1 files changed, 71 insertions, 0 deletions
diff --git a/org.fox.ttrss/src/main/java/org/fox/ttrss/util/DetailActivityScrollingViewBehavior.java b/org.fox.ttrss/src/main/java/org/fox/ttrss/util/DetailActivityScrollingViewBehavior.java
new file mode 100644
index 00000000..85e8ae4b
--- /dev/null
+++ b/org.fox.ttrss/src/main/java/org/fox/ttrss/util/DetailActivityScrollingViewBehavior.java
@@ -0,0 +1,71 @@
+package org.fox.ttrss.util;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.preference.PreferenceManager;
+import android.util.AttributeSet;
+import android.view.View;
+
+import com.google.android.material.appbar.AppBarLayout;
+import com.google.android.material.floatingactionbutton.FloatingActionButton;
+
+import java.util.List;
+
+import androidx.annotation.NonNull;
+import androidx.coordinatorlayout.widget.CoordinatorLayout;
+import androidx.core.view.ViewCompat;
+
+public class DetailActivityScrollingViewBehavior extends AppBarLayout.ScrollingViewBehavior {
+
+    private SharedPreferences m_prefs;
+
+    public DetailActivityScrollingViewBehavior(Context context, AttributeSet attrs) {
+        super(context, attrs);
+
+        m_prefs = PreferenceManager
+                .getDefaultSharedPreferences(context);
+    }
+
+    @Override
+    public boolean layoutDependsOn(CoordinatorLayout parent, View child, View dependency) {
+        return super.layoutDependsOn(parent, child, dependency) ||
+                dependency instanceof FloatingActionButton;
+    }
+
+    @Override
+    public boolean onStartNestedScroll(@NonNull CoordinatorLayout coordinatorLayout,
+                                       @NonNull View child, @NonNull View directTargetChild,
+                                       @NonNull View target, int axes, int type) {
+        // Ensure we react to vertical scrolling
+        return axes == ViewCompat.SCROLL_AXIS_VERTICAL ||
+                super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, axes, type);
+    }
+
+    @Override
+    public void onNestedPreScroll(@NonNull CoordinatorLayout coordinatorLayout,
+                                  @NonNull View child, @NonNull View target, int dx, int dy,
+                                  @NonNull int[] consumed, int type) {
+        super.onNestedPreScroll(coordinatorLayout, child, target, dx, dy, consumed, type);
+
+        if (m_prefs.getBoolean("enable_article_fab", true)) {
+            if (dy > 0) {
+                // User scrolled down -> hide the FAB
+                List<View> dependencies = coordinatorLayout.getDependencies(child);
+                for (View view : dependencies) {
+                    if (view instanceof FloatingActionButton) {
+                        ((FloatingActionButton) view).hide();
+                    }
+                }
+            } else if (dy < 0) {
+                // User scrolled up -> show the FAB
+                List<View> dependencies = coordinatorLayout.getDependencies(child);
+                for (View view : dependencies) {
+                    if (view instanceof FloatingActionButton) {
+                        ((FloatingActionButton) view).show();
+                    }
+                }
+            }
+        }
+
+    }
+}
+\ No newline at end of file