Modularise handlers.

2015-02-11 15:53:42 +00:00
parent 0acf3602f0
commit a52a945226
9 changed files with 729 additions and 600 deletions
@@ -0,0 +1,170 @@
+/* Copyright (c) 2015 Hyunje Alex Jun and other contributors
+ * Licensed under the MIT License
+ */
+'use strict';
+
+var instances = require('../instances')
+  , updateGeometry = require('../update');
+
+function bindTouchHandler(element, i, supportsTouch, supportsIePointer) {
+  function shouldPreventDefault(deltaX, deltaY) {
+    var scrollTop = element.scrollTop;
+    var scrollLeft = element.scrollLeft;
+    var magnitudeX = Math.abs(deltaX);
+    var magnitudeY = Math.abs(deltaY);
+
+    if (magnitudeY > magnitudeX) {
+      // user is perhaps trying to swipe up/down the page
+
+      if (((deltaY < 0) && (scrollTop === i.contentHeight - i.containerHeight)) ||
+          ((deltaY > 0) && (scrollTop === 0))) {
+        return !i.settings.swipePropagation;
+      }
+    } else if (magnitudeX > magnitudeY) {
+      // user is perhaps trying to swipe left/right across the page
+
+      if (((deltaX < 0) && (scrollLeft === i.contentWidth - i.containerWidth)) ||
+          ((deltaX > 0) && (scrollLeft === 0))) {
+        return !i.settings.swipePropagation;
+      }
+    }
+
+    return true;
+  }
+
+  function applyTouchMove(differenceX, differenceY) {
+    element.scrollTop = element.scrollTop - differenceY;
+    element.scrollLeft = element.scrollLeft() - differenceX;
+
+    updateGeometry(element);
+  }
+
+  var startOffset = {};
+  var startTime = 0;
+  var speed = {};
+  var easingLoop = null;
+  var inGlobalTouch = false;
+  var inLocalTouch = false;
+
+  function globalTouchStart() {
+    inGlobalTouch = true;
+  }
+  function globalTouchEnd() {
+    inGlobalTouch = false;
+  }
+
+  function getTouch(e) {
+    if (e.targetTouches) {
+      return e.targetTouches[0];
+    } else {
+      // Maybe IE pointer
+      return e;
+    }
+  }
+  function shouldHandle(e) {
+    if (e.targetTouches && e.targetTouches.length === 1) {
+      return true;
+    }
+    if (e.pointerType && e.pointerType !== 'mouse' && e.pointerType !== e.MSPOINTER_TYPE_MOUSE) {
+      return true;
+    }
+    return false;
+  }
+  function touchStart(e) {
+    if (shouldHandle(e)) {
+      inLocalTouch = true;
+
+      var touch = getTouch(e);
+
+      startOffset.pageX = touch.pageX;
+      startOffset.pageY = touch.pageY;
+
+      startTime = (new Date()).getTime();
+
+      if (easingLoop !== null) {
+        clearInterval(easingLoop);
+      }
+
+      e.stopPropagation();
+    }
+  }
+  function touchMove(e) {
+    if (!inGlobalTouch && inLocalTouch && shouldHandle(e)) {
+      var touch = getTouch(e);
+
+      var currentOffset = {pageX: touch.pageX, pageY: touch.pageY};
+
+      var differenceX = currentOffset.pageX - startOffset.pageX;
+      var differenceY = currentOffset.pageY - startOffset.pageY;
+
+      applyTouchMove(differenceX, differenceY);
+      startOffset = currentOffset;
+
+      var currentTime = (new Date()).getTime();
+
+      var timeGap = currentTime - startTime;
+      if (timeGap > 0) {
+        speed.x = differenceX / timeGap;
+        speed.y = differenceY / timeGap;
+        startTime = currentTime;
+      }
+
+      if (shouldPreventDefault(differenceX, differenceY)) {
+        e.stopPropagation();
+        e.preventDefault();
+      }
+    }
+  }
+  function touchEnd() {
+    if (!inGlobalTouch && inLocalTouch) {
+      inLocalTouch = false;
+
+      clearInterval(easingLoop);
+      easingLoop = setInterval(function () {
+        if (!instances.get(element)) {
+          clearInterval(easingLoop);
+          return;
+        }
+
+        if (Math.abs(speed.x) < 0.01 && Math.abs(speed.y) < 0.01) {
+          clearInterval(easingLoop);
+          return;
+        }
+
+        applyTouchMove(speed.x * 30, speed.y * 30);
+
+        speed.x *= 0.8;
+        speed.y *= 0.8;
+      }, 10);
+    }
+  }
+
+  if (supportsTouch) {
+    i.event.bind(window, 'touchstart', globalTouchStart);
+    i.event.bind(window, 'touchend', globalTouchEnd);
+    i.event.bind(element, 'touchstart', touchStart);
+    i.event.bind(element, 'touchmove', touchMove);
+    i.event.bind(element, 'touchend', touchEnd);
+  }
+
+  if (supportsIePointer) {
+    if (window.PointerEvent) {
+      i.event.bind(window, 'pointerdown', globalTouchStart);
+      i.event.bind(window, 'pointerup', globalTouchEnd);
+      i.event.bind(element, 'pointerdown', touchStart);
+      i.event.bind(element, 'pointermove', touchMove);
+      i.event.bind(element, 'pointerup', touchEnd);
+    } else if (window.MSPointerEvent) {
+      i.event.bind(window, 'MSPointerDown', globalTouchStart);
+      i.event.bind(window, 'MSPointerUp', globalTouchEnd);
+      i.event.bind(element, 'MSPointerDown', touchStart);
+      i.event.bind(element, 'MSPointerMove', touchMove);
+      i.event.bind(element, 'MSPointerUp', touchEnd);
+    }
+  }
+}
+
+module.exports = function (element, supportsTouch, supportsIePointer) {
+  var i = instances.get(element);
+  bindTouchHandler(element, i, supportsTouch, supportsIePointer);
+};