to copy
 const oldMouse = hterm.Terminal.prototype.onMouse_;
 hterm.Terminal.prototype.onMouse_ = function (e) {
@@ -23,6 +48,79 @@ hterm.Terminal.prototype.onMouse_ = function (e) {
   return oldMouse.call(this, e);
 };
 
+function containsNonLatinCodepoints(s) {
+  return /[^\u0000-\u00ff]/.test(s);
+}
+hterm.Terminal.IO.prototype.writeUTF8 = function (string) {
+  if (this.terminal_.io !== this) {
+    throw new Error('Attempt to print from inactive IO object.');
+  }
+
+  if (containsNonLatinCodepoints(string)) {
+    const splitString = runes(string);
+    const length = splitString.length;
+    this.terminal_.getTextAttributes().hasUnicode = true;
+
+    for (let curChar = 0; curChar <= length; curChar++) {
+      this.terminal_.interpret(splitString[curChar]);
+    }
+
+    this.terminal_.getTextAttributes().hasUnicode = false;
+  } else {
+    this.terminal_.interpret(string);
+  }
+};
+
+const oldCreateContainer = hterm.TextAttributes.prototype.createContainer;
+hterm.TextAttributes.prototype.createContainer = function (text) {
+  const container = oldCreateContainer.call(this, text);
+
+  if (container.style && text.length === 1 && containsNonLatinCodepoints(text)) {
+    container.style.width = `${container.wcNode ? charWidth * 2 : charWidth}px`;
+    container.style.display = 'inline-block';
+
+    // If the container has unicode text, the char can overlap neigbouring containers. We need
+    // to ensure that the text is not hidden behind other containers.
+    container.style.overflow = 'visible';
+    container.style.position = 'relative';
+
+    // Remember this container to resize it later when font size changes.
+    containers.push(container);
+  }
+
+  return container;
+};
+
+// Do not match containers when one of them has unicode text (unicode chars need to be alone in their containers)
+const oldMatchesContainer = hterm.TextAttributes.prototype.matchesContainer;
+hterm.TextAttributes.prototype.matchesContainer = function (obj) {
+  const content = typeof obj === 'string' ? obj : obj.textContent;
+  if (containsNonLatinCodepoints(content)) {
+    return false;
+  }
+
+  if (this.hasUnicode) {
+    return false;
+  }
+
+  return oldMatchesContainer.call(this, obj);
+};
+
+/**
+ * Override 'containersMatch' so that containers with unicode do not match anything.
+ */
+const oldContainersMatch = hterm.TextAttributes.containersMatch;
+hterm.TextAttributes.containersMatch = function (obj1, obj2) {
+  const content1 = typeof obj1 === 'string' ? obj1 : obj1.textContent;
+  const content2 = typeof obj2 === 'string' ? obj2 : obj2.textContent;
+
+  if (containsNonLatinCodepoints(content1) || containsNonLatinCodepoints(content2)) {
+    return false;
+  }
+
+  return oldContainersMatch(obj1, obj2);
+};
+
 // there's no option to turn off the size overlay
 hterm.Terminal.prototype.overlaySize = function () {};
 
diff --git a/package.json b/package.json
index 4d5544a0..39d22557 100644
--- a/package.json
+++ b/package.json
@@ -87,7 +87,8 @@
     "reselect": "2.5.4",
     "seamless-immutable": "6.1.3",
     "semver": "5.3.0",
-    "uuid": "2.0.2"
+    "uuid": "2.0.2",
+    "runes": "^0.3.0"
   },
   "devDependencies": {
     "ava": "^0.16.0",