delimicno odradjeno stranicenje #36

9 files changed, 201 insertions, 39 deletions

diff --git a/Client/BrzoDoLokacije/app/build.gradle b/Client/BrzoDoLokacije/app/build.gradle
index db4ed1b..e1ad943 100644
--- a/Client/BrzoDoLokacije/app/build.gradle
+++ b/Client/BrzoDoLokacije/app/build.gradle
@@ -52,6 +52,9 @@ dependencies {
     implementation 'com.google.android.gms:play-services-location:21.0.1'
     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
     implementation 'androidx.recyclerview:recyclerview:1.2.1'
+    implementation "androidx.paging:paging-runtime:3.0.0-alpha03"
+    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.5.1"
+
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.3'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
diff --git a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Adapters/ShowPostsAdapter.kt b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Adapters/ShowPostsAdapter.kt
index bbcf9e4..a827dcb 100644
--- a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Adapters/ShowPostsAdapter.kt
+++ b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Adapters/ShowPostsAdapter.kt
@@ -8,6 +8,8 @@ import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.ViewGroup
 import android.widget.Toast
+import androidx.paging.PagingDataAdapter
+import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.RecyclerView
 import com.bumptech.glide.Glide
 import com.example.brzodolokacije.Activities.ActivitySinglePost
@@ -25,10 +27,23 @@ import retrofit2.Response
 
 
 class ShowPostsAdapter (val activity:Activity,val items : MutableList<PostPreview>)
-    : RecyclerView.Adapter<ShowPostsAdapter.ViewHolder>() {
+    : PagingDataAdapter<PostPreview, ShowPostsAdapter.ViewHolder>(REPO_COMPARATOR) {
     private lateinit var token: String
     private lateinit var imageApi: IBackendApi
 
+    companion object{
+        private val REPO_COMPARATOR=object:DiffUtil.ItemCallback<PostPreview>(){
+            override fun areContentsTheSame(oldItem: PostPreview, newItem: PostPreview): Boolean {
+                return oldItem._id==newItem._id
+            }
+
+            override fun areItemsTheSame(oldItem: PostPreview, newItem: PostPreview): Boolean {
+                return oldItem._id==newItem._id
+            }
+        }
+    }
+
+
     //constructer has one argument - list of objects that need to be displayed
     //it is bound to xml of single item
     private lateinit var binding: PostPreviewBinding
@@ -42,20 +57,18 @@ class ShowPostsAdapter (val activity:Activity,val items : MutableList<PostPrevie
 
     override fun onBindViewHolder(holder: ViewHolder, position: Int) {
         //sets components of particular item
-        holder.bind(items[position])
+        holder.bind(getItem(position)!!)
         holder.itemView.setOnClickListener {
             //Toast.makeText(activity,item._id,Toast.LENGTH_LONG).show()
-            val intent:Intent = Intent(activity,ActivitySinglePost::class.java)
-            var b=Bundle()
-            items[position].location.type=LocationType.ADA
-            b.putParcelable("selectedPost", items[position])
-            intent.putExtras(b)
-            activity.startActivity(intent)
+//            val intent:Intent = Intent(activity,ActivitySinglePost::class.java)
+//            var b=Bundle()
+//            items[position].location.type=LocationType.ADA
+//            b.putParcelable("selectedPost", items[position])
+//            intent.putExtras(b)
+//            activity.startActivity(intent)
         }
     }
 
-
-    override fun getItemCount() = items.size
     inner class ViewHolder(itemView: PostPreviewBinding) : RecyclerView.ViewHolder(itemView.root) {
         fun bind(item: PostPreview) {
             binding.apply {
diff --git a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Fragments/FragmentShowPosts.kt b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Fragments/FragmentShowPosts.kt
index 83f6429..84df389 100644
--- a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Fragments/FragmentShowPosts.kt
+++ b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Fragments/FragmentShowPosts.kt
@@ -10,6 +10,10 @@ import android.view.View
 import android.view.ViewGroup
 import android.widget.ImageButton
 import android.widget.Toast
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.lifecycleScope
+import androidx.paging.PagingDataAdapter
+import androidx.paging.cachedIn
 import androidx.recyclerview.widget.GridLayoutManager
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
@@ -23,8 +27,14 @@ import com.example.brzodolokacije.Services.RetrofitHelper
 import com.example.brzodolokacije.Services.SharedPreferencesHelper
 import com.example.brzodolokacije.databinding.FragmentHomeBinding
 import com.example.brzodolokacije.databinding.FragmentShowPostsBinding
+import com.example.brzodolokacije.paging.SearchPostsRepository
+import com.example.brzodolokacije.paging.SearchPostsViewModel
+import com.example.brzodolokacije.paging.SearchPostsViewModelFactory
 import kotlinx.android.synthetic.main.fragment_show_posts.*
 import kotlinx.android.synthetic.main.fragment_show_posts.view.*
+import kotlinx.coroutines.flow.collectLatest
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.launch
 import okhttp3.ResponseBody
 import retrofit2.Call
 import retrofit2.Response
@@ -35,13 +45,15 @@ class FragmentShowPosts : Fragment(), SwipeRefreshLayout.OnRefreshListener {
     private lateinit var binding: FragmentShowPostsBinding
     private var posts : MutableList<PostPreview> = mutableListOf()
     private var linearManagerVar: RecyclerView.LayoutManager? = null
-    private var adapterVar: RecyclerView.Adapter<ShowPostsAdapter.ViewHolder>? = null
+    private var adapterVar: ShowPostsAdapter? = null
     private var recyclerView: RecyclerView?=null
     private var gridManagerVar: RecyclerView.LayoutManager?=null
     private var swipeRefreshLayout:SwipeRefreshLayout?=null
+    private lateinit var searchPostsViewModel:SearchPostsViewModel
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
+        setUpViewModel()
         binding=FragmentShowPostsBinding.inflate(layoutInflater)
         //instantiate adapter and linearLayout
         adapterVar=ShowPostsAdapter(requireActivity(),posts)
@@ -49,6 +61,11 @@ class FragmentShowPosts : Fragment(), SwipeRefreshLayout.OnRefreshListener {
         gridManagerVar=GridLayoutManager(activity,2)
     }
 
+    private fun setUpViewModel() {
+        val factory=SearchPostsViewModelFactory(RetrofitHelper.getInstance(),requireActivity())
+        searchPostsViewModel=ViewModelProvider(this@FragmentShowPosts,factory).get(SearchPostsViewModel::class.java)
+    }
+
     fun setUpListeners(rootView: View?){
         rootView?.findViewById<ImageButton>(R.id.btnGridLayout)?.setOnClickListener() {
             if(recyclerView?.layoutManager!=gridManagerVar){
@@ -66,32 +83,38 @@ class FragmentShowPosts : Fragment(), SwipeRefreshLayout.OnRefreshListener {
     }
 
     fun requestToBack(){
-        val postApi= RetrofitHelper.getInstance()
-        val token=SharedPreferencesHelper.getValue("jwt", requireActivity())
-        val request=postApi.getPosts("Bearer "+token)
-        request.enqueue(object : retrofit2.Callback<MutableList<PostPreview>?> {
-            override fun onResponse(call: Call<MutableList<PostPreview>?>, response: Response<MutableList<PostPreview>?>) {
-                if(response.isSuccessful){
-                    posts=response.body()!!
-                    recyclerView?.adapter=ShowPostsAdapter(requireActivity(),posts)
-                    Toast.makeText(
-                        activity, "prosao zahtev", Toast.LENGTH_LONG
-                    ).show()
-                    swipeRefreshLayout?.isRefreshing=false
-                }else{
-                    if(response.errorBody()!=null)
-                        Toast.makeText(activity, response.errorBody()!!.string(), Toast.LENGTH_LONG).show();
-                }
-
-
+        lifecycleScope.launch{
+            searchPostsViewModel.fetchPosts().distinctUntilChanged().collectLatest {
+                adapterVar?.submitData(it)
+                swipeRefreshLayout?.isRefreshing=false
             }
-
-            override fun onFailure(call: Call<MutableList<PostPreview>?>, t: Throwable) {
-                Toast.makeText(
-                    activity, t.toString(), Toast.LENGTH_LONG
-                ).show();
-            }
-        })
+        }
+//        val postApi= RetrofitHelper.getInstance()
+//        val token=SharedPreferencesHelper.getValue("jwt", requireActivity())
+//        val request=postApi.getPosts("Bearer "+token)
+//        request.enqueue(object : retrofit2.Callback<MutableList<PostPreview>?> {
+//            override fun onResponse(call: Call<MutableList<PostPreview>?>, response: Response<MutableList<PostPreview>?>) {
+//                if(response.isSuccessful){
+//                    posts=response.body()!!
+//                    recyclerView?.adapter=ShowPostsAdapter(requireActivity(),posts)
+//                    Toast.makeText(
+//                        activity, "prosao zahtev", Toast.LENGTH_LONG
+//                    ).show()
+//                    swipeRefreshLayout?.isRefreshing=false
+//                }else{
+//                    if(response.errorBody()!=null)
+//                        Toast.makeText(activity, response.errorBody()!!.string(), Toast.LENGTH_LONG).show();
+//                }
+//
+//
+//            }
+//
+//            override fun onFailure(call: Call<MutableList<PostPreview>?>, t: Throwable) {
+//                Toast.makeText(
+//                    activity, t.toString(), Toast.LENGTH_LONG
+//                ).show();
+//            }
+//        })
     }
 
     override fun onCreateView(
@@ -115,14 +138,16 @@ class FragmentShowPosts : Fragment(), SwipeRefreshLayout.OnRefreshListener {
             R.color.purple_700
         )
         swipeRefreshLayout?.post(kotlinx.coroutines.Runnable {
-            swipeRefreshLayout?.isRefreshing=true
+            //swipeRefreshLayout?.isRefreshing=true
             requestToBack()
         })
         return rootView
     }
 
     override fun onRefresh() {
-        requestToBack()
+        //requestToBack()
+        adapterVar!!.notifyDataSetChanged()
+        Log.d("main",adapterVar!!.itemCount.toString())
     }
 
 }
\ No newline at end of file
diff --git a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Interfaces/IBackendApi.kt b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Interfaces/IBackendApi.kt
index 2f5cff1..6d09251 100644
--- a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Interfaces/IBackendApi.kt
+++ b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Interfaces/IBackendApi.kt
@@ -54,6 +54,13 @@ interface IBackendApi {
     @GET("/api/user/posts")
     fun getMyPosts(@Header("Authorization") authHeader:String):Call<MutableList<PostPreview>>
 
+    @GET("/api/post/locations/{id}/posts")
+    suspend fun getPagedPosts(@Header("Authorization") authHeader: String,
+                        @Path("id") locationId:String,
+                        @Query("page") page:Int,
+                        @Query("sorttype") sorttype:Int,
+                        @Query("filterdate") filterdate:Int
+                        ):PagedPosts
 //@POST("putanja")
     //fun add(@Body obj:Post,@Header("Authorization") authHeader:String):Call<Post>
 }
\ No newline at end of file
diff --git a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Models/Post.kt b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Models/Post.kt
index 3bbcc0c..f990133 100644
--- a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Models/Post.kt
+++ b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/Models/Post.kt
@@ -71,4 +71,12 @@ data class Rating(
 data class RatingReceive(
     var rating:Int,
     var postId:String
-)
\ No newline at end of file
+)
+
+data class PagedPosts(
+    var page:Int,
+    var index:Int,
+    var totalpages:Int,
+    var totalposts:Int,
+    var posts:MutableList<PostPreview>
+)
diff --git a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsPagingSource.kt b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsPagingSource.kt
new file mode 100644
index 0000000..2f69a7a
--- /dev/null
+++ b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsPagingSource.kt
@@ -0,0 +1,36 @@
+package com.example.brzodolokacije.paging
+
+import android.app.Activity
+import android.util.Log
+import androidx.paging.PagingSource
+import com.example.brzodolokacije.Interfaces.IBackendApi
+import com.example.brzodolokacije.Models.PagedPosts
+import com.example.brzodolokacije.Models.PostPreview
+import com.example.brzodolokacije.Services.SharedPreferencesHelper
+import retrofit2.HttpException
+import java.io.IOException
+
+class SearchPostsPagingSource(
+    val backend: IBackendApi,
+    val activity: Activity
+):PagingSource<Int,PostPreview>() {
+    override suspend fun load(params: LoadParams<Int>): LoadResult<Int, PostPreview> {
+        val page=params.key?:0
+        val token=SharedPreferencesHelper.getValue("jwt", activity)
+        return try{
+            val response=backend.getPagedPosts("Bearer "+token,"6375784fe84e2d53df32bf03",
+                page,1,1
+            )
+            Log.d("main",page.toString())
+            LoadResult.Page(
+                response.posts,prevKey=if(page==0) null else page-1,
+                nextKey=if(response.posts.isEmpty()) null else page+1
+            )
+        }catch(exception:IOException){
+            return LoadResult.Error(exception)
+        }catch(exception:HttpException){
+            return LoadResult.Error(exception)
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsRepository.kt b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsRepository.kt
new file mode 100644
index 0000000..ae3a684
--- /dev/null
+++ b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsRepository.kt
@@ -0,0 +1,30 @@
+package com.example.brzodolokacije.paging
+
+import android.app.Activity
+import androidx.paging.Pager
+import androidx.paging.PagingConfig
+import androidx.paging.PagingData
+import androidx.paging.cachedIn
+import com.example.brzodolokacije.Models.PostPreview
+import com.example.brzodolokacije.Services.RetrofitHelper
+import kotlinx.coroutines.flow.Flow
+
+class SearchPostsRepository(val activity: Activity) {
+    companion object{
+        const val DEFAULT_PAGE_SIZE=20
+        const val DEFAULT_PAGE_INDEX=1
+
+        fun getInstance(activity: Activity)=SearchPostsRepository(activity)
+    }
+
+    fun letSearchedPostsFlow(pagingConfig: PagingConfig=getDefaultPageConfig()): Flow<PagingData<PostPreview>> {
+        return Pager(
+            config=pagingConfig,
+            pagingSourceFactory = {SearchPostsPagingSource(RetrofitHelper.getInstance(),activity)}
+        ).flow
+    }
+
+    private fun getDefaultPageConfig(): PagingConfig {
+        return PagingConfig(pageSize= DEFAULT_PAGE_SIZE, enablePlaceholders = false)
+    }
+}
\ No newline at end of file
diff --git a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsViewModel.kt b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsViewModel.kt
new file mode 100644
index 0000000..d0bf3ef
--- /dev/null
+++ b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsViewModel.kt
@@ -0,0 +1,25 @@
+package com.example.brzodolokacije.paging
+
+import android.app.Activity
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import androidx.paging.Pager
+import androidx.paging.PagingConfig
+import androidx.paging.PagingData
+import androidx.paging.cachedIn
+import com.example.brzodolokacije.Interfaces.IBackendApi
+import com.example.brzodolokacije.Models.PostPreview
+import kotlinx.coroutines.flow.Flow
+
+class SearchPostsViewModel(
+    private val api:IBackendApi,
+    val activity:Activity
+): ViewModel() {
+    val posts =
+        Pager(config = PagingConfig(pageSize = 10), pagingSourceFactory = {
+            SearchPostsPagingSource(api,activity)
+        }).flow.cachedIn(viewModelScope)
+    fun fetchPosts(): Flow<PagingData<PostPreview>>{
+        return SearchPostsRepository.getInstance(activity).letSearchedPostsFlow().cachedIn(viewModelScope)
+    }
+}
\ No newline at end of file
diff --git a/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsViewModelFactory.kt b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsViewModelFactory.kt
new file mode 100644
index 0000000..cddea54
--- /dev/null
+++ b/Client/BrzoDoLokacije/app/src/main/java/com/example/brzodolokacije/paging/SearchPostsViewModelFactory.kt
@@ -0,0 +1,15 @@
+package com.example.brzodolokacije.paging
+
+import android.app.Activity
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import com.example.brzodolokacije.Interfaces.IBackendApi
+
+class SearchPostsViewModelFactory(
+    val api:IBackendApi,
+    val activity: Activity
+):ViewModelProvider.NewInstanceFactory() {
+    override fun <T : ViewModel> create(modelClass: Class<T>): T {
+        return SearchPostsViewModel(api,activity) as T
+    }
+}
\ No newline at end of file