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positiongroupingkonvajsreact-konvakonvajs-reactjs

Konvajs: How to change position of group of texts


I'm using Konvajs, I have group of texts, and I want don't allow drag group outside of the canvas, I'm tried solved that using dragBoundFunc, but that don't help me, now I just try change group position during dragmove, but setPosition, setAbsloutePosition, nothing allow me to change group position

stage.on('dragmove', (e) => stageOnDragMove(e, layer));
const stageOnDragMove = (e: Konva.KonvaEventObject<any>, layer: Konva.Layer) => {

    const selectionGroup = layer.findOne('#selection-group');
    const transformer = layer.findOne<Konva.Transformer>('Transformer');

    if (selectionGroup?.hasName('text-group')) {
        const pos = selectionGroup.getClientRect({});

        if (pos.x <= 0 || pos.y <= 0) {
            selectionGroup.setAbsolutePosition({
                x: 0,
                y: 0
            });
            layer.draw();
        }
    }

    transformer.attachTo(selectionGroup);
};

Solution

  • You can use this function to limit drag&drop and resize feature to limit its boundaries:

    shape.on('dragmove transform', () => {
      const box = shape.getClientRect();
      const absPos = shape.getAbsolutePosition();
      const offsetX = box.x - absPos.x;
      const offsetY = box.y - absPos.y;
    
      const newAbsPos = {...absPos}
      if (box.x < 0) {
        newAbsPos.x = -offsetX;
      }
      if (box.y < 0) {
        newAbsPos.y = -offsetY;
      }
      if (box.x + box.width > stage.width()) {
        newAbsPos.x = stage.width() - box.width - offsetX;
      }
      if (box.y + box.height > stage.height()) {
        newAbsPos.y = stage.height() - box.height - offsetY;
      }
      shape.setAbsolutePosition(newAbsPos)
    })
    

    Demo: https://jsbin.com/rofupicupu/edit?html,js,output