gecko-dev/mobile/xul/chrome/content/input.js

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JavaScript

// -*- Mode: js2; tab-width: 2; indent-tabs-mode: nil; js2-basic-offset: 2; js2-skip-preprocessor-directives: t; js2-strict-trailing-comma-warning: nil -*-
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
Components.utils.import("resource://gre/modules/Geometry.jsm");
// Maximum delay in ms between the two taps of a double-tap
const kDoubleClickInterval = 400;
// Maximum distance in inches between the taps of a double-tap
const kDoubleClickRadius = 0.4;
// Amount of time to wait before tap is generate a mousemove
const kOverTapWait = 150;
// Amount of time to wait before tap becomes long tap
const kLongTapWait = 500;
// maximum drag distance in inches while axis locking can still be reverted
const kAxisLockRevertThreshold = 0.8;
// Same as NS_EVENT_STATE_ACTIVE from nsIEventStateManager.h
const kStateActive = 0x00000001;
// After a drag begins, kinetic panning is stopped if the drag doesn't become
// a pan in 300 milliseconds.
const kStopKineticPanOnDragTimeout = 300;
// Min/max velocity of kinetic panning. This is in pixels/millisecond.
const kMinVelocity = 0.4;
const kMaxVelocity = 6;
/**
* MouseModule
*
* Handles all touch-related input such as dragging and tapping.
*
* The Fennec chrome DOM tree has elements that are augmented dynamically with
* custom JS properties that tell the MouseModule they have custom support for
* either dragging or clicking. These JS properties are JS objects that expose
* an interface supporting dragging or clicking (though currently we only look
* to drag scrollable elements).
*
* A custom dragger is a JS property that lives on a scrollable DOM element,
* accessible as myElement.customDragger. The customDragger must support the
* following interface: (The `scroller' argument is given for convenience, and
* is the object reference to the element's scrollbox object).
*
* dragStart(cX, cY, target, scroller)
* Signals the beginning of a drag. Coordinates are passed as
* client coordinates. target is copied from the event.
*
* dragStop(dx, dy, scroller)
* Signals the end of a drag. The dx, dy parameters may be non-zero to
* indicate one last drag movement.
*
* dragMove(dx, dy, scroller, isKinetic)
* Signals an input attempt to drag by dx, dy.
*
* There is a default dragger in case a scrollable element is dragged --- see
* the defaultDragger prototype property.
*/
function MouseModule() {
this._dragData = new DragData();
this._dragger = null;
this._inputField = null;
this._downUpEvents = [];
this._targetScrollbox = null;
this._targetScrollInterface = null;
this._suppressNextMouseUp = false;
this._kinetic = new KineticController(this._dragBy.bind(this),
this._kineticStop.bind(this));
this._singleClickTimeout = new Util.Timeout(this._doSingleClick.bind(this));
this._mouseOverTimeout = new Util.Timeout(this._doMouseOver.bind(this));
this._longClickTimeout = new Util.Timeout(this._doLongClick.bind(this));
this._doubleClickRadius = Util.displayDPI * kDoubleClickRadius;
window.addEventListener("mousedown", this, true);
window.addEventListener("mouseup", this, true);
window.addEventListener("mousemove", this, true);
window.addEventListener("contextmenu", this, false);
window.addEventListener("CancelTouchSequence", this, true);
}
MouseModule.prototype = {
_initMouseEventFromEvent: function _initMouseEventFromEvent(aDestEvent, aSrcEvent, aType, aCanBubble, aCancellable) {
aDestEvent.initMouseEvent(aType, aCanBubble, aCancellable, window, aSrcEvent.detail,
aSrcEvent.screenX, aSrcEvent.screenY, aSrcEvent.clientX, aSrcEvent.clientY,
aSrcEvent.ctrlKey, aSrcEvent.altKey, aSrcEvent.shiftKey, aSrcEvent.metaKey,
aSrcEvent.button, aSrcEvent.relatedTarget);
},
handleEvent: function handleEvent(aEvent) {
switch (aEvent.type) {
case "contextmenu":
// bug 598965 - chrome UI should should stop to be pannable once the
// context menu has appeared
if (ContextHelper.popupState)
this.cancelPending();
break;
case "CancelTouchSequence":
this.cancelPending();
break;
default: {
// Filter out mouse events that aren't first button
if (aEvent.button !== 0)
break;
switch (aEvent.type) {
case "mousedown":
this._onMouseDown(aEvent);
break;
case "mousemove":
aEvent.stopPropagation();
aEvent.preventDefault();
this._onMouseMove(aEvent);
break;
case "mouseup":
this._onMouseUp(aEvent);
break;
case "click":
aEvent.stopPropagation();
aEvent.preventDefault();
aEvent.target.removeEventListener("click", this, true);
break;
}
}
}
},
sample: function sample(aTimeStamp) {
this._waitingForPaint = false;
},
/**
* This gets invoked by the input handler if another module grabs. We should
* reset our state or something here. This is probably doing the wrong thing
* in its current form.
*/
cancelPending: function cancelPending() {
this._doDragStop();
// Kinetic panning may have already been active or drag stop above may have
// made kinetic panning active.
this._kinetic.end();
this._targetScrollbox = null;
this._targetScrollInterface = null;
this._inputField = null;
this._cleanClickBuffer();
},
/** Begin possible pan and send tap down event. */
_onMouseDown: function _onMouseDown(aEvent) {
let dragData = this._dragData;
if (dragData.dragging) {
// Somehow a mouse up was missed.
this._doDragStop();
}
dragData.reset();
this.dX = 0;
this.dY = 0;
// walk up the DOM tree in search of nearest scrollable ancestor. nulls are
// returned if none found.
let [targetScrollbox, targetScrollInterface, dragger]
= ScrollUtils.getScrollboxFromElement(aEvent.originalTarget);
// stop kinetic panning if targetScrollbox has changed
if (this._kinetic.isActive() && this._dragger != dragger)
this._kinetic.end();
this._targetScrollbox = targetScrollInterface ? targetScrollInterface.element : targetScrollbox;
this._targetScrollInterface = targetScrollInterface;
// Do tap
if (!this._kinetic.isActive()) {
let event = document.createEvent("MouseEvent");
this._initMouseEventFromEvent(event, aEvent, "TapDown", true, true);
let success = aEvent.target.dispatchEvent(event);
if (success) {
this._recordEvent(aEvent);
this._target = aEvent.target;
this._mouseOverTimeout.once(kOverTapWait);
this._longClickTimeout.once(kLongTapWait);
} else {
// cancel all pending content clicks
this._cleanClickBuffer();
}
}
// Do pan
if (dragger) {
let draggable = dragger.isDraggable(targetScrollbox, targetScrollInterface);
dragData.locked = !draggable.x || !draggable.y;
if (draggable.x || draggable.y) {
this._dragger = dragger;
this._doDragStart(aEvent, draggable);
}
}
// When panning starts over an input field, focus should not change
let inputField = this._getTargetInputField(aEvent.originalTarget);
if (inputField && this._dragger) {
this._inputField = inputField;
aEvent.preventDefault();
aEvent.stopPropagation();
}
},
/** Send tap up event and any necessary full taps. */
_onMouseUp: function _onMouseUp(aEvent) {
if (this._suppressNextMouseUp) {
this._suppressNextMouseUp = false;
aEvent.stopPropagation();
aEvent.preventDefault();
}
// onMouseMove will not record the delta change if we are waiting for a
// paint. Since this is the last input for this drag, we override the flag.
this._waitingForPaint = false;
this._onMouseMove(aEvent);
let dragData = this._dragData;
this._doDragStop();
// Do tap
if (this._target) {
let isClick = dragData.isClick();
let event = document.createEvent("MouseEvents");
this._initMouseEventFromEvent(event, aEvent, "TapUp", true, true);
event.isClick = isClick;
let success = aEvent.target.dispatchEvent(event);
if (!success) {
this._cleanClickBuffer();
} else {
this._recordEvent(aEvent);
let commitToClicker = isClick && (this._downUpEvents.length > 1);
if (commitToClicker)
// commit this click to the doubleclick timewait buffer
this._commitAnotherClick();
else
// clean the click buffer ourselves
this._cleanClickBuffer();
}
}
this._mouseOverTimeout.clear();
this._longClickTimeout.clear();
this._target = null;
// Do pan
if (dragData.isPan() && this._dragger) {
// User was panning around, do not allow click
let generatesClick = aEvent.detail;
if (generatesClick)
aEvent.target.addEventListener("click", this, true);
}
// Move the caret to the end of the target input field and focus it
if (this._inputField && !this._dragData.isPan()) {
let inputField = this._inputField;
let textLength = inputField.textLength;
inputField.setSelectionRange(textLength, textLength);
inputField.focus();
}
this._inputField = null;
},
/**
* If we're in a drag, do what we have to do to drag on.
*/
_onMouseMove: function _onMouseMove(aEvent) {
let dragData = this._dragData;
if (dragData.dragging) {
let oldIsPan = dragData.isPan();
dragData.setDragPosition(aEvent.screenX, aEvent.screenY);
// Kinetic panning is sensitive to time. It is more stable if it receives
// the mousemove events as they come. For dragging though, we only want
// to call _dragBy if we aren't waiting for a paint (so we don't spam the
// main browser loop with a bunch of redundant paints).
//
// Here, we feed kinetic panning drag differences for mouse events as
// come; for dragging, we build up a drag buffer in this.dX/this.dY and
// release it when we are ready to paint.
//
let [sX, sY] = dragData.panPosition();
this.dX += dragData.prevPanX - sX;
this.dY += dragData.prevPanY - sY;
if (dragData.isPan()) {
this.sendMove(aEvent);
// Only pan when mouse event isn't part of a click. Prevent jittering on tap.
this._kinetic.addData(sX - dragData.prevPanX, sY - dragData.prevPanY);
// dragBy will reset dX and dY values to 0
this._dragBy(this.dX, this.dY);
// Let everyone know when mousemove begins a pan
if (!oldIsPan && dragData.isPan()) {
this._mouseOverTimeout.clear();
this._longClickTimeout.clear();
let event = document.createEvent("Events");
event.initEvent("PanBegin", true, false);
this._targetScrollbox.dispatchEvent(event);
}
}
}
else if (!dragData.dragging && this._downUpEvents.length) {
let oldEvent = this._downUpEvents[0];
dragData._isPan = ScrollUtils.isPan(new Point(oldEvent.clientX, oldEvent.clientY),
new Point(aEvent.clientX, aEvent.clientY));
if (dragData.isPan())
this._longClickTimeout.clear();
}
},
sendMove: function(aEvent) {
let event = document.createEvent("MouseEvents");
this._initMouseEventFromEvent(event, aEvent, "TapMove", true, true);
aEvent.target.dispatchEvent(event);
},
/**
* Inform our dragger of a dragStart.
*/
_doDragStart: function _doDragStart(aEvent, aDraggable) {
let dragData = this._dragData;
dragData.setDragStart(aEvent.screenX, aEvent.screenY, aDraggable);
this._kinetic.addData(0, 0);
this._dragStartTime = Date.now();
if (!this._kinetic.isActive())
this._dragger.dragStart(aEvent.clientX, aEvent.clientY, aEvent.target, this._targetScrollInterface);
},
/** Finish a drag. */
_doDragStop: function _doDragStop() {
let dragData = this._dragData;
if (!dragData.dragging)
return;
dragData.endDrag();
// Note: it is possible for kinetic scrolling to be active from a
// mousedown/mouseup event previous to this one. In this case, we
// want the kinetic panner to tell our drag interface to stop.
if (dragData.isPan()) {
if (Date.now() - this._dragStartTime > kStopKineticPanOnDragTimeout)
this._kinetic._velocity.set(0, 0);
// Start kinetic pan.
this._kinetic.start();
} else {
this._kinetic.end();
this._dragger.dragStop(0, 0, this._targetScrollInterface);
this._dragger = null;
}
},
/**
* Used by _onMouseMove() above and by KineticController's timer to do the
* actual dragMove signalling to the dragger. We'd put this in _onMouseMove()
* but then KineticController would be adding to its own data as it signals
* the dragger of dragMove()s.
*/
_dragBy: function _dragBy(dX, dY, aIsKinetic) {
let dragged = true;
let dragData = this._dragData;
if (!this._waitingForPaint || aIsKinetic) {
let dragData = this._dragData;
dragged = this._dragger.dragMove(dX, dY, this._targetScrollInterface, aIsKinetic);
if (dragged && !this._waitingForPaint) {
this._waitingForPaint = true;
mozRequestAnimationFrame(this);
}
this.dX = 0;
this.dY = 0;
}
if (!dragData.isPan())
this._kinetic.pause();
return dragged;
},
/** Callback for kinetic scroller. */
_kineticStop: function _kineticStop() {
// Kinetic panning could finish while user is panning, so don't finish
// the pan just yet.
let dragData = this._dragData;
if (!dragData.dragging) {
this._dragger.dragStop(0, 0, this._targetScrollInterface);
this._dragger = null;
let event = document.createEvent("Events");
event.initEvent("PanFinished", true, false);
this._targetScrollbox.dispatchEvent(event);
}
},
/** Called when tap down times is long enought to generate a mousemove **/
_doMouseOver: function _doMouseOver() {
let ev = this._downUpEvents[0];
this._dispatchTap("TapOver", ev);
},
/** Called when tap down times out and becomes a long tap. */
_doLongClick: function _doLongClick() {
let ev = this._downUpEvents[0];
this._suppressNextMouseUp = true;
this._dispatchTap("TapLong", ev);
},
/**
* Commit another click event to our click buffer. The `click buffer' is a
* timeout initiated by the first click. If the timeout is still alive when
* another click is committed, then the click buffer forms a double tap, and
* the timeout is cancelled. Otherwise, the timeout issues a single tap.
*/
_commitAnotherClick: function _commitAnotherClick() {
if (this._singleClickTimeout.isPending()) { // we're waiting for a second click for double
this._singleClickTimeout.clear();
this._doDoubleClick();
} else {
this._singleClickTimeout.once(kDoubleClickInterval);
}
},
/** Endpoint of _commitAnotherClick(). Finalize a single tap. */
_doSingleClick: function _doSingleClick() {
let mouseUp = this._downUpEvents[1];
this._cleanClickBuffer();
this._dispatchTap("TapSingle", mouseUp);
},
/** Endpoint of _commitAnotherClick(). Finalize a double tap. */
_doDoubleClick: function _doDoubleClick() {
let mouseUp1 = this._downUpEvents[1];
// sometimes the second press event is not dispatched at all
let mouseUp2 = this._downUpEvents[Math.min(3, this._downUpEvents.length - 1)];
this._cleanClickBuffer();
let dx = mouseUp1.clientX - mouseUp2.clientX;
let dy = mouseUp1.clientY - mouseUp2.clientY;
let radius = this._doubleClickRadius;
if (dx*dx + dy*dy < radius*radius) {
this._dispatchTap("TapDouble", mouseUp1);
} else {
this._dispatchTap("TapSingle", mouseUp1);
this._dispatchTap("TapSingle", mouseUp2);
}
},
_dispatchTap: function _dispatchTap(aType, aMouseEvent) {
let event = document.createEvent("Events");
event.initEvent(aType, true, false);
event.clientX = aMouseEvent.clientX;
event.clientY = aMouseEvent.clientY;
event.modifiers = Util.modifierMaskFromEvent(aMouseEvent);
aMouseEvent.originalTarget.dispatchEvent(event);
},
/**
* Record a mousedown/mouseup event for later redispatch via
* _redispatchDownUpEvents()
*/
_recordEvent: function _recordEvent(aEvent) {
this._downUpEvents.push(aEvent);
},
/**
* Clean out the click buffer. Should be called after a single, double, or
* non-click has been processed and all relevant (re)dispatches of events in
* the recorded down/up event queue have been issued out.
*/
_cleanClickBuffer: function _cleanClickBuffer() {
this._singleClickTimeout.clear();
this._mouseOverTimeout.clear();
this._longClickTimeout.clear();
this._downUpEvents.splice(0, this._downUpEvents.length);
},
/* XXXvn this can potentially be moved into ScrollUtils */
_getTargetInputField: function _getTargetInputField(aTarget) {
let focusedElement = document.commandDispatcher.focusedElement;
let parentNode = aTarget.parentNode;
let inputField = null;
if (aTarget.mozIsTextField && aTarget.mozIsTextField(false) && focusedElement != aTarget)
inputField = aEventTarget;
else if (parentNode.mozIsTextField && parentNode.mozIsTextField(false) && focusedElement != parentNode)
inputField = parentNode;
else if (aTarget instanceof XULElement && aTarget.inputField)
inputField = aTarget.inputField;
return inputField;
},
toString: function toString() {
return '[MouseModule] {'
+ '\n\tdragData=' + this._dragData + ', '
+ 'dragger=' + this._dragger + ', '
+ '\n\tdownUpEvents=' + this._downUpEvents + ', '
+ 'length=' + this._downUpEvents.length + ', '
+ '\n\ttargetScroller=' + this._targetScrollInterface + '}';
}
};
var ScrollUtils = {
// threshold in pixels for sensing a tap as opposed to a pan
get tapRadius() {
let dpi = Util.displayDPI;
delete this.tapRadius;
return this.tapRadius = Services.prefs.getIntPref("ui.dragThresholdX") / 240 * dpi;
},
/**
* Walk up (parentward) the DOM tree from elem in search of a scrollable element.
* Return the element and its scroll interface if one is found, two nulls otherwise.
*
* This function will cache the pointer to the scroll interface on the element itself,
* so it is safe to call it many times without incurring the same XPConnect overhead
* as in the initial call.
*/
getScrollboxFromElement: function getScrollboxFromElement(elem) {
let scrollbox = null;
let qinterface = null;
for (; elem; elem = elem.parentNode) {
try {
if (elem.scrollBoxObject) {
scrollbox = elem;
qinterface = elem.scrollBoxObject;
break;
} else if (elem.customDragger) {
scrollbox = elem;
break;
} else if (elem.boxObject) {
let qi = (elem._cachedSBO) ? elem._cachedSBO
: elem.boxObject.QueryInterface(Ci.nsIScrollBoxObject);
if (qi) {
scrollbox = elem;
scrollbox._cachedSBO = qinterface = qi;
break;
}
}
} catch (e) { /* we aren't here to deal with your exceptions, we'll just keep
traversing until we find something more well-behaved, as we
prefer default behaviour to whiny scrollers. */ }
}
return [scrollbox, qinterface, (scrollbox ? (scrollbox.customDragger || this._defaultDragger) : null)];
},
/** Determine if the distance moved can be considered a pan */
isPan: function isPan(aPoint, aPoint2) {
return (Math.abs(aPoint.x - aPoint2.x) > this.tapRadius ||
Math.abs(aPoint.y - aPoint2.y) > this.tapRadius);
},
/**
* The default dragger object used by MouseModule when dragging a scrollable
* element that provides no customDragger. Simply performs the expected
* regular scrollBy calls on the scroller.
*/
_defaultDragger: {
isDraggable: function isDraggable(target, scroller) {
let sX = {}, sY = {},
pX = {}, pY = {};
scroller.getPosition(pX, pY);
scroller.getScrolledSize(sX, sY);
let rect = target.getBoundingClientRect();
return { x: (sX.value > rect.width || pX.value != 0),
y: (sY.value > rect.height || pY.value != 0) };
},
dragStart: function dragStart(cx, cy, target, scroller) {
scroller.element.addEventListener("PanBegin", this._showScrollbars, false);
},
dragStop: function dragStop(dx, dy, scroller) {
scroller.element.removeEventListener("PanBegin", this._showScrollbars, false);
return this.dragMove(dx, dy, scroller);
},
dragMove: function dragMove(dx, dy, scroller) {
if (scroller.getPosition) {
try {
let oldX = {}, oldY = {};
scroller.getPosition(oldX, oldY);
scroller.scrollBy(dx, dy);
let newX = {}, newY = {};
scroller.getPosition(newX, newY);
return (newX.value != oldX.value) || (newY.value != oldY.value);
} catch (e) { /* we have no time for whiny scrollers! */ }
}
return false;
},
_showScrollbars: function _showScrollbars(aEvent) {
let scrollbox = aEvent.target;
scrollbox.setAttribute("panning", "true");
let hideScrollbars = function() {
scrollbox.removeEventListener("PanFinished", hideScrollbars, false);
scrollbox.removeEventListener("CancelTouchSequence", hideScrollbars, false);
scrollbox.removeAttribute("panning");
}
// Wait for panning to be completely finished before removing scrollbars
scrollbox.addEventListener("PanFinished", hideScrollbars, false);
scrollbox.addEventListener("CancelTouchSequence", hideScrollbars, false);
}
}
};
/**
* DragData handles processing drags on the screen, handling both
* locking of movement on one axis, and click detection.
*/
function DragData() {
this._domUtils = Cc["@mozilla.org/inspector/dom-utils;1"].getService(Ci.inIDOMUtils);
this._lockRevertThreshold = Util.displayDPI * kAxisLockRevertThreshold;
this.reset();
};
DragData.prototype = {
reset: function reset() {
this.dragging = false;
this.sX = null;
this.sY = null;
this.locked = false;
this.stayLocked = false;
this.lockedX = null;
this.lockedY = null;
this._originX = null;
this._originY = null;
this.prevPanX = null;
this.prevPanY = null;
this._isPan = false;
},
/** Depending on drag data, locks sX,sY to X-axis or Y-axis of start position. */
_lockAxis: function _lockAxis(sX, sY) {
if (this.locked) {
if (this.lockedX !== null)
sX = this.lockedX;
else if (this.lockedY !== null)
sY = this.lockedY;
return [sX, sY];
}
else {
return [this._originX, this._originY];
}
},
setDragPosition: function setDragPosition(sX, sY) {
// Check if drag is now a pan.
if (!this._isPan) {
this._isPan = ScrollUtils.isPan(new Point(this._originX, this._originY), new Point(sX, sY));
if (this._isPan)
this._resetActive();
}
// If now a pan, mark previous position where panning was.
if (this._isPan) {
let absX = Math.abs(this._originX - sX);
let absY = Math.abs(this._originY - sY);
if (absX > this._lockRevertThreshold || absY > this._lockRevertThreshold)
this.stayLocked = true;
// After the first lock, see if locking decision should be reverted.
if (!this.stayLocked) {
if (this.lockedX && absX > 3 * absY)
this.lockedX = null;
else if (this.lockedY && absY > 3 * absX)
this.lockedY = null;
}
if (!this.locked) {
// look at difference from origin coord to lock movement, but only
// do it if initial movement is sufficient to detect intent
// divide possibilty space into eight parts. Diagonals will allow
// free movement, while moving towards a cardinal will lock that
// axis. We pick a direction if you move more than twice as far
// on one axis than another, which should be an angle of about 30
// degrees from the axis
if (absX > 2.5 * absY)
this.lockedY = sY;
else if (absY > absX)
this.lockedX = sX;
this.locked = true;
}
}
// After pan lock, figure out previous panning position. Base it on last drag
// position so there isn't a jump in panning.
let [prevX, prevY] = this._lockAxis(this.sX, this.sY);
this.prevPanX = prevX;
this.prevPanY = prevY;
this.sX = sX;
this.sY = sY;
},
setDragStart: function setDragStart(screenX, screenY, aDraggable) {
this.sX = this._originX = screenX;
this.sY = this._originY = screenY;
this.dragging = true;
// If the target area is pannable only in one direction lock it early
// on the right axis
this.lockedX = !aDraggable.x ? screenX : null;
this.lockedY = !aDraggable.y ? screenY : null;
this.stayLocked = this.lockedX || this.lockedY;
this.locked = this.stayLocked;
},
endDrag: function endDrag() {
this._resetActive();
this.dragging = false;
},
/** Returns true if drag should pan scrollboxes.*/
isPan: function isPan() {
return this._isPan;
},
/** Return true if drag should be parsed as a click. */
isClick: function isClick() {
return !this._isPan;
},
/**
* Returns the screen position for a pan. This factors in axis locking.
* @return Array of screen X and Y coordinates
*/
panPosition: function panPosition() {
return this._lockAxis(this.sX, this.sY);
},
_resetActive: function _resetActive() {
// dismiss the active state of the pan element
let target = document.documentElement;
let state = this._domUtils.getContentState(target);
this._domUtils.setContentState(target, state & kStateActive);
},
toString: function toString() {
return '[DragData] { sX,sY=' + this.sX + ',' + this.sY + ', dragging=' + this.dragging + ' }';
}
};
/**
* KineticController - a class to take drag position data and use it
* to do kinetic panning of a scrollable object.
*
* aPanBy is a function that will be called with the dx and dy
* generated by the kinetic algorithm. It should return true if the
* object was panned, false if there was no movement.
*
* There are two complicated things done here. One is calculating the
* initial velocity of the movement based on user input. Two is
* calculating the distance to move every frame.
*/
function KineticController(aPanBy, aEndCallback) {
this._panBy = aPanBy;
this._beforeEnd = aEndCallback;
// These are used to calculate the position of the scroll panes during kinetic panning. Think of
// these points as vectors that are added together and multiplied by scalars.
this._position = new Point(0, 0);
this._velocity = new Point(0, 0);
this._acceleration = new Point(0, 0);
this._time = 0;
this._timeStart = 0;
// How often do we change the position of the scroll pane? Too often and panning may jerk near
// the end. Too little and panning will be choppy. In milliseconds.
this._updateInterval = Services.prefs.getIntPref("browser.ui.kinetic.updateInterval");
// Constants that affect the "friction" of the scroll pane.
this._exponentialC = Services.prefs.getIntPref("browser.ui.kinetic.exponentialC");
this._polynomialC = Services.prefs.getIntPref("browser.ui.kinetic.polynomialC") / 1000000;
// Number of milliseconds that can contain a swipe. Movements earlier than this are disregarded.
this._swipeLength = Services.prefs.getIntPref("browser.ui.kinetic.swipeLength");
this._reset();
}
KineticController.prototype = {
_reset: function _reset() {
this._active = false;
this._paused = false;
this.momentumBuffer = [];
this._velocity.set(0, 0);
},
isActive: function isActive() {
return this._active;
},
_startTimer: function _startTimer() {
let self = this;
let lastp = this._position; // track last position vector because pan takes deltas
let v0 = this._velocity; // initial velocity
let a = this._acceleration; // acceleration
let c = this._exponentialC;
let p = new Point(0, 0);
let dx, dy, t, realt;
function calcP(v0, a, t) {
// Important traits for this function:
// p(t=0) is 0
// p'(t=0) is v0
//
// We use exponential to get a smoother stop, but by itself exponential
// is too smooth at the end. Adding a polynomial with the appropriate
// weight helps to balance
return v0 * Math.exp(-t / c) * -c + a * t * t + v0 * c;
}
this._calcV = function(v0, a, t) {
return v0 * Math.exp(-t / c) + 2 * a * t;
}
let callback = {
sample: function kineticHandleEvent(timeStamp) {
// Someone called end() on us between timer intervals
// or we are paused.
if (!self.isActive() || self._paused)
return;
// To make animation end fast enough but to keep smoothness, average the ideal
// time frame (smooth animation) with the actual time lapse (end fast enough).
// Animation will never take longer than 2 times the ideal length of time.
realt = timeStamp - self._initialTime;
self._time += self._updateInterval;
t = (self._time + realt) / 2;
// Calculate new position.
p.x = calcP(v0.x, a.x, t);
p.y = calcP(v0.y, a.y, t);
dx = Math.round(p.x - lastp.x);
dy = Math.round(p.y - lastp.y);
// Test to see if movement is finished for each component.
if (dx * a.x > 0) {
dx = 0;
lastp.x = 0;
v0.x = 0;
a.x = 0;
}
// Symmetric to above case.
if (dy * a.y > 0) {
dy = 0;
lastp.y = 0;
v0.y = 0;
a.y = 0;
}
if (v0.x == 0 && v0.y == 0) {
self.end();
} else {
let panStop = false;
if (dx != 0 || dy != 0) {
try { panStop = !self._panBy(-dx, -dy, true); } catch (e) {}
lastp.add(dx, dy);
}
if (panStop)
self.end();
else
mozRequestAnimationFrame(this);
}
}
};
this._active = true;
this._paused = false;
mozRequestAnimationFrame(callback);
},
start: function start() {
function sign(x) {
return x ? ((x > 0) ? 1 : -1) : 0;
}
function clampFromZero(x, closerToZero, furtherFromZero) {
if (x >= 0)
return Math.max(closerToZero, Math.min(furtherFromZero, x));
return Math.min(-closerToZero, Math.max(-furtherFromZero, x));
}
let mb = this.momentumBuffer;
let mblen = this.momentumBuffer.length;
let lastTime = mb[mblen - 1].t;
let distanceX = 0;
let distanceY = 0;
let swipeLength = this._swipeLength;
// determine speed based on recorded input
let me;
for (let i = 0; i < mblen; i++) {
me = mb[i];
if (lastTime - me.t < swipeLength) {
distanceX += me.dx;
distanceY += me.dy;
}
}
let currentVelocityX = 0;
let currentVelocityY = 0;
if (this.isActive()) {
// If active, then we expect this._calcV to be defined.
let currentTime = Date.now() - this._initialTime;
currentVelocityX = Util.clamp(this._calcV(this._velocity.x, this._acceleration.x, currentTime), -kMaxVelocity, kMaxVelocity);
currentVelocityY = Util.clamp(this._calcV(this._velocity.y, this._acceleration.y, currentTime), -kMaxVelocity, kMaxVelocity);
}
if (currentVelocityX * this._velocity.x <= 0)
currentVelocityX = 0;
if (currentVelocityY * this._velocity.y <= 0)
currentVelocityY = 0;
let swipeTime = Math.min(swipeLength, lastTime - mb[0].t);
this._velocity.x = clampFromZero((distanceX / swipeTime) + currentVelocityX, Math.abs(currentVelocityX), kMaxVelocity);
this._velocity.y = clampFromZero((distanceY / swipeTime) + currentVelocityY, Math.abs(currentVelocityY), kMaxVelocity);
if (Math.abs(this._velocity.x) < kMinVelocity)
this._velocity.x = 0;
if (Math.abs(this._velocity.y) < kMinVelocity)
this._velocity.y = 0;
// Set acceleration vector to opposite signs of velocity
this._acceleration.set(this._velocity.clone().map(sign).scale(-this._polynomialC));
this._position.set(0, 0);
this._initialTime = mozAnimationStartTime;
this._time = 0;
this.momentumBuffer = [];
if (!this.isActive() || this._paused)
this._startTimer();
return true;
},
pause: function pause() {
this._paused = true;
},
end: function end() {
if (this.isActive()) {
if (this._beforeEnd)
this._beforeEnd();
this._reset();
}
},
addData: function addData(dx, dy) {
let mbLength = this.momentumBuffer.length;
let now = Date.now();
if (this.isActive()) {
// Stop active movement when dragging in other direction.
if (dx * this._velocity.x < 0 || dy * this._velocity.y < 0)
this.end();
}
this.momentumBuffer.push({'t': now, 'dx' : dx, 'dy' : dy});
}
};
/**
* Input module for basic scrollwheel input. Currently just zooms the browser
* view accordingly.
*/
function ScrollwheelModule(container) {
container.addEventListener("DOMMouseScroll", this, true);
container.addEventListener("MozMousePixelScroll", this, true);
}
ScrollwheelModule.prototype = {
pendingEvent : 0,
handleEvent: function handleEvent(aEvent) {
if (aEvent.type == "DOMMouseScroll" || aEvent.type == "MozMousePixelScroll") {
/*
* If events come too fast we don't want their handling to lag the zoom in/zoom out execution.
* With the timeout the zoom is executed as we scroll.
*/
if (this.pendingEvent)
clearTimeout(this.pendingEvent);
this.pendingEvent = setTimeout(function handleEventImpl(self) {
self.pendingEvent = 0;
Browser.zoom(aEvent.detail);
}, 0, this);
aEvent.stopPropagation();
aEvent.preventDefault();
}
},
/* We don't have much state to reset if we lose event focus */
cancelPending: function cancelPending() {}
};
// Simple gestures support
//
// As per bug #412486, web content must not be allowed to receive any
// simple gesture events. Multi-touch gesture APIs are in their
// infancy and we do NOT want to be forced into supporting an API that
// will probably have to change in the future. (The current Mac OS X
// API is undocumented and was reverse-engineered.) Until support is
// implemented in the event dispatcher to keep these events as
// chrome-only, we must listen for the simple gesture events during
// the capturing phase and call stopPropagation on every event.
function GestureModule(aElement) {
aElement.addEventListener("MozSwipeGesture", this, true);
aElement.addEventListener("MozMagnifyGestureStart", this, true);
aElement.addEventListener("MozMagnifyGestureUpdate", this, true);
aElement.addEventListener("MozMagnifyGesture", this, true);
aElement.addEventListener("CancelTouchSequence", this, true);
}
GestureModule.prototype = {
/**
* Dispatch events based on the type of mouse gesture event. For now, make
* sure to stop propagation of every gesture event so that web content cannot
* receive gesture events.
*
* @param nsIDOMEvent information structure
*/
handleEvent: function handleEvent(aEvent) {
try {
let consume = false;
switch (aEvent.type) {
case "MozSwipeGesture":
// Cancel other touch sequence events, and be courteous by allowing them
// to say no.
let event = document.createEvent("Events");
event.initEvent("CancelTouchSequence", true, true);
let success = aEvent.target.dispatchEvent(event);
if (!success)
return;
let gesture = Ci.nsIDOMSimpleGestureEvent;
switch (aEvent.direction) {
case gesture.DIRECTION_UP:
Browser.scrollContentToBottom();
break;
case gesture.DIRECTION_DOWN:
Browser.scrollContentToTop();
break;
case gesture.DIRECTION_LEFT:
CommandUpdater.doCommand("cmd_forward");
break;
case gesture.DIRECTION_RIGHT:
CommandUpdater.doCommand("cmd_back");
break;
}
break;
case "MozMagnifyGestureStart":
consume = true;
this._pinchStart(aEvent);
break;
case "MozMagnifyGestureUpdate":
consume = true;
if (this._ignoreNextUpdate)
this._ignoreNextUpdate = false;
else
this._pinchUpdate(aEvent);
break;
case "MozMagnifyGesture":
consume = true;
this._pinchEnd(aEvent);
break;
case "CancelTouchSequence":
this.cancelPending();
break;
}
if (consume) {
// prevent sending of event to content
aEvent.stopPropagation();
aEvent.preventDefault();
}
}
catch (e) {
Util.dumpLn("Error while handling gesture event", aEvent.type,
"\nPlease report error at:", e);
Cu.reportError(e);
}
},
cancelPending: function cancelPending() {
if (AnimatedZoom.isZooming())
AnimatedZoom.finish();
},
_pinchStart: function _pinchStart(aEvent) {
if (AnimatedZoom.isZooming())
return;
// Cancel other touch sequence events, and be courteous by allowing them
// to say no.
let event = document.createEvent("Events");
event.initEvent("CancelTouchSequence", true, true);
let success = aEvent.target.dispatchEvent(event);
if (!success || !Browser.selectedTab.allowZoom)
return;
AnimatedZoom.start();
this._pinchDelta = 0;
this._ignoreNextUpdate = true; // first update gives useless, huge delta
// cache gesture limit values
this._maxGrowth = Services.prefs.getIntPref("browser.ui.pinch.maxGrowth");
this._maxShrink = Services.prefs.getIntPref("browser.ui.pinch.maxShrink");
this._scalingFactor = Services.prefs.getIntPref("browser.ui.pinch.scalingFactor");
// Adjust the client coordinates to be relative to the browser element's top left corner.
this._browserBCR = getBrowser().getBoundingClientRect();
this._pinchStartX = aEvent.clientX - this._browserBCR.left;
this._pinchStartY = aEvent.clientY - this._browserBCR.top;
},
_pinchUpdate: function _pinchUpdate(aEvent) {
if (!AnimatedZoom.isZooming() || !aEvent.delta)
return;
let delta = 0;
let browser = AnimatedZoom.browser;
let oldScale = browser.scale;
let bcr = this._browserBCR;
// Accumulate pinch delta. Small changes are just jitter.
this._pinchDelta += aEvent.delta;
if (Math.abs(this._pinchDelta) >= oldScale) {
delta = this._pinchDelta;
this._pinchDelta = 0;
}
// decrease the pinchDelta min/max values to limit zooming out/in speed
delta = Util.clamp(delta, -this._maxShrink, this._maxGrowth);
let newScale = Browser.selectedTab.clampZoomLevel(oldScale * (1 + delta / this._scalingFactor));
let startScale = AnimatedZoom.startScale;
let scaleRatio = startScale / newScale;
let cX = aEvent.clientX - bcr.left;
let cY = aEvent.clientY - bcr.top;
// Calculate the new zoom rect.
let rect = AnimatedZoom.zoomFrom.clone();
rect.translate(this._pinchStartX - cX + (1-scaleRatio) * cX * rect.width / bcr.width,
this._pinchStartY - cY + (1-scaleRatio) * cY * rect.height / bcr.height);
rect.width *= scaleRatio;
rect.height *= scaleRatio;
this.translateInside(rect, new Rect(0, 0, browser.contentDocumentWidth * startScale,
browser.contentDocumentHeight * startScale));
// redraw zoom canvas according to new zoom rect
AnimatedZoom.updateTo(rect);
},
_pinchEnd: function _pinchEnd(aEvent) {
if (AnimatedZoom.isZooming())
AnimatedZoom.finish();
},
/**
* Ensure r0 is inside r1, if possible. Preserves w, h.
* Same as Rect.prototype.translateInside except it aligns the top left
* instead of the bottom right if r0 is bigger than r1.
*/
translateInside: function translateInside(r0, r1) {
let offsetX = (r0.left < r1.left ? r1.left - r0.left :
(r0.right > r1.right ? Math.max(r1.left - r0.left, r1.right - r0.right) : 0));
let offsetY = (r0.top < r1.top ? r1.top - r0.top :
(r0.bottom > r1.bottom ? Math.max(r1.top - r0.top, r1.bottom - r0.bottom) : 0));
return r0.translate(offsetX, offsetY);
}
};