I am trying to develop a simple app.
When we drag the small box inside the bigger box, the smaller box should move inside the bigger box.
However, it can't go outside the bigger box. I know how to move the smaller box, but I don't know how to keep it inside the bigger box. Can somebody help me, please?
As I mentioned, my code moves the small box properly but does not keep it inside the bigger box.
var guy=document.getElementById("guy");
var cont=document.getElementById("container");
var lastX,lastY; // Tracks the last observed mouse X and Y position
guy.addEventListener("mousedown", function(event) {
if (event.which == 1) {
lastX = event.pageX;
lastY = event.pageY;
addEventListener("mousemove", moved);
event.preventDefault(); // Prevent selection
}
});
function buttonPressed(event) {
if (event.buttons == null)
return event.which != 0;
else
return event.buttons != 0;
}
function moved(event) {
if (!buttonPressed(event)) {
removeEventListener("mousemove", moved);
} else {
var distX = event.pageX - lastX;
var distY = event.pageY - lastY;
guy.style.left =guy.offsetLeft + distX + "px";
guy.style.top = guy.offsetTop + distY + "px";
lastX = event.pageX;
lastY = event.pageY;
}
}
#container {
height:400px;
width:600px;
outline: 1px solid black;
position:absolute;
left:50px;
top: 0px;
background-color:green;
}
#guy {
position:absolute;
height:50px;
width:50px;
outline: 1px solid black;
background-color:red;
left: 200px;
top: 200px;
}
<div id="container" draggable="true" ></div>
<div id="guy"></div>
You need to restrict guy's position to the container's bounds. In other words, guy's x position can at minimum be the container's x position, at maximum the container's x position plus the container's width minus guy's witdh. The same goes for the y axis, but with height instead of width.
var guy=document.getElementById("guy");
var cont=document.getElementById("container");
var lastX,lastY; // Tracks the last observed mouse X and Y position
var minX = cont.offsetLeft;
var maxX = minX + cont.offsetWidth - guy.offsetWidth;
var minY = cont.offsetTop;
var maxY = minY + cont.offsetHeight - guy.offsetHeight;
guy.addEventListener("mousedown", function(event) {
if (event.which == 1) {
lastX = event.pageX;
lastY = event.pageY;
addEventListener("mousemove", moved);
event.preventDefault(); // Prevent selection
}
});
function buttonPressed(event) {
if (event.buttons == null)
return event.which != 0;
else
return event.buttons != 0;
}
function moved(event) {
if (!buttonPressed(event)) {
removeEventListener("mousemove", moved);
} else {
var distX = event.pageX - lastX;
var distY = event.pageY - lastY;
var targetX = guy.offsetLeft + distX;
var targetY = guy.offsetTop + distY;
guy.style.left = Math.min(maxX, Math.max(minX, targetX)) + "px";
guy.style.top = Math.min(maxY, Math.max(minY, targetY)) + "px";
lastX = event.pageX;
lastY = event.pageY;
}
}
#container {
height:200px;
width:300px;
outline: 1px solid black;
position:absolute;
left:50px;
top: 0px;
background-color:green;
}
#guy {
position:absolute;
height:50px;
width:50px;
outline: 1px solid black;
background-color:red;
left: 100px;
top: 100px;
}
<div id="container" draggable="true" ></div>
<div id="guy"></div>
Related
I'm trying to trigger an event when the cursor position moves X amount of pixels, say 100px. So, for every 100px the cursor moves in either X or Y direction, I trigger an event. This should continue for every 100px movement.
I've successfully detected the 'current' X and Y position of the cursor, and have set a pixel threshold, but am struggling with the maths on the rest. Can anyone help?
$(window).on('mousemove', function(e){
// Vars
var cursorX = e.clientX;
var cursorY = e.clientY;
var cursorThreshold = 100;
... detect every 100px movement here...
});
You need to keep track of the old cursor positions. Then you can calculate the distance using the Pythagorean theorem:
totalDistance += Math.sqrt(Math.pow(oldCursorY - cursorY, 2) + Math.pow(oldCursorX - cursorX, 2))
This works in any direction.
Example:
Note: Unlike #wayneOS's approach (+1 from me) I do not keep track of the direction.
It's a rather minimalistic implementation.
var totalDistance = 0;
var oldCursorX, oldCursorY;
$(window).on("mousemove", function(e){
var cursorThreshold = 100;
if (oldCursorX) totalDistance += Math.sqrt(Math.pow(oldCursorY - e.clientY, 2) + Math.pow(oldCursorX - e.clientX, 2));
if (totalDistance >= cursorThreshold){
console.log("Mouse moved 100px!");
totalDistance = 0;
}
oldCursorX = e.clientX;
oldCursorY = e.clientY;
});
.d {
width: 0;
height: 0;
border-style: solid;
border-width: 100px 100px 0 0;
border-color: #e54646 transparent transparent transparent;
}
.s { display: flex; }
.p1 { margin-left: 100px; }
.p2 { margin-right: 20px; padding-top: 20px; }
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<p class="p1">100px X</p>
<div class="s">
<p class="p2">100px Y</p>
<div class="d"></div>
</div>
To track mouse-movement for defined steps, you just need to save the last position and than check if the cursor has moved more than the threshold in one direction. Here is an example:
// Vars
var lastCursorX = null;
var lastCursorY = null;
var cursorThreshold = 100;
$(window).on('mousemove', function(e){
//set start-points
if (lastCursorX === null)
lastCursorX = e.clientX;
if (lastCursorY === null)
lastCursorY = e.clientY;
//check for move left
if (e.clientX <= lastCursorX - cursorThreshold) {
lastCursorX = e.clientX;
console.log (cursorThreshold + 'px moved left');
}
//check for move right
if (e.clientX >= lastCursorX + cursorThreshold) {
lastCursorX = e.clientX;
console.log (cursorThreshold + 'px moved right');
}
//check for move up
if (e.clientY <= lastCursorY - cursorThreshold) {
lastCursorY = e.clientY;
console.log (cursorThreshold + 'px moved up');
}
//check for move down
if (e.clientY >= lastCursorY + cursorThreshold) {
lastCursorY = e.clientY;
console.log (cursorThreshold + 'px moved down');
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
I have an element which I would like to move with the mouse.
var troll = document.getElementById('troll');
troll.addEventListener('dragover', (e) => {
e.preventDefault();
e.target.style.left = e.clientX + 'px';
e.target.style.top = e.clientY + 'px';
}, false);
img {
width: 100px;
cursor: pointer;
position: absolute;
}
<div id="troll">
<img src="http://images.mmorpg.com/features/7909/images/Troll.png" alt="Troll">
</div>
From left to right and from top to bottom it works OK. Not perfect, since the very first move takes a whole space and it doesn't look smooth. But the main problem is that I can't move from right to left or from bottom to top.
Any help would be appreciated.
You wanna use drag not dragover, and some logic to know where you're going up or down or left or top.
var troll = document.getElementById('troll');
var X,Y = 0;
troll.addEventListener('drag', (e) => {
e.preventDefault();
if (e.clientX > X)
{
e.target.style.left = X + 'px';
}
else if (e.clientX < X)
{
e.target.style.left = X-- + 'px';
}
if (e.clientY > Y)
{
e.target.style.top = Y + 'px';
}
else if (e.clientY < Y)
{
e.target.style.top = Y-- + 'px';
}
X = e.clientX;
Y = e.clientY;
}, false);
img {
width: 100px;
cursor: pointer;
position: absolute;
}
<div id="troll">
<img src="http://images.mmorpg.com/features/7909/images/Troll.png" alt="Troll">
</div>
I am trying to make a web app with two boxes, one contained in the other. The user should be able to click and move the inner box, however, the user should not be able to move this box outside the confines of the outer box. The user can move the outer box by dragging the inner box against one of the edges of the outer box. I know how to move the inner box, but the problem is how to move the other box with this restriction. Can anybody help me please? Here is what I did so far:
<!doctype html>
<head>
<title>JavaScript Game</title>
<style>
#container {
height:400px;
width:600px;
outline: 1px solid black;
position:absolute;
left:50px;
top: 0px;
background-color:green;
}
#guy {
position:absolute;
height:50px;
width:50px;
outline: 1px solid black;
background-color:red;
left: 200px;
top: 200px;
}
</style>
</head>
<body>
<div id="container"></div>
<div id="guy"></div>
<script>
var guy=document.getElementById("guy");
var cont=document.getElementById("container");
var lastX,lastY; // Tracks the last observed mouse X and Y position
guy.addEventListener("mousedown", function(event) {
if (event.which == 1) {
lastX = event.pageX;
lastY = event.pageY;
addEventListener("mousemove", moved);
event.preventDefault(); // Prevent selection
}
});
function buttonPressed(event) {
if (event.buttons == null)
return event.which != 0;
else
return event.buttons != 0;
}
function moved(event) {
if (!buttonPressed(event)) {
removeEventListener("mousemove", moved);
} else {
var distX = event.pageX - lastX;
var distY = event.pageY - lastY;
guy.style.left =guy.offsetLeft + distX + "px";
guy.style.top = guy.offsetTop + distY + "px";
lastX = event.pageX;
lastY = event.pageY;
}
}
</script>
</body>
You could add a check to see if moving the box would break bounds of cont.
try to use getBoundingClientRect()
Check the snippet below for the working code.
View in full screen for best results.
var guy=document.getElementById("guy");
var cont=document.getElementById("container");
var lastX,lastY; // Tracks the last observed mouse X and Y position
guy.addEventListener("mousedown", function(event) {
if (event.which == 1) {
lastX = event.pageX;
lastY = event.pageY;
addEventListener("mousemove", moved);
event.preventDefault(); // Prevent selection
}
});
function buttonPressed(event) {
if (event.buttons == null)
return event.which != 0;
else
return event.buttons != 0;
}
function moved(event) {
if (!buttonPressed(event)) {
removeEventListener("mousemove", moved);
} else {
var distX = event.pageX - lastX;
var distY = event.pageY - lastY;
guy.style.left =guy.offsetLeft + distX + "px";
guy.style.top = guy.offsetTop + distY + "px";
// ********************************************************************
// get bounding box borders
var contBounds = guy.getBoundingClientRect();
var guyBounds = cont.getBoundingClientRect();
// check bottom bounds
if (contBounds.bottom >= guyBounds.bottom){
cont.style.top = cont.offsetTop + distY + "px";
}
// check top bounds
if (contBounds.top <= guyBounds.top){
cont.style.top = cont.offsetTop + distY + "px";
}
// check left bounds
if (contBounds.left <= guyBounds.left){
cont.style.left = cont.offsetLeft + distX + "px";
}
// check right bounds
if (contBounds.right >= guyBounds.right){
cont.style.left = cont.offsetLeft + distX + "px";
}
// ********************************************************************
lastX = event.pageX;
lastY = event.pageY;
}
}
#container {
height:300px;
width:300px;
outline: 1px solid black;
position:absolute;
left:50px;
top: 0px;
background-color:#CCC;
}
#guy {
position:absolute;
height:50px;
width:50px;
outline: 1px solid black;
background-color:#000;
left: 200px;
top: 200px;
}
<div id="container"></div>
<div id="guy"></div>
try this link to get you started as far as keeping the "guy" inside the "contatiner": http://www.w3schools.com/html/html5_draganddrop.asp
their example shows how you can make an element only drop inside another element.
as far as moving the container...i would think that you could add some if else statements into the moved function that will test the position of the guy against the conatiner's outline and say that when they meet to move the container as well.
i am very new to javascript myself but this is just a suggestion from what i think i understand of it.
Why when the ball is placed relative positioning when you press the mouse it bounces? Absolute positioning is when this doesn't happen.
var ball = document.querySelector('.ball');
ball.onmousedown = function(event) {
var shiftX = event.pageX - getCoords(this).left,
shiftY = event.pageY - getCoords(this).top;
this.style.position = 'relative';
this.zIndex = 10000;
function move(event) {
this.style.left = event.pageX - shiftX + 'px';
this.style.top = event.pageY - shiftY + 'px';
}
move.call(this, event);
document.onmousemove = function(event) {
move.call(ball, event);
};
this.onmouseup = function(event) {
document.onmousemove = this.onmouseup = null;
};
return false;
};
ball.ondragstart = function() {
return false;
};
function getCoords(elem) {
var box = elem.getBoundingClientRect();
return {
top: box.top + window.pageYOffset,
left: box.left + window.pageXOffset
};
}
body {
margin: 50px;
}
img {
cursor: pointer;
}
<img class="ball" src="https://js.cx/clipart/ball.svg" alt="" />
I guess it's because of the padding of the body element. Please explain.
it seems i found answer
Implementing drag and drop on relatively positioned elements in JavaScript
and as it says, with relative position, your element contain offset of all objects in his parent-tag
and parent's margin and padding too
so when you try to get elemtn's position, you should count it's real offset in parent, see in my code example work with count index
<html>
<body>
<div id=obj1 style="width:100px; height:100px; background:#000; position:relative; " ></div>
<div id=obj2 style="width:100px; height:100px; background:#000; position:relative; " ></div>
<div id=obj3 style="width:100px; height:100px; background:#000; position:relative; " ></div>
<script>
var dragObj, count=0;
function set_drag_drop(obj)
{
if(count>0){
// count margins and divs offset
// body{ margin:10px; }
// height:100px;
obj.adx = 10;
obj.ady = 10 + (count*100)
}else{
obj.adx = 0;
obj.ady = 0;
}
count++;
obj.onmousedown = function(e)
{
var rect = obj.getBoundingClientRect();
obj.dx = rect.left - e.clientX;
obj.dy = rect.top - e.clientY;
obj.isDown = true;
dragObj = this;
}
obj.onmouseup = function(e)
{
obj.isDown = false;
}
document.onmousemove = function(e)
{
if(dragObj && dragObj.isDown)
{
dragObj.style.left = e.pageX -dragObj.adx+ dragObj.dx +"px";
dragObj.style.top = e.pageY -dragObj.ady+ dragObj.dy + "px";
}
}
}
set_drag_drop(document.getElementById("obj1"));
set_drag_drop(document.getElementById("obj2"));
set_drag_drop(document.getElementById("obj3"));
</script>
</html>
I am tying the placing of an input box to the mouseX and mouseY coordinates, but my issue is that when I click I can only click in a small diagonal field across the body. I want it so that I can click anywhere on the body and it will go to that location. Any ideas on how to fix this peculiar problem?
<body onclick = "getLocation(event)">
<style>
html{
}
div{
display: block;
}
textarea, input {
clear: both;
position: relative;
}
textarea, input {
overflow: auto;
width: 20%;
}
</style>
<input id = "enter" placeholder = "input" style = "top:20;left:40;"></input>
</body>
<script>
function getLocation(event){
var y = event.clientY;
var x = event.clientY;
console.log("Y:" + y + " X:" + x);
document.getElementById("enter").style.left = x;
document.getElementById("enter").style.top = y;
}
</script>
You need to set the width and height of the body. You also need to set units on the positions and you most likely want to use pageX and pageY, not clientX and clientY
function getLocation(event){
var y = event.pageY;
var x = event.pageX ;
console.log("Y:" + y + " X:" + x);
document.getElementById("enter").style.left = x + "px";
document.getElementById("enter").style.top = y + "px";
}
document.body.addEventListener("click", getLocation);
html, body{
width:100%;
height:100%;
}
div{
display: block;
}
textarea, input {
clear: both;
position: relative;
}
textarea, input {
overflow: auto;
width: 20%;
}
<input id="enter" placeholder="input" style="top:20px;left:40px;"></input>
<script>
function getLocation(event){
document.getElementById('enter').style.left = (window.Event) ? event.pageX : event.clientX + (document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft);
document.getElementById('enter').style.top = (window.Event) ? event.pageY : event.clientY + (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop);
}
</script>
Just replace this, and it works :)