Files
blockly/core/workspace_dragger.ts
Aaron Dodson 61bbd7dbf6 chore: Remove underscores from private fields. (#8682)
* chore: Remove underscores from private fields.

* refactor: Use public APIs in tests where possible.
2024-12-02 11:33:05 -08:00

98 lines
2.7 KiB
TypeScript

/**
* @license
* Copyright 2017 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* Methods for dragging a workspace visually.
*
* @class
*/
// Former goog.module ID: 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.');
}
}
}