Files
lightweight-charts-python/src/trend-line/trend-line.ts
2024-03-30 15:38:34 +00:00

110 lines
3.2 KiB
TypeScript

import {
MouseEventParams,
} from 'lightweight-charts';
import { TrendLinePaneView } from './pane-view';
import { Point } from '../drawing/data-source';
import { Drawing, InteractionState } from '../drawing/drawing';
import { DrawingOptions } from '../drawing/options';
import { TwoPointDrawing } from '../drawing/two-point-drawing';
export class TrendLine extends TwoPointDrawing {
_type = "TrendLine"
constructor(
p1: Point,
p2: Point,
options?: Partial<DrawingOptions>
) {
super(p1, p2, options)
this._paneViews = [new TrendLinePaneView(this)];
}
_moveToState(state: InteractionState) {
switch(state) {
case InteractionState.NONE:
document.body.style.cursor = "default";
this._options.showCircles = false;
this.requestUpdate();
this._unsubscribe("mousedown", this._handleMouseDownInteraction);
break;
case InteractionState.HOVERING:
document.body.style.cursor = "pointer";
this._options.showCircles = true;
this.requestUpdate();
this._subscribe("mousedown", this._handleMouseDownInteraction);
this._unsubscribe("mouseup", this._handleMouseDownInteraction);
this.chart.applyOptions({handleScroll: true});
break;
case InteractionState.DRAGGINGP1:
case InteractionState.DRAGGINGP2:
case InteractionState.DRAGGING:
document.body.style.cursor = "grabbing";
this._subscribe("mouseup", this._handleMouseUpInteraction);
this.chart.applyOptions({handleScroll: false});
break;
}
this._state = state;
}
_onDrag(diff: any) {
if (this._state == InteractionState.DRAGGING || this._state == InteractionState.DRAGGINGP1) {
Drawing._addDiffToPoint(this._p1, diff.time, diff.logical, diff.price);
}
if (this._state == InteractionState.DRAGGING || this._state == InteractionState.DRAGGINGP2) {
Drawing._addDiffToPoint(this._p2, diff.time, diff.logical, diff.price);
}
}
protected _onMouseDown() {
this._startDragPoint = null;
const hoverPoint = this._latestHoverPoint;
if (!hoverPoint) return;
const p1 = this._paneViews[0]._p1;
const p2 = this._paneViews[0]._p2;
if (!p1.x || !p2.x || !p1.y || !p2.y) return this._moveToState(InteractionState.DRAGGING);
const tolerance = 10;
if (Math.abs(hoverPoint.x-p1.x) < tolerance && Math.abs(hoverPoint.y-p1.y) < tolerance) {
this._moveToState(InteractionState.DRAGGINGP1)
}
else if (Math.abs(hoverPoint.x-p2.x) < tolerance && Math.abs(hoverPoint.y-p2.y) < tolerance) {
this._moveToState(InteractionState.DRAGGINGP2)
}
else {
this._moveToState(InteractionState.DRAGGING);
}
}
protected _mouseIsOverDrawing(param: MouseEventParams, tolerance = 4) {
if (!param.point) return false;;
const x1 = this._paneViews[0]._p1.x;
const y1 = this._paneViews[0]._p1.y;
const x2 = this._paneViews[0]._p2.x;
const y2 = this._paneViews[0]._p2.y;
if (!x1 || !x2 || !y1 || !y2 ) return false;
const mouseX = param.point.x;
const mouseY = param.point.y;
if (mouseX <= Math.min(x1, x2) - tolerance ||
mouseX >= Math.max(x1, x2) + tolerance) {
return false;
}
const distance = Math.abs((y2 - y1) * mouseX - (x2 - x1) * mouseY + x2 * y1 - y2 * x1
) / Math.sqrt((y2 - y1) ** 2 + (x2 - x1) ** 2);
return distance <= tolerance
}
}