I need to create a custom toggle-silder widget, like in the iphone, things like on-off items etc...
For the task i chose to inherit from LinearLayout, define it as Vertical and grab some xml attributes like the drawables that will be using for the buttons (one for on, one for off) and i just place two Views with the drawables as their backgrounds.
Now the issues i'm facing are:
i can catch onKeyDown and
onTouchEvent to discover swipe and
right-left-fire events so i'll
switch states for the button, but i
do wonder if there is a swipe event
read in the android system onSwipe
or should i try messing with the
GestureDetector ?
i want the sliding to be animated, i have no idea how to do that, any ideas where to start looking ?
ok if we take a look on this page:
http://developer.android.com/guide/topics/graphics/view-animation.html
we can see that we have simple way to create the animation, once onClick or onTouchStart is discovered (if not already processing), start the animation preloaded from the xml and disable touch on the View until animation ends(you cann add animation listener to animation object).
you should make sure fillAfter is true so the values will stick after animation ends.
the only issue with it is that it doesn't allow dragging like in iphone, possible solution would be to allow dragging up to certain delta and if that delta is passed ignore any onTouchMove events, disable touch and start the animation.
ofcourse deltas and animations should be updated according to the state of the button.
i might post code soon.
Related
I am making a game in which I have 5 buttons, looking like clouds, falling from the "sky".
That means that when my activity starts, 'clouds' cannot be seen, since the marginTop is set to -100dp.
From that position they start falling down untill they get lost on the bottom side of the screen.
The thing is, I need those buttons to be clickable, during the process of animation.
So far, I found some documentation about how I can make the buttons clickable AFTER the animation ends. But I don't need that. I need to be able to click on the buttons through the animation time itself.
NOTE: I need something that works with versions before 3.0.
Anybody has any link to documentation or some example or anything ?
After doing some research, I found out that there are two types of animations:
View Animation and Property Animation.
The view animation can only animate View objects. It also lack a variety of animations, since it can do only stuff as scale, rotate, move... It cannot change background color, for example.
Also, the disadvantage of the View Animation is that it only change the position of where the View object is DRAWN. Physically, it still stays in the same position.
That's why the button is un-clickable, after the View Animation is finished upon it.
Property Animation, in the other hand, can animate both View and non-View objects and it doesn't have constraints as the View Animation.
When objects are moved, for example, with the property animation, they are not just drawn on some other position on the screen, but they are actually MOVED there.
Now, Property Animation is a lot more complex to write than the View Animation, so if you don't really need all the advantages of the Property Animation, it is suggested to use View Animation.
Source:
Property vs View Animation
Tutorial and SupportLybrary up to API 1:
nineoldandroids
You can change the buttons to imageViews and then do
imageView.setOnClickListener(myListener)
then set myListener to do whatever you previously wanted to happen on the buttons onClick. Your activity will have to implement OnClickListener
Added bonus: you can make the images look like clouds :)
I want to implement the concept of "Slide to open" concept in my application. Basically, I am using an ImageView. If the user slide it to a specific direction (to the right for example), the next activity is started. I do not know how to implement this in Android, I have searched in lots of place but found nothing.
Any clues ?
What I came into :
No I do not think that the use of ViewPager or HorizontalScrollView is appropriate in this case.
I don't know if the concept of Drag And Drop helps (how to imply a drag in a specific direction ? How to let the ImageView return to its initial location if the drag ends midway ? ...)
Use frame layout and put a ImageView in it. Then add touchEvents to Imageview. update imagViews Layout parameters at ON_MOVE event.This is the basic idea of slide and drag stuff in android.Good luck.
you may use View.Animation for moving back the slider to start position again ON_UP event
you can move view only in x axis by only changing the views :
LayoutParams.leftMargin=event.getRawX();
(always set the gravity to NO_GRAVITY)
If you want to implement smth like "slide to unlock" you can implement drag and drop and forbid moving by Y axis for example. Also you can check image position and analys if this shift is enough to open\unlock, and if not - simple move this image back.
Doubtless this is caused by my decidedly unorthodox layout - I have buttons in a LinearLayout in an Activity which is placed by an ActivityGroup into a Gallery. The ActivityGroup is also the adapter implementation and the over-all effect is full-screen sliding, snapping panels.
This is working (a treat, actually) except that a touch event on the parent layout puts all the buttons into the pressed state (and any release removes the state). A touch on an individual button is only delivered to that button.
The buttons are not receiving any events, they're only changing state.
Have I done something obviously wrong? Is this a known bug and is there a work-around?
Any insights would be very much appreciated.
As obscure as this problem is its solution may be of use to someone else, so I'll answer my own question.
As mentioned, I'm (mis)using the Gallery to provide a slidey-panel à la iPhone. I do this by returning the top level window of an Activity when the Gallery asks its Adapter implementation for a view.
Typical use of a Gallery would result in small Views to which it's desirable for the press event to be applied - it's more like a button then it is a panel. Our use means that there are many buttons in a single view and we don't want the press event to ever be applied globally.
So the work-around was very easy. I extended Gallery and deliberately broke pointToPosition(int x, int y), returning INVALID_POSITION every time. The Gallery still does everything else expected of it but skips trying to apply the touch down event to any elements but itself (to prepare itself to scroll or fling).
I hope this is of value to someone.
I want to give my app a nice touch by allowing users to slide the page left or right instead of just using next/previous buttons (similar to the home screen).
What is the best way to do that? I assume I would have to override one of the Activity.on... methods and that I would also have to put my page's main View in a ViewGroup that allows me to shift pages left and right.
ViewFlipper is your friend!
Here you can see a nice video of the ViewFlipper in action and also a very good tutorial:
http://www.inter-fuser.com/2009/07/android-transistions-slide-in-and-slide.html
The solution is even easier these days with the release of Compatibility Package r3. You can download here: http://developer.android.com/sdk/compatibility-library.html
It includes
ViewPager: A ViewGroup that manages the layout for the child views, which the user can swipe between.
PagerAdapter: An adapter that populates the ViewPager with the views that represent each page.
and Fragment versions of those, if you are that way inclined.
The pager code is compatible back to API version 4 (1.6), and I just implemented a dynamically generated viewPager coming off a dynamically generated ListView in about 2 hours. I'm a novice, so this is definitely the preferred path.
There is an example app here: http://geekyouup.blogspot.com/2011/07/viewpager-example-from-paug.html
If one wants to flip between two activities perhaps one can apply this animated transition:
Intent intent = new Intent(FirstActivity.this, SecondActivity.class);
startActivity(intent);
finish();
//transition using XML view animations
overridePendingTransition(R.anim.slideinfromright, R.anim.slideouttoleft);
Use GestureDetector to detect if the touch event is a scroll.
If the first event to the first call to onScroll is ACTION_DOWN then you should see if it was a dominantly horizontal scroll. If so then your scroll is started and you should shift the absolute position of the view that fills the page.
For non deprecated absolute positioning, see my answer here Android: Alternative to AbsoluteLayout (I really do need absolute positioning)
You will want to be cautions of whether you return true to consume the touch events or not.
GestureDetector does not have a callback for scrolling having stopped. You will have to check if there was an ACTION_UP before you call GestureDetector.onTouchEvent and if there was an action up and you did have an unfinished scroll then you should set the absolute position to the destination location and use a TranslateAnimation to make it look nice moving from current to destination.
Edit:
GestureDetector did not work well at all if the child views also wanted to respond to touch events. I ended up creating a subclass of FrameLayout (one of the most basic layouts and the closest thing to a non intrusive parent view) and overriding dispatchTouchEvent. I just took all the events and did the detection myself.
cant we use Gallery view here?? with the adapter the whole page can be inflated inside gallery view adapter getView() and it will manage the left right scrolling perfectly.
The views are not cached in a ViewFlipper. Is there a way wherein we can get an image of the view and show it to user so that he sees the Ui as we see on Home scrren(when we swipe the previous view also moves along and when we lift our finger, only then the next view is shown completely.)
What I want to do is that when the user starts moving his finegr on screen, the view should also move along(create an image of view).
I am not getting to do this, as when we swipe the present view goes and next view comes, we do not get both visible when we r moving our finger on screen.
Please if anyone gets what I am trying to do, do help me.
Thanks,
Farha
It's tricky to get scroll and swipe tracking working on Android, while using ViewAnimator or its subclasses.
They allow you to set in and out animations and start them at a given moment, but they work with discrete, either-this-or-the-other-view animations. They are actually using FrameLayout and after in or out animation is executed, other views' visibility is set to View.GONE to hide them from showing up under/over your current View.
The Launcher and the Gallery application are actually doing the functionality you want, by using a different approach.
They track the user touch input (onTouchEvent()), on MotionEvent.ACTION_MOVE they perform animations manually and on MotionEvent.ACTION_UP snap to the appropriate view, just like in the iPhone.
Unfortunately, this approach is actually more complicated than it looks like.
With the manual handling, you have to ensure that you are taking care of everything related to the touch input. This includes a lot of flag-raising, value-checking, event-delegating, etc.
If you want to get better acquainted with this, take a look at these classes from Gallery3D or Launcher's source code.
One other way to get nice horizontal scrolling is to use HorizontalScrollView.
You have to figure out a way to recycle your views, like you would with a ListView and you have to add the snap-to-view logic, but if you have to take care of a small number of views it could be the easiest approach.
Hope that helps.