- if (regionWidth >= 10 && context.dragDirection == Dygraph.HORIZONTAL) {
- g.doZoomX_(Math.min(context.dragStartX, context.dragEndX),
- Math.max(context.dragStartX, context.dragEndX));
- } else if (regionHeight >= 10 && context.dragDirection == Dygraph.VERTICAL) {
- g.doZoomY_(Math.min(context.dragStartY, context.dragEndY),
- Math.max(context.dragStartY, context.dragEndY));
+ var touches = [];
+ for (var i = 0; i < event.touches.length; i++) {
+ var t = event.touches[i];
+ // we dispense with 'dragGetX_' because all touchBrowsers support pageX
+ touches.push({
+ pageX: t.pageX,
+ pageY: t.pageY,
+ dataX: g.toDataXCoord(t.pageX),
+ dataY: g.toDataYCoord(t.pageY)
+ // identifier: t.identifier
+ });
+ }
+ context.initialTouches = touches;
+
+ if (touches.length == 1) {
+ // This is just a swipe.
+ context.initialPinchCenter = touches[0];
+ context.touchDirections = { x: true, y: true };
+ } else if (touches.length >= 2) {
+ // It's become a pinch!
+ // In case there are 3+ touches, we ignore all but the "first" two.
+
+ // only screen coordinates can be averaged (data coords could be log scale).
+ context.initialPinchCenter = {
+ pageX: 0.5 * (touches[0].pageX + touches[1].pageX),
+ pageY: 0.5 * (touches[0].pageY + touches[1].pageY),
+
+ // TODO(danvk): remove
+ dataX: 0.5 * (touches[0].dataX + touches[1].dataX),
+ dataY: 0.5 * (touches[0].dataY + touches[1].dataY)
+ };
+
+ // Make pinches in a 45-degree swath around either axis 1-dimensional zooms.
+ var initialAngle = 180 / Math.PI * Math.atan2(
+ context.initialPinchCenter.pageY - touches[0].pageY,
+ touches[0].pageX - context.initialPinchCenter.pageX);
+
+ // use symmetry to get it into the first quadrant.
+ initialAngle = Math.abs(initialAngle);
+ if (initialAngle > 90) initialAngle = 90 - initialAngle;
+
+ context.touchDirections = {
+ x: (initialAngle < (90 - 45/2)),
+ y: (initialAngle > 45/2)
+ };
+ }
+
+ // save the full x & y ranges.
+ context.initialRange = {
+ x: g.xAxisRange(),
+ y: g.yAxisRange()
+ };
+};
+
+/**
+ * @private
+ */
+Dygraph.Interaction.moveTouch = function(event, g, context) {
+ // If the tap moves, then it's definitely not part of a double-tap.
+ context.startTimeForDoubleTapMs = null;
+
+ var i, touches = [];
+ for (i = 0; i < event.touches.length; i++) {
+ var t = event.touches[i];
+ touches.push({
+ pageX: t.pageX,
+ pageY: t.pageY
+ });
+ }
+ var initialTouches = context.initialTouches;
+
+ var c_now;
+
+ // old and new centers.
+ var c_init = context.initialPinchCenter;
+ if (touches.length == 1) {
+ c_now = touches[0];