[TimePicker][A11y] Add keyboard support to clock input mode

Enables focus on the `ClockFaceView` and implements `onKeyDown` to allow users to navigate between clock values using DPAD keys. DPAD_RIGHT/UP increments the selected value, while DPAD_LEFT/DOWN decrements it.

PiperOrigin-RevId: 796951982

Author: Material Design Team

lib/java/com/google/android/material/timepicker/ClockFaceView.java

@@ -29,6 +29,7 @@
 import android.content.res.ColorStateList;
 import android.content.res.Resources;
 import android.content.res.TypedArray;
+import android.graphics.Outline;
 import android.graphics.RadialGradient;
 import android.graphics.Rect;
 import android.graphics.RectF;
@@ -39,9 +40,11 @@
 import android.util.AttributeSet;
 import android.util.DisplayMetrics;
 import android.util.SparseArray;
+import android.view.KeyEvent;
 import android.view.LayoutInflater;
 import android.view.MotionEvent;
 import android.view.View;
+import android.view.ViewOutlineProvider;
 import android.view.ViewTreeObserver.OnPreDrawListener;
 import android.view.accessibility.AccessibilityNodeInfo;
 import android.widget.TextView;
@@ -92,6 +95,8 @@ class ClockFaceView extends RadialViewGroup implements OnRotateListener {
 
   private final ColorStateList textColor;
 
+  private OnEnterKeyPressedListener onEnterKeyPressedListener;
+
   public ClockFaceView(@NonNull Context context) {
     this(context, null);
   }
@@ -150,8 +155,18 @@ public boolean onPreDraw() {
               }
             });
 
-    setFocusable(false);
     a.recycle();
+
+    setOutlineProvider(
+        new ViewOutlineProvider() {
+          @Override
+          public void getOutline(View view, Outline outline) {
+            outline.setOval(0, 0, view.getWidth(), view.getHeight());
+          }
+        });
+    setFocusable(true);
+    setClipToOutline(true);
+
     valueAccessibilityDelegate =
         new AccessibilityDelegateCompat() {
           @Override
@@ -167,7 +182,7 @@ public void onInitializeAccessibilityNodeInfo(
                 CollectionItemInfoCompat.obtain(
                     /* rowIndex= */ 0,
                     /* rowSpan= */ 1,
-                    /* columnIndex =*/ index,
+                    /* columnIndex= */ index,
                     /* columnSpan= */ 1,
                     /* heading= */ false,
                     /* selected= */ host.isSelected()));
@@ -375,6 +390,57 @@ protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
     super.onMeasure(spec, spec);
   }
 
+  private int getSelectedIndex() {
+    for (int i = 0; i < textViewPool.size(); i++) {
+      TextView textView = textViewPool.valueAt(i);
+      if (textView.isSelected()) {
+        return (int) textView.getTag(R.id.material_value_index);
+      }
+    }
+    return -1;
+  }
+
+  @Override
+  public boolean onKeyDown(int keyCode, KeyEvent event) {
+    int selectedIndex = getSelectedIndex();
+    if (!isShown() || selectedIndex == -1) {
+      return super.onKeyDown(keyCode, event);
+    }
+
+    int nextIndex;
+    switch (keyCode) {
+      case KeyEvent.KEYCODE_DPAD_RIGHT:
+      case KeyEvent.KEYCODE_DPAD_UP:
+        nextIndex = (selectedIndex + 1) % values.length;
+        break;
+      case KeyEvent.KEYCODE_DPAD_LEFT:
+      case KeyEvent.KEYCODE_DPAD_DOWN:
+        nextIndex = (selectedIndex - 1 + values.length) % values.length;
+        break;
+      case KeyEvent.KEYCODE_ENTER:
+      case KeyEvent.KEYCODE_DPAD_CENTER:
+        if (onEnterKeyPressedListener != null) {
+          onEnterKeyPressedListener.onEnterKeyPressed();
+        }
+        return true;
+      default:
+        return super.onKeyDown(keyCode, event);
+    }
+
+    if (nextIndex != selectedIndex) {
+      int level = (nextIndex / INITIAL_CAPACITY) + LEVEL_1;
+      if (level != getCurrentLevel()) {
+        setCurrentLevel(level);
+      }
+
+      float rotation = (nextIndex % INITIAL_CAPACITY) * (360f / INITIAL_CAPACITY);
+      setHandRotation(rotation);
+      return true;
+    }
+
+    return super.onKeyDown(keyCode, event);
+  }
+
   private static float max3(float a, float b, float c) {
     return max(max(a, b), c);
   }
@@ -387,4 +453,14 @@ int getCurrentLevel() {
   void setCurrentLevel(@Level int level) {
     clockHandView.setCurrentLevel(level);
   }
+
+  public void setOnEnterKeyPressedListener(OnEnterKeyPressedListener onEnterKeyPressedListener) {
+    this.onEnterKeyPressedListener = onEnterKeyPressedListener;
+  }
+
+  /** Listener interface for enter key press events on the clock face. */
+  interface OnEnterKeyPressedListener {
+    /** Called when the enter key is pressed. */
+    void onEnterKeyPressed();
+  }
 }

lib/java/com/google/android/material/timepicker/TimePickerView.java

@@ -123,6 +123,13 @@ public TimePickerView(Context context, @Nullable AttributeSet attrs, int defStyl
     hourView = findViewById(R.id.material_hour_tv);
     clockHandView = findViewById(R.id.material_clock_hand);
 
+    clockFace.setOnEnterKeyPressedListener(
+        () -> {
+          if (hourView.isChecked() && onSelectionChangeListener != null) {
+            onSelectionChangeListener.onSelectionChanged(MINUTE);
+          }
+        });
+
     setupDoubleTap();
 
     setUpDisplay();