支持图片缩放拖拽

server/public/js/chat.js

@@ -104,30 +104,19 @@ function onImageClick(e) {
   e.stopPropagation();
   const overlay = document.createElement('div');
   overlay.className = 'fullscreen-overlay';
-  overlay.innerHTML = '<img src="' + e.target.src + '" alt="">';
-  overlay.addEventListener('click', () => overlay.remove());
+  overlay.innerHTML = '<img src="' + e.target.src + '" alt="" style="transition: transform 0.1s; transform-origin: 0 0;">';
+  overlay.addEventListener('click', function(ev) { if (ev.target === overlay) overlay.remove(); });
   document.body.appendChild(overlay);
+  initPinchZoom(overlay.querySelector('img'));
 }
 
 function onImgThumbDblClick(img) {
   const overlay = document.createElement('div');
   overlay.className = 'fullscreen-overlay';
-  overlay.innerHTML = '<img src="' + img.src + '" style="max-width:100%;max-height:100%;object-fit:contain" alt="" id="fs-img">';
-  overlay.addEventListener('click', () => overlay.remove());
+  overlay.innerHTML = '<img src="' + img.src + '" style="max-width:100%;max-height:100%;object-fit:contain;transition: transform 0.1s; transform-origin: 0 0;" alt="">';
+  overlay.addEventListener('click', function(ev) { if (ev.target === overlay) overlay.remove(); });
   document.body.appendChild(overlay);
-  var fsImg = overlay.querySelector('#fs-img');
-  var pressTimer;
-  fsImg.addEventListener('touchstart', function() {
-    pressTimer = setTimeout(function() {
-      var a = document.createElement('a');
-      a.href = fsImg.src;
-      a.download = fsImg.src.split('/').pop().split('?')[0] || 'image.jpg';
-      a.click();
-      clearTimeout(pressTimer);
-    }, 800);
-  });
-  fsImg.addEventListener('touchend', function() { clearTimeout(pressTimer); });
-  fsImg.addEventListener('touchmove', function() { clearTimeout(pressTimer); });
+  initPinchZoom(overlay.querySelector('img'));
 }
 
 function onBubbleClick(e) {
@@ -176,7 +165,61 @@ function insertTempBubble() {
 function clearTempBubble() {
   if (Store.tempBubbleTimer) { clearTimeout(Store.tempBubbleTimer); Store.tempBubbleTimer = null; }
   if (Store.pollTimer) { clearInterval(Store.pollTimer); Store.pollTimer = null; }
-  Store.messageCache = Store.messageCache.filter(m => !m.isTemp);
-  const tempEls = messagesContainer.querySelectorAll('[data-msg-id^="temp_"]');
-  tempEls.forEach(el => el.remove());
+  Store.messageCache = Store.messageCache.filter(function(m) { return !m.isTemp; });
+  var tempEls = messagesContainer.querySelectorAll('[data-msg-id^="temp_"]');
+  tempEls.forEach(function(el) { el.remove(); });
+}
+
+// 双指缩放 + 拖拽
+function initPinchZoom(img) {
+  var scale = 1, startDist = 0, startScale = 1;
+  var translateX = 0, translateY = 0;
+  var startX = 0, startY = 0, startTX = 0, startTY = 0;
+  var dragging = false;
+
+  function update() {
+    img.style.transform = 'translate(' + translateX + 'px,' + translateY + 'px) scale(' + scale + ')';
+  }
+
+  img.addEventListener('touchstart', function(e) {
+    if (e.touches.length === 2) {
+      dragging = false;
+      startDist = Math.hypot(e.touches[0].clientX - e.touches[1].clientX, e.touches[0].clientY - e.touches[1].clientY);
+      startScale = scale;
+      startTX = translateX;
+      startTY = translateY;
+      var cx = (e.touches[0].clientX + e.touches[1].clientX) / 2;
+      var cy = (e.touches[0].clientY + e.touches[1].clientY) / 2;
+      startX = cx; startY = cy;
+    } else if (e.touches.length === 1 && scale > 1) {
+      dragging = true;
+      startX = e.touches[0].clientX;
+      startY = e.touches[0].clientY;
+      startTX = translateX;
+      startTY = translateY;
+    }
+  });
+
+  img.addEventListener('touchmove', function(e) {
+    if (e.touches.length === 2) {
+      e.preventDefault();
+      var dist = Math.hypot(e.touches[0].clientX - e.touches[1].clientX, e.touches[0].clientY - e.touches[1].clientY);
+      scale = Math.max(0.5, Math.min(5, startScale * (dist / startDist)));
+      var cx = (e.touches[0].clientX + e.touches[1].clientX) / 2;
+      var cy = (e.touches[0].clientY + e.touches[1].clientY) / 2;
+      translateX = startTX + (cx - startX);
+      translateY = startTY + (cy - startY);
+      update();
+    } else if (e.touches.length === 1 && dragging) {
+      translateX = startTX + (e.touches[0].clientX - startX);
+      translateY = startTY + (e.touches[0].clientY - startY);
+      update();
+    }
+  }, { passive: false });
+
+  img.addEventListener('touchend', function() {
+    dragging = false;
+    if (scale < 0.6) { scale = 0.5; translateX = 0; translateY = 0; update(); }
+    if (scale <= 1) { translateX = 0; translateY = 0; update(); }
+  });
 }