mixio 1.10.0

blockly/core/browser_events.js

@@ -0,0 +1,175 @@
+/**
+ * @license
+ * Copyright 2021 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @fileoverview Browser event handling.
+ * @author fenichel@google.com (Rachel Fenichel)
+ */
+'use strict';
+
+goog.provide('Blockly.browserEvents');
+
+goog.require('Blockly.Touch');
+goog.require('Blockly.utils.global');
+
+
+/**
+ * Blockly opaque event data used to unbind events when using
+ * `Blockly.browserEvents.bind` and
+ * `Blockly.browserEvents.conditionalBind`.
+ * @typedef {!Array<!Array>}
+ */
+Blockly.browserEvents.Data;
+
+/**
+ * Bind an event handler that can be ignored if it is not part of the active
+ * touch stream.
+ * Use this for events that either start or continue a multi-part gesture (e.g.
+ * mousedown or mousemove, which may be part of a drag or click).
+ * @param {!EventTarget} node Node upon which to listen.
+ * @param {string} name Event name to listen to (e.g. 'mousedown').
+ * @param {?Object} thisObject The value of 'this' in the function.
+ * @param {!Function} func Function to call when event is triggered.
+ * @param {boolean=} opt_noCaptureIdentifier True if triggering on this event
+ *     should not block execution of other event handlers on this touch or
+ *     other simultaneous touches.  False by default.
+ * @param {boolean=} opt_noPreventDefault True if triggering on this event
+ *     should prevent the default handler.  False by default.  If
+ *     opt_noPreventDefault is provided, opt_noCaptureIdentifier must also be
+ *     provided.
+ * @return {!Blockly.browserEvents.Data} Opaque data that can be passed to
+ *     unbindEvent_.
+ * @public
+ */
+Blockly.browserEvents.conditionalBind = function(
+    node, name, thisObject, func, opt_noCaptureIdentifier,
+    opt_noPreventDefault) {
+  var handled = false;
+  var wrapFunc = function(e) {
+    var captureIdentifier = !opt_noCaptureIdentifier;
+    // Handle each touch point separately.  If the event was a mouse event, this
+    // will hand back an array with one element, which we're fine handling.
+    var events = Blockly.Touch.splitEventByTouches(e);
+    for (var i = 0, event; (event = events[i]); i++) {
+      if (captureIdentifier && !Blockly.Touch.shouldHandleEvent(event)) {
+        continue;
+      }
+      Blockly.Touch.setClientFromTouch(event);
+      if (thisObject) {
+        func.call(thisObject, event);
+      } else {
+        func(event);
+      }
+      handled = true;
+    }
+  };
+
+  var bindData = [];
+  if (Blockly.utils.global['PointerEvent'] &&
+      (name in Blockly.Touch.TOUCH_MAP)) {
+    for (var i = 0, type; (type = Blockly.Touch.TOUCH_MAP[name][i]); i++) {
+      node.addEventListener(type, wrapFunc, false);
+      bindData.push([node, type, wrapFunc]);
+    }
+  } else {
+    node.addEventListener(name, wrapFunc, false);
+    bindData.push([node, name, wrapFunc]);
+
+    // Add equivalent touch event.
+    if (name in Blockly.Touch.TOUCH_MAP) {
+      var touchWrapFunc = function(e) {
+        wrapFunc(e);
+        // Calling preventDefault stops the browser from scrolling/zooming the
+        // page.
+        var preventDef = !opt_noPreventDefault;
+        if (handled && preventDef) {
+          e.preventDefault();
+        }
+      };
+      for (var i = 0, type; (type = Blockly.Touch.TOUCH_MAP[name][i]); i++) {
+        node.addEventListener(type, touchWrapFunc, false);
+        bindData.push([node, type, touchWrapFunc]);
+      }
+    }
+  }
+  return bindData;
+};
+
+
+/**
+ * Bind an event handler that should be called regardless of whether it is part
+ * of the active touch stream.
+ * Use this for events that are not part of a multi-part gesture (e.g.
+ * mouseover for tooltips).
+ * @param {!EventTarget} node Node upon which to listen.
+ * @param {string} name Event name to listen to (e.g. 'mousedown').
+ * @param {?Object} thisObject The value of 'this' in the function.
+ * @param {!Function} func Function to call when event is triggered.
+ * @return {!Blockly.browserEvents.Data} Opaque data that can be passed to
+ *     unbindEvent_.
+ * @public
+ */
+Blockly.browserEvents.bind = function(node, name, thisObject, func) {
+  var wrapFunc = function(e) {
+    if (thisObject) {
+      func.call(thisObject, e);
+    } else {
+      func(e);
+    }
+  };
+
+  var bindData = [];
+  if (Blockly.utils.global['PointerEvent'] &&
+      (name in Blockly.Touch.TOUCH_MAP)) {
+    for (var i = 0, type; (type = Blockly.Touch.TOUCH_MAP[name][i]); i++) {
+      node.addEventListener(type, wrapFunc, false);
+      bindData.push([node, type, wrapFunc]);
+    }
+  } else {
+    node.addEventListener(name, wrapFunc, false);
+    bindData.push([node, name, wrapFunc]);
+
+    // Add equivalent touch event.
+    if (name in Blockly.Touch.TOUCH_MAP) {
+      var touchWrapFunc = function(e) {
+        // Punt on multitouch events.
+        if (e.changedTouches && e.changedTouches.length == 1) {
+          // Map the touch event's properties to the event.
+          var touchPoint = e.changedTouches[0];
+          e.clientX = touchPoint.clientX;
+          e.clientY = touchPoint.clientY;
+        }
+        wrapFunc(e);
+
+        // Stop the browser from scrolling/zooming the page.
+        e.preventDefault();
+      };
+      for (var i = 0, type; (type = Blockly.Touch.TOUCH_MAP[name][i]); i++) {
+        node.addEventListener(type, touchWrapFunc, false);
+        bindData.push([node, type, touchWrapFunc]);
+      }
+    }
+  }
+  return bindData;
+};
+
+/**
+ * Unbind one or more events event from a function call.
+ * @param {!Blockly.browserEvents.Data} bindData Opaque data from bindEvent_.
+ *     This list is emptied during the course of calling this function.
+ * @return {!Function} The function call.
+ * @public
+ */
+Blockly.browserEvents.unbind = function(bindData) {
+  while (bindData.length) {
+    var bindDatum = bindData.pop();
+    var node = bindDatum[0];
+    var name = bindDatum[1];
+    var func = bindDatum[2];
+    node.removeEventListener(name, func, false);
+  }
+  return func;
+};