Merge pull request #2871 from atpamat/main-window-tabs

make main page tabs scrollable and hide when there is only a single tab

app/src/main/java/org/schabi/newpipe/fragments/MainFragment.java

@@ -30,6 +30,7 @@ import org.schabi.newpipe.settings.tabs.Tab;
 import org.schabi.newpipe.settings.tabs.TabsManager;
 import org.schabi.newpipe.util.NavigationHelper;
 import org.schabi.newpipe.util.ServiceHelper;
+import org.schabi.newpipe.views.ScrollableTabLayout;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -37,7 +38,7 @@ import java.util.List;
 public class MainFragment extends BaseFragment implements TabLayout.OnTabSelectedListener {
     private ViewPager viewPager;
     private SelectedTabsPagerAdapter pagerAdapter;
-    private TabLayout tabLayout;
+    private ScrollableTabLayout tabLayout;
 
     private List<Tab> tabsList = new ArrayList<>();
     private TabsManager tabsManager;

app/src/main/java/org/schabi/newpipe/views/ScrollableTabLayout.java

@@ -0,0 +1,128 @@
+package org.schabi.newpipe.views;
+
+import android.content.Context;
+import android.os.Build;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.view.View;
+
+import androidx.annotation.NonNull;
+
+import com.google.android.material.tabs.TabLayout;
+import com.google.android.material.tabs.TabLayout.Tab;
+
+/**
+ * A TabLayout that is scrollable when tabs exceed its width.
+ * Hides when there are less than 2 tabs.
+ */
+public class ScrollableTabLayout extends TabLayout {
+    private static final String TAG = ScrollableTabLayout.class.getSimpleName();
+
+    private int layoutWidth = 0;
+    private int prevVisibility = View.GONE;
+
+    public ScrollableTabLayout(Context context) {
+        super(context);
+    }
+
+    public ScrollableTabLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public ScrollableTabLayout(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        super.onLayout(changed, l, t, r, b);
+
+        remeasureTabs();
+    }
+
+    @Override
+    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
+        super.onSizeChanged(w, h, oldw, oldh);
+
+        layoutWidth = w;
+    }
+
+    @Override
+    public void addTab(@NonNull Tab tab, int position, boolean setSelected) {
+        super.addTab(tab, position, setSelected);
+
+        hasMultipleTabs();
+
+        // Adding a tab won't decrease total tabs' width so tabMode won't have to change to FIXED
+        if (getTabMode() != MODE_SCROLLABLE) {
+            remeasureTabs();
+        }
+    }
+
+    @Override
+    public void removeTabAt(int position) {
+        super.removeTabAt(position);
+
+        hasMultipleTabs();
+
+        // Removing a tab won't increase total tabs' width so tabMode won't have to change to SCROLLABLE
+        if (getTabMode() != MODE_FIXED) {
+            remeasureTabs();
+        }
+    }
+
+    @Override
+    protected void onVisibilityChanged(View changedView, int visibility) {
+        super.onVisibilityChanged(changedView, visibility);
+
+        // Recheck content width in case some tabs have been added or removed while ScrollableTabLayout was invisible
+        // We don't have to check if it was GONE because then requestLayout() will be called
+        if (changedView == this) {
+            if (prevVisibility == View.INVISIBLE) {
+                remeasureTabs();
+            }
+            prevVisibility = visibility;
+        }
+    }
+
+    private void setMode(int mode) {
+        if (mode == getTabMode()) return;
+
+        setTabMode(mode);
+    }
+
+    /**
+     * Make ScrollableTabLayout not visible if there are less than two tabs
+     */
+    private void hasMultipleTabs() {
+        if (getTabCount() > 1) {
+            setVisibility(View.VISIBLE);
+        } else {
+            setVisibility(View.GONE);
+        }
+    }
+
+    /**
+     * Calculate minimal width required by tabs and set tabMode accordingly
+     */
+    private void remeasureTabs() {
+        if (prevVisibility != View.VISIBLE) return;
+        if (layoutWidth == 0) return;
+
+        final int count = getTabCount();
+        int contentWidth = 0;
+        for (int i = 0; i < count; i++) {
+            View child = getTabAt(i).view;
+            if (child.getVisibility() == View.VISIBLE) {
+                // Use tab's minimum requested width should actual content be too small
+                contentWidth += Math.max(child.getMinimumWidth(), child.getMeasuredWidth());
+            }
+        }
+
+        if (contentWidth > layoutWidth) {
+            setMode(TabLayout.MODE_SCROLLABLE);
+        } else {
+            setMode(TabLayout.MODE_FIXED);
+        }
+    }
+}

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

@@ -6,12 +6,13 @@
     android:layout_height="match_parent">
 
 
-    <com.google.android.material.tabs.TabLayout
+    <org.schabi.newpipe.views.ScrollableTabLayout
         android:id="@+id/main_tab_layout"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:layout_alignParentTop="true"
         android:background="?attr/colorPrimary"
+        app:tabMinWidth="60dp"
         app:tabGravity="fill"/>
 
     <androidx.viewpager.widget.ViewPager