From 23fc0df1f33bd32456a73e09ddc16e19c52a3087 Mon Sep 17 00:00:00 2001
From: Erek Speed <melink14@gmail.com>
Date: Sun, 3 Apr 2022 14:12:21 +0900
Subject: [PATCH] fix(detection): Copy text affecting style properties of
 input/textarea elements when creating fake (#886)

Fixes #672
---
 extension/rikaicontent.ts           |  23 +++-
 extension/test/rikaicontent_test.ts | 183 ++++++++++++++++++++++++++++
 2 files changed, 202 insertions(+), 4 deletions(-)

diff --git a/extension/rikaicontent.ts b/extension/rikaicontent.ts
index 890e7369b..57a8f5fba 100644
--- a/extension/rikaicontent.ts
+++ b/extension/rikaicontent.ts
@@ -1066,11 +1066,26 @@ class RcxContent {
     } else {
       textValue = real.value;
     }
+    const realStyles = window.getComputedStyle(real, '');
     fake.innerText = textValue;
-    fake.style.cssText = document.defaultView!.getComputedStyle(
-      real,
-      ''
-    ).cssText;
+    // Text areas never visible collapse spaces so always set whiteSpace to pre-wrap
+    fake.style.whiteSpace = 'pre-wrap';
+    fake.style.font = realStyles.font;
+    fake.style.height = realRect.height + 'px';
+    // Without a width, the fake div will expand horizontally
+    fake.style.width = realRect.width + 'px';
+    // Padding moves text inwards so needs to be copied
+    fake.style.padding = realStyles.padding;
+    // Border also affects total width sometimes
+    fake.style.border = realStyles.border;
+    // Effects total width when padding and border are set.
+    fake.style.boxSizing = realStyles.boxSizing;
+    // The overflow property can add scrollbars which affects text placement.
+    fake.style.overflow = realStyles.overflow;
+    fake.style.letterSpacing = realStyles.letterSpacing;
+    // Japanese text is often not broken into words but this could be important for
+    // mixed language text.
+    fake.style.wordSpacing = realStyles.wordSpacing;
     fake.scrollTop = real.scrollTop;
     fake.scrollLeft = real.scrollLeft;
     fake.style.position = 'absolute';
diff --git a/extension/test/rikaicontent_test.ts b/extension/test/rikaicontent_test.ts
index 16004405e..d09363627 100644
--- a/extension/test/rikaicontent_test.ts
+++ b/extension/test/rikaicontent_test.ts
@@ -124,6 +124,179 @@ describe('RcxContent', function () {
           text: '生test',
         });
       });
+
+      it('triggers xsearch message when text area has custom font styles', function () {
+        const clock = sinon.useFakeTimers();
+        const measuringSpan = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<span style="font-size:32px">位の日本語訳・</span>'
+        ) as HTMLSpanElement;
+        const input = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<input style="font-size:32px" value="位の日本語訳・中国語訳にも" size="34"/>'
+        ) as HTMLInputElement;
+
+        triggerMousemoveAtElementStartWithOffset(input, {
+          x: measuringSpan.getBoundingClientRect().width + 1,
+          y: input.getBoundingClientRect().height / 2,
+        });
+        // Tick the clock forward to account for the popup delay.
+        clock.tick(1);
+
+        // This value is chosen via experimentation since it's hard to know exactly
+        // where a character is in an input element.
+        expect(chrome.runtime.sendMessage).to.have.been.calledWithMatch({
+          type: 'xsearch',
+          text: '中国語訳にも',
+        });
+      });
+
+      it('triggers xsearch message when text area has custom width and scrollbars', function () {
+        const clock = sinon.useFakeTimers();
+        const measuringDiv = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<div style="width:40px;height:auto;overflow-y:scroll">位の</div>'
+        ) as HTMLDivElement;
+        const input = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<textarea style="all:initial;width:40px;height:100px">位の日本語訳・中国語訳にも'
+        ) as HTMLTextAreaElement;
+
+        triggerMousemoveAtElementStartWithOffset(input, {
+          x: 0,
+          y: measuringDiv.getBoundingClientRect().height + 1,
+        });
+        // Tick the clock forward to account for the popup delay.
+        clock.tick(1);
+
+        expect(chrome.runtime.sendMessage).to.have.been.calledWithMatch({
+          type: 'xsearch',
+          text: '日本語訳・中国語訳にも',
+        });
+      });
+
+      it('does not trigger xsearch for text that should be truncated by custom height', function () {
+        const clock = sinon.useFakeTimers();
+        const measuringDiv = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<div style="width:40px;height:auto;overflow-y:scroll">位の日本語訳・中国語訳にも</div>'
+        ) as HTMLDivElement;
+        const input = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<textarea style="all:initial;width:40px;height:100px">位の日本語訳・中国語訳にも'
+        ) as HTMLTextAreaElement;
+
+        // Trigger at the the bottom of full length text even though the end should
+        // be truncated if height is honored.
+        triggerMousemoveAtElementStartWithOffset(input, {
+          x: 5,
+          y: measuringDiv.getBoundingClientRect().height - 1,
+        });
+        // Tick the clock forward to account for the popup delay.
+        clock.tick(1);
+
+        expect(chrome.runtime.sendMessage).to.have.not.been.called;
+      });
+
+      it('triggers xsearch message when text area has custom padding', function () {
+        const clock = sinon.useFakeTimers();
+        const padding = 20;
+        const input = insertHtmlIntoDomAndReturnFirstTextNode(
+          `<textarea style="padding:${padding}px">中国語訳にも`
+        ) as HTMLTextAreaElement;
+
+        triggerMousemoveAtElementStartWithOffset(input, {
+          x: padding + 1,
+          y: padding + 1,
+        });
+        // Tick the clock forward to account for the popup delay.
+        clock.tick(1);
+
+        expect(chrome.runtime.sendMessage).to.have.been.calledWithMatch({
+          type: 'xsearch',
+          text: '中国語訳にも',
+        });
+      });
+
+      it('triggers xsearch message when text area has custom border', function () {
+        const clock = sinon.useFakeTimers();
+        const border = 20;
+        const input = insertHtmlIntoDomAndReturnFirstTextNode(
+          `<textarea style="border:${border}px solid">中国語訳にも`
+        ) as HTMLTextAreaElement;
+
+        triggerMousemoveAtElementStartWithOffset(input, {
+          x: border + 1,
+          y: border + 1,
+        });
+        // Tick the clock forward to account for the popup delay.
+        clock.tick(1);
+
+        expect(chrome.runtime.sendMessage).to.have.been.calledWithMatch({
+          type: 'xsearch',
+          text: '中国語訳にも',
+        });
+      });
+
+      it('triggers xsearch message when above Japanese text preceded by consecutive spaces', function () {
+        const clock = sinon.useFakeTimers();
+        const measuringSpan = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<span style="white-space:pre-wrap">中国          </span>'
+        ) as HTMLDivElement;
+        const input = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<textarea style="all:initial;white-space:normal">中国          語訳にも'
+        ) as HTMLTextAreaElement;
+
+        triggerMousemoveAtElementStartWithOffset(input, {
+          x: measuringSpan.getBoundingClientRect().width + 1,
+          y: measuringSpan.getBoundingClientRect().height / 2,
+        });
+        // Tick the clock forward to account for the popup delay.
+        clock.tick(1);
+
+        expect(chrome.runtime.sendMessage).to.have.been.calledWithMatch({
+          type: 'xsearch',
+          text: '語訳にも',
+        });
+      });
+
+      it('triggers xsearch message when text area has custom letter-spacing', function () {
+        const clock = sinon.useFakeTimers();
+        const measuringSpan = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<span style="letter-spacing:10px">中国</span>'
+        ) as HTMLDivElement;
+        const input = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<textarea style="all:initial;letter-spacing:10px">中国語訳にも'
+        ) as HTMLTextAreaElement;
+
+        triggerMousemoveAtElementStartWithOffset(input, {
+          x: measuringSpan.getBoundingClientRect().width + 1,
+          y: measuringSpan.getBoundingClientRect().height / 2,
+        });
+        // Tick the clock forward to account for the popup delay.
+        clock.tick(1);
+
+        expect(chrome.runtime.sendMessage).to.have.been.calledWithMatch({
+          type: 'xsearch',
+          text: '語訳にも',
+        });
+      });
+
+      it('triggers xsearch message when text area has custom word-spacing', function () {
+        const clock = sinon.useFakeTimers();
+        const measuringSpan = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<span style="word-spacing:10px">a a a 中国</span>'
+        ) as HTMLDivElement;
+        const input = insertHtmlIntoDomAndReturnFirstTextNode(
+          '<textarea style="all:initial;word-spacing:10px">a a a 中国語訳にも'
+        ) as HTMLTextAreaElement;
+
+        triggerMousemoveAtElementStartWithOffset(input, {
+          x: measuringSpan.getBoundingClientRect().width + 1,
+          y: measuringSpan.getBoundingClientRect().height / 2,
+        });
+        // Tick the clock forward to account for the popup delay.
+        clock.tick(1);
+
+        expect(chrome.runtime.sendMessage).to.have.been.calledWithMatch({
+          type: 'xsearch',
+          text: '語訳にも',
+        });
+      });
     });
 
     describe('with Google Docs annotated canvas', function () {
@@ -796,6 +969,16 @@ function triggerMousemoveAtElementCenter(element: Element) {
   });
 }
 
+function triggerMousemoveAtElementStartWithOffset(
+  element: Element,
+  offset: { x: number; y: number }
+) {
+  simulant.fire(element, 'mousemove', {
+    clientX: Math.ceil(element.getBoundingClientRect().left + offset.x),
+    clientY: Math.ceil(element.getBoundingClientRect().top + offset.y),
+  });
+}
+
 function insertHtmlIntoDomAndReturnFirstTextNode(htmlString: string): Node {
   const template = document.createElement('template');
   template.innerHTML = htmlString;