Add resize-handler extension

extensions-builtin/resize-handle/javascript/resize-handle.js

+onUiLoaded(async() => {
+    const GRADIO_MIN_WIDTH = 320;
+    const GRID_TEMPLATE_COLUMNS = '1fr 16px 1fr';
+    const PAD = 16;
+    const DEBOUNCE_TIME = 100;
+
+    const R = {
+        tracking: false,
+        parent: null,
+        parentWidth: null,
+        leftCol: null,
+        leftColStartWidth: null,
+        screenX: null,
+    };
+
+    let resizeTimer;
+
+    const leftCols = [
+        gradioApp().querySelector('#txt2img_settings'),
+        gradioApp().querySelector('#img2img_settings'),
+    ];
+
+    function setLeftColGridTemplate(el, width) {
+        el.style.gridTemplateColumns = `${width}px 16px 1fr`;
+    }
+
+    function displayResizeHandle(parent) {
+        if (window.innerWidth < GRADIO_MIN_WIDTH * 2 + PAD * 4) {
+            parent.style.display = 'flex';
+            if (R.handle != null) {
+                R.handle.style.opacity = '0';
+            }
+            return false;
+        } else {
+            parent.style.display = 'grid';
+            if (R.handle != null) {
+                R.handle.style.opacity = '100';
+            }
+            return true;
+        }
+    }
+
+    function setup() {
+        for (const leftCol of leftCols) {
+            const parent = leftCol.parentElement;
+            const rightCol = parent.lastElementChild;
+
+            if (!displayResizeHandle(parent)) {
+                return;
+            }
+
+            parent.style.display = 'grid';
+            parent.style.gap = '0';
+            parent.style.gridTemplateColumns = GRID_TEMPLATE_COLUMNS;
+
+            const resizeHandle = document.createElement('div');
+            resizeHandle.classList.add('resize-handle');
+            parent.insertBefore(resizeHandle, rightCol);
+
+            resizeHandle.addEventListener('mousedown', (evt) => {
+                R.tracking = true;
+                R.parent = parent;
+                R.parentWidth = parent.offsetWidth;
+                R.handle = resizeHandle;
+                R.leftCol = leftCol;
+                R.leftColStartWidth = leftCol.offsetWidth;
+                R.screenX = evt.screenX;
+            });
+        }
+    }
+
+    window.addEventListener('mousemove', (evt) => {
+        if (R.tracking) {
+            const delta = R.screenX - evt.screenX;
+            const leftColWidth = Math.max(Math.min(R.leftColStartWidth - delta, R.parent.offsetWidth - GRADIO_MIN_WIDTH - PAD), GRADIO_MIN_WIDTH);
+            setLeftColGridTemplate(R.parent, leftColWidth);
+        }
+    });
+
+    window.addEventListener('mouseup', () => R.tracking = false);
+
+    window.addEventListener('resize', () => {
+        clearTimeout(resizeTimer);
+
+        resizeTimer = setTimeout(() => {
+            for (const leftCol of leftCols) {
+                const parent = leftCol.parentElement;
+
+                if (displayResizeHandle(parent) && parent.style.gridTemplateColumns != GRID_TEMPLATE_COLUMNS) {
+                    const oldParentWidth = R.parentWidth;
+                    const newParentWidth = parent.offsetWidth;
+                    const widthL = parseInt(parent.style.gridTemplateColumns.split(' ')[0]);
+
+                    const ratio = newParentWidth / oldParentWidth;
+
+                    const newWidthL = Math.max(Math.floor(ratio * widthL), GRADIO_MIN_WIDTH);
+                    setLeftColGridTemplate(parent, newWidthL);
+
+                    R.parentWidth = newParentWidth;
+                }
+            }
+        }, DEBOUNCE_TIME);
+    });
+
+    setup();
+});

extensions-builtin/resize-handle/style.css

+.resize-handle{
+	cursor: col-resize;
+	grid-column: 2 / 3;
+	min-width: 8px !important;
+	max-width: 8px !important;
+	height: 100%;
+	border-left: 1px dashed var(--border-color-primary);
+	user-select: none;
+	margin-left: 8px;
+}
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