I am updating my scrolling game engine to output HTML5 code for the scrolling maps it generates, so that it can be used not only as a (somewhat-platform-specific) complete game creator, but also as a cross-platform HTML5 scrolling map editor. I got past the challenge of supporting the graphic tinting as described in my earlier question. And I have a nice sample running at http://sgdk2.enigmadream.com/ben/. However I have noticed that the mouse interaction for scrolling the map does not work on FireFox or on an iPod. It looks like iPod may use different events (ontouch etc) according to Native HTML5 Drag and Drop in Mobile Safari (iPad, iPod, iPhone)?. And that doesn't explain why FireFox wouldn't react. Isn't there a more universal way to support mouse or touch interaction? Do the touch events also work for mouse, or are they specific to touch? How would you recommend interacting with this scrolling map in the most cross-platform compatible way?
you need to correctly retrieve your srcElement
var srcEl = e.srcElement? e.srcElement : e.target;
try it
P.S.: see targets
Related
I am using simple HTML-5, and using Drag n Drop feature in React JS, without any library. I have implemented on web, it's working good but when i come to mobile it doesn't work. There are touch events to handle touch things for mobile but i am not achieve any solution. Please recommend some thing which works well.
There are few shim libs that emulate HTML5 drag and drop on mobile devices.
Example: DragDropTouch
They usually clone element that you try to drag on touchstart, copy all styles and put it to body, after that on touchmove they change position of this element and emulate drag events
The same I do when emulate native drag&drop inside dragee. It's work good on mobile devices as was developed to work on them and support multi touches
Since I´m working on a project where I need to be able to drag objects around my canvas but also to scroll the entire page by dragging the actual canvas 'background' behind my PIXI Sprites, i followed the findings of this guy here:
https://github.com/pixijs/pixi.js/issues/2483 :
By default, the Pixi canvas/display-area cannot be used to scroll the
webpage that contains it. Which is important on touch screens. (eg. If
you use the rest of the web-page to pinch-zoom into the Pixi canvas,
you can become trapped and unable to zoom back out (or pan away),
because there's no non-Pixi-canvas area of the page to "grab" with
your pinch gesture).
To enable this functionality, I use autoPreventDefault. But this comes
with some undesirable side-effects, like scroll/pinch-zoom actions
over the canvas registering "taps" or clicks in a way that doesn't
make sense. (ie. I'm attempting to zoom or scroll the outer page at
that point, not interact with the Pixi canvas)
To work around that, I modify and compile my own custom version of
Pixi where I can apply preventDefault in a more granular way...
To get page-scrolling functionality it seems I only need to
preventDefault in the InteractionManager.prototype.onTouchEnd
function. Whereas autoPreventDefault will also preventDefault on 3
other events. (onMouseDown, onTouchMove, onTouchStart).
Leaving autoPreventDefault = false and applying preventDefault only to
onTouchEnd, gives me the functionality I need. But it'd be nice to not
have to customize and rebuild Pixi in this way every release. (Sorry
if there's something else I'm missing here; I don't completely
understand the event system in Pixi, or what else to do about this
scroll-touch problem)
So i disabled e.preventDefault() on 'onTouchStart' and on 'onMouseMove' but left it as is on 'onTouchEnd'
This works perfect on IOS devices but not on Android, the only exception being a Samsung A7 using Adblock browser (fails on Chrome).
Would really appreciate some help on this.
TLDR:
Disabling PIXI´s e.preventDefault on onTouchStart and onMouseMove works on IOS devices and lets me scroll the page by draggin my canvas around but not on Android devices.
My solution for that was to use
renderer.plugins.interaction.autoPreventDefault = false
This should work on iOS and Android.
Docs for autoPreventDefault reads:
Should the manager automatically prevent default browser actions.
Using PIXI 4.5.6.
Take a look at the docs:
http://pixijs.download/dev/docs/PIXI.CanvasRenderer.html#plugins
http://pixijs.download/dev/docs/PIXI.interaction.InteractionManager.html
Using renderer.plugins.interaction.autoPreventDefault=true should do the trick.
So with scrolling events I can detect panning gestures in desktop browsers and modify content accordingly. But is there a way to detect also pinching (zooming) gestures? So that instead of browser zooming the whole site (or not doing anything) I could modify a DOM element accordingly.
There are laptops with such trackpads (like Magic Trackpad and Force Touch Trackpad). So gestures can be captured, but how can I use them in desktop web apps?
Imagine that you could pinch and zoom in our out in Google Map in desktop browser. And pan left and right with a hand gesture.
I would suggest using some specialized library like hammer.js. Have a look at this example of the hammer.js documentation, where they utilize pinch gesture recognition.
According to that example detecting the pinch gesture could be as simple as:
var myElement = document.getElementById('myElement'),
mc = new Hammer.Manager(myElement),
pinch = new Hammer.Pinch();
mc.add(pinch);
mc.on("pinch", function(ev) {
console.log('You sir did just pinch!');
});
However, if you only wanted to react to the changing viewport within your layout, you might be better off with using responsive design features like media queries.
Edit: It does not work that way. Thats because the desktop browsers do not yet support gesture events. However the second part of my answer remains true: you can use media queries based on the viewport dimensions and you could hook in on the resize events of the window as usual.
I am looking for the same thing - pinching on only a specific DOM element and not entire webpage (let's an embedded drawing app instead of the google maps example).
In the developer console from Chrome and Opera select Toggle Device Toolbar and chose a touch device. Pinching can be simulated by keeping the shift key + left mouse click pressed. Then check out the monitorEvents : https://developers.google.com/web/tools/chrome-devtools/debug/command-line/events?hl=en
Additionally, Hammer.js has a touch emulator library:
<script> TouchEmulator(); </script>
function log(ev) {
console.log(ev.touches);
}
document.body.addEventListener('touchmove', log, false);
Later edit. For the Google Maps specific example the viewport is set like this so that it uses its own zooming libraries and not the browser embedded .
<meta name="viewport" content="width=device-width, user-scalable=no, initial-scale=1">
I have started to use Hammer.js to implement drag functionality for mobile browsers. I have noticed that this functionality also works on desktop browsers (which is confirmed by this compatibility table https://github.com/EightMedia/hammer.js/wiki/Compatibility ).
Are there any drawbacks of using Hammer.js for desktop browsers as well?
As an example; let's say I want to implement a scrollbar (from scratch) where the "thumb" can be dragged. Instead of implementing this using onmousedown/up, onmousemove and set/release mousecapture I can simply use the dragstart, drag and dragend events of Hammer.js.
Hammer.js does a pretty good job on detecting whether it is running on a multitouch enabled system or not.
In most cases it also works pretty well when you have both, a mouse and a touch display. We are developing a desktop web-application based on hammer.js, which should work both, with mouse and multitouch interaction and it mostly works fine. However, it seems that this scenario is not as well tested as the use on mobile devices. See for example this open bug, when hammer.js triggers a tap event twice on Chrome (https://github.com/EightMedia/hammer.js/issues/302) which got closed in between, because no activity was detected.
Note also, that it is often needed to fine tune the behaviour of hammer.js, by fiddling with the user_select, user_drag and prevent_default parameters (see for example this question ). On Google Chrome we also had to enable the experimental touch-actions : none. I do not know, how much of this is specific to desktop systems though.
Summary
Hammer.js is written with desktop systems in mind and does quite a good job in providing sensible behaviour on both mouse and touch based systems. In detail it requires sometime fine tuning to make everything work as expected.
When I do a Google image search on my iPhone within the Safari mobile browser, it gives me this beautiful interface for flipping through the images. If I swipe left or right, it browses through the images. If I touch and move up or down, I get what appears to be the native Safari scroll function. Can anyone explain how Google does this? I'm only beginning to learn the Safari API for touch events. It seems like either you capture the touch event to attach handlers to swipe left or right or you let Safari handle the touch events natively, in which case you get the beautiful native Safari scrolling. Can anyone explain how Google captures left/right swipe but not scrolling?
There are touch-specific DOM Events. They've implemented a lot of JavaScript logic around them. Read the Safari Web Content Guideline: Handling Events Docs Also checkout out the official spec for Touch Events
A while back, I wrote a quick library to wrap some native-like gestures as HTML events JSGestureRecognizer. I don't really recommend using that library in production, but reading the source should give you a pretty good idea about how google went about listening to native Touch Events and doing complex user interfaces with them.