Fix preview image alignment issue due to clip padding.

CaptionPropertiesFragment is using a non-standard way to display preview
images. Changed to use LayoutPreference.

Bug: 132797057
Test: visual
Change-Id: I92bfd38e2880226d7385e98ed871dad4e1f30e42

res/layout/captioning_preview.xml

@@ -15,41 +15,32 @@
      limitations under the License.
 -->
 
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+<FrameLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/preview_viewport"
+    android:clipToPadding="true"
+    android:clipChildren="true"
     android:layout_width="match_parent"
-    android:layout_height="match_parent"
+    android:layout_height="wrap_content">
-    android:orientation="vertical" >
+
+    <ImageView
+        android:layout_width="match_parent"
+        android:layout_height="@dimen/captioning_preview_height"
+        android:contentDescription="@null"
+        android:scaleType="centerCrop"
+        android:src="@drawable/caption_background"/>
 
     <FrameLayout
-        android:id="@+id/preview_viewport"
+        android:id="@+id/preview_window"
         android:layout_width="match_parent"
-        android:layout_height="@dimen/captioning_preview_height" >
+        android:layout_height="wrap_content"
+        android:layout_gravity="bottom|start"
+        android:padding="16dp">
 
-        <ImageView
+        <com.android.internal.widget.SubtitleView
-            android:layout_width="match_parent"
+            android:id="@+id/preview_text"
-            android:layout_height="match_parent"
+            android:layout_width="wrap_content"
-            android:contentDescription="@null"
-            android:scaleType="centerCrop"
-            android:src="@drawable/caption_background" />
-
-        <FrameLayout
-            android:id="@+id/preview_window"
-            android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:layout_gravity="bottom|start"
+            android:text="@string/captioning_preview_text"/>
-            android:padding="16dp" >
-
-            <com.android.internal.widget.SubtitleView
-                android:id="@+id/preview_text"
-                android:layout_width="wrap_content"
-                android:layout_height="wrap_content"
-                android:text="@string/captioning_preview_text" />
-        </FrameLayout>
     </FrameLayout>
-
+</FrameLayout>
-    <FrameLayout
-        android:id="@+id/properties_fragment"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent" />
-
-</LinearLayout>

res/layout/magnification_video_preference.xml

@@ -16,7 +16,9 @@
 <RelativeLayout
     xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
-    android:layout_height="wrap_content">
+    android:layout_height="wrap_content"
+    android:clipChildren="true"
+    android:clipToPadding="true">
 
     <ImageView
         android:id="@+id/video_background"

res/xml/captioning_settings.xml

@@ -21,6 +21,12 @@
     android:key="captioning_preference_screen"
     android:title="@string/accessibility_captioning_title" >
 
+    <com.android.settingslib.widget.LayoutPreference
+        android:key="caption_preview"
+        android:title="@string/summary_placeholder"
+        android:layout="@layout/captioning_preview"
+        settings:searchable="false"/>
+
     <PreferenceCategory
         android:key="standard"
         android:title="@string/captioning_standard_options_title" >

src/com/android/settings/accessibility/CaptionPropertiesFragment.java

@@ -22,13 +22,8 @@ import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Color;
 import android.os.Bundle;
-import android.preference.PreferenceFrameLayout;
 import android.provider.Settings;
-import android.view.LayoutInflater;
 import android.view.View;
-import android.view.View.OnLayoutChangeListener;
-import android.view.ViewGroup;
-import android.view.ViewGroup.LayoutParams;
 import android.view.accessibility.CaptioningManager;
 import android.view.accessibility.CaptioningManager.CaptionStyle;
 
@@ -46,6 +41,7 @@ import com.android.settings.widget.SwitchBar;
 import com.android.settings.widget.ToggleSwitch;
 import com.android.settings.widget.ToggleSwitch.OnBeforeCheckedChangeListener;
 import com.android.settingslib.accessibility.AccessibilityUtils;
+import com.android.settingslib.widget.LayoutPreference;
 
 import java.util.Locale;
 
@@ -54,6 +50,7 @@ import java.util.Locale;
  */
 public class CaptionPropertiesFragment extends SettingsPreferenceFragment
         implements OnPreferenceChangeListener, OnValueChangedListener {
+    private static final String PREF_CAPTION_PREVIEW = "caption_preview";
     private static final String PREF_BACKGROUND_COLOR = "captioning_background_color";
     private static final String PREF_BACKGROUND_OPACITY = "captioning_background_opacity";
     private static final String PREF_FOREGROUND_COLOR = "captioning_foreground_color";
@@ -115,43 +112,6 @@ public class CaptionPropertiesFragment extends SettingsPreferenceFragment
         installUpdateListeners();
     }
 
-    @Override
-    public View onCreateView(
-            LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        final View rootView = inflater.inflate(R.layout.captioning_preview, container, false);
-
-        // We have to do this now because PreferenceFrameLayout looks at it
-        // only when the view is added.
-        if (container instanceof PreferenceFrameLayout) {
-            ((PreferenceFrameLayout.LayoutParams) rootView.getLayoutParams()).removeBorders = true;
-        }
-
-        final View content = super.onCreateView(inflater, container, savedInstanceState);
-        ((ViewGroup) rootView.findViewById(R.id.properties_fragment)).addView(
-                content, LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
-
-        return rootView;
-    }
-
-    @Override
-    public void onViewCreated(View view, Bundle savedInstanceState) {
-        super.onViewCreated(view, savedInstanceState);
-
-        final boolean enabled = mCaptioningManager.isEnabled();
-        mPreviewText = (SubtitleView) view.findViewById(R.id.preview_text);
-        mPreviewText.setVisibility(enabled ? View.VISIBLE : View.INVISIBLE);
-
-        mPreviewWindow = view.findViewById(R.id.preview_window);
-        mPreviewViewport = view.findViewById(R.id.preview_viewport);
-        mPreviewViewport.addOnLayoutChangeListener(new OnLayoutChangeListener() {
-            @Override
-            public void onLayoutChange(View v, int left, int top, int right, int bottom,
-                    int oldLeft, int oldTop, int oldRight, int oldBottom) {
-                refreshPreviewText();
-            }
-        });
-    }
-
     @Override
     public void onActivityCreated(Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);
@@ -263,6 +223,19 @@ public class CaptionPropertiesFragment extends SettingsPreferenceFragment
     }
 
     private void initializeAllPreferences() {
+        final LayoutPreference captionPreview = findPreference(PREF_CAPTION_PREVIEW);
+
+        final boolean enabled = mCaptioningManager.isEnabled();
+        mPreviewText = captionPreview.findViewById(R.id.preview_text);
+        mPreviewText.setVisibility(enabled ? View.VISIBLE : View.INVISIBLE);
+
+        mPreviewWindow = captionPreview.findViewById(R.id.preview_window);
+
+        mPreviewViewport = captionPreview.findViewById(R.id.preview_viewport);
+        mPreviewViewport.addOnLayoutChangeListener(
+                (v, left, top, right, bottom, oldLeft, oldTop, oldRight, oldBottom)
+                        -> refreshPreviewText());
+
         mLocale = (LocalePreference) findPreference(PREF_LOCALE);
         mFontSize = (ListPreference) findPreference(PREF_FONT_SIZE);
 
@@ -370,9 +343,9 @@ public class CaptionPropertiesFragment extends SettingsPreferenceFragment
     /**
      * Unpack the specified color value and update the preferences.
      *
-     * @param color color preference
+     * @param color   color preference
      * @param opacity opacity preference
-     * @param value packed value
+     * @param value   packed value
      */
     private void parseColorOpacity(ColorPreference color, ColorPreference opacity, int value) {
         final int colorValue;