Initial commit of 001code-html Scratch frontend project.

Includes scratch-gui, scratch-vm, scratch-blocks, scratch-render, scratch-l10n, and deployment config.

Co-authored-by: Cursor <cursoragent@cursor.com>

scratch-blocks/core/touch.js

@@ -0,0 +1,226 @@
+/**
+ * @license
+ * Visual Blocks Editor
+ *
+ * Copyright 2016 Google Inc.
+ * https://developers.google.com/blockly/
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * @fileoverview Touch handling for Blockly.
+ * @author fenichel@google.com (Rachel Fenichel)
+ */
+'use strict';
+
+/**
+ * @name Blockly.Touch
+ * @namespace
+ **/
+goog.provide('Blockly.Touch');
+
+goog.require('goog.events');
+goog.require('goog.events.BrowserFeature');
+goog.require('goog.string');
+
+
+/**
+ * Which touch events are we currently paying attention to?
+ * @type {DOMString}
+ * @private
+ */
+Blockly.Touch.touchIdentifier_ = null;
+
+/**
+ * The TOUCH_MAP lookup dictionary specifies additional touch events to fire,
+ * in conjunction with mouse events.
+ * @type {Object}
+ */
+Blockly.Touch.TOUCH_MAP = {};
+if (goog.events.BrowserFeature.TOUCH_ENABLED) {
+  Blockly.Touch.TOUCH_MAP = {
+    'mousedown': ['touchstart'],
+    'mousemove': ['touchmove'],
+    'mouseup': ['touchend', 'touchcancel']
+  };
+}
+
+/**
+ * PID of queued long-press task.
+ * @private
+ */
+Blockly.longPid_ = 0;
+
+/**
+ * Context menus on touch devices are activated using a long-press.
+ * Unfortunately the contextmenu touch event is currently (2015) only supported
+ * by Chrome.  This function is fired on any touchstart event, queues a task,
+ * which after about a second opens the context menu.  The tasks is killed
+ * if the touch event terminates early.
+ * @param {!Event} e Touch start event.
+ * @param {Blockly.Gesture} gesture The gesture that triggered this longStart.
+ * @private
+ */
+Blockly.longStart_ = function(e, gesture) {
+  Blockly.longStop_();
+  // Punt on multitouch events.
+  if (e.changedTouches.length != 1) {
+    return;
+  }
+  Blockly.longPid_ = setTimeout(function() {
+    e.button = 2;  // Simulate a right button click.
+    // e was a touch event.  It needs to pretend to be a mouse event.
+    e.clientX = e.changedTouches[0].clientX;
+    e.clientY = e.changedTouches[0].clientY;
+
+    // Let the gesture route the right-click correctly.
+    if (gesture) {
+      gesture.handleRightClick(e);
+    }
+  }, Blockly.LONGPRESS);
+};
+
+/**
+ * Nope, that's not a long-press.  Either touchend or touchcancel was fired,
+ * or a drag hath begun.  Kill the queued long-press task.
+ * @private
+ */
+Blockly.longStop_ = function() {
+  if (Blockly.longPid_) {
+    clearTimeout(Blockly.longPid_);
+    Blockly.longPid_ = 0;
+  }
+};
+
+/**
+ * Clear the touch identifier that tracks which touch stream to pay attention
+ * to.  This ends the current drag/gesture and allows other pointers to be
+ * captured.
+ */
+Blockly.Touch.clearTouchIdentifier = function() {
+  Blockly.Touch.touchIdentifier_ = null;
+};
+
+/**
+ * Decide whether Blockly should handle or ignore this event.
+ * Mouse and touch events require special checks because we only want to deal
+ * with one touch stream at a time.  All other events should always be handled.
+ * @param {!Event} e The event to check.
+ * @return {boolean} True if this event should be passed through to the
+ *     registered handler; false if it should be blocked.
+ */
+Blockly.Touch.shouldHandleEvent = function(e) {
+  return !Blockly.Touch.isMouseOrTouchEvent(e) ||
+      Blockly.Touch.checkTouchIdentifier(e);
+};
+
+/**
+ * Get the touch identifier from the given event.  If it was a mouse event, the
+ * identifier is the string 'mouse'.
+ * @param {!Event} e Mouse event or touch event.
+ * @return {string} The touch identifier from the first changed touch, if
+ *     defined.  Otherwise 'mouse'.
+ */
+Blockly.Touch.getTouchIdentifierFromEvent = function(e) {
+  return (e.changedTouches && e.changedTouches[0] &&
+      e.changedTouches[0].identifier != undefined &&
+      e.changedTouches[0].identifier != null) ?
+      e.changedTouches[0].identifier : 'mouse';
+};
+
+/**
+ * Check whether the touch identifier on the event matches the current saved
+ * identifier.  If there is no identifier, that means it's a mouse event and
+ * we'll use the identifier "mouse".  This means we won't deal well with
+ * multiple mice being used at the same time.  That seems okay.
+ * If the current identifier was unset, save the identifier from the
+ * event.  This starts a drag/gesture, during which touch events with other
+ * identifiers will be silently ignored.
+ * @param {!Event} e Mouse event or touch event.
+ * @return {boolean} Whether the identifier on the event matches the current
+ *     saved identifier.
+ */
+Blockly.Touch.checkTouchIdentifier = function(e) {
+  var identifier = Blockly.Touch.getTouchIdentifierFromEvent(e);
+
+  // if (Blockly.touchIdentifier_ )is insufficient because Android touch
+  // identifiers may be zero.
+  if (Blockly.Touch.touchIdentifier_ != undefined &&
+      Blockly.Touch.touchIdentifier_ != null) {
+    // We're already tracking some touch/mouse event.  Is this from the same
+    // source?
+    return Blockly.Touch.touchIdentifier_ == identifier;
+  }
+  if (e.type == 'mousedown' || e.type == 'touchstart') {
+    // No identifier set yet, and this is the start of a drag.  Set it and
+    // return.
+    Blockly.Touch.touchIdentifier_ = identifier;
+    return true;
+  }
+  // There was no identifier yet, but this wasn't a start event so we're going
+  // to ignore it.  This probably means that another drag finished while this
+  // pointer was down.
+  return false;
+};
+
+/**
+ * Set an event's clientX and clientY from its first changed touch.  Use this to
+ * make a touch event work in a mouse event handler.
+ * @param {!Event} e A touch event.
+ */
+Blockly.Touch.setClientFromTouch = function(e) {
+  if (Blockly.utils.startsWith(e.type, 'touch')) {
+    // Map the touch event's properties to the event.
+    var touchPoint = e.changedTouches[0];
+    e.clientX = touchPoint.clientX;
+    e.clientY = touchPoint.clientY;
+  }
+};
+
+/**
+ * Check whether a given event is a mouse or touch event.
+ * @param {!Event} e An event.
+ * @return {boolean} true if it is a mouse or touch event; false otherwise.
+ */
+Blockly.Touch.isMouseOrTouchEvent = function(e) {
+  return Blockly.utils.startsWith(e.type, 'touch') ||
+      Blockly.utils.startsWith(e.type, 'mouse');
+};
+
+/**
+ * Split an event into an array of events, one per changed touch or mouse
+ * point.
+ * @param {!Event} e A mouse event or a touch event with one or more changed
+ * touches.
+ * @return {!Array.<!Event>} An array of mouse or touch events.  Each touch
+ *     event will have exactly one changed touch.
+ */
+Blockly.Touch.splitEventByTouches = function(e) {
+  var events = [];
+  if (e.changedTouches) {
+    for (var i = 0; i < e.changedTouches.length; i++) {
+      var newEvent = {
+        type: e.type,
+        changedTouches: [e.changedTouches[i]],
+        target: e.target,
+        stopPropagation: function(){ e.stopPropagation(); },
+        preventDefault: function(){ e.preventDefault(); }
+      };
+      events[i] = newEvent;
+    }
+  } else {
+    events.push(e);
+  }
+  return events;
+};