I've been searching for a little while to investigate whether or not our Gtk+ 3 application (Gtk#, actually, but bound to Gtk+ 3) will be easily convertible to receive touch events rather than mouse clicks. This is pure investigation at the moment since I don't actually have a touch screen yet (that's also the reason why I can't easily test my theories).
As far as I can tell, the Gnome 3 can indeed do this and the documentation that seems relevant is the gesture stuff, found here.
I've not been able to find any sample Gtk+ code so I'm hoping it's a simple matter of instantiating one of the gesture classes and simply setting it up to deliver events to the main event loop.
Is there anyone with experience with Gtk gestures that can guide me in a simple example? Let's say I have a DrawableArea and I want to receive a very simple, single-touch event that gives me an event with the point within the area that was touched.
Once I have that, I should be able to build on it to handle swipes, pinches and so on.
You cannot inject pointer events as touch events: they are fundamentally different, and they interact with the gesture recognition state machine that lives inside GTK.
GTK has the ability (for debugging purposes) to emulate touch events via pointer, though obviously it cannot emulate multi-touch events because a pointing device only has one event sequence. If you have a recent version of GTK 3.x, you can use the GTK_TEST_TOUCHSCREEN environment variable set to a non-zero value.
If you want to know how to use GtkGesture implementations in your own widgets, then I suggest you look at the GtkGesture API reference, and look at the various types of gestures available, like GtkGestureSwipe or GtkGestureZoom. You're supposed to add GtkGesture instances to your widget when constructing it, and then catch the signals on the specific gesture when they are recognised.
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Just wanted to ask if there is any advantage for either using mouse click event or touch tap events, when writing apps for mobiles or tablets (for the iphone especially)?
I know that both of them should work fine, but in term of performance, is anyone better? Are there any things I should be aware of when choosing either?
By the way am using actionscript3 to implement the app.
This is probably the best documentation on Adobe AIR touch support:
http://help.adobe.com/en_US/as3/dev/WSb2ba3b1aad8a27b0-6ffb37601221e58cc29-8000.html
Midway through that page it states:
Note: Listening for touch and gesture events can consume a significant amount of processing resources (equivalent to rendering several frames per second), depending on the computing device and operating system. It is often better to use mouse events when you do not actually need the extra functionality provided by touch or gestures.
The only benefit of touch, I would think, would be multi-touch. The TouchEvent has a touchPointID which allows you to track the movement of each touch point. If you don't care about multi-touch, it sounds like Mouse Events would be the way to go.
Excellent question! Tap events are "technically" slower as they monitor multiple input points. If your only concerned with a single touch input, the standard mouse event system is just fine. For touch events, there's a couple objects being created per listener to assist in handling the multitouch functionality (however this is close to a tiny fractional ms loss in performance).
i think that the touchEvent is better than mouseevent when implement the app on tablets!i try it many times!you can have a test
I'm developing an application for iPhone, and I want to detect different shapes as my fingers move on iPhone surface. Can anybody help me, how can I detect the different geometric shapes via finger movement or gesture in iPhone sdk.
You can do it, but it's not an easy task. iPhone SDK provides UIGestureRecognizer class, you may create a subclass that UIGestureRecognizer that recognizes a distinctive gesture or character (in your case).
But there is also another approaches. One of them described by Brit Gardner in his blog. Underlying this approach is the N-Dollar Recognizer based on JavaScript. This guy had done a nice job and now you can use MultistrokeGestureRecognizer-iOS library for detecting symbols and shapes. Of course, this library is not perfect and it use specific way (like JSON) to recognize touches, but it's better than nothing.
Thanks, hope this help someone.
There is a sample custom UIGestureRecognizer built inside the iOS SDK documentation which recognizes a checkmark gesture here, specifically in the section entitled "Creating Custom Gesture Recognizers" (couldn't find an easy way to directly link the section). Using this as a template, you should be able write a custom gesture recognizer to correctly recognize your gesture.
The part you will have to provide yourself is the code which defines for your device what exactly it means to make your particular shape of interest.
Incidentally, I'm also in the process of writing my own custom UIGestureRecognizer as an example of recognizing a continuous gesture as opposed to the checkmark's discrete gesture recognition as I would have appreciated an example of this previously.
It is available on Github.
Back in 2009 Daniele Margutti created MCGestureRecognizer project also based upon http://depts.washington.edu/aimgroup/proj/dollar/
If you can find this it will give you a big heads up but will likely need updating to ios5. It used to be available at http://www.malcom-mac.com but that site seems to be down.
Hey, I was wondering if there was an event or something that can check if my user is holding down a button? (for iphone, iOS)
The Event class is TouchEvent. You'll need to toggle the touch state in a variable if you want to keep the fact someone is pressing down after the fact (of the event).
You can use MouseEvent if you need/desire a single touch point. Though you still need the variable.
You need to set Multitouch.inputMode to MultitouchInputMode.TOUCH_POINT in order to turn on touch events on the iPhone. Unfortunately, you can only test touch/gesture events on the iPhone itself. (MouseEvent and TouchEvent are virtually identical in use: MOUSE_DOWN = TOUCH_BEGIN, MOUSE_MOVE = TOUCH_MOVE, TOUCH_END = MOUSE_UP. The main difference is that you can only have one "mouse" yet multiple touches.)
Personally, I use MouseEvent to test on the machine, with an if-then setting up TouchEvent listeners if Multitouch.supportsTouchEvents is true (which it only is on the iPhone/Android).
If the button is a Cocoa Touch UIButton, you can easily connect a number of its gesture events from Interface builder to code Xcode IBActions (where you write the appropriate methods).
How your project would connect to flash, I am not sure. Give us more details and perhaps someone can better help. ;)
UIView's that don't handle their events pass them up the chain. By default, this passes them to their parent View, and if not handled (ultimately) to their parent UIViewController.
UIScrollView breaks this (there's lots of questions on SO, variations on the theme of "why does my app stop working once I add a UIScrollView?)
UISV decides whether the event is for itself, and if not, it passes it DOWN (into its subviews); if they don't handle the event, UISV just throws it away. That's the bug.
In that case, it's supposed to throw them back up to its own parent view - and ultimately parent UIVC. AFAICT, this is why so many people get confused: it's not working as documented (NB: as views are documented; UISV simply is "undocumented" on this matter - it doesn't declare what it aims to do in this situation).
So ... is there an easy fix for this bug? Is there a category I could write that would fix UISV in general and avoid me having to create "fake" UIView subclasses who exist purely to capture events and hand them where they're supposed to go? (which makes for bug-prone code)
In particular, from Apple's docs:
If the time fires without a significant change in position, the scroll view sends tracking events to the touched subview of the content view. If the user then drags their finger far enough before the timer elapses, the scroll view cancels any tracking in the subview and performs the scrolling itself.
...if I could override that "if the timer fires" method, and implement it correctly, I believe I could fix all my UISV instances.
But:
- would apple consider this "using a private API" (their description of "private" is nonsensical in normal programming terms, and I can't understand what they do and don't mean by it)
- does anyone know what this method is, or a good way to go about finding it? (debugging the compiled ObjC classes to find the symbol names, perhaps?)
I've found a partial answer, that's correct, but not 100% useable :(.
iPhone OS 4.0 lets you remotely add listeners to a given view, via the UIGestureRecognizer class. That's great, and works neatly.
Only problem is ... it won't work on any 3.x iPhones and iPod Touches.
(but if you're targetting 4.0 and above, it's an easy way forwards)
EDIT:
On OS 3.x, I created a custom UIView subclass that has extra properties:
NSObject *objectToDelegateToOnTouch;
id touchSourceIdentifier;
Whenever a touch comes in, the view sends the touch message directly to the objectToDelegateToOnTouch, but with the extra parameter of the touchSourceIdentifier.
This way, whenever you get a touch, you know where it came from (you can use an object, or a string, or anything you want as the "identifier").
The iPhone platform has a number of common gesture idioms. For example, there are taps, pinches, and swipes, each with varying number of fingers. But when you're developing an app, it's up to you to implement these things based on low-level information about the number and locations of touches. It seems like this is a prime candidate for a library. You would register a delegate, set some parameters like multi-tap interval and swipe threshold, and get calls like swipeStarted/Ended, pinchStarted/Ended, multiTap, etc. Does such a library exist?
I've set up just such a project. It's not a library, but it is full of sample code for pinch/stretch, tap and hold, etc.
Blog:
http://6tringle.com/blog/2009/TouchSampleCode.html
Github:
http://github.com/kailoa/6tringle-touchsamplecode/tree/master
Here is one for detecting the circle gesture, with the source code provided. Might be useful for adapting it to detect other geatures.
http://iphonedevelopment.blogspot.com/2009/04/detecting-circle-gesture.html
UIGestureRecognizer. Don’t roll your own.
I forked Kailoa's very nice example and attempted to create a library.
http://github.com/bentford/GestureDetect
I intend to add a combination "pinch-zoom and drag" gesture like the one in the maps app. Once I get it working, I'll post on github.