Inline _ignoreEvent into mousedown

mousemove or mouseup handlers are bound only during the drag, and should never be ignored.

src/ui/handler/drag_rotate.js

@@ -91,9 +91,21 @@ class DragRotateHandler {
  }
 
  _onDown(e: MouseEvent) {
- if (this._ignoreEvent(e)) return;
+ if (this._map.boxZoom && this._map.boxZoom.isActive()) return;
+ if (this._map.dragPan && this._map.dragPan.isActive()) return;
  if (this.isActive()) return;
 
+ const button = (e.ctrlKey ? 0 : 2); // ? ctrl+left button : right button
+ let eventButton = e.button;
+ if (typeof window.InstallTrigger !== 'undefined' && e.button === 2 && e.ctrlKey &&
+ window.navigator.platform.toUpperCase().indexOf('MAC') >= 0) {
+ // Fix for https://github.com/mapbox/mapbox-gl-js/issues/3131:
+ // Firefox (detected by InstallTrigger) on Mac determines e.button = 2 when
+ // using Control + left click
+ eventButton = 0;
+ }
+ if (eventButton !== button) return;
+
  window.document.addEventListener('mousemove', this._onMove, {capture: true});
  window.document.addEventListener('mouseup', this._onUp);
  /* Deactivate DragRotate when the window looses focus. Otherwise if a mouseup occurs when the window isn't in focus, DragRotate will still be active even though the mouse is no longer pressed. */
@@ -108,8 +120,6 @@ class DragRotateHandler {
  }
 
  _onMove(e: MouseEvent) {
- if (this._ignoreEvent(e)) return;
-
  if (!this.isActive()) {
  this._active = true;
  this._map.moving = true;
@@ -148,7 +158,6 @@ class DragRotateHandler {
  }
 
  _onUp(e: MouseEvent) {
- if (this._ignoreEvent(e)) return;
  window.document.removeEventListener('mousemove', this._onMove, {capture: true});
  window.document.removeEventListener('mouseup', this._onUp);
  window.removeEventListener('blur', (this._onUp: any));
@@ -216,24 +225,6 @@ class DragRotateHandler {
  return this._map.fire(type, { originalEvent: e });
  }
 
- _ignoreEvent(e: MouseEvent) {
- const map = this._map;
-
- if (map.boxZoom && map.boxZoom.isActive()) return true;
- if (map.dragPan && map.dragPan.isActive()) return true;
-
- const button = (e.ctrlKey ? 0 : 2); // ? ctrl+left button : right button
- let eventButton = e.button;
- if (typeof window.InstallTrigger !== 'undefined' && e.button === 2 && e.ctrlKey &&
- window.navigator.platform.toUpperCase().indexOf('MAC') >= 0) {
- // Fix for https://github.com/mapbox/mapbox-gl-js/issues/3131:
- // Firefox (detected by InstallTrigger) on Mac determines e.button = 2 when
- // using Control + left click
- eventButton = 0;
- }
- return e.type !== 'mousemove' && !this.isActive() && eventButton !== button;
- }
-
  _drainInertiaBuffer() {
  const inertia = this._inertia,
  now = Date.now(),