Wheel Zoom Example

Wheel zoom allows users to zoom in and out by scrolling with their mouse wheel or using pinch gestures on touch devices. This is the most versatile zoom mode, supporting programmatic controls, rotation, and image cropping.

Features

Scroll or pinch to zoom in/out
Programmatic zoom controls (zoom in/out buttons)
Image rotation at 90-degree increments
Image cropping based on current zoom state
Real-time zoom percentage display
State management and subscriptions

Vanilla JavaScript

HTML
JavaScript

<div id="image-wheel-container" class="h-[300px] w-[200px]">
  <img src="/sample.avif" alt="Zoomable image" />
</div>

<p id="currentZoom">Current zoom: 100%</p>

<div>
  <button id="zoomInBtn">Zoom in</button>
  <button id="zoomOutBtn">Zoom out</button>
  <button id="cropImgBtn">Crop image</button>
  <button id="rotateImgBtn">Rotate</button>
</div>

<img id="cropImg" hidden alt="Cropped" />

import { createZoomImageWheel, cropImage } from "@zoom-image/core";

const container = document.getElementById("image-wheel-container");
const result = createZoomImageWheel(container);

const controller = new AbortController();
const cropImg = document.getElementById("cropImg");
const currentZoom = document.getElementById("currentZoom");
const zoomInBtn = document.getElementById("zoomInBtn");
const zoomOutBtn = document.getElementById("zoomOutBtn");
const cropImgBtn = document.getElementById("cropImgBtn");
const rotateImgBtn = document.getElementById("rotateImgBtn");

// Subscribe to zoom state changes
result.subscribe(({ state }) => {
  currentZoom.textContent = `Current zoom: ${Math.round(state.currentZoom * 100)}%`;
});

// Zoom in button
zoomInBtn.addEventListener(
  "click",
  () => {
    result.setState({
      currentZoom: result.getState().currentZoom + 0.5,
    });
  },
  { signal: controller.signal }
);

// Zoom out button
zoomOutBtn.addEventListener(
  "click",
  () => {
    result.setState({
      currentZoom: result.getState().currentZoom - 0.5,
    });
  },
  { signal: controller.signal }
);

// Crop image
async function handleCropImage() {
  const currentState = result.getState();
  const croppedImage = await cropImage({
    image: container.querySelector("img"),
    currentZoom: currentState.currentZoom,
    positionX: currentState.currentPositionX,
    positionY: currentState.currentPositionY,
    rotation: currentState.currentRotation,
  });

  cropImg.src = croppedImage;
  cropImg.hidden = false;
}

cropImgBtn.addEventListener("click", handleCropImage, {
  signal: controller.signal,
});

// Rotate image
rotateImgBtn.addEventListener(
  "click",
  () => {
    result.setState({
      currentRotation: result.getState().currentRotation + 90,
    });
  },
  { signal: controller.signal }
);

// Cleanup
function cleanup() {
  result.cleanup();
  controller.abort();
}

React

import { cropImage } from "@zoom-image/core";
import { useZoomImageWheel } from "@zoom-image/react";
import { useEffect, useMemo, useRef, useState } from "react";

function WheelZoomExample() {
  const imageContainerRef = useRef<HTMLDivElement>(null);
  const [croppedImage, setCroppedImage] = useState<string | null>(null);

  const {
    createZoomImage,
    zoomImageState,
    setZoomImageState,
  } = useZoomImageWheel();

  // Initialize zoom on mount
  useEffect(() => {
    if (imageContainerRef.current) {
      createZoomImage(imageContainerRef.current);
    }
  }, [createZoomImage]);

  const croppedImageClasses = useMemo(() => {
    if (zoomImageState.currentRotation % 180 === 90) {
      return "h-[200px] w-[300px]";
    }
    return "h-[300px] w-[200px]";
  }, [zoomImageState.currentRotation]);

  async function handleCropImage() {
    const cropped = await cropImage({
      currentZoom: zoomImageState.currentZoom,
      image: imageContainerRef.current?.querySelector("img") as HTMLImageElement,
      positionX: zoomImageState.currentPositionX,
      positionY: zoomImageState.currentPositionY,
      rotation: zoomImageState.currentRotation,
    });
    setCroppedImage(cropped);
  }

  function zoomIn() {
    setZoomImageState({
      currentZoom: zoomImageState.currentZoom + 0.5,
    });
  }

  function zoomOut() {
    setZoomImageState({
      currentZoom: zoomImageState.currentZoom - 0.5,
    });
  }

  function rotate() {
    setZoomImageState({
      currentRotation: zoomImageState.currentRotation + 90,
    });
  }

  return (
    <div>
      <p>Current zoom: {Math.round(zoomImageState.currentZoom * 100)}%</p>
      <p>Scroll inside the image to zoom in/out</p>

      <div className="flex items-center gap-4">
        <div className="h-[300px] w-[300px] bg-black grid place-content-center">
          <div
            ref={imageContainerRef}
            className="h-[300px] w-[200px] cursor-crosshair"
          >
            <img
              className="h-full w-full"
              alt="Zoomable"
              src="/sample.avif"
            />
          </div>
        </div>
        {croppedImage && (
          <img
            src={croppedImage}
            className={croppedImageClasses}
            alt="Cropped"
          />
        )}
      </div>

      <div className="flex space-x-2 mt-4">
        <button onClick={zoomIn}>Zoom in</button>
        <button onClick={zoomOut}>Zoom out</button>
        <button onClick={handleCropImage}>Crop image</button>
        <button onClick={rotate}>Rotate</button>
      </div>
    </div>
  );
}

export default WheelZoomExample;

Vue

<script setup lang="ts">
import { cropImage } from "@zoom-image/core";
import { useZoomImageWheel } from "@zoom-image/vue";
import { computed, onMounted, ref } from "vue";

const imageContainerRef = ref<HTMLDivElement>();
const croppedImage = ref<string>();

const {
  createZoomImage,
  zoomImageState,
  setZoomImageState,
} = useZoomImageWheel();

const croppedImageClasses = computed(() => {
  if (zoomImageState.currentRotation % 180 === 90) {
    return "h-[200px] w-[300px]";
  }
  return "h-[300px] w-[200px]";
});

const handleCropImage = async () => {
  croppedImage.value = await cropImage({
    currentZoom: zoomImageState.currentZoom,
    image: (imageContainerRef.value as HTMLDivElement).querySelector("img") as HTMLImageElement,
    positionX: zoomImageState.currentPositionX,
    positionY: zoomImageState.currentPositionY,
    rotation: zoomImageState.currentRotation,
  });
};

const zoomIn = () => {
  setZoomImageState({
    currentZoom: zoomImageState.currentZoom + 0.5,
  });
};

const zoomOut = () => {
  setZoomImageState({
    currentZoom: zoomImageState.currentZoom - 0.5,
  });
};

const rotate = () => {
  setZoomImageState({
    currentRotation: zoomImageState.currentRotation + 90,
  });

  if (croppedImage.value) {
    handleCropImage();
  }
};

onMounted(() => {
  createZoomImage(imageContainerRef.value as HTMLDivElement);
});
</script>

<template>
  <div>
    <p>Scroll / Pinch inside the image to see zoom in-out effect</p>
    <p>Current zoom: {{ `${Math.round(zoomImageState.currentZoom * 100)}%` }}</p>

    <div class="flex items-center gap-4">
      <div class="mt-1 grid h-[300px] w-[300px] place-content-center bg-black">
        <div ref="imageContainerRef" class="h-[300px] w-[200px] cursor-crosshair">
          <img class="h-full w-full" alt="Large Pic" src="/sample.avif" />
        </div>
      </div>
      <img
        v-if="croppedImage"
        :src="croppedImage"
        :class="croppedImageClasses"
        alt="Cropped"
      />
    </div>

    <div class="flex space-x-2 mt-4">
      <button @click="zoomIn">Zoom in</button>
      <button @click="zoomOut">Zoom out</button>
      <button @click="handleCropImage">Crop image</button>
      <button @click="rotate">Rotate</button>
    </div>
  </div>
</template>

Svelte

<script lang="ts">
  import { cropImage, type ZoomImageWheelState } from "@zoom-image/core";
  import { useZoomImageWheel } from "@zoom-image/svelte";
  import { onMount } from "svelte";

  let imageContainer: HTMLDivElement;
  let croppedImage: string = "";

  let {
    createZoomImage,
    zoomImageState,
    setZoomImageState,
  } = useZoomImageWheel();

  let zoomImageStateValue: ZoomImageWheelState;

  zoomImageState.subscribe((value) => {
    zoomImageStateValue = value;
  });

  $: croppedImageClasses =
    zoomImageStateValue.currentRotation % 180 === 90
      ? "h-[200px] w-[300px]"
      : "h-[300px] w-[200px]";

  async function handleCropImage() {
    croppedImage = await cropImage({
      currentZoom: zoomImageStateValue.currentZoom,
      image: imageContainer.querySelector("img") as HTMLImageElement,
      positionX: zoomImageStateValue.currentPositionX,
      positionY: zoomImageStateValue.currentPositionY,
      rotation: zoomImageStateValue.currentRotation,
    });
  }

  function rotate() {
    setZoomImageState({
      currentRotation: zoomImageStateValue.currentRotation + 90,
    });

    if (croppedImage) {
      handleCropImage();
    }
  }

  onMount(() => createZoomImage(imageContainer));
</script>

<div>
  <p>Current zoom: {`${Math.round(zoomImageStateValue.currentZoom * 100)}%`}</p>
  <p>Scroll inside the image to see zoom in-out effect</p>

  <div class="flex items-center gap-4">
    <div class="mt-1 grid h-[300px] w-[300px] place-content-center bg-black">
      <div bind:this={imageContainer} class="h-[300px] w-[200px] cursor-crosshair">
        <img class="h-full w-full" alt="Large Pic" src="/sample.avif" />
      </div>
    </div>

    {#if croppedImage !== ""}
      <img src={croppedImage} class={croppedImageClasses} alt="Cropped" />
    {/if}
  </div>

  <div class="flex space-x-2 mt-4">
    <button
      on:click={() => {
        setZoomImageState({
          currentZoom: zoomImageStateValue.currentZoom + 0.5,
        });
      }}
    >
      Zoom in
    </button>
    <button
      on:click={() => {
        setZoomImageState({
          currentZoom: zoomImageStateValue.currentZoom - 0.5,
        });
      }}
    >
      Zoom out
    </button>
    <button on:click={handleCropImage}>Crop image</button>
    <button on:click={rotate}>Rotate</button>
  </div>
</div>

Angular

import { AfterViewInit, Component, ElementRef, ViewChild } from "@angular/core";
import { CommonModule } from "@angular/common";
import { ZoomImageWheelService } from "@zoom-image/angular";
import { ZoomImageWheelState, cropImage } from "@zoom-image/core";

@Component({
  selector: "app-wheel-zoom",
  templateUrl: "./wheel-zoom.component.html",
  providers: [ZoomImageWheelService],
  imports: [CommonModule],
})
export class WheelZoomComponent implements AfterViewInit {
  @ViewChild("imageContainer") imageContainerRef?: ElementRef<HTMLDivElement>;

  croppedImage: string = "";
  zoomImageState: ZoomImageWheelState = this.zoomService.zoomImageState;

  constructor(private zoomService: ZoomImageWheelService) {}

  ngAfterViewInit(): void {
    if (this.imageContainerRef) {
      this.zoomService.createZoomImage(
        this.imageContainerRef.nativeElement
      );
      this.zoomService.zoomImageState$.subscribe((state) => {
        this.zoomImageState = state;
      });
    }
  }

  getCurrentZoom() {
    return `${Math.round(this.zoomImageState.currentZoom * 100)}%`;
  }

  zoomIn() {
    this.zoomService.setZoomImageState({
      currentZoom: this.zoomImageState.currentZoom + 0.5,
    });
  }

  zoomOut() {
    this.zoomService.setZoomImageState({
      currentZoom: this.zoomImageState.currentZoom - 0.5,
    });
  }

  rotate() {
    const currentRotation = this.zoomImageState.currentRotation + 90;
    this.zoomService.setZoomImageState({ currentRotation });

    if (this.croppedImage) {
      this.handleCropImage(currentRotation);
    }
  }

  async handleCropImage(currentRotation = this.zoomImageState.currentRotation) {
    this.croppedImage = await cropImage({
      currentZoom: this.zoomImageState.currentZoom,
      image: (this.imageContainerRef?.nativeElement as HTMLDivElement)
        .querySelector("img") as HTMLImageElement,
      positionX: this.zoomImageState.currentPositionX,
      positionY: this.zoomImageState.currentPositionY,
      rotation: currentRotation,
    });
  }

  getCroppedImageClasses() {
    if (this.zoomImageState.currentRotation % 180 === 90) {
      return "h-[200px] w-[300px]";
    }
    return "h-[300px] w-[200px]";
  }
}

Key Configuration Options

maxZoom

Sets the maximum zoom level (default: 4).

const result = createZoomImageWheel(container, {
  maxZoom: 5,
});

wheelZoomRatio

Controls zoom increment per scroll event (default: 0.1).

const result = createZoomImageWheel(container, {
  wheelZoomRatio: 0.2, // Faster zooming
});

zoomImageSource

Specifies a high-resolution image for zoomed view.

const result = createZoomImageWheel(container, {
  zoomImageSource: "/high-res-image.jpg",
});

Common Use Cases

Image Editor

Provide users with zoom controls, rotation, and cropping capabilities for image editing applications.

Product Photography

Allow customers to examine product details with smooth zoom interactions on both desktop and mobile devices.

Medical Imaging

Enable healthcare professionals to zoom and pan through diagnostic images with precise control.

Map Viewers

Implement interactive map exploration with wheel zoom and programmatic navigation controls.

Get Started

Core Concepts

Guides

Framework Adapters

Examples

Features

Vanilla JavaScript

React

Vue

Svelte

Angular

Key Configuration Options

maxZoom

wheelZoomRatio

zoomImageSource

Common Use Cases

Image Editor

Product Photography

Medical Imaging

Map Viewers

Build docs developers (and LLMs) love

Get Started

Core Concepts

Guides

Framework Adapters

Examples

​Features

​Vanilla JavaScript

​React

​Vue

​Svelte

​Angular

​Key Configuration Options

​maxZoom

​wheelZoomRatio

​zoomImageSource

​Common Use Cases

​Image Editor

​Product Photography

​Medical Imaging

​Map Viewers

​Related

Build docs developers (and LLMs) love

Features

Vanilla JavaScript

React

Vue

Svelte

Angular

Key Configuration Options

maxZoom

wheelZoomRatio

zoomImageSource

Common Use Cases

Image Editor

Product Photography

Medical Imaging

Map Viewers

Related