Support aspect ratio change in PiP demo

For testing and demo purpose, currently support selecting from well
defined list of aspect ratio, include 21:9, 16:9, 1:1, 9:16 and 9:21

Video: http://recall/-/aaaaaabFQoRHlzixHdtY/gqFQI7mpeQ6EZZ5JibsV6R
Bug: 198643358
Test: Change aspect ratio within the app, see video
Change-Id: I0580dc45bf32e795fefd7d80f5183f268f810790

samples/ApiDemos/res/layout/picture_in_picture.xml

@@ -102,6 +102,24 @@
 
             </RadioGroup>
 
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:padding="8dp"
+                android:orientation="horizontal">
+
+                <TextView
+                  android:layout_width="wrap_content"
+                  android:layout_height="wrap_content"
+                  android:text="@string/label_aspect_ratio" />
+
+                <Spinner
+                    android:id="@+id/aspect_ratio"
+                    android:layout_width="0dp"
+                    android:layout_height="wrap_content"
+                    android:layout_weight="1" />
+            </LinearLayout>
+
             <Button
                 android:id="@+id/enter_pip_button"
                 android:layout_width="wrap_content"

samples/ApiDemos/res/layout/picture_in_picture_content.xml

@@ -14,6 +14,7 @@
   ~ See the License for the specific language governing permissions and
   ~ limitations under the License.
   -->
+<!-- Note that app:aspectRatio can be changed dynamically. -->
 <com.example.android.apis.view.FixedAspectRatioImageView
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"

samples/ApiDemos/res/values/strings.xml

@@ -74,6 +74,15 @@
     <string name="label_exit_position">Exit position</string>
     <string name="label_position_start">Start</string>
     <string name="label_position_end">End</string>
+    <string name="label_aspect_ratio">Aspect Ratio</string>
+    <!-- List of aspect ratio to demo, we use Rational.parseRational to parse what's inside () -->
+    <string-array name="aspect_ratio_list">
+        <item>Extreme wide (21/9)</item>
+        <item>Video (16/9)</item>
+        <item>Square (1/1)</item>
+        <item>Video call (9/16)</item>
+        <item>Extreme tall (9/21)</item>
+    </string-array>
 
     <string name="activity_keep_clear">App/Activity/Keep Clear Rects</string>
     <string name="keep_clear_property_set">

samples/ApiDemos/src/com/example/android/apis/app/PictureInPicture.java

@@ -39,14 +39,18 @@ import android.util.Rational;
 import android.view.Gravity;
 import android.view.View;
 import android.view.WindowManager;
+import android.widget.AdapterView;
+import android.widget.ArrayAdapter;
 import android.widget.CompoundButton;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.RadioGroup;
+import android.widget.Spinner;
 import android.widget.Switch;
 import android.window.OnBackInvokedDispatcher;
 
 import com.example.android.apis.R;
+import com.example.android.apis.view.FixedAspectRatioImageView;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -57,6 +61,7 @@ public class PictureInPicture extends Activity {
     private static final String EXTRA_ENABLE_SEAMLESS_RESIZE = "seamless_resize";
     private static final String EXTRA_ENTER_PIP_ON_BACK = "enter_pip_on_back";
     private static final String EXTRA_CURRENT_POSITION = "current_position";
+    private static final String EXTRA_ASPECT_RATIO = "aspect_ratio";
 
     private static final int TABLET_BREAK_POINT_DP = 700;
 
@@ -95,13 +100,14 @@ public class PictureInPicture extends Activity {
             (v, id) -> updateContentPosition(id);
 
     private LinearLayout mContainer;
-    private ImageView mImageView;
+    private FixedAspectRatioImageView mImageView;
     private View mControlGroup;
     private Switch mAutoPipToggle;
     private Switch mSourceRectHintToggle;
     private Switch mSeamlessResizeToggle;
     private Switch mEnterPipOnBackToggle;
     private RadioGroup mCurrentPositionGroup;
+    private Spinner mAspectRatioSpinner;
     private List<RemoteAction> mPipActions;
     private RemoteAction mCloseAction;
 
@@ -119,6 +125,13 @@ public class PictureInPicture extends Activity {
         mSeamlessResizeToggle = findViewById(R.id.seamless_resize_toggle);
         mEnterPipOnBackToggle = findViewById(R.id.enter_pip_on_back);
         mCurrentPositionGroup = findViewById(R.id.current_position);
+        mAspectRatioSpinner = findViewById(R.id.aspect_ratio);
+
+        // Initiate views if applicable
+        final ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
+                R.array.aspect_ratio_list, android.R.layout.simple_spinner_item);
+        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+        mAspectRatioSpinner.setAdapter(adapter);
 
         // Attach listeners
         mImageView.addOnLayoutChangeListener(mOnLayoutChangeListener);
@@ -135,6 +148,22 @@ public class PictureInPicture extends Activity {
                     }
                 });
         mCurrentPositionGroup.setOnCheckedChangeListener(mOnPositionChangedListener);
+        mAspectRatioSpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
+            @Override
+            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
+                final String rawText = parent.getItemAtPosition(position).toString();
+                final String textToParse = rawText.substring(
+                        rawText.indexOf('(') + 1,
+                        rawText.indexOf(')'));
+                mImageView.addOnLayoutChangeListener(mOnLayoutChangeListener);
+                mImageView.setAspectRatio(Rational.parseRational(textToParse));
+            }
+
+            @Override
+            public void onNothingSelected(AdapterView<?> parent) {
+                // Do nothing.
+            }
+        });
         findViewById(R.id.enter_pip_button).setOnClickListener(v -> enterPictureInPictureMode());
         findViewById(R.id.enter_content_pip_button).setOnClickListener(v -> enterContentPip());
 
@@ -152,6 +181,7 @@ public class PictureInPicture extends Activity {
                 ? R.id.radio_current_end
                 : R.id.radio_current_start;
         mCurrentPositionGroup.check(positionId);
+        mAspectRatioSpinner.setSelection(1);
 
         updateLayout(getResources().getConfiguration());
     }

samples/ApiDemos/src/com/example/android/apis/view/FixedAspectRatioImageView.java

@@ -29,7 +29,7 @@ import com.example.android.apis.R;
  * one of the dimension is in exact while the other one in wrap_content size mode.
  */
 public class FixedAspectRatioImageView extends ImageView {
-    private final Rational mAspectRatio;
+    private Rational mAspectRatio;
 
     public FixedAspectRatioImageView(Context context, AttributeSet attrs) {
         super(context, attrs);
@@ -43,6 +43,13 @@ public class FixedAspectRatioImageView extends ImageView {
         }
     }
 
+    public void setAspectRatio(Rational aspectRatio) {
+        if (!mAspectRatio.equals(aspectRatio)) {
+            mAspectRatio = aspectRatio;
+            requestLayout();
+        }
+    }
+
     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);