Added ViewPager indicator that shows chapter availability

app/build.gradle

@@ -161,7 +161,6 @@ dependencies {
     implementation "com.joanzapata.iconify:android-iconify-fontawesome:$iconifyVersion"
     implementation "com.joanzapata.iconify:android-iconify-material:$iconifyVersion"
     implementation "com.yqritc:recyclerview-flexibledivider:$recyclerviewFlexibledividerVersion"
-    implementation "com.githang:viewpagerindicator:2.5.1@aar"
     implementation "com.github.shts:TriangleLabelView:$triangleLabelViewVersion"
     implementation 'com.leinardi.android:speed-dial:3.0.0'
     implementation "com.github.AntennaPod:AntennaPod-AudioPlayer:$audioPlayerVersion"

app/src/main/java/de/danoeh/antennapod/activity/MediaplayerInfoActivity.java

@@ -28,8 +28,6 @@ import android.widget.ListView;
 import android.widget.TextView;
 import android.widget.Toast;
 
-import com.viewpagerindicator.CirclePageIndicator;
-
 import java.util.List;
 
 import de.danoeh.antennapod.R;
@@ -38,6 +36,7 @@ import de.danoeh.antennapod.core.asynctask.FeedRemover;
 import de.danoeh.antennapod.core.dialog.ConfirmationDialog;
 import de.danoeh.antennapod.core.event.FeedListUpdateEvent;
 import de.danoeh.antennapod.core.event.MessageEvent;
+import de.danoeh.antennapod.core.feed.Chapter;
 import de.danoeh.antennapod.core.feed.Feed;
 import de.danoeh.antennapod.core.feed.FeedMedia;
 import de.danoeh.antennapod.core.preferences.UserPreferences;
@@ -59,6 +58,7 @@ import de.danoeh.antennapod.fragment.PlaybackHistoryFragment;
 import de.danoeh.antennapod.fragment.QueueFragment;
 import de.danoeh.antennapod.fragment.SubscriptionFragment;
 import de.danoeh.antennapod.menuhandler.NavDrawerActivity;
+import de.danoeh.antennapod.view.PagerIndicatorView;
 import io.reactivex.Observable;
 import io.reactivex.android.schedulers.AndroidSchedulers;
 import io.reactivex.disposables.Disposable;
@@ -102,6 +102,7 @@ public abstract class MediaplayerInfoActivity extends MediaplayerActivity implem
     private int mPosition = -1;
 
     private ViewPager pager;
+    private PagerIndicatorView pageIndicator;
     private MediaplayerInfoPagerAdapter pagerAdapter;
 
     private Disposable disposable;
@@ -261,7 +262,7 @@ public abstract class MediaplayerInfoActivity extends MediaplayerActivity implem
         pager.setOffscreenPageLimit(3);
         pagerAdapter = new MediaplayerInfoPagerAdapter(getSupportFragmentManager());
         pager.setAdapter(pagerAdapter);
-        CirclePageIndicator pageIndicator = findViewById(R.id.page_indicator);
+        pageIndicator = findViewById(R.id.page_indicator);
         pageIndicator.setViewPager(pager);
         loadLastFragment();
         pager.onSaveInstanceState();
@@ -269,6 +270,16 @@ public abstract class MediaplayerInfoActivity extends MediaplayerActivity implem
         navList.post(this::supportStartPostponedEnterTransition);
     }
 
+    @Override
+    boolean loadMediaInfo() {
+        if (controller != null) {
+            List<Chapter> chapters = controller.getMedia().getChapters();
+            boolean hasChapters = chapters != null && !chapters.isEmpty();
+            pageIndicator.setDisabledPage(hasChapters ? -1 : 2);
+        }
+        return super.loadMediaInfo();
+    }
+
     @Override
     protected void onReloadNotification(int notificationCode) {
         if (notificationCode == PlaybackService.EXTRA_CODE_VIDEO) {

app/src/main/java/de/danoeh/antennapod/view/PagerIndicatorView.java

@@ -0,0 +1,105 @@
+package de.danoeh.antennapod.view;
+
+import android.content.Context;
+import android.content.res.TypedArray;
+import android.database.DataSetObserver;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.util.AttributeSet;
+import android.view.View;
+import androidx.annotation.Nullable;
+import androidx.vectordrawable.graphics.drawable.ArgbEvaluator;
+import androidx.viewpager.widget.ViewPager;
+
+public class PagerIndicatorView extends View {
+    private final Paint paint = new Paint();
+    private float position = 0;
+    private int numPages = 0;
+    private int disabledPage = -1;
+    private int circleColor = 0;
+    private int circleColorHighlight = -1;
+
+    public PagerIndicatorView(Context context) {
+        super(context);
+        setup();
+    }
+
+    public PagerIndicatorView(Context context, @Nullable AttributeSet attrs) {
+        super(context, attrs);
+        setup();
+    }
+
+    public PagerIndicatorView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        setup();
+    }
+
+    private void setup() {
+        paint.setAntiAlias(true);
+        paint.setStyle(Paint.Style.FILL);
+
+        int[] colorAttrs = new int[] { android.R.attr.textColorSecondary };
+        TypedArray a = getContext().obtainStyledAttributes(colorAttrs);
+        circleColorHighlight = a.getColor(0, 0xffffffff);
+        circleColor = (Integer) new ArgbEvaluator().evaluate(0.8f, 0x00ffffff, circleColorHighlight);
+        a.recycle();
+    }
+
+    public void setViewPager(ViewPager pager) {
+        numPages = pager.getAdapter().getCount();
+        pager.getAdapter().registerDataSetObserver(new DataSetObserver() {
+            @Override
+            public void onChanged() {
+                numPages = pager.getAdapter().getCount();
+                invalidate();
+            }
+        });
+        pager.addOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
+            @Override
+            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
+                PagerIndicatorView.this.position = position + positionOffset;
+                invalidate();
+            }
+        });
+    }
+
+    public void setDisabledPage(int disabledPage) {
+        this.disabledPage = disabledPage;
+        invalidate();
+    }
+
+    @Override
+    protected void onDraw(Canvas canvas) {
+        super.onDraw(canvas);
+
+        for (int i = 0; i < numPages; i++) {
+            if ((int) Math.floor(position) == i) {
+                // This is the current dot
+                drawCircle(canvas, i, (float) (1 - (position - Math.floor(position))));
+            } else if ((int) Math.ceil(position) == i) {
+                // This is the next dot
+                drawCircle(canvas, i, (float) (position - Math.floor(position)));
+            } else {
+                drawCircle(canvas, i, 0);
+            }
+        }
+    }
+
+    private void drawCircle(Canvas canvas, int position, float frac) {
+        float circleRadiusSmall = canvas.getHeight() * 0.26f;
+        float circleRadiusBig = canvas.getHeight() * 0.35f;
+        float circleRadiusDelta = (circleRadiusBig - circleRadiusSmall);
+        float start = 0.5f * (canvas.getWidth() - numPages * 1.5f * canvas.getHeight());
+        paint.setStrokeWidth(canvas.getHeight() * 0.3f);
+
+        if (position == disabledPage) {
+            paint.setStyle(Paint.Style.STROKE);
+        } else {
+            paint.setStyle(Paint.Style.FILL_AND_STROKE);
+        }
+
+        paint.setColor((Integer) new ArgbEvaluator().evaluate(frac, circleColor, circleColorHighlight));
+        canvas.drawCircle(start + (position * 1.5f + 0.75f) * canvas.getHeight(), 0.5f * canvas.getHeight(),
+                circleRadiusSmall + frac * circleRadiusDelta, paint);
+    }
+}

app/src/main/res/layout/mediaplayerinfo_activity.xml

@@ -26,16 +26,13 @@
             android:minHeight="?attr/actionBarSize"
             tools:background="@android:color/darker_gray"/>
 
-            <com.viewpagerindicator.CirclePageIndicator
+            <de.danoeh.antennapod.view.PagerIndicatorView
                 android:id="@+id/page_indicator"
-                android:layout_height="wrap_content"
+                android:layout_height="8dp"
-                android:layout_width="match_parent"
+                android:layout_width="wrap_content"
                 android:layout_marginTop="-12dp"
                 android:layout_marginBottom="4dp"
-                android:background="@android:color/transparent"
+                android:background="@android:color/transparent"/>
-                app:fillColor="?android:attr/textColorSecondary"
-                app:strokeColor="?android:attr/textColorSecondary"
-                app:radius="4dp" />
 
         </com.google.android.material.appbar.AppBarLayout>