Here is my html file:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<script src="signature.js"></script>
</head>
<body>
<div id="canvas">
<canvas class="roundCorners" id="newSignature"
style="position: relative; margin: 0; padding: 0; border: 1px solid #c4caac;"></canvas>
</div>
<script>signatureCapture();</script>
<button type="button" onclick="signatureSave()">Save signature</button>
<button type="button" onclick="signatureClear()">Clear signature</button>
<img id="saveSignature" alt="Saved image png" hidden/>
<script>
var img = document.images[0];
img.onclick = function() {
var url = img.src.replace(/^data:image\/[^;]/, 'data:application/octet-stream');
};
</script>
</body>
</html>
And here is javascript file:
function signatureCapture() {
var canvas = document.getElementById("newSignature");
//next record was commented
//window.open(canvas.toDataURL("image/png"));
var context = canvas.getContext("2d");
canvas.width = 500;
canvas.height = 500;
context.fillStyle = "#fff";
context.strokeStyle = "#444";
context.lineWidth = 1.5;
context.lineCap = "round";
context.fillRect(0, 0, canvas.width, canvas.height);
var disableSave = true;
var pixels = [];
var cpixels = [];
var xyLast = {};
var xyAddLast = {};
var calculate = false;
{ //functions
function remove_event_listeners() {
canvas.removeEventListener('mousemove', on_mousemove, false);
canvas.removeEventListener('mouseup', on_mouseup, false);
canvas.removeEventListener('touchmove', on_mousemove, false);
canvas.removeEventListener('touchend', on_mouseup, false);
document.body.removeEventListener('mouseup', on_mouseup, false);
document.body.removeEventListener('touchend', on_mouseup, false);
}
function get_coords(e) {
var x, y;
if (e.changedTouches && e.changedTouches[0]) {
var offsety = canvas.offsetTop || 0;
var offsetx = canvas.offsetLeft || 0;
x = e.changedTouches[0].pageX - offsetx;
y = e.changedTouches[0].pageY - offsety;
} else if (e.layerX || 0 == e.layerX) {
x = e.layerX;
y = e.layerY;
} else if (e.offsetX || 0 == e.offsetX) {
x = e.offsetX;
y = e.offsetY;
}
return {
x : x,
y : y
};
};
function on_mousedown(e) {
e.preventDefault();
e.stopPropagation();
canvas.addEventListener('mouseup', on_mouseup, false);
canvas.addEventListener('mousemove', on_mousemove, false);
canvas.addEventListener('touchend', on_mouseup, false);
canvas.addEventListener('touchmove', on_mousemove, false);
document.body.addEventListener('mouseup', on_mouseup, false);
document.body.addEventListener('touchend', on_mouseup, false);
empty = false;
var xy = get_coords(e);
context.beginPath();
pixels.push('moveStart');
context.moveTo(xy.x, xy.y);
pixels.push(xy.x, xy.y);
xyLast = xy;
};
function on_mousemove(e, finish) {
e.preventDefault();
e.stopPropagation();
var xy = get_coords(e);
var xyAdd = {
x : (xyLast.x + xy.x) / 2,
y : (xyLast.y + xy.y) / 2
};
if (calculate) {
var xLast = (xyAddLast.x + xyLast.x + xyAdd.x) / 3;
var yLast = (xyAddLast.y + xyLast.y + xyAdd.y) / 3;
pixels.push(xLast, yLast);
} else {
calculate = true;
}
context.quadraticCurveTo(xyLast.x, xyLast.y, xyAdd.x, xyAdd.y);
pixels.push(xyAdd.x, xyAdd.y);
context.stroke();
context.beginPath();
context.moveTo(xyAdd.x, xyAdd.y);
xyAddLast = xyAdd;
xyLast = xy;
};
function on_mouseup(e) {
remove_event_listeners();
disableSave = false;
context.stroke();
pixels.push('e');
calculate = false;
};
}
canvas.addEventListener('touchstart', on_mousedown, false);
canvas.addEventListener('mousedown', on_mousedown, false);
}
function signatureSave() {
var canvas = document.getElementById("newSignature");// save canvas image as data url (png format by default)
var dataURL = canvas.toDataURL("image/png");
document.getElementById("saveSignature").src = dataURL;
var url = img.src.replace(/^data:image\/[^;]/, 'data:application/octet-stream');
location.href = url;
};
function signatureClear() {
var canvas = document.getElementById("newSignature");
var context = canvas.getContext("2d");
context.clearRect(0, 0, canvas.width, canvas.height);
}
The problem is when i push button "Save signature", file saving with name "download". Every time i'm pushing this button, function saving file with new name: like "download (1)" What i want to do is set name by default, for example "test.png", and file become replaced by new file with the same name: "test.png".