[Slider][A11y] Fix slider D-Pad keys to modify value instead of focus

Previously, Up/Down arrow keys navigated focus instead of changing the slider value. This change updates keyboard handling so all D-Pad keys modify the slider value: Up/Down increment/decrement the value, and Left/Right increment/decrement based on layout direction.

PiperOrigin-RevId: 821593460

Author: Material Design Team

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

@@ -3877,20 +3877,18 @@ private Float calculateIncrementForKey(int keyCode) {
     // Otherwise choose the smallest valid increment.
     float increment = isLongPress ? calculateStepIncrement(20) : calculateStepIncrement();
     switch (keyCode) {
+      // Numpad Plus == Shift + Equals, at least in AVD, so fall through.
+      case KeyEvent.KEYCODE_PLUS:
       case KeyEvent.KEYCODE_DPAD_UP:
-        return isVertical() ? increment : null;
+      case KeyEvent.KEYCODE_EQUALS:
+        return increment;
       case KeyEvent.KEYCODE_DPAD_DOWN:
-        return isVertical() ? -increment : null;
+      case KeyEvent.KEYCODE_MINUS:
+        return -increment;
       case KeyEvent.KEYCODE_DPAD_LEFT:
         return isRtl() ? increment : -increment;
       case KeyEvent.KEYCODE_DPAD_RIGHT:
         return isRtl() ? -increment : increment;
-      case KeyEvent.KEYCODE_MINUS:
-        return -increment;
-      case KeyEvent.KEYCODE_EQUALS:
-      // Numpad Plus == Shift + Equals, at least in AVD, so fall through.
-      case KeyEvent.KEYCODE_PLUS:
-        return increment;
       default:
         return null;
     }

lib/javatests/com/google/android/material/slider/SliderKeyTestCommon.java

@@ -126,30 +126,6 @@ public void testMoveThumbFocus_tab_correctThumbHasFocus() {
     sendKeyEventThereAndBack(tab, shiftTab);
   }
 
-  @Test
-  public void testFocusDefaultThumb_clickUpDPad_unhandled() {
-    slider.requestFocus();
-
-    KeyEventBuilder up = new KeyEventBuilder(KeyEvent.KEYCODE_DPAD_UP);
-    boolean handledDown = slider.dispatchKeyEvent(up.buildDown());
-    boolean handledUp = slider.dispatchKeyEvent(up.buildUp());
-
-    assertThat(handledDown).isFalse();
-    assertThat(handledUp).isFalse();
-  }
-
-  @Test
-  public void testFocusDefaultThumb_clickDownDPad_unhandled() {
-    slider.requestFocus();
-
-    KeyEventBuilder down = new KeyEventBuilder(KeyEvent.KEYCODE_DPAD_DOWN);
-    boolean handledDown = slider.dispatchKeyEvent(down.buildDown());
-    boolean handledUp = slider.dispatchKeyEvent(down.buildUp());
-
-    assertThat(handledDown).isFalse();
-    assertThat(handledUp).isFalse();
-  }
-
   @Test
   public void testFocusFirstThumb_shiftTab_unhandled() {
     slider.requestFocus();
@@ -179,6 +155,30 @@ public void testFocusLastThumb_tab_unhandled() {
     assertThat(handledUp).isFalse();
   }
 
+  @Test
+  public void testKeyPress_dPadUp_incrementsValue() {
+    slider.requestFocus();
+    slider.setValues(50f);
+    slider.setStepSize(1f);
+
+    KeyEventBuilder up = new KeyEventBuilder(KeyEvent.KEYCODE_DPAD_UP);
+    up.dispatchEvent(slider);
+
+    assertThat(slider.getValues().get(0)).isEqualTo(51f);
+  }
+
+  @Test
+  public void testKeyPress_dPadDown_decrementsValue() {
+    slider.requestFocus();
+    slider.setValues(50f);
+    slider.setStepSize(1f);
+
+    KeyEventBuilder down = new KeyEventBuilder(KeyEvent.KEYCODE_DPAD_DOWN);
+    down.dispatchEvent(slider);
+
+    assertThat(slider.getValues().get(0)).isEqualTo(49f);
+  }
+
   protected void sendKeyEventThereAndBack(KeyEventBuilder there, KeyEventBuilder back) {
     for (int i = 1; i < countTestValues(); i++) {
       there.dispatchEvent(slider);

lib/javatests/com/google/android/material/slider/SliderKeyTestLtr.java

@@ -72,4 +72,28 @@ public void testFocusThirdThumb_moveLeft_movesThirdThumbLeft() {
 
     assertThat(slider.getValues()).doesNotContain(3.0f);
   }
+
+  @Test
+  public void testKeyPress_dPadLeft_decrementsValue() {
+    slider.requestFocus();
+    slider.setValues(50f);
+    slider.setStepSize(1f);
+
+    KeyEventBuilder left = new KeyEventBuilder(KeyEvent.KEYCODE_DPAD_LEFT);
+    left.dispatchEvent(slider);
+
+    assertThat(slider.getValues().get(0)).isEqualTo(49f);
+  }
+
+  @Test
+  public void testKeyPress_dPadRight_incrementsValue() {
+    slider.requestFocus();
+    slider.setValues(50f);
+    slider.setStepSize(1f);
+
+    KeyEventBuilder right = new KeyEventBuilder(KeyEvent.KEYCODE_DPAD_RIGHT);
+    right.dispatchEvent(slider);
+
+    assertThat(slider.getValues().get(0)).isEqualTo(51f);
+  }
 }

lib/javatests/com/google/android/material/slider/SliderKeyTestRtl.java

@@ -91,4 +91,28 @@ public void testFocusThirdThumb_moveLeft_movesThirdThumbLeft() {
     // Moving left increments in RTL.
     assertThat(slider.getValues()).doesNotContain(3.0f);
   }
+
+  @Test
+  public void testKeyPress_dPadLeft_incrementsValue() {
+    slider.requestFocus();
+    slider.setValues(50f);
+    slider.setStepSize(1f);
+
+    KeyEventBuilder left = new KeyEventBuilder(KeyEvent.KEYCODE_DPAD_LEFT);
+    left.dispatchEvent(slider);
+
+    assertThat(slider.getValues().get(0)).isEqualTo(51f);
+  }
+
+  @Test
+  public void testKeyPress_dPadRight_decrementsValue() {
+    slider.requestFocus();
+    slider.setValues(50f);
+    slider.setStepSize(1f);
+
+    KeyEventBuilder right = new KeyEventBuilder(KeyEvent.KEYCODE_DPAD_RIGHT);
+    right.dispatchEvent(slider);
+
+    assertThat(slider.getValues().get(0)).isEqualTo(49f);
+  }
 }