Files
bentopdf/src/js/logic/compare-pdfs-page.ts
2025-12-11 19:34:14 +05:30

307 lines
11 KiB
TypeScript

import { showLoader, hideLoader, showAlert } from '../ui.js';
import { getPDFDocument } from '../utils/helpers.js';
import { icons, createIcons } from 'lucide';
import * as pdfjsLib from 'pdfjs-dist';
pdfjsLib.GlobalWorkerOptions.workerSrc = new URL('pdfjs-dist/build/pdf.worker.min.mjs', import.meta.url).toString();
interface CompareState {
pdfDoc1: pdfjsLib.PDFDocumentProxy | null;
pdfDoc2: pdfjsLib.PDFDocumentProxy | null;
currentPage: number;
viewMode: 'overlay' | 'side-by-side';
isSyncScroll: boolean;
}
const pageState: CompareState = {
pdfDoc1: null,
pdfDoc2: null,
currentPage: 1,
viewMode: 'overlay',
isSyncScroll: true,
};
async function renderPage(
pdfDoc: pdfjsLib.PDFDocumentProxy,
pageNum: number,
canvas: HTMLCanvasElement,
container: HTMLElement
) {
const page = await pdfDoc.getPage(pageNum);
const containerWidth = container.clientWidth - 2;
const viewport = page.getViewport({ scale: 1.0 });
const scale = containerWidth / viewport.width;
const scaledViewport = page.getViewport({ scale: scale });
canvas.width = scaledViewport.width;
canvas.height = scaledViewport.height;
await page.render({
canvasContext: canvas.getContext('2d')!,
viewport: scaledViewport,
canvas
}).promise;
}
async function renderBothPages() {
if (!pageState.pdfDoc1 || !pageState.pdfDoc2) return;
showLoader(`Loading page ${pageState.currentPage}...`);
const canvas1 = document.getElementById('canvas-compare-1') as HTMLCanvasElement;
const canvas2 = document.getElementById('canvas-compare-2') as HTMLCanvasElement;
const panel1 = document.getElementById('panel-1') as HTMLElement;
const panel2 = document.getElementById('panel-2') as HTMLElement;
const wrapper = document.getElementById('compare-viewer-wrapper') as HTMLElement;
const container1 = pageState.viewMode === 'overlay' ? wrapper : panel1;
const container2 = pageState.viewMode === 'overlay' ? wrapper : panel2;
await Promise.all([
renderPage(
pageState.pdfDoc1,
Math.min(pageState.currentPage, pageState.pdfDoc1.numPages),
canvas1,
container1
),
renderPage(
pageState.pdfDoc2,
Math.min(pageState.currentPage, pageState.pdfDoc2.numPages),
canvas2,
container2
),
]);
updateNavControls();
hideLoader();
}
function updateNavControls() {
const maxPages = Math.max(
pageState.pdfDoc1?.numPages || 0,
pageState.pdfDoc2?.numPages || 0
);
const currentDisplay = document.getElementById('current-page-display-compare');
const totalDisplay = document.getElementById('total-pages-display-compare');
const prevBtn = document.getElementById('prev-page-compare') as HTMLButtonElement;
const nextBtn = document.getElementById('next-page-compare') as HTMLButtonElement;
if (currentDisplay) currentDisplay.textContent = pageState.currentPage.toString();
if (totalDisplay) totalDisplay.textContent = maxPages.toString();
if (prevBtn) prevBtn.disabled = pageState.currentPage <= 1;
if (nextBtn) nextBtn.disabled = pageState.currentPage >= maxPages;
}
function setViewMode(mode: 'overlay' | 'side-by-side') {
pageState.viewMode = mode;
const wrapper = document.getElementById('compare-viewer-wrapper');
const overlayControls = document.getElementById('overlay-controls');
const sideControls = document.getElementById('side-by-side-controls');
const btnOverlay = document.getElementById('view-mode-overlay');
const btnSide = document.getElementById('view-mode-side');
const canvas2 = document.getElementById('canvas-compare-2') as HTMLCanvasElement;
const opacitySlider = document.getElementById('opacity-slider') as HTMLInputElement;
if (mode === 'overlay') {
if (wrapper) wrapper.className = 'compare-viewer-wrapper overlay-mode bg-gray-900 rounded-lg border border-gray-700 min-h-[400px] relative';
if (overlayControls) overlayControls.classList.remove('hidden');
if (sideControls) sideControls.classList.add('hidden');
if (btnOverlay) {
btnOverlay.classList.add('bg-indigo-600');
btnOverlay.classList.remove('bg-gray-700');
}
if (btnSide) {
btnSide.classList.remove('bg-indigo-600');
btnSide.classList.add('bg-gray-700');
}
if (canvas2 && opacitySlider) canvas2.style.opacity = opacitySlider.value;
} else {
if (wrapper) wrapper.className = 'compare-viewer-wrapper side-by-side-mode bg-gray-900 rounded-lg border border-gray-700 min-h-[400px]';
if (overlayControls) overlayControls.classList.add('hidden');
if (sideControls) sideControls.classList.remove('hidden');
if (btnOverlay) {
btnOverlay.classList.remove('bg-indigo-600');
btnOverlay.classList.add('bg-gray-700');
}
if (btnSide) {
btnSide.classList.add('bg-indigo-600');
btnSide.classList.remove('bg-gray-700');
}
if (canvas2) canvas2.style.opacity = '1';
}
renderBothPages();
}
async function handleFileInput(inputId: string, docKey: 'pdfDoc1' | 'pdfDoc2', displayId: string) {
const fileInput = document.getElementById(inputId) as HTMLInputElement;
const dropZone = document.getElementById(`drop-zone-${inputId.slice(-1)}`);
async function handleFile(file: File) {
if (!file || file.type !== 'application/pdf') {
showAlert('Invalid File', 'Please select a valid PDF file.');
return;
}
const displayDiv = document.getElementById(displayId);
if (displayDiv) {
displayDiv.innerHTML = '';
const icon = document.createElement('i');
icon.setAttribute('data-lucide', 'check-circle');
icon.className = 'w-10 h-10 mb-3 text-green-500';
const p = document.createElement('p');
p.className = 'text-sm text-gray-300 truncate';
p.textContent = file.name;
displayDiv.append(icon, p);
createIcons({ icons });
}
try {
showLoader(`Loading ${file.name}...`);
const arrayBuffer = await file.arrayBuffer();
pageState[docKey] = await getPDFDocument({ data: arrayBuffer }).promise;
if (pageState.pdfDoc1 && pageState.pdfDoc2) {
const compareViewer = document.getElementById('compare-viewer');
if (compareViewer) compareViewer.classList.remove('hidden');
pageState.currentPage = 1;
await renderBothPages();
}
} catch (e) {
showAlert('Error', 'Could not load PDF. It may be corrupt or password-protected.');
console.error(e);
} finally {
hideLoader();
}
}
if (fileInput) {
fileInput.addEventListener('change', function (e) {
const files = (e.target as HTMLInputElement).files;
if (files && files[0]) handleFile(files[0]);
});
}
if (dropZone) {
dropZone.addEventListener('dragover', function (e) {
e.preventDefault();
});
dropZone.addEventListener('drop', function (e) {
e.preventDefault();
const files = e.dataTransfer?.files;
if (files && files[0]) handleFile(files[0]);
});
}
}
document.addEventListener('DOMContentLoaded', function () {
const backBtn = document.getElementById('back-to-tools');
if (backBtn) {
backBtn.addEventListener('click', function () {
window.location.href = import.meta.env.BASE_URL;
});
}
handleFileInput('file-input-1', 'pdfDoc1', 'file-display-1');
handleFileInput('file-input-2', 'pdfDoc2', 'file-display-2');
const prevBtn = document.getElementById('prev-page-compare');
const nextBtn = document.getElementById('next-page-compare');
if (prevBtn) {
prevBtn.addEventListener('click', function () {
if (pageState.currentPage > 1) {
pageState.currentPage--;
renderBothPages();
}
});
}
if (nextBtn) {
nextBtn.addEventListener('click', function () {
const maxPages = Math.max(
pageState.pdfDoc1?.numPages || 0,
pageState.pdfDoc2?.numPages || 0
);
if (pageState.currentPage < maxPages) {
pageState.currentPage++;
renderBothPages();
}
});
}
const btnOverlay = document.getElementById('view-mode-overlay');
const btnSide = document.getElementById('view-mode-side');
if (btnOverlay) {
btnOverlay.addEventListener('click', function () {
setViewMode('overlay');
});
}
if (btnSide) {
btnSide.addEventListener('click', function () {
setViewMode('side-by-side');
});
}
const flickerBtn = document.getElementById('flicker-btn');
const canvas2 = document.getElementById('canvas-compare-2') as HTMLCanvasElement;
const opacitySlider = document.getElementById('opacity-slider') as HTMLInputElement;
// Track flicker state
let flickerVisible = true;
if (flickerBtn && canvas2) {
flickerBtn.addEventListener('click', function () {
flickerVisible = !flickerVisible;
canvas2.style.transition = 'opacity 150ms ease-in-out';
canvas2.style.opacity = flickerVisible ? (opacitySlider?.value || '0.5') : '0';
});
}
if (opacitySlider && canvas2) {
opacitySlider.addEventListener('input', function () {
flickerVisible = true; // Reset flicker state when slider changes
canvas2.style.transition = '';
canvas2.style.opacity = opacitySlider.value;
});
}
const panel1 = document.getElementById('panel-1');
const panel2 = document.getElementById('panel-2');
const syncToggle = document.getElementById('sync-scroll-toggle') as HTMLInputElement;
if (syncToggle) {
syncToggle.addEventListener('change', function () {
pageState.isSyncScroll = syncToggle.checked;
});
}
let scrollingPanel: HTMLElement | null = null;
if (panel1 && panel2) {
panel1.addEventListener('scroll', function () {
if (pageState.isSyncScroll && scrollingPanel !== panel2) {
scrollingPanel = panel1;
panel2.scrollTop = panel1.scrollTop;
setTimeout(function () { scrollingPanel = null; }, 100);
}
});
panel2.addEventListener('scroll', function () {
if (pageState.isSyncScroll && scrollingPanel !== panel1) {
scrollingPanel = panel2;
panel1.scrollTop = panel2.scrollTop;
setTimeout(function () { scrollingPanel = null; }, 100);
}
});
}
createIcons({ icons });
});