Adding get swipe options

lib/driver.js

@@ -7,6 +7,7 @@ import log from './logger';
 import { desiredCapabilityConstraints, validator } from './desired-caps';
 import B from 'bluebird';
 import _ from 'lodash';
+import { util } from 'appium-support';
 
 validator.promise = B;
 validator.prettify = (val) => { return val; };
@@ -187,6 +188,33 @@ class BaseDriver extends MobileJsonWireProtocol {
   }
  }
 
+ async getSwipeOptions (gestures, touchCount = 1) {
+   let startX =  this.helpers.getCoordDefault(gestures[0].options.x),
+       startY = this.helpers.getCoordDefault(gestures[0].options.y),
+       endX = this.helpers.getCoordDefault(gestures[2].options.x),
+       endY = this.helpers.getCoordDefault(gestures[2].options.y),
+       duration = this.helpers.getSwipeTouchDuration(gestures[1]),
+       element = gestures[0].options.element,
+       destElement = gestures[2].options.element || gestures[0].options.element;
+
+   // there's no destination element handling in bootstrap and since it applies to all platforms, we handle it here
+   if (util.hasValue(destElement)) {
+     let locResult = await this.getLocationInView(destElement);
+     let sizeResult = await this.getSize(destElement);
+     let offsetX = (Math.abs(endX) < 1 && Math.abs(endX) > 0) ? sizeResult.width * endX : endX;
+     let offsetY = (Math.abs(endY) < 1 && Math.abs(endY) > 0) ? sizeResult.height * endY : endY;
+     endX = locResult.x + offsetX;
+     endY = locResult.y + offsetY;
+     // if the target element was provided, the coordinates for the destination need to be relative to it.
+     if (util.hasValue(element)) {
+       let firstElLocation = await this.getLocationInView(element);
+       endX -= firstElLocation.x;
+       endY -= firstElLocation.y;
+     }
+   }
+   // clients are responsible to use these options correctly
+   return {startX, startY, endX, endY, duration, touchCount, element};
+ }
 }
 
 for (let [cmd, fn] of _.pairs(commands)) {

lib/helpers.js

@@ -4,7 +4,7 @@ import url from 'url';
 import logger from './logger';
 import _fs from 'fs';
 import B from 'bluebird';
-import { tempDir, system, fs } from 'appium-support';
+import { tempDir, system, fs, util } from 'appium-support';
 import { exec } from 'teen_process';
 import AdmZip from 'adm-zip';
 import request from 'request-promise';
@@ -188,5 +188,28 @@ function isPackageOrBundle (app) {
   return (/^([a-zA-Z0-9\-_]+\.[a-zA-Z0-9\-_]+)+$/).test(app);
 }
 
-export default { configureApp, downloadApp, downloadFile, copyLocalZip,
-                 unzipApp, unzipFile, testZipArchive, isPackageOrBundle };
+function getCoordDefault (val) {
+  // going the long way and checking for undefined and null since
+  // we can't be assured `elId` is a string and not an int. Same
+  // thing with destElement below.
+  return util.hasValue(val) ? val : 0.5;
+}
+
+function getSwipeTouchDuration (waitGesture) {
+  // the touch action api uses ms, we want seconds
+  // 0.8 is the default time for the operation
+  let duration = 0.8;
+  if (typeof waitGesture.options.ms !== 'undefined' && waitGesture.options.ms) {
+    duration = waitGesture.options.ms / 1000;
+    if (duration === 0) {
+      // set to a very low number, since they wanted it fast
+      // but below 0.1 becomes 0 steps, which causes errors
+      duration = 0.1;
+    }
+  }
+  return duration;
+}
+
+export default {configureApp, downloadApp, downloadFile, copyLocalZip,
+                unzipApp, unzipFile, testZipArchive, isPackageOrBundle,
+                getCoordDefault, getSwipeTouchDuration};