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115 lines
3.2 KiB
JavaScript
115 lines
3.2 KiB
JavaScript
/**
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* @license
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* Copyright 2017 Google LLC
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* SPDX-License-Identifier: Apache-2.0
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*/
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/**
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* @fileoverview Methods for dragging a workspace visually.
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* @author fenichel@google.com (Rachel Fenichel)
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*/
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'use strict';
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goog.module('Blockly.WorkspaceDragger');
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goog.module.declareLegacyNamespace();
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// TODO(#5073): Add Blockly require after fixing circular dependency.
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// goog.require('Blockly');
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const Coordinate = goog.require('Blockly.utils.Coordinate');
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/* eslint-disable-next-line no-unused-vars */
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const WorkspaceSvg = goog.requireType('Blockly.WorkspaceSvg');
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/**
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* Class for a workspace dragger. It moves the workspace around when it is
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* being dragged by a mouse or touch.
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* Note that the workspace itself manages whether or not it has a drag surface
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* and how to do translations based on that. This simply passes the right
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* commands based on events.
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* @param {!WorkspaceSvg} workspace The workspace to drag.
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* @constructor
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*/
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const WorkspaceDragger = function(workspace) {
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/**
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* @type {!WorkspaceSvg}
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* @private
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*/
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this.workspace_ = workspace;
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/**
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* Whether horizontal scroll is enabled.
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* @type {boolean}
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* @private
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*/
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this.horizontalScrollEnabled_ = this.workspace_.isMovableHorizontally();
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/**
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* Whether vertical scroll is enabled.
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* @type {boolean}
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* @private
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*/
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this.verticalScrollEnabled_ = this.workspace_.isMovableVertically();
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/**
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* The scroll position of the workspace at the beginning of the drag.
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* Coordinate system: pixel coordinates.
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* @type {!Coordinate}
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* @protected
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*/
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this.startScrollXY_ = new Coordinate(workspace.scrollX, workspace.scrollY);
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};
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/**
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* Sever all links from this object.
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* @package
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* @suppress {checkTypes}
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*/
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WorkspaceDragger.prototype.dispose = function() {
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this.workspace_ = null;
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};
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/**
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* Start dragging the workspace.
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* @package
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*/
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WorkspaceDragger.prototype.startDrag = function() {
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if (Blockly.selected) {
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Blockly.selected.unselect();
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}
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this.workspace_.setupDragSurface();
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};
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/**
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* Finish dragging the workspace and put everything back where it belongs.
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* @param {!Coordinate} currentDragDeltaXY How far the pointer has
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* moved from the position at the start of the drag, in pixel coordinates.
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* @package
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*/
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WorkspaceDragger.prototype.endDrag = function(currentDragDeltaXY) {
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// Make sure everything is up to date.
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this.drag(currentDragDeltaXY);
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this.workspace_.resetDragSurface();
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};
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/**
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* Move the workspace based on the most recent mouse movements.
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* @param {!Coordinate} currentDragDeltaXY How far the pointer has
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* moved from the position at the start of the drag, in pixel coordinates.
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* @package
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*/
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WorkspaceDragger.prototype.drag = function(currentDragDeltaXY) {
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const newXY = Coordinate.sum(this.startScrollXY_, currentDragDeltaXY);
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if (this.horizontalScrollEnabled_ && this.verticalScrollEnabled_) {
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this.workspace_.scroll(newXY.x, newXY.y);
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} else if (this.horizontalScrollEnabled_) {
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this.workspace_.scroll(newXY.x, this.workspace_.scrollY);
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} else if (this.verticalScrollEnabled_) {
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this.workspace_.scroll(this.workspace_.scrollX, newXY.y);
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} else {
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throw new TypeError('Invalid state.');
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}
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};
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exports = WorkspaceDragger;
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