[Slider] Fixed behaviour when Slider is in a scrolling container

catalog/java/io/material/catalog/slider/SliderFragment.java

@@ -105,6 +105,13 @@ public Fragment createFragment() {
             return new SliderVerticalDemoFragment();
           }
         });
+    additionalDemos.add(
+        new Demo(R.string.cat_slider_demo_vertical_scroll_container_title) {
+          @Override
+          public Fragment createFragment() {
+            return new SliderVerticalScrollContainerDemoFragment();
+          }
+        });
     return additionalDemos;
   }
 

catalog/java/io/material/catalog/slider/SliderVerticalScrollContainerDemoFragment.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.material.catalog.slider;
+
+import android.os.Bundle;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.LinearLayout;
+
+import androidx.annotation.Nullable;
+
+import com.google.android.material.slider.Slider;
+import com.google.android.material.slider.SliderOrientation;
+
+import io.material.catalog.R;
+import io.material.catalog.feature.DemoFragment;
+
+/**
+ * A fragment that displays a list of vertical {@link Slider} inside a HorizontalScrollView to
+ * showcase how touch events are handled.
+ */
+public class SliderVerticalScrollContainerDemoFragment extends DemoFragment {
+
+  @Override
+  public View onCreateDemoView(
+      LayoutInflater layoutInflater, @Nullable ViewGroup viewGroup, @Nullable Bundle bundle) {
+    View view =
+        layoutInflater.inflate(
+            R.layout.cat_slider_demo_vertical_scroll, viewGroup, false /* attachToRoot */);
+    LinearLayout sliderContainer = view.findViewById(R.id.sliderContainer);
+    for (int i = 0; i < 50; i++) {
+      Slider slider = new Slider(layoutInflater.getContext());
+      slider.setValueTo(11f);
+      slider.setOrientation(SliderOrientation.VERTICAL);
+      sliderContainer.addView(
+          slider,
+          ViewGroup.LayoutParams.WRAP_CONTENT,
+          ViewGroup.LayoutParams.MATCH_PARENT);
+    }
+    return view;
+  }
+}

catalog/java/io/material/catalog/slider/res/layout/cat_slider_demo_vertical_scroll.xml

@@ -0,0 +1,31 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  Copyright 2019 The Android Open Source Project
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+  -->
+<HorizontalScrollView
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+  <LinearLayout
+    android:id="@+id/sliderContainer"
+      android:layout_width="match_parent"
+      android:layout_height="wrap_content"
+      android:paddingLeft="16dp"
+      android:paddingRight="16dp">
+
+
+  </LinearLayout>
+</HorizontalScrollView>

catalog/java/io/material/catalog/slider/res/values/strings.xml

@@ -23,6 +23,7 @@
   <string name="cat_slider_demo_corner_title" description="Title for the Slider with different corner sizes demo [CHAR LIMIT=NONE]">Slider custom corners demo</string>
   <string name="cat_slider_demo_icon_title" description="Title for the Slider with different track icons demo [CHAR LIMIT=NONE]">Slider track icons demo</string>
   <string name="cat_slider_demo_vertical_title" description="Title for the vertical Slider demo [CHAR LIMIT=NONE]">Slider vertical demo</string>
+  <string name="cat_slider_demo_vertical_scroll_container_title" description="Title for the vertical Slider inside scrolling container demo [CHAR LIMIT=NONE]">Vertical Slider in scrolling container demo</string>
 
   <string name="cat_slider_description" description="Body text describing the Slider widget within the design system [CHAR LIMIT=NONE]">
     Sliders let users select from a range of values by moving the slider thumb.

lib/java/com/google/android/material/slider/BaseSlider.java

@@ -338,6 +338,7 @@ abstract class BaseSlider<
   @Px private int trackIconSize;
   private int labelPadding;
   private float touchDownX;
+  private float touchDownY;
   private MotionEvent lastEvent;
   private LabelFormatter formatter;
   private boolean thumbIsPressed = false;
@@ -2863,18 +2864,25 @@ public boolean onTouchEvent(@NonNull MotionEvent event) {
       return false;
     }
 
-    float eventCoordinate = isVertical() ? event.getY() : event.getX();
-    touchPosition = (eventCoordinate - trackSidePadding) / trackWidth;
+    float eventCoordinateX = isVertical() ? event.getY() : event.getX();
+    float eventCoordinateY = isVertical() ? event.getX() : event.getY();
+    touchPosition = (eventCoordinateX - trackSidePadding) / trackWidth;
     touchPosition = max(0, touchPosition);
     touchPosition = min(1, touchPosition);
 
     switch (event.getActionMasked()) {
       case MotionEvent.ACTION_DOWN:
-        touchDownX = eventCoordinate;
+        touchDownX = eventCoordinateX;
+        touchDownY = eventCoordinateY;
 
         // If we're inside a vertical scrolling container,
         // we should start dragging in ACTION_MOVE
-        if (isPotentialVerticalScroll(event)) {
+        if (!isVertical() && isPotentialVerticalScroll(event)) {
+          break;
+        }
+        // If we're inside a horizontal scrolling container,
+        // we should start dragging in ACTION_MOVE
+        if (isVertical() && isPotentialHorizontalScroll(event)) {
           break;
         }
 
@@ -2897,8 +2905,13 @@ public boolean onTouchEvent(@NonNull MotionEvent event) {
       case MotionEvent.ACTION_MOVE:
         if (!thumbIsPressed) {
           // Check if we're trying to scroll vertically instead of dragging this Slider
-          if (isPotentialVerticalScroll(event)
-              && abs(eventCoordinate - touchDownX) < scaledTouchSlop) {
+          if (!isVertical() && isPotentialVerticalScroll(event)
+              && abs(eventCoordinateX - touchDownX) < scaledTouchSlop) {
+            return false;
+          }
+          // Check if we're trying to scroll horizontally instead of dragging this Slider
+          if (isVertical() && isPotentialHorizontalScroll(event)
+              && abs(eventCoordinateY - touchDownY) < scaledTouchSlop / 1.2) {
             return false;
           }
           getParent().requestDisallowInterceptTouchEvent(true);
@@ -3353,6 +3366,19 @@ private boolean isInVerticalScrollingContainer() {
     return false;
   }
 
+  private boolean isInHorizontalScrollingContainer() {
+    ViewParent p = getParent();
+    while (p instanceof ViewGroup) {
+      ViewGroup parent = (ViewGroup) p;
+      boolean canScrollHorizontally = parent.canScrollHorizontally(1) || parent.canScrollHorizontally(-1);
+      if (canScrollHorizontally && parent.shouldDelayChildPressedState()) {
+        return true;
+      }
+      p = p.getParent();
+    }
+    return false;
+  }
+
   private static boolean isMouseEvent(MotionEvent event) {
     return event.getToolType(0) == MotionEvent.TOOL_TYPE_MOUSE;
   }
@@ -3361,6 +3387,10 @@ private boolean isPotentialVerticalScroll(MotionEvent event) {
     return !isMouseEvent(event) && isInVerticalScrollingContainer();
   }
 
+  private boolean isPotentialHorizontalScroll(MotionEvent event) {
+    return !isMouseEvent(event) && isInHorizontalScrollingContainer();
+  }
+
   @SuppressWarnings("unchecked")
   private void dispatchOnChangedProgrammatically() {
     for (L listener : changeListeners) {