You can use JavaScript to implement a custom copy function that is triggered when the user clicks a mouse button. Here is an example code that copies the selected text to the clipboard when the user right-clicks on it:

document.addEventListener('contextmenu', event => {
  event.preventDefault();
  const selection = window.getSelection().toString();
  if (selection) {
    copyToClipboard(selection);
  }
});

function copyToClipboard(text) {
  const el = document.createElement('textarea');
  el.value = text;
  document.body.appendChild(el);
  el.select();
  document.execCommand('copy');
  document.body.removeChild(el);
}

This code adds an event listener to the contextmenu event, which is triggered when the user right-clicks on the web page. The preventDefault() method is called to prevent the default behavior of the event, which is to display the context menu. The window.getSelection() method is called to get the selected text, and the copyToClipboard() function is called to copy the text to the clipboard.

The copyToClipboard() function creates a temporary textarea element, sets its value to the provided text, appends it to the document body, selects the text, calls the document.execCommand('copy') method to copy the selected text to the clipboard, and removes the textarea element from the document body.

Note that this approach only works when the user selects text using the mouse, and not when they use keyboard shortcuts to copy text. Additionally, the document.execCommand() method is not supported in all browsers, so this code may not work in all situations.

It is generally not recommended to disable keyboard shortcuts or modify the default behavior of browser controls, as this can interfere with user accessibility and can also be bypassed using browser extensions or custom user settings. However, if you want to prevent the use of certain keyboard shortcuts (such as Ctrl+C for copy or Ctrl+V for paste), you can use JavaScript to listen for keydown events and prevent the default behavior of the event when certain keys are pressed. Here is an example code that prevents the use of Ctrl+C and Ctrl+V:

document.addEventListener('keydown', event => {
  if (event.ctrlKey && (event.key === 'c' || event.key === 'C' || event.key === 'v' || event.key === 'V')) {
    event.preventDefault();
  }
});

This code adds an event listener to the keydown event, which is triggered when a key is pressed. The ctrlKey property of the event object is used to check if the Ctrl key is being held down, and the key property is used to check if the pressed key is 'c' or 'v'. If these conditions are met, the preventDefault() method is called to prevent the default behavior of the event (which is to copy or paste text).

Again, it is generally not recommended to disable browser controls or keyboard shortcuts, as this can make it difficult for users to navigate and interact with your web page.

You can use JavaScript to prevent the right-click menu from appearing on a web page. Here is an example code:

document.addEventListener('contextmenu', event => event.preventDefault());

This code adds an event listener to the contextmenu event, which is triggered when the user right-clicks on the web page. The preventDefault() method is called to prevent the default behavior of the event, which is to display the context menu.

Note that disabling the right-click menu can interfere with user accessibility and can also be bypassed using browser extensions or by disabling JavaScript. Additionally, disabling right-clicking can make it difficult for users to access certain browser features, such as opening links in a new tab or saving images. Therefore, it is generally not recommended to disable right-clicking on a web page.

You can use CSS to prevent text selection on a web page by using the user-select property. Here is an example CSS code:

body {
  -webkit-user-select: none; /* Safari */
  -moz-user-select: none; /* Firefox */
  -ms-user-select: none; /* Internet Explorer/Edge */
  user-select: none; /* Non-prefixed version */
}

This will prevent users from selecting text on the entire web page. If you want to allow text selection on certain elements, you can selectively enable text selection by overriding the user-select property for those elements:

.allow-select {
  -webkit-user-select: text; /* Safari */
  -moz-user-select: text; /* Firefox */
  -ms-user-select: text; /* Internet Explorer/Edge */
  user-select: text; /* Non-prefixed version */
}

You can apply this class to any HTML element (such as a div or span) that you want to allow text selection on. Note that this approach only prevents user selection through clicking and dragging the mouse. Users can still select text through other means, such as using keyboard shortcuts or the browser's built-in selection tools.