Question

i would like to know if it is possible to know on which side of the slider the thumb is moving. I have to implement a zoom function based on a slider and i can zoom in, but not zoom out.

if (!zoomSlider.getValueIsAdjusting()) {
            double minY = model.getMinY();
            double maxY = model.getMaxY();

            double distanceY = maxY - minY;

            double posY = minY + distanceY / 2.0;

    if(?) {
            distanceY /= zoomSlider.getValue();
    } else {
    distanceY *= zoomSlider.getValue();
    }

            minY = posY - distanceY / 2.0;
            maxY = posY + distanceY / 2.0;

            changeMaxY(maxY);
    changeMinY(minY);
        }

Thank you.

Answer 1

I want to multiply by 1, 2, 3, or 4 when i go right and divide by 1, 2, 3, or 4 when i move left.

Keep track of the “previous” slider value so you can compare it to the “current” slider value. When the value increases your multiply, when it decreases you divide.