Kison Kison - 4 months ago 22
HTML Question

Need to fit application width to device width

What do i have?


  1. Web app(just html,css,js), application has fixed width and height (1024*768);

  2. Android application created with cordova by web application;

  3. Testing android application on htc desire 500 (android version 4.1.2)



Problem:
I need width of application fit to device width on all android devices. Now my application is bigger then device width.

What i tried to do?

Changed viewport meta tag in different ways like

<meta name="viewport" content="width=device-width, user-scalable=no" />


Used javascript to change app zoom (on deviceredy event)

var contentWidth = document.body.scrollWidth,
windowWidth = window.innerWidth,
newScale = windowWidth / contentWidth;
document.body.style.zoom = newScale;


Used javascript to change viewport

var ww = (jQuery(window).width() < window.screen.width) ?
jQuery(window).width() : window.screen.width;
// min width of site
var mw = 1020;
//calculate ratio
var ratio = ww / mw;
if (ww < mw) {
jQuery('meta[type="viewport"]').attr('content', 'initial-scale=' + ratio + ', maximum-scale=' + ratio + ', minimum-scale=' + ratio + ', user-scalable=yes, width=' + ww);
} else {
jQuery('meta[type="viewport"]').attr('content', 'initial-scale=1.0, maximum-scale=2, minimum-scale=1.0, user-scalable=yes, width=' + ww);
}


But solutions that i describe above can`t help. Do anyone knows solution that can help do that i need?

Answer

I have solved problem by using css transform, this css property is similar to zoom but it is supported by all modern browsers. Notice: This solution appropriate just for fixed size layouts

Function that i wrote to solve my problem (Just put body as element, and it initial size as height and width):

/**
 * @param {string} element - element to apply zooming
 * @param {int} width - initial element width
 * @param {int} height - initial element heigth
 * @param {float} desiredZoom - which zoom you need, default value = 1
 */    
function zoomElement(element, width, height, desiredZoom) {
        desiredZoom = desiredZoom || 1;
        var zoomX = (jQuery(window).width() * desiredZoom) / width,
            zoomY = (jQuery(window).height() * desiredZoom) / height,
            zoom = (zoomX < zoomY) ? zoomX : zoomY;

        jQuery(element)
            .css('transform', 'scale(' + zoom + ')')
            .css('transform-origin', '0 0')
            // Internet Explorer
            .css('-ms-transform', 'scale(' + zoom + ')')
            .css('-ms-transform-origin', '0 0')
            // Firefox
            .css('-moz-transform', 'scale(' + zoom + ')')
            .css('-moz-transform-origin', '0 0')
            // Opera
            .css('-o-transform', 'scale(' + zoom + ')')
            .css('-o-transform-origin', '0 0')
            // WebKit
            .css('-webkit-transform', 'scale(' + zoom + ')')
            .css('-webkit-transform-origin', '0 0');

        // Center element in it`s parent
        (function () {
            var $element = jQuery(element);

            // Remove previous timeout
            if ($element.data('center.timeout')) {
                console.log("clear timeout");
                clearTimeout($element.data('center.timeout'));
            }

            var timeout = setTimeout(function () {
                $element.data('center.timeout', timeout);
                var parentSize = {
                        'height' : $element.parent().height(),
                        'width' : $element.parent().width()
                    },
                    rect = element.get(0).getBoundingClientRect();

                element.css({
                    'marginTop' : 0,
                    'marginLeft' : 0
                });

                // Center vertically
                if (parentSize.height > rect.height) {
                    var marginTop = (parentSize.height - rect.height) / 2;
                    element.css('marginTop', marginTop);
                }

                // Center horizontally
                if (parentSize.width > rect.width) {
                    var marginLeft = (parentSize.width - rect.width) / 2;
                    element.css('marginLeft', marginLeft);
                }
            }, 300);
        })();
    }
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