I've noticed that animateOpen(), animateClose() and animateToggle() are doing the same function, meaning that any one of them can replace the others.
The only difference that I noticed was that the speed of the animation varies from one method to the other as follows:
animateOpen(), the animation while opening is faster than the animation while closing.
animateClose(), the animation while closing is faster than the animation while opening.
animateToggle(), both speeds are equal.
So, my question is:
Am I missing something? or do I just have to check isOpened() before using any of them?
I'm asking this question because my problem raised when I wrote animateClose() somewhere, thinking that if the sliding drawer is already closed then no action will be taken, but I found out that it behaves exactly the same as animateToggle().
Confirmed, on two different devices.
animateClose() called on a drawer that is already closed will sometimes animate the drawer to opened.
animateOpen() called on a drawer that is already opened will always (?) animate the drawer to closed.
The immediate functions (close and open) seem to work as you would expect.
Given this, I would suggest subclassing the SlidingDrawer and overriding the 5 methods that open or close the drawer. Using a few member variable booleans, you should be able to determine the real state of the drawer and call (or not call) the appropriate superclass method, updating your state accordingly.
(It might also be necessary to implement the OnDrawerXxxListeners to keep your state correct; my drawer is only opened and closed programmatically, not using the "handle", so I didn't test that.)
Edit to add: The nice thing about doing this is that you can add an isOpening() and isClosing() based on your subclass's state plus the existing isMoving() method.
animateOpen, animateclose and animateToggle public methods will make the slide open,close or toggle with animaiton respectively. The methods have to be compared with open, close which will open and close the slider without animation. The speed of animation should not change in default implementation.
Related
Library used: appcompat-v7:22.2.1,design:22.2.1
Theme used:
Devices/Android versions reproduced on: Nexus 6
Issue: Return activity quickly redraws/appears then fades in with desired behaviour, only with "Don't keep activities alive".
I am wondering if this is a bug or expected behaviour. I have a very simple setup. Activity A contains a toolbar wrapped in an AppbarLayout and CoorindinatorLayout. The toolbar contains a Cardview and a TextView. Upon click of the TextView, Activity A launches Activity B. I am using shared elements and passing them through as Option's via ActivityCompat.StartActivity(bundle, options);
My shared elements work perfectly, even after device rotation. After reading about how I can PostPoneEnterTransition and combo it up with PreDrawListeners I am able to successfully achieve the desired transition even after rotation. My actual activity contains a Viewpager / TabLayout and 2+ fragments but for simplicity sake, I've stripped it back in the video as well as to see if something else was causing this issue.
While dealing with rotation and postponing of the enter transition back to Activity A, I decided to open developer options and check "Don't keep activities alive". The video depicts the app running with that option enabled. If you look closely, you can see upon return to Activity A, it is completely drawn and hidden very quickly and then the fade in occurs as well as the shared element transition.
I've also excluded the navigation bar and status bar in the animations so that I don't see those flicker (redraw redundantly).
My questions are:
Is this a bug, or am I missing a step in order to prevent this.
Why would the app/transitions behave differently with "Don't keep activities alive" vs a plain old device rotation (destroy/recreate).
I've noticed by playing around with some google apps, this behaviour does not occur, or at least that I could find. Is there a way to concretely check if the activity I am returning too is "completely destroyed" so I can cancel the animation? Or do something different?
I can include specifics and code samples if required but my setup is very simple, and reflects a bunch of boilerplate examples from the Android documentation / Stack-overflow.
Sorry I meant to respond to this earlier. What I ended up doing was recreating the example in a completely fresh project following code samples and tutorials as best I could. First making it work with a single image view, and then of course adding my custom layout which was a floating search bar. Everything worked as expected. I went back and reviewed my actual project source (which was littered with different attempts and commented out code while trying to debug this issue) and cleaned it up. I can't say for sure, but I believe it came down to two possible issues:
"Unless you do something unusual..." - Most likely I "was" doing something unusual by the time I created this issue do to my debugging efforts and lack of full comprehension of the shared elements transition framework and lifecycle.
I think what was happening was the shared element transition was failing do to views not being mapped properly. I was excluding the statusBarBackground inside a transition defined in XML. My statusBarBackground was set to transparent so that I had the nice overlay effect for an expanded drawer layout. I found out that while trying to add the statusbarbackground as a shared element via code, the view was actually null resulting in a crash (NPE). As well as I had set a background color (instead of transparent) to my drawer layout. I can't say for sure, but a combination of these mistakes lead to the strange behaviour.
To conclude, I would say that this issue should be closed and everything is working as intended. It would be nice to get a little more insight on handling a transparent status bar as a shared element.
Is this a bug, or am I missing a step in order to prevent this?
No. Everything is working as intended.
Why would the app/transitions behave differently with "Don't keep activities alive" vs a plain old device rotation (destroy/recreate)?
It doesn't. When everything is setup proper and your timing and mapping of shared elements is correct, "Don't keep activities alive" is a concrete way to test your transitions against configuration changes.
I've noticed by playing around with some google apps, this behaviour does not occur, or at least that I could find. Is there a way to concretely check if the activity I am returning too is "completely destroyed" so I can cancel the animation? Or do something different?
This is because the Google dev's did it right :)
For anyone struggling with shared elements, here is a bit of advice.
Start small. Use a single view first and confirm you are getting the correct behaviour in all circumstances, even after rotation and config changes, then you can add complexity.
Use SharedElementCallback to debug your transitions. You can check which views are mapped, which view failed etc.
I've recently been looking into the navigation system that Android uses with as intention to port my iOS app that uses an UITabBarController containing multiple UINavigationControllers. To replace the tab bar (which is not available on Android) I settled on using the built in DrawerLayout.
From what I've read, navigation in Android is generally done by creating an Intent, providing it with extras and then just replacing the current activity. This automatically makes sure the back button works, and optionally the back button in the top left if enabled.
However, I am not sure how to implement this way of navigation with the navigation drawer. The tutorial tells me to create a DrawerLayout containing a FrameLayout and a ListLayout where the FrameLayout will contain the actual application and the ListLayout will contain the navigation. This would mean that when I use the method described above to "navigate", it would replace the activity and thus removing the drawer.
What would be the best way to implement what I want (basic navigation with back button support while maintaining a global drawer navigation menu)? The possible options I can come up with is always keeping the same activity and dynamically replacing the FrameLayout, but that would mean a lot of boilerplate to render and possibly a hack to support the back button (and there would be no animations :(). The other option would be to just render the drawer on every activity (via subclassing or something), but that would mean that if the user navigates a lot the back button "stack" would become quite large.
I have tried to explain what I need in as much detail as possible, but it is quite hard to explain the concept. Basically, I want something similar to the UINavigationControllers in the UITabBarController.
You can either have one Activity with one NavigationDrawer and present the user with different views by switching Fragments back and forth within that one Activity. You would use the FragmentManager to switch between different Fragments.
Or you can use multiple Activities that all have a NavigationDrawer.
Second option might sound more difficult but it really isn't. You create a base Activity that all your Activities inherit from and all let them have their own NavigationDrawer, no problem.
Sure there's something in between or something completely different, but that's the most straightforward approaches I can think of.
The tutorial you've probably used (the one with the planets) is imho a bit misleading because it assumes a very basic app structure. If you have only little different 'screens' that might work, for a very complex application it's not suitable (again, in my opinion).
I've always opted for the second option because handling the navigation / backstack is just easier with Activities / Intents.
There's loads of different flags that you can set to your Intent to influence their navigation behaviour.
Also see this and that documentation. These documents might have been written when the NavigationDrawer pattern was not all that common but they are still useful.
There is slidingPaneLayout, which I need to keep opened.
First I tried to don use panelsidelistener, but it didn't work
Then I tried to set spl.openPane() that is also failed because it opened for some percents and opened again.
So I need to know how to keep it opened and deny slide it via touch?
Similar Posts Found But I Didn't Solve my problem. Sliding menu used in Activity class.
I have several widgets in a view, each needing its own ActionMode. I see that the ActionMode does not dismiss automatically when the user taps outside the action bar. Thus, it is easily possible for the user to start an ActionMode for one control, then tap (longclick in my case) another control and stack a second ActionBar on top of the first. This causes programming logic havoc.
I can keep track of the current ActionMode with an activity-level member variable and dismiss the current one if a new one is needed. Howewver, this is making my code messy to read and maintain. And further, I'd prefer to dismiss it immediately when the user taps anything outside the action bar.
Any suggestions on a good way to handle this?
I was looking for a solution of this problem some time ago and as I know you couldn't track it without saving current action-mode state in a global variable. However I don't think that one variable with proper name would make your code messy.
Sorry, I know that this topic has been covered a bit. I've read the related posts and am still a bit confused. I am working on an app that while the prototype will have 3 main screens, it will eventually have dozens. Each screen will present either dynmically changing status or take user input. To visualize, it is required to be laid out similar to how MS Word or a typical PC is. It has a status bar at the top and a navigation bar at the bottom that is common to all screens (slight tweaks for some screens, like different icons) in the middle is what I would call a view pane that needs to be updated with a applicable layout.
The status, nav bar, and each screen are defined in their own layout xml file. For my first swag at it I just used a ViewFlipper and loaded the 3 screen layouts into it. However that means that currently I have one main Activity which will not be maintainable as I continue to add screens.
It feels right to me that each screen layout should have an associated Activity class that understands how to control that screen. I need to figure out how to load that into the center pane dynamically. However I thought I read in another post that using multiple Activities can be a CPU and RAM drain.
Currently I tried making one of the screens it's own Activity and kick that off from the main Activity by creating an Intent and than calling startActivity. However that causes the new screen Activity to reside on top of the main Activity. The interesting thing is that then pressing the back button dismissed that activity and returns me to the main.
So far I haven't figured out how to setup having a different Activity control what happens in the center pane.
If I continue down the multiple Activity path, should my main Activity be inheriting from ActivityGroup?
Are using View classes more applicable in this case?
I know this has been a long post. I'd appreciate any advice.
Thanks!
CB
As you noticed, Android will implicitly track a stack of started activities in a task, and the 'back' button ends the top one, reactivating the next one down. I would advise you to think about which kinds of things the user might expect the back button to do, and make it so that activities are separated along those lines.
I haven't played with ActivityGroup so I can't advise you there. If you go with completely separate activities, you can have them all use the same "shell" content view with the common nav/status bar. Have a superclass or utility class handle populating and managing that from there. Then use a a LayoutInflater (you can call getLayoutInflater()) to fill in the middle with your Activity-specific view.
If you want one of the activities to have multiple screens, you might still end up with a ViewFlipper in the center slot. Again, you want to have an Activity transition wherever you want the user to be able to go "back"; that also means you may NOT want to have a change of activities in cases where screens are closely related or part of the same logical thing-being-done. (You can override the back button's behavior, but unless you have a good reason to, it's best to just arrange the app so that Android's basic setup helps your app's UI rather than working at cross purposes.)
If you want to use activities in the fashion you talked about, you might look into using a tab activity. It actually works in the way you want, you just need to hide the tab widget and put your navigation bar there instead. Or, you could go a little deeper and make you own similar tab-like ActivityGroup like Walter mentioned if you have more time.
You could use a view pager with fragments to accomplish the flip between the different views but still allow your activity to have full control over it. The activity can control the menus while the fragment controls your viewing area. This way your back button will properly dismiss the activity containing all pages related to the activity instead of walking down the stack.