Add PictureInPictureParams#isSameAspectRatio [1/N]

This is to replace the float number check when comparing the given Rect
over aspect ratio. In this new static method, we allow for rounding
errors on width / height.

CTS tests have been updated to use and test this method.

What's next:
- Move the aspect ratio check from WMShell to Activity

Flag: EXEMPT refactor
Bug: 352118806
Test: atest CtsWindowManagerDeviceOther:PictureInPictureParamsTest
Change-Id: I205abb2b6cf4414be9ad8700ed1adf7fcea50ad5

2 files changed, 28 insertions, 0 deletions

diff --git a/core/api/test-current.txt b/core/api/test-current.txt
index 44c4ab4e1b57..1e51fea849c9 100644
--- a/core/api/test-current.txt
+++ b/core/api/test-current.txt
@@ -423,6 +423,7 @@ package android.app {
   public final class PictureInPictureParams implements android.os.Parcelable {
     method public float getAspectRatioFloat();
     method public float getExpandedAspectRatioFloat();
+    method public static boolean isSameAspectRatio(@NonNull android.graphics.Rect, @NonNull android.util.Rational);
   }
 
   public final class PictureInPictureUiState implements android.os.Parcelable {
diff --git a/core/java/android/app/PictureInPictureParams.java b/core/java/android/app/PictureInPictureParams.java
index 96d874ee110b..afe915eece26 100644
--- a/core/java/android/app/PictureInPictureParams.java
+++ b/core/java/android/app/PictureInPictureParams.java
@@ -654,6 +654,33 @@ public final class PictureInPictureParams implements Parcelable {
                 && !hasSetSubtitle() && mIsLaunchIntoPip == null;
     }
 
+    /**
+     * Compare a given {@link Rect} against the aspect ratio, with rounding error tolerance.
+     * @param bounds The {@link Rect} represents the source rect hint, this check is not needed
+     *               if app provides a null source rect hint.
+     * @param aspectRatio {@link Rational} representation of aspect ratio, this check is not needed
+     *                    if app provides a null aspect ratio.
+     * @return {@code true} if the given {@link Rect} matches the aspect ratio.
+     * @hide
+     */
+    @SuppressWarnings("UnflaggedApi")
+    @TestApi
+    public static boolean isSameAspectRatio(@NonNull Rect bounds, @NonNull Rational aspectRatio) {
+        // Validations
+        if (bounds.isEmpty() || aspectRatio.floatValue() <= 0) {
+            return false;
+        }
+        // Check against both the width and height.
+        final int exactWidth = (aspectRatio.getNumerator() * bounds.height())
+                / aspectRatio.getDenominator();
+        if (Math.abs(exactWidth - bounds.width()) <= 1) {
+            return true;
+        }
+        final int exactHeight = (aspectRatio.getDenominator() * bounds.width())
+                / aspectRatio.getNumerator();
+        return Math.abs(exactHeight - bounds.height()) <= 1;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;