From 72df1b6810a1e46e7767107e7c193474060a7163 Mon Sep 17 00:00:00 2001
From: Florian <info@codinginflow.com>
Date: Tue, 1 Sep 2020 10:43:48 -0700
Subject: [PATCH 1/8] End of part 2

---
 .../imagesearchapp/UnsplashPhoto.kt           | 30 +++++++++++
 app/src/main/res/drawable/gradient.xml        | 10 ++++
 app/src/main/res/layout/fragment_gallery.xml  | 51 +++++++++++++++++++
 .../main/res/layout/item_unsplash_photo.xml   | 33 ++++++++++++
 4 files changed, 124 insertions(+)
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/UnsplashPhoto.kt
 create mode 100644 app/src/main/res/drawable/gradient.xml
 create mode 100644 app/src/main/res/layout/fragment_gallery.xml
 create mode 100644 app/src/main/res/layout/item_unsplash_photo.xml

diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/UnsplashPhoto.kt b/app/src/main/java/com/codinginflow/imagesearchapp/UnsplashPhoto.kt
new file mode 100644
index 0000000..2062674
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/UnsplashPhoto.kt
@@ -0,0 +1,30 @@
+package com.codinginflow.imagesearchapp
+
+import android.os.Parcelable
+import kotlinx.android.parcel.Parcelize
+
+@Parcelize
+data class UnsplashPhoto(
+    val id: String,
+    val description: String?,
+    val urls: UnsplashPhotoUrls,
+    val user: UnsplashUser
+) : Parcelable {
+
+    @Parcelize
+    data class UnsplashPhotoUrls(
+        val raw: String,
+        val full: String,
+        val regular: String,
+        val small: String,
+        val thumb: String,
+    ) : Parcelable
+
+    @Parcelize
+    data class UnsplashUser(
+        val name: String,
+        val username: String
+    ) : Parcelable {
+        val attributionUrl get() = "https://unsplash.com/$username?utm_source=ImageSearchApp&utm_medium=referral"
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/res/drawable/gradient.xml b/app/src/main/res/drawable/gradient.xml
new file mode 100644
index 0000000..674f6c9
--- /dev/null
+++ b/app/src/main/res/drawable/gradient.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+
+    <gradient
+        android:startColor="#00FFFFFF"
+        android:endColor="#000"
+        android:angle="270" />
+
+</shape>
\ No newline at end of file
diff --git a/app/src/main/res/layout/fragment_gallery.xml b/app/src/main/res/layout/fragment_gallery.xml
new file mode 100644
index 0000000..78e1ce0
--- /dev/null
+++ b/app/src/main/res/layout/fragment_gallery.xml
@@ -0,0 +1,51 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/recycler_view"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+        tools:listitem="@layout/item_unsplash_photo" />
+
+    <ProgressBar
+        android:id="@+id/progress_bar"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_centerInParent="true"
+        android:visibility="gone"
+        tools:visibility="visible" />
+
+    <TextView
+        android:id="@+id/text_view_error"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_above="@id/button_retry"
+        android:layout_centerHorizontal="true"
+        android:text="Results could not be loaded"
+        android:visibility="gone"
+        tools:visibility="visible" />
+
+    <Button
+        android:id="@+id/button_retry"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_centerInParent="true"
+        android:text="Retry"
+        android:visibility="gone"
+        tools:visibility="visible" />
+
+    <TextView
+        android:id="@+id/text_view_empty"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_centerInParent="true"
+        android:text="No results found for this query"
+        android:visibility="gone"
+        tools:visibility="visible" />
+
+</RelativeLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/item_unsplash_photo.xml b/app/src/main/res/layout/item_unsplash_photo.xml
new file mode 100644
index 0000000..676d5a9
--- /dev/null
+++ b/app/src/main/res/layout/item_unsplash_photo.xml
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="250dp">
+
+    <ImageView
+        android:id="@+id/image_view"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
+
+    <View
+        android:layout_width="match_parent"
+        android:layout_height="40dp"
+        android:layout_alignBottom="@id/image_view"
+        android:background="@drawable/gradient" />
+
+    <TextView
+        android:id="@+id/text_view_user_name"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_alignBottom="@id/image_view"
+        android:layout_margin="8dp"
+        android:drawablePadding="4dp"
+        android:ellipsize="end"
+        android:gravity="center_vertical"
+        android:maxLines="1"
+        android:textColor="#fff"
+        app:drawableStartCompat="@drawable/ic_user"
+        tools:text="username" />
+
+</RelativeLayout>
\ No newline at end of file

From f5a0707bece620166105f13fb58fa83016e6db22 Mon Sep 17 00:00:00 2001
From: Florian <info@codinginflow.com>
Date: Tue, 1 Sep 2020 02:29:24 -0700
Subject: [PATCH 2/8] End of part 3

---
 .../imagesearchapp/{ => data}/UnsplashPhoto.kt    |  2 +-
 .../imagesearchapp/ui/gallery/GalleryFragment.kt  |  7 +++++++
 app/src/main/res/layout/activity_main.xml         | 15 +++++++--------
 app/src/main/res/layout/fragment_gallery.xml      |  3 ++-
 app/src/main/res/navigation/nav_graph.xml         | 13 +++++++++++++
 5 files changed, 30 insertions(+), 10 deletions(-)
 rename app/src/main/java/com/codinginflow/imagesearchapp/{ => data}/UnsplashPhoto.kt (93%)
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
 create mode 100644 app/src/main/res/navigation/nav_graph.xml

diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/UnsplashPhoto.kt b/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashPhoto.kt
similarity index 93%
rename from app/src/main/java/com/codinginflow/imagesearchapp/UnsplashPhoto.kt
rename to app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashPhoto.kt
index 2062674..a8bc5c9 100644
--- a/app/src/main/java/com/codinginflow/imagesearchapp/UnsplashPhoto.kt
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashPhoto.kt
@@ -1,4 +1,4 @@
-package com.codinginflow.imagesearchapp
+package com.codinginflow.imagesearchapp.data
 
 import android.os.Parcelable
 import kotlinx.android.parcel.Parcelize
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
new file mode 100644
index 0000000..70b7800
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
@@ -0,0 +1,7 @@
+package com.codinginflow.imagesearchapp.ui.gallery
+
+import androidx.fragment.app.Fragment
+import com.codinginflow.imagesearchapp.R
+
+class GalleryFragment : Fragment(R.layout.fragment_gallery) {
+}
\ No newline at end of file
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index 4fc2444..c928bb7 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -6,13 +6,12 @@
     android:layout_height="match_parent"
     tools:context=".MainActivity">
 
-    <TextView
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:text="Hello World!"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintLeft_toLeftOf="parent"
-        app:layout_constraintRight_toRightOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+    <androidx.fragment.app.FragmentContainerView
+        android:id="@+id/nav_host_fragment_main"
+        android:name="androidx.navigation.fragment.NavHostFragment"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        app:defaultNavHost="true"
+        app:navGraph="@navigation/nav_graph" />
 
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/fragment_gallery.xml b/app/src/main/res/layout/fragment_gallery.xml
index 78e1ce0..34059e8 100644
--- a/app/src/main/res/layout/fragment_gallery.xml
+++ b/app/src/main/res/layout/fragment_gallery.xml
@@ -3,7 +3,8 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
-    android:layout_height="match_parent">
+    android:layout_height="match_parent"
+    tools:context=".ui.gallery.GalleryFragment">
 
     <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/recycler_view"
diff --git a/app/src/main/res/navigation/nav_graph.xml b/app/src/main/res/navigation/nav_graph.xml
new file mode 100644
index 0000000..345204e
--- /dev/null
+++ b/app/src/main/res/navigation/nav_graph.xml
@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<navigation xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/nav_graph"
+    app:startDestination="@id/galleryFragment">
+
+    <fragment
+        android:id="@+id/galleryFragment"
+        android:name="com.codinginflow.imagesearchapp.ui.gallery.GalleryFragment"
+        android:label="fragment_gallery"
+        tools:layout="@layout/fragment_gallery" />
+</navigation>
\ No newline at end of file

From dbdebcd325bb9464fc6aaa97d3fb4a576d927317 Mon Sep 17 00:00:00 2001
From: Florian <info@codinginflow.com>
Date: Tue, 1 Sep 2020 03:27:08 -0700
Subject: [PATCH 3/8] End of part 4

---
 .../imagesearchapp/api/UnsplashApi.kt         | 22 +++++++++++++++++++
 .../imagesearchapp/api/UnsplashResponse.kt    |  7 ++++++
 2 files changed, 29 insertions(+)
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/api/UnsplashApi.kt
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/api/UnsplashResponse.kt

diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/api/UnsplashApi.kt b/app/src/main/java/com/codinginflow/imagesearchapp/api/UnsplashApi.kt
new file mode 100644
index 0000000..94f8e7c
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/api/UnsplashApi.kt
@@ -0,0 +1,22 @@
+package com.codinginflow.imagesearchapp.api
+
+import com.codinginflow.imagesearchapp.BuildConfig
+import retrofit2.http.GET
+import retrofit2.http.Headers
+import retrofit2.http.Query
+
+interface UnsplashApi {
+
+    companion object {
+        const val BASE_URL = "https://api.unsplash.com/"
+        const val CLIENT_ID = BuildConfig.UNSPLASH_ACCESS_KEY
+    }
+
+    @Headers("Accept-Version: v1", "Authorization: Client-ID $CLIENT_ID")
+    @GET("search/photos")
+    suspend fun searchPhotos(
+        @Query("query") query: String,
+        @Query("page") page: Int,
+        @Query("per_page") perPage: Int
+    ): UnsplashResponse
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/api/UnsplashResponse.kt b/app/src/main/java/com/codinginflow/imagesearchapp/api/UnsplashResponse.kt
new file mode 100644
index 0000000..e8b36ed
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/api/UnsplashResponse.kt
@@ -0,0 +1,7 @@
+package com.codinginflow.imagesearchapp.api
+
+import com.codinginflow.imagesearchapp.data.UnsplashPhoto
+
+data class UnsplashResponse(
+    val results: List<UnsplashPhoto>
+)
\ No newline at end of file

From 9e675b4b389d2b8735ad3aa0c8749a602d902cf0 Mon Sep 17 00:00:00 2001
From: Florian <info@codinginflow.com>
Date: Tue, 1 Sep 2020 04:38:43 -0700
Subject: [PATCH 4/8] End of part 5

---
 app/src/main/AndroidManifest.xml              |  1 +
 .../imagesearchapp/ImageSearchApplication.kt  |  8 +++++
 .../imagesearchapp/MainActivity.kt            |  2 ++
 .../imagesearchapp/data/UnsplashRepository.kt |  9 ++++++
 .../imagesearchapp/di/AppModule.kt            | 29 +++++++++++++++++++
 .../ui/gallery/GalleryFragment.kt             |  2 ++
 .../ui/gallery/GalleryViewModel.kt            | 10 +++++++
 7 files changed, 61 insertions(+)
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/ImageSearchApplication.kt
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashRepository.kt
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/di/AppModule.kt
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryViewModel.kt

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index d4c4aa9..761dbac 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -3,6 +3,7 @@
     package="com.codinginflow.imagesearchapp">
 
     <application
+        android:name=".ImageSearchApplication"
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ImageSearchApplication.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ImageSearchApplication.kt
new file mode 100644
index 0000000..f6c8783
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ImageSearchApplication.kt
@@ -0,0 +1,8 @@
+package com.codinginflow.imagesearchapp
+
+import android.app.Application
+import dagger.hilt.android.HiltAndroidApp
+
+@HiltAndroidApp
+class ImageSearchApplication : Application() {
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/MainActivity.kt b/app/src/main/java/com/codinginflow/imagesearchapp/MainActivity.kt
index 96e5c1c..d4ab7bb 100644
--- a/app/src/main/java/com/codinginflow/imagesearchapp/MainActivity.kt
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/MainActivity.kt
@@ -2,7 +2,9 @@ package com.codinginflow.imagesearchapp
 
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import dagger.hilt.android.AndroidEntryPoint
 
+@AndroidEntryPoint
 class MainActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashRepository.kt b/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashRepository.kt
new file mode 100644
index 0000000..958520a
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashRepository.kt
@@ -0,0 +1,9 @@
+package com.codinginflow.imagesearchapp.data
+
+import com.codinginflow.imagesearchapp.api.UnsplashApi
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class UnsplashRepository @Inject constructor(private val unsplashApi: UnsplashApi) {
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/di/AppModule.kt b/app/src/main/java/com/codinginflow/imagesearchapp/di/AppModule.kt
new file mode 100644
index 0000000..2916e21
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/di/AppModule.kt
@@ -0,0 +1,29 @@
+package com.codinginflow.imagesearchapp.di
+
+import com.codinginflow.imagesearchapp.api.UnsplashApi
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.components.ApplicationComponent
+import retrofit2.Retrofit
+import retrofit2.converter.gson.GsonConverterFactory
+import javax.inject.Singleton
+
+@Module
+@InstallIn(ApplicationComponent::class)
+object AppModule {
+
+    @Provides
+    @Singleton
+    fun provideRetrofit(): Retrofit =
+        Retrofit.Builder()
+            .baseUrl(UnsplashApi.BASE_URL)
+            .addConverterFactory(GsonConverterFactory.create())
+            .build()
+
+    @Provides
+    @Singleton
+    fun provideUnsplashApi(retrofit: Retrofit): UnsplashApi =
+        retrofit.create(UnsplashApi::class.java)
+
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
index 70b7800..872e78d 100644
--- a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
@@ -2,6 +2,8 @@ package com.codinginflow.imagesearchapp.ui.gallery
 
 import androidx.fragment.app.Fragment
 import com.codinginflow.imagesearchapp.R
+import dagger.hilt.android.AndroidEntryPoint
 
+@AndroidEntryPoint
 class GalleryFragment : Fragment(R.layout.fragment_gallery) {
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryViewModel.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryViewModel.kt
new file mode 100644
index 0000000..b22fca0
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryViewModel.kt
@@ -0,0 +1,10 @@
+package com.codinginflow.imagesearchapp.ui.gallery
+
+import androidx.hilt.lifecycle.ViewModelInject
+import androidx.lifecycle.ViewModel
+import com.codinginflow.imagesearchapp.data.UnsplashRepository
+
+class GalleryViewModel @ViewModelInject constructor(
+    private val repository: UnsplashRepository
+) : ViewModel() {
+}
\ No newline at end of file

From e9c14bd00c5115ccbadfe3170f7eeeb52b41b1f5 Mon Sep 17 00:00:00 2001
From: Florian <info@codinginflow.com>
Date: Wed, 2 Sep 2020 05:40:46 -0700
Subject: [PATCH 5/8] End of part 6

---
 .../data/UnsplashPagingSource.kt              | 33 +++++++++++++++++++
 .../imagesearchapp/data/UnsplashRepository.kt | 13 ++++++++
 .../ui/gallery/GalleryFragment.kt             | 13 ++++++++
 .../ui/gallery/GalleryViewModel.kt            | 18 ++++++++++
 4 files changed, 77 insertions(+)
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashPagingSource.kt

diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashPagingSource.kt b/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashPagingSource.kt
new file mode 100644
index 0000000..7423171
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashPagingSource.kt
@@ -0,0 +1,33 @@
+package com.codinginflow.imagesearchapp.data
+
+import androidx.paging.PagingSource
+import com.codinginflow.imagesearchapp.api.UnsplashApi
+import retrofit2.HttpException
+import java.io.IOException
+
+private const val UNSPLASH_STARTING_PAGE_INDEX = 1
+
+class UnsplashPagingSource(
+    private val unsplashApi: UnsplashApi,
+    private val query: String
+) : PagingSource<Int, UnsplashPhoto>() {
+
+    override suspend fun load(params: LoadParams<Int>): LoadResult<Int, UnsplashPhoto> {
+        val position = params.key ?: UNSPLASH_STARTING_PAGE_INDEX
+
+        return try {
+        val response = unsplashApi.searchPhotos(query, position, params.loadSize)
+        val photos = response.results
+
+            LoadResult.Page(
+                data = photos,
+                prevKey = if (position == UNSPLASH_STARTING_PAGE_INDEX) null else position - 1,
+                nextKey = if (photos.isEmpty()) null else position + 1
+            )
+        } catch (exception: IOException) {
+            LoadResult.Error(exception)
+        } catch (exception: HttpException) {
+            LoadResult.Error(exception)
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashRepository.kt b/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashRepository.kt
index 958520a..20f92c7 100644
--- a/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashRepository.kt
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/data/UnsplashRepository.kt
@@ -1,9 +1,22 @@
 package com.codinginflow.imagesearchapp.data
 
+import androidx.paging.Pager
+import androidx.paging.PagingConfig
+import androidx.paging.liveData
 import com.codinginflow.imagesearchapp.api.UnsplashApi
 import javax.inject.Inject
 import javax.inject.Singleton
 
 @Singleton
 class UnsplashRepository @Inject constructor(private val unsplashApi: UnsplashApi) {
+
+    fun getSearchResults(query: String) =
+        Pager(
+            config = PagingConfig(
+                pageSize = 20,
+                maxSize = 100,
+                enablePlaceholders = false
+            ),
+            pagingSourceFactory = { UnsplashPagingSource(unsplashApi, query) }
+        ).liveData
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
index 872e78d..98d6ead 100644
--- a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
@@ -1,9 +1,22 @@
 package com.codinginflow.imagesearchapp.ui.gallery
 
+import android.os.Bundle
+import android.view.View
 import androidx.fragment.app.Fragment
+import androidx.fragment.app.viewModels
 import com.codinginflow.imagesearchapp.R
 import dagger.hilt.android.AndroidEntryPoint
 
 @AndroidEntryPoint
 class GalleryFragment : Fragment(R.layout.fragment_gallery) {
+
+    private val viewModel by viewModels<GalleryViewModel>()
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+
+        viewModel.photos.observe(viewLifecycleOwner) {
+
+        }
+    }
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryViewModel.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryViewModel.kt
index b22fca0..b00192d 100644
--- a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryViewModel.kt
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryViewModel.kt
@@ -1,10 +1,28 @@
 package com.codinginflow.imagesearchapp.ui.gallery
 
 import androidx.hilt.lifecycle.ViewModelInject
+import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.switchMap
+import androidx.lifecycle.viewModelScope
+import androidx.paging.cachedIn
 import com.codinginflow.imagesearchapp.data.UnsplashRepository
 
 class GalleryViewModel @ViewModelInject constructor(
     private val repository: UnsplashRepository
 ) : ViewModel() {
+
+    private val currentQuery = MutableLiveData(DEFAULT_QUERY)
+
+    val photos = currentQuery.switchMap { queryString ->
+        repository.getSearchResults(queryString).cachedIn(viewModelScope)
+    }
+
+    fun searchPhotos(query: String) {
+        currentQuery.value = query
+    }
+
+    companion object {
+        private const val DEFAULT_QUERY = "cats"
+    }
 }
\ No newline at end of file

From 247e931f7b72bf330faa756883cff19cf616a655 Mon Sep 17 00:00:00 2001
From: Florian <info@codinginflow.com>
Date: Thu, 3 Sep 2020 02:52:27 -0700
Subject: [PATCH 6/8] End of part 7

---
 app/src/main/AndroidManifest.xml              |  3 +
 .../ui/gallery/GalleryFragment.kt             | 20 ++++++-
 .../ui/gallery/UnsplashPhotoAdapter.kt        | 58 +++++++++++++++++++
 3 files changed, 80 insertions(+), 1 deletion(-)
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/UnsplashPhotoAdapter.kt

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 761dbac..2d9b96b 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -2,6 +2,9 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.codinginflow.imagesearchapp">
 
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+
     <application
         android:name=".ImageSearchApplication"
         android:allowBackup="true"
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
index 98d6ead..e8a77e1 100644
--- a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
@@ -5,6 +5,7 @@ import android.view.View
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
 import com.codinginflow.imagesearchapp.R
+import com.codinginflow.imagesearchapp.databinding.FragmentGalleryBinding
 import dagger.hilt.android.AndroidEntryPoint
 
 @AndroidEntryPoint
@@ -12,11 +13,28 @@ class GalleryFragment : Fragment(R.layout.fragment_gallery) {
 
     private val viewModel by viewModels<GalleryViewModel>()
 
+    private var _binding: FragmentGalleryBinding? = null
+    private val binding get() = _binding!!
+
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
-        viewModel.photos.observe(viewLifecycleOwner) {
+        _binding = FragmentGalleryBinding.bind(view)
+
+        val adapter = UnsplashPhotoAdapter()
+
+        binding.apply {
+            recyclerView.setHasFixedSize(true)
+            recyclerView.adapter = adapter
+        }
 
+        viewModel.photos.observe(viewLifecycleOwner) {
+            adapter.submitData(viewLifecycleOwner.lifecycle, it)
         }
     }
+
+    override fun onDestroyView() {
+        super.onDestroyView()
+        _binding = null
+    }
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/UnsplashPhotoAdapter.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/UnsplashPhotoAdapter.kt
new file mode 100644
index 0000000..0c410cf
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/UnsplashPhotoAdapter.kt
@@ -0,0 +1,58 @@
+package com.codinginflow.imagesearchapp.ui.gallery
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.paging.PagingDataAdapter
+import androidx.recyclerview.widget.DiffUtil
+import androidx.recyclerview.widget.RecyclerView
+import com.bumptech.glide.Glide
+import com.bumptech.glide.load.resource.drawable.DrawableTransitionOptions
+import com.codinginflow.imagesearchapp.R
+import com.codinginflow.imagesearchapp.data.UnsplashPhoto
+import com.codinginflow.imagesearchapp.databinding.ItemUnsplashPhotoBinding
+
+class UnsplashPhotoAdapter :
+    PagingDataAdapter<UnsplashPhoto, UnsplashPhotoAdapter.PhotoViewHolder>(PHOTO_COMPARATOR) {
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): PhotoViewHolder {
+        val binding =
+            ItemUnsplashPhotoBinding.inflate(LayoutInflater.from(parent.context), parent, false)
+
+        return PhotoViewHolder(binding)
+    }
+
+    override fun onBindViewHolder(holder: PhotoViewHolder, position: Int) {
+        val currentItem = getItem(position)
+
+        if (currentItem != null) {
+            holder.bind(currentItem)
+        }
+    }
+
+    class PhotoViewHolder(private val binding: ItemUnsplashPhotoBinding) :
+        RecyclerView.ViewHolder(binding.root) {
+
+        fun bind(photo: UnsplashPhoto) {
+            binding.apply {
+                Glide.with(itemView)
+                    .load(photo.urls.regular)
+                    .centerCrop()
+                    .transition(DrawableTransitionOptions.withCrossFade())
+                    .error(R.drawable.ic_error)
+                    .into(imageView)
+
+                textViewUserName.text = photo.user.username
+            }
+        }
+    }
+
+    companion object {
+        private val PHOTO_COMPARATOR = object : DiffUtil.ItemCallback<UnsplashPhoto>() {
+            override fun areItemsTheSame(oldItem: UnsplashPhoto, newItem: UnsplashPhoto) =
+                oldItem.id == newItem.id
+
+            override fun areContentsTheSame(oldItem: UnsplashPhoto, newItem: UnsplashPhoto) =
+                oldItem == newItem
+        }
+    }
+}
\ No newline at end of file

From d1519c56984b10fc583bf5508ae70137e4c62c82 Mon Sep 17 00:00:00 2001
From: Florian <info@codinginflow.com>
Date: Sat, 5 Sep 2020 08:23:38 -0700
Subject: [PATCH 7/8] End of part 8

---
 .../ui/gallery/GalleryFragment.kt             |  5 ++-
 .../gallery/UnsplashPhotoLoadStateAdapter.kt  | 45 +++++++++++++++++++
 .../unsplash_photo_load_state_footer.xml      | 26 +++++++++++
 3 files changed, 75 insertions(+), 1 deletion(-)
 create mode 100644 app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/UnsplashPhotoLoadStateAdapter.kt
 create mode 100644 app/src/main/res/layout/unsplash_photo_load_state_footer.xml

diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
index e8a77e1..ced1325 100644
--- a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
@@ -25,7 +25,10 @@ class GalleryFragment : Fragment(R.layout.fragment_gallery) {
 
         binding.apply {
             recyclerView.setHasFixedSize(true)
-            recyclerView.adapter = adapter
+            recyclerView.adapter = adapter.withLoadStateHeaderAndFooter(
+                header = UnsplashPhotoLoadStateAdapter { adapter.retry() },
+                footer = UnsplashPhotoLoadStateAdapter { adapter.retry() },
+            )
         }
 
         viewModel.photos.observe(viewLifecycleOwner) {
diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/UnsplashPhotoLoadStateAdapter.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/UnsplashPhotoLoadStateAdapter.kt
new file mode 100644
index 0000000..8f366a3
--- /dev/null
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/UnsplashPhotoLoadStateAdapter.kt
@@ -0,0 +1,45 @@
+package com.codinginflow.imagesearchapp.ui.gallery
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.core.view.isVisible
+import androidx.paging.LoadState
+import androidx.paging.LoadStateAdapter
+import androidx.recyclerview.widget.RecyclerView
+import com.codinginflow.imagesearchapp.databinding.UnsplashPhotoLoadStateFooterBinding
+
+class UnsplashPhotoLoadStateAdapter(private val retry: () -> Unit) :
+    LoadStateAdapter<UnsplashPhotoLoadStateAdapter.LoadStateViewHolder>() {
+
+    override fun onCreateViewHolder(parent: ViewGroup, loadState: LoadState): LoadStateViewHolder {
+        val binding = UnsplashPhotoLoadStateFooterBinding.inflate(
+            LayoutInflater.from(parent.context),
+            parent,
+            false
+        )
+
+        return LoadStateViewHolder(binding)
+    }
+
+    override fun onBindViewHolder(holder: LoadStateViewHolder, loadState: LoadState) {
+        holder.bind(loadState)
+    }
+
+    inner class LoadStateViewHolder(private val binding: UnsplashPhotoLoadStateFooterBinding) :
+        RecyclerView.ViewHolder(binding.root) {
+
+        init {
+            binding.buttonRetry.setOnClickListener {
+                retry.invoke()
+            }
+        }
+
+        fun bind(loadState: LoadState) {
+            binding.apply {
+                progressBar.isVisible = loadState is LoadState.Loading
+                buttonRetry.isVisible = loadState !is LoadState.Loading
+                textViewError.isVisible = loadState !is LoadState.Loading
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/res/layout/unsplash_photo_load_state_footer.xml b/app/src/main/res/layout/unsplash_photo_load_state_footer.xml
new file mode 100644
index 0000000..dd95e9a
--- /dev/null
+++ b/app/src/main/res/layout/unsplash_photo_load_state_footer.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:gravity="center_horizontal"
+    android:orientation="vertical"
+    android:padding="8dp">
+
+    <ProgressBar
+        android:id="@+id/progress_bar"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content" />
+
+    <TextView
+        android:id="@+id/text_view_error"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Results could not be loaded" />
+
+    <Button
+        android:id="@+id/button_retry"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="Retry" />
+
+</LinearLayout>
\ No newline at end of file

From b98037e60fcebade49ec3e5500d69a106b679df6 Mon Sep 17 00:00:00 2001
From: Florian <info@codinginflow.com>
Date: Sat, 5 Sep 2020 00:07:30 -0700
Subject: [PATCH 8/8] End of part 9

---
 .../ui/gallery/GalleryFragment.kt             | 30 +++++++++++++++++++
 app/src/main/res/menu/menu_gallery.xml        | 12 ++++++++
 2 files changed, 42 insertions(+)
 create mode 100644 app/src/main/res/menu/menu_gallery.xml

diff --git a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
index ced1325..9704d4a 100644
--- a/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
+++ b/app/src/main/java/com/codinginflow/imagesearchapp/ui/gallery/GalleryFragment.kt
@@ -1,7 +1,10 @@
 package com.codinginflow.imagesearchapp.ui.gallery
 
 import android.os.Bundle
+import android.view.Menu
+import android.view.MenuInflater
 import android.view.View
+import androidx.appcompat.widget.SearchView
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
 import com.codinginflow.imagesearchapp.R
@@ -34,6 +37,33 @@ class GalleryFragment : Fragment(R.layout.fragment_gallery) {
         viewModel.photos.observe(viewLifecycleOwner) {
             adapter.submitData(viewLifecycleOwner.lifecycle, it)
         }
+
+        setHasOptionsMenu(true)
+    }
+
+    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
+        super.onCreateOptionsMenu(menu, inflater)
+
+        inflater.inflate(R.menu.menu_gallery, menu)
+
+        val searchItem = menu.findItem(R.id.action_search)
+        val searchView = searchItem.actionView as SearchView
+
+        searchView.setOnQueryTextListener(object : SearchView.OnQueryTextListener {
+            override fun onQueryTextSubmit(query: String?): Boolean {
+
+                if (query != null) {
+                    binding.recyclerView.scrollToPosition(0)
+                    viewModel.searchPhotos(query)
+                    searchView.clearFocus()
+                }
+                return true
+            }
+
+            override fun onQueryTextChange(newText: String?): Boolean {
+                return true
+            }
+        })
     }
 
     override fun onDestroyView() {
diff --git a/app/src/main/res/menu/menu_gallery.xml b/app/src/main/res/menu/menu_gallery.xml
new file mode 100644
index 0000000..e05b437
--- /dev/null
+++ b/app/src/main/res/menu/menu_gallery.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<menu xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <item
+        android:id="@+id/action_search"
+        android:icon="@drawable/ic_search"
+        android:title="Search"
+        app:actionViewClass="androidx.appcompat.widget.SearchView"
+        app:showAsAction="ifRoom|collapseActionView" />
+
+</menu>
\ No newline at end of file