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coze-studio/frontend/packages/workflow/fabric-canvas/src/hooks/use-viewport.tsx
2025-07-31 23:15:48 +08:00

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TypeScript

/*
* Copyright 2025 coze-dev Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import { useCallback, useState } from 'react';
import { type Point, type TMat2D, type Canvas } from 'fabric';
import { setViewport, zoomToPoint } from '../utils';
import { type FabricSchema } from '../typings';
export const useViewport = ({
canvas,
schema,
minZoom,
maxZoom: maxZoom,
}: {
canvas?: Canvas;
schema: FabricSchema;
minZoom: number;
maxZoom: number;
}) => {
const [viewport, _setViewport] = useState<TMat2D>([1, 0, 0, 1, 0, 0]);
const setCanvasViewport = useCallback(
(vpt: TMat2D) => {
if (!canvas) {
return;
}
const _vpt: TMat2D = [...vpt];
// Limit viewport movement area: Cannot move out of canvas
if (_vpt[4] > 0) {
_vpt[4] = 0;
}
if (_vpt[4] < -schema.width * (_vpt[0] - 1)) {
_vpt[4] = -schema.width * (_vpt[0] - 1);
}
if (_vpt[5] > 0) {
_vpt[5] = 0;
}
if (_vpt[5] < -schema.height * (_vpt[0] - 1)) {
_vpt[5] = -schema.height * (_vpt[0] - 1);
}
setViewport({ canvas, vpt: _vpt });
_setViewport(_vpt);
canvas.fire('object:moving');
},
[canvas, schema, minZoom, maxZoom],
);
const _zoomToPoint = useCallback(
(point: Point, zoomLevel: number) => {
const vpt = zoomToPoint({
canvas,
point,
zoomLevel,
minZoom,
maxZoom,
});
setCanvasViewport(vpt);
},
[setCanvasViewport],
);
return {
setViewport: setCanvasViewport,
viewport,
zoomToPoint: _zoomToPoint,
};
};