Голову ломаю на тем как увеличенное svg изображение можно двигать в браузере. Может какая функция есть или способ?
у меня тяжелая схема примерно как целая карта которую мне надо увеличивать и двигать
Вот что я наделал:
var leftArrow = 37; // The numeric code for the left arrow key.
var upArrow = 38;
var rightArrow = 39;
var downArrow = 40;
var panRate = 10; // Number of pixels to pan per key press.
var zoomRate = 1.1; // Must be greater than 1. Increase this value for faster zooming (i.e., less granularity).
var x;
var y;
/* Globals: */
var theSvgElement;
function processKeyPress(evt)
{
var viewBox = theSvgElement.getAttribute('viewBox'); // Grab the object representing the SVG element's viewBox attribute.
var viewBoxValues = viewBox.split(' '); // Create an array and insert each individual view box attribute value (assume they're seperated by a single whitespace character).
viewBoxValues[0] = parseFloat(viewBoxValues[0]); // Convert string "numeric" values to actual numeric values.
viewBoxValues[1] = parseFloat(viewBoxValues[1]);
switch (evt.keyCode)
{
case leftArrow:
viewBoxValues[0] += panRate; // Increase the x-coordinate value of the viewBox attribute to pan right.
break;
case rightArrow:
viewBoxValues[0] -= panRate; // Decrease the x-coordinate value of the viewBox attribute to pan left.
break;
case upArrow:
viewBoxValues[1] += panRate; // Increase the y-coordinate value of the viewBox attribute to pan down.
break;
case downArrow:
viewBoxValues[1] -= panRate; // Decrease the y-coordinate value of the viewBox attribute to pan up.
break;
} // switch
theSvgElement.setAttribute('viewBox', viewBoxValues.join(' ')); // Convert the viewBoxValues array into a string with a white space character between the given values.
}
function drag(evt) {
ev.dataTransfer.setData('svg-id', evt.target.id);
}
function zoom(zoomType)
{
var viewBox = theSvgElement.getAttribute('viewBox'); // Grab the object representing the SVG element's viewBox attribute.
var viewBoxValues = viewBox.split(' '); // Create an array and insert each individual view box attribute value (assume they're seperated by a single whitespace character).
viewBoxValues[2] = parseFloat(viewBoxValues[2]); // Convert string "numeric" values to actual numeric values.
viewBoxValues[3] = parseFloat(viewBoxValues[3]);
if (zoomType == 'zoomIn')
{
viewBoxValues[2] /= zoomRate; // Decrease the width and height attributes of the viewBox attribute to zoom in.
viewBoxValues[3] /= zoomRate;
}
else if (zoomType == 'zoomOut')
{
viewBoxValues[2] *= zoomRate; // Increase the width and height attributes of the viewBox attribute to zoom out.
viewBoxValues[3] *= zoomRate;
}
else
alert("function zoom(zoomType) given invalid zoomType parameter.");
theSvgElement.setAttribute('viewBox', viewBoxValues.join(' ')); // Convert the viewBoxValues array into a string with a white space character between the given values.
var currentZoomFactor = svgViewBoxWidth / viewBoxValues[2]; // Calculates the current zoom factor, could have just as easily used svgViewBoxHeight.
var newText = document.createTextNode("Current zoom factor = " + currentZoomFactor.toFixed(3)); // Create a generic new text node object.
var parentNode = document.getElementById('currentZoomFactorText'); // Get the parent node of the text node we want to replace.
parentNode.replaceChild(newText, parentNode.firstChild); // Replace the first child text node with the new text object.
}
function zoomViaMouseWheel(mouseWheelEvent)
{
if (mouseWheelEvent.wheelDelta > 0)
zoom('zoomIn');
else
zoom('zoomOut');
/* When the mouse is over the webpage, don't let the mouse wheel scroll the entire webpage: */
mouseWheelEvent.cancelBubble = false;
return false;
}
function initialize()
{
/* Add event listeners: */
window.addEventListener('keydown', processKeyPress, true); // OK to let the keydown event bubble.
window.addEventListener('mousewheel', zoomViaMouseWheel, false); // Don't let the mousewheel event bubble up to stop native browser window scrolling.
/* Set a global variable and detect if the browser supports SVG: */
theSvgElement = document.getElementById('svg-id'); // Best to only access the SVG element after the page has fully loaded.
document.addEventListener("drag", function( event ) {
}, false);
if(theSvgElement.namespaceURI != "http://www.w3.org/2000/svg") // Alert the user if their browser does not support SVG.
alert("Inline SVG in HTML5 is not supported. This document requires a browser that supports HTML5 inline SVG.");
/* For the svg element, specifically set the viewBox attribute's width and height values in that one of them will be used to calculate the current scaling factor. */
theSvgElement.setAttribute('viewBox', "0 0 " + svgViewBoxWidth + " " + svgViewBoxHeight);
}
