Resize handle

src/index.css

@@ -8,6 +8,7 @@
     overflow: hidden;
     margin-bottom: 10px;
     padding-bottom: 0;
+    position: relative;
 
     &-picture {
       max-width: 100%;
@@ -42,6 +43,30 @@
         box-sizing: border-box;
       }
     }
+
+    &-resize-handle {
+      position: absolute;
+      top: 50%;
+      right: 4px;
+      width: 14px;
+      height: 120px;
+      max-height: calc(100% - 8px);
+      background: rgba(0, 0, 0, 0.35);
+      border: 2px solid rgba(255, 255, 255, 0.95);
+      border-radius: 12px;
+      cursor: ew-resize;
+      transform: translateY(-50%);
+      opacity: 0;
+      transition: opacity 0.15s ease, background 0.15s ease;
+    }
+
+    &:hover &-resize-handle {
+      opacity: 1;
+    }
+
+    &-resize-handle:hover {
+      background: rgba(0, 0, 0, 0.5);
+    }
   }
 
   &__caption {
@@ -175,4 +200,4 @@
   100% {
     transform: rotate(360deg);
   }
-}
+}

src/index.ts

@@ -140,6 +140,7 @@ export default class ImageTool implements BlockTool {
      */
     this._data = {
       caption: '',
+      width: undefined,
       withBorder: false,
       withBackground: false,
       stretched: false,
@@ -223,6 +224,7 @@ export default class ImageTool implements BlockTool {
     const caption = this.ui.nodes.caption;
 
     this._data.caption = caption.innerHTML;
+    this._data.width = this.ui.getWidth();
 
     return this.data;
   }
@@ -394,7 +396,9 @@ export default class ImageTool implements BlockTool {
     this.image = data.file;
 
     this._data.caption = data.caption || '';
+    this._data.width = typeof data.width === 'number' ? data.width : undefined;
     this.ui.fillCaption(this._data.caption);
+    this.ui.applyWidth(this._data.width);
 
     ImageTool.tunes.forEach(({ name: tune }) => {
       const value = typeof data[tune as keyof ImageToolData] !== 'undefined' ? data[tune as keyof ImageToolData] === true || data[tune as keyof ImageToolData] === 'true' : false;

src/types/types.ts

@@ -72,6 +72,10 @@ export type ImageToolData<Actions = {}, AdditionalFileData = {}> = {
    * Caption for the image.
    */
   caption: string;
+  /**
+   * Optional width (in pixels) applied to the image container.
+   */
+  width?: number;
 
   /**
    * Flag indicating whether the image has a border.

src/ui.ts

@@ -56,6 +56,11 @@ interface Nodes {
    * Caption element for the image.
    */
   caption: HTMLElement;
+
+  /**
+   * Resize handle element.
+   */
+  resizeHandle?: HTMLElement;
 }
 
 /**
@@ -112,6 +117,11 @@ export default class Ui {
    */
   private readOnly: boolean;
 
+  /**
+   * Tracked width in pixels.
+   */
+  private currentWidth?: number;
+
   /**
    * @param ui - image tool Ui module
    * @param ui.api - Editor.js API
@@ -244,11 +254,73 @@ export default class Ui {
       if (this.nodes.imagePreloader !== undefined) {
         this.nodes.imagePreloader.style.backgroundImage = '';
       }
+      this.applyWidth(this.currentWidth);
+      this.ensureResizeHandle();
     });
 
     this.nodes.imageContainer.appendChild(this.nodes.imageEl);
   }
 
+  /**
+   * Apply a specific width (px) to the image container.
+   */
+  public applyWidth(width?: number): void {
+    const MIN = 40;
+    const parentWidth = this.nodes.wrapper.parentElement?.getBoundingClientRect()?.width;
+    const max = parentWidth && Number.isFinite(parentWidth) ? Math.max(MIN, parentWidth) : undefined;
+    let next = width;
+    if (typeof next === 'number' && next > 0) {
+      if (max) next = Math.min(next, max);
+      next = Math.max(MIN, next);
+      this.currentWidth = next;
+      this.nodes.imageContainer.style.width = `${next}px`;
+    } else {
+      this.currentWidth = undefined;
+      this.nodes.imageContainer.style.width = '';
+    }
+  }
+
+  /**
+   * Returns current width if set.
+   */
+  public getWidth(): number | undefined {
+    if (typeof this.currentWidth === 'number') return this.currentWidth;
+    const inline = parseFloat(this.nodes.imageContainer.style.width);
+    return Number.isFinite(inline) ? inline : undefined;
+  }
+
+  /**
+   * Ensure resize handle exists and is wired.
+   */
+  private ensureResizeHandle(): void {
+    if (this.readOnly || this.nodes.resizeHandle) return;
+    const handle = make('div', this.CSS.resizeHandle);
+    let startX = 0;
+    let startWidth = 0;
+
+    const onMove = (event: MouseEvent) => {
+      const delta = event.clientX - startX;
+      const next = startWidth + delta;
+      this.applyWidth(next);
+    };
+
+    const onUp = () => {
+      document.removeEventListener('mousemove', onMove);
+      document.removeEventListener('mouseup', onUp);
+    };
+
+    handle.addEventListener('mousedown', (event: MouseEvent) => {
+      event.preventDefault();
+      startX = event.clientX;
+      startWidth = this.nodes.imageContainer.getBoundingClientRect().width;
+      document.addEventListener('mousemove', onMove);
+      document.addEventListener('mouseup', onUp);
+    });
+
+    this.nodes.imageContainer.appendChild(handle);
+    this.nodes.resizeHandle = handle;
+  }
+
   /**
    * Shows caption input
    * @param text - caption content text
@@ -291,6 +363,7 @@ export default class Ui {
       imagePreloader: 'image-tool__image-preloader',
       imageEl: 'image-tool__image-picture',
       caption: 'image-tool__caption',
+      resizeHandle: 'image-tool__image-resize-handle',
     };
   };