How to change Mouse event and Keyboard Input In Dygraphs

Question

How to change Mouse event and Keyboard Input In Dygraphs.

I want to change the Range selector or X Axis movement to keyboard and mouse combinations

Range Selector [Drag] --> Shift + Drag

X Axis movement [ Shift + Drag ] --> Ctrl + Drag

BR

Answer 1

To achieve custom mouse and keyboard interactions in Dygraphs for range selection and X-axis movement, you can listen for mouse and keyboard events and then handle them accordingly to change the behavior.

// Get a reference to your Dygraph instance
const dygraph = new Dygraph(...);

document.addEventListener('mousedown', handleMouseDown);
document.addEventListener('mouseup', handleMouseUp);
document.addEventListener('mousemove', handleMouseMove);
document.addEventListener('keydown', handleKeyDown);
document.addEventListener('keyup', handleKeyUp);

let isMouseDown = false;
let isShiftKeyDown = false;
let isCtrlKeyDown = false;
let startX = 0;

// Function to handle mouse down event
function handleMouseDown(event) {
  if (event.shiftKey) {
    isMouseDown = true;
    startX = event.clientX;
  }
}

// Function to handle mouse up event
function handleMouseUp(event) {
  isMouseDown = false;
}

// Function to handle mouse move event
function handleMouseMove(event) {
  if (isMouseDown && isShiftKeyDown) {
    // Handle range selection
    const endX = event.clientX;
    const selectedRange = [startX, endX];
    // Do something with the selected range
  }
}

// Function to handle key down event
function handleKeyDown(event) {
  if (event.key === 'Shift') {
    isShiftKeyDown = true;
  } else if (event.key === 'Control') {
    isCtrlKeyDown = true;
  }
}

// Function to handle key up event
function handleKeyUp(event) {
  if (event.key === 'Shift') {
    isShiftKeyDown = false;
  } else if (event.key === 'Control') {
    isCtrlKeyDown = false;
  }
}

You can modify the handleMouseMove function to handle X-axis movement when the Ctrl key is pressed, similar to how range selection is handled with the Shift key. Additionally, you can adjust the logic to suit your specific requirements.

Ref: https://dygraphs.com/options.html