feat: 顶部工具栏新增叠加图片按钮

js/script.js

@@ -2,6 +2,7 @@
 (function() {
     const fileInput = document.getElementById('fileInput');
     const addImageBtn = document.getElementById('addImageBtn');
+    const addOverlayBtn = document.getElementById('addOverlayBtn');
     const saveBtn = document.getElementById('saveBtn');
     const imageContainer = document.getElementById('imageContainer');
     const bgLayer = document.getElementById('bgLayer');
@@ -18,6 +19,12 @@
     const colorPicker = document.getElementById('colorPicker');
     const fontPicker = document.getElementById('fontPicker');
     const fontSizePicker = document.getElementById('fontSizePicker');
+    const overlayLayer = document.getElementById('overlayLayer');
+    const overlayInput = document.createElement('input');
+    overlayInput.type = 'file';
+    overlayInput.accept = 'image/*';
+    overlayInput.hidden = true;
+    document.body.appendChild(overlayInput);
     const guideH = document.getElementById('guideH');
     const guideV = document.getElementById('guideV');
 
@@ -43,6 +50,20 @@
             fileInput.click();
         });
 
+        // 层叠图按钮
+        addOverlayBtn.addEventListener('click', () => {
+            overlayInput.click();
+        });
+
+        // 层叠图文件选择
+        overlayInput.addEventListener('change', (e) => {
+            const file = e.target.files[0];
+            if (file) {
+                loadOverlayImage(file);
+            }
+            overlayInput.value = '';
+        });
+
         // 文件选择
         fileInput.addEventListener('change', (e) => {
             const file = e.target.files[0];
@@ -139,6 +160,276 @@
         reader.readAsDataURL(file);
     }
 
+    // 加载层叠图
+    function loadOverlayImage(file) {
+        const reader = new FileReader();
+        reader.onload = (e) => {
+            const img = new Image();
+            img.onload = () => {
+                createOverlayElement(img);
+            };
+            img.src = e.target.result;
+        };
+        reader.readAsDataURL(file);
+    }
+
+    // 创建层叠图元素
+    function createOverlayElement(img) {
+        const container = imageContainer;
+        const containerWidth = container.clientWidth;
+        const containerHeight = container.clientHeight;
+
+        // 计算初始尺寸（不超过容器1/3）
+        let width = img.naturalWidth;
+        let height = img.naturalHeight;
+        const maxSize = Math.min(containerWidth, containerHeight) / 2;
+
+        if (width > maxSize || height > maxSize) {
+            if (width > height) {
+                height = (height / width) * maxSize;
+                width = maxSize;
+            } else {
+                width = (width / height) * maxSize;
+                height = maxSize;
+            }
+        }
+
+        // 创建层叠图元素
+        const overlayEl = document.createElement('div');
+        overlayEl.className = 'overlay-image';
+        overlayEl.dataset.scale = 1;
+
+        const imgEl = document.createElement('img');
+        imgEl.src = img.src;
+        imgEl.style.width = '100%';
+        imgEl.style.height = '100%';
+        imgEl.style.objectFit = 'contain';
+        overlayEl.appendChild(imgEl);
+
+        // 删除按钮
+        const deleteBtn = document.createElement('button');
+        deleteBtn.className = 'delete-btn';
+        deleteBtn.innerHTML = '×';
+        deleteBtn.addEventListener('click', (e) => {
+            e.stopPropagation();
+            overlayEl.remove();
+        });
+        overlayEl.appendChild(deleteBtn);
+
+        // 居中显示
+        overlayEl.style.left = (containerWidth / 2 - width / 2) + 'px';
+        overlayEl.style.top = (containerHeight / 2 - height / 2) + 'px';
+        overlayEl.style.width = width + 'px';
+        overlayEl.style.height = height + 'px';
+
+        // 初始化拖拽和缩放
+        initOverlayImage(overlayEl);
+
+        overlayLayer.appendChild(overlayEl);
+
+        // 选中新添加的层叠图
+        selectOverlay(overlayEl);
+    }
+
+    // 初始化层叠图交互
+    function initOverlayImage(overlayEl) {
+        let isDragging = false;
+        let isResizing = false;
+        let startX, startY, startLeft, startTop, startWidth, startHeight;
+        let currentScale = 1;
+        const minSize = 30;
+
+        // 点击选中
+        overlayEl.addEventListener('click', (e) => {
+            e.stopPropagation();
+            selectOverlay(overlayEl);
+        });
+
+        // 拖拽移动
+        overlayEl.addEventListener('mousedown', handleDragStart);
+        overlayEl.addEventListener('touchstart', handleDragStart, { passive: false });
+
+        function handleDragStart(e) {
+            if (e.target.classList.contains('delete-btn')) return;
+
+            const isTouch = e.type === 'touchstart';
+            const clientX = isTouch ? e.touches[0].clientX : e.clientX;
+            const clientY = isTouch ? e.touches[0].clientY : e.clientY;
+
+            isDragging = true;
+            startX = clientX;
+            startY = clientY;
+            startLeft = overlayEl.offsetLeft;
+            startTop = overlayEl.offsetTop;
+
+            overlayEl.classList.add('dragging');
+
+            document.addEventListener('mousemove', handleDragMove);
+            document.addEventListener('mouseup', handleDragEnd);
+            document.addEventListener('touchmove', handleDragMove, { passive: false });
+            document.addEventListener('touchend', handleDragEnd);
+
+            e.preventDefault();
+        }
+
+        function handleDragMove(e) {
+            if (!isDragging) return;
+
+            const isTouch = e.type === 'touchmove';
+            const clientX = isTouch ? e.touches[0].clientX : e.clientX;
+            const clientY = isTouch ? e.touches[0].clientY : e.clientY;
+
+            const dx = clientX - startX;
+            const dy = clientY - startY;
+
+            let newLeft = startLeft + dx;
+            let newTop = startTop + dy;
+
+            // 边界限制
+            newLeft = Math.max(-overlayEl.offsetWidth + minSize, Math.min(newLeft, imageContainer.offsetWidth - minSize));
+            newTop = Math.max(-overlayEl.offsetHeight + minSize, Math.min(newTop, imageContainer.offsetHeight - minSize));
+
+            overlayEl.style.left = newLeft + 'px';
+            overlayEl.style.top = newTop + 'px';
+
+            e.preventDefault();
+        }
+
+        function handleDragEnd() {
+            isDragging = false;
+            overlayEl.classList.remove('dragging');
+
+            document.removeEventListener('mousemove', handleDragMove);
+            document.removeEventListener('mouseup', handleDragEnd);
+            document.removeEventListener('touchmove', handleDragMove);
+            document.removeEventListener('touchend', handleDragEnd);
+        }
+
+        // 缩放控制（四角）
+        const corners = ['tl', 'tr', 'bl', 'br'];
+        corners.forEach(corner => {
+            const handle = document.createElement('div');
+            handle.className = 'resize-handle resize-' + corner;
+            handle.style.cssText = `
+                position: absolute;
+                width: 12px;
+                height: 12px;
+                background: #4a90e2;
+                border: 1px solid #fff;
+            `;
+
+            switch(corner) {
+                case 'tl': handle.style.top = '-6px'; handle.style.left = '-6px'; handle.style.cursor = 'nw-resize'; break;
+                case 'tr': handle.style.top = '-6px'; handle.style.right = '-6px'; handle.style.cursor = 'ne-resize'; break;
+                case 'bl': handle.style.bottom = '-6px'; handle.style.left = '-6px'; handle.style.cursor = 'sw-resize'; break;
+                case 'br': handle.style.bottom = '-6px'; handle.style.right = '-6px'; handle.style.cursor = 'se-resize'; break;
+            }
+
+            handle.addEventListener('mousedown', startResize);
+            handle.addEventListener('touchstart', startResize, { passive: false });
+
+            overlayEl.appendChild(handle);
+
+            function startResize(e) {
+                e.stopPropagation();
+                isResizing = true;
+                const isTouch = e.type === 'touchstart';
+                const clientX = isTouch ? e.touches[0].clientX : e.clientX;
+                const clientY = isTouch ? e.touches[0].clientY : e.clientY;
+
+                startX = clientX;
+                startY = clientY;
+                startLeft = overlayEl.offsetLeft;
+                startTop = overlayEl.offsetTop;
+                startWidth = overlayEl.offsetWidth;
+                startHeight = overlayEl.offsetHeight;
+
+                document.addEventListener('mousemove', handleResize);
+                document.addEventListener('mouseup', endResize);
+                document.addEventListener('touchmove', handleResize, { passive: false });
+                document.addEventListener('touchend', endResize);
+
+                e.preventDefault();
+            }
+
+            function handleResize(e) {
+                if (!isResizing) return;
+
+                const isTouch = e.type === 'touchmove';
+                const clientX = isTouch ? e.touches[0].clientX : e.clientX;
+                const clientY = isTouch ? e.touches[0].clientY : e.clientY;
+
+                const dx = clientX - startX;
+                const dy = clientY - startY;
+
+                let newWidth = startWidth;
+                let newHeight = startHeight;
+                let newLeft = startLeft;
+                let newTop = startTop;
+
+                const aspectRatio = startWidth / startHeight;
+
+                // 根据角落调整尺寸
+                if (corner === 'br') {
+                    newWidth = Math.max(minSize, startWidth + dx);
+                    newHeight = newWidth / aspectRatio;
+                } else if (corner === 'bl') {
+                    newWidth = Math.max(minSize, startWidth - dx);
+                    newHeight = newWidth / aspectRatio;
+                    newLeft = startLeft - (newWidth - startWidth);
+                } else if (corner === 'tr') {
+                    newWidth = Math.max(minSize, startWidth + dx);
+                    newHeight = newWidth / aspectRatio;
+                    newTop = startTop - (newHeight - startHeight);
+                } else if (corner === 'tl') {
+                    newWidth = Math.max(minSize, startWidth - dx);
+                    newHeight = newWidth / aspectRatio;
+                    newLeft = startLeft - (newWidth - startWidth);
+                    newTop = startTop - (newHeight - startHeight);
+                }
+
+                overlayEl.style.width = newWidth + 'px';
+                overlayEl.style.height = newHeight + 'px';
+                overlayEl.style.left = newLeft + 'px';
+                overlayEl.style.top = newTop + 'px';
+
+                e.preventDefault();
+            }
+
+            function endResize() {
+                isResizing = false;
+                document.removeEventListener('mousemove', handleResize);
+                document.removeEventListener('mouseup', endResize);
+                document.removeEventListener('touchmove', handleResize);
+                document.removeEventListener('touchend', endResize);
+            }
+        });
+    }
+
+    // 选中层叠图
+    let selectedOverlay = null;
+    function selectOverlay(overlayEl) {
+        if (selectedOverlay) {
+            selectedOverlay.classList.remove('selected');
+        }
+        selectedOverlay = overlayEl;
+        overlayEl.classList.add('selected');
+    }
+
+    // 点击背景取消选中层叠图
+    imageContainer.addEventListener('click', (e) => {
+        if (e.target === imageContainer ||
+            e.target === bgLayer ||
+            e.target === bgImage ||
+            e.target === emptyTip ||
+            e.target.closest('.preview-bg-layer')) {
+            if (selectedOverlay) {
+                selectedOverlay.classList.remove('selected');
+                selectedOverlay = null;
+            }
+        }
+    });
+
     // 计算图片滑动边界
     function calculateImageBounds() {
         if (!currentImage) return;