From dd112a5b5f1d0e6dc6b34fc8b4a9e05a474312d6 Mon Sep 17 00:00:00 2001
From: Yaotian-Liu <yaotian_liu@gmx.com>
Date: Tue, 4 Jun 2024 18:22:37 -0700
Subject: [PATCH] feat: Update theme detector

---
 main.ts      |  7 ++++++-
 src/theme.ts | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 src/theme.ts

diff --git a/main.ts b/main.ts
index 499d6d1..8a8143f 100644
--- a/main.ts
+++ b/main.ts
@@ -14,6 +14,7 @@ import {
 } from "src/latex_translator";
 import { createExportButton } from "src/export_button";
 import { extractInlineMacros } from "src/inline_macro";
+import { setObserver, detachObserver } from "src/theme";
 
 import * as pseudocode from "pseudocode";
 
@@ -63,6 +64,8 @@ export default class PseudocodePlugin extends Plugin {
 	async onload() {
 		await this.loadSettings();
 
+		setObserver();
+
 		if (this.settings.preambleEnabled) {
 			console.log("Preamble is enabled.");
 			await this.loadPreamble();
@@ -89,7 +92,9 @@ export default class PseudocodePlugin extends Plugin {
 		});
 	}
 
-	onunload() {}
+	onunload() {
+		detachObserver();
+	}
 
 	async loadPreamble() {
 		try {
diff --git a/src/theme.ts b/src/theme.ts
new file mode 100644
index 0000000..e85b843
--- /dev/null
+++ b/src/theme.ts
@@ -0,0 +1,55 @@
+// Reference: https://forum.obsidian.md/t/obsidian-publish-api-how-to-track-changing-theme/73637/4
+
+export const themeObserver = new MutationObserver(function (mutations) {
+	mutations.forEach(function (mutation) {
+		const target = mutation.target as HTMLElement;
+		if (
+			// dark -> dark & light -> light
+			mutation.oldValue?.contains('theme-dark') &&
+			!mutation.oldValue?.contains('theme-light') && // key line, avoid calling twice
+			target.classList.value.contains('theme-light')
+		) {
+			console.log('light theme detected');
+			setTheme();
+		} else if (
+			// light -> empty -> dark
+			mutation.oldValue?.contains('theme-light') && // key line, avoid calling twice
+			!mutation.oldValue?.contains('theme-dark') &&
+			target.classList.value.contains('theme-dark')
+		) {
+			console.log('dark theme detected');
+			setTheme();
+		}
+	});
+});
+
+function setTheme() {
+	const bodyElement = document.body;
+	const backgroundValue = getComputedStyle(bodyElement).getPropertyValue('--background-primary').trim();
+    const fontValue = getComputedStyle(bodyElement).getPropertyValue('--text-normal').trim();
+	console.log(getComputedStyle(document.documentElement));
+	console.log(backgroundValue, fontValue);
+
+	// Select all elements with the class 'ps-root'
+	const psRootElements = document.querySelectorAll('.ps-root');
+
+	// Loop through each element and modify the CSS properties
+	psRootElements.forEach(element => {
+		const htmlElement = element as HTMLElement;
+		htmlElement.style.backgroundColor = backgroundValue;
+		htmlElement.style.opacity = '1';
+		htmlElement.style.color = fontValue;
+	});
+}
+
+export const setObserver = () => {
+	themeObserver.observe(document.body, {
+		attributes: true,
+		attributeOldValue: true,
+		attributeFilter: ['class'],
+	});
+};
+
+export const detachObserver = () => {
+	themeObserver.disconnect();
+};
\ No newline at end of file