CODEWITHSUNDEEP
javascriptkeyboardkeyboard-shortcuts
user1682315
user1682315

Reputation: 21

Keyboard freezing in web application using javascript

How to freeze keyboard in a web application? i had tried freezing shortcuts,but it is only showing alert,which is defined in the freezing function. But the freeze operation is not working

function disableCtrlKeyCombination(e)
{
    //list all CTRL + key combinations you want to disable
    var forbiddenKeys = new Array('a', 'n', 'c', 'x', 'v', 'j');
    var key;
    var isCtrl;

    if(window.event)
    {
            key = window.event.keyCode;     //IE
            if(window.event.ctrlKey)
                    isCtrl = true;
            else
                    isCtrl = false;
    }

    else
    {
            key = e.which;     //firefox
            if(e.ctrlKey)
                    isCtrl = true;
            else
                    isCtrl = false;
    }

    //if ctrl is pressed check if other key is in forbidenKeys array
    if(isCtrl)
    {
        for(i = 0 ; i < forbiddenKeys.length ; i++)
            {

                    //case-insensitive comparation
                    if(forbiddenKeys[i].toLowerCase() == String.fromCharCode(key).toLowerCase())
                    {
                             alert('Key combination CTRL + '
                                    +String.fromCharCode(key)
                                    +' has been disabled.'); 
                            return false;
                    }
            }
    }       
    return true;

}

Upvotes: 1

Views: 457

Answers (1)

japrescott
japrescott

Reputation: 5015

cancel the keydown event to prevent commands from going through

document.addEventListener("keydown", function(e){e.preventDefault();return false;}, false);

Upvotes: 1

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