Develop Reference

Re-sizing Image Width Using JavaScript

I am trying to re-size an image in a popup. The original image is 6000 x 4000. I do a check to see if the image is greater than 500, and if so I just try and set the image to 500. Trying to set it using 'this', makes the pop open in a tab and the image is still its original size. If I try and set the image not using 'this', the pop up works as intended regarding where it is positioned on screen and the size of the box, but the image, is still its original size--6000 x 4000. (PS: I have to use ES5 as well.)
What gives?
Thanks,
CM
<script language="javascript" type="text/javascript"><!--
// let i=0;
function resize() {
console.log("Testing");
let i=0;
if (window.navigator.userAgent.indexOf('MSIE 6.0') != -1 && window.navigator.userAgent.indexOf('SV1') != -1) {
i=30; //This browser is Internet Explorer 6.x on Windows XP SP2
} else if (window.navigator.userAgent.indexOf('MSIE 6.0') != -1) {
i=0; //This browser is Internet Explorer 6.x
} else if (window.navigator.userAgent.indexOf('Firefox') != -1 && window.navigator.userAgent.indexOf("Windows") != -1) {
i=25; //This browser is Firefox on Windows
} else if (window.navigator.userAgent.indexOf('Mozilla') != -1 && window.navigator.userAgent.indexOf("Windows") != -1) {
i=45; //This browser is Mozilla on Windows
} else {
i=80; //This is all other browsers including Mozilla on Linux
}
var imgWidth = document.images[0].width;
var imgHeight = document.images[0].height;
console.log("Original image width is: " + imgWidth);
console.log("Original image height is: " + imgHeight);
if(imgWidth > 500){
//Shrink the image to size of popup frame
this.imgWidth = 500;
this.imgHeight = 500;
console.log("Adjusted image width is: " + imgWidth);
console.log("Adjusted image height is: " + imgHeight);
//Get display/screen width and height
var screenWidth = screen.width;
var screenHeight = screen.height;
console.log("Screen width is: " + screenWidth);
console.log("Screen height is: " + screenHeight);
//Set popup position on display/screen
var leftpos = screenWidth / 2 ;
var toppos = screenHeight / 2 - imgHeight / 2;
console.log("Left position is: " + leftpos);
console.log("Top position is: " + toppos);
//Set popup frame width and height equal to adjusted image width and height
var frameWidth = imgWidth;
var frameHeight = imgHeight+i;
console.log("Frame width is: " + frameWidth);
console.log("Frame height is: " + frameHeight);
window.moveTo(leftpos, toppos);
window.resizeTo(frameWidth,frameHeight+i);
}
else if (document.documentElement && document.documentElement.clientWidth) {
var imgHeight = document.images[0].height + 40 - i;
var imgWidth = document.images[0].width + 20;
var height = screen.height;
var width = screen.width;
var leftpos = width / 2 - imgWidth / 2;
var toppos = height / 2 - imgHeight / 2;
frameWidth = imgWidth;
frameHeight = imgHeight + i;
window.moveTo(leftpos, toppos);
window.resizeTo(frameWidth, frameHeight + i);
} else if (document.body) {
window.resizeTo(document.body.clientWidth, document.body.clientHeight - i);
}
self.focus();
}//end resize() function
//--></script>

Use
var imgWidth = document.images[0].style.width;
instead of
var imgWidth = document.images[0].width;

Iframe height definition in IE 7

I have a problem with resizing iframe content in IE7.
I have an external iframe
<IFRAME id=fl_game src="my_iframe_page" frameBorder=0 allowTransparency scrolling=no></IFRAME>
with width=100%, height=93%
and add my page into it. Here is a page body
<div id="container">
<div id="game-box">
<div id="flashcontent">
</div>
</div>
</div>
<script type="text/javascript">
swfobject.embedSWF("<%=application.getContextPath()%>/flash/<%= request.getParameter(PARAM_GAME) %>/game.swf", "flashcontent", gameWidth, gameHeight, "10.1", "/flash/expressInstall.swf", flashvars, params);
</script>
On my page I add resize events.
if (window.addEventListener) {
window.addEventListener("load", resizeGame, false);
window.addEventListener("resize", resizeGame, false);
} else if (window.attachEvent) {
window.attachEvent("onload", resizeGame);
window.attachEvent("onresize", resizeGame);
} else {
window.onload = function() {resizeGame();};
window.onresize = function() {resizeGame();}
}
Here is my resizeGame function
function resizeGame(isIEResize) {
var flash = document.getElementById('flashcontent');
var screen = screenSize();
var width = screen.width;
var height = screen.height;
var left = 0;
var top = 0;
if (height * 1.5 > width) {
height = width / 1.5
} else {
width = height * 1.5;
}
flash.width = width;
flash.height = height;
document.getElementById('flashcontent').style.width = width + 'px';
document.getElementById('flashcontent').style.height = height + 'px';
document.getElementById('flashcontent').style.top = '50%';
document.getElementById('flashcontent').style.left = '50%';
if (width < screen.width) {
left = (screen.width - width) / 2 + left;
}
if (height < screen.height) {
top = (screen.height - height) / 2;
}
document.getElementById('game-box').style.top = top + 'px';
document.getElementById('game-box').style.left = left + 'px';
}
function screenSize() {
var w, h;
w = (window.innerWidth ? window.innerWidth : (document.documentElement.clientWidth ? document.documentElement.clientWidth : document.body.offsetWidth));
h = (window.innerHeight ? window.innerHeight : (document.documentElement.clientHeight ? document.documentElement.clientHeight : document.body.offsetHeight));
return {width:w, height:h};
}
And here is a question:
In IE7 function screenSize() gives me wrong height on load. Under other browsers and IE>7 function screenSize() gives me correct height. That's why I can't resize my content properly.
And when I explicitly resize a window, function screenSize() starts to give correct height.
Here some screens before explicit resizing and after it.
screenSize() gives strange height ONLY in IE7.
I am ready to add any extra information to find a reason of this situation.
I hope someone can help me to find out how to define iframe height in IE7. Any help will be useful.

Fill box dynamically with screen height

I have a box, which I am trying to size perfectly to fit within the browser viewport if the image is not larger then it. So the image would appear to be centered within the window.
Currently I don' think my method of seeking the browser height is working. And for some reason there is a lot of extra space
Example (src)
here is where I define the page sizes
if ( style['img-width'] > screenwidth ) {
style['body-width'] = style['img-width'] + ( style['img-padding'] * 2 );
} else {
style['body-width'] = screenwidth;
}
style['body-height'] = ( style['img-height'] > screenheight ) ?
( style['img-height'] +
( style['img-padding'] * 2 ) +
style['header-height']
) :
screenheight;
$('body').css({ 'width': style['body-width']+'px' });
theater.css({
'width': style['body-width']+'px',
'height': style['body-height']+'px',
});
theaterheadcon.css('width', style['body-width']+'px');
theaterheader.css('width', style['body-width']+'px');
How I am defining screen width/height
screenwidth = isNaN(window.outerWidth) ? window.clientWidth : window.outerWidth,
screenheight = isNaN(window.outerHeight) ? window.clientHeight : window.outerHeight;

Here is the basic of centering items to a content with javascript and css:
/*css*/
#myImage
{
position:absolute;
}
And in java:
/*javascript*/
var img=$('#myImage');
var winWidth=$(window).width();
var winHeight=$(window).height();
if(img.height()>winHeight)
{
img.css('height', winHeight + "px");
}
img.css('left',(winWidth/2) + "px");
img.css('top',(winHeight/2) + "px");
img.css('margin-left',(-(img.width()/2)) + "px");
img.css('margin-top',(-(img.height()/2)) + "px");
The margin approach guaranties that the image will stay at the center even on page resize

I tried here in DIVs in your case code will detect your image size itself
$(document).ready(function(){
var windowheight = $(window).height();
var windowwidth = $(window).width();
var boxheight = $('#box').outerHeight();
var boxwidth = $('#box').outerWidth();
var imgheight = $('.img').outerHeight();
var imgwidth = $('.img').outerWidth();
if(imgheight > boxheight || imgwidth > boxwidth){
$('#box').css('height', windowheight).css('width', windowwidth);
$('.img').css('margin-left',((windowwidth - imgwidth)/2)+'px');
$('.img').css('margin-top',((windowheight - imgheight)/2)+'px');
}
});
DEMO
change your img width in css to see the action
if you want your div to not going outside the window after margin the image to center use that code
$(document).ready(function(){
var windowheight = $(window).height();
var windowwidth = $(window).width();
var boxheight = $('#box').outerHeight();
var boxwidth = $('#box').outerWidth();
var imgheight = $('.img').outerHeight();
var imgwidth = $('.img').outerWidth();
if(imgheight > boxheight || imgwidth > boxwidth){
$('#box').css('position','absolute').css('width', 'auto').css('height', 'auto').css('left', '0').css('top', '0').css('right', '0').css('bottom', '0');
$('.img').css('margin-left',((windowwidth - imgwidth)/2)+'px');
$('.img').css('margin-top',((windowheight - imgheight)/2)+'px');
}
});
DEMO

change height of div to browser window height so long a the browser height is greater than x

Hi I'm hoping someone will be able to explain what i am doing wrong here:
var winHeight = $(window).height(),
minHeight = 900,
Height = 900;
$(document).ready(function () {
if (winHeight < MinHeight) {
Height = minHeight;
} else {
Height = winHeight;
}
$('div.page').css('height', winHeight + 'px');
});
$(window).resize(function () {
if (winHeight < MinHeight) {
Height = minHeight;
} else {
Height = winHeight;
}
$('div.page').css('height', winHeight + 'px');
});
On my page I have multiple divs with the class "page".
I'm trying make the height of these the size of the browser window, unless the browser window is less than 900, then I want them to be 900px tall.
I'm guessing its a syntax issue. Especially since I'm brand new to jquery and javascript ( I only started using it today).

You have to call $(window).height() on the resize event, so you can respond to the current window size. You can go with this:
$(document).ready(function () {
//Call the method one time
updateWindowSize();
//Subscribe the method to future resize events
$(window).resize(updateWindowSize);
//updateWindowSize inside a closure to hide 'minHeight'
var updateWindowSize = (function(){
var minHeight = 900;
//Actual updateWindowSize function
return function(){
var winHeight = $(window).height();
var newHeight = winHeight < minHeight ? minHeight : winHeight;
$('div.page').height(newHeight);
}
})();
});

The problem is the value of winHeight is never changed when window resizes. And I wonder where the variable "Height" is used ?
The code should be:
$(document).ready(function () {
$(window).resize(function () {
var winHeight = $(window).height(),
minHeight = 900,
Height = 900;
if (winHeight < minHeight) {
Height = minHeight;
} else {
Height = winHeight;
}
$('div.page').height(Height);
});
});
Make sense?

"Zooming" elements on a page while keeping the centre of enlargement in the centre of the window

I'm trying to work out how to enlarge all elements on a page, but keep the centre of enlargement in the centre of the window.
On this page, once the image reaches the top or the left side of the window the centre of enlargement changes. It also changes when you move the image. (exactly what you would expect)
I'm thinking I'd need to take a completely different approach to achieve what I want. But I'm not sure what that approach is..
Any ideas?

Well, here's my take.
Only thing is that I ditched the containers you were using. Is that cheating? Seems like they were only there to get the image centered. No need.
This works as expected with no side effects.
Here's a working demo you can test:
http://jsfiddle.net/YFPRB/1/
(You need to click on the pane with the baboon first.)
HTML
<body>
<img src="http://cdn.sstatic.net/stackoverflow/img/apple-touch-icon.png" />
</body>
CSS
html, body {
width: 100%;
height: 100%;
overflow: hidden;
}​
jQuery
EDIT: Thanks to #stagas for the reminder to clean up redundancies.
var $img = $('img'); // Cache the image. Better for performance.
$img.draggable();
$img.css({left: ($('body').width() / 2) - ($img.width() / 2)})
.css({top: ($('body').height() / 2) - ($img.height() / 2)})
$(document).keydown(function(event) {
if (event.keyCode == 38) {
var adjustment = 1.25;
} else if (event.keyCode == 40) {
var adjustment = 0.8;
} else {
return;
}
var offset = $img.offset();
var width = $img.width();
var height = $img.height();
var newWidth = width * adjustment;
var newHeight = height * adjustment;
var diffWidth = newWidth - width;
var diffHeight = newHeight - height;
var hcenter = $('body').width() / 2;
var vcenter = $('body').height() / 2;
var leftPercent = (hcenter - offset.left) / width;
var topPercent = (vcenter - offset.top) / height;
$img.offset({top: offset.top - (diffHeight * topPercent), left: offset.left - (diffWidth * leftPercent)});
$img.width(newWidth).height(newHeight);
});​

This is what I came up, it works as you say except the image will always go to the center after zooming in or out:
$('document').ready(function() {
zoomimg=$('#zoomimg'); // we store this in a variable since we don't need to traverse the DOM every time -- this is faster
var viewportWidth = $(window).width();
var viewportHeight = window.innerHeight ? window.innerHeight : $(window).height(); // this is to work with Opera
zoomimg.css({'position': 'absolute', 'left': (viewportWidth/2)-(zoomimg.width()/2), 'top' : (viewportHeight/2)-(zoomimg.height()/2)}).draggable();
$(document).keydown(function(event) {
event = event || window.event;
var viewportWidth = $(window).width();
var viewportHeight = window.innerHeight ? window.innerHeight : $(window).height(); // this is to work with Opera
if (event.keyCode == 38) {
width = zoomimg.width();
height = zoomimg.height();
zoomimg.width(width*1.2).height(height*1.2);
var viewportWidth = $(window).width();
var viewportHeight = window.innerHeight ? window.innerHeight : $(window).height();
zoomimg.css({'left': (viewportWidth/2)-(zoomimg.width()/2), 'top' : (viewportHeight/2)-(zoomimg.height()/2)});
} else if (event.keyCode == 40) {
width = zoomimg.width();
height = zoomimg.height();
zoomimg.width(width*0.8).height(height*0.8);
var viewportWidth = $(window).width();
var viewportHeight = window.innerHeight ? window.innerHeight : $(window).height();
zoomimg.css({'left': (viewportWidth/2)-(zoomimg.width()/2), 'top' : (viewportHeight/2)-(zoomimg.height()/2)});
} else {
return
}
});
});
You should put an ID 'zoomimg' on the tag for it to work, and overflow:hidden on the #container . Also ditch that display:table and display:table-cell they're useless now that we center with Javascript. Also, pressing the down arrow key will cause the container to scroll down, so you should use other keys, as the arrows are reserved by the browser for scrolling the viewport.