image_edit.js

# add this js file /static/js/image_edit.js

$(document).ready(function(){
    var width = window.innerWidth;
    var height = window.innerHeight;

    function update(activeAnchor) {
        var group = activeAnchor.getParent();

        var topLeft = group.get('.topLeft')[0];
        var topRight = group.get('.topRight')[0];
        var bottomRight = group.get('.bottomRight')[0];
        var bottomLeft = group.get('.bottomLeft')[0];
        var image = group.get('Image')[0];

        var anchorX = activeAnchor.getX();
        var anchorY = activeAnchor.getY();

        // update anchor positions
        switch (activeAnchor.getName()) {
            case 'topLeft':
                topRight.setY(anchorY);
                bottomLeft.setX(anchorX);
                break;
            case 'topRight':
                topLeft.setY(anchorY);
                bottomRight.setX(anchorX);
                break;
            case 'bottomRight':
                bottomLeft.setY(anchorY);
                topRight.setX(anchorX);
                break;
            case 'bottomLeft':
                bottomRight.setY(anchorY);
                topLeft.setX(anchorX);
                break;
        }

        image.position(topLeft.position());

        var width = topRight.getX() - topLeft.getX();
        var height = bottomLeft.getY() - topLeft.getY();
        if(width && height) {
            image.width(width);
            image.height(height);
        }
    }
    function addAnchor(group, x, y, name) {
        var stage = group.getStage();
        var layer = group.getLayer();

        var anchor = new Konva.Circle({
            x: x,
            y: y,
            stroke: '#666',
            fill: '#ddd',
            strokeWidth: 2,
            radius: 8,
            name: name,
            draggable: true,
            dragOnTop: false
        });

        anchor.on('dragmove', function() {
            update(this);
            layer.draw();
        });
        anchor.on('mousedown touchstart', function() {
            group.setDraggable(false);
            this.moveToTop();
        });
        anchor.on('dragend', function() {
            group.setDraggable(true);
            layer.draw();
        });
        // add hover styling
        anchor.on('mouseover', function() {
            var layer = this.getLayer();
            document.body.style.cursor = 'pointer';
            this.setStrokeWidth(4);
            layer.draw();
        });
        anchor.on('mouseout', function() {
            var layer = this.getLayer();
            document.body.style.cursor = 'default';
            this.setStrokeWidth(2);
            layer.draw();
        });

        group.add(anchor);
    }

    var stage = new Konva.Stage({
        container: 'container',
        width: width,
        height: height
    });

    var layer = new Konva.Layer();
    stage.add(layer);

    var imagesSrc = $('img.edit-image');

    imagesSrc.each(function(){

        var x = $(this).offset().top;
        var y = $(this).offset().left;
        var width = $(this).width()
        var height = $(this).height();

        console.log(x, y);

        // darth vader
        var konvaImg = new Konva.Image({
            width: width,
            height: height
        });


        var konvaImgGroup = new Konva.Group({
            x: x,
            y: y,
            draggable: true
        });

        layer.add(konvaImgGroup);
        konvaImgGroup.add(konvaImg);
        addAnchor(konvaImgGroup, x, x, 'topLeft');
        addAnchor(konvaImgGroup, width, x, 'topRight');
        addAnchor(konvaImgGroup, width, height, 'bottomRight');
        addAnchor(konvaImgGroup, x, height, 'bottomLeft');

        var imageObj = new Image();
        imageObj.onload = function() {
            konvaImg.image(imageObj);
            layer.draw();
        };

        imageObj.src = $(this).attr('src');

    });

});