web-dev-qa-db-ja.com

Fabricjsのパンとズーム

Fabricjsを使用してどのようにパンおよびズームできますか？私はメソッドzoomToPointとsetZoomを使用してみましたが、パンでは機能しません。別のズームポイントの使用を開始すると、問題が発生し始めます。

$('#zoomIn').click(function(){
    canvas.setZoom(canvas.getZoom() * 1.1 ) ;
}) ;

$('#zoomOut').click(function(){
    canvas.setZoom(canvas.getZoom() / 1.1 ) ;
}) ;

$('#goRight').click(function(){
    //Need to implement
}) ;

$('#goLeft').click(function(){
    //Need to implement
}) ;

http://jsfiddle.net/hdramos/ux16013L/

javascriptcanvasfabricjs
20
d0001

それを使ってそれを解決しました：

relativePan（）absolutePan（）

[更新]

$('#goRight').click(function(){
    var units = 10 ;
    var delta = new fabric.Point(units,0) ;
    canvas.relativePan(delta) ;
}) ;

$('#goLeft').click(function(){
    var units = 10 ;
    var delta = new fabric.Point(-units,0) ;
    canvas.relativePan(delta) ;
}) ;
$('#goUp').click(function(){
    var units = 10 ;
    var delta = new fabric.Point(0,-units) ;
    canvas.relativePan(delta) ;
}) ;

$('#goDown').click(function(){
    var units = 10 ;
    var delta = new fabric.Point(0,units) ;
    canvas.relativePan(delta) ;
});

http://jsfiddle.net/ux16013L/2/

19
d0001

私はそれがすでに答えられていることを知っていますが、私はマウスのパンニングをしなければならなかったので、受け入れられた答えのフィドルをそうするように調整しました。このようなことをしなければならない人のためにここに投稿します。これは主なアイデアです：

var panning = false;
canvas.on('mouse:up', function (e) {
    panning = false;
});

canvas.on('mouse:down', function (e) {
    panning = true;
});
canvas.on('mouse:move', function (e) {
    if (panning && e && e.e) {
        var units = 10;
        var delta = new fabric.Point(e.e.movementX, e.e.movementY);
        canvas.relativePan(delta);
    }
});

これがフィドルです： http://jsfiddle.net/gncabrera/hkee5L6d/5/

15
gncabrera

これがキャンバスズーム（マウスホイールを使用）とパン（左/上/右/下のキーまたはシフトキー+マウスの左下+マウスの移動を使用）の私の解決策です。

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>
7
Milan Hlinák

Githubで、fabric.js Canvasのパンとズームを使用した例があります。 https://sabatinomasala.github.io/fabric-clipping-demo/

パン動作を担当するコードは次のとおりです： https://github.com/SabatinoMasala/fabric-clipping-demo/blob/master/src/classes/Panning.js

これはfabric.Canvas.prototypeの単純な拡張機能であり、キャンバス上の「ドラッグモード」を次のように切り替えることができます。

canvas.toggleDragMode(true); // Start panning
canvas.toggleDragMode(false); // Stop panning

次のスニペットを見てください。ドキュメントはコード全体で利用できます。

const STATE_IDLE = 'idle';
const STATE_PANNING = 'panning';
fabric.Canvas.prototype.toggleDragMode = function(dragMode) {
  // Remember the previous X and Y coordinates for delta calculations
  let lastClientX;
  let lastClientY;
  // Keep track of the state
  let state = STATE_IDLE;
  // We're entering dragmode
  if (dragMode) {
    // Discard any active object
    this.discardActiveObject();
    // Set the cursor to 'move'
    this.defaultCursor = 'move';
    // Loop over all objects and disable events / selectable. We remember its value in a temp variable stored on each object
    this.forEachObject(function(object) {
      object.prevEvented = object.evented;
      object.prevSelectable = object.selectable;
      object.evented = false;
      object.selectable = false;
    });
    // Remove selection ability on the canvas
    this.selection = false;
    // When MouseUp fires, we set the state to idle
    this.on('mouse:up', function(e) {
      state = STATE_IDLE;
    });
    // When MouseDown fires, we set the state to panning
    this.on('mouse:down', (e) => {
      state = STATE_PANNING;
      lastClientX = e.e.clientX;
      lastClientY = e.e.clientY;
    });
    // When the mouse moves, and we're panning (mouse down), we continue
    this.on('mouse:move', (e) => {
      if (state === STATE_PANNING && e && e.e) {
        // let delta = new fabric.Point(e.e.movementX, e.e.movementY); // No Safari support for movementX and movementY
        // For cross-browser compatibility, I had to manually keep track of the delta

        // Calculate deltas
        let deltaX = 0;
        let deltaY = 0;
        if (lastClientX) {
          deltaX = e.e.clientX - lastClientX;
        }
        if (lastClientY) {
          deltaY = e.e.clientY - lastClientY;
        }
        // Update the last X and Y values
        lastClientX = e.e.clientX;
        lastClientY = e.e.clientY;

        let delta = new fabric.Point(deltaX, deltaY);
        this.relativePan(delta);
        this.trigger('moved');
      }
    });
  } else {
    // When we exit dragmode, we restore the previous values on all objects
    this.forEachObject(function(object) {
      object.evented = (object.prevEvented !== undefined) ? object.prevEvented : object.evented;
      object.selectable = (object.prevSelectable !== undefined) ? object.prevSelectable : object.selectable;
    });
    // Reset the cursor
    this.defaultCursor = 'default';
    // Remove the event listeners
    this.off('mouse:up');
    this.off('mouse:down');
    this.off('mouse:move');
    // Restore selection ability on the canvas
    this.selection = true;
  }
};

// Create the canvas

let canvas = new fabric.Canvas('fabric')
canvas.backgroundColor = '#f1f1f1';

// Add a couple of rects

let rect = new fabric.Rect({
  width: 100,
  height: 100,
  fill: '#f00'
});
canvas.add(rect)

rect = new fabric.Rect({
  width: 200,
  height: 200,
  top: 200,
  left: 200,
  fill: '#f00'
});
canvas.add(rect)

// Handle dragmode change

let dragMode = false;
$('#dragmode').change(_ => {
  dragMode = !dragMode;
  canvas.toggleDragMode(dragMode);
});
<div>
  <label for="dragmode">
    Enable panning
    <input type="checkbox" id="dragmode" name="dragmode" />
  </label>
</div>
<canvas width="300" height="300" id="fabric"></canvas>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/1.7.15/fabric.min.js"></script>
2
Sabatino

キャンバスを画面上でパンするだけで、要素の位置を変更しない場合は、 このソリューション を使用できます。

アイデアは、内部に拡張されたキャンバスを持つoverflow: hiddenのc​​ssを持つ固定サイズのコンテナーを持つことです。パンはキャンバスをコンテナ内で移動するため、ユーザーは消費されたキャンバスのさまざまな領域を毎回見ることができます。

0
Dudi