Pincez pour zoomer à l'aide de Hammer.js
J'essaie d'implémenter pincer pour zoomer en utilisant hammer.js
Voici mon HTML-
<script src="//cdnjs.cloudflare.com/ajax/libs/hammer.js/1.0.5/hammer.min.js"></script>
<div id="pinchzoom">
<div>
<img id="rect" src="http://blog.gettyimages.com/wp-content/uploads/2013/01/Siberian-Tiger-Running-Through-Snow-Tom-Brakefield-Getty-Images-200353826-001.jpg" width="2835" height="4289" ondragstart="return false" alt="" />
</div>
</div>
Voici mon SCRIPT
var hammertime = Hammer(document.getElementById('pinchzoom'), {
transform_always_block: true,
transform_min_scale: 1,
drag_block_horizontal: false,
drag_block_vertical: false,
drag_min_distance: 0
});
var rect = document.getElementById('rect');
var posX=0, posY=0,
scale=1, last_scale,
rotation= 1, last_rotation;
hammertime.on('touch drag transform', function(ev) {
switch(ev.type) {
case 'touch':
last_scale = scale;
last_rotation = rotation;
break;
case 'drag':
posX = ev.gesture.deltaX;
posY = ev.gesture.deltaY;
break;
case 'transform':
rotation = last_rotation + ev.gesture.rotation;
scale = Math.max(1, Math.min(last_scale * ev.gesture.scale, 10));
break;
}
// transform!
var transform =
//"translate3d("+posX+"px,"+posY+"px, 0) " +
"scale3d("+scale+","+scale+", 0) ";
rect.style.transform = transform;
rect.style.oTransform = transform;
rect.style.msTransform = transform;
rect.style.mozTransform = transform;
rect.style.webkitTransform = transform;
});
Cela fonctionne bien mais je ne suis pas en mesure de faire défiler l'image. Sur transform3d sans commentaire, cela fonctionne mais l'image perd sa position lors du glissement. Je ne peux pas utiliser jQuery.
Pour hammer.js 2.0+, j'ai pris la réponse @DGS et je l'ai modifiée pour l'adapter à ce que je faisais avec cordova et intel-xdk donc c'est JS pur et hammer.js 2.0 pour webkit .
Mon implémentation vous permet de zoomer et de faire glisser en même temps, non indépendants les uns des autres comme ci-dessus, et offre une sensation plus native. Il implémente également le double tap pour effectuer un zoom avant ( et un zoom arrière ). Je l'ai réglé pour zoomer entre .999 et 4, mais vous pouvez faire ce que vous voulez en changeant simplement ces valeurs. Donc, si vous copiez et collez simplement cela, il fera probablement ce que vous attendez ( sur webkit).
Merci à Eight Media et @DGS pour m'avoir aidé! N'hésitez pas à l'améliorer SO.
function hammerIt(Elm) {
hammertime = new Hammer(Elm, {});
hammertime.get('pinch').set({
enable: true
});
var posX = 0,
posY = 0,
scale = 1,
last_scale = 1,
last_posX = 0,
last_posY = 0,
max_pos_x = 0,
max_pos_y = 0,
transform = "",
el = Elm;
hammertime.on('doubletap pan pinch panend pinchend', function(ev) {
if (ev.type == "doubletap") {
transform =
"translate3d(0, 0, 0) " +
"scale3d(2, 2, 1) ";
scale = 2;
last_scale = 2;
try {
if (window.getComputedStyle(el, null).getPropertyValue('-webkit-transform').toString() != "matrix(1, 0, 0, 1, 0, 0)") {
transform =
"translate3d(0, 0, 0) " +
"scale3d(1, 1, 1) ";
scale = 1;
last_scale = 1;
}
} catch (err) {}
el.style.webkitTransform = transform;
transform = "";
}
//pan
if (scale != 1) {
posX = last_posX + ev.deltaX;
posY = last_posY + ev.deltaY;
max_pos_x = Math.ceil((scale - 1) * el.clientWidth / 2);
max_pos_y = Math.ceil((scale - 1) * el.clientHeight / 2);
if (posX > max_pos_x) {
posX = max_pos_x;
}
if (posX < -max_pos_x) {
posX = -max_pos_x;
}
if (posY > max_pos_y) {
posY = max_pos_y;
}
if (posY < -max_pos_y) {
posY = -max_pos_y;
}
}
//pinch
if (ev.type == "pinch") {
scale = Math.max(.999, Math.min(last_scale * (ev.scale), 4));
}
if(ev.type == "pinchend"){last_scale = scale;}
//panend
if(ev.type == "panend"){
last_posX = posX < max_pos_x ? posX : max_pos_x;
last_posY = posY < max_pos_y ? posY : max_pos_y;
}
if (scale != 1) {
transform =
"translate3d(" + posX + "px," + posY + "px, 0) " +
"scale3d(" + scale + ", " + scale + ", 1)";
}
if (transform) {
el.style.webkitTransform = transform;
}
});
}
Pour l'implémenter, il suffit de l'appeler avec hammerIt (document.getElementById ("imagid")); après le chargement de l'élément. Vous pouvez appeler cela sur autant d'éléments que vous le souhaitez.
À votre santé!
Ajouter des variables last_posX et last_posY pour tenir compte du changement de position lorsque vous avez traduit. mettez-les à jour sur dragend afin que la prochaine fois qu'un événement de glisser soit capturé, il tienne compte de la fin du dernier glisser
var posX=0, posY=0,
scale=1, last_scale,
last_posX=0, last_posY=0,
max_pos_x=0, max_pos_y=0;
hammertime.on('touch drag transform dragend', function(ev) {
switch(ev.type) {
case 'touch':
last_scale = scale;
break;
case 'drag':
if(scale != 1){
posX = last_posX + ev.gesture.deltaX;
posY = last_posY + ev.gesture.deltaY;
if(posX > max_pos_x){
posX = max_pos_x;
}
if(posX < -max_pos_x){
posX = -max_pos_x;
}
if(posY > max_pos_y){
posY = max_pos_y;
}
if(posY < -max_pos_y){
posY = -max_pos_y;
}
}else{
posX = 0;
posY = 0;
saved_posX = 0;
saved_posY = 0;
}
break;
case 'transform':
scale = Math.max(1, Math.min(last_scale * ev.gesture.scale, 10));
max_pos_x = Math.ceil((scale - 1) * rect.clientWidth / 2);
max_pos_y = Math.ceil((scale - 1) * rect.clientHeight / 2);
if(posX > max_pos_x){
posX = max_pos_x;
}
if(posX < -max_pos_x){
posX = -max_pos_x;
}
if(posY > max_pos_y){
posY = max_pos_y;
}
if(posY < -max_pos_y){
posY = -max_pos_y;
}
break;
case 'dragend':
last_posX = posX < max_pos_x ? posX: max_pos_x;
last_posY = posY < max_pos_y ? posY: max_pos_y;
break;
}
// transform!
var transform =
"translate3d(0, 0, 0) " +
"scale3d(1, 1, 0) ";
if(scale != 1){
transform =
"translate3d("+posX+"px,"+posY+"px, 0) " +
"scale3d("+scale+","+scale+", 0) ";
}
rect.style.transform = transform;
rect.style.oTransform = transform;
rect.style.msTransform = transform;
rect.style.mozTransform = transform;
rect.style.webkitTransform = transform;
});
Je n'étais pas vraiment satisfait des solutions alors j'en ai créé une aussi.
Vous pouvez jouer avec lui sur https://bl.ocks.org/stephanbogner/06c3e0d3a1c8fcca61b5345e1af80798
Le code est plus complexe, mais il se comporte comme sur iOS (testé sur iPad et iPhone):
- Vous appuyez deux fois sur l'image et elle zoome à cet endroit exact
- Pendant que vous pincez, le centre du zoom est entre vos doigts et vous pouvez faire glisser tout en pinçant
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>HammerJS Pinch Zoom and Drag</title>
<style type="text/css">
body{
margin: 0;
padding: 0;
}
#dragWrapper{
margin: 40px;
background: whitesmoke;
width: calc(100vw - 80px);
height: calc(100vh - 80px);
position: relative;
}
#drag {
touch-action: auto;
height: 300px;
width: 200px;
position: absolute;
left: 0;
top: 0;
background-image: url('https://upload.wikimedia.org/wikipedia/commons/thumb/4/4a/Bergelut_dengan_asap_nan_beracun.jpg/318px-Bergelut_dengan_asap_nan_beracun.jpg');
background-size: cover;
}
</style>
</head>
<body>
<div id="dragWrapper">
<div id="drag"></div>
</div>
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/hammer.js/2.0.8/hammer.min.js"></script>
<script type="text/javascript">
var element = document.getElementById('drag')
var hammertime = new Hammer(element, {});
hammertime.get('pinch').set({ enable: true });
hammertime.get('pan').set({ threshold: 0 });
var fixHammerjsDeltaIssue = undefined;
var pinchStart = { x: undefined, y: undefined }
var lastEvent = undefined;
var originalSize = {
width: 200,
height: 300
}
var current = {
x: 0,
y: 0,
z: 1,
zooming: false,
width: originalSize.width * 1,
height: originalSize.height * 1,
}
var last = {
x: current.x,
y: current.y,
z: current.z
}
function getRelativePosition(element, point, originalSize, scale) {
var domCoords = getCoords(element);
var elementX = point.x - domCoords.x;
var elementY = point.y - domCoords.y;
var relativeX = elementX / (originalSize.width * scale / 2) - 1;
var relativeY = elementY / (originalSize.height * scale / 2) - 1;
return { x: relativeX, y: relativeY }
}
function getCoords(elem) { // crossbrowser version
var box = elem.getBoundingClientRect();
var body = document.body;
var docEl = document.documentElement;
var scrollTop = window.pageYOffset || docEl.scrollTop || body.scrollTop;
var scrollLeft = window.pageXOffset || docEl.scrollLeft || body.scrollLeft;
var clientTop = docEl.clientTop || body.clientTop || 0;
var clientLeft = docEl.clientLeft || body.clientLeft || 0;
var top = box.top + scrollTop - clientTop;
var left = box.left + scrollLeft - clientLeft;
return { x: Math.round(left), y: Math.round(top) };
}
function scaleFrom(zoomOrigin, currentScale, newScale) {
var currentShift = getCoordinateShiftDueToScale(originalSize, currentScale);
var newShift = getCoordinateShiftDueToScale(originalSize, newScale)
var zoomDistance = newScale - currentScale
var shift = {
x: currentShift.x - newShift.x,
y: currentShift.y - newShift.y,
}
var output = {
x: zoomOrigin.x * shift.x,
y: zoomOrigin.y * shift.y,
z: zoomDistance
}
return output
}
function getCoordinateShiftDueToScale(size, scale){
var newWidth = scale * size.width;
var newHeight = scale * size.height;
var dx = (newWidth - size.width) / 2
var dy = (newHeight - size.height) / 2
return {
x: dx,
y: dy
}
}
hammertime.on('doubletap', function(e) {
var scaleFactor = 1;
if (current.zooming === false) {
current.zooming = true;
} else {
current.zooming = false;
scaleFactor = -scaleFactor;
}
element.style.transition = "0.3s";
setTimeout(function() {
element.style.transition = "none";
}, 300)
var zoomOrigin = getRelativePosition(element, { x: e.center.x, y: e.center.y }, originalSize, current.z);
var d = scaleFrom(zoomOrigin, current.z, current.z + scaleFactor)
current.x += d.x;
current.y += d.y;
current.z += d.z;
last.x = current.x;
last.y = current.y;
last.z = current.z;
update();
})
hammertime.on('pan', function(e) {
if (lastEvent !== 'pan') {
fixHammerjsDeltaIssue = {
x: e.deltaX,
y: e.deltaY
}
}
current.x = last.x + e.deltaX - fixHammerjsDeltaIssue.x;
current.y = last.y + e.deltaY - fixHammerjsDeltaIssue.y;
lastEvent = 'pan';
update();
})
hammertime.on('pinch', function(e) {
var d = scaleFrom(pinchZoomOrigin, last.z, last.z * e.scale)
current.x = d.x + last.x + e.deltaX;
current.y = d.y + last.y + e.deltaY;
current.z = d.z + last.z;
lastEvent = 'pinch';
update();
})
var pinchZoomOrigin = undefined;
hammertime.on('pinchstart', function(e) {
pinchStart.x = e.center.x;
pinchStart.y = e.center.y;
pinchZoomOrigin = getRelativePosition(element, { x: pinchStart.x, y: pinchStart.y }, originalSize, current.z);
lastEvent = 'pinchstart';
})
hammertime.on('panend', function(e) {
last.x = current.x;
last.y = current.y;
lastEvent = 'panend';
})
hammertime.on('pinchend', function(e) {
last.x = current.x;
last.y = current.y;
last.z = current.z;
lastEvent = 'pinchend';
})
function update() {
current.height = originalSize.height * current.z;
current.width = originalSize.width * current.z;
element.style.transform = "translate3d(" + current.x + "px, " + current.y + "px, 0) scale(" + current.z + ")";
}
</script>
</body>
</html>
Découvrez Pinch Zoom and Pan avec HammerJS demo . Cet exemple a été testé sur Android, iOS et Windows Phone.
Vous pouvez trouver le code source sur Pinch Zoom and Pan with HammerJS .
Pour votre commodité, voici le code source:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport"
content="user-scalable=no, width=device-width, initial-scale=1, maximum-scale=1">
<title>Pinch Zoom</title>
</head>
<body>
<div>
<div style="height:150px;background-color:#eeeeee">
Ignore this area. Space is needed to test on the iPhone simulator as pinch simulation on the
iPhone simulator requires the target to be near the middle of the screen and we only respect
touch events in the image area. This space is not needed in production.
</div>
<style>
.pinch-zoom-container {
overflow: hidden;
height: 300px;
}
.pinch-zoom-image {
width: 100%;
}
</style>
<script src="https://hammerjs.github.io/dist/hammer.js"></script>
<script>
var MIN_SCALE = 1; // 1=scaling when first loaded
var MAX_SCALE = 64;
// HammerJS fires "pinch" and "pan" events that are cumulative in nature and not
// deltas. Therefore, we need to store the "last" values of scale, x and y so that we can
// adjust the UI accordingly. It isn't until the "pinchend" and "panend" events are received
// that we can set the "last" values.
// Our "raw" coordinates are not scaled. This allows us to only have to modify our stored
// coordinates when the UI is updated. It also simplifies our calculations as these
// coordinates are without respect to the current scale.
var imgWidth = null;
var imgHeight = null;
var viewportWidth = null;
var viewportHeight = null;
var scale = null;
var lastScale = null;
var container = null;
var img = null;
var x = 0;
var lastX = 0;
var y = 0;
var lastY = 0;
var pinchCenter = null;
// We need to disable the following event handlers so that the browser doesn't try to
// automatically handle our image drag gestures.
var disableImgEventHandlers = function () {
var events = ['onclick', 'onmousedown', 'onmousemove', 'onmouseout', 'onmouseover',
'onmouseup', 'ondblclick', 'onfocus', 'onblur'];
events.forEach(function (event) {
img[event] = function () {
return false;
};
});
};
// Traverse the DOM to calculate the absolute position of an element
var absolutePosition = function (el) {
var x = 0,
y = 0;
while (el !== null) {
x += el.offsetLeft;
y += el.offsetTop;
el = el.offsetParent;
}
return { x: x, y: y };
};
var restrictScale = function (scale) {
if (scale < MIN_SCALE) {
scale = MIN_SCALE;
} else if (scale > MAX_SCALE) {
scale = MAX_SCALE;
}
return scale;
};
var restrictRawPos = function (pos, viewportDim, imgDim) {
if (pos < viewportDim/scale - imgDim) { // too far left/up?
pos = viewportDim/scale - imgDim;
} else if (pos > 0) { // too far right/down?
pos = 0;
}
return pos;
};
var updateLastPos = function (deltaX, deltaY) {
lastX = x;
lastY = y;
};
var translate = function (deltaX, deltaY) {
// We restrict to the min of the viewport width/height or current width/height as the
// current width/height may be smaller than the viewport width/height
var newX = restrictRawPos(lastX + deltaX/scale,
Math.min(viewportWidth, curWidth), imgWidth);
x = newX;
img.style.marginLeft = Math.ceil(newX*scale) + 'px';
var newY = restrictRawPos(lastY + deltaY/scale,
Math.min(viewportHeight, curHeight), imgHeight);
y = newY;
img.style.marginTop = Math.ceil(newY*scale) + 'px';
};
var zoom = function (scaleBy) {
scale = restrictScale(lastScale*scaleBy);
curWidth = imgWidth*scale;
curHeight = imgHeight*scale;
img.style.width = Math.ceil(curWidth) + 'px';
img.style.height = Math.ceil(curHeight) + 'px';
// Adjust margins to make sure that we aren't out of bounds
translate(0, 0);
};
var rawCenter = function (e) {
var pos = absolutePosition(container);
// We need to account for the scroll position
var scrollLeft = window.pageXOffset ? window.pageXOffset : document.body.scrollLeft;
var scrollTop = window.pageYOffset ? window.pageYOffset : document.body.scrollTop;
var zoomX = -x + (e.center.x - pos.x + scrollLeft)/scale;
var zoomY = -y + (e.center.y - pos.y + scrollTop)/scale;
return { x: zoomX, y: zoomY };
};
var updateLastScale = function () {
lastScale = scale;
};
var zoomAround = function (scaleBy, rawZoomX, rawZoomY, doNotUpdateLast) {
// Zoom
zoom(scaleBy);
// New raw center of viewport
var rawCenterX = -x + Math.min(viewportWidth, curWidth)/2/scale;
var rawCenterY = -y + Math.min(viewportHeight, curHeight)/2/scale;
// Delta
var deltaX = (rawCenterX - rawZoomX)*scale;
var deltaY = (rawCenterY - rawZoomY)*scale;
// Translate back to zoom center
translate(deltaX, deltaY);
if (!doNotUpdateLast) {
updateLastScale();
updateLastPos();
}
};
var zoomCenter = function (scaleBy) {
// Center of viewport
var zoomX = -x + Math.min(viewportWidth, curWidth)/2/scale;
var zoomY = -y + Math.min(viewportHeight, curHeight)/2/scale;
zoomAround(scaleBy, zoomX, zoomY);
};
var zoomIn = function () {
zoomCenter(2);
};
var zoomOut = function () {
zoomCenter(1/2);
};
var onLoad = function () {
img = document.getElementById('pinch-zoom-image-id');
container = img.parentElement;
disableImgEventHandlers();
imgWidth = img.width;
imgHeight = img.height;
viewportWidth = img.offsetWidth;
scale = viewportWidth/imgWidth;
lastScale = scale;
viewportHeight = img.parentElement.offsetHeight;
curWidth = imgWidth*scale;
curHeight = imgHeight*scale;
var hammer = new Hammer(container, {
domEvents: true
});
hammer.get('pinch').set({
enable: true
});
hammer.on('pan', function (e) {
translate(e.deltaX, e.deltaY);
});
hammer.on('panend', function (e) {
updateLastPos();
});
hammer.on('pinch', function (e) {
// We only calculate the pinch center on the first pinch event as we want the center to
// stay consistent during the entire pinch
if (pinchCenter === null) {
pinchCenter = rawCenter(e);
var offsetX = pinchCenter.x*scale - (-x*scale + Math.min(viewportWidth, curWidth)/2);
var offsetY = pinchCenter.y*scale - (-y*scale + Math.min(viewportHeight, curHeight)/2);
pinchCenterOffset = { x: offsetX, y: offsetY };
}
// When the user pinch zooms, she/he expects the pinch center to remain in the same
// relative location of the screen. To achieve this, the raw zoom center is calculated by
// first storing the pinch center and the scaled offset to the current center of the
// image. The new scale is then used to calculate the zoom center. This has the effect of
// actually translating the zoom center on each pinch zoom event.
var newScale = restrictScale(scale*e.scale);
var zoomX = pinchCenter.x*newScale - pinchCenterOffset.x;
var zoomY = pinchCenter.y*newScale - pinchCenterOffset.y;
var zoomCenter = { x: zoomX/newScale, y: zoomY/newScale };
zoomAround(e.scale, zoomCenter.x, zoomCenter.y, true);
});
hammer.on('pinchend', function (e) {
updateLastScale();
updateLastPos();
pinchCenter = null;
});
hammer.on('doubletap', function (e) {
var c = rawCenter(e);
zoomAround(2, c.x, c.y);
});
};
</script>
<button onclick="zoomIn()">Zoom In</button>
<button onclick="zoomOut()">Zoom Out</button>
<div class="pinch-zoom-container">
<img id="pinch-zoom-image-id" class="pinch-zoom-image" onload="onLoad()"
src="https://hammerjs.github.io/assets/img/pano-1.jpg">
</div>
</div>
</body>
</html>(BTW, Il y a beaucoup de bonnes informations ci-dessus, mais je n'ai pu faire fonctionner aucun des exemples et il y a quelques détails subtils que je voulais implémenter, comme la prise en compte du centre de zoom).