basant307/AI_Governance_Project

1import {dispatch} from "d3-dispatch";2import {select, pointer} from "d3-selection";3import nodrag, {yesdrag} from "./nodrag.js";4import noevent, {nonpassive, nonpassivecapture, nopropagation} from "./noevent.js";5import constant from "./constant.js";6import DragEvent from "./event.js";7 8// Ignore right-click, since that should open the context menu.9function defaultFilter(event) {10  return !event.ctrlKey && !event.button;11}12 13function defaultContainer() {14  return this.parentNode;15}16 17function defaultSubject(event, d) {18  return d == null ? {x: event.x, y: event.y} : d;19}20 21function defaultTouchable() {22  return navigator.maxTouchPoints || ("ontouchstart" in this);23}24 25export default function() {26  var filter = defaultFilter,27      container = defaultContainer,28      subject = defaultSubject,29      touchable = defaultTouchable,30      gestures = {},31      listeners = dispatch("start", "drag", "end"),32      active = 0,33      mousedownx,34      mousedowny,35      mousemoving,36      touchending,37      clickDistance2 = 0;38 39  function drag(selection) {40    selection41        .on("mousedown.drag", mousedowned)42      .filter(touchable)43        .on("touchstart.drag", touchstarted)44        .on("touchmove.drag", touchmoved, nonpassive)45        .on("touchend.drag touchcancel.drag", touchended)46        .style("touch-action", "none")47        .style("-webkit-tap-highlight-color", "rgba(0,0,0,0)");48  }49 50  function mousedowned(event, d) {51    if (touchending || !filter.call(this, event, d)) return;52    var gesture = beforestart(this, container.call(this, event, d), event, d, "mouse");53    if (!gesture) return;54    select(event.view)55      .on("mousemove.drag", mousemoved, nonpassivecapture)56      .on("mouseup.drag", mouseupped, nonpassivecapture);57    nodrag(event.view);58    nopropagation(event);59    mousemoving = false;60    mousedownx = event.clientX;61    mousedowny = event.clientY;62    gesture("start", event);63  }64 65  function mousemoved(event) {66    noevent(event);67    if (!mousemoving) {68      var dx = event.clientX - mousedownx, dy = event.clientY - mousedowny;69      mousemoving = dx * dx + dy * dy > clickDistance2;70    }71    gestures.mouse("drag", event);72  }73 74  function mouseupped(event) {75    select(event.view).on("mousemove.drag mouseup.drag", null);76    yesdrag(event.view, mousemoving);77    noevent(event);78    gestures.mouse("end", event);79  }80 81  function touchstarted(event, d) {82    if (!filter.call(this, event, d)) return;83    var touches = event.changedTouches,84        c = container.call(this, event, d),85        n = touches.length, i, gesture;86 87    for (i = 0; i < n; ++i) {88      if (gesture = beforestart(this, c, event, d, touches[i].identifier, touches[i])) {89        nopropagation(event);90        gesture("start", event, touches[i]);91      }92    }93  }94 95  function touchmoved(event) {96    var touches = event.changedTouches,97        n = touches.length, i, gesture;98 99    for (i = 0; i < n; ++i) {100      if (gesture = gestures[touches[i].identifier]) {101        noevent(event);102        gesture("drag", event, touches[i]);103      }104    }105  }106 107  function touchended(event) {108    var touches = event.changedTouches,109        n = touches.length, i, gesture;110 111    if (touchending) clearTimeout(touchending);112    touchending = setTimeout(function() { touchending = null; }, 500); // Ghost clicks are delayed!113    for (i = 0; i < n; ++i) {114      if (gesture = gestures[touches[i].identifier]) {115        nopropagation(event);116        gesture("end", event, touches[i]);117      }118    }119  }120 121  function beforestart(that, container, event, d, identifier, touch) {122    var dispatch = listeners.copy(),123        p = pointer(touch || event, container), dx, dy,124        s;125 126    if ((s = subject.call(that, new DragEvent("beforestart", {127        sourceEvent: event,128        target: drag,129        identifier,130        active,131        x: p[0],132        y: p[1],133        dx: 0,134        dy: 0,135        dispatch136      }), d)) == null) return;137 138    dx = s.x - p[0] || 0;139    dy = s.y - p[1] || 0;140 141    return function gesture(type, event, touch) {142      var p0 = p, n;143      switch (type) {144        case "start": gestures[identifier] = gesture, n = active++; break;145        case "end": delete gestures[identifier], --active; // falls through146        case "drag": p = pointer(touch || event, container), n = active; break;147      }148      dispatch.call(149        type,150        that,151        new DragEvent(type, {152          sourceEvent: event,153          subject: s,154          target: drag,155          identifier,156          active: n,157          x: p[0] + dx,158          y: p[1] + dy,159          dx: p[0] - p0[0],160          dy: p[1] - p0[1],161          dispatch162        }),163        d164      );165    };166  }167 168  drag.filter = function(_) {169    return arguments.length ? (filter = typeof _ === "function" ? _ : constant(!!_), drag) : filter;170  };171 172  drag.container = function(_) {173    return arguments.length ? (container = typeof _ === "function" ? _ : constant(_), drag) : container;174  };175 176  drag.subject = function(_) {177    return arguments.length ? (subject = typeof _ === "function" ? _ : constant(_), drag) : subject;178  };179 180  drag.touchable = function(_) {181    return arguments.length ? (touchable = typeof _ === "function" ? _ : constant(!!_), drag) : touchable;182  };183 184  drag.on = function() {185    var value = listeners.on.apply(listeners, arguments);186    return value === listeners ? drag : value;187  };188 189  drag.clickDistance = function(_) {190    return arguments.length ? (clickDistance2 = (_ = +_) * _, drag) : Math.sqrt(clickDistance2);191  };192 193  return drag;194}195