Files
blockly/core/workspace_dragger.ts
Beka Westberg 42b8c6e3ab fix: return annotations (#7118)
* chore: remove suppress annotations

* chore: remove fileoverview annotation

* chore: remove other unused annotations

* chore: change return to returns

* chore: enable tag linting
2023-05-24 13:01:33 -07:00

99 lines
2.7 KiB
TypeScript

/**
* @license
* Copyright 2017 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* Methods for dragging a workspace visually.
*
* @class
*/
import * as goog from '../closure/goog/goog.js';
goog.declareModuleId('Blockly.WorkspaceDragger');
import * as common from './common.js';
import {Coordinate} from './utils/coordinate.js';
import type {WorkspaceSvg} from './workspace_svg.js';
/**
* Class for a workspace dragger. It moves the workspace around when it is
* being dragged by a mouse or touch.
*
*/
export class WorkspaceDragger {
private readonly horizontalScrollEnabled_: boolean;
private readonly verticalScrollEnabled_: boolean;
protected startScrollXY_: Coordinate;
/** @param workspace The workspace to drag. */
constructor(private workspace: WorkspaceSvg) {
/** Whether horizontal scroll is enabled. */
this.horizontalScrollEnabled_ = this.workspace.isMovableHorizontally();
/** Whether vertical scroll is enabled. */
this.verticalScrollEnabled_ = this.workspace.isMovableVertically();
/**
* The scroll position of the workspace at the beginning of the drag.
* Coordinate system: pixel coordinates.
*/
this.startScrollXY_ = new Coordinate(workspace.scrollX, workspace.scrollY);
}
/**
* Sever all links from this object.
*
* @internal
*/
dispose() {
// AnyDuringMigration because: Type 'null' is not assignable to type
// 'WorkspaceSvg'.
this.workspace = null as AnyDuringMigration;
}
/**
* Start dragging the workspace.
*
* @internal
*/
startDrag() {
if (common.getSelected()) {
common.getSelected()!.unselect();
}
}
/**
* Finish dragging the workspace and put everything back where it belongs.
*
* @param currentDragDeltaXY How far the pointer has moved from the position
* at the start of the drag, in pixel coordinates.
* @internal
*/
endDrag(currentDragDeltaXY: Coordinate) {
// Make sure everything is up to date.
this.drag(currentDragDeltaXY);
}
/**
* Move the workspace based on the most recent mouse movements.
*
* @param currentDragDeltaXY How far the pointer has moved from the position
* at the start of the drag, in pixel coordinates.
* @internal
*/
drag(currentDragDeltaXY: Coordinate) {
const newXY = Coordinate.sum(this.startScrollXY_, currentDragDeltaXY);
if (this.horizontalScrollEnabled_ && this.verticalScrollEnabled_) {
this.workspace.scroll(newXY.x, newXY.y);
} else if (this.horizontalScrollEnabled_) {
this.workspace.scroll(newXY.x, this.workspace.scrollY);
} else if (this.verticalScrollEnabled_) {
this.workspace.scroll(this.workspace.scrollX, newXY.y);
} else {
throw new TypeError('Invalid state.');
}
}
}