Files
lua-scripts-w-api/data/website_gallery/js/modal.js
2025-12-18 08:02:43 +01:00

356 lines
10 KiB
JavaScript

/*
copyright (c) 2025 Tino Mettler
darktable is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
darktable is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this software. If not, see <http://www.gnu.org/licenses/>.
*/
const container = document.querySelector('.slide-container');
const slides = {
prev: document.getElementById('prev'),
current: document.getElementById('current'),
next: document.getElementById('next')
};
const prevArrow = document.getElementById('prevArrow');
const nextArrow = document.getElementById('nextArrow');
let startX = 0;
let startY = 0;
let isDragging = false; // For swipe navigation
let isZoomed = false;
let isPanning = false; // Panning in zoomed state
let hasPanned = false;
let translateX = 0;
let translateY = 0;
let currentScale = 1;
let img;
let baseWidth, baseHeight; // Image dimensions before zoom
let scaledWidth, scaledHeight;
const images = gallery_data.images;
function updateCounter(index) {
const counter = document.getElementById('counter');
counter.textContent = (index + 1) + ' / ' + images.length;
}
function updateBoundaries() {
containerRect = container.getBoundingClientRect();
// Calculate the actual scaled dimensions based on the base (pre-zoom) size
scaledWidth = baseWidth * currentScale;
scaledHeight = baseHeight * currentScale;
}
function limitPanning(proposedX, proposedY) {
const maxX = 0;
const minX = baseWidth - scaledWidth;
const maxY = 0;
const minY = baseHeight - scaledHeight;
let constrainedX = proposedX;
let constrainedY = proposedY;
// Apply constraints
if (scaledWidth > baseWidth) {
// Image wider than original - constrain panning
constrainedX = Math.max(minX, Math.min(maxX, proposedX));
} else {
// Image narrower than original - center it
constrainedX = (baseWidth - scaledWidth) / 2;
}
if (scaledHeight > baseHeight) {
// Image taller than original - constrain panning
constrainedY = Math.max(minY, Math.min(maxY, proposedY));
} else {
// Image shorter than original - center it
constrainedY = (baseHeight - scaledHeight) / 2;
}
return {
x: constrainedX,
y: constrainedY
};
}
function handleZoom(e) {
// If we were actually panning, don't zoom
if (hasPanned) {
isPanning = false;
hasPanned = false;
return;
}
// If we're zoomed and haven't panned, zoom out
if (isZoomed) {
img.classList.add('zooming');
translateX = 0;
translateY = 0;
currentScale = 1;
img.style.transform = 'none';
container.classList.remove('zoomed');
isZoomed = false;
updateNavigationState();
setTimeout(() => {
img.classList.remove('zooming');
}, 200);
return;
}
// Zoom in at clicked/tapped point
if (!isZoomed) {
const rect = img.getBoundingClientRect();
const x = e.clientX - rect.left;
const y = e.clientY - rect.top;
// Store the base (pre-zoom) dimensions and offset
baseWidth = rect.width;
baseHeight = rect.height;
// Calculate the scale for 1:1 pixel zoom
currentScale = img.naturalWidth / rect.width;
// Calculate the translation needed to keep clicked point under cursor
// After scaling, the point at (x, y) will be at (x * currentScale, y * currentScale)
// We want it to remain at (e.clientX - rect.left, e.clientY - rect.top)
translateX = e.clientX - rect.left - (x * currentScale);
translateY = e.clientY - rect.top - (y * currentScale);
updateBoundaries();
const limited = limitPanning(translateX, translateY);
translateX = limited.x;
translateY = limited.y;
img.classList.add('zooming');
img.style.transform = `translate(${translateX}px, ${translateY}px) scale(${currentScale})`;
container.classList.add('zoomed');
setTimeout(() => {
img.classList.remove('zooming');
}, 200);
}
isZoomed = true;
updateNavigationState();
}
function createImageElement(imageData) {
if (!imageData) return null;
const img = new Image();
img.src = imageData.filename;
img.width = imageData.width;
img.height = imageData.height;
img.addEventListener('dragstart', (e) => e.preventDefault());
return img;
}
function loadSlides() {
slides.prev.innerHTML = '';
slides.current.innerHTML = '';
slides.next.innerHTML = '';
if (currentIndex > 0) {
const prevImg = createImageElement(images[currentIndex - 1]);
if (prevImg) slides.prev.appendChild(prevImg);
}
const currentImg = createImageElement(images[currentIndex]);
if (currentImg) {
img = currentImg;
slides.current.appendChild(currentImg);
}
if (currentIndex < images.length - 1) {
const nextImg = createImageElement(images[currentIndex + 1]);
if (nextImg) slides.next.appendChild(nextImg);
}
updateCounter(currentIndex)
updateNavigationState();
}
function updateNavigationState() {
prevArrow.style.visibility = (currentIndex === 0 || isZoomed) ? 'hidden' : 'visible';
nextArrow.style.visibility = (currentIndex === images.length - 1 || isZoomed) ? 'hidden' : 'visible';
}
async function showPreviousImage() {
if (currentIndex > 0 && !isZoomed) {
currentIndex--;
container.style.transition = 'transform 0.3s ease-out';
container.style.transform = 'translateX(0%)';
await waitForTransition();
container.style.transition = 'none';
container.style.transform = 'translateX(-33.333%)';
loadSlides();
}
}
async function showNextImage() {
if (currentIndex < images.length - 1 && !isZoomed) {
currentIndex++;
container.style.transition = 'transform 0.3s ease-out';
container.style.transform = 'translateX(-66.666%)';
await waitForTransition();
container.style.transition = 'none';
container.style.transform = 'translateX(-33.333%)';
loadSlides();
}
}
function handleTouchStart(e) {
if (isZoomed) return;
startX = e.touches[0].clientX;
isDragging = true;
container.style.transition = 'none';
}
function handleTouchMove(e) {
if (!isDragging || isZoomed) return;
const currentX = e.touches[0].clientX;
const diff = currentX - startX;
const baseOffset = -33.333;
const percentMoved = (diff / window.innerWidth) * 33.333;
container.style.transform = `translateX(${baseOffset + percentMoved}%)`;
}
async function handleTouchEnd(e) {
if (!isDragging)
if(isZoomed) {
handleZoom(e);
return;
}
isDragging = false;
const endX = e.changedTouches[0].clientX;
const diff = endX - startX;
const threshold = window.innerWidth * 0.2;
container.style.transition = 'transform 0.3s ease-out';
if (diff > threshold && currentIndex > 0) {
await showPreviousImage();
} else if (diff < -threshold && currentIndex < images.length - 1) {
await showNextImage();
} else {
container.style.transform = 'translateX(-33.333%)';
}
}
function handleKeyDown(e) {
if (isZoomed) return;
if (e.code === 'Space' || e.code === 'ArrowRight') {
e.preventDefault();
showNextImage();
} else if (e.code === 'Backspace' || e.code === 'ArrowLeft') {
e.preventDefault();
showPreviousImage();
}
}
function waitForTransition() {
return new Promise(resolve => {
container.addEventListener('transitionend', resolve, { once: true });
});
}
// Initialize
loadSlides();
// Navigation event listeners
container.addEventListener('touchstart', handleTouchStart);
container.addEventListener('touchmove', handleTouchMove);
container.addEventListener('touchend', handleTouchEnd);
container.addEventListener('click', handleZoom);
document.addEventListener('keydown', handleKeyDown);
prevArrow.addEventListener('click', showPreviousImage);
nextArrow.addEventListener('click', showNextImage);
// Mouse panning event listeners
container.addEventListener('mousedown', function(e) {
if (isZoomed && e.target.tagName === 'IMG') {
isPanning = true;
hasPanned = false;
updateBoundaries();
startX = e.clientX - translateX;
startY = e.clientY - translateY;
e.preventDefault();
container.style.cursor = 'grabbing';
}
});
window.addEventListener('mousemove', function(e) {
if (isPanning && isZoomed) {
const proposedX = e.clientX - startX;
const proposedY = e.clientY - startY;
const limited = limitPanning(proposedX, proposedY);
translateX = limited.x;
translateY = limited.y;
const img = slides.current.querySelector('img');
img.style.transform = `translate(${translateX}px, ${translateY}px) scale(${currentScale})`;
hasPanned = true;
}
});
window.addEventListener('mouseup', function() {
if (isPanning) {
isPanning = false;
container.style.cursor = isZoomed ? 'zoom-out' : 'zoom-in';
}
});
// Touch panning event listeners
container.addEventListener('touchstart', function(e) {
if (isZoomed) {
isPanning = true;
hasPanned = false;
updateBoundaries();
const touch = e.touches[0];
startX = touch.clientX - translateX;
startY = touch.clientY - translateY;
e.preventDefault();
}
});
container.addEventListener('touchmove', function(e) {
if (isPanning && isZoomed) {
const touch = e.touches[0];
const proposedX = touch.clientX - startX;
const proposedY = touch.clientY - startY;
const limited = limitPanning(proposedX, proposedY);
translateX = limited.x;
translateY = limited.y;
const img = slides.current.querySelector('img');
img.style.transform = `translate(${translateX}px, ${translateY}px) scale(${currentScale})`;
hasPanned = true;
e.preventDefault();
}
});
container.addEventListener('touchend', function(e) {
if (isPanning) {
isPanning = false;
}
});