Hier ist meine Lösung für Leinwand Zoom (mit Mausrad) und schwenken (mit links/oben/rechts/unten Tasten oder Umschalttaste + Maus nach links unten + Maus bewegen).
https://jsfiddle.net/milanhlinak/7s4w0uLy/8/
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript" src="lib/jquery-3.1.1.min.js"></script>
<script type="text/javascript" src="lib/fabric.min.js"></script>
</head>
<body>
<canvas id="canvas" style="border: 1px solid #cccccc"></canvas>
<script>
var Direction = {
LEFT: 0,
UP: 1,
RIGHT: 2,
DOWN: 3
};
var zoomLevel = 0;
var zoomLevelMin = 0;
var zoomLevelMax = 3;
var shiftKeyDown = false;
var mouseDownPoint = null;
var canvas = new fabric.Canvas('canvas', {
width: 500,
height: 500,
selectionKey: 'ctrlKey'
});
canvas.add(new fabric.Rect({
left: 100,
top: 100,
width: 50,
height: 50,
fill: '#faa'
}));
canvas.add(new fabric.Rect({
left: 300,
top: 300,
width: 50,
height: 50,
fill: '#afa'
}));
canvas.on('mouse:down', function (options) {
var pointer = canvas.getPointer(options.e, true);
mouseDownPoint = new fabric.Point(pointer.x, pointer.y);
});
canvas.on('mouse:up', function (options) {
mouseDownPoint = null;
});
canvas.on('mouse:move', function (options) {
if (shiftKeyDown && mouseDownPoint) {
var pointer = canvas.getPointer(options.e, true);
var mouseMovePoint = new fabric.Point(pointer.x, pointer.y);
canvas.relativePan(mouseMovePoint.subtract(mouseDownPoint));
mouseDownPoint = mouseMovePoint;
keepPositionInBounds(canvas);
}
});
fabric.util.addListener(document.body, 'keydown', function (options) {
if (options.repeat) {
return;
}
var key = options.which || options.keyCode; // key detection
if (key == 16) { // handle Shift key
canvas.defaultCursor = 'move';
canvas.selection = false;
shiftKeyDown = true;
} else if (key === 37) { // handle Left key
move(Direction.LEFT);
} else if (key === 38) { // handle Up key
move(Direction.UP);
} else if (key === 39) { // handle Right key
move(Direction.RIGHT);
} else if (key === 40) { // handle Down key
move(Direction.DOWN);
}
});
fabric.util.addListener(document.body, 'keyup', function (options) {
var key = options.which || options.keyCode; // key detection
if (key == 16) { // handle Shift key
canvas.defaultCursor = 'default';
canvas.selection = true;
shiftKeyDown = false;
}
});
jQuery('.canvas-container').on('mousewheel', function (options) {
var delta = options.originalEvent.wheelDelta;
if (delta != 0) {
var pointer = canvas.getPointer(options.e, true);
var point = new fabric.Point(pointer.x, pointer.y);
if (delta > 0) {
zoomIn(point);
} else if (delta < 0) {
zoomOut(point);
}
}
});
function move(direction) {
switch (direction) {
case Direction.LEFT:
canvas.relativePan(new fabric.Point(-10 * canvas.getZoom(), 0));
break;
case Direction.UP:
canvas.relativePan(new fabric.Point(0, -10 * canvas.getZoom()));
break;
case Direction.RIGHT:
canvas.relativePan(new fabric.Point(10 * canvas.getZoom(), 0));
break;
case Direction.DOWN:
canvas.relativePan(new fabric.Point(0, 10 * canvas.getZoom()));
break;
}
keepPositionInBounds(canvas);
}
function zoomIn(point) {
if (zoomLevel < zoomLevelMax) {
zoomLevel++;
canvas.zoomToPoint(point, Math.pow(2, zoomLevel));
keepPositionInBounds(canvas);
}
}
function zoomOut(point) {
if (zoomLevel > zoomLevelMin) {
zoomLevel--;
canvas.zoomToPoint(point, Math.pow(2, zoomLevel));
keepPositionInBounds(canvas);
}
}
function keepPositionInBounds() {
var zoom = canvas.getZoom();
var xMin = (2 - zoom) * canvas.getWidth()/2;
var xMax = zoom * canvas.getWidth()/2;
var yMin = (2 - zoom) * canvas.getHeight()/2;
var yMax = zoom * canvas.getHeight()/2;
var point = new fabric.Point(canvas.getWidth()/2, canvas.getHeight()/2);
var center = fabric.util.transformPoint(point, canvas.viewportTransform);
var clampedCenterX = clamp(center.x, xMin, xMax);
var clampedCenterY = clamp(center.y, yMin, yMax);
var diffX = clampedCenterX - center.x;
var diffY = clampedCenterY - center.y;
if (diffX != 0 || diffY != 0) {
canvas.relativePan(new fabric.Point(diffX, diffY));
}
}
function clamp(value, min, max) {
return Math.max(min, Math.min(value, max));
}
</script>
</body>
</html>
Können Sie das näher erläutern? Auf was mache ich die Anpassung? – d0001