*/
Dygraph.Interaction.startTouch = function(event, g, context) {
event.preventDefault(); // touch browsers are all nice.
+ if (event.touches.length > 1) {
+ // If the user ever puts two fingers down, it's not a double tap.
+ context.startTimeForDoubleTapMs = null;
+ }
+
var touches = [];
for (var i = 0; i < event.touches.length; i++) {
var t = event.touches[i];
// This is just a swipe.
context.initialPinchCenter = touches[0];
context.touchDirections = { x: true, y: true };
- } else if (touches.length == 2) {
+ } 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 = {
* @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];
if (touches.length == 1) {
xScale = 1.0;
yScale = 1.0;
- } else if (touches.length == 2) {
+ } else if (touches.length >= 2) {
var initHalfWidth = (initialTouches[1].pageX - c_init.pageX);
xScale = (touches[1].pageX - c_now.pageX) / initHalfWidth;
xScale = Math.min(8, Math.max(0.125, xScale));
yScale = Math.min(8, Math.max(0.125, yScale));
+ var didZoom = false;
if (context.touchDirections.x) {
g.dateWindow_ = [
c_init.dataX - swipe.dataX + (context.initialRange.x[0] - c_init.dataX) / xScale,
c_init.dataX - swipe.dataX + (context.initialRange.x[1] - c_init.dataX) / xScale
];
+ didZoom = true;
}
if (context.touchDirections.y) {
c_init.dataY - swipe.dataY + (context.initialRange.y[0] - c_init.dataY) / yScale,
c_init.dataY - swipe.dataY + (context.initialRange.y[1] - c_init.dataY) / yScale
];
+ didZoom = true;
}
}
}
g.drawGraph_(false);
+
+ // We only call zoomCallback on zooms, not pans, to mirror desktop behavior.
+ if (didZoom && touches.length > 1 && g.attr_('zoomCallback')) {
+ var viewWindow = g.xAxisRange();
+ g.attr_("zoomCallback")(viewWindow[0], viewWindow[1], g.yAxisRanges());
+ }
};
/**
if (event.touches.length !== 0) {
// this is effectively a "reset"
Dygraph.Interaction.startTouch(event, g, context);
+ } else if (event.changedTouches.length == 1) {
+ // Could be part of a "double tap"
+ // The heuristic here is that it's a double-tap if the two touchend events
+ // occur within 500ms and within a 50x50 pixel box.
+ var now = new Date().getTime();
+ var t = event.changedTouches[0];
+ if (context.startTimeForDoubleTapMs &&
+ now - context.startTimeForDoubleTapMs < 500 &&
+ context.doubleTapX && Math.abs(context.doubleTapX - t.screenX) < 50 &&
+ context.doubleTapY && Math.abs(context.doubleTapY - t.screenY) < 50) {
+ g.resetZoom();
+ } else {
+ context.startTimeForDoubleTapMs = now;
+ context.doubleTapX = t.screenX;
+ context.doubleTapY = t.screenY;
+ }
}
};
if (event.altKey || event.shiftKey) {
return;
}
- // TODO(konigsberg): replace g.doUnzoom()_ with something that is
- // friendlier to public use.
- g.doUnzoom_();
+ g.resetZoom();
}
};