Android-RecyclerView | using RecyclerView and CardView with Android L new features | Android library

logcat 2020-11-05 22:49:22.581 1663-1663/? W/ContextImpl: Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:1025 com.android.server.location.OppoSuplController.sendSuplConfigUpdateBroadcast:293 com.android.server.location.OppoSuplController.updateSuplConfig:274 com.android.server.location.OppoSuplController.access$1300:47 com.android.server.location.OppoSuplController$2.handleMessage:619 2020-11-05 22:49:22.582 1663-1663/? D/OppoSuplController: mSuplHostName : supl.google.com, mSuplHostPort : 7275, mSuplMode : 3, mMsaEnabled : true, mMsbEnabled : true, mSpecHostEnabled : true, mHostSwitchEnabled : true, mTelephonyImsi : 40494 2020-11-05 22:49:22.620 2935-2935/? D/CdmaVolteServiceChecker: onReceive, action = android.intent.action.SERVICE_STATE 2020-11-05 22:49:22.620 2935-2935/? D/CdmaVolteServiceChecker: updateState, checking = false 2020-11-05 22:49:22.620 2935-2935/? D/CdmaVolteServiceChecker: shouldShowVolteAlert cdma mixed volte support, return false. 2020-11-05 22:49:22.844 1663-3532/? E/Process: get_ion_cache_memory: Unable to open /d/ion/heaps/system 2020-11-05 22:49:22.980 1663-4211/? E/Process: get_ion_cache_memory: Unable to open /d/ion/heaps/system 2020-11-05 22:49:25.681 22324-22457/? E/Parcel: Reading a NULL string not supported here. 2020-11-05 22:49:27.649 1173-1382/? E/storaged: getDiskStats failed with result NOT_SUPPORTED and size 0 2020-11-05 22:49:28.068 1663-1663/? D/BatteryService: send broadcast : oppo.intent.action.BATTERY_DATA_UPDATE 2020-11-05 22:49:28.069 1663-1663/? W/ContextImpl: Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:1025 com.android.server.BatteryService$8.run:803 android.os.Handler.handleCallback:873 android.os.Handler.dispatchMessage:99 android.os.Looper.loop:226 2020-11-05 22:49:29.396 10556-10598/? W/Settings: Setting airplane_mode_on has moved from android.provider.Settings.System to android.provider.Settings.Global, returning read-only value. 2020-11-05 22:49:29.520 1663-1663/? D/Intent: disableDeathOnFileUriExposure com.android.chrome 2020-11-05 22:49:29.568 19152-19332/? I/BtGatt.ScanManager: msg.what = 6 2020-11-05 22:49:29.591 818-818/? I//vendor/bin/hw/vendor.qti.hardware.servicetracker@1.0-service: size of service connections for service: com.android.chrome/org.chromium.components.background_task_scheduler.BackgroundTaskJobServiceafter removal is 0 2020-11-05 22:49:29.591 818-818/? I//vendor/bin/hw/vendor.qti.hardware.servicetracker@1.0-service: size of client connections for client: systemafter removal is 16 2020-11-05 22:49:29.593 22324-23131/? D/Intent: disableDeathOnFileUriExposure com.android.chrome 2020-11-05 22:49:29.611 22324-22324/? E/cr_BkgrdTaskJS: Tried finishing non-current BackgroundTask. 2020-11-05 22:49:29.683 14000-24041/? E/MCS2.0_CIPHER_ALGO: checkSign 1 2020-11-05 22:49:29.691 14000-24041/? D/MCS2.0_CIPHER_ALGO: riv native_AES_encrypt flag 0 2020-11-05 22:49:34.182 1663-2761/? W/Watchdog: !@WatchDog_3773 2020-11-05 22:49:29.705 14000-24041/? D/MCS2.0_CIPHER_ALGO: riv native_AES_encrypt flag 0 2020-11-05 22:49:34.577 1663-1663/? D/Intent: disableDeathOnFileUriExposure com.facebook.katana 2020-11-05 22:49:34.622 19152-19332/? I/BtGatt.ScanManager: msg.what = 6 2020-11-05 22:49:35.253 818-818/? I//vendor/bin/hw/vendor.qti.hardware.servicetracker@1.0-service: size of service connections for service: com.facebook.katana/com.facebook.analytics2.logger.LollipopUploadServiceafter removal is 0 2020-11-05 22:49:35.253 818-818/? I//vendor/bin/hw/vendor.qti.hardware.servicetracker@1.0-service: size of client connections for client: systemafter removal is 16 2020-11-05 22:49:38.656 1663-1673/? I/system_server: Background concurrent copying GC freed 90991(7MB) AllocSpace objects, 40(976KB) LOS objects, 17% free, 36MB/44MB, paused 563us total 168.097ms 2020-11-05 22:49:38.830 1663-1663/? D/BatteryService: send broadcast : oppo.intent.action.BATTERY_DATA_UPDATE 2020-11-05 22:49:38.831 1663-1663/? W/ContextImpl: Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:1025 com.android.server.BatteryService$8.run:803 android.os.Handler.handleCallback:873 android.os.Handler.dispatchMessage:99 android.os.Looper.loop:226 2020-11-05 22:49:39.072 1663-4881/? W/System.err: java.io.FileNotFoundException: /proc/blackCheckStatus (No such file or directory) 2020-11-05 22:49:39.073 1663-4881/? W/System.err: at java.io.FileInputStream.open0(Native Method) 2020-11-05 22:49:39.073 1663-4881/? W/System.err: at java.io.FileInputStream.open(FileInputStream.java:231) 2020-11-05 22:49:39.073 1663-4881/? W/System.err: at java.io.FileInputStream.(FileInputStream.java:165) 2020-11-05 22:49:39.073 1663-4881/? W/System.err: at android.os.FileUtils.readTextFile(FileUtils.java:514) 2020-11-05 22:49:39.073 1663-4881/? W/System.err: at com.android.server.BootReceiver$2.run(BootReceiver.java:232) 2020-11-05 22:49:39.074 1663-4882/? W/System.err: java.io.FileNotFoundException: /proc/brightCheckStatus (No such file or directory) 2020-11-05 22:49:39.075 1663-4882/? W/System.err: at java.io.FileInputStream.open0(Native Method) 2020-11-05 22:49:39.075 1663-4882/? W/System.err: at java.io.FileInputStream.open(FileInputStream.java:231) 2020-11-05 22:49:39.075 1663-4882/? W/System.err: at java.io.FileInputStream.(FileInputStream.java:165) 2020-11-05 22:49:39.075 1663-4882/? W/System.err: at android.os.FileUtils.readTextFile(FileUtils.java:514) 2020-11-05 22:49:39.075 1663-4882/? W/System.err: at com.android.server.BootReceiver$3.run(BootReceiver.java:259) 2020-11-05 22:49:40.739 818-818/? I//vendor/bin/hw/vendor.qti.hardware.servicetracker@1.0-service: size of client connections for client: com.android.chromeafter removal is 3 2020-11-05 22:49:41.368 5961-5965/? E/rutils: releaseProcess gCount = 1 2020-11-05 22:49:41.475 10556-10598/? W/Settings: Setting airplane_mode_on has moved from android.provider.Settings.System to android.provider.Settings.Global, returning read-only value. 2020-11-05 22:49:49.067 1663-1663/? D/BatteryService: send broadcast : oppo.intent.action.BATTERY_DATA_UPDATE 2020-11-05 22:49:49.068 1663-1663/? W/ContextImpl: Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:1025 com.android.server.BatteryService$8.run:803 android.os.Handler.handleCallback:873 android.os.Handler.dispatchMessage:99 android.os.Looper.loop:226 2020-11-05 22:49:53.552 10556-10598/? W/Settings: Setting airplane_mode_on has moved from android.provider.Settings.System to android.provider.Settings.Global, returning read-only value. 2020-11-05 22:49:55.710 22324-22457/? E/Parcel: Reading a NULL string not supported here. 2020-11-05 22:50:00.080 1663-1663/? D/BatteryService: send broadcast : oppo.intent.action.BATTERY_DATA_UPDATE 2020-11-05 22:50:00.081 1663-1663/? W/ContextImpl: Calling a method in the system process without a qualified user: android.app.ContextImpl.sendBroadcast:1025 com.android.server.BatteryService$8.run:803 android.os.Handler.handleCallback:873 android.os.Handler.dispatchMessage:99 android.os.Looper.loop:226 builderror

Executing tasks: [:app:assembleDebug] in project G:\SOFTWARES\Recyclerview

Task :app:preBuild UP-TO-DATE Task :app:preDebugBuild UP-TO-DATE Task :app:compileDebugAidl NO-SOURCE Task :app:generateDebugBuildConfig UP-TO-DATE Task :app:compileDebugRenderscript NO-SOURCE Task :app:javaPreCompileDebug UP-TO-DATE Task :app:generateDebugResValues UP-TO-DATE Task :app:generateDebugResources UP-TO-DATE Task :app:createDebugCompatibleScreenManifests UP-TO-DATE Task :app:extractDeepLinksDebug UP-TO-DATE Task :app:processDebugManifest UP-TO-DATE Task :app:mergeDebugShaders UP-TO-DATE Task :app:compileDebugShaders NO-SOURCE Task :app:generateDebugAssets UP-TO-DATE Task :app:mergeDebugAssets UP-TO-DATE Task :app:mergeDebugResources Task :app:processDebugResources

Task :app:compileDebugJavaWithJavac G:\SOFTWARES\Recyclerview\app\src\main\java\com\example\recyclerview\MainActivity.java:23: error: cannot find symbol recyclerView = (RecyclerView) findViewById(R.id.recyclerView); ^ symbol: variable recyclerView location: class id Note: G:\SOFTWARES\Recyclerview\app\src\main\java\com\example\recyclerview\ProductAdapter.java uses or overrides a deprecated API. Note: Recompile with -Xlint:deprecation for details. 1 error

Task :app:compileDebugJavaWithJavac FAILED

FAILURE: Build failed with an exception.

• What went wrong: Execution failed for task ':app:compileDebugJavaWithJavac'.

Compilation failed; see the compiler error output for details.

• Try: Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

• Get more help at https://help.gradle.org

BUILD FAILED in 1m 14s 11 actionable tasks: 3 executed, 8 up-to-date

Mainactivity.java package com.example.recyclerview;

I am trying to make dynamical list using RecyclerView and CardView using tutorial from this site and I am getting this error:

I have a bit of a dilemma. I'll try to explain it as simply as I can.

My app has a page where I show a feed of posts through a recycler view (represented by the blue rectangles):

This is simple enough, as I've created a PostAdapter class for the recycler view where I handle all the child view logic.

Now I have another requirement where I need a page that shows a post (blue rectangle) at the top of the recycler view, and then the replies to that post below it (represented by the red rectangles):

Please remember that the blue and red rectangles are simplifications. Each of these views has dozens of child views and hundreds of lines of code of logic each.

I've created another class, ReplyAdapter, for the recycler view on this page, which handles all the logic for the replies.

My problem now becomes: how can I also show the post (blue rectangle) at the top of the recycler view?

I know that I can modify ReplyAdapter to allow for multiple types (as explained here), but because these are already two separate classes, each with their own complex logic, that's not really a possibility for me.

So my question is: is there a way to keep the logic of the two adapters separate while still being able to use both under the same recycler view? If so, how? If no, what should I do?

First of all, I have looked at similar questions (for example, this one: Android RecyclerView ItemTouchHelper revert swipe and restore view holder). This already helped a great deal, until I - more or less, accidentally - noticed my current (and hopefully, final) issue with this screen of mine.

Let's start with the setup:
I have a fragment with a RecyclerView filled with some CardView items (it's a little fancier, but that's what is important right now). I also created an ItemTouchHelper with the implementation of SimpleCallback (nothing in onMove()) to make swiping the items (right) possible. For the record: I am using API 27 right now. So far, so good.

What I want to achieve:
I want to be able to swipe the items to be notified through the onSwiped() method of my SimpleCallback implementation. Also, I do NOT want the items to disappear, be removed, or otherwise taken out of my list of items in the RecyclerView. I just want to swipe them and have them return to their original position afterward (and yes, I know that it is sort of assumed that swiped items get removed). I am using the notifyItemChanged() method of my adapter in the onSwiped() method (also tried using notifyDataSetChanged()).

The problem:
Funnily enough, that works (mostly thanks to the aforementioned question) - until I hit that "app switch" button (don't know if there's actually one official name for it) and send the app to the background. Once I put it in the foreground again and start swiping, the items will not (visually) return. They are still on the list, and if I scroll or click the "app switch" button again, they will be displayed properly again (but won't return on swiping). Same if I navigate back one screen and come back to the list.
That makes me think something happens when I send the app to the background and recover it. Something different than navigating to that screen (in which case everything works as intended) - which I thought would more or less produce the same results. Any ideas what I might be overlooking here?

I am using Android 3.6.1 and working on source code from https://www.android-examples.com/android-recyclerview-listview-with-imageview-textview-json/ where I am trying to retrieves the images from the server.

I have stored the images to the server and inserted absolute path in MYSQL Database as below How to retrives Images from above root path?. and what is URL for retrives the images

Following this guide, I tried implementing RecycleView into Fragments. I got the error E/RecyclerView: No adapter attached; skipping layout The recycle view don't display anything

I tried
recyclerview No adapter attached; skipping layout
RecyclerView in Fragment : No adapter attached skipping layout
and many more.

My Code:

I am implementing Two-Way DataBinding with Android Architecture Components using LiveData and ViewModel, but when I build the project it gives

I am implementing pagination logic with RecyclerView by adding addOnScrollListener function.

The onScrolled method is called once when the RecyclerView adapter is loaded with dy value of 0. However when the list reaches its end when scrolled, the onScrolled method is not triggered while the onScrollStateChanged is triggered correctly.

Here is my Adapter:

Following some articles, I am trying to create an android app with the following:

• A recyclerview which fetches data from room database using live data.
• Data structure is a list of custom objects with an attribute for ordering the data.

Features in recyclerview:

• Drag and drop for reordering data
• Swipe to delete
• UNDO action for swipe to delete

Referred articles:

1. Google codelabs for room database and live data
2. AndroidHive article for recyclerview swipe to delete and undo to restore deleted item
3. Medium post by Paul Burke for drag/drop in recycler view
4. Medium post by Paul Burke for customizing dragged item in recycler view
5. SO Post to detect drop event in recycler view

My problem:
Data reordering is not updated in the room library.

Note:
I am using an attribute for data ordering

Please refer this GitHub repository if you need more details of the implementation.I have created a sample app for this question.
(Adding complete code in question seems too long, kindly refer my github repository for the code)

Please drop a comment if code of a particular file is required.I am not sure which code to post.

MainFragment.java (Code to reorder data, which is not working)