到目前为止，我已经使用http://www.html5canvastutorials.com/labs/html5-canvas-drag-and-drop-resize-and-invert-images/上的示例作为调整大小功能的基础。然而，在新版本的 kineticjs (4.3.0+) 中引入了一个用于拖动的特殊层。这也需要更新上面的脚本。我已经更新了上面的脚本，这导致了下面的脚本。主要区别是我直接调用拖动的锚点而不是通过组访问它（它曾经在同一层上）。该脚本运行良好，但现在有延迟。锚点移动得更慢，然后图像调整大小。任何人都知道如何解决这个问题？提前致谢。
function update(group, activeAnchor) {
var topLeft = group.get(".topLeft")[0];
var topRight = group.get(".topRight")[0];
var bottomRight = group.get(".bottomRight")[0];
var bottomLeft = group.get(".bottomLeft")[0];
var image = group.get(".image")[0];
switch (activeAnchor.getName()) {
case "topLeft":
var topLeft = activeAnchor;
topRight.attrs.y = activeAnchor.attrs.y;
bottomLeft.attrs.x = activeAnchor.attrs.x;
break;
case "topRight":
var topRight = activeAnchor;
topLeft.attrs.y = activeAnchor.attrs.y;
bottomRight.attrs.x = activeAnchor.attrs.x;
break;
case "bottomRight":
var bottomRight = activeAnchor;
bottomLeft.attrs.y = activeAnchor.attrs.y;
topRight.attrs.x = activeAnchor.attrs.x;
break;
case "bottomLeft":
var bottomLeft = activeAnchor;
bottomRight.attrs.y = activeAnchor.attrs.y;
topLeft.attrs.x = activeAnchor.attrs.x;
break;
}
image.setPosition(topLeft.attrs.x, topLeft.attrs.y);
var height = bottomLeft.attrs.y - topLeft.attrs.y;
var width = image.getWidth()*height/image.getHeight();
topRight.attrs.x = topLeft.attrs.x + width;
topRight.attrs.y = topLeft.attrs.y;
bottomRight.attrs.x = topLeft.attrs.x + width;
bottomRight.attrs.y = topLeft.attrs.y + height;
if(width && height) {
image.setSize(width, height);
}
}
function addAnchor(group, x, y, name) {
var stage = group.getStage();
var layer = group.getLayer();
var anchor = new Kinetic.Circle({
x: x,
y: y,
stroke: "#666",
fill: "#ddd",
strokeWidth: 2,
radius: 8,
name: name,
draggable: true
});
anchor.on("dragmove", function() {
update(group, this);
layer.draw();
});
anchor.on("mousedown touchstart", function() {
group.setDraggable(false);
this.moveToTop();
});
anchor.on("dragend", function() {
group.setDraggable(true);
layer.draw();
});
// add hover styling
anchor.on("mouseover", function() {
var layer = this.getLayer();
document.body.style.cursor = "pointer";
this.setStrokeWidth(4);
layer.draw();
});
anchor.on("mouseout", function() {
var layer = this.getLayer();
document.body.style.cursor = "default";
this.setStrokeWidth(2);
layer.draw();
});
group.add(anchor);
}
function loadImages(sources, callback) {
var images = {};
var loadedImages = 0;
var numImages = 0;
for(var src in sources) {
numImages++;
}
for(var src in sources) {
images[src] = new Image();
images[src].onload = function() {
if(++loadedImages >= numImages) {
callback(images);
}
};
images[src].src = sources[src];
}
}
function initStage(images) {
var stage = new Kinetic.Stage({
container: "container",
width: 578,
height: 400
});
var yodaGroup = new Kinetic.Group({
x: 100,
y: 110,
draggable: true
});
var layer = new Kinetic.Layer();
/*
* go ahead and add the groups
* to the layer and the layer to the
* stage so that the groups have knowledge
* of its layer and stage
*/
layer.add(yodaGroup);
stage.add(layer);
// darth vader
// yoda
var yodaImg = new Kinetic.Rect({
x: 0,
y: 0,
fill: 'blue',
width: 93,
height: 104,
name: "image"
});
yodaGroup.add(yodaImg);
addAnchor(yodaGroup, 0, 0, "topLeft");
addAnchor(yodaGroup, 93, 0, "topRight");
addAnchor(yodaGroup, 93, 104, "bottomRight");
addAnchor(yodaGroup, 0, 104, "bottomLeft");
yodaGroup.on("dragstart", function() {
this.moveToTop();
});
stage.draw();
}
$(document).ready(function(){
var sources = {
darthVader: "http://www.html5canvastutorials.com/demos/assets/darth-vader.jpg",
yoda: "http://www.html5canvastutorials.com/demos/assets/yoda.jpg"
};
loadImages(sources, initStage);