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Diffstat (limited to 'src/ngMobile/directive/ngClick.js')
| -rw-r--r-- | src/ngMobile/directive/ngClick.js | 272 |
1 files changed, 0 insertions, 272 deletions
diff --git a/src/ngMobile/directive/ngClick.js b/src/ngMobile/directive/ngClick.js deleted file mode 100644 index 6df71ddb..00000000 --- a/src/ngMobile/directive/ngClick.js +++ /dev/null @@ -1,272 +0,0 @@ -'use strict'; - -/** - * @ngdoc directive - * @name ngMobile.directive:ngClick - * - * @description - * A more powerful replacement for the default ngClick designed to be used on touchscreen - * devices. Most mobile browsers wait about 300ms after a tap-and-release before sending - * the click event. This version handles them immediately, and then prevents the - * following click event from propagating. - * - * This directive can fall back to using an ordinary click event, and so works on desktop - * browsers as well as mobile. - * - * This directive also sets the CSS class `ng-click-active` while the element is being held - * down (by a mouse click or touch) so you can restyle the depressed element if you wish. - * - * @element ANY - * @param {expression} ngClick {@link guide/expression Expression} to evaluate - * upon tap. (Event object is available as `$event`) - * - * @example - <doc:example> - <doc:source> - <button ng-click="count = count + 1" ng-init="count=0"> - Increment - </button> - count: {{ count }} - </doc:source> - </doc:example> - */ - -ngMobile.config(['$provide', function($provide) { - $provide.decorator('ngClickDirective', ['$delegate', function($delegate) { - // drop the default ngClick directive - $delegate.shift(); - return $delegate; - }]); -}]); - -ngMobile.directive('ngClick', ['$parse', '$timeout', '$rootElement', - function($parse, $timeout, $rootElement) { - var TAP_DURATION = 750; // Shorter than 750ms is a tap, longer is a taphold or drag. - var MOVE_TOLERANCE = 12; // 12px seems to work in most mobile browsers. - var PREVENT_DURATION = 2500; // 2.5 seconds maximum from preventGhostClick call to click - var CLICKBUSTER_THRESHOLD = 25; // 25 pixels in any dimension is the limit for busting clicks. - - var ACTIVE_CLASS_NAME = 'ng-click-active'; - var lastPreventedTime; - var touchCoordinates; - - - // TAP EVENTS AND GHOST CLICKS - // - // Why tap events? - // Mobile browsers detect a tap, then wait a moment (usually ~300ms) to see if you're - // double-tapping, and then fire a click event. - // - // This delay sucks and makes mobile apps feel unresponsive. - // So we detect touchstart, touchmove, touchcancel and touchend ourselves and determine when - // the user has tapped on something. - // - // What happens when the browser then generates a click event? - // The browser, of course, also detects the tap and fires a click after a delay. This results in - // tapping/clicking twice. So we do "clickbusting" to prevent it. - // - // How does it work? - // We attach global touchstart and click handlers, that run during the capture (early) phase. - // So the sequence for a tap is: - // - global touchstart: Sets an "allowable region" at the point touched. - // - element's touchstart: Starts a touch - // (- touchmove or touchcancel ends the touch, no click follows) - // - element's touchend: Determines if the tap is valid (didn't move too far away, didn't hold - // too long) and fires the user's tap handler. The touchend also calls preventGhostClick(). - // - preventGhostClick() removes the allowable region the global touchstart created. - // - The browser generates a click event. - // - The global click handler catches the click, and checks whether it was in an allowable region. - // - If preventGhostClick was called, the region will have been removed, the click is busted. - // - If the region is still there, the click proceeds normally. Therefore clicks on links and - // other elements without ngTap on them work normally. - // - // This is an ugly, terrible hack! - // Yeah, tell me about it. The alternatives are using the slow click events, or making our users - // deal with the ghost clicks, so I consider this the least of evils. Fortunately Angular - // encapsulates this ugly logic away from the user. - // - // Why not just put click handlers on the element? - // We do that too, just to be sure. The problem is that the tap event might have caused the DOM - // to change, so that the click fires in the same position but something else is there now. So - // the handlers are global and care only about coordinates and not elements. - - // Checks if the coordinates are close enough to be within the region. - function hit(x1, y1, x2, y2) { - return Math.abs(x1 - x2) < CLICKBUSTER_THRESHOLD && Math.abs(y1 - y2) < CLICKBUSTER_THRESHOLD; - } - - // Checks a list of allowable regions against a click location. - // Returns true if the click should be allowed. - // Splices out the allowable region from the list after it has been used. - function checkAllowableRegions(touchCoordinates, x, y) { - for (var i = 0; i < touchCoordinates.length; i += 2) { - if (hit(touchCoordinates[i], touchCoordinates[i+1], x, y)) { - touchCoordinates.splice(i, i + 2); - return true; // allowable region - } - } - return false; // No allowable region; bust it. - } - - // Global click handler that prevents the click if it's in a bustable zone and preventGhostClick - // was called recently. - function onClick(event) { - if (Date.now() - lastPreventedTime > PREVENT_DURATION) { - return; // Too old. - } - - var touches = event.touches && event.touches.length ? event.touches : [event]; - var x = touches[0].clientX; - var y = touches[0].clientY; - // Work around desktop Webkit quirk where clicking a label will fire two clicks (on the label - // and on the input element). Depending on the exact browser, this second click we don't want - // to bust has either (0,0) or negative coordinates. - if (x < 1 && y < 1) { - return; // offscreen - } - - // Look for an allowable region containing this click. - // If we find one, that means it was created by touchstart and not removed by - // preventGhostClick, so we don't bust it. - if (checkAllowableRegions(touchCoordinates, x, y)) { - return; - } - - // If we didn't find an allowable region, bust the click. - event.stopPropagation(); - event.preventDefault(); - - // Blur focused form elements - event.target && event.target.blur(); - } - - - // Global touchstart handler that creates an allowable region for a click event. - // This allowable region can be removed by preventGhostClick if we want to bust it. - function onTouchStart(event) { - var touches = event.touches && event.touches.length ? event.touches : [event]; - var x = touches[0].clientX; - var y = touches[0].clientY; - touchCoordinates.push(x, y); - - $timeout(function() { - // Remove the allowable region. - for (var i = 0; i < touchCoordinates.length; i += 2) { - if (touchCoordinates[i] == x && touchCoordinates[i+1] == y) { - touchCoordinates.splice(i, i + 2); - return; - } - } - }, PREVENT_DURATION, false); - } - - // On the first call, attaches some event handlers. Then whenever it gets called, it creates a - // zone around the touchstart where clicks will get busted. - function preventGhostClick(x, y) { - if (!touchCoordinates) { - $rootElement[0].addEventListener('click', onClick, true); - $rootElement[0].addEventListener('touchstart', onTouchStart, true); - touchCoordinates = []; - } - - lastPreventedTime = Date.now(); - - checkAllowableRegions(touchCoordinates, x, y); - } - - // Actual linking function. - return function(scope, element, attr) { - var clickHandler = $parse(attr.ngClick), - tapping = false, - tapElement, // Used to blur the element after a tap. - startTime, // Used to check if the tap was held too long. - touchStartX, - touchStartY; - - function resetState() { - tapping = false; - element.removeClass(ACTIVE_CLASS_NAME); - } - - element.on('touchstart', function(event) { - tapping = true; - tapElement = event.target ? event.target : event.srcElement; // IE uses srcElement. - // Hack for Safari, which can target text nodes instead of containers. - if(tapElement.nodeType == 3) { - tapElement = tapElement.parentNode; - } - - element.addClass(ACTIVE_CLASS_NAME); - - startTime = Date.now(); - - var touches = event.touches && event.touches.length ? event.touches : [event]; - var e = touches[0].originalEvent || touches[0]; - touchStartX = e.clientX; - touchStartY = e.clientY; - }); - - element.on('touchmove', function(event) { - resetState(); - }); - - element.on('touchcancel', function(event) { - resetState(); - }); - - element.on('touchend', function(event) { - var diff = Date.now() - startTime; - - var touches = (event.changedTouches && event.changedTouches.length) ? event.changedTouches : - ((event.touches && event.touches.length) ? event.touches : [event]); - var e = touches[0].originalEvent || touches[0]; - var x = e.clientX; - var y = e.clientY; - var dist = Math.sqrt( Math.pow(x - touchStartX, 2) + Math.pow(y - touchStartY, 2) ); - - if (tapping && diff < TAP_DURATION && dist < MOVE_TOLERANCE) { - // Call preventGhostClick so the clickbuster will catch the corresponding click. - preventGhostClick(x, y); - - // Blur the focused element (the button, probably) before firing the callback. - // This doesn't work perfectly on Android Chrome, but seems to work elsewhere. - // I couldn't get anything to work reliably on Android Chrome. - if (tapElement) { - tapElement.blur(); - } - - if (!angular.isDefined(attr.disabled) || attr.disabled === false) { - element.triggerHandler('click', event); - } - } - - resetState(); - }); - - // Hack for iOS Safari's benefit. It goes searching for onclick handlers and is liable to click - // something else nearby. - element.onclick = function(event) { }; - - // Actual click handler. - // There are three different kinds of clicks, only two of which reach this point. - // - On desktop browsers without touch events, their clicks will always come here. - // - On mobile browsers, the simulated "fast" click will call this. - // - But the browser's follow-up slow click will be "busted" before it reaches this handler. - // Therefore it's safe to use this directive on both mobile and desktop. - element.on('click', function(event) { - scope.$apply(function() { - clickHandler(scope, {$event: event}); - }); - }); - - element.on('mousedown', function(event) { - element.addClass(ACTIVE_CLASS_NAME); - }); - - element.on('mousemove mouseup', function(event) { - element.removeClass(ACTIVE_CLASS_NAME); - }); - - }; -}]); - |
