From 3c7033f92edd034d1ec1ed4cbbddab62974d95a8 Mon Sep 17 00:00:00 2001
From: jdotzki <joerg.dotzki@zalando.de>
Date: Mon, 23 Jun 2014 17:16:13 +0200
Subject: [PATCH] feat(features/touch): add touch gesture support

Allow to navigate i.e. scroll/zoom on the diagram via touch gestures.

Closes #46
---
 lib/Viewer.js                                 |   7 +-
 lib/features/movecanvas/MoveCanvas.js         |  24 +--
 lib/features/touch/TouchInteraction.js        | 172 ++++++++++++++++++
 lib/features/touch/index.js                   |   4 +
 lib/features/zoomscroll/ZoomScroll.js         |   1 +
 test/spec/browser/ViewerSpec.js               |   1 +
 .../features/touch/TouchInteractionSpec.js    |  37 ++++
 .../features/zoomscoll/ZoomScrollSpec.js      |   2 +-
 8 files changed, 233 insertions(+), 15 deletions(-)
 create mode 100644 lib/features/touch/TouchInteraction.js
 create mode 100644 lib/features/touch/index.js
 create mode 100644 test/spec/browser/features/touch/TouchInteractionSpec.js

diff --git a/lib/Viewer.js b/lib/Viewer.js
index 1a5e222b..2c150ecf 100644
--- a/lib/Viewer.js
+++ b/lib/Viewer.js
@@ -10,11 +10,12 @@ var Importer = require('./import/Importer'),
 
 
 function getSvgContents(diagram) {
-  var paper = diagram.get('canvas').getPaper();
-  var outerNode = paper.node.parentNode;
+  var outerNode = diagram.get('canvas').getContainer();
 
   var svg = outerNode.innerHTML;
-  return svg.replace(/^<svg[^>]*>|<\/svg>$/g, '');
+  return svg.replace(/^<svg[^>]*>|<\/svg>$/g, '')
+            .replace('<desc>Created with Snap</desc>', '')
+            .replace(/<g class="viewport"( transform="[^"]*")?/, '<g');
 }
 
 function initListeners(diagram, listeners) {
diff --git a/lib/features/movecanvas/MoveCanvas.js b/lib/features/movecanvas/MoveCanvas.js
index 05a64b7f..e589e6a7 100644
--- a/lib/features/movecanvas/MoveCanvas.js
+++ b/lib/features/movecanvas/MoveCanvas.js
@@ -1,7 +1,7 @@
 'use strict';
 
 var $ = require('jquery');
-
+var _ = require('lodash');
 
 function MoveCanvas(events, canvas) {
 
@@ -9,7 +9,7 @@ function MoveCanvas(events, canvas) {
 
   function init(element) {
 
-    var context;
+    var context = {};
 
     function getPosition(e) {
       return { x: e.clientX, y: e.clientY };
@@ -40,30 +40,33 @@ function MoveCanvas(events, canvas) {
 
       var position = getPosition(event);
 
-      var delta = getDelta(context.start, position);
 
-      if (!context.dragging && isThresholdReached(delta)) {
+      if (!context.dragging && isThresholdReached(getDelta(context.start, position))) {
         context.dragging = true;
 
         context.cursor = cursor('move');
       }
 
+
       if (context.dragging) {
 
-        var box = context.viewbox;
+        var lastPos = context.last || context.start;
 
-        canvas.viewbox({
-          x: box.x + delta.x / box.scale,
-          y: box.y + delta.y / box.scale,
-          width: box.width,
-          height: box.height
+        var delta = getDelta(position, lastPos);
+
+        canvas.scroll({
+          dx: delta.x,
+          dy: delta.y
         });
+
+        context.last = position;
       }
 
       // prevent select
       event.preventDefault();
     }
 
+
     function handleEnd(event) {
       $(element).off('mousemove', handleMove);
       $(document).off('mouseup', handleEnd);
@@ -81,7 +84,6 @@ function MoveCanvas(events, canvas) {
       var position = getPosition(event);
 
       context = {
-        viewbox: canvas.viewbox(),
         start: position
       };
 
diff --git a/lib/features/touch/TouchInteraction.js b/lib/features/touch/TouchInteraction.js
new file mode 100644
index 00000000..7ecb0301
--- /dev/null
+++ b/lib/features/touch/TouchInteraction.js
@@ -0,0 +1,172 @@
+'use strict';
+
+var $ = require('jquery');
+var _ = require('lodash');
+
+function TouchInteraction(eventBus, canvas) {
+
+  var RANGE = { min: 0.2, max: 4 };
+
+  function cap(scale) {
+    return Math.max(RANGE.min, Math.min(RANGE.max, scale));
+  }
+
+  function zoom(pinchRatio, position) {
+    canvas.zoom(cap(pinchRatio), position);
+  }
+
+  function euclideanDistance(touch1, touch2) {
+    var dist =
+      Math.sqrt(
+          (touch1.clientX - touch2.clientX) *
+          (touch1.clientX - touch2.clientX) +
+          (touch1.clientY - touch2.clientY) *
+          (touch1.clientY - touch2.clientY)
+      );
+
+    return dist;
+  }
+
+  function init(element) {
+
+    function contextInit() {
+      context = {
+        start: {}
+      };
+    }
+
+    var context;
+    contextInit();
+
+    function handleTouchMove(event) {
+      var orgEvent = event.originalEvent;
+      var cX = 0;
+      var cY = 0;
+      var mX = 0;
+      var mY = 0;
+
+      if (context.move && !context.scale) {
+
+        _.forEach(orgEvent.changedTouches, function (touch) {
+          if (touch.identifier === context.moveId) {
+            cX = touch.clientX;
+            cY = touch.clientY;
+          }
+        });
+
+        if (!context.lasttouch.cX) {
+          context.lasttouch.cX = cX;
+        }
+
+        if (!context.lasttouch.cY) {
+          context.lasttouch.cY = cY;
+        }
+
+        mX = cX - context.lasttouch.cX;
+        mY = cY - context.lasttouch.cY;
+
+        canvas.scroll({
+          dx: mX,
+          dy: mY
+        });
+
+        context.lasttouch.cX = cX;
+        context.lasttouch.cY = cY;
+      }
+
+      if (context.scale) {
+        var dist = euclideanDistance(orgEvent.touches[0], orgEvent.touches[1]);
+        var distRatio = dist / context.start.dist;
+
+        zoom(distRatio * context.start.zoom, context.start.mid);
+        context.lastDistance = dist;
+      }
+
+      // prevent select
+      event.preventDefault();
+    }
+
+    function handleTouchEnd(event) {
+
+      var orgEvent = event.originalEvent;
+
+      if (orgEvent.touches.length < 1) {
+        contextInit();
+      }
+      if (orgEvent.touches.length === 1) {
+        initMove(orgEvent);
+      }
+      if (orgEvent.touches.length === 2) {
+        initScale(orgEvent);
+      }
+
+      _.forEach(orgEvent.changedTouches, function (touch) {
+        delete context[touch.identifier];
+      });
+
+      // prevent select
+      event.preventDefault();
+    }
+
+    function initMove(orgEvent) {
+      context.move = true;
+      context.moveId = orgEvent.touches[0].identifier;
+      context.scale = false;
+      if (!context.lasttouch) {
+        context.lasttouch = {
+          cX: undefined,
+          cY: undefined,
+          mX: 0,
+          mY: 0
+        };
+      }
+    }
+
+    function initScale(orgEvent) {
+      context.scale = true;
+      context.start.dist = euclideanDistance(orgEvent.touches[0], orgEvent.touches[1]);
+      context.lastDistance = context.start.dist;
+      context.start.zoom = canvas.zoom();
+      context.start.mid = {
+        x: (orgEvent.touches[0].clientX + orgEvent.touches[1].clientX) / 2,
+        y: (orgEvent.touches[0].clientY + orgEvent.touches[1].clientY) / 2
+      };
+    }
+
+    function handleTouchStart(event) {
+
+      var orgEvent = event.originalEvent;
+
+      _.forEach(orgEvent.changedTouches, function (touch) {
+        context.start[touch.identifier] = touch;
+      });
+
+      if (orgEvent.touches.length === 1) {
+        initMove(orgEvent);
+      }
+
+      if (orgEvent.touches.length === 2) {
+        initScale(orgEvent);
+      }
+
+      //Stop all interaction for more than 2 touch sources
+      if (orgEvent.touches.length > 2) {
+        contextInit();
+      }
+
+      event.preventDefault();
+    }
+
+    $(element).on('touchstart', handleTouchStart);
+    $(element).on('touchmove', handleTouchMove);
+    $(document).on('touchend', handleTouchEnd);
+  }
+
+  eventBus.on('canvas.init', function(e) {
+    init(e.paper.node);
+  });
+}
+
+TouchInteraction.$inject = ['eventBus', 'canvas'];
+
+module.exports = TouchInteraction;
\ No newline at end of file
diff --git a/lib/features/touch/index.js b/lib/features/touch/index.js
new file mode 100644
index 00000000..86309fa9
--- /dev/null
+++ b/lib/features/touch/index.js
@@ -0,0 +1,4 @@
+module.exports = {
+  __init__: [ 'touchInteraction' ],
+  touchInteraction: [ 'type', require('./TouchInteraction') ]
+};
\ No newline at end of file
diff --git a/lib/features/zoomscroll/ZoomScroll.js b/lib/features/zoomscroll/ZoomScroll.js
index d5bdb4fd..3f774706 100644
--- a/lib/features/zoomscroll/ZoomScroll.js
+++ b/lib/features/zoomscroll/ZoomScroll.js
@@ -51,6 +51,7 @@ function ZoomScroll(events, canvas) {
 
         canvas.scroll(delta);
       } else {
+        // zoom in relative to diagram {x,y} coordinates
         zoom(y, { x: event.offsetX, y: event.offsetY });
       }
 
diff --git a/test/spec/browser/ViewerSpec.js b/test/spec/browser/ViewerSpec.js
index b7271eaf..1b912514 100644
--- a/test/spec/browser/ViewerSpec.js
+++ b/test/spec/browser/ViewerSpec.js
@@ -127,6 +127,7 @@ describe('viewer', function() {
 
           // expect header to be written only once
           expect(svg.indexOf('<svg width="100%" height="100%">')).toBe(-1);
+          expect(svg.indexOf('<g class="viewport"')).toBe(-1);
 
           done();
         });
diff --git a/test/spec/browser/features/touch/TouchInteractionSpec.js b/test/spec/browser/features/touch/TouchInteractionSpec.js
new file mode 100644
index 00000000..feca5e7e
--- /dev/null
+++ b/test/spec/browser/features/touch/TouchInteractionSpec.js
@@ -0,0 +1,37 @@
+'use strict';
+
+var Matchers = require('../../../Matchers'),
+    TestHelper = require('../../../TestHelper');
+
+/* global bootstrapBpmnJS, inject */
+
+
+var fs = require('fs');
+
+var $ = require('jquery');
+
+
+var touchModule = require('../../../../../lib/features/touch'),
+    bpmnModule = require('../../../../../lib/core');
+
+
+describe('features - touch', function() {
+
+  beforeEach(Matchers.add);
+
+
+  var diagramXML = fs.readFileSync('test/fixtures/bpmn/complex.bpmn', 'utf-8');
+
+  var testModules = [ touchModule, bpmnModule ];
+
+  beforeEach(bootstrapBpmnJS(diagramXML, { modules: testModules }));
+
+
+  describe('bootstrap', function() {
+
+    it('should bootstrap', inject(function(touchInteraction) {
+      expect(touchInteraction).not.toBe(null);
+    }));
+
+  });
+});
\ No newline at end of file
diff --git a/test/spec/browser/features/zoomscoll/ZoomScrollSpec.js b/test/spec/browser/features/zoomscoll/ZoomScrollSpec.js
index ef020389..2ebd1a81 100644
--- a/test/spec/browser/features/zoomscoll/ZoomScrollSpec.js
+++ b/test/spec/browser/features/zoomscoll/ZoomScrollSpec.js
@@ -29,7 +29,7 @@ describe('features - zoomscroll', function() {
 
   describe('bootstrap', function() {
 
-    iit('should bootstrap', inject(function(zoomScroll) {
+    it('should bootstrap', inject(function(zoomScroll) {
       expect(zoomScroll).not.toBe(null);
     }));