[Slider] Added option to show/hide tick marks in discrete mode

Resolves #1545

GIT_ORIGIN_REV_ID=6c5dc94df08ad7ec202722d5b546795f436de404
PiperOrigin-RevId: 324263710

catalog/java/io/material/catalog/slider/SliderDiscreteDemoFragment.java

@@ -48,6 +48,7 @@ public View onCreateDemoView(
     setUpSlider(view, R.id.switch_button_3, R.id.slider_3, null);
     setUpSlider(view, R.id.switch_button_4, R.id.slider_4, new BasicLabelFormatter());
     setUpSlider(view, R.id.switch_button_5, R.id.slider_5, null);
+    setUpSlider(view, R.id.switch_button_6, R.id.slider_6, null);
 
     return view;
   }

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

@@ -16,6 +16,7 @@
   -->
 <ScrollView
     xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
@@ -175,5 +176,36 @@
           android:valueTo="5.75"
           android:stepSize="0.25" />
     </LinearLayout>
+
+    <TextView
+      android:layout_width="wrap_content"
+      android:layout_height="wrap_content"
+      android:paddingTop="@dimen/cat_slider_title_top_padding"
+      android:text="@string/cat_slider_title_6"/>
+
+    <LinearLayout
+      android:layout_width="match_parent"
+      android:layout_height="wrap_content"
+      android:gravity="center_vertical">
+
+      <androidx.appcompat.widget.SwitchCompat
+        android:id="@+id/switch_button_6"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:theme="@style/ThemeOverlay.SecondaryPalette.Green" />
+
+      <com.google.android.material.slider.Slider
+        android:id="@+id/slider_6"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_weight="1"
+        android:layout_marginLeft="@dimen/cat_slider_left_margin"
+        android:layout_marginStart="@dimen/cat_slider_left_margin"
+        android:theme="@style/ThemeOverlay.PrimaryPalette.Green"
+        android:valueFrom="0"
+        android:valueTo="10"
+        android:stepSize="1"
+        app:tickVisible="false"/>
+    </LinearLayout>
   </LinearLayout>
 </ScrollView>

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

@@ -34,6 +34,7 @@
   <string name="cat_slider_title_3" description="The title for a demonstration slider">Negative numbers!</string>
   <string name="cat_slider_title_4" description="The title for a demonstration slider">With a label formatter</string>
   <string name="cat_slider_title_5" description="The title for a demonstration slider">I can have decimal numbers?</string>
+  <string name="cat_slider_title_6" description="The title for a demonstration slider">Without tick marks</string>
   <string name="cat_slider_start_touch_description" description="Indicates the slider is now being touched">Slider started being touched</string>
   <string name="cat_slider_stop_touch_description" description="Indicates the slider stopped being touched">Slider stopped being touched</string>
 

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

@@ -125,6 +125,8 @@
  *       discrete mode. This is a short hand for setting both the {@code tickColorActive} and {@code
  *       tickColorInactive} to the same thing. This takes precedence over {@code tickColorActive}
  *       and {@code tickColorInactive}.
+ *   <li>{@code tickVisible}: Whether to show the tick marks. Only used when the slider is in
+ *       discrete mode.
  *   <li>{@code trackColorActive}: The color of the active part of the track.
  *   <li>{@code trackColorInactive}: The color of the inactive part of the track.
  *   <li>{@code trackColor}: The color of the whole track. This is a short hand for setting both the
@@ -167,6 +169,7 @@
  * @attr ref com.google.android.material.R.styleable#Slider_tickColor
  * @attr ref com.google.android.material.R.styleable#Slider_tickColorActive
  * @attr ref com.google.android.material.R.styleable#Slider_tickColorInactive
+ * @attr ref com.google.android.material.R.styleable#Slider_tickVisible
  * @attr ref com.google.android.material.R.styleable#Slider_trackColor
  * @attr ref com.google.android.material.R.styleable#Slider_trackColorActive
  * @attr ref com.google.android.material.R.styleable#Slider_trackColorInactive
@@ -244,6 +247,7 @@ private interface TooltipDrawableFactory {
   private int focusedThumbIdx = -1;
   private float stepSize = 0.0f;
   private float[] ticksCoordinates;
+  private boolean tickVisible = true;
   private int trackWidth;
   private boolean forceDrawCompatHalo;
   private boolean isLongPress = false;
@@ -401,6 +405,7 @@ private void processAttributes(Context context, AttributeSet attrs, int defStyle
             ? haloColor
             : AppCompatResources.getColorStateList(context, R.color.material_slider_halo_color));
 
+    tickVisible = a.getBoolean(R.styleable.Slider_tickVisible, true);
     boolean hasTickColor = a.hasValue(R.styleable.Slider_tickColor);
     int tickColorInactiveRes =
         hasTickColor ? R.styleable.Slider_tickColor : R.styleable.Slider_tickColorInactive;
@@ -1119,6 +1124,29 @@ public void setTickInactiveTintList(@NonNull ColorStateList tickColor) {
     invalidate();
   }
 
+  /**
+   * Returns whether the tick marks are visible. Only used when the slider is in discrete mode.
+   *
+   * @see #setTickVisible(boolean)
+   * @attr ref com.google.android.material.R.styleable#Slider_tickVisible
+   */
+  public boolean isTickVisible() {
+    return tickVisible;
+  }
+
+  /**
+   * Sets whether the tick marks are visible. Only used when the slider is in discrete mode.
+   *
+   * @param tickVisible The visibility of tick marks.
+   * @attr ref com.google.android.material.R.styleable#Slider_tickVisible
+   */
+  public void setTickVisible(boolean tickVisible) {
+    if (this.tickVisible != tickVisible){
+      this.tickVisible = tickVisible;
+      postInvalidate();
+    }
+  }
+
   /**
    * Returns the color of the track if the active and inactive parts aren't different.
    *
@@ -1270,14 +1298,16 @@ protected void onSizeChanged(int w, int h, int oldw, int oldh) {
     trackWidth = Math.max(w - trackSidePadding * 2, 0);
 
     // Update the visible tick coordinates.
-    if (stepSize > 0.0f) {
-      calculateTicksCoordinates();
-    }
+    maybeCalculateTicksCoordinates();
 
     updateHaloHotspot();
   }
 
-  private void calculateTicksCoordinates() {
+  private void maybeCalculateTicksCoordinates() {
+    if (stepSize <= 0.0f) {
+      return;
+    }
+
     validateConfigurationIfDirty();
 
     int tickCount = (int) ((valueTo - valueFrom) / stepSize + 1);
@@ -1318,9 +1348,7 @@ protected void onDraw(@NonNull Canvas canvas) {
       validateConfigurationIfDirty();
 
       // Update the visible tick coordinates.
-      if (stepSize > 0.0f) {
-        calculateTicksCoordinates();
-      }
+      maybeCalculateTicksCoordinates();
     }
 
     super.onDraw(canvas);
@@ -1332,9 +1360,7 @@ protected void onDraw(@NonNull Canvas canvas) {
       drawActiveTrack(canvas, trackWidth, top);
     }
 
-    if (stepSize > 0.0f) {
-      drawTicks(canvas);
-    }
+    maybeDrawTicks(canvas);
 
     if ((thumbIsPressed || isFocused()) && isEnabled()) {
       maybeDrawHalo(canvas, trackWidth, top);
@@ -1395,7 +1421,11 @@ private void drawActiveTrack(@NonNull Canvas canvas, int width, int top) {
     canvas.drawLine(left, top, right, top, activeTrackPaint);
   }
 
-  private void drawTicks(@NonNull Canvas canvas) {
+  private void maybeDrawTicks(@NonNull Canvas canvas) {
+    if (!tickVisible || stepSize <= 0.0f) {
+      return;
+    }
+
     float[] activeRange = getActiveRange();
     int leftPivotIndex = pivotIndex(ticksCoordinates, activeRange[0]);
     int rightPivotIndex = pivotIndex(ticksCoordinates, activeRange[1]);

lib/java/com/google/android/material/slider/res-public/values/public.xml

@@ -27,6 +27,7 @@
   <public name="tickColor" type="attr" />
   <public name="tickColorActive" type="attr" />
   <public name="tickColorInactive" type="attr" />
+  <public name="tickVisible" type="attr" />
   <public name="trackColorActive" type="attr" />
   <public name="trackColorInactive" type="attr" />
   <public name="trackHeight" type="attr" />

lib/java/com/google/android/material/slider/res/values/attrs.xml

@@ -51,6 +51,8 @@
     <!-- The color of the slider's tick marks for the inactive portion of the track. Only used when
          the slider is in discrete mode. -->
     <attr name="tickColorInactive" format="color" />
+    <!-- Whether to show the tick marks. Only used when the slider is in discrete mode. -->
+    <attr name="tickVisible" format="boolean" />
     <!-- The color of the track. -->
     <attr name="trackColor" />
     <!-- The color of active portion of the track. -->