Neurosis Prevention Mechanism

    react-canvas-draw
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    1.2.1 • Public • Published

    React Canvas Draw

    A simple yet powerful canvas-drawing component for React (Demo)

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    Installation

    Install via NPM:

    npm install react-canvas-draw --save
    

    or YARN:

    yarn add react-canvas-draw
    

    Usage

    import React from "react";
    import ReactDOM from "react-dom";
    import CanvasDraw from "react-canvas-draw";
    
    ReactDOM.render(<CanvasDraw />, document.getElementById("root"));

    For more examples, like saving and loading a drawing ==> look into the /demo/src folder.

    Props

    These are the defaultProps of CanvasDraw. You can pass along any of these props to customize the CanvasDraw component. Examples of how to use the props are also shown in the /demo/src folder.

      static defaultProps = {
        onChange: null
        loadTimeOffset: 5,
        lazyRadius: 30,
        brushRadius: 12,
        brushColor: "#444",
        catenaryColor: "#0a0302",
        gridColor: "rgba(150,150,150,0.17)",
        hideGrid: false,
        canvasWidth: 400,
        canvasHeight: 400,
        disabled: false,
        imgSrc: "",
        saveData: null,
        immediateLoading: false,
        hideInterface: false,
        gridSizeX: 25,
        gridSizeY: 25,
        gridLineWidth: 0.5,
        hideGridX: false,
        hideGridY: false
        enablePanAndZoom: false,
        mouseZoomFactor: 0.01,
        zoomExtents: { min: 0.33, max: 3 },
      };

    Functions

    Useful functions that you can call, e.g. when having a reference to this component:

    • getSaveData() returns the drawing's save-data as a stringified object
    • loadSaveData(saveData: String, immediate: Boolean) loads a previously saved drawing using the saveData string, as well as an optional boolean flag to load it immediately, instead of live-drawing it.
    • getDataURL(fileType, useBgImage, backgroundColour) will export the canvas to a data URL, which can subsequently be used to share or manipulate the image file.
    • clear() clears the canvas completely, including previously erased lines, and resets the view. After a clear, undo() will have no effect.
    • eraseAll() clears the drawn lines but retains their data; calling undo() can restore the erased lines. Note: erased lines are not included in the save data.
    • resetView() resets the canvas' view to defaults. Has no effect if the enablePanAndZoom property is false.
    • undo() removes the latest change to the drawing. This includes everything drawn since the last MouseDown event.

    Local Development

    This repo was kickstarted by nwb's awesome react-component starter.

    You just need to clone it, yarn it & start it!

    Tips

    If you want to save large strings, like the stringified JSON of a drawing, I recommend you use pieroxy/lz-string for compression. It's LZ compression will bring down your long strings to only ~10% of its original size.

    Acknowledgement

    The lazy-brush project as well as its demo app by dulnan have been a heavy influence.

    I borrowed a lot of the logic and actually used lazy-brush during the push to v1 of react-canvas-draw. Without it, react-canvas-draw would most likely still be pre v1 and wouldn't feel as good.

    Contributors

    Thanks goes to these wonderful people (emoji key):


    Martin Beierling-Mutz

    💻 📖 💡 🤔

    Jan Hug

    🤔

    This project follows the all-contributors specification. Contributions of any kind welcome!

    License

    MIT, see LICENSE for details.

    Install

    npm i react-canvas-draw

    DownloadsWeekly Downloads

    10,016

    Version

    1.2.1

    License

    MIT

    Unpacked Size

    472 kB

    Total Files

    17

    Last publish

    Collaborators

    • mbeierling