feat: implement "Resume All" functionality for downloads

[bermount]

Adds a "Resume All" button to the downloads screen that allows users to simultaneously resume all incomplete downloads. This is managed by tracking incomplete download IDs in preferences and implementing a new service action that fills available download slots up to the maximum concurrence limit. The button is hidden when there is no incomplete download.
Works with #8161 .

[Bnyro]

I personally think that this button is a bit unintuitive, i.e. the logo is just a download button and not really self-explainable.

Instead, I think it would look better to put the button in the same line as the sort order button.

I know this conflicts with the playlist name, but I think it's still the better solution. E.g. this could look like the following (tested locally):

diff --git a/app/src/main/java/com/github/libretube/ui/fragments/DownloadsFragment.kt b/app/src/main/java/com/github/libretube/ui/fragments/DownloadsFragment.kt
index 47123b199..fc38bbc78 100644
--- a/app/src/main/java/com/github/libretube/ui/fragments/DownloadsFragment.kt
+++ b/app/src/main/java/com/github/libretube/ui/fragments/DownloadsFragment.kt
@@ -231,6 +231,7 @@ class DownloadsFragmentPage : DynamicLayoutManagerFragment(R.layout.fragment_dow
                 }
 
                 binding.playlistName.text = playlist.downloadPlaylist.title
+                binding.playlistName.isVisible = true
 
                 playlist.downloadVideos.map { it.videoId }
             }
diff --git a/app/src/main/res/layout/fragment_download_content.xml b/app/src/main/res/layout/fragment_download_content.xml
index 151e3b0cf..bcb36d962 100644
--- a/app/src/main/res/layout/fragment_download_content.xml
+++ b/app/src/main/res/layout/fragment_download_content.xml
@@ -12,44 +12,64 @@
         android:layout_height="match_parent"
         android:orientation="vertical">
 
-        <LinearLayout
+        <RelativeLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:orientation="horizontal">
+            android:paddingHorizontal="8dp">
 
-            <TextView
-                android:id="@+id/playlist_name"
-                android:layout_width="0dp"
-                android:layout_weight="1"
+            <com.google.android.material.button.MaterialButton
+                android:id="@+id/resume_all"
+                android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
-                android:maxLines="1"
-                android:textSize="18sp"
-                android:textStyle="bold"
-                android:ellipsize="end"
-                android:paddingHorizontal="8dp"
-                tools:text="Downloaded Playlist Name"/>
+                android:text="@string/resume_all"
+                android:contentDescription="@string/resume_all"
+                app:icon="@drawable/ic_play"
+                android:tooltipText="@string/resume_all"
+                android:visibility="gone"
+                tools:targetApi="o"
+                tools:visibility="visible" />
 
             <com.google.android.material.button.MaterialButton
                 android:id="@+id/sort_type"
                 style="?materialButtonTonalStyle"
                 android:layout_width="wrap_content"
                 android:layout_height="wrap_content"
-            android:layout_marginEnd="8dp"
-            android:ellipsize="end"
+                android:layout_marginEnd="8dp"
+                android:ellipsize="end"
                 android:maxLines="1"
                 android:paddingHorizontal="10dp"
+                android:layout_alignParentEnd="true"
                 android:text="@string/sort_by"
                 app:icon="@drawable/ic_sort"
+                android:gravity="end"
                 app:iconGravity="textEnd" />
 
-        </LinearLayout>
+        </RelativeLayout>
+
+        <TextView
+            android:id="@+id/playlist_name"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:maxLines="1"
+            android:textSize="18sp"
+            android:textStyle="bold"
+            android:ellipsize="end"
+            android:paddingHorizontal="8dp"
+            android:visibility="gone"
+            tools:visibility="visible"
+            tools:text="Downloaded Playlist Name"/>
 
         <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/downloads_recView"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
-            android:orientation="vertical"/>
+            android:orientation="vertical" />
+
+        <androidx.fragment.app.FragmentContainerView
+            android:id="@+id/fragment"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent" />
 
     </LinearLayout>
 
@@ -78,23 +98,6 @@
             android:textStyle="bold" />
     </LinearLayout>
 
-    <com.google.android.material.floatingactionbutton.FloatingActionButton
-        android:id="@+id/resume_all"
-        style="?attr/floatingActionButtonSmallSecondaryStyle"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:layout_gravity="end"
-        android:layout_marginEnd="16dp"
-        android:layout_marginBottom="8dp"
-        android:contentDescription="@string/resume"
-        android:src="@drawable/ic_download"
-        android:tooltipText="@string/resume"
-        android:visibility="gone"
-        app:layout_constraintBottom_toTopOf="@+id/delete_all"
-        app:layout_constraintEnd_toEndOf="parent"
-        tools:targetApi="o"
-        tools:visibility="visible" />
-
     <com.google.android.material.floatingactionbutton.FloatingActionButton
         android:id="@+id/delete_all"
         style="?attr/floatingActionButtonSmallSecondaryStyle"
@@ -127,9 +130,4 @@
         tools:targetApi="o"
         tools:visibility="visible" />
 
-    <androidx.fragment.app.FragmentContainerView
-        android:id="@+id/fragment"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent" />
-
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 0c6fb58cc..1f5ac9cce 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -543,6 +543,7 @@
     <string name="include_timestamp_in_filename">Include timestamp in filename</string>
     <string name="did_you_mean">Did you mean:</string>
     <string name="showing_results_for">Showing results for:</string>
+    <string name="resume_all">Resume all</string>
 
     <!-- Notification channel strings -->
     <string name="download_channel_name">Download Service</string>

[Bnyro]

Instead of storing the incomplete download IDs in the preferences, can't we just iterate over all download items in the database and compare their downloadSize to the actual file size?

Or otherwise we should store an isFinished attribute in the DownloadItem table, instead of putting that information into the preferences store.

[Bnyro]

Very good idea, thanks for the PR 👍