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Fire function only once if another has already been fired

I have created two functions. To keep it simple lets take for an example the following:
I got functions firing different events for the same objects. You can activate them using your keyboard arrows
$("body").keydown(function(e) {
if (event.which == 39) open_second_layer();
});
$("body").keydown(function(e) {
if (event.which == 37) open_first_layer();
});
As soon as I have fired one function and press the same key again it fires the animation one more time (unnecessarily).
Because of that as soon as the function open_second_layer has been fired, it should not be able to be fired again, until open_first_layer is fired again. The same should be the case the other way round.
I found .bind and .when as possible solutions, but can't figure out how to use them the right way for that case. I appreciate every suggestions or keywords to google.

You can keep a state variable and track when changes are made to it:
var state_changed = (function() {
var current = null;
return function(state) {
if (state == current) {
return false;
}
current = state;
return true;
};
}());
function open_first_layer()
{
if (!state_changed(1)) {
return;
}
// rest of code
}
function open_second_layer()
{
if (!state_changed(2)) {
return;
}
// rest of code
}
$("body").keydown(function(e) {
if (event.which == 39) {
open_second_layer();
} else if (event.which == 37) {
open_first_layer();
}
});

You can use jQuery's one().
In your first click handler, you bind the second one.
In your second click handler, you bind the first one.
sample
<div id=activate-first>first</div>
<div id=activate-second style="display:none;">second</div>
$(document).ready(function () {
function slide_first(){
$('#activate-first').show();
$('#activate-second').hide();
$('#activate-second').one('click', slide_first);
};
function slide_second(){
$('#activate-first').hide();
$('#activate-second').show();
$('#activate-first').one('click', slide_second);
};
$('#activate-first').one('click', slide_second);
$('#activate-second').one('click', slide_first);
});

Put the other function inside slide_first, like:
function slide_first(){
// other code
$('#activate_second').one('click', slide_second);
}
$('#activate_first').one('click', slide_first);
or use an Anonymous function to do the same:
$('#activate_first').one('click', function(){
// slide_first code here
$('#activate_second').one('click', function(){
// slide_second code here
});
});
Maybe your really want:
function recursiveSlider(){
$('#activate_first').one('click', function(){
// slide_first code here
$('#activate_second').one('click', function(){
// slide_second code here
recursiveSlider();
});
});
}
recursiveSlider();

This is a perfect use case for delegation. You have a single click event, and whenever the event happens, you determine what has been clicked, and you take action accordingly:
$(document.body).on("click", function(ev) {
var $targ = $(ev.target);
if ($targ.is('#button_1')) {
// someone clicked #button_1
}
if ($targ.is('.page-2 *')) {
// something inside of .page-2 was clicked!!
}
});
UPDATE: now the OP has included more code, I'm not sure the issue is - there's no need to bind and unbind events...
http://jsfiddle.net/ryanwheale/uh63rzbp/1/
function open_first_layer() {
$('#first_panel').addClass('active');
$('#second_panel').removeClass('active');
}
function open_second_layer() {
$('#first_panel').removeClass('active');
$('#second_panel').addClass('active');
}
// one event === good
$("body").keydown(function(e) {
if (event.which == 39) open_second_layer();
if (event.which == 37) open_first_layer();
});
... or if you're trying to build a slider, I suggest changing your naming convention:
http://jsfiddle.net/ryanwheale/uh63rzbp/2/
var current_layer = 1,
$all_layers = $('[id^="panel_"]'),
total_layers = $all_layers.length;
function move_layer (dir) {
current_layer += dir;
if (current_layer < 1) current_layer = total_layers;
else if (current_layer > total_layers) current_layer = 1;
$all_layers.removeClass('active');
$('#panel_' + current_layer).addClass('active');
}
// one event === good
$("body").keydown(function(e) {
if (event.which == 39) move_layer(1);
if (event.which == 37) move_layer(-1);
});
move_layer(0);

Using shift key and click to go to the next slide

Hei guys, i added these lines of code as javascript on succes of a click box in captivate :
document.onkeydown = function (e) {
if (e.keyCode == 16) {
document.Captivate.cpEISetValue('m_VarHandle.cpCmndGotoSlide', 5);
}
};
It does good what it does but after first atempt even if im on another slide and i press shift key it goes to slide 5 :( Another question is, how to set an mousedown and onkeyup event on same button. What i try to achieve is to jump to next slide if i press shift key and i click on a click box.
EDIT: new code:
document.onmousedown = function (e) {
var currentSlide = document.Captivate.cpEIGetValue('m_VarHandle.cpInfoCurrentSlide');
if(currentSlide == 5 && e.keyCode == 16){
document.Captivate.cpEISetValue('m_VarHandle.cpCmndGotoSlide' , 5);
}
};
As i think it, should fire the function when i click on it, BUUUT , unfortunately it doesnt work... seems like Captivate doesnt recognize onmousedown event :|
RE-EDIT : i figurate out how to make it work. Here's the code :
document.onkeydown = function(e) {
var currentFrame = document.Captivate.cpEIGetValue('m_VarHandle.rdinfoCurrentFrame');
var currentSlide = document.Captivate.cpEIGetValue('m_VarHandle.cpInfoCurrentSlide');
if(currentSlide == 5 && e.keyCode == 16){
document.Captivate.cpEISetValue('m_VarHandle.rdcmndGotoFrameAndResume' , 491);
}
};
document.onkeyup = function(e) {
var currentSlide = document.Captivate.cpEIGetValue('m_VarHandle.cpInfoCurrentSlide');
if(currentSlide == 5){
document.Captivate.cpEISetValue('m_VarHandle.rdcmndGotoFrameAndResume' , 485);
}
};
Now everything's just PERFECT! its exactly what i wanted to do... but it works only on localhost... only when i press F12 in Captivate :( if i try to run exported swf or html from captivate it crush :((( Any ideea ?

var slide = 4;
document.onkeydown = function (e) {
if (e.keyCode == 16) {
slide++;
document.Captivate.cpEISetValue('m_VarHandle.cpCmndGotoSlide', slide);
}
};
Bassically you want to increment the position (second argument of cpEISetValue), in your code, you always set it to 5. Also make sure to reset it when it reaches the max slider position.

You can check the SHIFT key inside the click:
var slide = 4;
$('body').click( function (e) {
if (e.shiftKey) {
slide++;
document.Captivate.cpEISetValue('m_VarHandle.cpCmndGotoSlide', slide);
}
});
check here

If you want to set a click with a shift key you can use this:
$(document).click(
function(e){
if(e.shiftKey){
document.Captivate.cpEISetValue('m_VarHandle.cpCmndGotoSlide', 5);
}
}
);
the same works with ctrlKey, and altKey
And to change the page fine you need a control variable like this:
var current_page = 1;
$(document).click(
function(e){
if(e.shiftKey){
current_page++
document.Captivate.cpEISetValue('m_VarHandle.cpCmndGotoSlide', current_page);
}
}
);
I think this is the final code that you need (you maybe need to change document to an id or class that you are using like "#element_id" or ".element_class")

Jquery keydown event only working every second press?

Essentially I've created a thumbnail gallery which you can scroll through using the left and right arrows. The right arrow event works perfectly fine, so I assumed that the left arrow event would be the same except with a (-) value. However when I press the left key it only goes to the previous thumbnail every SECOND time.
Can somebody take a look at my code and let me know what I'm missing? Thanks!
$(document).bind("keydown", function(event) {
if (event.keyCode == 39)
{
$("#thumbnail img").each(function(i) {
if ($(this).hasClass("currentThumb"))
{
currentSelectionIndex = i;
$("#thumbnail img").removeClass("currentThumb").addClass("thumb");
if (currentSelectionIndex == 14 && parseInt($('#end').text()) < parseInt($('#total').text()))
{
nextImages(currentCategory.value);
}
}
if(i == currentSelectionIndex + 1)
{
$(this).removeClass("thumb").addClass("currentThumb");
$(this).parent().click();
}
});
}
if (event.keyCode == 37)
{
$("#thumbnail img").each(function(i) {
if ($(this).hasClass("currentThumb"))
{
currentSelectionIndex = i;
$("#thumbnail img").removeClass("currentThumb");
$("#thumbnail img").addClass("thumb");
if (currentSelectionIndex == 0 && parseInt($('#start').text()) > 1)
{
prevImages(currentCategory.value);
}
}
if(i == currentSelectionIndex - 1)
{
$(this).removeClass("thumb").addClass("currentThumb");
$(this).parent().click();
}
});
}
});

Reversing your selection should be enough to make it go in reverse.
$.fn.reverse = [].reverse; // at the top of your code
// in the event handler for left arrow
$("#thumbnail img").reverse().each(function(i) {
don't forget to change back to +

It may works using keyup instead of keydown. I had some issues with it. If it doesn't work use http://jsfiddle.net so that we can easier solve it.

Jquery trigger on keypress

I am Using wordpress as cms
I have made a code which Runs a like() function when i press the left key
i try to trigger .love in like() Function
but it doesnt works
Here is my Code
var h2top = 0;
function like(){
scrollTop = jQuery(window).scrollTop();
jQuery('.container .post').each(function(i, h2){ /* loop through article headings */
h2top = jQuery(h2).offset().top ; /* get article heading top */
if (scrollTop<h2top-19) { /* compare if document is below heading */
alert("Ram");
jQuery(this).find('.love').trigger( "click" );
return false; /* exit function */
}
});
}
Here is the jquery code for Keypress events
jQuery(document).ready(function ($) {
$(document.documentElement).keyup(function (event) {
var direction = null;
// handle cursor keys
if (event.keyCode == 37) {
// go left
like();
$("#sad").closest('div').addClass('left');
alert("left");
} else if (event.keyCode == 39) {
// go right
alert("right");
}
});
});
Just using alert() to check whether the code is running or not

Just
$(document).keyup(function(e) {
alert (1);
// use event.which instead of keyCode
});
Instead of
$(document.documentElement).keyup(function (event) {
Other error, in your like function at the line jQuery(this).find('.love').trigger( "click" );
this is not the jQuery context, you must use $(this) like
jQuery($(this)).find('.love').trigger( "click" );
Example (updated)
http://jsbin.com/azUnUlO/1/

Fabric.js right mouse click

Is there a way to receive right click mouse events on a Fabric.js canvas?
The following code works only with left click:
canvas.observe('mouse:down', function(){console.log('mouse down'));

NOTE: Most answers above are outdated; this answer applies to the latest Fabric version 2.7.0
Simply enable firing right/middle click events for your Fabric canvas
The config for firing right click and middle click events in the canvas can be found here for fireRightClick and here for fireMiddleClick and are set to false by default. This means right and middle click events are by default disabled.
The parameter stopContextMenu for stopping context menu to show up on the canvas when right clicking can be found here
You can enable these simply by setting the values when creating your canvas:
var canvas = new fabric.Canvas('canvas', {
height: height,
width: width,
fireRightClick: true, // <-- enable firing of right click events
fireMiddleClick: true, // <-- enable firing of middle click events
stopContextMenu: true, // <-- prevent context menu from showing
});
Now your mousedown event will fire for all clicks and you can distinguish them by using the button identifier on the event:
For canvas:
canvas.on('mouse:down', (event) => {
if(event.button === 1) {
console.log("left click");
}
if(event.button === 2) {
console.log("middle click");
}
if(event.button === 3) {
console.log("right click");
}
}
For objects:
object.on('mousedown', (event) => {
if(event.button === 1) {
console.log("left click");
}
if(event.button === 2) {
console.log("middle click");
}
if(event.button === 3) {
console.log("right click");
}
}
When clicking on objects you can reach the "real" mouse dom event through event.e:
if(event.button === 3){
console.log(event.e);
}

I've implemented right click by extending the fabric.Canvas class. Take a look here the _onMouseDown method.
Basically the right mouse down event for an object was disabled in fabricjs by default.

If you want to handle right clicks (on canvas or its objects), then set context menu listener on upper-canvas element. Using canvas method findTarget you can check if any target was clicked and if so, you can check type of the target.
let scope = this;
jQuery(".upper-canvas").on('contextmenu', function (options: any) {
let target: any = scope.canvas.findTarget(options, false);
if (target) {
let type: string = target.type;
if (type === "group") {
console.log('right click on group');
} else {
scope.canvas.setActiveObject(target);
console.log('right click on target, type: ' + type);
}
} else {
scope.canvas.discardActiveObject();
scope.canvas.discardActiveGroup();
scope.canvas.renderAll();
console.log('right click on canvas');
}
options.preventDefault();
});

The way I did this was to listen for a right click event across the entire canvas and match up the x,y coordinates of the click event to the object which is currently sitting at the given location. This solution feels a little like a hack but hey, it works!
$('#my_canvas').bind('contextmenu', function (env) {
var x = env.offsetX;
var y = env.offsetY;
$.each (canvas._objects, function(i, e) {
// e.left and e.top are the middle of the object use some "math" to find the outer edges
var d = e.width / 2;
var h = e.height / 2;
if (x >= (e.left - d) && x <= (e.left+d)) {
if(y >= (e.top - h) && y <= (e.top+h)) {
console.log("clicked canvas obj #"+i);
//TODO show custom menu at x, y
return false; //in case the icons are stacked only take action on one.
}
}
});
return false; //stops the event propigation
});

Here's what I did, which makes use of some built-in fabric object detection code:
$('.upper-canvas').bind('contextmenu', function (e) {
var objectFound = false;
var clickPoint = new fabric.Point(e.offsetX, e.offsetY);
e.preventDefault();
canvas.forEachObject(function (obj) {
if (!objectFound && obj.containsPoint(clickPoint)) {
objectFound = true;
//TODO: whatever you want with the object
}
});
});